Thiazolidinedione suppresses the expression of erythroid phenotype in erythroleukemia cell line K562

The activation of PPAR gamma:RXR nuclear system induces monocytic different iation of some myelogeneous leukemia cell lines. The present study was unde rtaken to examine the effect of PPAR gamma ligand, TZD (troglitazone or pio glitazone) and/or RXR selective ligand, LG100268 on the erythroleukaemia ce ll line K562 which has both an erythroid character and a potential for diff erentiation into megakaryocytes. TZD suppressed cell proliferation and the erythroid phenotype of K562 cells. The suppression of erythroid phenotype o f K562 cells by TZD was synergistically enhanced by the combined treatment with LG100268. Moreover, the marked suppression of erythroid phenotype in K 562 cells was also accompanied by the downregulation of the erythroid linea ge-transcription factor, GATA-1. These novel actions of troglitazone may pr ovide a biochemical basis for anemia occasionally which is observed after t he in vivo administration of TZD. (C) 2000 Elsevier Science Ltd. All rights reserved.