Fig. 3: BV-6 induces programmed cell death via a RIP(K1)-dependent apoptotic pathway.

A Viability assessment of SF3B1^WT and SF3B1^K700E cells pre-treated for 2 h with DMSO vehicle control, 10 μM necrostatin-1, or 10 μM z-VAD-FMK, followed by a 48 h incubation with 0.1% DMSO vehicle or 1 μM BV-6 (Mean ± SEM; n = 3; 2-way ANOVA with Dunnett’s multiple comparisons). B Caspase-8 activity following 24 h treatment with 0.1% DMSO vehicle or 1 μM BV-6 in SF3B1^WT and SF3B1^K700E cells (Mean ± SEM; n = 3; 2-way ANOVA with Tukey’s multiple comparisons). C Representative Western blot analysis of cFLIP and RIP(K1) protein expression in SF3B1^WT and SF3B1^K700E cells following treatment with the indicated concentrations of BV-6 for 24 h. D Co-immunoprecipitation assay of RIP(K1), pro-caspase-8, cFLIP and FADD following immunoprecipitation of caspase-8 from SF3B1^WT and SF3B1^K700E cells treated with the indicated concentrations of BV-6 for 24 h in the presence of 20 μM z-VAD-FMK. E Activity levels of caspases-3/7 in SF3B1^WT and SF3B1^K700E cells following BV-6 treatment (Mean ± SEM; n = 3; 2-way ANOVA with Tukey’s multiple comparisons). F Proportion of Annexin V⁺ cells following a 48 h incubation with the indicated concentrations of BV-6 in SF3B1^WT and SF3B1^K700E cells (Mean ± SEM; n = 4; 2-way ANOVA with Tukey’s multiple comparisons to compare the total proportions of apoptotic cells, i.e., combined Annexin V⁺/7-AAD⁺ and Annexin V⁺/7-AAD⁻ cells). ^*P < 0.05; ^**P < 0.01; ^***P < 0.001; ^****P < 0.0001.