Fig. 5

Blockade of FADD significantly reduces TL/Btz-induced apoptosis. a U266 and PS-R cells were treated with Btz +/− TL for 24 h. Immunoblotting analysis was carried out to monitor caspase-8 expression. CF cleavage fragment. β-actin was assayed to ensure equivalent loading and transfer. b–c U266/DN-FADD and U266/EV cells were established by stably transfecting human dominant-negative FADD cDNA or empty vector. Cells were treated with Btz +/− TL for 24 h. c After drug treatment, cells were subjected to flow cytometry to determine the percentage of dead (7-AAD⁺) cells (**P < 0.01). Values represent the means ± SD for at least three independent experiments performed in triplicate. Immunoblotting analysis was performed to monitor FADD, caspase-8, and PARP expression. Endo, endogenous; CF. cleavage fragment. GAPDH was assayed to ensure equivalent loading and transfer