TP53 and gastric cancer: In our study, 5-aza-dC increased the level of apoptosis in HCT116 and SW480 cells, a finding that was consistent with results from Qiu et al. Very interestingly, Qiu et al. also suggested that gastric cancer cell lines expressing wild-type p53 are more sensitive to combination therapy with IR and 5-aza-dC compared with those expressing mutant p53.