Effects of PF-228 on Gem-induced apoptosis in Panc-1 cells. Panc-1 cells were pretreated with or without PF-228 (1 μM) for 1 h and then treated with or without 10 μM Gem for 72 h in the continued presence or absence of PF-228. The cells were subjected to apoptosis analysis by Hoechst staining (the arrow indicates the apoptotic cells) (A), flow cytometry analysis of Annexin-V labeling (B) and western blot analysis of cleaved caspase-3 protein expression (C). Bars represent the mean of three independent experiments ± SE. *, P < 0.05, vs. Panc-1 cells without Gem treatment; #, P < 0.05, vs. Gem-treated Panc-1 cells without PF-228 pretreatment.