Protein encoded by the bcl-1 gene which plays a critical role in regulating the cell cycle. Overexpression of cyclin D1 is the result of bcl-1 rearrangement, a t(11;14) translocation, and is implicated in various neoplasms.
A cyclin D subtype which is regulated by GATA4 TRANSCRIPTION FACTOR. Experiments using KNOCKOUT MICE suggest a role for cyclin D2 in granulosa cell proliferation and gonadal development.
A broadly expressed type D cyclin. Experiments using KNOCKOUT MICE suggest a role for cyclin D3 in LYMPHOCYTE development.
A cyclin subtype that has specificity for CDC2 PROTEIN KINASE and CYCLIN-DEPENDENT KINASE 2. It plays a role in progression of the CELL CYCLE through G1/S and G2/M phase transitions.
A cyclin subtype that is specific for CYCLIN-DEPENDENT KINASE 4 and CYCLIN-DEPENDENT KINASE 6. Unlike most cyclins, cyclin D expression is not cyclical, but rather it is expressed in response to proliferative signals. Cyclin D may therefore play a role in cellular responses to mitogenic signals.
A 50-kDa protein that complexes with CYCLIN-DEPENDENT KINASE 2 in the late G1 phase of the cell cycle.
A cyclin subtype that is transported into the CELL NUCLEUS at the end of the G2 PHASE. It stimulates the G2/M phase transition by activating CDC2 PROTEIN KINASE.
A cyclin B subtype that colocalizes with MICROTUBULES during INTERPHASE and is transported into the CELL NUCLEUS at the end of the G2 PHASE.
A cyclin A subtype primarily found in male GERM CELLS. It may play a role in the passage of SPERMATOCYTES into meiosis I.
A large family of regulatory proteins that function as accessory subunits to a variety of CYCLIN-DEPENDENT KINASES. They generally function as ENZYME ACTIVATORS that drive the CELL CYCLE through transitions between phases. A subset of cyclins may also function as transcriptional regulators.
A widely-expressed cyclin A subtype that functions during the G1/S and G2/M transitions of the CELL CYCLE.
Cyclin-dependent kinase 4 is a key regulator of G1 PHASE of the CELL CYCLE. It partners with CYCLIN D to phosphorylate RETINOBLASTOMA PROTEIN. CDK4 activity is inhibited by CYCLIN-DEPENDENT KINASE INHIBITOR P16.
Protein kinases that control cell cycle progression in all eukaryotes and require physical association with CYCLINS to achieve full enzymatic activity. Cyclin-dependent kinases are regulated by phosphorylation and dephosphorylation events.
A cyclin G subtype that is constitutively expressed throughout the cell cycle. Cyclin G1 is considered a major transcriptional target of TUMOR SUPPRESSOR PROTEIN P53 and is highly induced in response to DNA damage.
A cyclin subtype that is found associated with CYCLIN-DEPENDENT KINASE 5; cyclin G associated kinase, and PROTEIN PHOSPHATASE 2.
The complex series of phenomena, occurring between the end of one CELL DIVISION and the end of the next, by which cellular material is duplicated and then divided between two daughter cells. The cell cycle includes INTERPHASE, which includes G0 PHASE; G1 PHASE; S PHASE; and G2 PHASE, and CELL DIVISION PHASE.
A key regulator of CELL CYCLE progression. It partners with CYCLIN E to regulate entry into S PHASE and also interacts with CYCLIN A to phosphorylate RETINOBLASTOMA PROTEIN. Its activity is inhibited by CYCLIN-DEPENDENT KINASE INHIBITOR P27 and CYCLIN-DEPENDENT KINASE INHIBITOR P21.
The period of the CELL CYCLE preceding DNA REPLICATION in S PHASE. Subphases of G1 include "competence" (to respond to growth factors), G1a (entry into G1), G1b (progression), and G1c (assembly). Progression through the G1 subphases is effected by limiting growth factors, nutrients, or inhibitors.
The B-cell leukemia/lymphoma-1 genes, associated with various neoplasms when overexpressed. Overexpression results from the t(11;14) translocation, which is characteristic of mantle zone-derived B-cell lymphomas. The human c-bcl-1 gene is located at 11q13 on the long arm of chromosome 11.
A cyclin subtype that binds to the CYCLIN-DEPENDENT KINASE 3 and CYCLIN-DEPENDENT KINASE 8. Cyclin C plays a dual role as a transcriptional regulator and a G1 phase CELL CYCLE regulator.
Product of the retinoblastoma tumor suppressor gene. It is a nuclear phosphoprotein hypothesized to normally act as an inhibitor of cell proliferation. Rb protein is absent in retinoblastoma cell lines. It also has been shown to form complexes with the adenovirus E1A protein, the SV40 T antigen, and the human papilloma virus E7 protein.
A family of cell cycle-dependent kinases that are related in structure to CDC28 PROTEIN KINASE; S CEREVISIAE; and the CDC2 PROTEIN KINASE found in mammalian species.
A cyclin B subtype that colocalizes with GOLGI APPARATUS during INTERPHASE and is transported into the CELL NUCLEUS at the end of the G2 PHASE.
A cyclin subtype that is found associated with CYCLIN-DEPENDENT KINASE 9. Unlike traditional cyclins, which regulate the CELL CYCLE, type T cyclins appear to regulate transcription and are components of positive transcriptional elongation factor B.
Proteins coded by oncogenes. They include proteins resulting from the fusion of an oncogene and another gene (ONCOGENE PROTEINS, FUSION).
A cyclin subtype that is found as a component of a heterotrimeric complex containing cyclin-dependent kinase 7 and CDK-activating kinase assembly factor. The complex plays a role in cellular proliferation by phosphorylating several CYCLIN DEPENDENT KINASES at specific regulatory threonine sites.
Proteins that control the CELL DIVISION CYCLE. This family of proteins includes a wide variety of classes, including CYCLIN-DEPENDENT KINASES, mitogen-activated kinases, CYCLINS, and PHOSPHOPROTEIN PHOSPHATASES as well as their putative substrates such as chromatin-associated proteins, CYTOSKELETAL PROTEINS, and TRANSCRIPTION FACTORS.
Phase of the CELL CYCLE following G1 and preceding G2 when the entire DNA content of the nucleus is replicated. It is achieved by bidirectional replication at multiple sites along each chromosome.
An unusual cyclin subtype that is found highly expressed in terminally differentiated cells. Unlike conventional cyclins increased expression of cyclin G2 is believed to cause a withdrawal of cells from the CELL CYCLE.
Phosphoprotein with protein kinase activity that functions in the G2/M phase transition of the CELL CYCLE. It is the catalytic subunit of the MATURATION-PROMOTING FACTOR and complexes with both CYCLIN A and CYCLIN B in mammalian cells. The maximal activity of cyclin-dependent kinase 1 is achieved when it is fully dephosphorylated.
All of the processes involved in increasing CELL NUMBER including CELL DIVISION.
A cyclin-dependent kinase inhibitor that mediates TUMOR SUPPRESSOR PROTEIN P53-dependent CELL CYCLE arrest. p21 interacts with a range of CYCLIN-DEPENDENT KINASES and associates with PROLIFERATING CELL NUCLEAR ANTIGEN and CASPASE 3.
The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.
The fission of a CELL. It includes CYTOKINESIS, when the CYTOPLASM of a cell is divided, and CELL NUCLEUS DIVISION.
A group of enzymes that catalyzes the phosphorylation of serine or threonine residues in proteins, with ATP or other nucleotides as phosphate donors.
A cell line derived from cultured tumor cells.
A cyclin-dependent kinase inhibitor that coordinates the activation of CYCLIN and CYCLIN-DEPENDENT KINASES during the CELL CYCLE. It interacts with active CYCLIN D complexed to CYCLIN-DEPENDENT KINASE 4 in proliferating cells, while in arrested cells it binds and inhibits CYCLIN E complexed to CYCLIN-DEPENDENT KINASE 2.
Products of proto-oncogenes. Normally they do not have oncogenic or transforming properties, but are involved in the regulation or differentiation of cell growth. They often have protein kinase activity.
Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action in neoplastic tissue.
Proteins that are normally involved in holding cellular growth in check. Deficiencies or abnormalities in these proteins may lead to unregulated cell growth and tumor development.
A cyclin subtype that is found abundantly in post-mitotic tissues. In contrast to the classical cyclins, its level does not fluctuate during the cell cycle.
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
A type of CELL NUCLEUS division by means of which the two daughter nuclei normally receive identical complements of the number of CHROMOSOMES of the somatic cells of the species.
Histochemical localization of immunoreactive substances using labeled antibodies as reagents.
Cells grown in vitro from neoplastic tissue. If they can be established as a TUMOR CELL LINE, they can be propagated in cell culture indefinitely.
A quiescent state of cells during G1 PHASE.
A form of non-Hodgkin lymphoma having a usually diffuse pattern with both small and medium lymphocytes and small cleaved cells. It accounts for about 5% of adult non-Hodgkin lymphomas in the United States and Europe. The majority of mantle-cell lymphomas are associated with a t(11;14) translocation resulting in overexpression of the CYCLIN D1 gene (GENES, BCL-1).
The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.
A negative regulatory effect on physiological processes at the molecular, cellular, or systemic level. At the molecular level, the major regulatory sites include membrane receptors, genes (GENE EXPRESSION REGULATION), mRNAs (RNA, MESSENGER), and proteins.
A product of the p16 tumor suppressor gene (GENES, P16). It is also called INK4 or INK4A because it is the prototype member of the INK4 CYCLIN-DEPENDENT KINASE INHIBITORS. This protein is produced from the alpha mRNA transcript of the p16 gene. The other gene product, produced from the alternatively spliced beta transcript, is TUMOR SUPPRESSOR PROTEIN P14ARF. Both p16 gene products have tumor suppressor functions.
Identification of proteins or peptides that have been electrophoretically separated by blot transferring from the electrophoresis gel to strips of nitrocellulose paper, followed by labeling with antibody probes.
DNA sequences which are recognized (directly or indirectly) and bound by a DNA-dependent RNA polymerase during the initiation of transcription. Highly conserved sequences within the promoter include the Pribnow box in bacteria and the TATA BOX in eukaryotes.
The uptake of naked or purified DNA by CELLS, usually meaning the process as it occurs in eukaryotic cells. It is analogous to bacterial transformation (TRANSFORMATION, BACTERIAL) and both are routinely employed in GENE TRANSFER TECHNIQUES.
Nuclear antigen with a role in DNA synthesis, DNA repair, and cell cycle progression. PCNA is required for the coordinated synthesis of both leading and lagging strands at the replication fork during DNA replication. PCNA expression correlates with the proliferation activity of several malignant and non-malignant cell types.
Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (CELL NUCLEOLUS). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the ENDOPLASMIC RETICULUM. A cell may contain more than one nucleus. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)
One of the mechanisms by which CELL DEATH occurs (compare with NECROSIS and AUTOPHAGOCYTOSIS). Apoptosis is the mechanism responsible for the physiological deletion of cells and appears to be intrinsically programmed. It is characterized by distinctive morphologic changes in the nucleus and cytoplasm, chromatin cleavage at regularly spaced sites, and the endonucleolytic cleavage of genomic DNA; (DNA FRAGMENTATION); at internucleosomal sites. This mode of cell death serves as a balance to mitosis in regulating the size of animal tissues and in mediating pathologic processes associated with tumor growth.
Established cell cultures that have the potential to propagate indefinitely.
Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.
The period of the CELL CYCLE following DNA synthesis (S PHASE) and preceding M PHASE (cell division phase). The CHROMOSOMES are tetraploid in this point.
A family of basic helix-loop-helix transcription factors that control expression of a variety of GENES involved in CELL CYCLE regulation. E2F transcription factors typically form heterodimeric complexes with TRANSCRIPTION FACTOR DP1 or transcription factor DP2, and they have N-terminal DNA binding and dimerization domains. E2F transcription factors can act as mediators of transcriptional repression or transcriptional activation.
A multi-functional catenin that participates in CELL ADHESION and nuclear signaling. Beta catenin binds CADHERINS and helps link their cytoplasmic tails to the ACTIN in the CYTOSKELETON via ALPHA CATENIN. It also serves as a transcriptional co-activator and downstream component of WNT PROTEIN-mediated SIGNAL TRANSDUCTION PATHWAYS.
Cyclin-dependent kinase 6 associates with CYCLIN D and phosphorylates RETINOBLASTOMA PROTEIN during G1 PHASE of the CELL CYCLE. It helps regulate the transition to S PHASE and its kinase activity is inhibited by CYCLIN-DEPENDENT KINASE INHIBITOR P18.
Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.
Cell lines whose original growing procedure consisted being transferred (T) every 3 days and plated at 300,000 cells per plate (J Cell Biol 17:299-313, 1963). Lines have been developed using several different strains of mice. Tissues are usually fibroblasts derived from mouse embryos but other types and sources have been developed as well. The 3T3 lines are valuable in vitro host systems for oncogenic virus transformation studies, since 3T3 cells possess a high sensitivity to CONTACT INHIBITION.
The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.
A glycogen synthase kinase that was originally described as a key enzyme involved in glycogen metabolism. It regulates a diverse array of functions such as CELL DIVISION, microtubule function and APOPTOSIS.
A CELL CYCLE and tumor growth marker which can be readily detected using IMMUNOCYTOCHEMISTRY methods. Ki-67 is a nuclear antigen present only in the nuclei of cycling cells.
Cell changes manifested by escape from control mechanisms, increased growth potential, alterations in the cell surface, karyotypic abnormalities, morphological and biochemical deviations from the norm, and other attributes conferring the ability to invade, metastasize, and kill.
The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.
Tumors or cancer of the human BREAST.
A family of proteins that share the F-BOX MOTIF and are involved in protein-protein interactions. They play an important role in process of protein ubiquition by associating with a variety of substrates and then associating into SCF UBIQUITIN LIGASE complexes. They are held in the ubiquitin-ligase complex via binding to SKP DOMAIN PROTEINS.
Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.
Nuclear phosphoprotein encoded by the p53 gene (GENES, P53) whose normal function is to control CELL PROLIFERATION and APOPTOSIS. A mutant or absent p53 protein has been found in LEUKEMIA; OSTEOSARCOMA; LUNG CANCER; and COLORECTAL CANCER.
A variation of the PCR technique in which cDNA is made from RNA via reverse transcription. The resultant cDNA is then amplified using standard PCR protocols.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
Proteins which bind to DNA. The family includes proteins which bind to both double- and single-stranded DNA and also includes specific DNA binding proteins in serum which can be used as markers for malignant diseases.
Small double-stranded, non-protein coding RNAs (21-31 nucleotides) involved in GENE SILENCING functions, especially RNA INTERFERENCE (RNAi). Endogenously, siRNAs are generated from dsRNAs (RNA, DOUBLE-STRANDED) by the same ribonuclease, Dicer, that generates miRNAs (MICRORNAS). The perfect match of the siRNAs' antisense strand to their target RNAs mediates RNAi by siRNA-guided RNA cleavage. siRNAs fall into different classes including trans-acting siRNA (tasiRNA), repeat-associated RNA (rasiRNA), small-scan RNA (scnRNA), and Piwi protein-interacting RNA (piRNA) and have different specific gene silencing functions.
Cellular DNA-binding proteins encoded by the c-myc genes. They are normally involved in nucleic acid metabolism and in mediating the cellular response to growth factors. Elevated and deregulated (constitutive) expression of c-myc proteins can cause tumorigenesis.
A continuous cell line of high contact-inhibition established from NIH Swiss mouse embryo cultures. The cells are useful for DNA transfection and transformation studies. (From ATCC [Internet]. Virginia: American Type Culture Collection; c2002 [cited 2002 Sept 26]. Available from http://www.atcc.org/)
An E2F transcription factor that interacts directly with RETINOBLASTOMA PROTEIN and CYCLIN A and activates GENETIC TRANSCRIPTION required for CELL CYCLE entry and DNA synthesis. E2F1 is involved in DNA REPAIR and APOPTOSIS.
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
Proteins found in the nucleus of a cell. Do not confuse with NUCLEOPROTEINS which are proteins conjugated with nucleic acids, that are not necessarily present in the nucleus.
Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.
Compounds or agents that combine with an enzyme in such a manner as to prevent the normal substrate-enzyme combination and the catalytic reaction.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
Technique using an instrument system for making, processing, and displaying one or more measurements on individual cells obtained from a cell suspension. Cells are usually stained with one or more fluorescent dyes specific to cell components of interest, e.g., DNA, and fluorescence of each cell is measured as it rapidly transverses the excitation beam (laser or mercury arc lamp). Fluorescence provides a quantitative measure of various biochemical and biophysical properties of the cell, as well as a basis for cell sorting. Other measurable optical parameters include light absorption and light scattering, the latter being applicable to the measurement of cell size, shape, density, granularity, and stain uptake.
A transcription factor that possesses DNA-binding and E2F-binding domains but lacks a transcriptional activation domain. It is a binding partner for E2F TRANSCRIPTION FACTORS and enhances the DNA binding and transactivation function of the DP-E2F complex.
Connective tissue cells which secrete an extracellular matrix rich in collagen and other macromolecules.
A specific pair of GROUP C CHROMOSOMES of the human chromosome classification.
The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.
A positive regulatory effect on physiological processes at the molecular, cellular, or systemic level. At the molecular level, the major regulatory sites include membrane receptors, genes (GENE EXPRESSION REGULATION), mRNAs (RNA, MESSENGER), and proteins.
A negative regulator of the CELL CYCLE that undergoes PHOSPHORYLATION by CYCLIN-DEPENDENT KINASES. It contains a conserved pocket region that binds E2F4 TRANSCRIPTION FACTOR and interacts with viral ONCOPROTEINS such as POLYOMAVIRUS TUMOR ANTIGENS; ADENOVIRUS E1A PROTEINS; and PAPILLOMAVIRUS E7 PROTEINS.
A subclass of dual specificity phosphatases that play a role in the progression of the CELL CYCLE. They dephosphorylate and activate CYCLIN-DEPENDENT KINASES.
Proteins whose abnormal expression (gain or loss) are associated with the development, growth, or progression of NEOPLASMS. Some neoplasm proteins are tumor antigens (ANTIGENS, NEOPLASM), i.e. they induce an immune reaction to their tumor. Many neoplasm proteins have been characterized and are used as tumor markers (BIOMARKERS, TUMOR) when they are detectable in cells and body fluids as monitors for the presence or growth of tumors. Abnormal expression of ONCOGENE PROTEINS is involved in neoplastic transformation, whereas the loss of expression of TUMOR SUPPRESSOR PROTEINS is involved with the loss of growth control and progression of the neoplasm.
A ubiquitously expressed regulatory protein that contains a retinoblastoma protein binding domain and an AT-rich interactive domain. The protein may play a role in recruiting HISTONE DEACETYLASES to the site of RETINOBLASTOMA PROTEIN-containing transcriptional repressor complexes.
A large multisubunit complex that plays an important role in the degradation of most of the cytosolic and nuclear proteins in eukaryotic cells. It contains a 700-kDa catalytic sub-complex and two 700-kDa regulatory sub-complexes. The complex digests ubiquitinated proteins and protein activated via ornithine decarboxylase antizyme.
A family of structurally-related proteins that were originally identified by their ability to complex with cyclin proteins (CYCLINS). They share a common domain that binds specifically to F-BOX MOTIFS. They take part in SKP CULLIN F-BOX PROTEIN LIGASES, where they can bind to a variety of F-BOX PROTEINS.
The first continuously cultured human malignant CELL LINE, derived from the cervical carcinoma of Henrietta Lacks. These cells are used for VIRUS CULTIVATION and antitumor drug screening assays.
Regulatory signaling systems that control the progression through the CELL CYCLE. They ensure that the cell has completed, in the correct order and without mistakes, all the processes required to replicate the GENOME and CYTOPLASM, and divide them equally between two daughter cells. If cells sense they have not completed these processes or that the environment does not have the nutrients and growth hormones in place to proceed, then the cells are restrained (or "arrested") until the processes are completed and growth conditions are suitable.
Molecular products metabolized and secreted by neoplastic tissue and characterized biochemically in cells or body fluids. They are indicators of tumor stage and grade as well as useful for monitoring responses to treatment and predicting recurrence. Many chemical groups are represented including hormones, antigens, amino and nucleic acids, enzymes, polyamines, and specific cell membrane proteins and lipids.
Laboratory mice that have been produced from a genetically manipulated EGG or EMBRYO, MAMMALIAN.
Diffusible gene products that act on homologous or heterologous molecules of viral or cellular DNA to regulate the expression of proteins.
Elements of limited time intervals, contributing to particular results or situations.
Recombinant proteins produced by the GENETIC TRANSLATION of fused genes formed by the combination of NUCLEIC ACID REGULATORY SEQUENCES of one or more genes with the protein coding sequences of one or more genes.
Immunologic method used for detecting or quantifying immunoreactive substances. The substance is identified by first immobilizing it by blotting onto a membrane and then tagging it with labeled antibodies.
A protein-serine-threonine kinase that is activated by PHOSPHORYLATION in response to GROWTH FACTORS or INSULIN. It plays a major role in cell metabolism, growth, and survival as a core component of SIGNAL TRANSDUCTION. Three isoforms have been described in mammalian cells.
Serologic tests in which a positive reaction manifested by visible CHEMICAL PRECIPITATION occurs when a soluble ANTIGEN reacts with its precipitins, i.e., ANTIBODIES that can form a precipitate.
Short sequences (generally about 10 base pairs) of DNA that are complementary to sequences of messenger RNA and allow reverse transcriptases to start copying the adjacent sequences of mRNA. Primers are used extensively in genetic and molecular biology techniques.
A family of enzymes that catalyze the conversion of ATP and a protein to ADP and a phosphoprotein.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
A gene silencing phenomenon whereby specific dsRNAs (RNA, DOUBLE-STRANDED) trigger the degradation of homologous mRNA (RNA, MESSENGER). The specific dsRNAs are processed into SMALL INTERFERING RNA (siRNA) which serves as a guide for cleavage of the homologous mRNA in the RNA-INDUCED SILENCING COMPLEX. DNA METHYLATION may also be triggered during this process.
Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.
Cells that line the inner and outer surfaces of the body by forming cellular layers (EPITHELIUM) or masses. Epithelial cells lining the SKIN; the MOUTH; the NOSE; and the ANAL CANAL derive from ectoderm; those lining the RESPIRATORY SYSTEM and the DIGESTIVE SYSTEM derive from endoderm; others (CARDIOVASCULAR SYSTEM and LYMPHATIC SYSTEM) derive from mesoderm. Epithelial cells can be classified mainly by cell shape and function into squamous, glandular and transitional epithelial cells.
Processes that stimulate the GENETIC TRANSCRIPTION of a gene or set of genes.
High molecular weight proteins found in the MICROTUBULES of the cytoskeletal system. Under certain conditions they are required for TUBULIN assembly into the microtubules and stabilize the assembled microtubules.
A specific pair of GROUP D CHROMOSOMES of the human chromosome classification.
MAMMARY GLANDS in the non-human MAMMALS.
Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.
An aspect of protein kinase (EC 2.7.1.37) in which serine residues in protamines and histones are phosphorylated in the presence of ATP.
Transport proteins that carry specific substances in the blood or across cell membranes.
A group of cell cycle proteins that negatively regulate the activity of CYCLIN/CYCLIN-DEPENDENT KINASE complexes. They inhibit CELL CYCLE progression and help control CELL PROLIFERATION following GENOTOXIC STRESS as well as during CELL DIFFERENTIATION.
An essential amino acid occurring naturally in the L-form, which is the active form. It is found in eggs, milk, gelatin, and other proteins.
A carcinoma derived from stratified SQUAMOUS EPITHELIAL CELLS. It may also occur in sites where glandular or columnar epithelium is normally present. (From Stedman, 25th ed)
Regulatory signaling systems that control the progression of the CELL CYCLE through the G1 PHASE and allow transition to S PHASE when the cells are ready to undergo DNA REPLICATION. DNA DAMAGE, or the deficiencies in specific cellular components or nutrients may cause the cells to halt before progressing through G1 phase.
Substances that inhibit or prevent the proliferation of NEOPLASMS.
Phosphotransferases that catalyzes the conversion of 1-phosphatidylinositol to 1-phosphatidylinositol 3-phosphate. Many members of this enzyme class are involved in RECEPTOR MEDIATED SIGNAL TRANSDUCTION and regulation of vesicular transport with the cell. Phosphatidylinositol 3-Kinases have been classified both according to their substrate specificity and their mode of action within the cell.
Protein kinase that drives both the mitotic and meiotic cycles in all eukaryotic organisms. In meiosis it induces immature oocytes to undergo meiotic maturation. In mitosis it has a role in the G2/M phase transition. Once activated by CYCLINS; MPF directly phosphorylates some of the proteins involved in nuclear envelope breakdown, chromosome condensation, spindle assembly, and the degradation of cyclins. The catalytic subunit of MPF is PROTEIN P34CDC2.
A superfamily of PROTEIN-SERINE-THREONINE KINASES that are activated by diverse stimuli via protein kinase cascades. They are the final components of the cascades, activated by phosphorylation by MITOGEN-ACTIVATED PROTEIN KINASE KINASES, which in turn are activated by mitogen-activated protein kinase kinase kinases (MAP KINASE KINASE KINASES).
Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.
Enzymes that oxidize certain LUMINESCENT AGENTS to emit light (PHYSICAL LUMINESCENCE). The luciferases from different organisms have evolved differently so have different structures and substrates.
A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).
Family of retrovirus-associated DNA sequences (myc) originally isolated from an avian myelocytomatosis virus. The proto-oncogene myc (c-myc) codes for a nuclear protein which is involved in nucleic acid metabolism and in mediating the cellular response to growth factors. Truncation of the first exon, which appears to regulate c-myc expression, is crucial for tumorigenicity. The human c-myc gene is located at 8q24 on the long arm of chromosome 8.
The aggregation of soluble ANTIGENS with ANTIBODIES, alone or with antibody binding factors such as ANTI-ANTIBODIES or STAPHYLOCOCCAL PROTEIN A, into complexes large enough to fall out of solution.
Mutant mice homozygous for the recessive gene "nude" which fail to develop a thymus. They are useful in tumor studies and studies on immune responses.
Processes required for CELL ENLARGEMENT and CELL PROLIFERATION.
Gated transport mechanisms by which proteins or RNA are moved across the NUCLEAR MEMBRANE.
A multifunctional CDC2 kinase-related kinase that plays roles in transcriptional elongation, CELL DIFFERENTIATION, and APOPTOSIS. It is found associated with CYCLIN T and is a component of POSITIVE TRANSCRIPTIONAL ELONGATION FACTOR B.
A nucleoside that substitutes for thymidine in DNA and thus acts as an antimetabolite. It causes breaks in chromosomes and has been proposed as an antiviral and antineoplastic agent. It has been given orphan drug status for use in the treatment of primary brain tumors.
A family of proteins that are structurally-related to Ubiquitin. Ubiquitins and ubiquitin-like proteins participate in diverse cellular functions, such as protein degradation and HEAT-SHOCK RESPONSE, by conjugation to other proteins.
The part of a cell that contains the CYTOSOL and small structures excluding the CELL NUCLEUS; MITOCHONDRIA; and large VACUOLES. (Glick, Glossary of Biochemistry and Molecular Biology, 1990)
Echinoderms having bodies of usually five radially disposed arms coalescing at the center.
A selective increase in the number of copies of a gene coding for a specific protein without a proportional increase in other genes. It occurs naturally via the excision of a copy of the repeating sequence from the chromosome and its extrachromosomal replication in a plasmid, or via the production of an RNA transcript of the entire repeating sequence of ribosomal RNA followed by the reverse transcription of the molecule to produce an additional copy of the original DNA sequence. Laboratory techniques have been introduced for inducing disproportional replication by unequal crossing over, uptake of DNA from lysed cells, or generation of extrachromosomal sequences from rolling circle replication.
The process by which a DNA molecule is duplicated.
An E2F transcription factor that represses GENETIC TRANSCRIPTION required for CELL CYCLE entry and DNA synthesis. E2F4 recruits chromatin remodeling factors indirectly to target gene PROMOTER REGIONS through RETINOBLASTOMA LIKE PROTEIN P130 and RETINOBLASTOMA LIKE PROTEIN P107.
Complexes of enzymes that catalyze the covalent attachment of UBIQUITIN to other proteins by forming a peptide bond between the C-terminal GLYCINE of UBIQUITIN and the alpha-amino groups of LYSINE residues in the protein. The complexes play an important role in mediating the selective-degradation of short-lived and abnormal proteins. The complex of enzymes can be broken down into three components that involve activation of ubiquitin (UBIQUITIN-ACTIVATING ENZYMES), conjugation of ubiquitin to the ligase complex (UBIQUITIN-CONJUGATING ENZYMES), and ligation of ubiquitin to the substrate protein (UBIQUITIN-PROTEIN LIGASES).
Detection of RNA that has been electrophoretically separated and immobilized by blotting on nitrocellulose or other type of paper or nylon membrane followed by hybridization with labeled NUCLEIC ACID PROBES.
A prediction of the probable outcome of a disease based on a individual's condition and the usual course of the disease as seen in similar situations.
A signal transducer and activator of transcription that mediates cellular responses to INTERLEUKIN-6 family members. STAT3 is constitutively activated in a variety of TUMORS and is a major downstream transducer for the CYTOKINE RECEPTOR GP130.

