HeLa Cells: 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.Molecular Sequence Data: 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.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Cell Nucleus: 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)Transfection: 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.Poliovirus: A species of ENTEROVIRUS which is the causal agent of POLIOMYELITIS in humans. Three serotypes (strains) exist. Transmission is by the fecal-oral route, pharyngeal secretions, or mechanical vector (flies). Vaccines with both inactivated and live attenuated virus have proven effective in immunizing against the infection.Transcription, Genetic: The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.Cell Line: Established cell cultures that have the potential to propagate indefinitely.Amino Acid Sequence: 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.DNA-Binding Proteins: 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.RNA, Messenger: 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.Promoter Regions, Genetic: 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.Nuclear Proteins: 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.Adenoviruses, Human: Species of the genus MASTADENOVIRUS, causing a wide range of diseases in humans. Infections are mostly asymptomatic, but can be associated with diseases of the respiratory, ocular, and gastrointestinal systems. Serotypes (named with Arabic numbers) have been grouped into species designated Human adenovirus A-F.Mitosis: 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.DNA: 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).Kinetics: The rate dynamics in chemical or physical systems.Protein Binding: 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.Plasmids: Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.Transcription Factors: Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.Cloning, Molecular: The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.Molecular Weight: The sum of the weight of all the atoms in a molecule.Ribonucleoproteins: Complexes of RNA-binding proteins with ribonucleic acids (RNA).Recombinant Fusion Proteins: 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.Apoptosis: 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.Protein Biosynthesis: The biosynthesis of PEPTIDES and PROTEINS on RIBOSOMES, directed by MESSENGER RNA, via TRANSFER RNA that is charged with standard proteinogenic AMINO ACIDS.Cell Cycle: 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.Cell Extracts: Preparations of cell constituents or subcellular materials, isolates, or substances.Cytoplasm: 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)Gene Expression Regulation: 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.Viral Proteins: Proteins found in any species of virus.Mutation: 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.DNA Replication: The process by which a DNA molecule is duplicated.Phosphorylation: The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.Electrophoresis, Polyacrylamide Gel: Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.RNA, Small Interfering: 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.Recombinant Proteins: Proteins prepared by recombinant DNA technology.UridineMicroscopy, Fluorescence: Microscopy of specimens stained with fluorescent dye (usually fluorescein isothiocyanate) or of naturally fluorescent materials, which emit light when exposed to ultraviolet or blue light. Immunofluorescence microscopy utilizes antibodies that are labeled with fluorescent dye.RNA: A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. (Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)Cell Survival: The span of viability of a cell characterized by the capacity to perform certain functions such as metabolism, growth, reproduction, some form of responsiveness, and adaptability.Cell Membrane: The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.Cell Nucleolus: Within most types of eukaryotic CELL NUCLEUS, a distinct region, not delimited by a membrane, in which some species of rRNA (RNA, RIBOSOMAL) are synthesized and assembled into ribonucleoprotein subunits of ribosomes. In the nucleolus rRNA is transcribed from a nucleolar organizer, i.e., a group of tandemly repeated chromosomal genes which encode rRNA and which are transcribed by RNA polymerase I. (Singleton & Sainsbury, Dictionary of Microbiology & Molecular Biology, 2d ed)RNA Interference: 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.Bacterial Adhesion: Physicochemical property of fimbriated (FIMBRIAE, BACTERIAL) and non-fimbriated bacteria of attaching to cells, tissue, and nonbiological surfaces. It is a factor in bacterial colonization and pathogenicity.Fluorescent Antibody Technique: Test for tissue antigen using either a direct method, by conjugation of antibody with fluorescent dye (FLUORESCENT ANTIBODY TECHNIQUE, DIRECT) or an indirect method, by formation of antigen-antibody complex which is then labeled with fluorescein-conjugated anti-immunoglobulin antibody (FLUORESCENT ANTIBODY TECHNIQUE, INDIRECT). The tissue is then examined by fluorescence microscopy.Rhinovirus: A genus of PICORNAVIRIDAE inhabiting primarily the respiratory tract of mammalian hosts. It includes over 100 human serotypes associated with the COMMON COLD.Carrier Proteins: Transport proteins that carry specific substances in the blood or across cell membranes.RNA Splicing: The ultimate exclusion of nonsense sequences or intervening sequences (introns) before the final RNA transcript is sent to the cytoplasm.Virus Replication: The process of intracellular viral multiplication, consisting of the synthesis of PROTEINS; NUCLEIC ACIDS; and sometimes LIPIDS, and their assembly into a new infectious particle.RNA, Heterogeneous Nuclear: Nuclear nonribosomal RNA larger than about 1000 nucleotides, the mass of which is rapidly synthesized and degraded within the cell nucleus. Some heterogeneous nuclear RNA may be a precursor to mRNA. However, the great bulk of total hnRNA hybridizes with nuclear DNA rather than with mRNA.Interphase: The interval between two successive CELL DIVISIONS during which the CHROMOSOMES are not individually distinguishable. It is composed of the G phases (G1 PHASE; G0 PHASE; G2 PHASE) and S PHASE (when DNA replication occurs).RNA, Viral: Ribonucleic acid that makes up the genetic material of viruses.Green Fluorescent Proteins: Protein analogs and derivatives of the Aequorea victoria green fluorescent protein that emit light (FLUORESCENCE) when excited with ULTRAVIOLET RAYS. They are used in REPORTER GENES in doing GENETIC TECHNIQUES. Numerous mutants have been made to emit other colors or be sensitive to pH.Adenovirus Early Proteins: Proteins encoded by adenoviruses that are synthesized prior to, and in the absence of, viral DNA replication. The proteins are involved in both positive and negative regulation of expression in viral and cellular genes, and also affect the stability of viral mRNA. Some are also involved in oncogenic transformation.Centrifugation, Density Gradient: Separation of particles according to density by employing a gradient of varying densities. At equilibrium each particle settles in the gradient at a point equal to its density. