Induction of erythroid differentiation of human K562 cells by cisplatin analogs.

Human leukemic K562 cells can be induced in vitro to erythroid differentiation by a variety of chemical compounds, including hemin, butyric acid, 5-azacytidine, and cytosine arabinoside. Differentiation of K562 cells is associated with an increase in the expression of embryo-fetal globin genes, such as the zeta-, epsilon-, and gamma-globin genes. Therefore, the K562 cell line has been proposed as a very useful in vitro model system for determining the therapeutic potential of new differentiating compounds as well as for studying the molecular mechanism(s) regulating changes in the expression of embryonic and fetal human globin genes. Inducers of erythroid differentiation that stimulate gamma-globin synthesis could be considered for possible use in the experimental therapy of hematological diseases associated with a failure in the expression of adult beta-globin genes. In this paper, we analyzed the effects of a series of cisplatin analogs on both cell growth and differentiation of K562 cells. Among seven cisplatin analogs studied, three were found to be potent inducers of erythroid differentiation. Erythroid differentiation was associated with an increase in the accumulation of (a) hemoglobins Gower 1 and Portland and (b) gamma-globin mRNA.