Transcriptional regulation of the cyclin D1 promoter by STAT5: its involvement in cytokine-dependent growth of hematopoietic cells. (1/369)

STAT5 is a member of a family of transcription factors that participate in the signal transduction pathways of many hormones and cytokines. Although STAT5 is suggested to play a crucial role in the biological effects of cytokines, its downstream target(s) associated with cell growth control is largely unknown. In a human interleukin-3 (IL-3)-dependent cell line F-36P-mpl, the induced expression of dominant-negative (dn)-STAT5 and of dn-ras led to inhibition of IL-3-dependent cell growth, accompanying the reduced expression of cyclin D1 mRNA. Also, both constitutively active forms of STAT5A (1*6-STAT5A) and ras (H-rasG12V) enabled F-36P-mpl cells to proliferate without added growth factors. In NIH 3T3 cells, 1*6-STAT5A and H-rasG12V individually and cooperatively transactivated the cyclin D1 promoter in luciferase assays. Both dn-STAT5 and dn-ras suppressed IL-3-induced cyclin D1 promoter activities in F-36P-mpl cells. Using a series of mutant cyclin D1 promoters, 1*6-STAT5A was found to transactivate the cyclin D1 promoter through the potential STAT-binding sequence at -481 bp. In electrophoretic mobility shift assays, STAT5 bound to the element in response to IL-3. Furthermore, the inhibitory effect of dn-STAT5 on IL-3-dependent growth was restored by expression of cyclin D1. Thus STAT5, in addition to ras signaling, appears to mediate transcriptional regulation of cyclin D1, thereby contributing to cytokine-dependent growth of hematopoietic cells.  (+info)

Cerebellar histogenesis is disturbed in mice lacking cyclin D2. (2/369)

Formation of brain requires deftly balancing primary genesis of neurons and glia, detection of when sufficient cells of each type have been produced, shutdown of proliferation and removal of excess cells. The region and cell type-specific expression of cell cycle regulatory proteins, such as demonstrated for cyclin D2, may contribute to these processes. If so, regional brain development should be affected by alteration of cyclin expression. To test this hypothesis, the representation of specific cell types was examined in the cerebellum of animals lacking cyclin D2. The loss of this cyclin primarily affected two neuronal populations: granule cell number was reduced and stellate interneurons were nearly absent. Differences between null and wild-type siblings were obvious by the second postnatal week. Decreases in granule cell number arose from both reduction in primary neurogenesis and increase in apoptosis of cells that fail to differentiate. The dearth of stellate cells in the molecular layer indicates that emergence of this subpopulation requires cyclin D2 expression. Surprisingly, Golgi and basket interneurons, thought to originate from the same precursor pool as stellate cells, appear unaffected. These results suggest that cyclin D2 is required in cerebellum not only for proliferation of the granule cell precursors but also for proper differentiation of granule and stellate interneurons.  (+info)

FLI-1 inhibits differentiation and induces proliferation of primary erythroblasts. (3/369)

Friend virus-induced erythroleukemia involves two members of the ETS family of transcriptional regulators, both activated via proviral insertion in the corresponding loci. Spi-1/PU.1 is expressed in the disease induced by the original Friend virus SFFV(F-MuLV) complex in adult mice. In contrast, FLI-1 is overexpressed in about 75% of the erythroleukemias induced by the F-MuLV helper virus in newborn mice. To analyse the consequences of the enforced expression of FLI-1 on erythroblast differentiation and proliferation and to compare its activity to that of PU.1/Spi-1, we used a heterologous system of avian primary erythroblasts previously described to study the cooperation between Spi-1/PU.1 and the other molecular alterations observed in SFFV-induced disease. FLI-1 was found: (i) to inhibit the apoptotic cell death program normally activated in erythroblasts following Epo deprivation; (ii) to inhibit the terminal differentiation program induced in these cells in response to Epo and; (iii) to induce their proliferation. However, in contrast to Spi-1/PU.1, the effects of FLI-1 on erythroblast, differentiation and proliferation did not require its cooperation with an abnormally activated form of the EpoR. Enhanced survival of FLI-1 expressing erythroblasts correlated with the upregulation of bcl2 expression. FLI-1 also prevented the rapid downregulation of cyclin D2 and D3 expression normally observed during Epo-induced differentiation and delayed the downregulation of several other genes involved in cell cycle or cell proliferation control. Our results show that overexpression of FLI-1 profoundly deregulates the normal balance between differentiation and proliferation in primary erythroblasts. Thus, the activation of FLI-1 expression observed at the onset of F-MuLV-induced erythroleukemia may provide a proliferative advantage to virus infected cells that would otherwise undergo terminal differentiation or cell death.  (+info)

The proto-oncogene c-myc is a direct target gene of Epstein-Barr virus nuclear antigen 2. (4/369)

Epstein-Barr virus (EBV) infects and transforms primary B lymphocytes in vitro. Viral infection initiates the cell cycle entry of the resting B lymphocytes. The maintenance of proliferation in the infected cells is strictly dependent on functional EBNA2. We have recently developed a conditional immortalization system for EBV by rendering the function of EBNA2, and thus proliferation of the immortalized cells, dependent on estrogen. This cellular system was used to identify early events preceding induction of proliferation. We show that LMP1 and c-myc are directly activated by EBNA2, indicating that all cellular factors essential for induction of these genes by EBNA2 are present in the resting cells. In contrast, induction of the cell cycle regulators cyclin D2 and cdk4 are secondary events, which require de novo protein synthesis.  (+info)

Control of cell cycle entry and apoptosis in B lymphocytes infected by Epstein-Barr virus. (5/369)

Infection of human B cells with Epstein-Barr virus (EBV) results in activation of the cell cycle and cell growth. To interpret the mechanisms by which EBV activates the cell, we have assayed many proteins involved in control of the G0 and G1 phases of the cell cycle and regulation of apoptosis. In EBV infection most of the changes, including the early induction of cyclin D2, are dependent on expression of EBV genes, but an alteration in the E2F-4 profile was partly independent of viral gene expression, presumably occurring in response to signal transduction activated when the virus binds to its receptor, CD21. By comparing the expression of genes controlling apoptosis, including those encoding several members of the BCL-2 family of proteins, the known relative resistance of EBV-immortalized B-cell lines to apoptosis induced by low serum was found to correlate with expression of both BCL-2 and A20. A20 can be regulated by the NF-kappaB transcription factor, which is known to be activated by the EBV LMP-1 protein. Quantitative assays demonstrated a direct temporal relationship between LMP-1 protein levels and active NF-kappaB during the time course of infection.  (+info)

Early induction of cyclin D2 expression in phorbol ester-responsive B-1 lymphocytes. (6/369)

B-1 lymphocytes represent a distinct B cell subset with characteristic features that include self-renewing capacity and unusual mitogenic responses. B-1 cells differ from conventional B cells in terms of the consequences of phorbol ester treatment: B-1 cells rapidly enter S phase in response to phorbol ester alone, whereas B-2 cells require a calcium ionophore in addition to phorbol ester to trigger cell cycle progression. To address the mechanism underlying the varied proliferative responses of B-1 and B-2 cells, we evaluated the expression and activity of the G1 cell cycle regulator, cyclin D2, and its associated cyclin-dependent kinases (Cdks). Cyclin D2 expression was upregulated rapidly, within 2-4 h, in phorbol ester-stimulated B-1 cells, in a manner dependent on intact transcription/translation, but was not increased in phorbol ester- stimulated B-2 cells. Phorbol ester-stimulated cyclin D2 expression was accompanied by the formation of cyclin D2-Cdk4, and, to a lesser extent, cyclin D2-Cdk6, complexes; cyclin D2- containing complexes were found to be catalytically functional, in terms of their ability to phosphorylate exogenous Rb in vitro and to specifically phosphorylate endogenous Rb on serine780 in vivo. These results strongly suggest that the rapid induction of cyclin D2 by a normally nonmitogenic phorbol ester stimulus is responsible for B-1 cell progression through G1 phase. The ease and rapidity with which cyclin D2 responds in B-1 cells may contribute to the proliferative features of this subset.  (+info)

Involvement of p21(WAF1/Cip1) and p27(Kip1) in intestinal epithelial cell differentiation. (7/369)

Using the conditionally immortalized human cell line tsFHI, we have investigated the role of cyclin-dependent kinase inhibitors (CKIs) in intestinal epithelial cell differentiation. Expression of cyclins, cyclin-dependent kinases (Cdk), and CKIs was examined under conditions promoting growth, growth arrest, or expression of differentiated traits. Formation of complexes among cell cycle regulatory proteins and their kinase activities were also investigated. The tsFHI cells express three CKIs: p16, p21, and p27. With differentiation, p21 and p27 were strongly induced, but with different kinetics: the p21 increase was rapid but transient and the p27 increase was delayed but sustained. Our results suggest that the function of p16 is primarily to inhibit cyclin D-associated kinases, making tsFHI cells dependent on cyclin E-Cdk2 for pRb phosphorylation and G1/S progression. Furthermore, they indicate that p21 is the main CKI involved in irreversible growth arrest during the early stages of cell differentiation in association with D-type cyclins, cyclin E, and Cdk2, whereas p27 may induce or stabilize expression of differentiated traits acting independently of cyclin-Cdk function.  (+info)

Molecular analysis of selected cell cycle regulatory proteins during aerobic and hypoxic maintenance of human ovarian carcinoma cells. (8/369)

We have previously reported on the development of an in vitro model system for studying the effect of hypoxia on ovarian carcinoma cell proliferation and invasion (Krtolica and Ludlow, 1996). These data indicate that the cell division cycle is reversibly arrested during the G1 phase. Here, we have continued this study to include the proliferation properties of both aerobic and hypoxic human ovarian carcinoma cells at the molecular level. The growth suppressor product of the retinoblastoma susceptibility gene, pRB, appears to be functional in these cells as determined by SV40 T-antigen binding studies. Additional G1-to-S cell cycle regulatory proteins, cyclins D and E, cyclin-dependent kinases (cdks) 4 and 2, and cdk inhibitors p27 and p18, also appear to be intact based on their apparent molecular weights and cell cycle stage-specific abundance. During hypoxia, there is a decrease in abundance of cyclins D and E, with an increase in p27 abundance. cdk4 activity towards pRB and cdk2 activity towards histone H1 are also decreased. Co-precipitation studies revealed an increased amount of p27 complexing with cyclin E-cdk2 during hypoxia than during aerobic cell growth. In addition, pRB-directed phosphatase activity was found to be greater in hypoxic than aerobic cells. Taken together, a model is suggested to explain hypoxia-induced cell cycle arrest in SKA human ovarian carcinoma cells.  (+info)

Cyclin D1 is a type of cyclin protein that plays a crucial role in the regulation of the cell cycle, which is the process by which cells divide and grow. Specifically, Cyclin D1 is involved in the transition from the G1 phase to the S phase of the cell cycle. It does this by forming a complex with and acting as a regulatory subunit of cyclin-dependent kinase 4 (CDK4) or CDK6, which phosphorylates and inactivates the retinoblastoma protein (pRb). This allows the E2F transcription factors to be released and activate the transcription of genes required for DNA replication and cell cycle progression.

Overexpression of Cyclin D1 has been implicated in the development of various types of cancer, as it can lead to uncontrolled cell growth and division. Therefore, Cyclin D1 is an important target for cancer therapy, and inhibitors of CDK4/6 have been developed to treat certain types of cancer that overexpress Cyclin D1.

Cyclin D2 is a type of cyclin protein that regulates the cell cycle, particularly in the G1 phase. It forms a complex with and acts as a regulatory subunit of cyclin-dependent kinase 4 (CDK4) or CDK6, promoting the transition from G1 to S phase of the cell cycle. The expression of cyclin D2 is regulated by various growth factors, hormones, and oncogenes, and its dysregulation has been implicated in the development of several types of cancer.

Cyclin D3 is a type of cyclin protein that regulates the cell cycle, particularly during the G1 phase. It forms a complex with and acts as a regulatory subunit of CDK4 or CDK6, which are cyclin-dependent kinases. This complex plays a crucial role in phosphorylating and inactivating the retinoblastoma protein (pRb), leading to the release of E2F transcription factors that promote the expression of genes required for DNA replication and cell cycle progression into the S phase.

Cyclin D3 is primarily expressed in activated lymphocytes and is essential for normal immune function, as well as in certain tissues during development. Alterations in CYCLIN D3 gene expression or function have been implicated in several types of cancer, such as leukemias and lymphomas, due to their role in uncontrolled cell proliferation.

Cyclin A is a type of cyclin protein that regulates the progression of the cell cycle, particularly through the G1 and S phases. It forms a complex with and acts as a regulatory subunit for cyclin-dependent kinases (CDKs), specifically CDK2 and CDK1. The activation of Cyclin A-CDK complexes leads to phosphorylation of various target proteins, which in turn regulates DNA replication and the transition to mitosis.

Cyclin A levels rise during the late G1 phase and peak during the S phase, after which they decline rapidly during the G2 phase. Any abnormalities in Cyclin A regulation or expression can contribute to uncontrolled cell growth and cancer development.

Cyclin D is a type of cyclin protein that plays a crucial role in the regulation of the cell cycle, which is the process by which cells grow and divide. Specifically, Cyclin D is involved in the G1 phase of the cell cycle and works in conjunction with its partner enzyme, cyclin-dependent kinase 4 (CDK4) or CDK6, to phosphorylate and regulate the activity of several key proteins that control the transition from G1 to S phase.

There are several different types of Cyclin D proteins, including Cyclin D1, Cyclin D2, and Cyclin D3, which are encoded by different genes but share similar structures and functions. Overexpression or dysregulation of Cyclin D has been implicated in the development of various human cancers, as it can lead to uncontrolled cell growth and division. Therefore, understanding the role of Cyclin D in the cell cycle and its regulation is important for developing potential cancer therapies.

Cyclin E is a type of cyclin protein that plays a crucial role in the regulation of the cell cycle, particularly during the G1 phase and the transition to the S phase. It functions as a regulatory subunit of the Cyclin-dependent kinase 2 (CDK2) complex, which is responsible for promoting the progression of the cell cycle.

Cyclin E is synthesized during the late G1 phase of the cell cycle and accumulates to high levels until it forms a complex with CDK2. The Cyclin E-CDK2 complex then phosphorylates several target proteins, leading to the activation of various downstream pathways that promote DNA replication and cell cycle progression.

The regulation of Cyclin E expression and activity is tightly controlled through multiple mechanisms, including transcriptional regulation, protein stability, and proteasomal degradation. Dysregulation of Cyclin E has been implicated in various human cancers, including breast, ovarian, and lung cancer, due to its role in promoting uncontrolled cell proliferation and genomic instability.

Cyclin B is a type of cyclin protein that regulates the cell cycle, specifically the transition from G2 phase to mitosis (M phase) in eukaryotic cells. Cyclin B binds and activates cyclin-dependent kinase 1 (CDK1), forming the complex known as M-phase promoting factor (MPF). This complex triggers the events leading to cell division, such as chromosome condensation, nuclear envelope breakdown, and spindle formation. The levels of cyclin B increase during the G2 phase and are degraded by the anaphase-promoting complex/cyclosome (APC/C) at the onset of anaphase, allowing the cell cycle to progress into the next phase.

Cyclin B1 is a type of cyclin protein that regulates the cell cycle, specifically the transition from G2 phase to mitosis (M phase) in eukaryotic cells. It forms a complex with and acts as a regulatory subunit of cyclin-dependent kinase 1 (CDK1), also known as CDC2. During the G2 phase, Cyclin B1 levels accumulate and upon reaching a certain threshold, it binds to CDK1 to form the maturation promoting factor (MPF). The activation of MPF triggers the onset of mitosis by promoting nuclear envelope breakdown, chromosome condensation, and other events required for cell division. After the completion of mitosis, Cyclin B1 is degraded by the ubiquitin-proteasome system, allowing the cell cycle to progress back into G1 phase.

Cyclin A1 is a type of cyclin protein that regulates the cell cycle, particularly during the S and G2 phases. It forms a complex with and acts as a regulatory subunit of cyclin-dependent kinase 2 (CDK2), helping to control the transition from the G1 phase to the S phase and from the S phase to the G2 phase. Cyclin A1 is expressed in various tissues, including ovary, testis, bone marrow, and lymphoid cells. Overexpression or dysregulation of cyclin A1 has been implicated in several types of cancer, making it a potential target for cancer therapy.

Cyclins are a family of regulatory proteins that play a crucial role in the cell cycle, which is the series of events that take place as a cell grows, divides, and produces two daughter cells. They are called cyclins because their levels fluctuate or cycle during the different stages of the cell cycle.

Cyclins function as subunits of serine/threonine protein kinase complexes, forming an active enzyme that adds phosphate groups to other proteins, thereby modifying their activity. This post-translational modification is a critical mechanism for controlling various cellular processes, including the regulation of the cell cycle.

There are several types of cyclins (A, B, D, and E), each of which is active during specific phases of the cell cycle:

1. Cyclin D: Expressed in the G1 phase, it helps to initiate the cell cycle by activating cyclin-dependent kinases (CDKs) that promote progression through the G1 restriction point.
2. Cyclin E: Active during late G1 and early S phases, it forms a complex with CDK2 to regulate the transition from G1 to S phase, where DNA replication occurs.
3. Cyclin A: Expressed in the S and G2 phases, it associates with both CDK2 and CDK1 to control the progression through the S and G2 phases and entry into mitosis (M phase).
4. Cyclin B: Active during late G2 and M phases, it partners with CDK1 to regulate the onset of mitosis by controlling the breakdown of the nuclear envelope, chromosome condensation, and spindle formation.

The activity of cyclins is tightly controlled through several mechanisms, including transcriptional regulation, protein degradation, and phosphorylation/dephosphorylation events. Dysregulation of cyclin expression or function can lead to uncontrolled cell growth and proliferation, which are hallmarks of cancer.

Cyclin A2 is a type of cyclin protein that regulates the cell cycle, which is the series of events that cells undergo as they grow and divide. Specifically, Cyclin A2 plays a role in the progression from the G1 phase to the S phase (DNA synthesis phase) and from the G2 phase to the M phase (mitosis phase) of the cell cycle. It does this by binding to and activating cyclin-dependent kinases (CDKs), which are enzymes that help regulate the cell cycle.

Cyclin A2 is expressed at various points during the cell cycle, but its levels peak during the S and G2 phases. The protein is degraded during mitosis, ensuring that it is not present in excess during the next cell cycle. Dysregulation of Cyclin A2 has been implicated in the development of cancer, as uncontrolled cell growth and division are hallmarks of this disease.

Cyclin-Dependent Kinase 4 (CDK4) is a type of enzyme, specifically a serine/threonine protein kinase, that plays a crucial role in the regulation of the cell cycle. The cell cycle is the series of events that take place in a cell leading to its division and duplication. CDK4, when activated by binding to cyclin D, helps to promote the transition from the G1 phase to the S phase of the cell cycle. This transition is a critical point in the regulation of cell growth and division, and dysregulation of this process can lead to uncontrolled cell growth and cancer. CDK4 inhibitors are used in the treatment of certain types of cancer, such as breast and lung cancer, to block the activity of CDK4 and prevent tumor cell proliferation.

Cyclin-dependent kinases (CDKs) are a family of serine/threonine protein kinases that play crucial roles in regulating the cell cycle, transcription, and other cellular processes. They are activated by binding to cyclin proteins, which accumulate and degrade at specific stages of the cell cycle. The activation of CDKs leads to phosphorylation of various downstream target proteins, resulting in the promotion or inhibition of different cell cycle events. Dysregulation of CDKs has been implicated in several human diseases, including cancer, and they are considered important targets for drug development.

Cyclin G1 is a type of protein that belongs to the cyclin family, which are involved in the regulation of the cell cycle. The cell cycle is the series of events that take place as a cell grows, copies its DNA, and divides into two daughter cells.

Cyclin G1 regulates the cell cycle by interacting with various cyclin-dependent kinases (CDKs), which are enzymes that help control the progression of the cell cycle. Specifically, Cyclin G1 has been shown to inhibit the activity of CDK1 and CDK2, which play important roles in regulating the transition from the G1 phase to the S phase of the cell cycle.

Cyclin G1 has also been implicated in other cellular processes, including DNA damage repair, apoptosis (programmed cell death), and tumor suppression. Dysregulation of Cyclin G1 has been linked to various types of cancer, making it a potential target for cancer therapy.

Cyclin G is a type of protein that belongs to the cyclin family, which are involved in the regulation of the cell cycle. The human Cyclin G gene encodes two isoforms, Cyclin G1 and Cyclin G2, which share a similar structure but have different functions.

Cyclin G1 is known to play a role in the negative regulation of the cell cycle, particularly during the G1 phase. It interacts with several proteins, including CDKs (cyclin-dependent kinases), to regulate the activity of various transcription factors and other signaling pathways that control cell growth and division.

Cyclin G2, on the other hand, has been implicated in the regulation of DNA damage response and apoptosis (programmed cell death). It interacts with CDKs and other proteins to modulate the activity of various signaling pathways involved in these processes.

Overall, Cyclin G plays important roles in regulating cell cycle progression, DNA damage response, and apoptosis, and its dysregulation has been linked to several human diseases, including cancer.

The cell cycle is a series of events that take place in a cell leading to its division and duplication. It consists of four main phases: G1 phase, S phase, G2 phase, and M phase.

During the G1 phase, the cell grows in size and synthesizes mRNA and proteins in preparation for DNA replication. In the S phase, the cell's DNA is copied, resulting in two complete sets of chromosomes. During the G2 phase, the cell continues to grow and produces more proteins and organelles necessary for cell division.

The M phase is the final stage of the cell cycle and consists of mitosis (nuclear division) and cytokinesis (cytoplasmic division). Mitosis results in two genetically identical daughter nuclei, while cytokinesis divides the cytoplasm and creates two separate daughter cells.

