Effect of the caspase inhibitor z-VAD on the degradation of caspase-3 and caspase-7 in CD437-treated NB4 cells. NB4 cells (300,000/mL) were treated for 6 hours with vehicle (DMSO, Control) and with 10−6 mol/L CD437 following 2 hours preincubation in the absence or in the presence of the indicated concentration of z-VAD. Aliquots of the NB4 homogenates containing an equivalent amount of protein were subjected to Western blot analysis with antibodies specific for caspase-3, caspase-7, and for actin. Solid arrows indicate the position of the band corresponding to pro–caspase-3 and pro–caspase-7, whereas broken arrows indicate the bands corresponding to the large and small subunit of activated caspase-7. The molecular weight of protein standards is indicated on the left. The results were replicated in a separate experiment.
