Fig. 4.

BCR-ABL^T315I inhibitory activity of ON012380. (A) BCR-ABL kinase assays were performed with T315I recombinant protein as described for Fig. 1 by using c-Crk as a substrate. The values from individual samples were analyzed and plotted as a function of inhibitor concentration. (B and C) Imatinib-resistant 32D/BCR-ABL^T315I cells were treated with various concentrations of imatinib or ON012380, and the BCR-ABL immunoprecipitates were subjected to in vitro kinase assays. BCR-ABL autophosphorylation (B) and substrate phosphorylation (Crk) (C) are shown. (D) Total cell lysates derived from 32D/BCR-ABL^T315I cells treated with DMSO (control), imatinib, or ON012380 were examined by Western blot analysis for the expression of phosphorylated STAT-5.