The cell cycle is regulated by various checkpoints that ensure the proper completion of each phase before progressing to the next. These checkpoints help prevent errors in DNA replication and division, which can lead to mutations and cancer.

Cyclin-Dependent Kinase 2 (CDK2) is a type of enzyme that plays a crucial role in the regulation of the cell cycle, which is the process by which cells grow and divide. CDK2 is activated when it binds to a regulatory subunit called a cyclin.

During the cell cycle, CDK2 helps to control the progression from the G1 phase to the S phase, where DNA replication occurs. Specifically, CDK2 phosphorylates various target proteins that are involved in the regulation of DNA replication and the initiation of mitosis, which is the process of cell division.

CDK2 activity is tightly regulated through a variety of mechanisms, including phosphorylation, dephosphorylation, and protein degradation. Dysregulation of CDK2 activity has been implicated in various human diseases, including cancer. Therefore, CDK2 is an important target for the development of therapies aimed at treating these diseases.

The G1 phase, or Gap 1 phase, is the first phase of the cell cycle, during which the cell grows in size and synthesizes mRNA and proteins in preparation for subsequent steps leading to mitosis. During this phase, the cell also checks its growth and makes sure that it is large enough to proceed through the cell cycle. If the cell is not large enough, it will arrest in the G1 phase until it has grown sufficiently. The G1 phase is followed by the S phase, during which DNA replication occurs.

BCL-1 (B-cell leukemia/lymphoma 1) is not a gene itself but rather a chromosomal translocation that results in the formation of an abnormal fusion gene. The BCL-1 translocation, also known as t(14;18)(q32;q21), is most commonly found in follicular lymphoma, a type of slow-growing non-Hodgkin lymphoma.

The BCL-1 translocation involves the juxtaposition of the BCL-2 gene, which is located on chromosome 18, with the IGH (immunoglobulin heavy chain) gene, which is located on chromosome 14. This translocation results in the overexpression of the BCL-2 protein, which inhibits apoptosis or programmed cell death. The overexpression of BCL-2 leads to the accumulation of cancer cells and contributes to the development and progression of follicular lymphoma.

It is important to note that while BCL-1 is a chromosomal translocation, it can also refer to the protein encoded by the BCL-2 gene when it is overexpressed due to the t(14;18) translocation. In this context, BCL-1 is considered a proto-oncogene because its overexpression promotes cancer development and progression.

Cyclin C is a type of cyclin protein that plays a crucial role in the regulation of the cell cycle, which is the process by which cells grow and divide. Specifically, Cyclin C is involved in the transition from the G1 phase to the S phase of the cell cycle, during which DNA replication occurs.

Cyclin C forms a complex with cyclin-dependent kinase 8 (CDK8) and other regulatory subunits to form the CDK8 module, which is part of the mediator complex that regulates gene transcription. The activity of Cyclin C/CDK8 is regulated by various mechanisms, including phosphorylation and degradation, to ensure proper control of the cell cycle and prevent uncontrolled cell growth and division.

Mutations in the gene encoding Cyclin C have been associated with certain types of cancer, highlighting its importance in maintaining genomic stability and preventing tumorigenesis.

Retinoblastoma Protein (pRb or RB1) is a tumor suppressor protein that plays a critical role in regulating the cell cycle and preventing uncontrolled cell growth. It is encoded by the RB1 gene, located on chromosome 13. The retinoblastoma protein functions as a regulatory checkpoint in the cell cycle, preventing cells from progressing into the S phase (DNA synthesis phase) until certain conditions are met.

When pRb is in its active state, it binds to and inhibits the activity of E2F transcription factors, which promote the expression of genes required for DNA replication and cell cycle progression. Phosphorylation of pRb by cyclin-dependent kinases (CDKs) leads to the release of E2F factors, allowing them to activate their target genes and drive the cell into S phase.

Mutations in the RB1 gene can result in the production of a nonfunctional or reduced amount of pRb protein, leading to uncontrolled cell growth and an increased risk of developing retinoblastoma, a rare form of eye cancer, as well as other types of tumors.

CDC2 and CDC28 are members of the Serine/Threonine protein kinase family, which play crucial roles in the regulation of the cell cycle. These kinases were originally identified in yeast (CDC28) and humans (CDC2), but they are highly conserved across eukaryotes.

CDC2-CDC28 Kinases function as a part of larger complexes, often associated with cyclins, to control different phases of the cell cycle by phosphorylating specific substrates at key regulatory points. The activity of CDC2-CDC28 Kinases is tightly regulated through various mechanisms, including phosphorylation, dephosphorylation, and protein binding interactions.

During the G2 phase of the cell cycle, CDC2-CDC28 Kinases are inactivated by phosphorylation at specific residues (Tyr15 and Thr14). As the cell approaches mitosis, a family of phosphatases called Cdc25 removes these inhibitory phosphates, leading to activation of the kinase. Activated CDC2-CDC28 Kinases then initiate mitotic processes such as chromosome condensation and nuclear envelope breakdown.

In summary, CDC2-CDC28 Kinases are essential regulators of the eukaryotic cell cycle, controlling various aspects of cell division through phosphorylation of specific substrates. Their activity is tightly regulated to ensure proper progression through the cell cycle and prevent uncontrolled cell growth, which can lead to diseases such as cancer.

Cyclin B2 is a type of cyclin protein that regulates the cell cycle, particularly at the G2 phase and the beginning of mitosis. It forms a complex with and acts as a regulatory subunit of cyclin-dependent kinase 1 (CDK1), which plays a crucial role in the transition from G2 phase to mitosis. The expression and activity of Cyclin B2 are tightly regulated during the cell cycle, and its dysregulation can lead to abnormal cell division and contribute to the development of cancer.

Cyclin T is a type of cyclin protein that is encoded by the CCNT2 gene in humans. Cyclins are a family of regulatory proteins that play a crucial role in the cell cycle, which is the series of events that cells undergo as they grow and divide. Specifically, cyclin T is a component of the CDK9/cyclin T complex, also known as positive transcription elongation factor b (P-TEFb), which plays a key role in regulating gene expression by controlling the elongation phase of RNA polymerase II-mediated transcription.

Cyclin T is expressed at various stages of the cell cycle and has been shown to interact with several other proteins involved in cell cycle regulation, including the retinoblastoma protein (pRb) and the E2F family of transcription factors. Dysregulation of cyclin T expression or activity has been implicated in several human diseases, including cancer.

Oncogene proteins are derived from oncogenes, which are genes that have the potential to cause cancer. Normally, these genes help regulate cell growth and division, but when they become altered or mutated, they can become overactive and lead to uncontrolled cell growth and division, which is a hallmark of cancer. Oncogene proteins can contribute to tumor formation and progression by promoting processes such as cell proliferation, survival, angiogenesis, and metastasis. Examples of oncogene proteins include HER2/neu, EGFR, and BCR-ABL.

Cyclin H is a type of protein that is classified as a cyclin, which is a regulatory subunit of cyclin-dependent kinases (CDKs). Specifically, Cyclin H forms a complex with CDK7 and functions as an essential component of the cell cycle transcriptional coactivator known as TFIIH.

TFIIH plays a crucial role in the initiation of transcription by RNA polymerase II and also participates in the process of DNA repair. The Cyclin H-CDK7 complex phosphorylates the carboxy-terminal domain (CTD) of the largest subunit of RNA polymerase II, which is a critical step in the transcription cycle. Additionally, Cyclin H-CDK7 also plays a role in regulating the cell cycle by controlling the activity of certain cell cycle regulators, such as E2F transcription factors.

Mutations in the gene that encodes Cyclin H have been associated with certain human diseases, including a rare inherited disorder called Cockayne syndrome, which is characterized by developmental abnormalities, neurological dysfunction, and premature aging.

Cell cycle proteins are a group of regulatory proteins that control the progression of the cell cycle, which is the series of events that take place in a eukaryotic cell leading to its division and duplication. These proteins can be classified into several categories based on their functions during different stages of the cell cycle.

The major groups of cell cycle proteins include:

1. Cyclin-dependent kinases (CDKs): CDKs are serine/threonine protein kinases that regulate key transitions in the cell cycle. They require binding to a regulatory subunit called cyclin to become active. Different CDK-cyclin complexes are activated at different stages of the cell cycle.
2. Cyclins: Cyclins are a family of regulatory proteins that bind and activate CDKs. Their levels fluctuate throughout the cell cycle, with specific cyclins expressed during particular phases. For example, cyclin D is important for the G1 to S phase transition, while cyclin B is required for the G2 to M phase transition.
3. CDK inhibitors (CKIs): CKIs are regulatory proteins that bind to and inhibit CDKs, thereby preventing their activation. CKIs can be divided into two main families: the INK4 family and the Cip/Kip family. INK4 family members specifically inhibit CDK4 and CDK6, while Cip/Kip family members inhibit a broader range of CDKs.
4. Anaphase-promoting complex/cyclosome (APC/C): APC/C is an E3 ubiquitin ligase that targets specific proteins for degradation by the 26S proteasome. During the cell cycle, APC/C regulates the metaphase to anaphase transition and the exit from mitosis by targeting securin and cyclin B for degradation.
5. Other regulatory proteins: Several other proteins play crucial roles in regulating the cell cycle, such as p53, a transcription factor that responds to DNA damage and arrests the cell cycle, and the polo-like kinases (PLKs), which are involved in various aspects of mitosis.

Overall, cell cycle proteins work together to ensure the proper progression of the cell cycle, maintain genomic stability, and prevent uncontrolled cell growth, which can lead to cancer.

In the context of cell biology, "S phase" refers to the part of the cell cycle during which DNA replication occurs. The "S" stands for synthesis, reflecting the active DNA synthesis that takes place during this phase. It is preceded by G1 phase (gap 1) and followed by G2 phase (gap 2), with mitosis (M phase) being the final stage of the cell cycle.

During S phase, the cell's DNA content effectively doubles as each chromosome is replicated to ensure that the two resulting daughter cells will have the same genetic material as the parent cell. This process is carefully regulated and coordinated with other events in the cell cycle to maintain genomic stability.

Cyclin G2 is a type of protein that belongs to the cyclin family, which are involved in the regulation of the cell cycle. The cell cycle is the series of events that cells undergo as they grow and divide. Specifically, Cyclin G2 regulates the G1 phase of the cell cycle, which is the phase where the cell prepares to divide.

Cyclin G2 has been found to play a role in several important cellular processes, including DNA damage response, apoptosis (programmed cell death), and differentiation. It has also been implicated in the development of certain diseases, such as cancer. For example, Cyclin G2 has been shown to have tumor-suppressive functions, and its expression is often reduced in cancer cells.

In summary, Cyclin G2 is a regulatory protein that plays a critical role in controlling the cell cycle and maintaining genomic stability. Its dysregulation has been associated with various diseases, including cancer.

CDC2 protein kinase, also known as cell division cycle 2 or CDK1, is a type of enzyme that plays a crucial role in the regulation of the cell cycle. The cell cycle is the series of events that cells undergo as they grow, replicate their DNA, and divide into two daughter cells.

CDC2 protein kinase is a member of the cyclin-dependent kinase (CDK) family, which are serine/threonine protein kinases that are activated by binding to regulatory subunits called cyclins. CDC2 protein kinase is primarily associated with the regulation of the G2 phase and the entry into mitosis, the stage of the cell cycle where nuclear and cytoplasmic division occur.

CDC2 protein kinase functions by phosphorylating various target proteins, which alters their activity and contributes to the coordination of the different events that occur during the cell cycle. The activity of CDC2 protein kinase is tightly regulated through a variety of mechanisms, including phosphorylation and dephosphorylation, as well as the binding and destruction of cyclin subunits.

Dysregulation of CDC2 protein kinase has been implicated in various human diseases, including cancer, where uncontrolled cell division can lead to the formation of tumors. Therefore, understanding the regulation and function of CDC2 protein kinase is an important area of research in molecular biology and medicine.

Cell proliferation is the process by which cells increase in number, typically through the process of cell division. In the context of biology and medicine, it refers to the reproduction of cells that makes up living tissue, allowing growth, maintenance, and repair. It involves several stages including the transition from a phase of quiescence (G0 phase) to an active phase (G1 phase), DNA replication in the S phase, and mitosis or M phase, where the cell divides into two daughter cells.

Abnormal or uncontrolled cell proliferation is a characteristic feature of many diseases, including cancer, where deregulated cell cycle control leads to excessive and unregulated growth of cells, forming tumors that can invade surrounding tissues and metastasize to distant sites in the body.

Cyclin-dependent kinase inhibitor p21, also known as CDKN1A or p21/WAF1/CIP1, is a protein that regulates the cell cycle. It inhibits the activity of cyclin-dependent kinases (CDKs), which are enzymes that play crucial roles in controlling the progression of the cell cycle.

The binding of p21 to CDKs prevents the phosphorylation and activation of downstream targets, leading to cell cycle arrest. This protein is transcriptionally activated by tumor suppressor protein p53 in response to DNA damage or other stress signals, and it functions as an important mediator of p53-dependent growth arrest.

By inhibiting CDKs, p21 helps to ensure that cells do not proceed through the cell cycle until damaged DNA has been repaired, thereby preventing the propagation of potentially harmful mutations. Additionally, p21 has been implicated in other cellular processes such as apoptosis, differentiation, and senescence. Dysregulation of p21 has been associated with various human diseases, including cancer.

Phosphorylation is the process of adding a phosphate group (a molecule consisting of one phosphorus atom and four oxygen atoms) to a protein or other organic molecule, which is usually done by enzymes called kinases. This post-translational modification can change the function, localization, or activity of the target molecule, playing a crucial role in various cellular processes such as signal transduction, metabolism, and regulation of gene expression. Phosphorylation is reversible, and the removal of the phosphate group is facilitated by enzymes called phosphatases.

Cell division is the process by which a single eukaryotic cell (a cell with a true nucleus) divides into two identical daughter cells. This complex process involves several stages, including replication of DNA, separation of chromosomes, and division of the cytoplasm. There are two main types of cell division: mitosis and meiosis.

Mitosis is the type of cell division that results in two genetically identical daughter cells. It is a fundamental process for growth, development, and tissue repair in multicellular organisms. The stages of mitosis include prophase, prometaphase, metaphase, anaphase, and telophase, followed by cytokinesis, which divides the cytoplasm.

Meiosis, on the other hand, is a type of cell division that occurs in the gonads (ovaries and testes) during the production of gametes (sex cells). Meiosis results in four genetically unique daughter cells, each with half the number of chromosomes as the parent cell. This process is essential for sexual reproduction and genetic diversity. The stages of meiosis include meiosis I and meiosis II, which are further divided into prophase, prometaphase, metaphase, anaphase, and telophase.

In summary, cell division is the process by which a single cell divides into two daughter cells, either through mitosis or meiosis. This process is critical for growth, development, tissue repair, and sexual reproduction in multicellular organisms.

Protein-Serine-Threonine Kinases (PSTKs) are a type of protein kinase that catalyzes the transfer of a phosphate group from ATP to the hydroxyl side chains of serine or threonine residues on target proteins. This phosphorylation process plays a crucial role in various cellular signaling pathways, including regulation of metabolism, gene expression, cell cycle progression, and apoptosis. PSTKs are involved in many physiological and pathological processes, and their dysregulation has been implicated in several diseases, such as cancer, diabetes, and neurodegenerative disorders.

A cell line that is derived from tumor cells and has been adapted to grow in culture. These cell lines are often used in research to study the characteristics of cancer cells, including their growth patterns, genetic changes, and responses to various treatments. They can be established from many different types of tumors, such as carcinomas, sarcomas, and leukemias. Once established, these cell lines can be grown and maintained indefinitely in the laboratory, allowing researchers to conduct experiments and studies that would not be feasible using primary tumor cells. It is important to note that tumor cell lines may not always accurately represent the behavior of the original tumor, as they can undergo genetic changes during their time in culture.

Cyclin-Dependent Kinase Inhibitor p27, also known as CDKN1B or p27Kip1, is a protein that regulates the cell cycle. It inhibits the activity of certain cyclin-dependent kinases (CDKs), which are enzymes that play key roles in regulating the progression of the cell cycle.

The cell cycle is a series of events that cells undergo as they grow and divide. Cyclins and CDKs help to control the different stages of the cell cycle by activating and deactivating various proteins at specific times. The p27 protein acts as a brake on the cell cycle, preventing cells from dividing too quickly or abnormally.

When p27 binds to a CDK-cyclin complex, it prevents the complex from phosphorylating its target proteins, which are necessary for the progression of the cell cycle. By inhibiting CDK activity, p27 helps to ensure that cells divide only when the proper conditions are met.

Mutations in the CDKN1B gene, which encodes p27, have been associated with several types of cancer, including breast, lung, and prostate cancer. These mutations can lead to decreased levels of p27 or impaired function, allowing cells to divide uncontrollably and form tumors.

Proto-oncogene proteins are normal cellular proteins that play crucial roles in various cellular processes, such as signal transduction, cell cycle regulation, and apoptosis (programmed cell death). They are involved in the regulation of cell growth, differentiation, and survival under physiological conditions.

When proto-oncogene proteins undergo mutations or aberrations in their expression levels, they can transform into oncogenic forms, leading to uncontrolled cell growth and division. These altered proteins are then referred to as oncogene products or oncoproteins. Oncogenic mutations can occur due to various factors, including genetic predisposition, environmental exposures, and aging.

Examples of proto-oncogene proteins include:

1. Ras proteins: Involved in signal transduction pathways that regulate cell growth and differentiation. Activating mutations in Ras genes are found in various human cancers.
2. Myc proteins: Regulate gene expression related to cell cycle progression, apoptosis, and metabolism. Overexpression of Myc proteins is associated with several types of cancer.
3. EGFR (Epidermal Growth Factor Receptor): A transmembrane receptor tyrosine kinase that regulates cell proliferation, survival, and differentiation. Mutations or overexpression of EGFR are linked to various malignancies, such as lung cancer and glioblastoma.
4. Src family kinases: Intracellular tyrosine kinases that regulate signal transduction pathways involved in cell proliferation, survival, and migration. Dysregulation of Src family kinases is implicated in several types of cancer.
5. Abl kinases: Cytoplasmic tyrosine kinases that regulate various cellular processes, including cell growth, differentiation, and stress responses. Aberrant activation of Abl kinases, as seen in chronic myelogenous leukemia (CML), leads to uncontrolled cell proliferation.

Understanding the roles of proto-oncogene proteins and their dysregulation in cancer development is essential for developing targeted cancer therapies that aim to inhibit or modulate these aberrant signaling pathways.

Neoplastic gene expression regulation refers to the processes that control the production of proteins and other molecules from genes in neoplastic cells, or cells that are part of a tumor or cancer. In a normal cell, gene expression is tightly regulated to ensure that the right genes are turned on or off at the right time. However, in cancer cells, this regulation can be disrupted, leading to the overexpression or underexpression of certain genes.

Neoplastic gene expression regulation can be affected by a variety of factors, including genetic mutations, epigenetic changes, and signals from the tumor microenvironment. These changes can lead to the activation of oncogenes (genes that promote cancer growth and development) or the inactivation of tumor suppressor genes (genes that prevent cancer).

Understanding neoplastic gene expression regulation is important for developing new therapies for cancer, as targeting specific genes or pathways involved in this process can help to inhibit cancer growth and progression.

Tumor suppressor proteins are a type of regulatory protein that helps control the cell cycle and prevent cells from dividing and growing in an uncontrolled manner. They work to inhibit tumor growth by preventing the formation of tumors or slowing down their progression. These proteins can repair damaged DNA, regulate gene expression, and initiate programmed cell death (apoptosis) if the damage is too severe for repair.

Mutations in tumor suppressor genes, which provide the code for these proteins, can lead to a decrease or loss of function in the resulting protein. This can result in uncontrolled cell growth and division, leading to the formation of tumors and cancer. Examples of tumor suppressor proteins include p53, Rb (retinoblastoma), and BRCA1/2.

I'm sorry for any confusion, but a specific medical definition for 'Cyclin I' could not be found. Cyclins are a family of proteins that regulate the cell cycle in cells. They are so named because their levels fluctuate or cycle during different phases of the cell cycle. However, there is no specific cyclin referred to as "Cyclin I" in current medical and scientific literature.

There is a protein called "cyclin I" found in some organisms like Drosophila melanogaster (fruit flies), but it doesn't have a well-established role or equivalent in human cell cycle regulation. Therefore, it may not be relevant to provide a medical definition for a protein that is not directly involved in human physiology or pathophysiology.

Messenger RNA (mRNA) is a type of RNA (ribonucleic acid) that carries genetic information copied from DNA in the form of a series of three-base code "words," each of which specifies a particular amino acid. This information is used by the cell's machinery to construct proteins, a process known as translation. After being transcribed from DNA, mRNA travels out of the nucleus to the ribosomes in the cytoplasm where protein synthesis occurs. Once the protein has been synthesized, the mRNA may be degraded and recycled. Post-transcriptional modifications can also occur to mRNA, such as alternative splicing and addition of a 5' cap and a poly(A) tail, which can affect its stability, localization, and translation efficiency.

Mitosis is a type of cell division in which the genetic material of a single cell, called the mother cell, is equally distributed into two identical daughter cells. It's a fundamental process that occurs in multicellular organisms for growth, maintenance, and repair, as well as in unicellular organisms for reproduction.

The process of mitosis can be broken down into several stages: prophase, prometaphase, metaphase, anaphase, and telophase. During prophase, the chromosomes condense and become visible, and the nuclear envelope breaks down. In prometaphase, the nuclear membrane is completely disassembled, and the mitotic spindle fibers attach to the chromosomes at their centromeres.

During metaphase, the chromosomes align at the metaphase plate, an imaginary line equidistant from the two spindle poles. In anaphase, sister chromatids are pulled apart by the spindle fibers and move toward opposite poles of the cell. Finally, in telophase, new nuclear envelopes form around each set of chromosomes, and the chromosomes decondense and become less visible.

Mitosis is followed by cytokinesis, a process that divides the cytoplasm of the mother cell into two separate daughter cells. The result of mitosis and cytokinesis is two genetically identical cells, each with the same number and kind of chromosomes as the original parent cell.

Immunohistochemistry (IHC) is a technique used in pathology and laboratory medicine to identify specific proteins or antigens in tissue sections. It combines the principles of immunology and histology to detect the presence and location of these target molecules within cells and tissues. This technique utilizes antibodies that are specific to the protein or antigen of interest, which are then tagged with a detection system such as a chromogen or fluorophore. The stained tissue sections can be examined under a microscope, allowing for the visualization and analysis of the distribution and expression patterns of the target molecule in the context of the tissue architecture. Immunohistochemistry is widely used in diagnostic pathology to help identify various diseases, including cancer, infectious diseases, and immune-mediated disorders.

'Tumor cells, cultured' refers to the process of removing cancerous cells from a tumor and growing them in controlled laboratory conditions. This is typically done by isolating the tumor cells from a patient's tissue sample, then placing them in a nutrient-rich environment that promotes their growth and multiplication.

The resulting cultured tumor cells can be used for various research purposes, including the study of cancer biology, drug development, and toxicity testing. They provide a valuable tool for researchers to better understand the behavior and characteristics of cancer cells outside of the human body, which can lead to the development of more effective cancer treatments.

It is important to note that cultured tumor cells may not always behave exactly the same way as they do in the human body, so findings from cell culture studies must be validated through further research, such as animal models or clinical trials.

G0 phase, also known as the resting phase or quiescent stage, is a part of the cell cycle in which cells are not actively preparing to divide. In this phase, cells are metabolically active and can carry out their normal functions, but they are not synthesizing DNA or dividing. Cells in G0 phase have left the cell cycle and may remain in this phase for an indefinite period of time, until they receive signals to re-enter the cell cycle and begin preparing for division again.

It's important to note that not all cells go through the G0 phase. Some cells, such as stem cells and certain types of immune cells, may spend most of their time in G0 phase and only enter the cell cycle when they are needed to replace damaged or dying cells. Other cells, such as those lining the digestive tract, continuously divide and do not have a G0 phase.

Mantle cell lymphoma (MCL) is a type of non-Hodgkin lymphoma (NHL), which is a cancer of the lymphatic system. Specifically, MCL arises from abnormal B-lymphocytes (a type of white blood cell) that typically reside in the "mantle zone" of the lymph node. The malignant cells in MCL tend to have a characteristic genetic abnormality where the cyclin D1 gene is translocated to the immunoglobulin heavy chain gene locus, resulting in overexpression of cyclin D1 protein. This leads to uncontrolled cell division and proliferation.

Mantle cell lymphoma often presents with advanced-stage disease, involving multiple lymph nodes, bone marrow, and sometimes extranodal sites such as the gastrointestinal tract. Symptoms may include swollen lymph nodes, fatigue, weight loss, night sweats, and abdominal pain or discomfort.

Treatment for MCL typically involves a combination of chemotherapy, immunotherapy, and sometimes targeted therapy or stem cell transplantation. However, the prognosis for MCL is generally less favorable compared to other types of NHL, with a median overall survival of around 5-7 years.

Signal transduction is the process by which a cell converts an extracellular signal, such as a hormone or neurotransmitter, into an intracellular response. This involves a series of molecular events that transmit the signal from the cell surface to the interior of the cell, ultimately resulting in changes in gene expression, protein activity, or metabolism.

The process typically begins with the binding of the extracellular signal to a receptor located on the cell membrane. This binding event activates the receptor, which then triggers a cascade of intracellular signaling molecules, such as second messengers, protein kinases, and ion channels. These molecules amplify and propagate the signal, ultimately leading to the activation or inhibition of specific cellular responses.

