Megakaryocytic Differentiation Induced in 416B Myeloid Cells by GATA-2 and GATA-3 Transgenes or 5-Azacytidine

The GATA ‘zinc-finger’ transcription factors are thought to have important roles in the control of hematopoiesis. GATA-1 and GATA-2 are found in the erythroid, mast cell, and megakaryocytic lineages, and GATA-3 in T lymphocytes. GATA-1 is required for erythroid development and has recently been shown by gene transfer to direct megakaryocytic differentiation of the primitive myeloid cell line 41 6B. Here we show that enforced expression in 41 6B cells of either the GATA-2 or GATA-3 gene also induces megakaryocytic differentiation, as assessed by cellular morphology, acetylcholinesterase activity, polyploid DNA content, and loss of Mac-1 expression. No erythroid or mast cell differentiation was found. Unexpectedly, the level of endogenous GATA-1 mRNA had increased 20to 30-fold among the transfectants, whereas that of GATA-2