The ART-induced radiosensitivity in HeLa (A) and SiHa (B) cells. (C) and (D) The ART-induced radiosensitivity in wild-type p53-overexpression HeLa and SiHa cells. Western blot of p53 and internal control in pcDNA3.1- or pcDNA3.1-p53-transfected HeLa (C) and SiHa (D) cells. Clonogenic cell survival curves were generated for HeLa and SiHa cells that were treated with the indicated concentrations of ART for 24 h and then were exposed to 2, 4, 6 or 8 Gy IR. The survival data were normalized to those of the unirradiated control group. The data are shown as mean ± SEM for three independent experiments. The SER was calculated for HeLa or SiHa cells that were treated with 2.0 or 2.5 μmol/L ART prior to X-ray irradiation according to the multi-target single hit model. Values shown are the mean ± SEM for three independent experiments. *P < 0.05; **P < 0.01, compared with irradiated cells.