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)RNA Precursors: RNA transcripts of the DNA that are in some unfinished stage of post-transcriptional processing (RNA PROCESSING, POST-TRANSCRIPTIONAL) required for function. RNA precursors may undergo several steps of RNA SPLICING during which the phosphodiester bonds at exon-intron boundaries are cleaved and the introns are excised. Consequently a new bond is formed between the ends of the exons. Resulting mature RNAs can then be used; for example, mature mRNA (RNA, MESSENGER) is used as a template for protein production.Cell Division: The fission of a CELL. It includes CYTOKINESIS, when the CYTOPLASM of a cell is divided, and CELL NUCLEUS DIVISION.Vaccinia virus: The type species of ORTHOPOXVIRUS, related to COWPOX VIRUS, but whose true origin is unknown. It has been used as a live vaccine against SMALLPOX. It is also used as a vector for inserting foreign DNA into animals. Rabbitpox virus is a subspecies of VACCINIA VIRUS.Protein Transport: The process of moving proteins from one cellular compartment (including extracellular) to another by various sorting and transport mechanisms such as gated transport, protein translocation, and vesicular transport.Blotting, Western: 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.Dactinomycin: A compound composed of a two CYCLIC PEPTIDES attached to a phenoxazine that is derived from STREPTOMYCES parvullus. It binds to DNA and inhibits RNA synthesis (transcription), with chain elongation more sensitive than initiation, termination, or release. As a result of impaired mRNA production, protein synthesis also declines after dactinomycin therapy. (From AMA Drug Evaluations Annual, 1993, p2015)Luminescent Proteins: Proteins which are involved in the phenomenon of light emission in living systems. Included are the "enzymatic" and "non-enzymatic" types of system with or without the presence of oxygen or co-factors.Ribonucleoproteins, Small Nuclear: Highly conserved nuclear RNA-protein complexes that function in RNA processing in the nucleus, including pre-mRNA splicing and pre-mRNA 3'-end processing in the nucleoplasm, and pre-rRNA processing in the nucleolus (see RIBONUCLEOPROTEINS, SMALL NUCLEOLAR).Enterovirus B, Human: A species of ENTEROVIRUS infecting humans and containing 36 serotypes. It is comprised of all the echoviruses and a few coxsackieviruses, including all of those previously named coxsackievirus B.Heterogeneous-Nuclear Ribonucleoproteins: A family of ribonucleoproteins that were originally found as proteins bound to nascent RNA transcripts in the form of ribonucleoprotein particles. Although considered ribonucleoproteins they are primarily classified by their protein component. They are involved in a variety of processes such as packaging of RNA and RNA TRANSPORT within the nucleus. A subset of heterogeneous-nuclear ribonucleoproteins are involved in additional functions such as nucleocytoplasmic transport (ACTIVE TRANSPORT, CELL NUCLEUS) of RNA and mRNA stability in the CYTOPLASM.RNA-Binding Proteins: Proteins that bind to RNA molecules. Included here are RIBONUCLEOPROTEINS and other proteins whose function is to bind specifically to RNA.DNA, Complementary: Single-stranded complementary DNA synthesized from an RNA template by the action of RNA-dependent DNA polymerase. cDNA (i.e., complementary DNA, not circular DNA, not C-DNA) is used in a variety of molecular cloning experiments as well as serving as a specific hybridization probe.Cell-Free System: A fractionated cell extract that maintains a biological function. A subcellular fraction isolated by ultracentrifugation or other separation techniques must first be isolated so that a process can be studied free from all of the complex side reactions that occur in a cell. The cell-free system is therefore widely used in cell biology. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p166)Cytotoxins: Substances that are toxic to cells; they may be involved in immunity or may be contained in venoms. These are distinguished from CYTOSTATIC AGENTS in degree of effect. Some of them are used as CYTOTOXIC ANTIBIOTICS. The mechanism of action of many of these are as ALKYLATING AGENTS or MITOSIS MODULATORS.Hot Temperature: Presence of warmth or heat or a temperature notably higher than an accustomed norm.TritiumGenes: A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms.Cycloheximide: Antibiotic substance isolated from streptomycin-producing strains of Streptomyces griseus. It acts by inhibiting elongation during protein synthesis.RNA Cap-Binding Proteins: Proteins that specifically bind to RNA CAPS and form nuclear cap binding protein complexes. In addition to stabilizing the 5' end of mRNAs, they serve a diverse array of functions such as enhancing mRNA transport out of the CELL NUCLEUS and regulating MRNA TRANSLATION in the CYTOPLASM.Chloramphenicol O-Acetyltransferase: An enzyme that catalyzes the acetylation of chloramphenicol to yield chloramphenicol 3-acetate. Since chloramphenicol 3-acetate does not bind to bacterial ribosomes and is not an inhibitor of peptidyltransferase, the enzyme is responsible for the naturally occurring chloramphenicol resistance in bacteria. The enzyme, for which variants are known, is found in both gram-negative and gram-positive bacteria. EC flexneri: A bacterium which is one of the etiologic agents of bacillary dysentery (DYSENTERY, BACILLARY) and sometimes of infantile gastroenteritis.Precipitin Tests: 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.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Membrane Proteins: Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.Mitochondria: Semiautonomous, self-reproducing organelles that occur in the cytoplasm of all cells of most, but not all, eukaryotes. Each mitochondrion is surrounded by a double limiting membrane. The inner membrane is highly invaginated, and its projections are called cristae. Mitochondria are the sites of the reactions of oxidative phosphorylation, which result in the formation of ATP. They contain distinctive RIBOSOMES, transfer RNAs (RNA, TRANSFER); AMINO ACYL T RNA SYNTHETASES; and elongation and termination factors. Mitochondria depend upon genes within the nucleus of the cells in which they reside for many essential messenger RNAs (RNA, MESSENGER). Mitochondria are believed to have arisen from aerobic bacteria that established a symbiotic relationship with primitive protoeukaryotes. (King & Stansfield, A Dictionary of Genetics, 4th ed)Biological Transport: The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments.RNA, Small Nuclear: Short chains of RNA (100-300 nucleotides long) that are abundant in the nucleus and usually complexed with proteins in snRNPs (RIBONUCLEOPROTEINS, SMALL NUCLEAR). Many function in the processing of messenger RNA precursors. Others, the snoRNAs (RNA, SMALL NUCLEOLAR), are involved with the processing of ribosomal RNA precursors.Gene Expression: The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.DNA, Viral: Deoxyribonucleic acid that makes up the genetic material of viruses.Tumor Cells, Cultured: 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.Tissue Culture Techniques: A technique for maintaining or growing TISSUE in vitro, usually by DIFFUSION, perifusion, or PERFUSION. The tissue is cultured directly after removal from the host without being dispersed for cell culture.Regulatory Sequences, Nucleic Acid: Nucleic acid sequences involved in regulating the expression of genes.

