Figure 6. Sensitivity of gastric cancer cell lines with stable knockdown of ATM to IR and olaparib. ATM-proficient gastric cancer cell lines STKM2 (p53 wt) and KATOIII (p53 mutant) were transfected with shATM-expressing vector, and were exposed to the indicated concentrations of IR (A and B) or olaparib (C and D). Survival was determined using clonogenic survival assay as described in Figure 3. Each point is in triplicate in 3 independent experiments. Error bars represent SEM.