FIG. 1.

VT-1 and staurosporine induce caspase-dependent apoptotic cell death in some, but not all, BL cell lines. (A) Cells were incubated for 16 h with VT-1 (5 ng/ml), staurosporine (2.5 μM), or complete RPMI medium (control). The cells were labeled with annexin V-FITC and PI and analyzed with a FACSCalibur flow cytometer to determine the percentages of apoptotic cells. Error bars show the standard deviations. (B) Cells were incubated for 16 h with VT-1, staurosporine, or complete RPMI medium (−). Cell pellets were lysed and equal amounts of protein were subjected to electrophoresis in 12% bis-Tris precast gels. The proteins were transferred to PVDF membranes, which were probed with an anti-caspase 8 MAb or an anti-PARP MAb. Molecular sizes are indicated to the right of each gel.