The incorporation of 5-iodo-2'-deoxyuridine into the DNA of HeLa cells and the induction of alkaline phosphatase activity. (1/37241)

Inhibition of DNA synthesis during the period of exposure of HeLa cells to 5-iodo-2'-deoxyuridine (IUdR) inhibited the induction of alkaline phosphatase activity. This finding, taken together with previous findings that IUdR did not induce alkaline phosphatase activity in the presence of 2-fold molar excess thymidinemonstrated that IUdR incorporation into DNA is correlated with the increase in alkaline phosphatase activity. With the exception of an interim period described in the text, induction of alkaline phosphatase activity was linearly related to medium concentrations of IUdR of up to at least 3 muM. However, the extent of IUdR substitution in DNA did not appear to be related to the degree of enzyme induction. Alkaline phosphatase activity continued to increase at medium concentrations of IUdR from 1 to 3 muM, while little further substitution of DNA occurred.  (+info)

Stimulation of thymidine uptake and cell proliferation in mouse embryo fibroblasts by conditioned medium from mammary cells in culture. (2/37241)

Undialyzed conditioned medium from several cell culture sources did not stimulate thymidine incorporation or cell overgrowth in quiescent, density-inhibited mouse embryo fibroblast cells. However, dialyzed conditioned medium (DCM) from clonal mouse mammary cell lines MCG-V14, MCG-T14, MCG-T10; HeLa cells; primary mouse adenocarcinoma cells; and BALB/c normal mouse mammary epithelial cells promoted growth in quiescent fibroblasts. The amount of growth-promoting activity produced per cell varied from 24% (HeLa) to 213% (MCG-V14) of the activity produced by primary tumor cells. The production of growth-promoting activity was not unique to tumor-derived cells or cells of high tumorigenicity. The amount of growth-promoting activity produced per cell in the active cultures was not correlated with any of the following: tumorigenicity, growth rat, cell density achieved at saturation, cell type, or species of cell origin. It is concluded that transformed and non-transformed cells of diverse origin, cell type, and tumorigenicity can produce growth factors in culture. The growth-promoting potential of the active media from primary tumor cultures accumulated with time of contact with cells and was too great to be accounted for entirely by the removal of low-molecular-weight inhibitors by dialysis. The results are consistent with the hypothesis that conditioned medium from the active cultures contained a dialyzable, growth-promoting activity. Different cell lines exhibited differential sensitivity to tumor cell DCM and fetal bovine serum. Furthermore, quiescent fibroblasts were stimulated by primary tumor cell DCM in the presence of saturating concentrations of fetal bovine serum. These observations support the notion that the active growth-promoting principle in primary tumor cell DCM may not be a serum factor(s).  (+info)

Diphtheria toxin effects on human cells in tissue culture. (3/37241)

HeLa cells exposed to a single sublethal concentration of diphtheria toxin were found to have diminished sensitivity when subsequently reexposed to the toxin. Three cells strains exhibiting toxin resistance were developed. In the cells that had previously been exposed to toxin at 0.015 mug/ml, 50% inhibition of protein synthesis required a toxin concentration of 0.3 mug/ml, which is more than 10 times that required in normal HeLa cells. There appears to be a threshold level of diphtheria toxin action. Concentrations of toxin greater than that required for 50% inhibition of protein synthesis (0.01 mug/ml) are associated with cytotoxicity, whereas those below this concentration may not be lethal. Several established human cell lines of both normal and neoplastic origin were tested for their sensitivity to the effects of the toxin. No special sensitivity was observed with the cells of tumor origin. Fifty % inhibition of protein synthesis of HeLa cells was achieved with diphtheria toxin (0.01 mug/ml) as compared to the normal human cell lines tested (0.03 and 0.5 mug/ml) and a cell line derived from a human pancreatic adenocarcinoma (0.2 mug/ml). A human breast carcinoma cell line showed a maximum of 45% inhibition of protein synthesis. This required a diphtheria toxin concentration of 5 mug/ml. These results suggest that different human cell lines show wide variation in their sensitivity to the toxin.  (+info)

Evidence on the conformation of HeLa-cell 5.8S ribosomal ribonucleic acid from the reaction of specific cytidine residues with sodium bisulphite. (4/37241)

