活性型ビタミンDによる細胞の分化と融合に関する研究

抄録

Recently, much attention has been focused on the ubiquitous distribution of specific 1α,25-(OH)_2-D_3 receptors in normal and cancer cells. This suggests that the role of this vitamin in biology extends far beyond its classical role in mineral metabolism. Since 1981, we have been investigating the differentiating action of vitamin D compounds primarily in hematopoietic cells. 1α,25-(OH)_2-D_3 inhibits proliferation and induces differentiation of immature bone marrow cells and myeloid leukemia cells (M1, HL-60 and U937) preferentially into monocyte-macrophages. Furthermore, the vitamin promotes activation and fusion of mouse alveolar macrophages to form multinucleated giant cells. Of vitamin D_3 derivatives tested, 1α,25-(OH)_2-D_3 is the most potent in inhibiting cell growth and in promoting cell differentiation, activation and fusion. These results suggest the possibilities that 1α,25-(OH)_2-D_3 is involved in multinucleated osteoclast formation in bone and that the in vivo administration of vitamin D compounds to tumor-bearing animals decreases their tumorigenicity.