EXEL-0862 leads to mitochondrial damage, cytochrome c release, and activation of caspase-3 and -9. (A) Mitochondrial potential damage was elicited by EXEL-0862. Cells were exposed to EXEL-0862, stained with CMXRos and MTGreen, and immediately analyzed by flow cytometry. Histograms represent the population of cells with damaged mitochondrial potential. Values represent the mean ± SEM values from duplicate experiments. (B) EXEL-0862 treatment induced cytochrome c release into the cytosol. Cells were treated with 0.35 μM EXEL for 24 hours, and the cytosolic fraction was extracted with digitonin buffer. Cytochrome c was detected with immunoblots. (C) EXEL-0862 activated caspase-3 and -9. Cells were exposed to EXEL-0862 at the indicated concentrations for 24 hours. Cell lysates were analyzed by Western blot with antibodies against caspase-9 and caspase-3. (D) Cells were treated with 0.35 μM EXEL-0862 for 24 hours. Expression of apoptosis-related proteins was analyzed by Western blot.