[Detection of estrogenic effects of nonylphenol and bisphenol A in vitro reporter gene-based assays].

ABSTRACT

OBJECTIVE: To explore the estrogenic effects and disruptive mechanism of NP and BPA by reporter gene-based assays we developed. METHODS: pERE-Luc plamid was generated by inserting estrogen response element (ERE) fragment into MCS of pGL3-promoter vector. MCF7 cells were cotransfected with pERE-Luc and phRL-SV40 using Sofast transfection reagent. The cells then treated with 17beta-estradiol (E2), tamoxifen (Tam), nonylphenol(NP) and bisphenol A (BPA) and expression of the repoter gene in the cell lysates was assayed using Dual-Lucferase reporter assay system. RESULTS: The pERE-Luc plasmid was constructed. Luciferase activities of MCF7 cells transfected pERE-Luc showed dose-responed realitionship with E2. 1 x 10(-11) mol/L E2 could induce the expression of reporter gene and 1 x 10(-9) mol/L E2 resulted in the largest luciferase activity. E2 couldn't induce the luciferase activity without pERE-Luc. Tam is a complete antagonist, inhibited the E2-induced luciferase expression. NP induced the luciferase activity at concertrations > 1 x 10(-6) mol/L, BPA induced the luciferase activity at concertrations > 1 x 10(-6) mol/L. The estrogenic activity of NP was more than BPA. CONCLUSION: The assay we established is usful, NP and BPA showed estrogenic activities.