A large number of studies suggests that double-strand breaks (DSBs) induced in DNA by ionizing radiation or chemical agents are critical lesions, which if unrepaired or misrepaired may kill a cell, or cause its transformation to a cancer cell. Cells have developed efficient repair mechanisms to remove DSBs and restore integrity to their DNA. Despite the potential importance of DSBs in cell killing and transformation, relatively little is known regarding DSB repair mechanisms and the enzymes involved. However, characterization of these processes is crucial for a complete understanding of the consequences of exposure to agents, inducing DSBs.
