We aimed to evaluate the cytotoxic and apoptotic effects of dasatinib (BMS-354825) on K562 chronic myeloid leukemia (CML) cells and to examine the roles of STAT genes on dasatinib-induced apoptosis. The results showed that dasatinib decreased proliferation and induced apoptosis in K562 cells in a dose- and time-dependent manner. mRNA and protein levels of STAT5A and STAT5B genes were significantly reduced in dasatinib-treated K562 cells. These data indicated that STAT inhibition by dasatinib might be therapeutic in JAK/STAT pathway associated malignancies after confirmation with clinical studies. (C) 2015 Elsevier Inc. All rights reserved.