EB-1089, A NOVEL VITAMIN-D ANALOG, HAS STRONG ANTIPROLIFERATIVE AND DIFFERENTIATION-INDUCING EFFECTS ON CANCER-CELLS

EB 1089 is a novel vitamin D analogue which in vitro strongly inhibits the proliferation of U937 histiocytic lymphoma cells and MCF-7 breast cancer cells, with a potency of 50 to 100 times that of 1,25-dihydrox yvitamin D3 [1,25(OH)2D3]. Studies of c-myc and c-fos expression in MC F-7 cells and of differentiation markers in U937 cells show that growt h inhibition by EB 1089 is accompanied by induction of differentiation . The ability of EB 1089 to affect calcium metabolism in vivo in rats is decreased, compared to 1,25(OH)2D3. This low calcemic effect combin ed with the strong biological effect on cancer cells in vitro, makes E B 1089 an interesting candidate for treatment of cancer.