Fig. 2.

Effects of CPA on TRAIL-induced apoptosis are dependent on the activation of caspase-8. DU145 cells were pretreated without or with 50 μM CPA for 24 h, and then treated without or with 50 ng/ml TRAIL for 6 h. When needed, 10 μM Z-IETD-FMK was pre-added to cells 1 h before TRAIL treatment. Cells were harvested and subjected to western blot analysis. a Representative western blot images of PARP, caspase-8 p18, Bid and β-actin were shown. The western blot results were quantitated and normalized to β-actin. The caspase-8 p18 b and Bid c protein levels relative to those of control cells and the percentage of cleaved PARP d are shown. Data shown are means ± S.E. (n = 3) with **p < 0.01