1α,25-Dihydroxycholecalciferol Increases the Expression of Vascular Endothelial Growth Factor in C3H10T½ Mouse Embryo Fibroblasts

Abstract

Evidence suggests that biologically active vitamin D, 1,25-dihydroxycholecalciferol [1,25(OH)(2)D(3)], may inhibit carcinogenesis. Because angiogenesis is crucial to carcinogenesis, 1,25(OH)(2)D(3) regulation of proangiogenic vascular endothelial growth factor (VEGF) secretion was investigated in cellular models for multistage carcinogenesis. Conditioned media from 1,25(OH)(2)D(3)-treated C3H10T(1/2) mouse fibroblasts and their Harvey ras-oncogene transfected counterparts (rasneo11a cells) induced human umbilical vein endothelial cell (HUVEC) proliferation (1.3 and 0.3 times, respectively, P < 0.05), suggesting that 1,25(OH)(2)D(3) altered the angiogenic phenotype of the cells. Although rasneo11a cells secreted less VEGF than C3H10T(1/2) cells (97%, P < 0.005), 1,25(OH)(2)D(3) induced C3H10T(1/2) and rasneo11a cells to secrete 2 and 3 times, respectively, more VEGF than controls (P < 0.05). Similar effects on VEGF release occurred after 1,25(OH)(2)D(3) treatment of MCF10A and MCF10Aras cells, a human breast epithelial cell model for multistage carcinogenesis. In C3H10T(1/2) cells, 1,25(OH)(2)D(3) activated the VEGF promoter in a dose-dependent (5-100 nmol/L) manner (maximum 60%) and all doses induced VEGF secretion (P < 0.05). 1,25(OH)(2)D(3) induced VEGF mRNA expression ( approximately 50%) from 2 through 24 h; VEGF release was significantly increased at 8 h and sustained for 24 h. VEGF mRNA expression and release declined as C3H10T(1/2) cells grew more confluent, whereas the magnitude of 1,25(OH)(2)D(3)-stimulated changes in VEGF was greater in confluent (3.3 times RNA; 3.5 times release) than in subconfluent (50% RNA; 100% release) cultures (P < 0.05). Thus, 1,25(OH)(2)D(3) increases VEGF secretion, and in C3H10T(1/2) cells, this is likely through activation of the VEGF promoter and induction of gene expression. These data contribute to understanding the role 1,25(OH)(2)D(3) plays in regulation of angiogenesis in normal compared with disease states.