Signal transduction pathways are highly regulated and can be modulated by various factors, including other signaling molecules, post-translational modifications, and feedback mechanisms. Dysregulation of these pathways has been implicated in a variety of diseases, including cancer, diabetes, and neurological disorders.

Down-regulation is a process that occurs in response to various stimuli, where the number or sensitivity of cell surface receptors or the expression of specific genes is decreased. This process helps maintain homeostasis within cells and tissues by reducing the ability of cells to respond to certain signals or molecules.

In the context of cell surface receptors, down-regulation can occur through several mechanisms:

1. Receptor internalization: After binding to their ligands, receptors can be internalized into the cell through endocytosis. Once inside the cell, these receptors may be degraded or recycled back to the cell surface in smaller numbers.
2. Reduced receptor synthesis: Down-regulation can also occur at the transcriptional level, where the expression of genes encoding for specific receptors is decreased, leading to fewer receptors being produced.
3. Receptor desensitization: Prolonged exposure to a ligand can lead to a decrease in receptor sensitivity or affinity, making it more difficult for the cell to respond to the signal.

In the context of gene expression, down-regulation refers to the decreased transcription and/or stability of specific mRNAs, leading to reduced protein levels. This process can be induced by various factors, including microRNA (miRNA)-mediated regulation, histone modification, or DNA methylation.

Down-regulation is an essential mechanism in many physiological processes and can also contribute to the development of several diseases, such as cancer and neurodegenerative disorders.

Cyclin-Dependent Kinase Inhibitor p16, also known as CDKN2A or INK4a, is a protein that regulates the cell cycle. It functions as an inhibitor of cyclin-dependent kinases (CDKs) 4 and 6, which are enzymes that play a crucial role in regulating the progression of the cell cycle.

The p16 protein is produced in response to various signals, including DNA damage and oncogene activation, and its main function is to prevent the phosphorylation and activation of the retinoblastoma protein (pRb) by CDK4/6. When pRb is not phosphorylated, it binds to and inhibits the E2F transcription factor, which results in the suppression of genes required for cell cycle progression.

Therefore, p16 acts as a tumor suppressor protein by preventing the uncontrolled proliferation of cells that can lead to cancer. Mutations or deletions in the CDKN2A gene, which encodes the p16 protein, have been found in many types of human cancers, including lung, breast, and head and neck cancers.

Western blotting is a laboratory technique used in molecular biology to detect and quantify specific proteins in a mixture of many different proteins. This technique is commonly used to confirm the expression of a protein of interest, determine its size, and investigate its post-translational modifications. The name "Western" blotting distinguishes this technique from Southern blotting (for DNA) and Northern blotting (for RNA).

The Western blotting procedure involves several steps:

1. Protein extraction: The sample containing the proteins of interest is first extracted, often by breaking open cells or tissues and using a buffer to extract the proteins.
2. Separation of proteins by electrophoresis: The extracted proteins are then separated based on their size by loading them onto a polyacrylamide gel and running an electric current through the gel (a process called sodium dodecyl sulfate-polyacrylamide gel electrophoresis or SDS-PAGE). This separates the proteins according to their molecular weight, with smaller proteins migrating faster than larger ones.
3. Transfer of proteins to a membrane: After separation, the proteins are transferred from the gel onto a nitrocellulose or polyvinylidene fluoride (PVDF) membrane using an electric current in a process called blotting. This creates a replica of the protein pattern on the gel but now immobilized on the membrane for further analysis.
4. Blocking: The membrane is then blocked with a blocking agent, such as non-fat dry milk or bovine serum albumin (BSA), to prevent non-specific binding of antibodies in subsequent steps.
5. Primary antibody incubation: A primary antibody that specifically recognizes the protein of interest is added and allowed to bind to its target protein on the membrane. This step may be performed at room temperature or 4°C overnight, depending on the antibody's properties.
6. Washing: The membrane is washed with a buffer to remove unbound primary antibodies.
7. Secondary antibody incubation: A secondary antibody that recognizes the primary antibody (often coupled to an enzyme or fluorophore) is added and allowed to bind to the primary antibody. This step may involve using a horseradish peroxidase (HRP)-conjugated or alkaline phosphatase (AP)-conjugated secondary antibody, depending on the detection method used later.
8. Washing: The membrane is washed again to remove unbound secondary antibodies.
9. Detection: A detection reagent is added to visualize the protein of interest by detecting the signal generated from the enzyme-conjugated or fluorophore-conjugated secondary antibody. This can be done using chemiluminescent, colorimetric, or fluorescent methods.
10. Analysis: The resulting image is analyzed to determine the presence and quantity of the protein of interest in the sample.

Western blotting is a powerful technique for identifying and quantifying specific proteins within complex mixtures. It can be used to study protein expression, post-translational modifications, protein-protein interactions, and more. However, it requires careful optimization and validation to ensure accurate and reproducible results.

Promoter regions in genetics refer to specific DNA sequences located near the transcription start site of a gene. They serve as binding sites for RNA polymerase and various transcription factors that regulate the initiation of gene transcription. These regulatory elements help control the rate of transcription and, therefore, the level of gene expression. Promoter regions can be composed of different types of sequences, such as the TATA box and CAAT box, and their organization and composition can vary between different genes and species.

Transfection is a term used in molecular biology that refers to the process of deliberately introducing foreign genetic material (DNA, RNA or artificial gene constructs) into cells. This is typically done using chemical or physical methods, such as lipofection or electroporation. Transfection is widely used in research and medical settings for various purposes, including studying gene function, producing proteins, developing gene therapies, and creating genetically modified organisms. It's important to note that transfection is different from transduction, which is the process of introducing genetic material into cells using viruses as vectors.

Proliferating Cell Nuclear Antigen (PCNA) is a protein that plays an essential role in the process of DNA replication and repair in eukaryotic cells. It functions as a cofactor for DNA polymerase delta, enhancing its activity during DNA synthesis. PCNA forms a sliding clamp around DNA, allowing it to move along the template and coordinate the actions of various enzymes involved in DNA metabolism.

PCNA is often used as a marker for cell proliferation because its levels increase in cells that are actively dividing or have been stimulated to enter the cell cycle. Immunostaining techniques can be used to detect PCNA and determine the proliferative status of tissues or cultures. In this context, 'proliferating' refers to the rapid multiplication of cells through cell division.

The cell nucleus is a membrane-bound organelle found in the eukaryotic cells (cells with a true nucleus). It contains most of the cell's genetic material, organized as DNA molecules in complex with proteins, RNA molecules, and histones to form chromosomes.

The primary function of the cell nucleus is to regulate and control the activities of the cell, including growth, metabolism, protein synthesis, and reproduction. It also plays a crucial role in the process of mitosis (cell division) by separating and protecting the genetic material during this process. The nuclear membrane, or nuclear envelope, surrounding the nucleus is composed of two lipid bilayers with numerous pores that allow for the selective transport of molecules between the nucleoplasm (nucleus interior) and the cytoplasm (cell exterior).

The cell nucleus is a vital structure in eukaryotic cells, and its dysfunction can lead to various diseases, including cancer and genetic disorders.

Apoptosis is a programmed and controlled cell death process that occurs in multicellular organisms. It is a natural process that helps maintain tissue homeostasis by eliminating damaged, infected, or unwanted cells. During apoptosis, the cell undergoes a series of morphological changes, including cell shrinkage, chromatin condensation, and fragmentation into membrane-bound vesicles called apoptotic bodies. These bodies are then recognized and engulfed by neighboring cells or phagocytic cells, preventing an inflammatory response. Apoptosis is regulated by a complex network of intracellular signaling pathways that involve proteins such as caspases, Bcl-2 family members, and inhibitors of apoptosis (IAPs).

A cell line is a culture of cells that are grown in a laboratory for use in research. These cells are usually taken from a single cell or group of cells, and they are able to divide and grow continuously in the lab. Cell lines can come from many different sources, including animals, plants, and humans. They are often used in scientific research to study cellular processes, disease mechanisms, and to test new drugs or treatments. Some common types of human cell lines include HeLa cells (which come from a cancer patient named Henrietta Lacks), HEK293 cells (which come from embryonic kidney cells), and HUVEC cells (which come from umbilical vein endothelial cells). It is important to note that cell lines are not the same as primary cells, which are cells that are taken directly from a living organism and have not been grown in the lab.

'Gene expression regulation' refers to the processes that control whether, when, and where a particular gene is expressed, meaning the production of a specific protein or functional RNA encoded by that gene. This complex mechanism can be influenced by various factors such as transcription factors, chromatin remodeling, DNA methylation, non-coding RNAs, and post-transcriptional modifications, among others. Proper regulation of gene expression is crucial for normal cellular function, development, and maintaining homeostasis in living organisms. Dysregulation of gene expression can lead to various diseases, including cancer and genetic disorders.

The G2 phase, also known as the "gap 2 phase," is a stage in the cell cycle that occurs after DNA replication (S phase) and before cell division (mitosis). During this phase, the cell prepares for mitosis by completing the synthesis of proteins and organelles needed for chromosome separation. The cell also checks for any errors or damage to the DNA before entering mitosis. This phase is a critical point in the cell cycle where proper regulation ensures the faithful transmission of genetic information from one generation of cells to the next. If significant DNA damage is detected during G2, the cell may undergo programmed cell death (apoptosis) instead of dividing.

E2F transcription factors are a family of proteins that play crucial roles in the regulation of the cell cycle, DNA repair, and apoptosis (programmed cell death). These factors bind to specific DNA sequences called E2F responsive elements, located in the promoter regions of target genes. They can act as either transcriptional activators or repressors, depending on which E2F family member is involved, the presence of co-factors, and the phase of the cell cycle.

The E2F family consists of eight members, divided into two groups based on their functions: activator E2Fs (E2F1, E2F2, and E2F3a) and repressor E2Fs (E2F3b, E2F4, E2F5, E2F6, and E2F7). Activator E2Fs promote the expression of genes required for cell cycle progression, DNA replication, and repair. Repressor E2Fs, on the other hand, inhibit the transcription of these same genes as well as genes involved in differentiation and apoptosis.

Dysregulation of E2F transcription factors has been implicated in various human diseases, including cancer. Overexpression or hyperactivation of activator E2Fs can lead to uncontrolled cell proliferation and tumorigenesis, while loss of function or inhibition of repressor E2Fs can result in impaired differentiation and increased susceptibility to malignancies. Therefore, understanding the roles and regulation of E2F transcription factors is essential for developing novel therapeutic strategies against cancer and other diseases associated with cell cycle dysregulation.

Beta-catenin is a protein that plays a crucial role in gene transcription and cell-cell adhesion. It is a key component of the Wnt signaling pathway, which regulates various processes such as cell proliferation, differentiation, and migration during embryonic development and tissue homeostasis in adults.

In the absence of Wnt signals, beta-catenin forms a complex with other proteins, including adenomatous polyposis coli (APC) and axin, which targets it for degradation by the proteasome. When Wnt ligands bind to their receptors, this complex is disrupted, allowing beta-catenin to accumulate in the cytoplasm and translocate to the nucleus. In the nucleus, beta-catenin interacts with T cell factor/lymphoid enhancer-binding factor (TCF/LEF) transcription factors to activate the transcription of target genes involved in cell fate determination, survival, and proliferation.

Mutations in the genes encoding components of the Wnt signaling pathway, including beta-catenin, have been implicated in various human diseases, such as cancer, developmental disorders, and degenerative conditions.

Cyclin-Dependent Kinase 6 (CDK6) is a type of enzyme known as a protein kinase, which adds phosphate groups to other proteins in the cell. CDK6 is primarily involved in regulating the cell cycle, the process by which cells divide and grow.

CDK6 functions by binding to cyclin proteins, forming active complexes that help drive the progression of the cell cycle from one phase to the next. Specifically, CDK6 plays a crucial role in the transition from the G1 phase to the S phase of the cell cycle, where DNA replication occurs.

CDK6 activity is tightly regulated by various mechanisms, including phosphorylation and dephosphorylation, as well as by binding to inhibitory proteins such as p16INK4a and p21CIP1. Dysregulation of CDK6 has been implicated in the development of several types of cancer, making it a potential target for cancer therapy.

Transcription factors are proteins that play a crucial role in regulating gene expression by controlling the transcription of DNA to messenger RNA (mRNA). They function by binding to specific DNA sequences, known as response elements, located in the promoter region or enhancer regions of target genes. This binding can either activate or repress the initiation of transcription, depending on the properties and interactions of the particular transcription factor. Transcription factors often act as part of a complex network of regulatory proteins that determine the precise spatiotemporal patterns of gene expression during development, differentiation, and homeostasis in an organism.

3T3 cells are a type of cell line that is commonly used in scientific research. The name "3T3" is derived from the fact that these cells were developed by treating mouse embryo cells with a chemical called trypsin and then culturing them in a flask at a temperature of 37 degrees Celsius.

Specifically, 3T3 cells are a type of fibroblast, which is a type of cell that is responsible for producing connective tissue in the body. They are often used in studies involving cell growth and proliferation, as well as in toxicity tests and drug screening assays.

One particularly well-known use of 3T3 cells is in the 3T3-L1 cell line, which is a subtype of 3T3 cells that can be differentiated into adipocytes (fat cells) under certain conditions. These cells are often used in studies of adipose tissue biology and obesity.

It's important to note that because 3T3 cells are a type of immortalized cell line, they do not always behave exactly the same way as primary cells (cells that are taken directly from a living organism). As such, researchers must be careful when interpreting results obtained using 3T3 cells and consider any potential limitations or artifacts that may arise due to their use.

Protein binding, in the context of medical and biological sciences, refers to the interaction between a protein and another molecule (known as the ligand) that results in a stable complex. This process is often reversible and can be influenced by various factors such as pH, temperature, and concentration of the involved molecules.

In clinical chemistry, protein binding is particularly important when it comes to drugs, as many of them bind to proteins (especially albumin) in the bloodstream. The degree of protein binding can affect a drug's distribution, metabolism, and excretion, which in turn influence its therapeutic effectiveness and potential side effects.

Protein-bound drugs may be less available for interaction with their target tissues, as only the unbound or "free" fraction of the drug is active. Therefore, understanding protein binding can help optimize dosing regimens and minimize adverse reactions.

Glycogen Synthase Kinase 3 (GSK-3) is a serine/threonine protein kinase that plays a crucial role in the regulation of several cellular processes, including glycogen metabolism, cell signaling, gene transcription, and apoptosis. It was initially discovered as a key enzyme involved in glycogen metabolism due to its ability to phosphorylate and inhibit glycogen synthase, an enzyme responsible for the synthesis of glycogen from glucose.

GSK-3 exists in two isoforms, GSK-3α and GSK-3β, which share a high degree of sequence similarity and are widely expressed in various tissues. Both isoforms are constitutively active under normal conditions and are regulated through inhibitory phosphorylation by several upstream signaling pathways, such as insulin, Wnt, and Hedgehog signaling.

Dysregulation of GSK-3 has been implicated in the pathogenesis of various diseases, including diabetes, neurodegenerative disorders, and cancer. In recent years, GSK-3 has emerged as an attractive therapeutic target for the development of novel drugs to treat these conditions.

The Ki-67 antigen is a cellular protein that is expressed in all active phases of the cell cycle (G1, S, G2, and M), but not in the resting phase (G0). It is often used as a marker for cell proliferation and can be found in high concentrations in rapidly dividing cells. Immunohistochemical staining for Ki-67 can help to determine the growth fraction of a group of cells, which can be useful in the diagnosis and prognosis of various malignancies, including cancer. The level of Ki-67 expression is often associated with the aggressiveness of the tumor and its response to treatment.

Neoplastic cell transformation is a process in which a normal cell undergoes genetic alterations that cause it to become cancerous or malignant. This process involves changes in the cell's DNA that result in uncontrolled cell growth and division, loss of contact inhibition, and the ability to invade surrounding tissues and metastasize (spread) to other parts of the body.

Neoplastic transformation can occur as a result of various factors, including genetic mutations, exposure to carcinogens, viral infections, chronic inflammation, and aging. These changes can lead to the activation of oncogenes or the inactivation of tumor suppressor genes, which regulate cell growth and division.

The transformation of normal cells into cancerous cells is a complex and multi-step process that involves multiple genetic and epigenetic alterations. It is characterized by several hallmarks, including sustained proliferative signaling, evasion of growth suppressors, resistance to cell death, enabling replicative immortality, induction of angiogenesis, activation of invasion and metastasis, reprogramming of energy metabolism, and evading immune destruction.

Neoplastic cell transformation is a fundamental concept in cancer biology and is critical for understanding the molecular mechanisms underlying cancer development and progression. It also has important implications for cancer diagnosis, prognosis, and treatment, as identifying the specific genetic alterations that underlie neoplastic transformation can help guide targeted therapies and personalized medicine approaches.

Genetic transcription is the process by which the information in a strand of DNA is used to create a complementary RNA molecule. This process is the first step in gene expression, where the genetic code in DNA is converted into a form that can be used to produce proteins or functional RNAs.

During transcription, an enzyme called RNA polymerase binds to the DNA template strand and reads the sequence of nucleotide bases. As it moves along the template, it adds complementary RNA nucleotides to the growing RNA chain, creating a single-stranded RNA molecule that is complementary to the DNA template strand. Once transcription is complete, the RNA molecule may undergo further processing before it can be translated into protein or perform its functional role in the cell.

Transcription can be either "constitutive" or "regulated." Constitutive transcription occurs at a relatively constant rate and produces essential proteins that are required for basic cellular functions. Regulated transcription, on the other hand, is subject to control by various intracellular and extracellular signals, allowing cells to respond to changing environmental conditions or developmental cues.

Breast neoplasms refer to abnormal growths in the breast tissue that can be benign or malignant. Benign breast neoplasms are non-cancerous tumors or growths, while malignant breast neoplasms are cancerous tumors that can invade surrounding tissues and spread to other parts of the body.

Breast neoplasms can arise from different types of cells in the breast, including milk ducts, milk sacs (lobules), or connective tissue. The most common type of breast cancer is ductal carcinoma, which starts in the milk ducts and can spread to other parts of the breast and nearby structures.

Breast neoplasms are usually detected through screening methods such as mammography, ultrasound, or MRI, or through self-examination or clinical examination. Treatment options for breast neoplasms depend on several factors, including the type and stage of the tumor, the patient's age and overall health, and personal preferences. Treatment may include surgery, radiation therapy, chemotherapy, hormone therapy, or targeted therapy.

F-box proteins are a family of proteins that are characterized by the presence of an F-box domain, which is a motif of about 40-50 amino acids. This domain is responsible for binding to Skp1, a component of the SCF (Skp1-Cul1-F-box protein) E3 ubiquitin ligase complex. The F-box proteins serve as the substrate recognition subunit of this complex and are involved in targeting specific proteins for ubiquitination and subsequent degradation by the 26S proteasome.

There are multiple types of F-box proteins, including FBXW (also known as β-TrCP), FBXL, and FBLX, each with different substrate specificities. These proteins play important roles in various cellular processes such as cell cycle regulation, signal transduction, and DNA damage response by controlling the stability of key regulatory proteins.

Abnormal regulation of F-box proteins has been implicated in several human diseases, including cancer, developmental disorders, and neurodegenerative diseases.

"Cells, cultured" is a medical term that refers to cells that have been removed from an organism and grown in controlled laboratory conditions outside of the body. This process is called cell culture and it allows scientists to study cells in a more controlled and accessible environment than they would have inside the body. Cultured cells can be derived from a variety of sources, including tissues, organs, or fluids from humans, animals, or cell lines that have been previously established in the laboratory.

Cell culture involves several steps, including isolation of the cells from the tissue, purification and characterization of the cells, and maintenance of the cells in appropriate growth conditions. The cells are typically grown in specialized media that contain nutrients, growth factors, and other components necessary for their survival and proliferation. Cultured cells can be used for a variety of purposes, including basic research, drug development and testing, and production of biological products such as vaccines and gene therapies.

It is important to note that cultured cells may behave differently than they do in the body, and results obtained from cell culture studies may not always translate directly to human physiology or disease. Therefore, it is essential to validate findings from cell culture experiments using additional models and ultimately in clinical trials involving human subjects.

Tumor suppressor protein p53, also known as p53 or tumor protein p53, is a nuclear phosphoprotein that plays a crucial role in preventing cancer development and maintaining genomic stability. It does so by regulating the cell cycle and acting as a transcription factor for various genes involved in apoptosis (programmed cell death), DNA repair, and cell senescence (permanent cell growth arrest).

In response to cellular stress, such as DNA damage or oncogene activation, p53 becomes activated and accumulates in the nucleus. Activated p53 can then bind to specific DNA sequences and promote the transcription of target genes that help prevent the proliferation of potentially cancerous cells. These targets include genes involved in cell cycle arrest (e.g., CDKN1A/p21), apoptosis (e.g., BAX, PUMA), and DNA repair (e.g., GADD45).

Mutations in the TP53 gene, which encodes p53, are among the most common genetic alterations found in human cancers. These mutations often lead to a loss or reduction of p53's tumor suppressive functions, allowing cancer cells to proliferate uncontrollably and evade apoptosis. As a result, p53 has been referred to as "the guardian of the genome" due to its essential role in preventing tumorigenesis.

Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) is a laboratory technique used in molecular biology to amplify and detect specific DNA sequences. This technique is particularly useful for the detection and quantification of RNA viruses, as well as for the analysis of gene expression.

The process involves two main steps: reverse transcription and polymerase chain reaction (PCR). In the first step, reverse transcriptase enzyme is used to convert RNA into complementary DNA (cDNA) by reading the template provided by the RNA molecule. This cDNA then serves as a template for the PCR amplification step.

In the second step, the PCR reaction uses two primers that flank the target DNA sequence and a thermostable polymerase enzyme to repeatedly copy the targeted cDNA sequence. The reaction mixture is heated and cooled in cycles, allowing the primers to anneal to the template, and the polymerase to extend the new strand. This results in exponential amplification of the target DNA sequence, making it possible to detect even small amounts of RNA or cDNA.

RT-PCR is a sensitive and specific technique that has many applications in medical research and diagnostics, including the detection of viruses such as HIV, hepatitis C virus, and SARS-CoV-2 (the virus that causes COVID-19). It can also be used to study gene expression, identify genetic mutations, and diagnose genetic disorders.

Molecular sequence data refers to the specific arrangement of molecules, most commonly nucleotides in DNA or RNA, or amino acids in proteins, that make up a biological macromolecule. This data is generated through laboratory techniques such as sequencing, and provides information about the exact order of the constituent molecules. This data is crucial in various fields of biology, including genetics, evolution, and molecular biology, allowing for comparisons between different organisms, identification of genetic variations, and studies of gene function and regulation.

DNA-binding proteins are a type of protein that have the ability to bind to DNA (deoxyribonucleic acid), the genetic material of organisms. These proteins play crucial roles in various biological processes, such as regulation of gene expression, DNA replication, repair and recombination.

The binding of DNA-binding proteins to specific DNA sequences is mediated by non-covalent interactions, including electrostatic, hydrogen bonding, and van der Waals forces. The specificity of binding is determined by the recognition of particular nucleotide sequences or structural features of the DNA molecule.

DNA-binding proteins can be classified into several categories based on their structure and function, such as transcription factors, histones, and restriction enzymes. Transcription factors are a major class of DNA-binding proteins that regulate gene expression by binding to specific DNA sequences in the promoter region of genes and recruiting other proteins to modulate transcription. Histones are DNA-binding proteins that package DNA into nucleosomes, the basic unit of chromatin structure. Restriction enzymes are DNA-binding proteins that recognize and cleave specific DNA sequences, and are widely used in molecular biology research and biotechnology applications.

Small interfering RNA (siRNA) is a type of short, double-stranded RNA molecule that plays a role in the RNA interference (RNAi) pathway. The RNAi pathway is a natural cellular process that regulates gene expression by targeting and destroying specific messenger RNA (mRNA) molecules, thereby preventing the translation of those mRNAs into proteins.

SiRNAs are typically 20-25 base pairs in length and are generated from longer double-stranded RNA precursors called hairpin RNAs or dsRNAs by an enzyme called Dicer. Once generated, siRNAs associate with a protein complex called the RNA-induced silencing complex (RISC), which uses one strand of the siRNA (the guide strand) to recognize and bind to complementary sequences in the target mRNA. The RISC then cleaves the target mRNA, leading to its degradation and the inhibition of protein synthesis.

SiRNAs have emerged as a powerful tool for studying gene function and have shown promise as therapeutic agents for a variety of diseases, including viral infections, cancer, and genetic disorders. However, their use as therapeutics is still in the early stages of development, and there are challenges associated with delivering siRNAs to specific cells and tissues in the body.

Proto-oncogene proteins, such as c-Myc, are crucial regulators of normal cell growth, differentiation, and apoptosis (programmed cell death). When proto-oncogenes undergo mutations or alterations in their regulation, they can become overactive or overexpressed, leading to the formation of oncogenes. Oncogenic forms of c-Myc contribute to uncontrolled cell growth and division, which can ultimately result in cancer development.

The c-Myc protein is a transcription factor that binds to specific DNA sequences, influencing the expression of target genes involved in various cellular processes, such as:

1. Cell cycle progression: c-Myc promotes the expression of genes required for the G1 to S phase transition, driving cells into the DNA synthesis and division phase.
2. Metabolism: c-Myc regulates genes associated with glucose metabolism, glycolysis, and mitochondrial function, enhancing energy production in rapidly dividing cells.
3. Apoptosis: c-Myc can either promote or inhibit apoptosis, depending on the cellular context and the presence of other regulatory factors.
4. Differentiation: c-Myc generally inhibits differentiation by repressing genes that are necessary for specialized cell functions.
5. Angiogenesis: c-Myc can induce the expression of pro-angiogenic factors, promoting the formation of new blood vessels to support tumor growth.

