FIG. 8.

Role of caspases and cytochrome c in the induction of apoptosis by preussin. (A) Effect of caspase inhibition on preussin-induced cell death. HL-60 cells were untreated (−) or treated with preussin (+) after a 1-h preincubation with (+) or without (−) zVAD-fmk (100 μM). The percentage of live (□), apoptotic (■), or necrotic (░⃞) cells is given. Shown are the average results of three independent experiments ± the standard deviation. (B) Immunoblot analysis of procaspases, PARP, and cytoplasmic cytochrome c. Extracts from HL-60 cells that were untreated (Con) or treated with 0.5, 1, or 5 μM preussin for 18 h were analyzed by immunoblotting using antibodies specific for the indicated proteins.