Fig. 2

DCZ3301 treatment resulted in apoptosis in BTZ-resistant MM cells. (a) NCI-H929R were treated with DCZ3301 in the indicated concentrations (4 μM, 8 μM, 16 μM) for 48 h, and apoptosis was evaluated with Annexin V/PI staining and flow cytometry. The sum of early apoptotic cells (Annexin V⁺/PI⁻) and late apoptotic cells (Annexin V⁺/PI⁺) form total apoptosis. The percentage of apoptotic cells induced by increasing the concentration of DCZ3301 is shown on the right panel. (b) NCI-H929R treated with 16 μM DCZ3301 for the indicated time (24 h, 48 h, 72 h). Quantification of apoptotic cells is shown in the right panel. (c) DCZ3301 (16 μM) and/or the pan-caspase inhibitor Z-VAD-FMK (50 μM) were added for 48 h, and then we analyzed the percentage of apoptosis. (d) Western blot of the expression of apoptosis-related proteins. (e) Apoptosis in CD138⁺ primary MM cells isolated from three BTZ refractory and relapsed MM patients (Pt) treated with BTZ (40 nM) and DCZ3301 (16 μM) for 48 h. (f) Apoptosis in PBMCs from three healthy donors treated with DCZ3301 for 48 h