Objective: To study the effect of 1, 25-dihydroxyvitamin D(3) [1, 25 (OH)(2)D(3)] on growth and apoptosis in breast cancer cell line MCF-7.
Methods: We compared cell numbers by using MTT method, analyzed cell cycle and apoptosis percentage by flow cytometric, observed cellular structure and ultrastructure, determined quantitatively apoptosis cells by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL), and detected expression of bcl-2 protein by Western Blot.
Results: Incubation with 1, 25 (OH)(2)D(3) 10(-7) mol/L, MCF-7 cells exhibited significant growth inhibition. Flow cytometric analysis indicated cell's G(0)/G(1) arrest along with increasing apoptotic peak and percentage. The action of cytotoxic drug Adr was strengthened. Western Blot showed that 1, 25 (OH)(2)D(3) could down-regulate bcl-2 protein expression.
Conclusions: 1, 25 (OH)(2)D(3) could be a new hormone for the treatment of breast cancer.