Mechanism Of Bisphenol A-induced Breast Cancer Cell Proliferation Via G Protein-coupled Receptor 30

BackgroundBisphenol A(BPA),an endocrine-disrupting chemical(EDC),is the most prevalent chemicals in daily-use material of packaging materials,dental sealants solid,and baby bottles.BPA exerts estrogen-like activity by interacting with the classical estrogen receptors(ERα and ERβ)or the G protein-coupled receptor(GPR30).In this regard,recent studies have shown that prenatal and neonatal exposure to BPA in low dose is linked to a wide variety of negative effects,including defects in male and female reproductive tracts,meiotic abnormalities in fetal oocytes,and complications during pregnancy.However,the mechanism is still unclear.ObjectiveThe transduction signaling pathways through which BPA influnces cell proliferation and migration in human breast cancer cells(MCF7 and SKBR3)were explored.MethodsMCF7 breast cancer cells(rich of estrogen receptor)and SKBR3 breast cancer cells(lack the classical ERs)were used as model system.GPR30 antagonist (ICI182780,G15),and agonists(PPT,DPN,G1)were used to find the effects of estrogen receptors on BPA induced proliferation.CCK-8 cell counting kit was applied to detect the cell viability under-treatment in different concentrations of BPA and time.Scratch test and Transwell migration assay was used to observe cell migration.Cell cycle was analyzed by flow cytometry.Protein and m RNA expression of GPR30 and c-fos was observed by RT-PCR and Western blot.The activation of ERK,Akt,PKA signaling pathway was detected by Western blot.AG-1478,PD98059,LY294002,MK2206,H89 were used as inhibitor of EGFR,ERK,PI3 K,Akt,PKA.Results 1.Cell viability was increased by BPA(10-7M-10-11M)after 12 h,but not in dose-dependent or time-dependent manner.2.Migration of MCF7 and SKBR3 cells were promoted by BPA.3.Protein and m RNA expression of GPR30 and c-fos were increased by BPA.However,its effect can be suppressed by G15.4.GPR30,not ERs was involved in BPA-induced cell proliferation.5.ERK and Akt signaling pathway were activated by BPA.However,BPA had no effect on PKA signaling pathway.6.Cell proliferation induced by BPA was decreased with pre-treatment of antagonists of GPR30,EGFR,ERK,PI3 K,Akt.7.Phosphorylation of ERK and Akt signaling pathway were decreased after blocking GPR30,EGFR,PI3 K.Conclusions GPR30-mediated EGFR-ERK and PI3K-Akt signaling pathways are involved in the regulation of bisphenol A-induced breast cancer cell proliferation.