The reaction of HeLa-cell 5.8S rRNA with NaHSO3 under conditions in which exposed cytidine residues are deaminated to uridine was studied. It was possible to estimate the reactivities of most of the 46 cytidine residues in the nucleotide sequence by comparing 'fingerprints' of the bisulphite-treated RNA with those of untreated RNA. The findings were consistent with the main features of the secondary-structure model for mammalian 5.85S rRNA proposed by Nazar, Sitz, & Busch [J. Biol. Chem (1975) 250, 8591--8597]. Five out of six regions that are depicted in the model as single-stranded loops contain cytidine residues that are reactive towards bisulphite at 25 degrees C (the other loop contains no cytidine). The cytidine residue nearest to the 3'-terminus is also reactive. Several cytidines residues that are internally located within proposed double-helical regions show little or no reactivity towards bisulphite, but the cytidine residues of several C.G pairs at the ends of helical regions show some reactivity, and one of the proposed loops appears to contain six nucleotides, rather than the minimum of four suggested by the primary structure. Two cytidine residues that are thought to be 'looped out' by small helix imperfections also show some reactivity.  (+info)

Tyrosine phosphorylation is required for actin-based motility of vaccinia but not Listeria or Shigella. (5/37241)

Studies of the actin-based motility of pathogens have provided important insights into the events occurring at the leading edge of motile cells [1] [2] [3]. To date, several actin-cytoskeleton-associated proteins have been implicated in the motility of Listeria or Shigella: vasodilator-stimulated phosphoprotein (VASP), vinculin and the actin-related protein complex of Arp2 and Arp3 [4] [5] [6] [7]. To further investigate the underlying mechanism of actin-tail assembly, we examined the localization of components of the actin cytoskeleton including Arp3, VASP, vinculin and zyxin during vaccinia, Listeria and Shigella infections. The most striking difference between the systems was that a phosphotyrosine signal was observed only at the site of vaccinia actin-tail assembly. Micro-injection experiments demonstrated that a phosphotyrosine protein plays an important role in vaccinia actin-tail formation. In addition, we observed a phosphotyrosine signal on clathrin-coated vesicles that have associated actin-tail-like structures and on endogenous vesicles in Xenopus egg extracts which are able to nucleate actin tails [8] [9]. Our observations indicate that a host phosphotyrosine protein is required for the nucleation of actin filaments by vaccinia and suggest that this phosphoprotein might be associated with cellular membranes that can nucleate actin.  (+info)

Bcl-2 regulates amplification of caspase activation by cytochrome c. (6/37241)

Caspases, a family of specific proteases, have central roles in apoptosis [1]. Caspase activation in response to diverse apoptotic stimuli involves the relocalisation of cytochrome c from mitochondria to the cytoplasm where it stimulates the proteolytic processing of caspase precursors. Cytochrome c release is controlled by members of the Bcl-2 family of apoptosis regulators [2] [3]. The anti-apoptotic members Bcl-2 and Bcl-xL may also control caspase activation independently of cytochrome c relocalisation or may inhibit a positive feedback mechanism [4] [5] [6] [7]. Here, we investigate the role of Bcl-2 family proteins in the regulation of caspase activation using a model cell-free system. We found that Bcl-2 and Bcl-xL set a threshold in the amount of cytochrome c required to activate caspases, even in soluble extracts lacking mitochondria. Addition of dATP (which stimulates the procaspase-processing factor Apaf-1 [8] [9]) overcame inhibition of caspase activation by Bcl-2, but did not prevent the control of cytochrome c release from mitochondria by Bcl-2. Cytochrome c release was accelerated by active caspase-3 and this positive feedback was negatively regulated by Bcl-2. These results provide evidence for a mechanism to amplify caspase activation that is suppressed at several distinct steps by Bcl-2, even after cytochrome c is released from mitochondria.  (+info)

The splicing factor-associated protein, p32, regulates RNA splicing by inhibiting ASF/SF2 RNA binding and phosphorylation. (7/37241)

The cellular protein p32 was isolated originally as a protein tightly associated with the essential splicing factor ASF/SF2 during its purification from HeLa cells. ASF/SF2 is a member of the SR family of splicing factors, which stimulate constitutive splicing and regulate alternative RNA splicing in a positive or negative fashion, depending on where on the pre-mRNA they bind. Here we present evidence that p32 interacts with ASF/SF2 and SRp30c, another member of the SR protein family. We further show that p32 inhibits ASF/SF2 function as both a splicing enhancer and splicing repressor protein by preventing stable ASF/SF2 interaction with RNA, but p32 does not block SRp30c function. ASF/SF2 is highly phosphorylated in vivo, a modification required for stable RNA binding and protein-protein interaction during spliceosome formation, and this phosphorylation, either through HeLa nuclear extracts or through specific SR protein kinases, is inhibited by p32. Our results suggest that p32 functions as an ASF/SF2 inhibitory factor, regulating ASF/SF2 RNA binding and phosphorylation. These findings place p32 into a new group of proteins that control RNA splicing by sequestering an essential RNA splicing factor into an inhibitory complex.  (+info)

The amino-terminal C/H1 domain of CREB binding protein mediates zta transcriptional activation of latent Epstein-Barr virus. (8/37241)

