The dark side of a tumor suppressor:: anti-apoptotic p53

Depending on multiple factors DNA damage leads either to cell cycle arrest or apoptosis. One of the main players deciding the fate of a cell is the tumor suppressor p53 that modulates these responses in a transcription-dependent and -independent manner. Over the past few years, however, strong evidence accumulated that p53 engages also powerful pro-survival pathways by transcriptionally activating a multitude of genes whose products efficiently counteract apoptosis. Our review summarizes the current knowledge concerning approximately forty p53-regulated proteins that exert their anti-apoptotic potential by interfering with diverse cellular processes. These activities are surely essential for normal development and maintenance of a healthy organism, but may easily turn into the dark side of the tumor suppressor p53 contributing to tumorigenesis.