Figure 5.

Combination of ZSTK474 and Imatinib led to a synergistic anti-proliferative effect on K562 and K562/A02 cells. (A) Imatinib inhibited the proliferation of K562 and K562/A02 cells. K562 and K562/A02 cells were exposed to indicated concentrations of Imatinib. Cell viability was determined by MTT assay. Data are mean ± SD representative of three independent experiments. (B) Combination with ZSTK474 enhanced the inhibitory activity of Imatinib. K562 and K562/A02 cells were incubated with various concentrations of ZSTK474 and Imatinib (20%, 40%, 60%, 80%, 100% IC₅₀ of each drug), alone or in combination. Cell viability was determined by MTT assay. Data are mean ± SD representative of three independent experiments. (C) Analysis of the combinational effect by using CalcuSyn software. CI-Fa plots are shown for K562 cells (left) and K562/A02 (right). The line of CI=1 is shown. CI: combination index, Fa: Fraction affected.