Fig. 8.

Role of FLIP and Mcl-1 in ER-induced sensitization to TRAIL. a Cells were treated for 15 h with the indicated concentrations of tunicamycin and protein expression was determined in cell lysates by western blotting with specific antibodies. b MDA-MB231 or HeLa cells were transfected with 50 nM GRP78 siRNA or a control siRNA for 48 h as described in “Materials and methods” section. Cell lysates from transfected cells were analyzed for protein expression. Results are representative of at least three independent experiments. c MDA-MB231 cells were transfected with siRNAs for 48 h and treated with TRAIL (500 ng/ml) for 6 h. Apoptosis was assessed as the percentage of hypodiploid cells. Error bars represent S.D. from three independent experiments. Cell lysates from MDA-MB231 cells transfected with siRNAs (50 nM) for 48 h were analyzed for protein expression as described in “Materials and methods” section. d Mock-transfected and MDA-MB231 cells transfected with the pCR3.V64-Met-Flag-FLIP_L vector were treated with or without tunicamycin (250 ng/ml) for 15 h prior to the incubation with or without TRAIL (500 ng/ml) for 6 h. Protein expression was determined by western blotting (left panel). Apoptosis was measured as the percentage of cells with sub-G1 DNA content (right panel). Error bars represent S.D. from three independent experiments. ***P <0.001. e Mock or FLIP_L-overexpressing MDA-MB231 cells were transfected with siRNAs (50 nM) for 48 h and then treated with TRAIL for 24 h. Apoptosis was assessed as the percentage of cells with sub-G1 DNA content. Error bars represent S.D. from three independent experiments. *P <0.05