Fig. 1

ATM inhibitor KU55933 sensitizes breast cancer cells to Olaparib a. Western Blot examined the protein level of phospho-ATM (Ser1981), ATM in MCF-7 and CAL-51 cells 48 h after treatment of 10 μM Olaparib, 10 μM KU55933 or their combination, respectively. b, c MTS assay was used to determine cell viability of CAL-51 and MCF-7 cells under different concentration of compounds treatments (0, 1, 2.5, 5, 10 μM Olaparib with or without 10 μM KU55933, respectively) at 37 °C for 48 h. * means that there is statistical difference between the groups of Olaparib treatment with or without KU55933 at each indicating concentration. d, e, Representative pictures (Up) and quantitative analysis (bottom) of colony formation assays. All experiments were performed at least three times and data were statistically analyzed by two-tail t-test.*p < 0.05, ***p < 0.001. Error bars indicate S.E.M