Regulation by calcium of the synthesis of 1,25-dihydroxyvitamin D3 and 24,25-dihydroxyvitamin D3 in Walker 256 carcinosarcoma cells: comparison with synthesis regulation from renal phenotype cells (LLC-PK1)

The aim of this work was to study the regulation by calcium of the synthesis of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) and 24,25-dihydroxyvitamin D3 (24,25(OH)2D3) in Walker 256 carcinosarcoma (W256) cells compared to renal phenotype LLC-PK1 cells. We have detected synthesis of 1,25(OH)2D3 and 24,25(OH)2D3 in W256 cells. Levels of 1,25(OH)2D3 in W256 were similar to those of LLC-PK1 cells. Levels of 24,25(OH)2D3 were higher in W256 than in LLC-PK1 cells. High levels of calcium inhibited 1,25(OH)2D3 synthesis in LLC-PK1 cells but not in W256 cells.