p53 target genes are up-regulated by MES in HCT116 wild-type (p53+/+) cells.
A–E, HCT116 p53+/+ and HCT116 p53−/− cells were treated with MES (0.1 ms, 1 V/cm, 55 pps) for 30 min, and total RNA was extracted 4 h after treatment. The expression levels of p53 target genes (p21, BAX, NOXA, PUMA, and IRF9) were analyzed by quantitative RT-PCR. GAPDH was used as an internal control. The experiments were performed in triplicate. Error bars indicate the mean ± S.E. *, p < 0.05 versus the control (assessed by Student's t test); **, p < 0.01 versus the control; n.s., not significant. con, control. F, nuclear extracts were obtained from HCT116 p53+/+ cells 3 h after treatment with MES (0.1 ms, 1 V/cm, 55 pps, 30 min) or 12 h after treatment with 5-FU (50 μm). p53 binding to the p21 promoter was assessed by conventional PCR using primers that recognize the p53 consensus site in the p21 promoter. The GAPDH promoter was used as negative control. IP, immunoprecipitate.