The second generation tyrosine kinase inhibitor dasatinib induced eryptosis in human erythrocytes-An in vitro study.

Dasatinib, a new tyrosine kinase inhibitor, is used clinically to kill chronic myelogenous leukemia and acute lymphoblastic leukemia through apoptosis. Obviously, anemia is developed in many patients receiving dasatinib for treatment. Until now, the mechanism for the cytotoxic effects of dasatinib in human erythrocytes is not fully understood. As many tyrosine kinases are found in human erythrocytes, it is therefore logical to hypothesize that dasatinib is able to induce apoptosis (or eryptosis) in human erythrocytes. True to our expectation, dasatinib inhibited tyrosine kinase and induced eryptosis in human erythrocytes with early denature of esterase, cell shrinkage, loss of membrane integrity with inside-out phosphatidylserine, increase in the cytosolic Ca ion concentration ([Ca]i), caspase-3 activation and change in cellular redox state. Mechanistically, the rise of [Ca]i seems to be a key mediator in the dasatinib-mediated eryptosis because depletion of external Ca could suppress the eryptotic effects. Also, dasatinib was able to reduce membrane fluidity in human RBCs. For the direct action on membrane, dasatinib permeabilized RBC ghosts in a way similar to digitonin. Taken together, we report here for the first time that dasatinib inhibited tyrosine kinase and induced eryptosis in human erythrocytes through Ca loading and membrane permeabilization.