Bcl-xL and Myeloid cell leukaemia-1 contribute to apoptosis resistance of colorectal cancer cells

Figure 6 TRAIL- and CD95-induced apoptosis after modulation of Mcl-1 and Bcl-x_L expression. A: SW480 or SW620 cells were transfected with siRNA specific for Bcl-x_L or GFP as control. 24 h post transfection cells were treated with TRAIL (0.1 &mgr;g/mL) for further 24 h. Cells were then harvested and analyzed for apoptosis induction by flow cytometry; B: SW480 cells were transfected with siRNA specific for Mcl-1 or GFP as control. 24 h post transfection cells were treated with TRAIL (0.01 &mgr;g/mL) for further 24 h. Cells were then harvested and analyzed for apoptosis induction by flow cytometry; C: SW480 cells were transfected with pcDNA3 Bcl-x_L or pcDNA3 empty vector as control. 24 h post transfection, cells were treated with TRAIL (0.1 &mgr;g/mL) for further 12 h. Cells were then harvested and analyzed for apoptosis induction by flow cytometry; D: SW480 cells were transfected with siRNA specific for Mcl-1 (left panel) or Bcl-x_L (right panel) or with control siRNA. 24 h post transfection cells were treated with anti-APO-1 (0.1 &mgr;g/mL) for further 24 h. Cells were then harvested and analyzed for apoptosis induction by flow cytometry. All assays were performed in triplicates and are representative for at least three independent experiments. Values are mean ± SD, ^aP < 0.05.