Latent Epstein-Barr virus (EBV) is maintained as a nucleosome-covered episome that can be transcriptionally activated by overexpression of the viral immediate-early protein, Zta. We show here that reactivation of latent EBV by Zta can be significantly enhanced by coexpression of the cellular coactivators CREB binding protein (CBP) and p300. A stable complex containing both Zta and CBP could be isolated from lytically stimulated, but not latently infected RAJI nuclear extracts. Zta-mediated viral reactivation and transcriptional activation were both significantly inhibited by coexpression of the E1A 12S protein but not by an N-terminal deletion mutation of E1A (E1ADelta2-36), which fails to bind CBP. Zta bound directly to two related cysteine- and histidine-rich domains of CBP, referred to as C/H1 and C/H3. These domains both interacted specifically with the transcriptional activation domain of Zta in an electrophoretic mobility shift assay. Interestingly, we found that the C/H3 domain was a potent dominant negative inhibitor of Zta transcriptional activation function. In contrast, an amino-terminal fragment containing the C/H1 domain was sufficient for coactivation of Zta transcription and viral reactivation function. Thus, CBP can stimulate the transcription of latent EBV in a histone acetyltransferase-independent manner mediated by the CBP amino-terminal C/H1-containing domain. We propose that CBP may regulate aspects of EBV latency and reactivation by integrating cellular signals mediated by competitive interactions between C/H1, C/H3, and the Zta activation domain.  (+info)

