Fig. 4.

Effect of AIF knockdown on MIE-induced apoptosis in HepG2 and SNU-182 cells. a AIF knockdown by siRNA specific to AIF decreases the nuclear AIF protein expression in MIE-treated cells determined by Western blotting. β-actin served as a loading control. b The relative protein expression levels of AIF normalized by those of β-actin were quantified by Image J. c, d MIE-induced apoptosis is substantially abrogated upon siRNA knockdown of AIF. Apoptotic cells in AIF-silenced and MIE-stimulated HepG2 or SNU-182 cells were analyzed by flow cytometry, and total annexin V-positive cells were quantified. The values are the mean ± SD of three different experiments. *p < 0.05 and **p < 0.005 indicate a significant difference compared with negative siRNA transfectants