Bay 61–3606 sensitizes MCF-7 cells to TRAIL by decreasing Mcl-1.

(A, B) After MCF-7 cells were exposed to TRAIL (50 ng/ml) with or without Bay 61–3606 (2.5 μM) for 12 h, cells were extracted and analyzed by immunoblotting analysis using the indicated antibodies. (C) MCF-7 cells were exposed to several concentrations of Bay 61–3606 (upper) for 6 h or to 2.5 μM Bay 61–3606 for the indicated times (lower), and expression of Mcl-1 was analyzed by Western blotting. (D) MCF-7 cells were transfected with scrambled (siCTL) or Mcl-1 siRNA (siMcl-1). After 48 h, cells were exposed to TRAIL (50 ng/ml) for 24 h. The percentage of cell death was evaluated by trypan blue exclusion. Values are the mean ± SE from three separate experiments performed in triplicate. Asterisks indicate significant differences compared with the control (** P-values < 0.01).