  • 2019). Lastly, RanBPM has been linked to various signaling pathways related to numerous cellular processes which include - apoptosis, cell adhesion, migration, transcription, nuclear-cytoplasmic transport and also plays a significant role during development (Salemi et al. (worldiscoveries.ca)
  • these 3 three findings were thought sufficient to define a cell line as HeLa. (thefreedictionary.com)
  • DNA extracted from a SiHa cell line was used as the positive control for HPV16, whereas DNA extracted from a HeLa cell line was used as the positive control for consensus primers and for HPV18-specific primers. (thefreedictionary.com)
  • Researchers at Western University have developed stable RanBPM shRNA HeLa cell line as a research tool. (worldiscoveries.ca)
  • The RanBPM shRNA expressing stable cell line has been validated and displays complete depletion/knockdown of RanBPM (Figure 3D, McTavish et al. (worldiscoveries.ca)
  • The current cell line serves as an excellent reagent or tool to study the functional role of RanBPM in different cellular processes. (worldiscoveries.ca)
  • Recent genomic sequencing on the popular 'Kyoto' HeLa line reveals known errors common to cancer cells like extra copies of certain chromosomes, but also shows unexpected mutations like strong expression of certain genes and segment reshuffling on many chromosomes. (freethoughtblogs.com)
  • Cells cultures of CHO (Chinese Hamster Ovary), EL4 (Mouse T Lymphocyte Cell Line), SF9 (Ovarian tissue from Spodoptera frugiperda ) insect cells and of HELA cells were used to assess the effects of long analysis durations and different sample preparation conditions on different types of cells. (mybeckman.in)
  • Following selection, a panel of validation assays designed to evaluate the effects of nuclear label expression on functional cell biology was completed. (essenbioscience.com)
  • A lot of important points have been raised by other commenters, the most important of which is that everybody already knew that these cells were not genetically normal and despite that, they have enabled absolutely revolutionary discoveries in biology. (freethoughtblogs.com)
  • The quantitative study of cell morphology is of great importance as the structure and condition of cells and their structures can be related to conditions of health or disease. (crick.ac.uk)
  • Therefore, we used H2 ER [alpha]-GFP transfected into HeLa cells to test D3 binding by visualizing that D3 increases the translocation of ER [alpha] to the nucleus. (thefreedictionary.com)
  • Each vial contains a stable population of 1 million HeLa cells expressing the NucLight Red fluorescent protein restricted to the nucleus. (essenbioscience.com)
  • Centrifugation and resuspension are routine methods for washing and concentrating cells ahead of reseeding or use in other experiments. (mybeckman.in)
  • HeLa cells have been used extensively around the world in many different fields of research including cancer research, immunology and vaccine development. (wellcomecollection.org)
  • Readers learn not just about HeLa cells and John Moore but also about the development of polio vaccine, HIPAA, the Jewish Chronic Disease Hospital cancer studies, and the history of Johns Hopkins hospital. (thefreedictionary.com)
  • Images of a HeLa cancer cell were semantically segmented with one traditional image-processing algorithm and four three deep learning architectures: VGG16, ResNet18, Inception-ResNet-v2, and U-Net. (crick.ac.uk)
  • However, the role of circRNAs in cervical cancer and the radioresistance mechanisms of HeLa cells are unknown. (peerj.com)
  • HeLa cells were isolated from a cancer. (freethoughtblogs.com)
  • Cancer cells have these common features, like genomic instability, aneuploidies, and loss of cell cycle control that we all know about. (freethoughtblogs.com)
  • High-throughput sequencing and bioinformatics analysis of irradiated and sham-irradiated HeLa cells. (peerj.com)
  • Beckman Coulter Life Sciences is proud to introduce our new Vi-CELL BLU Cell Viability Analyzer . (mybeckman.in)
  • However this requires approximately 3 hours to run the entire plate with may not be ideal, particularly for cell types that generally have low viability or are prone deterioration once outside the incubator or bioreactor. (mybeckman.in)
  • However resuspension in PBS buffer results in a drastic loss of viability and significant reduction in average cell diameter. (mybeckman.in)
  • Attachment of DNA to the nucleoskeleton of HeLa cells examined using physiological conditions. (ox.ac.uk)
  • HeLa cells are encapsulated in agarose microbeads and lysed using Triton in a 'physiological' buffer. (ox.ac.uk)
  • Under UV light irradiation, the TiO 2 nanofibers, particularly the mixed phase nanofibers, displayed much higher cell-killing efficiency than Pirarubicin (THP), which is a common drug to induce the apoptosis of HeLa cells. (springer.com)
  • Chronically infected cultures of HeLa cells were also established that may be a useful tool for studying long-term interactions between virulent L. pneumophila and mammalian cells. (nih.gov)
  • One of the earliest variants, known as enhanced green fluorescence protein ( EGFP ), contains codon substitutions (commonly referred to as the S65T mutation) that alleviates the temperature sensitivity and increases the efficiency of GFP expression in mammalian cells. (fsu.edu)
  • Cherepanova NA, Gilmore R. Mammalian cells lacking either the cotranslational or posttranslocational oligosaccharyltransferase complex display substrate-dependent defects in asparagine linked glycosylation. (umassmed.edu)
  • No. 5,464,768,"Enhanced nitrite production in transfected murine cells", issued Nov. 7, 1995 to Kiel et al, describes mammalian cells line capable of enhanced nitrite production prepared by transfecting a murine macrophage or murinethymoma with barley nitrate reductase gene (NR). The cell lines can be used for the production of diazomelanin (DM) and diazoluminomelanin (DALM). (patentgenius.com)
  • These experiments firmly established the capability of this proteomics technology to enable comprehensively analysis of any mammalian cell or tissue proteome in a quantitative manner with sufficient throughput for clinical applications with larger patient cohorts. (ku.dk)
  • Here we describe a simple method to demonstrate the genotoxicity of bacteria producing colibactin following a short infection of cultured mammalian cells with pks + E. coli . (bio-protocol.org)
  • Thus, to demonstrate the genotoxicity of colibactin producing E. coli , cultured mammalian cells (such as HeLa cells) are infected during 4 h with live pks + bacteria. (bio-protocol.org)
  • All of the body's normal cells experience the effects of aging over time, known as cellular senescence . (howstuffworks.com)
  • This is called programmed cell death ( PCD ), apoptosis or even cellular suicide . (howstuffworks.com)
  • This MOA was also confirmed experimentally: the cyano-substituted heteroaryles disrupted the actin and the tubulin networks in HeLa cells and inhibited cellular migration. (springer.com)
  • The cell cycle is a universal process during which, through a series of cellular events, single cell gives rise to two daughter individuals. (nature.com)
  • At the individual cell level, the electrical properties of the cell are helpful for understanding the effects of cellular behavior. (hindawi.com)
  • Decreased expression of unknown genes in tumorigenic compared to non-tumorigenic cells, including EFEMP2, a cellular gene located on chromosome 11q13. (aacrjournals.org)
  • Macroautophagy (called just autophagy hereafter) is an intracellular degradation machinery essential for cell survival under stress conditions and for the maintenance of cellular homeostasis. (csic.es)
  • These findings suggest that the increased NADH fluorescence lifetime in STS-induced cell death occurred before the depletion of ΔΨ and ATP and activation of caspase 3, and was not simply caused by cellular metabolic change. (spiedigitallibrary.org)
