Fig. 5.
Apoptosis regulated by BCL-XL requires BH3-only proteins. a Apoptosis was assessed by PS externalization in the indicated cell lines following exposure to A-1331852 (100 nM) and/or S63845 (100 nM) for the indicated times. HCT116 WT and 8KO cells were exposed to S63845 or A-1331852 (100 nM) for 24 h and assessed for b PS externalization, c cytochrome c release and d BAX translocation. For (c) and (d), cells were pre-treated with z-VAD.FMK (30 μM) for 0.5 h before exposure to BH3 mimetics. HCT116 WT and 8KO cells were e transfected with siRNA against BCL-XL and/or MCL-1 for 72 h and assessed for PS externalization or f exposed to A-1331852 (100 nM) and/or S63845 (100 nM) and the number of colonies formed after 7 d was counted and images taken using GelCount. Representative images from the clonogenic assay are shown in the right panel. Error bars = Mean ± SEM (standard error of the mean); *p ≤ 0.05; **p ≤ 0.01; ***p ≤ 0.001