Fig. 3: BAPTAi-induced cell death is dependent on decreased abundance of MCL-1 proteins and is prevented by reinforcing MCL-1-protein levels.
A Concentration-response curve of the MCL-1 inhibitor S63845 on cell survival in OCI-LY-1, SU-DHL-4, H929, OCI-AML-2, OCI-AML-3 and WEHI-231 cells (left to right) after 6 h of treatment. Cell death was measured using annexin V-FITC and 7-AAD staining, and the apoptotic fraction was identified as annexin V-positive cells. (N = 3). B WT (parental control) and MCL-1-dependent SVEC cell lines were treated for 6 h with vehicle (dark blue), 10 µM TF-BAPTA-AM (yellow), BAPTA-AM (red), MCL-1 inhibitor S63845 (purple), 1 µM BCL-XL inhibitor A1155483 (pink) or 10 µM BCL-2 inhibitor venetoclax (burgundy). Cells were stained with annexin V-APC and 7-AAD, and cell death was measured via flow cytometry. Data are represented as the average ± S.D. (N = 4). Statistically significant differences were determined with a paired ANOVA test. Differences were considered statistically significant when p < 0.05 (**p < 0.01; ***p < 0.001, ****p < 0.0001). C OCI-LY-1 cells were transfected with an empty vector (EV), a BCL-XL-overexpressing plasmid, a wild-type (WT) MCL-1-overexpressing plasmid or a plasmid overexpressing a nondegradable KR mutant of MCL-1. Statistical analysis of cell death in transfected OCI-LY-1 cells after 6 h of 10 µM TF-BAPTA-AM or BAPTA-AM treatment normalized to vehicle. Cells were stained with annexin V-APC and 7-AAD, and apoptosis was measured via flow cytometry. Data are represented as the average ± S.D. (N = 5). Statistically significant differences were determined with a paired ANOVA test. Differences were considered significant when p < 0.05 (**p < 0.01; ***p < 0.001, ****p < 0.0001).
