Fig. 1: Induction of mitochondrial outer membrane permeabilization (MOMP) when permeabilized cells are directly treated with BH3 mimetic compounds.
A Efficacy of various BH3 mimetic compounds at causing MOMP when added directly to permeabilized CLL cells. Freshly isolated primary CLL samples (n = 6) were permeabilized and then treated with 0–10 µM of the indicated BH3 mimetic (binding specificity summarized in Fig. S1A) to selectively target BCL2, MCL1 or BCLXL, or with ABT-737 which targets BCL2, BCLXL and BCLW, and mitochondrial depolarization determined 1.5 h later. Data represents mean IC50 ± SD of the 6 samples; experiment performed once per sample. B Sensitivity of CLL cells to BH3 mimetics. Intact CLL cells, identical to those permeabilized in (A), were treated for 1.5–24 h with 0–10 µM of the indicated BH3 mimetic. Viable cells (PI-ve/Annexin V-ve) were identified by flow cytometric analysis and the resulting IC50 calculated. Each data point represents a patient sample studied once; 6 patient samples were studied. C Similar BH3 profiling assays to those in (A) were undertaken with permeabilized KMS-12-PE cells, a multiple myeloma cell line. (D) As in (B), cell viability assays were undertaken with intact KMS-12-PE cells treated with the indicated BH3 mimetic (the dose responses are shown in Figs. S1B-C). Identical sets of experiments were undertaken with (E) permeabilized AMO1 myeloma cells or (F) intact cells (dose responses shown in Figs. S1H-I). G At high doses, venetoclax or other BH3 mimetics could cause non-specific mitochondrial damage. Mitochondrial assays were undertaken after treating permeabilized BAX–/–BAK–/– KMS-12-PE cells with the indicated BH3 mimetic for 1.5 h. H Similar assays to those in (G) were undertaken with permeabilized BAX/BAK-deficient AMO1 cells. The data in (C)–(H) represents the means ± SD of ≥3 independent experiments; IC50 indicated in parentheses. See also Fig. S1.