Dysregulation of c-Myc is frequently observed in various types of cancer, making it an important therapeutic target for cancer treatment.

NIH 3T3 cells are a type of mouse fibroblast cell line that was developed by the National Institutes of Health (NIH). The "3T3" designation refers to the fact that these cells were derived from embryonic Swiss mouse tissue and were able to be passaged (i.e., subcultured) more than three times in tissue culture.

NIH 3T3 cells are widely used in scientific research, particularly in studies involving cell growth and differentiation, signal transduction, and gene expression. They have also been used as a model system for studying the effects of various chemicals and drugs on cell behavior. NIH 3T3 cells are known to be relatively easy to culture and maintain, and they have a stable, flat morphology that makes them well-suited for use in microscopy studies.

It is important to note that, as with any cell line, it is essential to verify the identity and authenticity of NIH 3T3 cells before using them in research, as contamination or misidentification can lead to erroneous results.

E2F1 is a member of the E2F family of transcription factors, which are involved in the regulation of cell cycle progression and apoptosis (programmed cell death). Specifically, E2F1 plays a role as a transcriptional activator, binding to specific DNA sequences and promoting the expression of genes required for the G1/S transition of the cell cycle.

In more detail, E2F1 forms a complex with a retinoblastoma protein (pRb) in the G0 and early G1 phases of the cell cycle. When pRb is phosphorylated by cyclin-dependent kinases during the late G1 phase, E2F1 is released and can then bind to its target DNA sequences and activate transcription of genes involved in DNA replication and cell cycle progression.

However, if E2F1 is overexpressed or activated inappropriately, it can also promote apoptosis, making it a key player in both cell proliferation and cell death pathways. Dysregulation of E2F1 has been implicated in the development of various human cancers, including breast, lung, and prostate cancer.

A mutation is a permanent change in the DNA sequence of an organism's genome. Mutations can occur spontaneously or be caused by environmental factors such as exposure to radiation, chemicals, or viruses. They may have various effects on the organism, ranging from benign to harmful, depending on where they occur and whether they alter the function of essential proteins. In some cases, mutations can increase an individual's susceptibility to certain diseases or disorders, while in others, they may confer a survival advantage. Mutations are the driving force behind evolution, as they introduce new genetic variability into populations, which can then be acted upon by natural selection.

Nuclear proteins are a category of proteins that are primarily found in the nucleus of a eukaryotic cell. They play crucial roles in various nuclear functions, such as DNA replication, transcription, repair, and RNA processing. This group includes structural proteins like lamins, which form the nuclear lamina, and regulatory proteins, such as histones and transcription factors, that are involved in gene expression. Nuclear localization signals (NLS) often help target these proteins to the nucleus by interacting with importin proteins during active transport across the nuclear membrane.

Enzyme activation refers to the process by which an enzyme becomes biologically active and capable of carrying out its specific chemical or biological reaction. This is often achieved through various post-translational modifications, such as proteolytic cleavage, phosphorylation, or addition of cofactors or prosthetic groups to the enzyme molecule. These modifications can change the conformation or structure of the enzyme, exposing or creating a binding site for the substrate and allowing the enzymatic reaction to occur.

For example, in the case of proteolytic cleavage, an inactive precursor enzyme, known as a zymogen, is cleaved into its active form by a specific protease. This is seen in enzymes such as trypsin and chymotrypsin, which are initially produced in the pancreas as inactive precursors called trypsinogen and chymotrypsinogen, respectively. Once they reach the small intestine, they are activated by enteropeptidase, a protease that cleaves a specific peptide bond, releasing the active enzyme.

Phosphorylation is another common mechanism of enzyme activation, where a phosphate group is added to a specific serine, threonine, or tyrosine residue on the enzyme by a protein kinase. This modification can alter the conformation of the enzyme and create a binding site for the substrate, allowing the enzymatic reaction to occur.

Enzyme activation is a crucial process in many biological pathways, as it allows for precise control over when and where specific reactions take place. It also provides a mechanism for regulating enzyme activity in response to various signals and stimuli, such as hormones, neurotransmitters, or changes in the intracellular environment.

Enzyme inhibitors are substances that bind to an enzyme and decrease its activity, preventing it from catalyzing a chemical reaction in the body. They can work by several mechanisms, including blocking the active site where the substrate binds, or binding to another site on the enzyme to change its shape and prevent substrate binding. Enzyme inhibitors are often used as drugs to treat various medical conditions, such as high blood pressure, abnormal heart rhythms, and bacterial infections. They can also be found naturally in some foods and plants, and can be used in research to understand enzyme function and regulation.

A base sequence in the context of molecular biology refers to the specific order of nucleotides in a DNA or RNA molecule. In DNA, these nucleotides are adenine (A), guanine (G), cytosine (C), and thymine (T). In RNA, uracil (U) takes the place of thymine. The base sequence contains genetic information that is transcribed into RNA and ultimately translated into proteins. It is the exact order of these bases that determines the genetic code and thus the function of the DNA or RNA molecule.

Flow cytometry is a medical and research technique used to measure physical and chemical characteristics of cells or particles, one cell at a time, as they flow in a fluid stream through a beam of light. The properties measured include:

* Cell size (light scatter)
* Cell internal complexity (granularity, also light scatter)
* Presence or absence of specific proteins or other molecules on the cell surface or inside the cell (using fluorescent antibodies or other fluorescent probes)

The technique is widely used in cell counting, cell sorting, protein engineering, biomarker discovery and monitoring disease progression, particularly in hematology, immunology, and cancer research.

Transcription factor DP1 (TFDP1) is not a specific medical term, but it is a term used in molecular biology and genetics. TFDP1 is a protein that functions as a transcription factor, which means it helps regulate the expression of genes by binding to specific DNA sequences and controlling the rate of transcription of those genes into messenger RNA (mRNA).

TFDP1 typically forms a complex with another transcription factor called E2F, and this complex plays a critical role in regulating the cell cycle and promoting cell division. TFDP1 can act as both a transcriptional activator and repressor, depending on which E2F family member it binds to and the specific context of the cell.

Mutations or dysregulation of TFDP1 have been implicated in various human diseases, including cancer. For example, overexpression of TFDP1 has been observed in several types of cancer, such as breast, lung, and prostate cancer, and is often associated with poor clinical outcomes. Therefore, understanding the role of TFDP1 in gene regulation and cellular processes may provide insights into the development of new therapeutic strategies for treating human diseases.

Fibroblasts are specialized cells that play a critical role in the body's immune response and wound healing process. They are responsible for producing and maintaining the extracellular matrix (ECM), which is the non-cellular component present within all tissues and organs, providing structural support and biochemical signals for surrounding cells.

Fibroblasts produce various ECM proteins such as collagens, elastin, fibronectin, and laminins, forming a complex network of fibers that give tissues their strength and flexibility. They also help in the regulation of tissue homeostasis by controlling the turnover of ECM components through the process of remodeling.

In response to injury or infection, fibroblasts become activated and start to proliferate rapidly, migrating towards the site of damage. Here, they participate in the inflammatory response, releasing cytokines and chemokines that attract immune cells to the area. Additionally, they deposit new ECM components to help repair the damaged tissue and restore its functionality.

Dysregulation of fibroblast activity has been implicated in several pathological conditions, including fibrosis (excessive scarring), cancer (where they can contribute to tumor growth and progression), and autoimmune diseases (such as rheumatoid arthritis).

Human chromosome pair 11 consists of two rod-shaped structures present in the nucleus of each cell in the human body. Each member of the pair is a single chromosome, and together they contain the genetic material that is inherited from both parents. They are located on the eleventh position in the standard karyotype, which is a visual representation of the 23 pairs of human chromosomes.

Chromosome 11 is one of the largest human chromosomes and contains an estimated 135 million base pairs. It contains approximately 1,400 genes that provide instructions for making proteins, as well as many non-coding RNA molecules that play a role in regulating gene expression.

Chromosome 11 is known to contain several important genes and genetic regions associated with various human diseases and conditions. For example, it contains the Wilms' tumor 1 (WT1) gene, which is associated with kidney cancer in children, and the neurofibromatosis type 1 (NF1) gene, which is associated with a genetic disorder that causes benign tumors to grow on nerves throughout the body. Additionally, chromosome 11 contains the region where the ABO blood group genes are located, which determine a person's blood type.

It's worth noting that human chromosomes come in pairs because they contain two copies of each gene, one inherited from the mother and one from the father. This redundancy allows for genetic diversity and provides a backup copy of essential genes, ensuring their proper function and maintaining the stability of the genome.

Gene expression is the process by which the information encoded in a gene is used to synthesize a functional gene product, such as a protein or RNA molecule. This process involves several steps: transcription, RNA processing, and translation. During transcription, the genetic information in DNA is copied into a complementary RNA molecule, known as messenger RNA (mRNA). The mRNA then undergoes RNA processing, which includes adding a cap and tail to the mRNA and splicing out non-coding regions called introns. The resulting mature mRNA is then translated into a protein on ribosomes in the cytoplasm through the process of translation.

The regulation of gene expression is a complex and highly controlled process that allows cells to respond to changes in their environment, such as growth factors, hormones, and stress signals. This regulation can occur at various stages of gene expression, including transcriptional activation or repression, RNA processing, mRNA stability, and translation. Dysregulation of gene expression has been implicated in many diseases, including cancer, genetic disorders, and neurological conditions.

Up-regulation is a term used in molecular biology and medicine to describe an increase in the expression or activity of a gene, protein, or receptor in response to a stimulus. This can occur through various mechanisms such as increased transcription, translation, or reduced degradation of the molecule. Up-regulation can have important functional consequences, for example, enhancing the sensitivity or response of a cell to a hormone, neurotransmitter, or drug. It is a normal physiological process that can also be induced by disease or pharmacological interventions.

Retinoblastoma-like protein p107, also known as RBL1 or p107, is a tumor suppressor protein that belongs to the family of "pocket proteins." This protein is encoded by the RBL1 gene in humans. It plays a crucial role in regulating the cell cycle and preventing uncontrolled cell growth, which can lead to cancer.

The p107 protein is structurally similar to the retinoblastoma protein (pRb) and functions in a related manner. Both proteins interact with E2F transcription factors to control the expression of genes required for DNA replication and cell division. When the p107 protein is phosphorylated by cyclin-dependent kinases during the G1 phase of the cell cycle, it releases E2F transcription factors, allowing them to activate the transcription of target genes necessary for S phase entry and DNA replication.

Retinoblastoma-like protein p107 is often inactivated or mutated in various human cancers, including retinoblastoma, small cell lung cancer, and certain types of sarcomas. Loss of p107 function can lead to uncontrolled cell growth and tumor formation. However, it's important to note that the role of p107 in cancer development is complex and may depend on its interactions with other proteins and signaling pathways.

CDC25 phosphatases are a group of enzymes that play crucial roles in the regulation of the cell cycle, which is the series of events that cells undergo as they grow and divide. Specifically, CDC25 phosphatases function to remove inhibitory phosphates from certain cyclin-dependent kinases (CDKs), thereby activating them and allowing the cell cycle to progress.

There are three main types of CDC25 phosphatases in humans, known as CDC25A, CDC25B, and CDC25C. These enzymes are named after the original yeast homolog, called Cdc25, which was discovered to be essential for cell cycle progression.

CDC25 phosphatases are tightly regulated during the cell cycle, with their activity being controlled by various mechanisms such as phosphorylation, protein-protein interactions, and subcellular localization. Dysregulation of CDC25 phosphatases has been implicated in several human diseases, including cancer, where they can contribute to uncontrolled cell growth and division. Therefore, understanding the functions and regulation of CDC25 phosphatases is an important area of research in molecular biology and medicine.

A neoplasm is a tumor or growth that is formed by an abnormal and excessive proliferation of cells, which can be benign or malignant. Neoplasm proteins are therefore any proteins that are expressed or produced in these neoplastic cells. These proteins can play various roles in the development, progression, and maintenance of neoplasms.

Some neoplasm proteins may contribute to the uncontrolled cell growth and division seen in cancer, such as oncogenic proteins that promote cell cycle progression or inhibit apoptosis (programmed cell death). Others may help the neoplastic cells evade the immune system, allowing them to proliferate undetected. Still others may be involved in angiogenesis, the formation of new blood vessels that supply the tumor with nutrients and oxygen.

Neoplasm proteins can also serve as biomarkers for cancer diagnosis, prognosis, or treatment response. For example, the presence or level of certain neoplasm proteins in biological samples such as blood or tissue may indicate the presence of a specific type of cancer, help predict the likelihood of cancer recurrence, or suggest whether a particular therapy will be effective.

Overall, understanding the roles and behaviors of neoplasm proteins can provide valuable insights into the biology of cancer and inform the development of new diagnostic and therapeutic strategies.

Retinoblastoma-Binding Protein 1 (RBP1) is not a medical term itself, but it is a protein that has been studied in the context of cancer research, including retinoblastoma. According to scientific and medical literature, RBP1 is a protein that binds to the retinoblastoma protein (pRb), which is a tumor suppressor protein. The binding of RBP1 to pRb can influence the activity of this tumor suppressor and contribute to the regulation of the cell cycle and cell growth.

In the case of retinoblastoma, mutations in the RB1 gene, which encodes for the pRb protein, have been identified as a cause of this rare eye cancer in children. However, the role of RBP1 in retinoblastoma or other cancers is not well-defined and requires further research to fully understand its implications in disease development and potential therapeutic targets.

The proteasome endopeptidase complex is a large protein complex found in the cells of eukaryotic organisms, as well as in archaea and some bacteria. It plays a crucial role in the degradation of damaged or unneeded proteins through a process called proteolysis. The proteasome complex contains multiple subunits, including both regulatory and catalytic particles.

The catalytic core of the proteasome is composed of four stacked rings, each containing seven subunits, forming a structure known as the 20S core particle. Three of these rings are made up of beta-subunits that contain the proteolytic active sites, while the fourth ring consists of alpha-subunits that control access to the interior of the complex.

The regulatory particles, called 19S or 11S regulators, cap the ends of the 20S core particle and are responsible for recognizing, unfolding, and translocating targeted proteins into the catalytic chamber. The proteasome endopeptidase complex can cleave peptide bonds in various ways, including hydrolysis of ubiquitinated proteins, which is an essential mechanism for maintaining protein quality control and regulating numerous cellular processes, such as cell cycle progression, signal transduction, and stress response.

In summary, the proteasome endopeptidase complex is a crucial intracellular machinery responsible for targeted protein degradation through proteolysis, contributing to various essential regulatory functions in cells.

S-phase kinase-associated proteins (Skp2) are a group of proteins that are associated with the S-phase kinase, which is a type of enzyme that helps to regulate the cell cycle. Specifically, Skp2 is involved in the ubiquitination and degradation of certain proteins that play a role in controlling the progression of the cell cycle.

Skp2 is a member of the F-box protein family, which are components of the Skp1-Cul1-F-box (SCF) complex, a type of E3 ubiquitin ligase. The SCF complex recognizes and binds to specific proteins, tagging them for ubiquitination and subsequent degradation by the proteasome.

One of the key targets of Skp2 is the tumor suppressor protein p27, which inhibits the activity of cyclin-dependent kinases (CDKs) and helps to regulate the transition from the G1 phase to the S phase of the cell cycle. By targeting p27 for degradation, Skp2 promotes the progression of the cell cycle and has been implicated in the development of various types of cancer.

Overall, Skp2 plays a critical role in regulating the cell cycle and has important implications for the development and treatment of various diseases, including cancer.

HeLa cells are a type of immortalized cell line used in scientific research. They are derived from a cancer that developed in the cervical tissue of Henrietta Lacks, an African-American woman, in 1951. After her death, cells taken from her tumor were found to be capable of continuous division and growth in a laboratory setting, making them an invaluable resource for medical research.

HeLa cells have been used in a wide range of scientific studies, including research on cancer, viruses, genetics, and drug development. They were the first human cell line to be successfully cloned and are able to grow rapidly in culture, doubling their population every 20-24 hours. This has made them an essential tool for many areas of biomedical research.

It is important to note that while HeLa cells have been instrumental in numerous scientific breakthroughs, the story of their origin raises ethical questions about informed consent and the use of human tissue in research.

Cell cycle checkpoints are control mechanisms that regulate the cell cycle and ensure the accurate and timely progression through different phases of the cell cycle. These checkpoints monitor specific cellular events, such as DNA replication and damage, chromosome separation, and proper attachment of the mitotic spindle to the chromosomes. If any of these events fail to occur properly or are delayed, the cell cycle checkpoints trigger a response that can halt the cell cycle until the problem is resolved. This helps to prevent cells with damaged or incomplete genomes from dividing and potentially becoming cancerous.

There are three main types of cell cycle checkpoints:

1. G1 Checkpoint: Also known as the restriction point, this checkpoint controls the transition from the G1 phase to the S phase of the cell cycle. It monitors the availability of nutrients, growth factors, and the integrity of the genome before allowing the cell to proceed into DNA replication.
2. G2 Checkpoint: This checkpoint regulates the transition from the G2 phase to the M phase of the cell cycle. It checks for completion of DNA replication and absence of DNA damage before allowing the cell to enter mitosis.
3. Mitotic (M) Checkpoint: Also known as the spindle assembly checkpoint, this checkpoint ensures that all chromosomes are properly attached to the mitotic spindle before anaphase begins. It prevents the separation of sister chromatids until all kinetochores are correctly attached and tension is established between them.

Cell cycle checkpoints play a crucial role in maintaining genomic stability, preventing tumorigenesis, and ensuring proper cell division. Dysregulation of these checkpoints can lead to various diseases, including cancer.

Tumor markers are substances that can be found in the body and their presence can indicate the presence of certain types of cancer or other conditions. Biological tumor markers refer to those substances that are produced by cancer cells or by other cells in response to cancer or certain benign (non-cancerous) conditions. These markers can be found in various bodily fluids such as blood, urine, or tissue samples.

Examples of biological tumor markers include:

1. Proteins: Some tumor markers are proteins that are produced by cancer cells or by other cells in response to the presence of cancer. For example, prostate-specific antigen (PSA) is a protein produced by normal prostate cells and in higher amounts by prostate cancer cells.
2. Genetic material: Tumor markers can also include genetic material such as DNA, RNA, or microRNA that are shed by cancer cells into bodily fluids. For example, circulating tumor DNA (ctDNA) is genetic material from cancer cells that can be found in the bloodstream.
3. Metabolites: Tumor markers can also include metabolic products produced by cancer cells or by other cells in response to cancer. For example, lactate dehydrogenase (LDH) is an enzyme that is released into the bloodstream when cancer cells break down glucose for energy.

It's important to note that tumor markers are not specific to cancer and can be elevated in non-cancerous conditions as well. Therefore, they should not be used alone to diagnose cancer but rather as a tool in conjunction with other diagnostic tests and clinical evaluations.

Transgenic mice are genetically modified rodents that have incorporated foreign DNA (exogenous DNA) into their own genome. This is typically done through the use of recombinant DNA technology, where a specific gene or genetic sequence of interest is isolated and then introduced into the mouse embryo. The resulting transgenic mice can then express the protein encoded by the foreign gene, allowing researchers to study its function in a living organism.

The process of creating transgenic mice usually involves microinjecting the exogenous DNA into the pronucleus of a fertilized egg, which is then implanted into a surrogate mother. The offspring that result from this procedure are screened for the presence of the foreign DNA, and those that carry the desired genetic modification are used to establish a transgenic mouse line.

Transgenic mice have been widely used in biomedical research to model human diseases, study gene function, and test new therapies. They provide a valuable tool for understanding complex biological processes and developing new treatments for a variety of medical conditions.

Trans-activators are proteins that increase the transcriptional activity of a gene or a set of genes. They do this by binding to specific DNA sequences and interacting with the transcription machinery, thereby enhancing the recruitment and assembly of the complexes needed for transcription. In some cases, trans-activators can also modulate the chromatin structure to make the template more accessible to the transcription machinery.

In the context of HIV (Human Immunodeficiency Virus) infection, the term "trans-activator" is often used specifically to refer to the Tat protein. The Tat protein is a viral regulatory protein that plays a critical role in the replication of HIV by activating the transcription of the viral genome. It does this by binding to a specific RNA structure called the Trans-Activation Response Element (TAR) located at the 5' end of all nascent HIV transcripts, and recruiting cellular cofactors that enhance the processivity and efficiency of RNA polymerase II, leading to increased viral gene expression.

In the field of medicine, "time factors" refer to the duration of symptoms or time elapsed since the onset of a medical condition, which can have significant implications for diagnosis and treatment. Understanding time factors is crucial in determining the progression of a disease, evaluating the effectiveness of treatments, and making critical decisions regarding patient care.

For example, in stroke management, "time is brain," meaning that rapid intervention within a specific time frame (usually within 4.5 hours) is essential to administering tissue plasminogen activator (tPA), a clot-busting drug that can minimize brain damage and improve patient outcomes. Similarly, in trauma care, the "golden hour" concept emphasizes the importance of providing definitive care within the first 60 minutes after injury to increase survival rates and reduce morbidity.

Time factors also play a role in monitoring the progression of chronic conditions like diabetes or heart disease, where regular follow-ups and assessments help determine appropriate treatment adjustments and prevent complications. In infectious diseases, time factors are crucial for initiating antibiotic therapy and identifying potential outbreaks to control their spread.

Overall, "time factors" encompass the significance of recognizing and acting promptly in various medical scenarios to optimize patient outcomes and provide effective care.

Recombinant fusion proteins are artificially created biomolecules that combine the functional domains or properties of two or more different proteins into a single protein entity. They are generated through recombinant DNA technology, where the genes encoding the desired protein domains are linked together and expressed as a single, chimeric gene in a host organism, such as bacteria, yeast, or mammalian cells.

The resulting fusion protein retains the functional properties of its individual constituent proteins, allowing for novel applications in research, diagnostics, and therapeutics. For instance, recombinant fusion proteins can be designed to enhance protein stability, solubility, or immunogenicity, making them valuable tools for studying protein-protein interactions, developing targeted therapies, or generating vaccines against infectious diseases or cancer.

Examples of recombinant fusion proteins include:

1. Etaglunatide (ABT-523): A soluble Fc fusion protein that combines the heavy chain fragment crystallizable region (Fc) of an immunoglobulin with the extracellular domain of the human interleukin-6 receptor (IL-6R). This fusion protein functions as a decoy receptor, neutralizing IL-6 and its downstream signaling pathways in rheumatoid arthritis.
2. Etanercept (Enbrel): A soluble TNF receptor p75 Fc fusion protein that binds to tumor necrosis factor-alpha (TNF-α) and inhibits its proinflammatory activity, making it a valuable therapeutic option for treating autoimmune diseases like rheumatoid arthritis, ankylosing spondylitis, and psoriasis.
3. Abatacept (Orencia): A fusion protein consisting of the extracellular domain of cytotoxic T-lymphocyte antigen 4 (CTLA-4) linked to the Fc region of an immunoglobulin, which downregulates T-cell activation and proliferation in autoimmune diseases like rheumatoid arthritis.
4. Belimumab (Benlysta): A monoclonal antibody that targets B-lymphocyte stimulator (BLyS) protein, preventing its interaction with the B-cell surface receptor and inhibiting B-cell activation in systemic lupus erythematosus (SLE).
5. Romiplostim (Nplate): A fusion protein consisting of a thrombopoietin receptor agonist peptide linked to an immunoglobulin Fc region, which stimulates platelet production in patients with chronic immune thrombocytopenia (ITP).
6. Darbepoetin alfa (Aranesp): A hyperglycosylated erythropoiesis-stimulating protein that functions as a longer-acting form of recombinant human erythropoietin, used to treat anemia in patients with chronic kidney disease or cancer.
7. Palivizumab (Synagis): A monoclonal antibody directed against the F protein of respiratory syncytial virus (RSV), which prevents RSV infection and is administered prophylactically to high-risk infants during the RSV season.
8. Ranibizumab (Lucentis): A recombinant humanized monoclonal antibody fragment that binds and inhibits vascular endothelial growth factor A (VEGF-A), used in the treatment of age-related macular degeneration, diabetic retinopathy, and other ocular disorders.
9. Cetuximab (Erbitux): A chimeric monoclonal antibody that binds to epidermal growth factor receptor (EGFR), used in the treatment of colorectal cancer and head and neck squamous cell carcinoma.
10. Adalimumab (Humira): A fully humanized monoclonal antibody that targets tumor necrosis factor-alpha (TNF-α), used in the treatment of various inflammatory diseases, including rheumatoid arthritis, psoriasis, and Crohn's disease.
11. Bevacizumab (Avastin): A recombinant humanized monoclonal antibody that binds to VEGF-A, used in the treatment of various cancers, including colorectal, lung, breast, and kidney cancer.
12. Trastuzumab (Herceptin): A humanized monoclonal antibody that targets HER2/neu receptor, used in the treatment of breast cancer.
13. Rituximab (Rituxan): A chimeric monoclonal antibody that binds to CD20 antigen on B cells, used in the treatment of non-Hodgkin's lymphoma and rheumatoid arthritis.
14. Palivizumab (Synagis): A humanized monoclonal antibody that binds to the F protein of respiratory syncytial virus, used in the prevention of respiratory syncytial virus infection in high-risk infants.
15. Infliximab (Remicade): A chimeric monoclonal antibody that targets TNF-α, used in the treatment of various inflammatory diseases, including Crohn's disease, ulcerative colitis, rheumatoid arthritis, and ankylosing spondylitis.
16. Natalizumab (Tysabri): A humanized monoclonal antibody that binds to α4β1 integrin, used in the treatment of multiple sclerosis and Crohn's disease.
17. Adalimumab (Humira): A fully human monoclonal antibody that targets TNF-α, used in the treatment of various inflammatory diseases, including rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, Crohn's disease, and ulcerative colitis.
18. Golimumab (Simponi): A fully human monoclonal antibody that targets TNF-α, used in the treatment of rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, and ulcerative colitis.
19. Certolizumab pegol (Cimzia): A PEGylated Fab' fragment of a humanized monoclonal antibody that targets TNF-α, used in the treatment of rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, and Crohn's disease.
20. Ustekinumab (Stelara): A fully human monoclonal antibody that targets IL-12 and IL-23, used in the treatment of psoriasis, psoriatic arthritis, and Crohn's disease.
21. Secukinumab (Cosentyx): A fully human monoclonal antibody that targets IL-17A, used in the treatment of psoriasis, psoriatic arthritis, and ankylosing spondylitis.
22. Ixekizumab (Taltz): A fully human monoclonal antibody that targets IL-17A, used in the treatment of psoriasis and psoriatic arthritis.
23. Brodalumab (Siliq): A fully human monoclonal antibody that targets IL-17 receptor A, used in the treatment of psoriasis.
24. Sarilumab (Kevzara): A fully human monoclonal antibody that targets the IL-6 receptor, used in the treatment of rheumatoid arthritis.
25. Tocilizumab (Actemra): A humanized monoclonal antibody that targets the IL-6 receptor, used in the treatment of rheumatoid arthritis, systemic juvenile idiopathic arthritis, polyarticular juvenile idiopathic arthritis, giant cell arteritis, and chimeric antigen receptor T-cell-induced cytokine release syndrome.
26. Siltuximab (Sylvant): A chimeric monoclonal antibody that targets IL-6, used in the treatment of multicentric Castleman disease.
27. Satralizumab (Enspryng): A humanized monoclonal antibody that targets IL-6 receptor alpha, used in the treatment of neuromyelitis optica spectrum disorder.
28. Sirukumab (Plivensia): A human monoclonal antibody that targets IL-6, used in the treatment

Immunoblotting, also known as western blotting, is a laboratory technique used in molecular biology and immunogenetics to detect and quantify specific proteins in a complex mixture. This technique combines the electrophoretic separation of proteins by gel electrophoresis with their detection using antibodies that recognize specific epitopes (protein fragments) on the target protein.

