Induction of apoptosis in LAMA 84 cells by SAHA or SB and bortezomib. (A) LAMA 84 cells were exposed to 4.5 nM bortezomib ± 1.5 μM SAHA for 48 hours, after which the percentage of annexin V/PI⁺ cells (shown above gated area) was determined by flow cytometry as described in “Materials and methods.” An additional 2 studies yielded equivalent results. (B) Cotreatment of LAMA 84 cells with 3.5 nM bortezomib and 1.5 μM SAHA or 1.5 mM sodium butyrate (SB) for 48 hours, after which the percentage of apoptotic cells was assessed as described in “Materials and methods.” (C) K562 cells were exposed to 2.0 μM SAHA ± 200 nM MG132 for 48 hours, after which the percentage of apoptotic cells was assessed as described in “Materials and methods.” In each case, values represent the means ± SD for 3 separate experiments.