The ETS Family Member Tel Antagonizes the Fli-1 Phenotype in Hematopoietic Cells,

The ETS family member Tel is rearranged in human leukemia of both myeloid and lymphoid origin while the ETS member Fli-1 is insertionally activated in Friend erythroleukemia in mice and is translocated to the EWS locus in Ewingʹs sarcoma. In previous studies we demonstrated that Tel binds to Fli-1 and blocks transactivation of megakaryocytic promoters by Fli-1. In this study we demonstrate that expression of Fli-1 in the leukemia cell line K562 induces a megakaryocytic phenotype and the expression of the platelet markers GPIX, GP1bα, and GPIIb. Introduction of Tel blocked the megakaryocytic phenotype induced by Fli-1, suggesting a biological correlation to the biochemical interaction of Tel and Fli-1 reported previously.