  • Overall, this study suggests the absence of one or more cellular factors in HeLa cells that results in abortive replication of H1N1, H3N2, and LPAI viruses, but can be circumvented upon introduction of H5N1 NP and HA. (asm.org)
  • HeLa is the most widely used model cell line for studying human cellular and molecular biology. (g3journal.org)
  • The present results indicated that activation of the Wnt/β‑catenin signaling pathway by HLY78 reduced 12C6+ radiation‑induced HeLa cell dysfunction, suggesting that the Wnt/β‑catenin signaling pathway plays an important role in regulating 12C6+ radiation‑induced cellular toxicity in HeLa cells. (spandidos-publications.com)
  • this cellular heterogeneity was not related in any obvious way to cell-cycle-dependent changes. (biologists.org)
  • 2013). The microscopic observation of the cell morphology reveals the cellular response to the genotoxic insult, with reduced cell numbers and a striking giant cells phenotype (called megalocytosis) due to the cell cycle arrest and cellular senescence. (bio-protocol.org)
  • Fluorescence micrograph of a HeLa cell (human cervical cancer cell), showing the cytoskeletal microfilaments (actin, red), and nuclei stain with Hoechst (DNA, blue), X1500 (at 13 x 17 in. (sciencephoto.com)
  • In addition, the cells were labeled for filamentous actin with Alexa Fluor 568 conjugated to phalloidin, and for nuclear DNA with the ultraviolet-absorbing probe DAPI. (fsu.edu)
  • Multiphoton fluorescence image of HeLa cells stained with the actin binding toxin phalloidin (red), microtubules (cyan) and cell nuclei (blue). (technologynetworks.com)
  • Increased expression of unknown genes in tumorigenic compared to non-tumorigenic hybrid cells: eg. (aacrjournals.org)
  • From 12-96 hours post irradiation a significant fraction of the genes with altered expression were found to be involved in cell cycle progression and its regulation. (diva-portal.org)
  • 8, These findings suggest that cytoplasmic genes may have a wider role in the cell than hitherto suspected and may direct a considerable fraction of mRNA and protein synthesis. (caltech.edu)
  • The authors established the protein copy numbers of 12,209 protein-coding genes in HeLa cells, which is comparable to the coverage of the achieved by next-generation RNA-Seq technology. (ku.dk)
  • We sought to identify genes involved in the control of adherence of EHEC O157:H7 to cultured epithelial cells. (asm.org)
  • It is challenging to determine why, from the multiple regions in the EHEC O157:H7 chromosome with a putative role in adherence, only a limited number of genes within the LEE and other loci have been suggested to be involved in the adherence of these organisms to host cells. (asm.org)
  • To study the cell type specificity of the direction of replication of the human c-myc genes and the relationship of replication polarity to transcriptional activity, we analyzed the directions of replication of the c-myc genes in two Burkitt lymphoma cell lines, CA46 and ST486, and in HeLa cells. (asm.org)
  • In contrast, the transcribed c-myc genes of CA46 cells were replicated in the transcriptional direction, while the translocated, amplified c-myc genes of ST486 cells showed no preferred polarity of replication. (asm.org)
  • The data also provided evidence for the existence of an endogenous barrier to DNA polymerases in the flanking DNA immediately 5' to the HeLa c-myc genes. (asm.org)
  • The ImageXpress® Pico system does more than imaging-it offers unparalleled analysis capabilities that simplifies image analysis for cell-based assays. (moleculardevices.com)
  • By complement fixation assays, the antisera reacted with HeLa cell chromatin but only marginally with human placenta chromatin. (aacrjournals.org)
  • These cells are used for VIRUS CULTIVATION and antitumor drug screening assays. (umassmed.edu)
  • A Travelling Fellowship from Journal of Cell Science allowed her to spend time in Prof Maddy Parson's lab at King's College London, learning new cell migration assays and analysing fibroblasts cultured from individuals with Parkinson's. (biologists.org)
  • Caspase-3, Neutral red and DNA fragmentation assays were carried out on HeLa cell lines cultured in Dulbecco s Modified Eagles Medium (DMEM) in (95% O 2 + 5% CO 2 ) at 35°C. The apoptotic, cytotoxic capacities and DNA fragmentation assays were carried out on the medicinal plant s. (scialert.net)
  • Using M13mp2 DNA containing the simian virus 40 (SV40) origin of replication and a plus-one frameshift mutation in the lacZ alpha reporter gene, we performed replication reactions using a HeLa cell extract and the SV40 large T antigen. (nih.gov)
  • Materials and Methods: Differential gene expression patterns were analysed in non-tumorigenic and tumorigenic hybrid cells, parental HeLa cells and normal human fibroblasts by microarray analysis using Hu133Plus2.0 chips by Affymetrix. (aacrjournals.org)
  • Conclusion: Differential gene expression of a so far unknown gene on chromosome 11q13 may play a central role in determination for in vivo growth potential of non-tumorigenic and tumorigenic HeLa x fibroblast hybrid cells. (aacrjournals.org)
  • Furthermore, biological responses linked to mitotic catastrophe including cell cycle arrests, anaphase bridge formation and centrosome amplification were analyzed and correlation to gene expression changes evaluated. (diva-portal.org)
  • This study elucidates specific characteristics in the altered gene expression pattern induced by irradiation, which can be linked to the sequential steps observed in HeLa Hep2 cells during mitotic catastrophes. (diva-portal.org)
  • Previous attempts to transfect human cells with a functional nitrate reductase gene have not, until now, been successful. (patentgenius.com)
  • Accordingly, it is an object of the present invention to provide a human carcinoma cell modified with a nitrate reductase gene fragment. (patentgenius.com)
  • Disruption of the ompA gene in the tdcA mutant strain abolished the hyperadherent phenotype, and anti-OmpA serum inhibited adhesion of wild-type and tdcA mutant strains to HeLa cells. (asm.org)
  • Our analysis of the HeLa gene expression profile revealed that several pathways, including cell cycle and DNA repair, exhibit significantly different expression patterns from those in normal human tissues. (g3journal.org)
  • Nucleoporin levels regulate cell cycle progression and phase-specific gene expression. (harvard.edu)
  • The HeLa carcinoma cell culture featured in the digital image above was transfected with an EGFP-peroxisomal targeting signal 1 (PTS1) fusion protein and stained with MitoTracker Red CMXRos. (fsu.edu)
  • This leads to the publication of scientific articles in which the authors report what they believe to be their findings on skin cancer in humans, whereas their assumptions were based on studying mouse cells. (eurekalert.org)
  • In humans Bub1 accumulates gradually during G1 and S phase of the cell cycle, peaks at G2/M, and drops dramatically after mitosis. (wikipedia.org)
  • Treatment with the plant extract showed distribution of cells between late apoptotic and necrotic phases and caused cell cycle arrest at the G0/G1 phase. (omicsonline.org)
  • Results demonstrated that R. arboreum could be a potential anti-cancer agent by its mechanism of inducing apoptotic cell death and cell cycle arrest in HeLa cells. (omicsonline.org)
  • Exposure of HeLa cells to 40 μmol/L of tubeimoside induced nuclear shrinkage,chromation condensation and margination against nuclear envelope,subdiploid peak,and DNA fragmentation, characteristic as seen in apoptotic cells. (cnki.com.cn)
  • HeLa cells dividing under electron microscopy. (howstuffworks.com)
  • These strategies were compared through the semantic segmentation of the nucleus, nuclear envelope, cell and background of three hundred slices of a HeLa cell observed with electron microscopy. (eurekalert.org)
