The Effect Of 1, 25(OH)₂D₃ And 5-fluoRouracil On Growth And Apoptosis In Human Breast Cancer Cells

Objective To study the effect of 1,25(OH)2D3 and 5-fluorouracil on growth and apoptosis in human breast cancer cells. Methods MCF-7 human breast carcinoma cell lines were treated with 1,25(OH)2D3 or 5-fluorouracil alone, or in combination in vitro. Cell proliferation was evaluated by MTT assay, distribution of cell cycle and rate of apoptosis were determined by flow cyto-metry, and detected expression of bcl-2 protein by immuno-histochemistry.Results The inhibitory effect of 1,25(OH)2D3 and 5-fluorouracil on proliferation of MCF-7 cells was associated with cell cycle arrest in G0/G1 phase or S phase and with induction of apoptosis. The inhibitory effect on proliferation of MCF-7 cells was enhanced when 1,25(OH)2D3 combined with 5-fluorouracil. The increase rate of apoptosis was higher than that of either 1,25(OH)2D3 or 5-fluorouracil alone . The inhibitory effect was hardly different when 1, 25 (OH) 2D3 combined with 5-fluorouracil. Either 1, 25(OH)2D3 or 5-fluorouracil alone could downregulate bcl-2 protein expression,bcl-2 protein expression did not show when 1,25(OH)2D3 combinedwith 5-fluorouracil.Conclusion 1,25(OH)2D3, and 5-fluorouracil synergisticallyinhibit proliferation and induce apoptosis in human breast cancercells, and 1,25(OH)2D3 combined with 5-fluorouracil can decreasethe dose of 5-fluorouracil.