Fig. 2From: PARP inhibitors in gastric cancer: beacon of hopeThe principle of synthetic lethality. PARP is involved in SSB repair, and when PARP inhibitors can bind competitively with PARP, it leads to a large accumulation of SSB in the cell that cannot be repaired in time. Unrepaired SSB will lead to the collapse of replication fork, resulting in DSB. In normal cells, DSB can be repaired. In HRD tumor cells, DSB can not be repaired, resulting in a significant increase in the probability of tumor cell death. According to the synthetic lethal principle, PARP inhibitors can selectively kill tumor cells without affecting normal somatic cellsBack to article page