BMS-345541 induction of apoptosis in C8166. A) BMS-345541 induced caspase-3 and PARP cleavage C8166. MT-2, C8166, and CEM cells were treated with BMS-345541 at 0.1, 0.5, 1, and 5 μM for 48 hr. Total cell extracts were subjected to Western blot analysis for caspase-3 and PARP. β-actin Western blot was used as internal control. The results of caspase-3 were quantitated and normalized with β-actin. The ratio of c/un PARP was calculated by dividing cleaved PARP to un-cleaved PARP (data not shown). B) Detection of apoptosis through annexin V and PI staining. Cells were washed three times in PBS and re-suspended in binding buffer, stained with annexin V-FITC and PI for 15 minutes at room temperature. Analysis was performed on a BD FacsCalibur flow cytometer.