Effect of sodium arsenite on cleaved caspase-8, −9 and −3 and PARP protein expression in MA-10 cells. MA-10 cells were treated without or with sodium arsenite (0.01–100 µM) for 3, 6, 12 and 24 h. Cleaved caspase-8, −9 and −3, and PARP protein expressions were detected by western blotting. (A) Data is representative of one experiment that was further repeated three times. The integrated optical densities of (B) cleaved caspase-8, (C) −9 and (D) −3 and (E) PARP protein expressions were analyzed after normalization to β-actin (43 kDa). Data in B, C, D and E represent the means ± standard error of the mean of three separate experiments. *P<0.05. PARP, poly(ADP-ribose) polymerase.