Fig. 2.

JL5 enhances TRAIL activation of caspase-3. a-b Immunoblot analysis of activated caspase-8 in (a) H1299 and (b) A549 cells treated with JL5 and TRAIL alone and in combination for 3 and 24 h. Trail induced cleavage of procaspase-8 into 41 kDa and 43 kDa activated fragments in H1299 cells but not in A549 cells. (C) Western blot analysis in H1299 demonstrated that caspase-3 is fully processed to its active 17 kDa fragment at 24 h only in cells treated with both JL5 and TRAIL. c The caspase inhibitor Z-VAD-FMK (VAD) prevented JL5/TRAIL processing of caspase-3 into its 17 and 19 kDa fragments. d TRAIL and/or JL5 did not activate caspase-3 in A549 cells. e Western blot analysis demonstrated PARP cleavage into the 85 kDa fragment only in H1299 cells treated with both JL5 and TRAIL for 24 h. f VAD inhibited cell death induced by JL5 in combination with TRAIL in H1299 cells. Data represents the mean percentage of dead cells of 4 independent experiments