Fig. 4. Effect of uranyl nitrate on the expression of DNA repair proteins. (A) Effect of different concentrations of uranyl nitrate on HR pathway proteins in BEP2D cells, detected by western blot analysis. (B)–(F) The densitometric quantitation of the expression of proteins by western blot analyses for ATM (B), BRCA1 (C), EXO1 (D), RAP80 (E) and RAD51 (F). (G) Effect of different concentrations of uranyl nitrate on NHEJ pathway proteins in BEP2D cells, detected by western blot analysis. (H) The densitometric quantitation of the expression of proteins by western blot analyses for 53BP1. (I) The densitometric quantitation of the expression of proteins by western blot analyses for DNA-PK complex. The intensities of western blot hybridization bands were quantified using the Quantity One software. β-Actin was used as the sample loading control. *P < 0.05, **p < 0.01.