Specific effects of somatic GATA2 zinc finger mutations on erythroid differentiation.

ABSTRACT

GATA2 zinc-finger (ZF) mutations are associated with distinct entities of myeloid malignancies. The specific distribution of these mutations points toward different mechanisms of leukemogenesis depending on the ZF domain affected. In this study, we compared recurring somatic mutations in ZF1 and ZF2. All tested ZF mutants disrupted DNA binding in vitro. In transcription assays, co-expression of FOG1 counteracted GATA2-dependent transcriptional activation, while a variable response to FOG1-mediated repression was observed for individual GATA2 mutants. In primary murine bone marrow cells, GATA2 wild-type (WT) expression inhibited colony formation, while this effect was reduced for both mutants A318T (ZF1) and L359V (ZF2) with a shift toward granulopoiesis. In primary human CD34+ bone marrow cells and in the myeloid cell line K562, ectopic expression of GATA2 L359V, but not A318T or G320D, caused a block of erythroid differentiation accompanied by downregulation of GATA1, STAT5B, and PLCG1. Our findings may explain the role of GATA2 L359V during the progression of chronic myeloid leukemia and the collaboration of GATA2 ZF1 alterations with CEBPA double mutations in erythroleukemia.