Western analysis of drug- and radiation-treated cells. The indicated proteins were detected by western analysis of MDA-MB-435S cells treated with the indicated drugs prior to irradiation (IR) (A, B, C). β-actin served as internal control. Relative Rad51 mRNA expression level was measured by quantitative real-time reverse transcription polymerase chain reaction in MDA-MB-435S cells treated with the indicated drugs (D). P < 0.001, **.