Dasatinib effects on tyrosine phosphorylation and downstream signaling in leukemia cells. The effects of treatment with 100 nM dasatinib for 2 hours were compared in the Bcr-Abl positive cell line K562 and the prolymphocytic cell lines JVM-3 and Mec1 (A). The phosphorylation status of the downstream mediators Akt, Erk1/2 and p38 with and without dasatinib treatment was probed in the cell lines JVM-3 and Mec1 and in freshly isolated CLL cells using phosphospecific antibodies and controlled by detection of the expression levels of the respective proteins (B).