title: Development of a bio-assay for estrogens using estrogen receptor alpha gene expression by MCF7 cells as biomarker.
abstract: Estrogenic endocrine disruptors (EDCs) have been identified in soil, food, air, and water, and may produce adverse health effects in both humans and wildlife. Various in vitro assays, including the E-screen that measures estrogen dependent proliferation of the MCF-7 human breast cancer cell line, have been developed and implemented to screen for environmental estrogenic EDCs. This study describes a new amendment to the well known E-screen. A direct ELISA to quantify ERalpha protein levels on MCF-7 cells cultured in a high through put 96-well format were validated as a biomarker for estrogenicity. The ELISA shows that there is an inverse correlation between ERalpha levels and 17beta-estradiol (E2) concentration (R(2) = 1). The detection range of the assay is between 1 and 1000 nM for E2. Results obtained with the ERalpha ELISA showed a good inverse correlation with total cellular LDH levels that is conventionally used to quantify MCF-7 cell proliferation. This ELISA was employed to assess environmental water extracts for estrogenicity.
authors.affiliation: Environmental Toxicology and Immunology Laboratory, Department of Medical Bioscience, University of Western Cape, Bellville, South Africa.
authors.forename: J C
authors.initials: JC
authors.lastname: Swart
authors.forename: E J
authors.initials: EJ
authors.lastname: Pool