Cisplatin-induced erythroid differentiation in K562 cells: modulation of transferrin receptor.

The human erythroleukemia cell line K562 can be induced to erythroid terminal differentiation by several chemical agents. The property of inducing cellular differentiation in vitro has also been demonstrated for different antineoplastic agents commonly used in therapeutic protocols. The molecular events involved during erythroid differentiation are wholly unknown. Here we demonstrate that K562 cells, undergoing differentiation by the alkylating agent Cisplatin (cis-diamminedichloro platinum (II), CDDP) employed in clinical protocols for the treatment of solid tumors, are induced to produce haemoglobin. Down modulation of the transferrin receptor (Tfr), highly represented on the cell surface, is also observed during the early stages of differentiation. Furthermore, Tf receptor expression correlates with cell growth, is down regulated and lost during terminal differentiation. The Tfr down regulation is an early event, before haemoglobin production, during cell differentiation. The data suggest that CDDP can induce terminal differentiation in K562 cells in vitro, like other antineoplastic agents.