The caspase-3 inhibitor zDEVD-fmk does not interfere with CD95- or epirubicin-induced processing of caspase-3 in BJAB cells.

BJAB cells were either incubated in control medium (Co) or stimulated with 1 μg/mL anti-CD95/Fas antibody (F) or 1 μg/mL epirubicin (E). Some cultures were preincubated with 10 μM of the caspase-3 inhibitor zDEVD-fmk (I) 2 hours before anti-CD95 or drug treatment. After 24 hours of incubation, Western blot analyses were performed with antihuman caspase-3 (A, C). The positions of molecular mass markers are indicated at the left. Arrows indicate the positions of procaspase-3 (*) and the 17-kd active subunit of caspase-3 (**). The experiments were repeated and yielded similar results. Additionally, cell death was determined in the cultures after 24 hours of anti-CD95 or epirubicin treatment by trypan blue exclusion (B, D). Values are given as percentage of dead cells ± SD (n = 3).