Figure 5. The impact of cisplatin on the induction of apoptosis in PC9 cells. (A) Apoptosis was assessed by Annexin V/PI dual staining. Flow cytometry was used to evaluate the number of Annexin V- and PI-positive cells. Quadrant 1 shows necrotic cells, quadrant 2 late-apoptotic cells, quadrant 3 early-apoptotic cells and quadrant 4 viable cells. (B) A bar diagram illustrates the percentage of apoptotic cells. The values were calculated as the mean±SD from three independent experiments. Significance was determined by one-way ANOVA with Bonferroni’s multiple comparison test: *p<0.05, **p<0.01 and ***p<0.001 compared with the DMSO-treated group. (C) To assess the expression of Fas, FasL, Bak, caspase-9, caspase-8, Bax, BID, cleaved caspase-7 (Asp 198), cleaved caspase-3 (Asp 175), cleaved caspase-6 (Asp 162), and PARP proteins, Western blotting was performed. β-actin served as a loading control. Representative immunoblots from three independent experiments are shown.