Ba/F3p210^Bcr-Abl, Ba/F3p210^E255K, and Ba/F3p210^T315I cells are equally susceptible to OSU-03012 irrespective of Bcr-Abl mutations. (A) Dose-response curves obtained by MTS assays after 48-hour exposure of the control 32D and untransfected Ba/F3 cells versus Ba/F3p210^Bcr-Abl (WT), Ba/F3p210^E255K (E225K), and Ba/F3p210^T315I (T315I) cells to OSU-03012. Each data point represents means ± SD (n = 6). (B) Effect of 5 μM OSU-03012 on cytochrome c release. The immunoblots are representative of 3 independent experiments. (C) Flow cytometric analysis of apoptotic death in the 3 cell lines treated with DMSO vehicle or OSU-03012 at 2.5, 5, 7.5, or 10 μM for 48 hours. Results are representative of at least 3 independent experiments. The percentages in the graphs represent the percent of cell numbers in each quadrant.