The process involves several steps: first, the protein sample is separated based on size through sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Next, the separated proteins are transferred onto a nitrocellulose or polyvinylidene fluoride (PVDF) membrane using an electric field. The membrane is then blocked with a blocking agent to prevent non-specific binding of antibodies.

After blocking, the membrane is incubated with a primary antibody that specifically recognizes the target protein. Following this, the membrane is washed to remove unbound primary antibodies and then incubated with a secondary antibody conjugated to an enzyme such as horseradish peroxidase (HRP) or alkaline phosphatase (AP). The enzyme catalyzes a colorimetric or chemiluminescent reaction that allows for the detection of the target protein.

Immunoblotting is widely used in research and clinical settings to study protein expression, post-translational modifications, protein-protein interactions, and disease biomarkers. It provides high specificity and sensitivity, making it a valuable tool for identifying and quantifying proteins in various biological samples.

Protein-kinase B, also known as AKT, is a group of intracellular proteins that play a crucial role in various cellular processes such as glucose metabolism, apoptosis, cell proliferation, transcription, and cell migration. The AKT family includes three isoforms: AKT1, AKT2, and AKT3, which are encoded by the genes PKBalpha, PKBbeta, and PKBgamma, respectively.

Proto-oncogene proteins c-AKT refer to the normal, non-mutated forms of these proteins that are involved in the regulation of cell growth and survival under physiological conditions. However, when these genes are mutated or overexpressed, they can become oncogenes, leading to uncontrolled cell growth and cancer development.

Activation of c-AKT occurs through a signaling cascade that begins with the binding of extracellular ligands such as insulin-like growth factor 1 (IGF-1) or epidermal growth factor (EGF) to their respective receptors on the cell surface. This triggers a series of phosphorylation events that ultimately lead to the activation of c-AKT, which then phosphorylates downstream targets involved in various cellular processes.

In summary, proto-oncogene proteins c-AKT are normal intracellular proteins that play essential roles in regulating cell growth and survival under physiological conditions. However, their dysregulation can contribute to cancer development and progression.

A precipitin test is a type of immunodiagnostic test used to detect and measure the presence of specific antibodies or antigens in a patient's serum. The test is based on the principle of antigen-antibody interaction, where the addition of an antigen to a solution containing its corresponding antibody results in the formation of an insoluble immune complex known as a precipitin.

In this test, a small amount of the patient's serum is added to a solution containing a known antigen or antibody. If the patient has antibodies or antigens that correspond to the added reagent, they will bind and form a visible precipitate. The size and density of the precipitate can be used to quantify the amount of antibody or antigen present in the sample.

Precipitin tests are commonly used in the diagnosis of various infectious diseases, autoimmune disorders, and allergies. They can also be used in forensic science to identify biological samples. However, they have largely been replaced by more modern immunological techniques such as enzyme-linked immunosorbent assays (ELISAs) and radioimmunoassays (RIAs).

DNA primers are short single-stranded DNA molecules that serve as a starting point for DNA synthesis. They are typically used in laboratory techniques such as the polymerase chain reaction (PCR) and DNA sequencing. The primer binds to a complementary sequence on the DNA template through base pairing, providing a free 3'-hydroxyl group for the DNA polymerase enzyme to add nucleotides and synthesize a new strand of DNA. This allows for specific and targeted amplification or analysis of a particular region of interest within a larger DNA molecule.

Protein kinases are a group of enzymes that play a crucial role in many cellular processes by adding phosphate groups to other proteins, a process known as phosphorylation. This modification can activate or deactivate the target protein's function, thereby regulating various signaling pathways within the cell. Protein kinases are essential for numerous biological functions, including metabolism, signal transduction, cell cycle progression, and apoptosis (programmed cell death). Abnormal regulation of protein kinases has been implicated in several diseases, such as cancer, diabetes, and neurological disorders.

An amino acid sequence is the specific order of amino acids in a protein or peptide molecule, formed by the linking of the amino group (-NH2) of one amino acid to the carboxyl group (-COOH) of another amino acid through a peptide bond. The sequence is determined by the genetic code and is unique to each type of protein or peptide. It plays a crucial role in determining the three-dimensional structure and function of proteins.

RNA interference (RNAi) is a biological process in which RNA molecules inhibit the expression of specific genes. This process is mediated by small RNA molecules, including microRNAs (miRNAs) and small interfering RNAs (siRNAs), that bind to complementary sequences on messenger RNA (mRNA) molecules, leading to their degradation or translation inhibition.

RNAi plays a crucial role in regulating gene expression and defending against foreign genetic elements, such as viruses and transposons. It has also emerged as an important tool for studying gene function and developing therapeutic strategies for various diseases, including cancer and viral infections.

Cell differentiation is the process by which a less specialized cell, or stem cell, becomes a more specialized cell type with specific functions and structures. This process involves changes in gene expression, which are regulated by various intracellular signaling pathways and transcription factors. Differentiation results in the development of distinct cell types that make up tissues and organs in multicellular organisms. It is a crucial aspect of embryonic development, tissue repair, and maintenance of homeostasis in the body.

Epithelial cells are types of cells that cover the outer surfaces of the body, line the inner surfaces of organs and glands, and form the lining of blood vessels and body cavities. They provide a protective barrier against the external environment, regulate the movement of materials between the internal and external environments, and are involved in the sense of touch, temperature, and pain. Epithelial cells can be squamous (flat and thin), cuboidal (square-shaped and of equal height), or columnar (tall and narrow) in shape and are classified based on their location and function.

Transcriptional activation is the process by which a cell increases the rate of transcription of specific genes from DNA to RNA. This process is tightly regulated and plays a crucial role in various biological processes, including development, differentiation, and response to environmental stimuli.

Transcriptional activation occurs when transcription factors (proteins that bind to specific DNA sequences) interact with the promoter region of a gene and recruit co-activator proteins. These co-activators help to remodel the chromatin structure around the gene, making it more accessible for the transcription machinery to bind and initiate transcription.

Transcriptional activation can be regulated at multiple levels, including the availability and activity of transcription factors, the modification of histone proteins, and the recruitment of co-activators or co-repressors. Dysregulation of transcriptional activation has been implicated in various diseases, including cancer and genetic disorders.

Medical Definition:
Microtubule-associated proteins (MAPs) are a diverse group of proteins that bind to microtubules, which are key components of the cytoskeleton in eukaryotic cells. MAPs play crucial roles in regulating microtubule dynamics and stability, as well as in mediating interactions between microtubules and other cellular structures. They can be classified into several categories based on their functions, including:

1. Microtubule stabilizers: These MAPs promote the assembly of microtubules and protect them from disassembly by enhancing their stability. Examples include tau proteins and MAP2.
2. Microtubule dynamics regulators: These MAPs modulate the rate of microtubule polymerization and depolymerization, allowing for dynamic reorganization of the cytoskeleton during cell division and other processes. Examples include stathmin and XMAP215.
3. Microtubule motor proteins: These MAPs use energy from ATP hydrolysis to move along microtubules, transporting various cargoes within the cell. Examples include kinesin and dynein.
4. Adapter proteins: These MAPs facilitate interactions between microtubules and other cellular structures, such as membranes, organelles, or signaling molecules. Examples include MAP4 and CLASPs.

Dysregulation of MAPs has been implicated in several diseases, including neurodegenerative disorders like Alzheimer's disease (where tau proteins form abnormal aggregates called neurofibrillary tangles) and cancer (where altered microtubule dynamics can contribute to uncontrolled cell division).

Human chromosome pair 14 consists of two rod-shaped structures present in the nucleus of human cells, which contain genetic material in the form of DNA and proteins. Each member of the pair contains a single very long DNA molecule that carries an identical set of genes and other genetic elements, totaling approximately 105 million base pairs. These chromosomes play a crucial role in the development, functioning, and reproduction of human beings.

Chromosome 14 is one of the autosomal chromosomes, meaning it is not involved in determining the sex of an individual. It contains around 800-1,000 genes that provide instructions for producing various proteins responsible for numerous cellular functions and processes. Some notable genes located on chromosome 14 include those associated with neurodevelopmental disorders, cancer susceptibility, and immune system regulation.

Human cells typically have 23 pairs of chromosomes, including 22 autosomal pairs (numbered 1-22) and one pair of sex chromosomes (XX for females or XY for males). Chromosome pair 14 is the eighth largest autosomal pair in terms of its total length.

It's important to note that genetic information on chromosome 14, like all human chromosomes, can vary between individuals due to genetic variations and mutations. These differences contribute to the unique characteristics and traits found among humans.

Mammary glands are specialized exocrine glands found in mammals, including humans and other animals. These glands are responsible for producing milk, which is used to nurse offspring after birth. The mammary glands are located in the breast region of female mammals and are usually rudimentary or absent in males.

In animals, mammary glands can vary in number and location depending on the species. For example, humans and other primates have two mammary glands, one in each breast. Cows, goats, and sheep, on the other hand, have multiple pairs of mammary glands located in their lower abdominal region.

Mammary glands are made up of several structures, including lobules, ducts, and connective tissue. The lobules contain clusters of milk-secreting cells called alveoli, which produce and store milk. The ducts transport the milk from the lobules to the nipple, where it is released during lactation.

Mammary glands are an essential feature of mammals, as they provide a source of nutrition for newborn offspring. They also play a role in the development and maintenance of the mother-infant bond, as nursing provides opportunities for physical contact and bonding between the mother and her young.

Biological models, also known as physiological models or organismal models, are simplified representations of biological systems, processes, or mechanisms that are used to understand and explain the underlying principles and relationships. These models can be theoretical (conceptual or mathematical) or physical (such as anatomical models, cell cultures, or animal models). They are widely used in biomedical research to study various phenomena, including disease pathophysiology, drug action, and therapeutic interventions.

Examples of biological models include:

1. Mathematical models: These use mathematical equations and formulas to describe complex biological systems or processes, such as population dynamics, metabolic pathways, or gene regulation networks. They can help predict the behavior of these systems under different conditions and test hypotheses about their underlying mechanisms.
2. Cell cultures: These are collections of cells grown in a controlled environment, typically in a laboratory dish or flask. They can be used to study cellular processes, such as signal transduction, gene expression, or metabolism, and to test the effects of drugs or other treatments on these processes.
3. Animal models: These are living organisms, usually vertebrates like mice, rats, or non-human primates, that are used to study various aspects of human biology and disease. They can provide valuable insights into the pathophysiology of diseases, the mechanisms of drug action, and the safety and efficacy of new therapies.
4. Anatomical models: These are physical representations of biological structures or systems, such as plastic models of organs or tissues, that can be used for educational purposes or to plan surgical procedures. They can also serve as a basis for developing more sophisticated models, such as computer simulations or 3D-printed replicas.

Overall, biological models play a crucial role in advancing our understanding of biology and medicine, helping to identify new targets for therapeutic intervention, develop novel drugs and treatments, and improve human health.

I'm sorry for any confusion, but "Protamine Kinase" is not a widely recognized or established term in medical or biological sciences. Protamines are small, arginine-rich proteins found in the sperm cells of many organisms, and they play a crucial role in the packaging and protection of DNA during spermatogenesis.

Kinases, on the other hand, are enzymes that catalyze the transfer of phosphate groups from ATP to specific amino acids in proteins, thereby modulating their function, localization, or stability.

A search of scientific literature reveals only a few instances where "protamine kinase" is mentioned, usually in the context of potential regulatory mechanisms during sperm maturation or fertilization. However, there is no widely accepted or well-characterized enzyme known as "protamine kinase." Therefore, it would be challenging to provide a concise and accurate medical definition for this term.

Carrier proteins, also known as transport proteins, are a type of protein that facilitates the movement of molecules across cell membranes. They are responsible for the selective and active transport of ions, sugars, amino acids, and other molecules from one side of the membrane to the other, against their concentration gradient. This process requires energy, usually in the form of ATP (adenosine triphosphate).

Carrier proteins have a specific binding site for the molecule they transport, and undergo conformational changes upon binding, which allows them to move the molecule across the membrane. Once the molecule has been transported, the carrier protein returns to its original conformation, ready to bind and transport another molecule.

Carrier proteins play a crucial role in maintaining the balance of ions and other molecules inside and outside of cells, and are essential for many physiological processes, including nerve impulse transmission, muscle contraction, and nutrient uptake.

Cyclin-dependent kinase inhibitor proteins (CDKIs) are a family of regulatory proteins that play a crucial role in the control of the cell cycle. They function by binding to and inhibiting the activity of cyclin-dependent kinases (CDKs), which are serine/threonine protein kinases that help drive the progression of the cell cycle.

There are two main families of CDKIs: the Ink4 family and the Cip/Kip family. The Ink4 family members, including p16INK4a, p15INK4b, p18INK4c, and p19INK4d, specifically inhibit CDK4 and CDK6, preventing their association with cyclin D and thus blocking the transition from G1 to S phase of the cell cycle. The Cip/Kip family members, including p21CIP1, p27KIP1, and p57KIP2, inhibit a broader range of CDKs, including CDK1, CDK2, CDK4, and CDK6, and can regulate multiple stages of the cell cycle.

CDKIs play important roles in various biological processes, such as cell growth, differentiation, and apoptosis. Dysregulation of CDKI function has been implicated in several human diseases, including cancer, where loss or mutation of CDKIs can lead to uncontrolled cell proliferation and tumorigenesis. Therefore, CDKIs are attractive targets for the development of anti-cancer therapies.

Threonine is an essential amino acid, meaning it cannot be synthesized by the human body and must be obtained through the diet. Its chemical formula is HO2CCH(NH2)CH(OH)CH3. Threonine plays a crucial role in various biological processes, including protein synthesis, immune function, and fat metabolism. It is particularly important for maintaining the structural integrity of proteins, as it is often found in their hydroxyl-containing regions. Foods rich in threonine include animal proteins such as meat, dairy products, and eggs, as well as plant-based sources like lentils and soybeans.

Squamous cell carcinoma is a type of skin cancer that begins in the squamous cells, which are flat, thin cells that form the outer layer of the skin (epidermis). It commonly occurs on sun-exposed areas such as the face, ears, lips, and backs of the hands. Squamous cell carcinoma can also develop in other areas of the body including the mouth, lungs, and cervix.

This type of cancer usually develops slowly and may appear as a rough or scaly patch of skin, a red, firm nodule, or a sore or ulcer that doesn't heal. While squamous cell carcinoma is not as aggressive as some other types of cancer, it can metastasize (spread) to other parts of the body if left untreated, making early detection and treatment important.

Risk factors for developing squamous cell carcinoma include prolonged exposure to ultraviolet (UV) radiation from the sun or tanning beds, fair skin, a history of sunburns, a weakened immune system, and older age. Prevention measures include protecting your skin from the sun by wearing protective clothing, using a broad-spectrum sunscreen with an SPF of at least 30, avoiding tanning beds, and getting regular skin examinations.

The G1 phase cell cycle checkpoint is a point in the cell cycle where the cell checks and regulates its progression from the G1 phase to the S phase. During this checkpoint, the cell evaluates various factors such as availability of nutrients, growth factors, and the absence of DNA damage to determine whether it should proceed with DNA replication or undergo cellular senescence, differentiation, or apoptosis (programmed cell death). The G1 phase checkpoint is controlled by a complex network of signaling pathways, including the p53 and Rb tumor suppressor proteins.

Antineoplastic agents are a class of drugs used to treat malignant neoplasms or cancer. These agents work by inhibiting the growth and proliferation of cancer cells, either by killing them or preventing their division and replication. Antineoplastic agents can be classified based on their mechanism of action, such as alkylating agents, antimetabolites, topoisomerase inhibitors, mitotic inhibitors, and targeted therapy agents.

Alkylating agents work by adding alkyl groups to DNA, which can cause cross-linking of DNA strands and ultimately lead to cell death. Antimetabolites interfere with the metabolic processes necessary for DNA synthesis and replication, while topoisomerase inhibitors prevent the relaxation of supercoiled DNA during replication. Mitotic inhibitors disrupt the normal functioning of the mitotic spindle, which is essential for cell division. Targeted therapy agents are designed to target specific molecular abnormalities in cancer cells, such as mutated oncogenes or dysregulated signaling pathways.

It's important to note that antineoplastic agents can also affect normal cells and tissues, leading to various side effects such as nausea, vomiting, hair loss, and myelosuppression (suppression of bone marrow function). Therefore, the use of these drugs requires careful monitoring and management of their potential adverse effects.

Phosphatidylinositol 3-Kinases (PI3Ks) are a family of enzymes that play a crucial role in intracellular signal transduction. They phosphorylate the 3-hydroxyl group of the inositol ring in phosphatidylinositol and its derivatives, which results in the production of second messengers that regulate various cellular processes such as cell growth, proliferation, differentiation, motility, and survival.

PI3Ks are divided into three classes based on their structure and substrate specificity. Class I PI3Ks are further subdivided into two categories: class IA and class IB. Class IA PI3Ks are heterodimers consisting of a catalytic subunit (p110α, p110β, or p110δ) and a regulatory subunit (p85α, p85β, p55γ, or p50γ). They are primarily activated by receptor tyrosine kinases and G protein-coupled receptors. Class IB PI3Ks consist of a catalytic subunit (p110γ) and a regulatory subunit (p101 or p84/87). They are mainly activated by G protein-coupled receptors.

Dysregulation of PI3K signaling has been implicated in various human diseases, including cancer, diabetes, and autoimmune disorders. Therefore, PI3Ks have emerged as important targets for drug development in these areas.

Maturation-Promoting Factor (MPF) is not a medical term per se, but it is commonly used in the field of cell biology and cancer research. MPF refers to a complex of two proteins that play a crucial role in regulating the cell cycle, specifically during the transition from the G2 phase to mitosis (M phase).

MPF is composed of a cyclin-dependent kinase (CDK1) and a regulatory subunit called cyclin B. During the late G2 phase, the levels of cyclin B increase, which leads to the activation of CDK1. Once activated, MPF triggers a series of events that promote mitosis, including chromosome condensation, nuclear envelope breakdown, and spindle formation.

In summary, Maturation-Promoting Factor (MPF) is a protein complex made up of CDK1 and cyclin B, which regulates the transition from the G2 phase to mitosis during the cell cycle.

Mitogen-Activated Protein Kinases (MAPKs) are a family of serine/threonine protein kinases that play crucial roles in various cellular processes, including proliferation, differentiation, transformation, and apoptosis, in response to diverse stimuli such as mitogens, growth factors, hormones, cytokines, and environmental stresses. They are highly conserved across eukaryotes and consist of a three-tiered kinase module composed of MAPK kinase kinases (MAP3Ks), MAPK kinases (MKKs or MAP2Ks), and MAPKs.

Activation of MAPKs occurs through a sequential phosphorylation and activation cascade, where MAP3Ks phosphorylate and activate MKKs, which in turn phosphorylate and activate MAPKs at specific residues (Thr-X-Tyr or Ser-Pro motifs). Once activated, MAPKs can further phosphorylate and regulate various downstream targets, including transcription factors and other protein kinases.

There are four major groups of MAPKs in mammals: extracellular signal-regulated kinases (ERK1/2), c-Jun N-terminal kinases (JNK1/2/3), p38 MAPKs (p38α/β/γ/δ), and ERK5/BMK1. Each group of MAPKs has distinct upstream activators, downstream targets, and cellular functions, allowing for a high degree of specificity in signal transduction and cellular responses. Dysregulation of MAPK signaling pathways has been implicated in various human diseases, including cancer, diabetes, neurodegenerative disorders, and inflammatory diseases.

A "knockout" mouse is a genetically engineered mouse in which one or more genes have been deleted or "knocked out" using molecular biology techniques. This allows researchers to study the function of specific genes and their role in various biological processes, as well as potential associations with human diseases. The mice are generated by introducing targeted DNA modifications into embryonic stem cells, which are then used to create a live animal. Knockout mice have been widely used in biomedical research to investigate gene function, disease mechanisms, and potential therapeutic targets.

Luciferases are a class of enzymes that catalyze the oxidation of their substrates, leading to the emission of light. This bioluminescent process is often associated with certain species of bacteria, insects, and fish. The term "luciferase" comes from the Latin word "lucifer," which means "light bearer."

The most well-known example of luciferase is probably that found in fireflies, where the enzyme reacts with a compound called luciferin to produce light. This reaction requires the presence of oxygen and ATP (adenosine triphosphate), which provides the energy needed for the reaction to occur.

Luciferases have important applications in scientific research, particularly in the development of sensitive assays for detecting gene expression and protein-protein interactions. By labeling a protein or gene of interest with luciferase, researchers can measure its activity by detecting the light emitted during the enzymatic reaction. This allows for highly sensitive and specific measurements, making luciferases valuable tools in molecular biology and biochemistry.

Deoxyribonucleic acid (DNA) is the genetic material present in the cells of organisms where it is responsible for the storage and transmission of hereditary information. DNA is a long molecule that consists of two strands coiled together to form a double helix. Each strand is made up of a series of four nucleotide bases - adenine (A), guanine (G), cytosine (C), and thymine (T) - that are linked together by phosphate and sugar groups. The sequence of these bases along the length of the molecule encodes genetic information, with A always pairing with T and C always pairing with G. This base-pairing allows for the replication and transcription of DNA, which are essential processes in the functioning and reproduction of all living organisms.

I'm sorry for any confusion, but "Genes, myc" is not a recognized medical term or abbreviation. It seems like there might be a misunderstanding or a missing word in the request. "Myc" could refer to the Myc family of transcription factors that are involved in cell growth and division, and are often deregulated in cancer. However, without more context, it's difficult to provide an accurate definition. If you could provide more information or clarify your question, I would be happy to help further!

Immunoprecipitation (IP) is a research technique used in molecular biology and immunology to isolate specific antigens or antibodies from a mixture. It involves the use of an antibody that recognizes and binds to a specific antigen, which is then precipitated out of solution using various methods, such as centrifugation or chemical cross-linking.

In this technique, an antibody is first incubated with a sample containing the antigen of interest. The antibody specifically binds to the antigen, forming an immune complex. This complex can then be captured by adding protein A or G agarose beads, which bind to the constant region of the antibody. The beads are then washed to remove any unbound proteins, leaving behind the precipitated antigen-antibody complex.

Immunoprecipitation is a powerful tool for studying protein-protein interactions, post-translational modifications, and signal transduction pathways. It can also be used to detect and quantify specific proteins in biological samples, such as cells or tissues, and to identify potential biomarkers of disease.

"Nude mice" is a term used in the field of laboratory research to describe a strain of mice that have been genetically engineered to lack a functional immune system. Specifically, nude mice lack a thymus gland and have a mutation in the FOXN1 gene, which results in a failure to develop a mature T-cell population. This means that they are unable to mount an effective immune response against foreign substances or organisms.

The name "nude" refers to the fact that these mice also have a lack of functional hair follicles, resulting in a hairless or partially hairless phenotype. This feature is actually a secondary consequence of the same genetic mutation that causes their immune deficiency.

Nude mice are commonly used in research because their weakened immune system makes them an ideal host for transplanted tumors, tissues, and cells from other species, including humans. This allows researchers to study the behavior of these foreign substances in a living organism without the complication of an immune response. However, it's important to note that because nude mice lack a functional immune system, they must be kept in sterile conditions and are more susceptible to infection than normal mice.

