The Influence Of Bisphenol A On Cell Proliferation And MRNA Expression Of Oncogene EphA2 & C-Myc In MCF-7 Breast Cancer Cells

Breast cancer was the most common malignant tumor for female.The exposure to envrionmental estrogens was thought as a main risk factor for the raising incidence of breast cancer worldwide.Environmental estrogens (EEs) was a large family of Environmental Endocrine Disruptors (EEDs),EES possess estrogen-mimicking properties and have been measured in human breast tissue and in human milk.Many researches have demonstrated that EEs such as DDT,PCBs and TCDD played an important role in the tumorigenesis of breast cancer.The widely used industrial monomer bisphenol-A (BPA) is a typical environmental estrogen found in polycarbonate plastics and epoxy resins.BPA mimics edogenous 17beta-estradiol(E2) by competitively binding and activating endogenous estrogen receptors(ERs).Some studies proved that BPA may affect the endocrine system and may cause developmental and reproductive disturbance, and even the carcinogenesis of breast cancer.However,the molecular mechanisms of which are involved in the action of BPA are still poorly understood.In this study,we explored the BPA effect on the cell growth of MCF-7 cells and the probable pathways are involved for the proliferation of MCF-7 cells induced by BPA.There are two sections in the study.Section 1:Cultured in BPA of different concentrations(10-4,10-5,10-6,10-7,10-8,10-9,10-10mol/L) for one week,MCF-7 cells were studied in cell proliferation by cell counting.We found that BPA could induce MCF-7 cell proliferation,and cell number in each concentration was more than that in solvent control(P<0.05).Section 2: Cultured in BPA of different concentrations(10-4,10-5,10-6,10-7,10-8mol/L) for 10 days,MCF-7 cells were studied in mRNA expression of oncogene EphA2 & c-Myc by RT-PCR.As a result,the mRNA expression of oncogene EphA2 & c-Myc in each concentration rose,especially the mRNA expression of c-Myc increased significantly compared with solvent control (P<0.05). Based on the study above,we draw a conclusion:BPA can induce MCF-7 cellproliferation,and this proliferation induced by BPA might attribute to higher mRNA expression of oncogene EphA2 and c-Myc in MCF-7 treated with BPA.Moreover MCF-7 cell proliferation was induced by BPA in a concentration range.