Platelet factor 4 mRNA expression in human erythroleukemic cells: regulation by phorbol esters and certain cytokines.

Developing megakaryocytes are distinguished from progenitor cells by the appearance of platelet proteins such as platelet factor 4 (PF 4). The human erythroleukemic cell line HEL can also be induced to produce PF 4 by incubation in phorbol esters. HEL cells were used here as a model system in which to study the phenomenon of inducible PF 4 production at both the mRNA and protein levels. The cytokines interleukin 1 beta (IL-1 beta), interleukin 3 (IL-3), interleukin 6 (IL-6), granulocyte-macrophage colony-stimulating factor (GM-CSF), erythropoietin (EPO), and transforming growth factor-beta (TGF-beta) were also evaluated for their effects on PF 4 mRNA induction in HEL cells.