Induction of apoptosis by tumor suppressor genes and oncogenes

The p53 tumor suppressor gene product, and thebcr-abl,bcl-2, and c-mycgene products all appear to influence the susceptibility of cells to apoptosis. In addition to the role p53 protein plays in mediating a cell cycle arrest in G1 following DNA damage, p53 also performs functions critical for removal of damaged cells by initiating apoptosis in certain physiological situations. Cells which express deregulated c-mycare sensitized to apoptosis following various growth suppressing stimuli and these observations have provided new insights into how apoptosis-suppressing genes such as mutant p53,bcl-2 andbcr-ablmay cooperate during transformation and how they might influence the sensitivity of cells to radiation and chemotherapy.