A group of compounds containing the porphin structure, four pyrrole rings connected by methine bridges in a cyclic configuration to which a variety of side chains are attached. The nature of the side chain is indicated by a prefix, as uroporphyrin, hematoporphyrin, etc. The porphyrins, in combination with iron, form the heme component in biologically significant compounds such as hemoglobin and myoglobin.
Oncogene Proteins v-sis
Oncogene Protein tpr-met
The GENETIC TRANSLATION product from a GENE FUSION between a sequence from the tpr protein gene on the human CHROMOSOME 1 and the gene for PROTO-ONCOGENE PROTEINS C-MET.
Oncogene Protein v-maf
An oncogene protein that was originally isolated from a spontaneous musculo-aponeurotic FIBROSARCOMA in CHICKEN and shown to be the transforming gene of the avian retrovirus AS42. It is a basic leucine zipper TRANSCRIPTION FACTOR and the founding member of the MAF TRANSCRIPTION FACTORS.
Oncogene Protein gp140(v-fms)
Transforming glycoprotein coded by the fms oncogene from the Susan McDonough strain of feline sarcoma virus (SM-FeSV). The oncogene protein v-fms lacks sequences, which, in the highly homologous proto-oncogene protein c-fms (CSF-1 receptor), normally serve to regulate its tyrosine kinase activity. The missing sequences in v-fms mimic the effect of ligand and lead to constitutive cell growth. The protein gp120(v-fms) is post-translationally modified to generate gp140(v-fms).
Oncogene Proteins v-mos
Transforming proteins coded by mos oncogenes. The v-mos proteins were originally isolated from the Moloney murine sarcoma virus (Mo-MSV).
Oncogene Protein p55(v-myc)
Transforming protein coded by myc oncogenes. The v-myc protein has been found in several replication-defective avian retrovirus isolates which induce a broad spectrum of malignancies.
Oncogene Protein p65(gag-jun)
Transforming protein coded by jun oncogenes (GENES, JUN). This is a gag-onc fusion protein of about 65 kDa derived from avian sarcoma virus. v-jun lacks a negative regulatory domain that regulates transcription in c-jun.
Oncogene Proteins v-raf
Oncogene Proteins v-fos
Transforming proteins coded by fos oncogenes. These proteins have been found in the Finkel-Biskis-Jinkins (FBJ-MSV) and Finkel-Biskis-Reilly (FBR-MSV) murine sarcoma viruses which induce osteogenic sarcomas in mice. The FBJ-MSV v-fos gene encodes a p55-kDa protein and the FBR-MSV v-fos gene encodes a p75-kDa fusion protein.
Oncogene Protein v-crk
Oncogene Proteins v-myb
Transforming proteins coded by myb oncogenes. Transformation of cells by v-myb in conjunction with v-ets is seen in the avian E26 leukemia virus.
Oncogene Protein v-cbl
Oncogene Proteins v-erbB
Transforming proteins encoded by erbB oncogenes from the avian erythroblastosis virus. The protein is a truncated form of the EGF receptor (RECEPTOR, EPIDERMAL GROWTH FACTOR) whose kinase domain is constitutively activated by deletion of the ligand-binding domain.
Oncogene Proteins v-abl
Transforming proteins encoded by the abl oncogenes. Oncogenic transformation of c-abl to v-abl occurs by insertional activation that results in deletions of specific N-terminal amino acids.
Genes whose gain-of-function alterations lead to NEOPLASTIC CELL TRANSFORMATION. They include, for example, genes for activators or stimulators of CELL PROLIFERATION such as growth factors, growth factor receptors, protein kinases, signal transducers, nuclear phosphoproteins, and transcription factors. A prefix of "v-" before oncogene symbols indicates oncogenes captured and transmitted by RETROVIRUSES; the prefix "c-" before the gene symbol of an oncogene indicates it is the cellular homolog (PROTO-ONCOGENES) of a v-oncogene.
Oncogene Proteins v-rel
Transforming proteins coded by rel oncogenes. The v-rel protein competes with rel-related proteins and probably transforms cells by acting as a dominant negative version of c-rel. This results in the induction of a broad range of leukemias and lymphomas.
Oncogene Proteins v-erbA
Transforming proteins encoded by erbA oncogenes from the avian erythroblastosis virus. They are truncated versions of c-erbA, the thyroid hormone receptor (RECEPTORS, THYROID HORMONE) that have retained both the DNA-binding and hormone-binding domains. Mutations in the hormone-binding domains abolish the transcriptional activation function. v-erbA acts as a dominant repressor of c-erbA, inducing transformation by disinhibiting proliferation.
Oncogene Protein p21(ras)
Transforming protein encoded by ras oncogenes. Point mutations in the cellular ras gene (c-ras) can also result in a mutant p21 protein that can transform mammalian cells. Oncogene protein p21(ras) has been directly implicated in human neoplasms, perhaps accounting for as much as 15-20% of all human tumors. This enzyme was formerly listed as EC 220.127.116.11.
Oncogene Protein pp60(v-src)
A tyrosine-specific protein kinase encoded by the v-src oncogene of ROUS SARCOMA VIRUS. The transforming activity of pp60(v-src) depends on both the lack of a critical carboxy-terminal tyrosine phosphorylation site at position 527, and the attachment of pp60(v-src) to the plasma membrane which is accomplished by myristylation of its N-terminal glycine.