Cell growth processes refer to the series of events that occur within a cell leading to an increase in its size, mass, and number of organelles. These processes are essential for the development, maintenance, and reproduction of all living organisms. The main cell growth processes include:

1. Cell Cycle: It is the sequence of events that a eukaryotic cell goes through from one cell division (mitosis) to the next. The cell cycle consists of four distinct phases: G1 phase (growth and preparation for DNA replication), S phase (DNA synthesis), G2 phase (preparation for mitosis), and M phase (mitosis or meiosis).

2. DNA Replication: It is the process by which a cell makes an identical copy of its DNA molecule before cell division. This ensures that each daughter cell receives an exact replica of the parent cell's genetic material.

3. Protein Synthesis: Cells grow by increasing their protein content, which is achieved through the process of protein synthesis. This involves transcribing DNA into mRNA (transcription) and then translating that mRNA into a specific protein sequence (translation).

4. Cellular Metabolism: It refers to the sum total of all chemical reactions that occur within a cell to maintain life. These reactions include catabolic processes, which break down nutrients to release energy, and anabolic processes, which use energy to build complex molecules like proteins, lipids, and carbohydrates.

5. Cell Signaling: Cells communicate with each other through intricate signaling pathways that help coordinate growth, differentiation, and survival. These signals can come from within the cell (intracellular) or from outside the cell (extracellular).

6. Cell Division: Also known as mitosis, it is the process by which a single cell divides into two identical daughter cells. This ensures that each new cell contains an exact copy of the parent cell's genetic material and allows for growth and repair of tissues.

7. Apoptosis: It is a programmed cell death process that helps maintain tissue homeostasis by eliminating damaged or unnecessary cells. Dysregulation of apoptosis can lead to diseases such as cancer and autoimmune disorders.

I'm sorry for any confusion, but "Active Transport, Cell Nucleus" is not a widely recognized or established medical term. Active transport typically refers to the energy-dependent process by which cells move molecules across their membranes against their concentration gradient. This process is facilitated by transport proteins and requires ATP as an energy source. However, this process primarily occurs in the cell membrane and not in the cell nucleus.

The cell nucleus, on the other hand, contains genetic material (DNA) and is responsible for controlling various cellular activities such as gene expression, replication, and repair. While there are transport processes that occur within the nucleus, they do not typically involve active transport in the same way that it occurs at the cell membrane.

Therefore, a medical definition of "Active Transport, Cell Nucleus" would not be applicable or informative in this context.

Cyclin-Dependent Kinase 9 (CDK9) is a type of serine/threonine protein kinase that plays a crucial role in the regulation of transcription. It forms a complex with cyclin T1, K or H and gets activated by phosphorylation. This complex, known as P-TEFb, is involved in the phosphorylation and activation of the C-terminal domain of RNA polymerase II, which is essential for the transcription elongation of most protein-coding genes. CDK9 also regulates other cellular processes such as apoptosis, differentiation, and cell cycle progression. Dysregulation of CDK9 has been implicated in various diseases including cancer.

Bromodeoxyuridine (BrdU) is a synthetic thymidine analog that can be incorporated into DNA during cell replication. It is often used in research and medical settings as a marker for cell proliferation or as a tool to investigate DNA synthesis and repair. When cells are labeled with BrdU and then examined using immunofluorescence or other detection techniques, the presence of BrdU can indicate which cells have recently divided or are actively synthesizing DNA.

In medical contexts, BrdU has been used in cancer research to study tumor growth and response to treatment. It has also been explored as a potential therapeutic agent for certain conditions, such as neurodegenerative diseases, where promoting cell proliferation and replacement of damaged cells may be beneficial. However, its use as a therapeutic agent is still experimental and requires further investigation.

Ubiquitin is a small protein that is present in most tissues in the body. It plays a critical role in regulating many important cellular processes, such as protein degradation and DNA repair. Ubiquitin can attach to other proteins in a process called ubiquitination, which can target the protein for degradation or modify its function.

Ubiquitination involves a series of enzymatic reactions that ultimately result in the attachment of ubiquitin molecules to specific lysine residues on the target protein. The addition of a single ubiquitin molecule is called monoubiquitination, while the addition of multiple ubiquitin molecules is called polyubiquitination.

Polyubiquitination can serve as a signal for proteasomal degradation, where the target protein is broken down into its component amino acids by the 26S proteasome complex. Monoubiquitination and other forms of ubiquitination can also regulate various cellular processes, such as endocytosis, DNA repair, and gene expression.

Dysregulation of ubiquitin-mediated protein degradation has been implicated in a variety of diseases, including cancer, neurodegenerative disorders, and inflammatory conditions.

Cytoplasm is the material within a eukaryotic cell (a cell with a true nucleus) that lies between the nuclear membrane and the cell membrane. It is composed of an aqueous solution called cytosol, in which various organelles such as mitochondria, ribosomes, endoplasmic reticulum, Golgi apparatus, lysosomes, and vacuoles are suspended. Cytoplasm also contains a variety of dissolved nutrients, metabolites, ions, and enzymes that are involved in various cellular processes such as metabolism, signaling, and transport. It is where most of the cell's metabolic activities take place, and it plays a crucial role in maintaining the structure and function of the cell.

I believe you may be mistakenly using the term "starfish" to refer to a medical condition. If so, the correct term is likely " asterixis," which is a medical sign characterized by rapid, rhythmic flapping or tremulous movements of the hands when they are extended and the wrist is dorsiflexed (held with the back of the hand facing upwards). This is often seen in people with certain neurological conditions such as liver failure or certain types of poisoning.

However, if you are indeed referring to the marine animal commonly known as a "starfish," there isn't a specific medical definition for it. Starfish, also known as sea stars, are marine animals belonging to the class Asteroidea in the phylum Echinodermata. They have a distinctive shape with five or more arms radiating from a central disc, and they move slowly along the ocean floor using their tube feet. Some species of starfish have the ability to regenerate lost body parts, including entire limbs or even their central disc.

Gene amplification is a process in molecular biology where a specific gene or set of genes are copied multiple times, leading to an increased number of copies of that gene within the genome. This can occur naturally in cells as a response to various stimuli, such as stress or exposure to certain chemicals, but it can also be induced artificially through laboratory techniques for research purposes.

In cancer biology, gene amplification is often associated with tumor development and progression, where the amplified genes can contribute to increased cell growth, survival, and drug resistance. For example, the overamplification of the HER2/neu gene in breast cancer has been linked to more aggressive tumors and poorer patient outcomes.

In diagnostic and research settings, gene amplification techniques like polymerase chain reaction (PCR) are commonly used to detect and analyze specific genes or genetic sequences of interest. These methods allow researchers to quickly and efficiently generate many copies of a particular DNA sequence, facilitating downstream analysis and detection of low-abundance targets.

DNA replication is the biological process by which DNA makes an identical copy of itself during cell division. It is a fundamental mechanism that allows genetic information to be passed down from one generation of cells to the next. During DNA replication, each strand of the double helix serves as a template for the synthesis of a new complementary strand. This results in the creation of two identical DNA molecules. The enzymes responsible for DNA replication include helicase, which unwinds the double helix, and polymerase, which adds nucleotides to the growing strands.

E2F4 is a member of the E2F family of transcription factors, which are involved in the regulation of cell cycle progression and differentiation. E2F4 can function as both a transcriptional activator and repressor, depending on which proteins it interacts with. It primarily acts as a repressor, binding to DNA and preventing the transcription of target genes involved in cell cycle progression. E2F4 has been shown to play important roles in various biological processes, including development, differentiation, and tumor suppression.

Ubiquitin-Protein Ligase Complexes, also known as E3 ubiquitin ligases, are a group of enzymes that play a crucial role in the ubiquitination process. Ubiquitination is a post-translational modification where ubiquitin molecules are attached to specific target proteins, marking them for degradation by the proteasome or altering their function, localization, or interaction with other proteins.

The ubiquitination process involves three main steps:

1. Ubiquitin activation: Ubiquitin is activated by an E1 ubiquitin-activating enzyme in an ATP-dependent reaction.
2. Ubiquitin conjugation: The activated ubiquitin is then transferred to an E2 ubiquitin-conjugating enzyme.
3. Ubiquitin ligation: Finally, the E2 ubiquitin-conjugating enzyme interacts with a specific E3 ubiquitin ligase complex, which facilitates the transfer and ligation of ubiquitin to the target protein.

Ubiquitin-Protein Ligase Complexes are responsible for recognizing and binding to specific substrate proteins, ensuring that ubiquitination occurs on the correct targets. They can be divided into three main categories based on their structural features and mechanisms of action:

1. Really Interesting New Gene (RING) finger E3 ligases: These E3 ligases contain a RING finger domain, which directly interacts with both the E2 ubiquitin-conjugating enzyme and the substrate protein. They facilitate the transfer of ubiquitin from the E2 to the target protein by bringing them into close proximity.
2. Homologous to E6-AP C terminus (HECT) E3 ligases: These E3 ligases contain a HECT domain, which interacts with the E2 ubiquitin-conjugating enzyme and forms a thioester bond with ubiquitin before transferring it to the substrate protein.
3. RING-between-RING (RBR) E3 ligases: These E3 ligases contain both RING finger and HECT-like domains, which allow them to function similarly to both RING finger and HECT E3 ligases. They first form a thioester bond with ubiquitin using their RING1 domain before transferring it to the substrate protein via their RING2 domain.

Dysregulation of Ubiquitin-Protein Ligase Complexes has been implicated in various diseases, including cancer and neurodegenerative disorders. Understanding their mechanisms and functions can provide valuable insights into disease pathogenesis and potential therapeutic strategies.

Northern blotting is a laboratory technique used in molecular biology to detect and analyze specific RNA molecules (such as mRNA) in a mixture of total RNA extracted from cells or tissues. This technique is called "Northern" blotting because it is analogous to the Southern blotting method, which is used for DNA detection.

The Northern blotting procedure involves several steps:

1. Electrophoresis: The total RNA mixture is first separated based on size by running it through an agarose gel using electrical current. This separates the RNA molecules according to their length, with smaller RNA fragments migrating faster than larger ones.

2. Transfer: After electrophoresis, the RNA bands are denatured (made single-stranded) and transferred from the gel onto a nitrocellulose or nylon membrane using a technique called capillary transfer or vacuum blotting. This step ensures that the order and relative positions of the RNA fragments are preserved on the membrane, similar to how they appear in the gel.

3. Cross-linking: The RNA is then chemically cross-linked to the membrane using UV light or heat treatment, which helps to immobilize the RNA onto the membrane and prevent it from washing off during subsequent steps.

4. Prehybridization: Before adding the labeled probe, the membrane is prehybridized in a solution containing blocking agents (such as salmon sperm DNA or yeast tRNA) to minimize non-specific binding of the probe to the membrane.

5. Hybridization: A labeled nucleic acid probe, specific to the RNA of interest, is added to the prehybridization solution and allowed to hybridize (form base pairs) with its complementary RNA sequence on the membrane. The probe can be either a DNA or an RNA molecule, and it is typically labeled with a radioactive isotope (such as ³²P) or a non-radioactive label (such as digoxigenin).

6. Washing: After hybridization, the membrane is washed to remove unbound probe and reduce background noise. The washing conditions (temperature, salt concentration, and detergent concentration) are optimized based on the stringency required for specific hybridization.

7. Detection: The presence of the labeled probe is then detected using an appropriate method, depending on the type of label used. For radioactive probes, this typically involves exposing the membrane to X-ray film or a phosphorimager screen and analyzing the resulting image. For non-radioactive probes, detection can be performed using colorimetric, chemiluminescent, or fluorescent methods.

8. Data analysis: The intensity of the signal is quantified and compared to controls (such as housekeeping genes) to determine the relative expression level of the RNA of interest. This information can be used for various purposes, such as identifying differentially expressed genes in response to a specific treatment or comparing gene expression levels across different samples or conditions.

Prognosis is a medical term that refers to the prediction of the likely outcome or course of a disease, including the chances of recovery or recurrence, based on the patient's symptoms, medical history, physical examination, and diagnostic tests. It is an important aspect of clinical decision-making and patient communication, as it helps doctors and patients make informed decisions about treatment options, set realistic expectations, and plan for future care.

Prognosis can be expressed in various ways, such as percentages, categories (e.g., good, fair, poor), or survival rates, depending on the nature of the disease and the available evidence. However, it is important to note that prognosis is not an exact science and may vary depending on individual factors, such as age, overall health status, and response to treatment. Therefore, it should be used as a guide rather than a definitive forecast.

STAT3 (Signal Transducer and Activator of Transcription 3) is a transcription factor protein that plays a crucial role in signal transduction and gene regulation. It is activated through phosphorylation by various cytokines and growth factors, which leads to its dimerization, nuclear translocation, and binding to specific DNA sequences. Once bound to the DNA, STAT3 regulates the expression of target genes involved in various cellular processes such as proliferation, differentiation, survival, and angiogenesis. Dysregulation of STAT3 has been implicated in several diseases, including cancer, autoimmune disorders, and inflammatory conditions.

