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Cancer. Oncogenes Tumor Supressor Genes DNA Repair Genes. Oncogenes and Cancer. An oncogene is a gene that has sustained some genetic damage and, therefore, produces a protein capable of cellular transformation. An oncogene can be in the cellular or viral form.
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Cancer Oncogenes Tumor Supressor Genes DNA Repair Genes
Oncogenes and Cancer • An oncogene is a gene that has sustained some genetic damage and, therefore, produces a protein capable of cellular transformation. • An oncogene can be in the cellular or viral form. • Extensive, unrestricted gene expression is the cause of cancer.
Oncogene Cancer Examples • Mutations in the p53 gene cause Li-Fraumeni Syndrome and OMIM data syndrome which leads to brain tumors, sarcomas, leukemia, and breast cancer. This mutation affects cell cycle regulation. • Mutations in the WT1 gene cause Wilms Tumor syndrome which leads to pediatric kidney cancer. Transcriptional regulation is affected by the mutation of the WT1 gene.
DNA Repair Genes and Cancer • These are genes tat ensure that each strand of genetic information is accurately copied during cell division in the cell cycle. • Mutations in the DNA repair genes leads to an increase in the frequency of other mutations
DNA Repair Gene Cancer Examples • These disorders have a variety of cancer associated with them: • Bloom’s syndrome • Ataxia telangiectasia • Fanconi anemia • Xeroderma pigmentosum
Tumor Suppressor Genes • Tumor suppressor genes normally function to inhibit or "put the brakes on" the cell growth and division cycle • They function to prevent the development of tumors. • Mutations in tumor suppressor genes cause the cell to ignore one or more of the components of the network of inhibitory signals, removing the brakes from the cell cycle and resulting in a higher rate of uncontrolled growth of cancer.
The p53 Tumor Suppressor Gene Figure 1: Structural features of the p53 tumor suppressor gene. The transcriptionactivation site (TAS), heat shock protein binding site (HSP), SV40 large T-antigen binding sites (SV40), adenovirus E1b and papillomavirus E6 binding sites, cellular Mdm2 binding site, nuclear localization signal (NLS), oligmerization domain (OLIGO) and phosphorylation sites (cdc2 and CDK). The five evolutionarily conserved domains are labeled HCD I - V and the hot spot regions are HSR A - D.