Cytotoxic effect of bortezomib and POH on MCL cell lines. (A) Assessment of viability by staining non-fixed Rec-1 cells with PI (30 μg/mL) followed by flow cytometric analysis showing populations of (a) live cells, (b) necrotic cells, and (c) apoptotic cells. (B) Viability of Rec-1 and Jeko-1 cells treated with either 20 nM bortezomib or 0.3 mM POH for 24 hours relative to controls exposed only to vehicle shown as mean ± 1SD from triplicate wells. The unpaired t-test between viability of Jeko-1 and Rec-1 cells treated with bortezomib * p = 0.002 or POH **p = 0.0001 were both statistically significant (p < 0.01). (C) EMSAs of whole cell extracts from 1.0 × 106 cells treated with 20 nM bortezomib or their respective median-effect dose of POH for 4 hours probed with 32P-radiolabeled oligonucleotide containing either the consensus NF-κB or Oct-1 binding sequence. Fold activity refers to NF-κB binding normalized to Oct-1 binding in each condition.