Fig. 2

Effects of metformin, cisplatin, or a combination thereof on RAD51 protein expression. Western blotting was performed to determine the effects of metformin, cisplatin, or their combination on RAD51 protein expression. β-actin was used as a loading control. Band intensities were quantified and are presented as bar graphs. a Dose-dependent effect of metformin on RAD51 protein expression was determined in Hs 578T (left panel) and MDA-MB-231 (right panel) cells treated with metformin (1~10 mM) for 24 h. b Time course of metformin effects on RAD51 protein expression was determined in Hs 578T (left panel) and MDA-MB-231 (right panel) cells treated with 5 mM metformin for 0, 12, 24, or 36 h. c Dose-dependent effect of cisplatin on RAD51 protein expression in Hs 578T (left panel) and MDA-MB-231 (right panel) cells treated with cisplatin (0.5~10 μM) for 24 h. d Time course of the effect of cisplatin on RAD51 protein expression in Hs 578T (left panel) and MDA-MB-231 (right panel) cells treated with 5 μM cisplatin for 0, 12, 24, or 48 h. e Hs 578T (upper panel) and MDA-MB-231 (lower panel) cells were treated with metformin (5 mM), cisplatin (5 μM), or a combination thereof for 24 h. f MCF10A cells were treated with 5 mM metformin (upper panel) or 5 μM cisplatin (middle panel) for 0, 12, 24, or 48 h. In a separate experiment, MCF10A cells were treated with metformin (5 mM), cisplatin (5 μM), or a combination thereof (lower panel) for 48 h. Results represent the mean ± SEM of five independent experiments. #, ##, ### vs. no treatment; ^#P < 0.05, ^##P < 0.01, ^###P < 0.001, *P < 0.05, **P < 0.01 by one-way ANOVA followed by Bonferroni’s post hoc test. NS: not significant