The BH3-only proteins Noxa and Bim are essential for MP-A08–induced cell death. (A) Mcl-1 immunoprecipitation of MV411 cells treated with MP-A08 for 6 hours and subjected to immunoblot analysis with the indicated antibodies. (B) Quantitative polymerase chain reaction analysis of MV411 cells treated with MP-A08 (20 μM) over 6 hours. (C) Immunoblot analysis of MV411 cells treated with MP-A08 in the presence of cycloheximide for 6 hours. MV411 (D) or OCI-AML3 (E) were treated with increasing concentrations of MP-A08 for 6 hours and subjected to immunoblot analysis with the indicated antibodies. MV411 cells were lentivirally transduced with shRNAs targeting Noxa (F), Bim (G), or Bid (H) and treated with doxycycline for 48 hours and MP-A08 (15 μM) for either 6 hours for immunoblot analysis or 24 hours for cell viability using Annexin V staining. All qualitative data are representative of at least 3 independent experiments, and all quantitative data are the mean ± standard error of the mean from 3 independent experiments. Statistical significance was assessed by Student t test. *P < .05; **P < .005; ***P < .0001. N.S., not significant.