Cyclosporin A induces erythroid differentiation of K562 cells through p38 MAPK and ERK pathways

Abstract
We studied the effects of cyclosporin A (CsA) on the erythroid differentiation of human erythroid leukemia cell line K562. After K562 was treated with CsA for 4 days, the percentage of hemoglobinized cells was increased by 3.3 times. Because it was reported p38 MAPK (p38) and ERK are involved in erythropoietin‐induced erythroid differentiation, we studied their roles using specific inhibitors. p38 inhibitor (SB203580) prevented CsA‐induced hemoglobin synthesis in K562 cells, although MEK/ERK inhibitor (U0126) enhanced it by 3.3 times in K562 cells. These results indicate activation of p38 and inactivation of ERK are involved in CsA‐induced erythroid differentiation of K562 cells. Am. J. Hematol. 72:67–69, 2003.