Synergistic effects of HI and imatinib on BA/F3p210 cells. (A-B) MTT assay. Isobolograms for the effects of imatinib and CPX (A) or GC7 (B), respectively, on cellular proliferation after 48 hours. (C-F) Apoptosis. Co-treatment with imatinib and CPX (C) or GC7 (D) increased apoptosis in BA/F3p210 cells. No synergistic effects in apoptosis induction were observed in wt-BA/F3 cells for the combination of imatinib with CPX (E) or GC7 (F). Apoptotic cell fractions were measured by PI staining. Values (mean ± SD of 3 experiments) are depicted as bar graphs.