Effects of Genistein on changes of osteoblastic biological function induced by breast cancer cells

Objective To investigate the effects of Genistein on changes of osteoblastic proliferation,differentiation and mineralization induced by breast cancer cells,and in order to observe whether Genistein regulates osteoblastic biological function in pathological condition with bone metastasis.Methods The osteoblasts harvested from calvaria of Sprague Dawley rats were cultured with 50% conditioned medium collected from two types of human breast cancer lines: MDA-MB-231 and MCF-7,and treated with different concentrations of Genistein: 5×10-7mol/L(G7)、5×10-8mol/L(G8)、5×10-9mol/L(G9).Then the proliferation was analyzed by MTT method,the alkaline phosphatase(ALP) activity was assessed by the p-nitrophenyl phosphate(PNPP) method,and the area of bone nodule formation was observed by alizarin red S(ARS) staining and measured to analyze the mineralization ability.Results Conditioned medium from MDA-MB-231 or MCF-7 significantly suppressed osteoblastic proliferation,while the proliferation on day 1,day 3 and day 5 was improved in the different extents when osteoblasts were treated with Genistein.Otherwise,conditioned medium significantly inhibited ALP activity on day 3,while compared with conditioned medium group,different concentrations of Genistein could increase the ALP activity of osteoblasts by 22.7%、32.4%、63.5% and 27.7%、32.0%、58.3%,respectively.Genistein also increased the area of bone nodule formation and improved osteoblastic mineralization ability inhibited by conditioned medium.Conclusion In pathological condition with bone metastasis,Genistein could promoto osteoblastic proliferation,differentiation and mineralization,improve osteoblastic biological function inhibited by breast cancer cells.