  • In this work, ultrastructure changes caused by the action of two 2nd generation photosensitizers and laser irradiation on CHO-K1 and HeLa (neoplastic) cells were analyzed by transmission electron microscopy. (sigmaaldrich.com)
  • Electron microscopy of thin sections of material treated by this method has revealed that all mitochondrial profiles within a cell (and only these) are stained and they exhibit a well preserved size and internal structure. (biologists.org)
  • The bacteria contained in the isolated mature vesicles had a unique envelope structure and were highly adherent to HeLa cells, characteristics that correlated with a bright red appearance after the Giménez stain (Giménez positive). (nih.gov)
  • RNA·DNA hybridization experiments utilizing separated strands of HeLa mitochondrial DNA and mit-RNA from HeLa cells exposed to short pulses of [5-3H]uridine have shown that the labeled RNA hybridizes with both the light (L) and the heavy (H) strand, though to a different relative extent depending upon the labeling time. (caltech.edu)
  • These observations and the previous evidence of complete transcription of the H strand strongly suggest that mit-DNA is transcribed in HeLa cells symmetrically over a considerable portion of its length, with the transcript of the L strand being rapidly degraded or otherwise removed from the mitochondrial fraction. (caltech.edu)
  • This observation indicates that in a large proportion of HeLa F-315 cells, at least under the growth conditions used here, the mitochondrial complement is dividied into distinct organelles. (biologists.org)
  • Intracellular replication of virulent L. pneumophila took place in ribosome-studded complex endosomes and led to the formation of free bacteria-laden vesicles presumably released from lysed HeLa cells. (nih.gov)
  • It is concluded that reversal by polyamines of the deficiency in S-phase DNA synthesis, in polyamine-depleted HeLa cells, is a time-dependent process indicative of the necessity for the replenishment of replication factors or their organization into an active replication complex. (biochemj.org)
  • Efficient replication of IAV in different species is, in part, dictated by its ability to exploit the genetic environment of the host cell. (asm.org)
  • To investigate IAV tropism in human cells, we evaluated the replication of IAV strains in a diverse subset of epithelial cell lines. (asm.org)
  • Heterokaryon cells generated by fusion of HeLa and permissive cells supported H1N1 growth, suggesting the absence of a host factor(s) required for replication of H1N1, but not H5N1, in HeLa cells. (asm.org)
  • For decades, immortal cells such as the famous HeLa cells have been contaminating other cell cultures in the lab. (eurekalert.org)
  • Unfortunately, HeLa cells have been contaminating other cell cultures for decades. (eurekalert.org)
  • Due to, for instance, carelessness in the lab these rapidly reproducing cells began taking over other cell cultures. (eurekalert.org)
  • Large amounts of cell cultures have therefore been mislabelled. (eurekalert.org)
  • Various initiatives have been developed over the years to prevent the exchange of cell cultures, such as better protocols and hygienic fume cupboards. (eurekalert.org)
  • When investigated with double whole-cell patch-clamp measurements, HeLa cells in monolayer cultures were electrically coupled in 39% of the cases with very low transjunctional conductances (average one to five open channels). (uni-stuttgart.de)
  • A comparison was made of the polyamine content and S-phase DNA synthesis in cells from control cultures and cultures to which an inhibitor of polyamine biosynthesis, alpha-difluoromethylornithine, was added to the synchronization medium. (biochemj.org)
  • Almost complete restoration of DNA synthesis in cells depleted of polyamines was achieved by the addition of a polyamine to cultures at least 10 h before release of the second thymidine block. (biochemj.org)
  • A HeLa cell culture production laboratory was set up at Tuskegee University, which at its peak was shipping in the region of 20,000 tube cultures per week. (technologynetworks.com)
  • After Gartler's discovery that HeLa cells could travel through the air and contaminate other cultures, vast improvements were made to cell culture practices, to prevent further costly cross-contaminations. (technologynetworks.com)
  • Coverslip cultures of synchronized and unsynchronized HeLa (F-315) cells stained with the DAB reaction were examined under oil immersion. (biologists.org)
  • HeLa cells have a modal chromosome number of 82, with 4 copies of chromosome 12 and 3 copies of chromosomes 6, 8, and 17. (abcam.com)
  • Recently, two Nobel prizes have been awarded for discoveries where HeLa cells played a central role, namely the link between human papilloma virus and cervical cancer (2008, Harald zur Hausen) and the role of telomerase in preventing chromosome degradation (2011, Elizabeth Blackburn, Carol Greider, and Jack Szostak). (g3journal.org)
  • The protein kinase Bub1 possesses versatile and distinct functions during the cell cycle, mainly in the SAC and chromosome alignment during metaphase. (wikipedia.org)
  • Enhanced adhesion mediated by OmpA was also observed with Caco-2 cells, and anti-OmpA serum blocked adherence to HeLa cells of other EHEC O157:H7 strains. (asm.org)
  • We recently characterized a fimbrial operon in EHEC O157:H7 that mediates adherence when introduced into a nonfimbriated E. coli K-12 strain, but EHEC strains mutated in this operon were only modestly reduced in adherence to HeLa cells ( 39 ). (asm.org)
  • Since we had determined that TLR4 was present in cervical tissues and could therefore mediate inflammatory signalling in the cervical mucosa, we next investigated the impact of LPS stimulation on HIV receptor expression in cervical epithelial cells, using HeLa cells as a model system. (thefreedictionary.com)
  • The technology has been streamlined for one day mass spectrometric measurements of human proteomes from cells and tissues. (ku.dk)
  • The diaminobenzidine (DAB) technique for the ultrastructural localization of sites of cytochrome c oxidase activity in animal tissues has been adapted to the visualization of mitochondria in animal cells growing in culture. (biologists.org)
  • As a result, nanoviscosity affects all diffusion-based interactions in living cell, including biosynthesis, signalling pathways or even active transport 5 . (nature.com)
  • It is also found that functionalized disc-shaped zeolite L particles enter the cancer cells via different, partly not yet characterized, pathways. (wiley.com)
  • EHEC O157:H7 also harbor a large pathogenicity island, termed the locus for enterocyte effacement (LEE), which is associated with the intimate adherence to epithelial cells, initiation of host signal transduction pathways, and the formation of attaching-and-effacing intestinal lesions (reviewed in references 16 and 40 ). (asm.org)
  • Here, we describe an optimized protocol for the analysis of relevant parameters of autophagic fl ux using HeLa cells stably expressing EGFP-LC3. (csic.es)
  • With excellent optical properties, quantum dots (QDs) have been made as attractive molecular probes for labelling cells in biological research. (biomedsearch.com)
  • Once the killer cell has killed some of the HeLa cells, the killer cell is gently detached from the HeLa layer with the CellEctor microcapillary for subsequent molecular analysis. (selectscience.net)
  • 1 Laboratory of Molecular and Cell Genetics, Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, People's Republic of China. (nih.gov)
  • Effective design and interpretation of molecular genetic studies performed using HeLa cells require accurate genomic information. (g3journal.org)
  • And to solve that problem, you either have to reduce the pressure to publish or require all researchers to carry out a genetic test before working with the cells. (eurekalert.org)