Demonstration of caspase-8 activation in TRAIL-resistant myeloma cells preincubated with CHX, BIM, or SN50 before TRAIL treatment.

(A) Caspase-8 activity was determined by use of the ApoAlert caspase-8 colorimetric kit in highly TRAIL-resistant IM-9 cells that were incubated with CHX (0.1 μg/mL), BIM (20 μM), or SN50 (30 μg/mL) for 6 hours before treatment with TRAIL (300 ng/mL) for 30 minutes. (B) Immunoblot analysis for caspase-8 cleavage in IM-9 cells preincubated with BIM (20 μM) or SN50 (30 μg/mL) for 6 hours before treatment with TRAIL (300 ng/mL) for 1 hour.