The mechanism of Bay 11-7082-induced MM cell death involves necrosis.

<p>(A) MM.1S and KMS-12-BM cells were treated with 30 µM Bay 11-7082 and analyzed by time-lapse video microscopy. Pictures shown represent typical stages of cells undergoing Bay 11-7082-induced cell death within 3 h. (B) Cells were pretreated for 30 min with BHA (50 µM), necrostatin-1 (90 µM) or remained untreated and were then challenged with 30 µM Bay 11-7082 for 2 h. Cells were finally photographed (B, arrows indicate swollen cells and the plasma membrane). (C) MM cells were either left untreated or pretreated for 1 h with BHA (50 µM), necrostatin-1 (90 µM), z-VAD-fmk (100 µM) or both necrostatin-1 and z-VAD-fmk. Cells were then challenged with 15 µM Bay 11-7082 for 1 h (KMS-12-BM) or 2 h (MM.1S) followed by annexin V-FITC/PI staining and FACS analysis. (D) MM.1S and KMS-12-BM cells were pretreated in triplicates for 30 min with the indicated combinations of BHA (50 µM), necrostatin-1 (90 µM) and z-VAD-fmk (100 µM), exposed for 2 h to 30 µM Bay 11-7082 and then analyzed for viability using the MTT assay. For statistical analysis a one-way ANOVA with a Tukey post-test was performed. Experimental settings that display significant protection against Bay 11-7082 induced cell death (p-values≤0.01) are indicated by asterisks.