Induction of insulin receptor expression of human leukemic cells by 1 alpha, 25 dihydroxyvitamin D3

The HL-60 and U-937 leukemic cell line and explants of fresh human leukemia cells were differentiated in vitro by incubation with 1 alpha, 25 dihydroxyvitamin D3 (Vit D). Morphologic change to monocytes was demonstrated in the promyelocytic (HL-60) line but not in the U-937 line and four of five leukemic cells. One patient with chronic granulocytic leukemia in the myeloid blast phase had incomplete morphologic change with Vit D treatment. In all cells studied, an increase in specific insulin receptor binding was independent of morphologic maturation. An increase in insulin receptor expression by Vit D was an early monocytic membrane marker dissociated from morphologic and functional alterations.