Brooks AR, Shiffman D, Chan CS, Brooks EE, Milner PG (Apr 1996). "Functional analysis of the human cyclin D2 and cyclin D3 ... Cyclins function as regulators of cyclin-dependent kinases. Different cyclins exhibit distinct expression and degradation ... G1/S-specific cyclin-D2 is a protein that in humans is encoded by the CCND2 gene. The protein encoded by this gene belongs to ... "Entrez Gene: CCND2 cyclin D2". Mirzaa GM, Parry DA, Fry AE, Giamanco KA, Schwartzentruber J, Vanstone M, Logan CV, Roberts N, ...
CDK6; cyclin D1, cyclin D2, cyclin D3 CDK7; cyclin H CDK8; cyclin C CDK9; cyclin T1, cyclin T2a, cyclin T2b, cyclin K CDK10 ... cyclin A, cyclin B CDK2; cyclin A, cyclin E CDK3; cyclin C CDK4; cyclin D1, cyclin D2, cyclin D3 CDK5; CDK5R1, CDK5R2. See also ... Furthermore, cyclin binding determines the specificity of the cyclin-CDK complex for particular substrates. Cyclins can ... Viruses can encode proteins with sequence homology to cyclins. One much-studied example is K-cyclin (or v-cyclin) from Kaposi ...
Brooks AR, Shiffman D, Chan CS, Brooks EE, Milner PG (1996). "Functional analysis of the human cyclin D2 and cyclin D3 ... Cyclin-dependent kinase 4, Cyclin-dependent kinase 6, EIF3K, and Retinoic acid receptor alpha. Cyclin Cyclin D GRCh38: Ensembl ... Cyclins function as regulators of CDK kinases. Different cyclins exhibit distinct expression and degradation patterns which ... G1/S-specific cyclin-D3 is a protein that in humans is encoded by the CCND3 gene. The protein encoded by this gene belongs to ...
This is consistent with the role of Pitx2 in regulating the growth-regulating genes cyclin D2, cyclin D1, and C-Myc. In renal ... promotes thyroid carcinogenesis by activation of cyclin D2". Cell Cycle. 9 (7): 1333-41. doi:10.4161/cc.9.7.11126. PMID ...
CDK6 is positively regulated primarily by its union to the D cyclins D1, D2 and D3. If this subunit of the complex is not ... A Cyclin-dependent kinase 6 interacts with: CDKN2C, Cyclin D1, Cyclin D3, P16, PPM1B, and PPP2CA. Cell cycle Cyclin-dependent ... It is regulated by cyclins, more specifically by Cyclin D proteins and Cyclin-dependent kinase inhibitor proteins. The protein ... In mammalian cells, cell cycle is activated by CDK6 in the early G1 phase through interactions with cyclins D1, D2 and D3. ...
In mice and humans, two more cyclin D proteins have been identified. The three homologues, called cyclin D1, cyclin D2, and ... All six cyclin D-Cdk4,6 complexes (cyclin D1/D2/D3 with Cdk4/6) target Rb for phosphorylation through helix-based docking. The ... Other than Rb, viral cyclin D-Cdk6 complex also targets p27Kip, a Cdk inhibitor of cyclin E and A. In addition, viral cyclin D- ... The phosphorylation of Rb by cyclin A-Cdk2, cyclin B-Cdk1, and cyclin E-Cdk2 are unaffected. The C terminus has a stretch of 21 ...
Tsunekawa, Yuji; Osumi, Noriko (November 2013). "Control of asymmetry distribution and the differentiation fate of Cyclin D2 in ...
... repress cyclin D1 and cyclin D2 promoter activity and encourages cell cycle arrest at cyclin G1 (CCNG1). As a result of that, ... Furthermore, FOXO1-mediated cell cycle arrest is linked with cyclin D1 and cyclin D2 suppression in mammals. It was detected ... The transcription and half- life of cyclin-dependent kinase inhibitor p27KIP1 rises when FOXO1 is active. A study detects that ... activation of FOXO1 prevents the cell-division cycle at cyclin G1 (CCNG1) out of one of two ways stimulating or suppressing ...
... "miR-497 and miR-302b regulate ethanol-induced neuronal cell death through BCL2 protein and cyclin D2". The Journal of ...
... A also raises cyclin D2 levels suggesting a role for the latter in macrophage activation besides proliferation. It ...
Other reported downstream ALK targets include FOXO3a, CDKN1B/p27kip, cyclin D2, NIPA, RAC1, CDC42, p130CAS, SHP1, and PIKFYVE. ...
Furthermore, Runx2 controls the gene expression of cyclin D2, D3, and the CDK inhibitor p21(cip1) in hematopoietic cells. It ... has been shown that on a molecular level, Runx associates with the cdc2 partner cyclin B1 during mitosis. The phosphorylation ...
Cyclin D2 and Twist in in situ and invasive lobular breast carcinoma". International Journal of Cancer. 107 (6): 970-5. doi: ...
... including some induction of cyclin D2 and Cdk4. Additionally, sustained ERK activity seems to be important for phosphorylation ... Cyclin D-bound Cdks 4 and 6 are activated by Cdk-activating kinase and drive the cell towards the restriction point. Cyclin D, ... Sustained mitogen signaling promotes cell cycle entry largely through regulation of the G1 cyclins (cyclin D1-3) and their ... including the major G1 cyclin, cyclin D1. Myc also regulates expression of a wide variety of pro-proliferative and pro-growth ...
Some of the downstream gene targets of human Gli1 include regulators of the cell cycle and apoptosis such as cyclin D2 and ...
Another mammalian CDK, Cdk2, can form complexes with cyclins D1, D2, D3, E, or A. Cdk4 and Cdk6 interact with cyclins D1, D2, ... During G2 phase, cyclin A is degraded, while cyclin B is synthesized and cyclin B-Cdk1 complexes form. Not only are cyclin B- ... cyclin-dependent kinase (CDK), with a regulatory subunit, cyclin. Once cyclin-dependent kinases bind to cyclin, the formed ... Cyclin Cyclin-dependent kinase Malumbres M, Barbacid M. Mammalian cyclin-dependent kinases. Trends Biochem. Sci. 2005 Nov;30(11 ...
"Deregulation of cyclin D2 by juxtaposition with T-cell receptor alpha/delta locus in t(12;14)(p13;q11)-positive childhood T- ...
... in part through direct downregulation of cyclin D2 and cyclin E2. miR-26a also directly suppresses expression of estrogen ... miR-26a again suppresses tumorigenesis in nasopharyngeal cells in vivo, with suppressed expression of c-myc, cyclins D3 and E2 ... 2011). "Tumor-specific expression of microRNA-26a suppresses human hepatocellular carcinoma growth via cyclin-dependent and - ... and cyclin-dependent kinases CDK4 and CDK6. p14ARF and p21CIPI CDK inhibitor expression are conversely enhanced, mediated ...
... perhaps because the overexpression of cyclin D2 is weaker than Bcl2 overexpression in driving cells to accumulate and become ... both located at 9p21.3 and respectively encoding cyclin dependent kinase inhibitor 2A and cyclin dependent kinase inhibitor 2B ... The overexpression of cyclin D1 is thought to be a major factor in the development of ISMCL and its progression to MCL. ... The cyclin D1-expressing lymphocytes generally populate the inner layers of the marginal zone but on occasion some of these ...
The cyclin-D1-negative MCL subtypes usually result in lymphomagenesis via over-expression of cyclin D2, cyclin D3 or cyclin E, ... CD23 and CD200 are usually negative and cyclin-D1 (a cell cycle regulatory protein controlling transition from the G1 phase to ... MCL cells generally over-express cyclin D1 due to the t(11:14) translocation, a chromosomal translocation in the DNA. People ... A defining characteristic of MCL is mutation and overexpression of cyclin D1, a cell cycle gene, that contributes to the ...
... a protein Levuglandin D2 Prostaglandin D2 receptor, a G-protein coupled receptor Resolvin D2 Cyclin D2 (CCND2) Vitamin D2, or ... Look up D2 in Wiktionary, the free dictionary. D2, D02, D.II, D II or D-2 may refer to: Dublin 2, a Dublin, Ireland postcode D2 ... Marcelo D2 (born 1967), Brazilian rapper D2, an abbreviation for DOCSIS 2.0, an international telecommunications standard D2 ... électronique d2, now trading as LaCie D2 kit, a microprocessor development kit MEK6800D2 D-2 (video), a professional digital ...
This has been attributed to high mRNA levels of G1-related Cyclin D2 and Cdk4 genes and low levels of cell cycle regulatory ... The cell cycle is regulated by complex network of cyclins, cyclin-dependent kinases (Cdk), cyclin-dependent kinase inhibitors ( ... hESCs show that the activities of Cyclin E/Cdk2 and Cyclin A/Cdk2 complexes are cell cycle-dependent and the Rb checkpoint in ... However, in mESCs, this typically ordered and oscillatory activity of Cyclin-Cdk complexes is absent. Rather, the Cyclin E/Cdk2 ...
Protomers consist of Isoreceptors D1-D2 D1-D3 D2-D3 D2-D4 D2-D5 Non-isoreceptors D1-adenosine A1 D2-adenosine A2A D2-ghrelin ... Sustained D1 receptor activity is kept in check by Cyclin-dependent kinase 5. Dopamine receptor activation of Ca2+/calmodulin- ... D2 is encoded by the Dopamine receptor D2 gene (DRD2), of which there are two forms: D2Sh (short) and D2Lh (long): The D2Sh ... The D2 class of receptors produce the opposite effect, as they are Gαi and/or Gαo coupled receptors, which blocks the activity ...
... cyclin - cyclin A - cyclin B - cyclin E - cyclin-dependent kinase - cycloleucine - cyclosporin - cyclosporine - cystatin - ... dopamine D2 receptor - dopamine receptor - double helix - Drosophila - drugs - dynorphin eIF-2 - eIF-2 kinase - electrochemical ...
2004). "A novel partner for D-type cyclins: protein kinase A-anchoring protein AKAP95". Biochem. J. 378 (Pt 2): 673-9. doi: ... D2/Eg7 for chromosome condensation in mitotic extract". J. Cell Biol. 149 (3): 531-6. doi:10.1083/jcb.149.3.531. PMC 2174845. ... AKAP8 has been demonstrated to interact with: Cyclin D3 DDX5, MCM2, MYCBP, and PRKAR2A. GRCh38: Ensembl release 89: ... "A novel partner for D-type cyclins: protein kinase A-anchoring protein AKAP95". Biochem. J. 378 (Pt 2): 673-9. doi:10.1042/ ...
Rossitto M, Ujjan S, Poulat F, Boizet-Bonhoure B (2015). "Multiple roles of the prostaglandin D2 signaling pathway in ... Cyclin D1, Cdk4, and Insulin-like growth factor 1; and e) regulating agents such as HSP70, GPR78, Gadd153, Ubiquitin B, and ... "Prostaglandin D2 inhibits hair growth and is elevated in bald scalp of men with androgenetic alopecia". Science Translational ... a glutathione-independent synthase termed lipocalin-type Prostaglandin D2 synthase (PTGDS or L-PGDS) and a glutathione- ...
During prometaphase, dynactin also helps target polo-like kinase 1 (Plk1) to kinetochores through cyclin dependent kinase 1 ( ... but can be induced to form a tight complex in the presence of the N-terminal 400 amino acids of Bicaudal D2 (BICD2), a cargo ...
CDK2/cyclin E and CDK2/cyclin A complexes. Studies using TG mice model suggested the existence of an autocrine loop involving ... Recent studies described an inhibitor (D2) that block PELP1 interactions with AR. Since PELP1 interacts with histone ... Nair BC, Nair SS, Chakravarty D, Challa R, Manavathi B, Yew PR, Kumar R, Tekmal RR, Vadlamudi RK (September 2010). "Cyclin- ... the CDK-cyclin D1-PELP1 axis in promoting mammary tumorigenesis PELP1 has a histone binding domain; functions as a reader of ...
Phospholipase D2 (PLD-2) which is localized in the growth cone and is involved in actin cytoskeleton rearrangement, can be ... Studies suggest that glycogen synthase kinase-3β (GSK-3β) and cyclin-dependent protein kinase 5 (Cdk5) are highly expressed in ...
... cyclin a MeSH D23.348.353.120 - cyclin b MeSH D23.348.353.161 - cyclin d1 MeSH D23.348.353.180 - cyclin e MeSH D23.348.383.110 ... prostaglandin d2 MeSH D23.469.050.175.725.780 - prostaglandins e MeSH D23.469.050.175.725.780.050 - alprostadil MeSH D23.469. ...
Brooks AR, Shiffman D, Chan CS, Brooks EE, Milner PG (Apr 1996). "Functional analysis of the human cyclin D2 and cyclin D3 ... Cyclins function as regulators of cyclin-dependent kinases. Different cyclins exhibit distinct expression and degradation ... G1/S-specific cyclin-D2 is a protein that in humans is encoded by the CCND2 gene. The protein encoded by this gene belongs to ... "Entrez Gene: CCND2 cyclin D2". Mirzaa GM, Parry DA, Fry AE, Giamanco KA, Schwartzentruber J, Vanstone M, Logan CV, Roberts N, ...
David Bartels lab contains the insert Cyclin D2 and is published in Cell. 2009 Aug 21. 138(4):673-84. This plasmid is ... Plasmid pMSCV Cyclin D2 long-wt from Dr. ... pMSCV Cyclin D2 long-wt was a gift from David Bartel (Addgene ...
You need info about Human Cyclin-D2 (CCND2) ELISA Kit or any other Gentaur produtct? Contact us on Live Chat Our specialist are ...
CCND2: cyclin D2. *CD40LG: CD40 ligand. *CDAN1: codanin 1. *CDC6: cell division cycle 6 ...
Cyclin D2 * Eukaryotic Initiation Factor-3 * GREM1 protein, human * Intercellular Signaling Peptides and Proteins ...
Transcriptional regulation of cyclin D2 by the PKA pathway and inducible cAMP early repressor in granulosa cells. In: Biology ... Transcriptional regulation of cyclin D2 by the PKA pathway and inducible cAMP early repressor in granulosa cells. Biology of ... Muñiz, L. C., Yehia, G., Mémin, E., Ratnakar, P. V. A. L., & Molina, C. A. (2006). Transcriptional regulation of cyclin D2 by ... Transcriptional regulation of cyclin D2 by the PKA pathway and inducible cAMP early repressor in granulosa cells. / Muñiz, Luis ...
Expression of cyclin D1, cyclin D2, and N-myc in embryos of the direct developing frog Eleutherodactylus coqui, with a focus on ... Nath, K., Fisher, C., & Elinson, R. (2013). Expression of cyclin D1, cyclin D2, and N-myc in embryos of the direct developing ...
Heart attack recovery aided by injecting heart muscle cells that overexpress cyclin D2 ...
Cyclin D2 overexpression drives B1a-derived MCL-like lymphoma in mice Tim Pieters (UGent) , Sara TSas (UGent) , Stijn Vanhee ( ...
Redox regulation of cardiomyocyte cell cycling via an ERK1/2 and c-Myc-dependent activation of cyclin D2 transcription. Murray ...
Zymosan A also raises cyclin D2 levels suggesting a role for the latter in macrophage activation besides proliferation. It ...
De novo CCND2 mutations leading to stabilization of cyclin D2 cause megalencephaly-polymicrogyria-polydactyly-hydrocephalus ...
The Dmp1 (cyclin D binding myb-like protein 1; Dmtf1) gene was isolated through its virtue for binding to cyclin D2. It is a ...
2016). High Glucose Concentration Induces Endothelial Cell Proliferation by Regulating Cyclin-D2-Related miR-98. J. Cell. Mol. ... 2011). Peptide-mediated Disruption of Calmodulin-Cyclin E Interactions Inhibits Proliferation of Vascular Smooth Muscle Cells ... such as cyclin, which is closely associated with the proliferation of endothelial cells (Li et al., 2016; Hui et al., 2011). ...
In occasional cells, this crossing over may lead to increased 12p copy number and overexpression of cyclin D2. The cell ...
Cyclin D2 overexpression drives B1a-derived MCL-like lymphoma in mice.. Citation ...
ATCYCD2;1, Cyclin D2;1, F14M13.11, F14M13_11, AT2G22490. cyclin-D2-1 ... cyclin-dependent protein serine/threonine kinase regulator activity [ISS]*protein binding [IPI] ...
... anti-cyclin D1 (Novocastra); anti-cyclin D2 and anti-cyclin D3 (Santa Cruz Biotechnology, Santa Cruz, CA); anti-retinoblastoma ... In combination, however, a further decrease in cyclin D1 and D2 protein was observed (Fig. 4B, middle). Cyclin D complexed with ... showed that both RAD001 and letrozole similarly reduced cyclin D1 and D2 protein expression, with cyclin D3 levels unaffected. ... Both agents caused minor decreases in cyclin D1 and D2 expression after 4 hours of treatment, suggesting that these events are ...
2003). Methylation of Cyclin D2 Is Observed Frequently in Pancreatic Cancer But Is Also an Age-Related Phenomenon in ... Various methylation markers have been reported in pancreatic ductal adenocarcinoma, such as p16, hMLH1 and hMLH2, and cyclin D2 ... The better-known tumor suppressor gene includes gene cyclin-dependent kinase inhibitor 2A (CDKN2A) (Zhao et al., 2016), breast ...
Glucose regulates cyclin D2 expression in quiescent and replicating pancreatic β-cells through glycolysis and calcium channels ... and p21 cyclin kinase inhibitors in old mice have not changed on exposure to young circulation that led to increased ... multiple other cyclin kinase inhibitors are upregulated with old age (7), but the functional significance of these genes is ...
In occasional cells, this crossing over may lead to increased 12p copy number and overexpression of cyclin D2. The cell ...
... downstream targets of STAT3 signaling are well known to be mediators of cancer initiation and progression such as Cyclin D1/D2 ...
Cole, Alicia M. (2010) Investigating the functional significance of the upregulation of Cyclin D2 and p21 following Apc loss in ... Walker, Roderick G. (2008) Leishmania CRK3:CYC6 cyclin-dependent kinase as a drug target. PhD thesis, University of Glasgow. ... Chantkran, Wittawat (2020) An investigation of a novel cyclin-dependent kinase inhibitor as a treatment option for Acute ... Gomes, Felipe Campelo (2007) Analysis of cyclin dependent kinases in Leishmania. PhD thesis, University of Glasgow. ...
As normal cells entered density-dependent arrest, cyclin D1 decreased while cyclin D2 was induced and replaced D1 in Cdk4 ... as it occurred in the absence of p27Kip1 induction and cyclin D1 levels remained high. This demonstrates that although ...
... cyclin D2, Ras association (RalGDS/AF-6) domain family member 1, serine peptidase inhibitor Kunitz type 2, cystic fibrosis ... However, RALB silencing caused a modest inhibition of cell cycle progression, which in H1299 cells was associated with Cyclin ... and cyclin-dependent kinase inhibitor 2A (p16INK4a) in 101 primary CRCs (67 stage III and 34 stage IV) and related lymph node ... cyclin-dependent kinase inhibitor 2A (CDKN2A), retinoic acid receptor beta (RARB2), estrogen receptor 1 (ESR1), progesterone ...
... with induction of islet cyclin D2 expression. Am J Physiol Endocrinol Metab. 2013 Jul 01; 305(1):E149-59. ...
Additional statements about protein catabolism of cyclin D2 Additional statements about dna methylation of cyclin D2 ... Additional statements about acetylation of cyclin D2 ... Show family profile for cyclin D2 + cyclin D2 regulates 52 ... Additional statements about methylation of cyclin D2 ... of cyclin D2 Additional statements about localization of cyclin ... Additional statements about glycosylation of cyclin D2 ... Additional statements about undefined regulation of cyclin D2 ...
In this study, we evaluated cyclin D1, D2 and D3 protein expression in AL amyloidosis, and compared cyclin D positivity to ... Cyclin D dysregulation has been proposed to be a common mechanism in PC disorders, as in multiple myeloma; the majority of ... patients have dysregulated cyclin D expression.6 This has not been extensively investigated in AL amyloidosis. ...
The main cyclin-cdks complexes formed in vertebrate cells are cyclin D-cdk4 (G0/G1), cyclin E-cdk2 (G1/S), cyclin A-cdk2 (S) ... The main cyclin-cdks complexes formed in vertebrate cells are cyclin D-cdk4 (G0/G1), cyclin E-cdk2 (G1/S), cyclin A-cdk2 (S) ... Cyclin A may also form a complex with the adenovirus oncoprotein E1A which has DNA binding activity. Human cyclin A has been ... Cyclin A may also form a complex with the adenovirus oncoprotein E1A which has DNA binding activity. Human cyclin A has been ...
  • In human monocytic cell lines U-937 and THP-1, LeTx induced cell cycle arrest in Go-Gi phase by rapid down-regulation of cyclin D1/D2 and checkpoint kinase 1 through MEK1 inhibition. (uwo.ca)
  • ATCC CCL-243) were probed with the mouse anti-human cyclin A antibody at concentration of 2.0 µg/mL (lane 1), 1.0 µg/mL (lane 2), and 0.5 µg/mL (lane 3). (bdbiosciences.com)
  • G1/S-specific cyclin-D2 is a protein that in humans is encoded by the CCND2 gene. (wikipedia.org)
  • The protein encoded by this gene belongs to the highly conserved cyclin family, whose members are characterized by a dramatic periodicity in protein abundance through the cell cycle. (wikipedia.org)
  • In silico analysis of the mouse, rat, and human cyclin D2 promoters identified two CRE-binding protein sites, a conserved proximal element and a less conserved distal element relative to the translation start site. (montclair.edu)
  • In this study, we evaluated cyclin D1, D2 and D3 protein expression in AL amyloidosis, and compared cyclin D positivity to other conventional laboratory parameters as a diagnostic tool and as a potential biomarker for minimal residual disease. (bmj.com)
  • Specific substrates for cdk-cyclin complexes include nuclear lamins, histones, oncogenes (e.g., c-abl and SV40 large T-Ag), tumor suppressor genes (e.g., retinoblastoma protein, Rb), nucleolin and others. (bdbiosciences.com)
  • Faha B, Ewen ME, Tsai LH, Livingston DM, Harlow E. Interaction between human cyclin A and adenovirus E1A-associated p107 protein. (bdbiosciences.com)
  • In each of the two cases, the amplified cyclin gene was overexpressed at the protein or mRNA level. (elsevierpure.com)
  • Regulatory component of the cyclin D2-CDK4 (DC) complex that phosphorylates and inhibits members of the retinoblastoma (RB) protein family including RB1 and regulates the cell-cycle during G(1)/S transition. (cusabio.cn)
  • Our results provide novel insights into the function of EBNA3C on cell progression by regulating the cyclin D2 protein and raise the possibility of the development of new anticancer therapies against EBV-associated cancers. (cusabio.cn)
  • Cyclins function as regulators of cyclin-dependent kinases. (wikipedia.org)
  • Cyclins and cyclin-dependent kinases (cdks) are evolutionarily conserved proteins that are essential for cell-cycle control in eukaryotes. (bdbiosciences.com)
  • In pro-B cells PTBP1 ensures precise synchronisation of the activity of cyclin dependent kinases at distinct stages of the cell cycle, suppresses S-phase entry and promotes progression into mitosis. (ox.ac.uk)
  • These data suggest that a variety of cyclin genes can play a role in human tumorigenesis and that cyclins D2 and E are particularly important in a subset of colorectal neoplasms. (elsevierpure.com)
  • The main cyclin-cdks complexes formed in vertebrate cells are cyclin D-cdk4 (G0/G1), cyclin E-cdk2 (G1/S), cyclin A-cdk2 (S) and cyclin B1-cdk1 (G2/M). These complexes are regulated by activating and inhibitory phosphorylation events, as well as by interactions with small regulatory proteins including p21 and p27Kip1. (bdbiosciences.com)
  • As normal cells entered density-dependent arrest, cyclin D1 decreased while cyclin D2 was induced and replaced D1 in Cdk4 complexes. (ku.dk)
  • Cyclins (regulatory subunits) bind to cdks (catalytic subunits) to form complexes that regulate the progression of the cell cycle. (bdbiosciences.com)
  • Cyclin D-CDK4 complexes are major integrators of various mitogenenic and antimitogenic signals. (cusabio.cn)
  • You need info about Human Cyclin-D2 (CCND2) ELISA Kit or any other Gentaur produtct? (gentaurshop.com)
  • In occasional cells, this crossing over may lead to increased 12p copy number and overexpression of cyclin D2. (medscape.com)
  • Yet, the responsive elements and transcription factors accounting for the gene expression of cyclin D2 in the ovary have not been fully characterized. (montclair.edu)
  • Using primary cultures of rat granulosa cells and immortalized mouse granulosa cells, we demonstrate a mechanism for the regulation of cyclin D2 at the level of transcription via a PKA-dependent signaling mechanism. (montclair.edu)
  • These results showed a CRE within the upstream region of Ccnd2 that is (at least partly) implicated in the stimulation and repression of cyclin D2 transcription. (montclair.edu)
  • The genetic status of cyclin genes was examined in a panel of 47 colorectal carcinoma cell lines. (elsevierpure.com)
  • CpG methylation of the FHIT, FANCF, cyclin-D2, BRCA2 and RUNX3 genes in Granulosa cell tumors (GCTs) of ovarian origin. (cancercentrum.se)
  • PTBP1 controls mRNA abundance and alternative splicing of important cell cycle regulators including CYCLIN-D2, c-MYC, p107 and CDC25B. (ox.ac.uk)
  • Different cyclins exhibit distinct expression and degradation patterns which contribute to the temporal coordination of each mitotic event. (wikipedia.org)
  • Expression of cyclin D1, cyclin D2, and N-myc in embryos of the direct" by Kimberly Nath, Cara Fisher et al. (duq.edu)
  • cell proliferation increases early in high-fat feeding in mice, concurrent with metabolic changes, with induction of islet cyclin D2 expression. (umassmed.edu)
  • the majority of patients have dysregulated cyclin D expression. (bmj.com)
  • Cyclin D2 gene variance and expression level in pediatric acute lymphoblastic leukemia. (cdc.gov)
  • This cyclin forms a complex with and functions as a regulatory subunit of CDK4 or CDK6, whose activity is required for cell cycle G1/S transition. (wikipedia.org)
  • Activated Akt inhibited GSK3 and prevented proteasome-mediated cyclin D1 degradation in LeTx-intoxicated THP-1 cells. (uwo.ca)
  • Cyclin D2 (Ccnd2) is an essential gene for folliculogenesis, as null mutation in mice impairs granulosa cell proliferation in response to FSH. (montclair.edu)
  • Human cyclin A has been reported to migrate between 54-60 kDa by SDS-PAGE and clone BF683 reportedly does not cross-react with mouse, rat or mink cyclin A. (bdbiosciences.com)
  • The CD274/JNK/Cyclin D2 pathway promotes the cell cycle entry of LIC. (cusabio.cn)
  • Surprisingly, this delayed arrest was molecularly distinct from contact inhibition of normal cells, as it occurred in the absence of p27 Kip1 induction and cyclin D1 levels remained high. (ku.dk)
  • The promoter activity of cyclin D2 was shown to be induced by FSH and the catalytic alpha subunit of PKA (PRKACA), and this activity was repressible by inducible cAMP early repressor (ICER), a cAMP response element (CRE) modulator isoform. (montclair.edu)
  • Cyclin A may also form a complex with the adenovirus oncoprotein E1A which has DNA binding activity. (bdbiosciences.com)
  • Zymosan A also raises cyclin D2 levels suggesting a role for the latter in macrophage activation besides proliferation. (wikipedia.org)
  • Cyclin A is involved in both S-phase and G2/M transitions of the cell cycle through its association with cdk2 and cdk1, respectively. (bdbiosciences.com)
  • Cyclin Dl, previously shown to be amplified in breast and other tumors, was not amplified in these cancers. (elsevierpure.com)
  • G1/S-specific cyclin-D2 is a protein that in humans is encoded by the CCND2 gene. (wikipedia.org)
  • Cyclin D2 (CCND2) is a crucial player in cell cycle regulation. (nih.gov)
  • You need info about Human Cyclin-D2 (CCND2) ELISA Kit or any other Gentaur produtct? (gentaurshop.com)
  • The CCND2 gene provides instructions for making a protein called cyclin D2. (medlineplus.gov)
  • The cyclin-dependent kinase inhibitor p21 is induced by both p53-dependent and -independent mechanisms following stress, and induction of p21 may cause cell cycle arrest. (aacrjournals.org)
  • Cyclin D2's role in the cell division cycle makes it a key controller of the rate of cell growth and division (proliferation) in the body. (medlineplus.gov)
  • The resulting buildup of cyclin D2 in cells triggers them to continue dividing when they otherwise would not have, leading to abnormal cell proliferation. (medlineplus.gov)
  • It is less clear how a buildup of cyclin D2 contributes to polydactyly, although the extra digits are probably related to abnormal cell proliferation in the developing hands and feet. (medlineplus.gov)
  • Zymosan A also raises cyclin D2 levels suggesting a role for the latter in macrophage activation besides proliferation. (wikipedia.org)
  • 18. Cyclin D2 is overexpressed in proliferation centers of chronic lymphocytic leukemia/small lymphocytic lymphoma. (nih.gov)
  • Cyclin D proteins promote proliferation in G1 and typically are down-regulated before differentiation. (ca.gov)
  • Active cyclin/Cdk complexes phosphorylate and inactivate members of the retinoblastoma protein (Rb) family that are negative regulators of G 1 and S-phase progression, leading to induction of E2F-regulated gene expression and cell proliferation. (aacrjournals.org)
  • In glioma ( 28 ) and in vascular smooth muscle cells ( 29 ), p21 facilitates active cyclin-Cdk complex formation and induces cell proliferation. (aacrjournals.org)
  • Experiments using KNOCKOUT MICE suggest a role for cyclin D2 in granulosa cell proliferation and gonadal development. (bvsalud.org)
  • 2018. Epstein-Barr Virus nuclear antigen 3C facilitates cell proliferation by regulating Cyclin D2. (sustech.edu.cn)
  • Traditional western blots showed reduced expression degrees of cyclin D1, CDK4, and CDK6 in cells overexpressing LINC01089, which verified our observations in the cell proliferation assays. (forumbcn2004.org)
  • As a result, the underlying system where LINC01089 S 32212 HCl inhibits BC cell proliferation probably involves suppressing the experience of D-type cyclin-CDK4/6 complexes and eventually inducing G0/G1 stage arrest. (forumbcn2004.org)
  • This cyclin forms a complex with and functions as a regulatory subunit of CDK4 or CDK6, whose activity is required for cell cycle G1/S transition. (wikipedia.org)
  • Although one molecule of p21 is sufficient to inhibit cyclin/Cdk complexes ( 22 ), Cip/Kip CKIs have been detected in active cyclin D/Cdk4 complexes ( 24 - 27 ). (aacrjournals.org)
  • p21 was shown to stabilize interactions between Cdk4 and cyclin D and promote the formation of active complexes in a concentration-dependent manner ( 27 ). (aacrjournals.org)
  • Regulatory component of the cyclin D2-CDK4 (DC) complex that phosphorylates and inhibits members of the retinoblastoma (RB) protein family including RB1 and regulates the cell-cycle during G(1)/S transition (PubMed:8114739, PubMed:18827403). (wuxibiortus.com)
  • Cyclin D-CDK4 complexes are major integrators of various mitogenenic and antimitogenic signals (PubMed:8114739, PubMed:18827403). (wuxibiortus.com)
  • Component of the ternary complex, cyclin D2/CDK4/CDKN1B, required for nuclear translocation and activity of the cyclin D-CDK4 complex (By similarity). (nih.gov)
  • p21CIP1 is a potent, tight-binding inhibitor of Cdks and can inhibit the phosphorylation of Rb by cyclin A-Cdk2, cyclin E-Cdk2, cyclin D1-Cdk4, and cyclin D2-Cdk4 complexes. (nih.gov)
  • The protein encoded by this gene belongs to the highly conserved cyclin family, whose members are characterized by a dramatic periodicity in protein abundance through the cell cycle. (wikipedia.org)
  • Inactivation of cyclin D2 gene in prostate cancers by aberrant promoter methylation. (nih.gov)
  • We investigated the epigenetic silencing of Cyclin D2 gene in prostate cancers and correlated the data with clinicopathological features. (nih.gov)
  • Moreover, UBE2O downregulated the transcriptional activity of c-Maf and the expression of cyclin D2, a typical gene modulated by c-Maf. (biomedcentral.com)
  • Gene promoter hypermethylation of RAR- , HIN-1 , Cyclin D2 and Twist has been reported to be a frequent and tumour specific event in in situ and invasive breast cancer of both ductal and lobular types [10]. (bio2009.org)
  • The D cyclins were expressed differentially in chronic lymphocytic leukemia (CLL), prolymphocytic leukemia (PLL), and mantle cell lymphoma (MCL) with strong staining of cyclin D1 and D2 in MCL, strong staining of cyclin D1 but weak staining of cyclin D2 in 4 of 5 PLLs, and low-level staining for both cyclins in most CLLs. (medscape.com)
  • 15. Novel expression of cyclin-dependent kinase inhibitors in human B-cell precursors. (nih.gov)
  • Cyclins are a family of proteins that control how cells proceed through the multi-step cycle of cell division. (medlineplus.gov)
  • Tsunekawa Y, Kikkawa T, Osumi N. Asymmetric inheritance of Cyclin D2 maintains proliferative neural stem/progenitor cells: a critical event in brain development and evolution. (medlineplus.gov)
  • 2. The expression of SOX11, cyclin D1, cyclin D2, and cyclin D3 in B-cell lymphocytic proliferative diseases. (nih.gov)
  • 19. Distinct proliferative and transcriptional effects of the D-type cyclins in vivo. (nih.gov)
  • Interacts with D-type G1 cyclins during interphase at G1 to form a pRB/RB1 kinase and controls the entrance into the cell cycle. (wuxibiortus.com)
  • Cyclin D2 helps to regulate a step in the cycle called the G1-S transition, in which the cell moves from the G1 phase, when cell growth occurs, to the S phase, when the cell's DNA is copied (replicated) in preparation for cell division. (medlineplus.gov)
  • We analyzed protein expression of cyclin D1, cyclin D2, and cyclin D3 using high-resolution enzymatic amplification staining and flow cytometry in the neoplastic cells from 80 patients with CD5+ B-cell lymphoproliferative disorders. (medscape.com)
  • All 3 D cyclins are key cell cycle regulatory molecules involved in oncogenesis. (medscape.com)
  • [ 29 , 30 , 31 ] Previous analyses of cyclin D1 expression in low-grade B-cell lymphoproliferative disorders by flow cytometry have used an antibody that cross-reacts with cyclin D2. (medscape.com)
  • Therefore, we evaluated the expression of cyclin D1, cyclin D2, and cyclin D3 using EAS and flow cytometry in 80 CD5+ B-cell lymphoproliferative disorders. (medscape.com)
  • Cite this: D Cyclins in CD5+ B-Cell Lymphoproliferative Disorders - Medscape - Feb 01, 2006. (medscape.com)
  • 4. Relationship between cyclin D1 and p21(Waf1/Cip1) during differentiation of human myeloid leukemia cell lines. (nih.gov)
  • Cyclin D1 promotes neurogenesis in the developing spinal cord in a cell cycle-independent manner. (ca.gov)
  • Interestingly, we found that Cyclin D1, a well-known key positive regulator of the cell cycle, unexpectedly regulates neuronal specification. (ca.gov)
  • Such role of Cyclin D1 in neuronal specification is not shared by other Cyclin Ds and is independent on its action on the cell cycle. (ca.gov)
  • These data identify a cell cycle-independent function for Cyclin D1 in promoting neuronal differentiation, along with a potential genetic pathway through which this function is exerted. (ca.gov)
  • It represents approximately 30% of diffuse large B-cell lymphomas, and is characterized by the expression of CD44, PKCbeta1, Cyclin D2, BCL-2, and IRF4/MUM1 genes. (mycancergenome.org)
  • Key targets of aberrant promoter hypermethylation in breast cancer development include genes involved in all stages of tumorigenesis such as DNA repair ( BRCA1 ), receptors ( ER , RAR- ), intracellular signalling pathways, cell cycle regulation ( Cyclin D2 , p16 INK4A ), transcription factors 188011-69-0 manufacture ( Twist ), adhesion molecules ( E-cadherin ) and apoptosis ( HOXA5 ) [7-14]. (bio2009.org)
  • Most importantly, this function is potent enough to convert Cyclin D2-expressing glial-restricted precursors into neurons. (ca.gov)
  • The cyclin-dependent kinase Cdk2 associates with cyclins A, D, and E and has been implicated in the control of the G1 to S phase transition in mammals. (nih.gov)
  • CIP1 encodes a novel 21 kd protein that is found in cyclin A, cyclin D1, cyclin E, and Cdk2 immunoprecipitates. (nih.gov)
  • Here we show that motoneuron progenitors in the embryonic spinal cord persistently express Cyclin D1 during the initial phase of differentiation, while down-regulating Cyclin D2. (ca.gov)
  • Cyclin D2 promoter methylation was analyzed in 101 prostate cancer samples by methylation-specific PCR. (nih.gov)
  • However, cyclin D1 levels were significantly higher in ZAP-70+ CLL cases, although no association between ZAP-70 and cyclin D2 was detected. (medscape.com)
  • The methylation status of Cyclin D2 was correlated with the methylation of nine other tumor suppressor genes published previously from our laboratory on the same set of samples (R. Maruyama et al. (nih.gov)
  • We also compared methylation of cyclin D2 with methylation of nine tumor suppressor genes [published previously from our laboratory (R. Maruyama et al. (nih.gov)
  • Los experimentos con empleo de RATONES NOQUEADOS (con genes desactivados) sugieren un papel de la ciclina D2 en la proliferación de las células de la granulosa y en el desarrollo gonadal. (bvsalud.org)
  • The neurogenic function of Cyclin D1 appears to be mediated, directly or indirectly, by Hes6, a proneurogenic basic helic-loop-helix transcription factor. (ca.gov)
  • A cyclin D subtype which is regulated by GATA4 TRANSCRIPTION FACTOR. (bvsalud.org)