Oncogene Proteins, Viral
Oncogene Proteins, Fusion
Family of retrovirus-associated DNA sequences (ras) originally isolated from Harvey (H-ras, Ha-ras, rasH) and Kirsten (K-ras, Ki-ras, rasK) murine sarcoma viruses. Ras genes are widely conserved among animal species and sequences corresponding to both H-ras and K-ras genes have been detected in human, avian, murine, and non-vertebrate genomes. The closely related N-ras gene has been detected in human neuroblastoma and sarcoma cell lines. All genes of the family have a similar exon-intron structure and each encodes a p21 protein.
Oncogene Protein v-akt
A viral oncoprotein originally isolated from a murine T CELL LYMPHOMA infected with the acutely transforming retrovirus AKT8. v-akt protein is the viral homologue of PROTO-ONCOGENE PROTEINS C-AKT.
Cell Transformation, Neoplastic
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.
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.
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.
Proto-Oncogene Proteins c-myc
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.
Proto-Oncogene Proteins p21(ras)
Cellular proteins encoded by the H-ras, K-ras and N-ras genes. The proteins have GTPase activity and are involved in signal transduction as monomeric GTP-binding proteins. Elevated levels of p21 c-ras have been associated with neoplasia. This enzyme was formerly listed as EC 18.104.22.168.
Gene Expression Regulation, Neoplastic
Retroviridae Proteins, Oncogenic
Cell Transformation, Viral
An inheritable change in cells manifested by changes in cell division and growth and alterations in cell surface properties. It is induced by infection with a transforming virus.
Cell Line, Transformed
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.
Cell Line, Tumor
A cell line derived from cultured tumor cells.
The erbB-2 gene is a proto-oncogene that codes for the erbB-2 receptor (RECEPTOR, ERBB-2), a protein with structural features similar to the epidermal growth factor receptor. Its name originates from the viral oncogene homolog (v-erbB) which is a truncated form of the chicken erbB gene found in the avian erythroblastosis virus. Overexpression and amplification of the gene is associated with a significant number of adenocarcinomas. The human c-erbB-2 gene is located at 17q21.2.
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.
Small, monomeric GTP-binding proteins encoded by ras genes (GENES, RAS). The protooncogene-derived protein, PROTO-ONCOGENE PROTEIN P21(RAS), plays a role in normal cellular growth, differentiation and development. The oncogene-derived protein (ONCOGENE PROTEIN P21(RAS)) can play a role in aberrant cellular regulation during neoplastic cell transformation (CELL TRANSFORMATION, NEOPLASTIC). This enzyme was formerly listed as EC 22.214.171.124.
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.
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 cell surface protein-tyrosine kinase receptor that is overexpressed in a variety of ADENOCARCINOMAS. It has extensive homology to and heterodimerizes with the EGF RECEPTOR, the ERBB-3 RECEPTOR, and the ERBB-4 RECEPTOR. Activation of the erbB-2 receptor occurs through heterodimer formation with a ligand-bound erbB receptor family member.
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.
Gene Expression Regulation
Family of RNA viruses that infects birds and mammals and encodes the enzyme reverse transcriptase. The family contains seven genera: DELTARETROVIRUS; LENTIVIRUS; RETROVIRUSES TYPE B, MAMMALIAN; ALPHARETROVIRUS; GAMMARETROVIRUS; RETROVIRUSES TYPE D; and SPUMAVIRUS. A key feature of retrovirus biology is the synthesis of a DNA copy of the genome which is integrated into cellular DNA. After integration it is sometimes not expressed but maintained in a latent state (PROVIRUSES).
Tumor Suppressor Protein p53
Amino Acid Sequence
The GENETIC RECOMBINATION of the parts of two or more GENES, including an ONCOGENE as at least one of the fusion partners. Such gene fusions are often detected in neoplastic cells and are transcribed into ONCOGENE FUSION PROTEINS.
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.
All of the processes involved in increasing CELL NUMBER including CELL DIVISION.
Retrovirus-associated DNA sequences (src) originally isolated from the Rous sarcoma virus (RSV). The proto-oncogene src (c-src) codes for a protein that is a member of the tyrosine kinase family and was the first proto-oncogene identified in the human genome. The human c-src gene is located at 20q12-13 on the long arm of chromosome 20.
Sarcoma Viruses, Murine
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.
Avian leukosis virus
Promoter Regions, Genetic
Fusion Proteins, bcr-abl
Translation products of a fusion gene derived from CHROMOSOMAL TRANSLOCATION of C-ABL GENES to the genetic locus of the breakpoint cluster region gene on chromosome 22. Several different variants of the bcr-abl fusion proteins occur depending upon the precise location of the chromosomal breakpoint. These variants can be associated with distinct subtypes of leukemias such as PRECURSOR CELL LYMPHOBLASTIC LEUKEMIA-LYMPHOMA; LEUKEMIA, MYELOGENOUS, CHRONIC, BCR-ABL POSITIVE; and NEUTROPHILIC LEUKEMIA, CHRONIC.
Harvey murine sarcoma virus
A replication-defective mouse sarcoma virus (SARCOMA VIRUSES, MURINE) first described by J.J. Harvey in 1964.
Adenovirus E1A Proteins
Antigens, Polyomavirus Transforming
Polyomavirus antigens which cause infection and cellular transformation. The large T antigen is necessary for the initiation of viral DNA synthesis, repression of transcription of the early region and is responsible in conjunction with the middle T antigen for the transformation of primary cells. Small T antigen is necessary for the completion of the productive infection cycle.