oncogenes_flashcards
What are oncogenes?
Cancer promoting genes derived from normal genes (proto-oncogenes).
What are proto-oncogenes and their role?
Normal genes that play an important role in cellular growth and differentiation.
What results from a ‘gain of function’ in proto-oncogenes?
Increased risk of cancer.
How many mutated copies of the gene are needed for cancer to occur in oncogenes?
Only one mutated copy is needed.
What percentage of human cancers are oncogenes implicated in?
Up to 20%.
What processes can turn proto-oncogenes into oncogenes?
Mutation (point mutation), chromosomal translocation, increased protein expression.
Give an example of an oncogene, its category, and associated cancer.
ABL - Cytoplasmic tyrosine kinase - Chronic myeloid leukaemia.
How do tumour suppressor genes differ from oncogenes?
Tumour suppressor genes restrict cellular proliferation, while oncogenes promote it.
What is the role of the p53 gene?
Causes apoptosis of damaged cells.
What happens when tumour suppressor genes lose function?
Increased risk of cancer.
What happens when oncogenes gain function?
Increased risk of cancer.
