title: Development of a recombinant human ovarian (BG1) cell line containing estrogen receptor α and β for improved detection of estrogenic/antiestrogenic chemicals.
abstract: Estrogenic endocrine-disrupting chemicals are found in environmental and biological samples, commercial and consumer products, food, and numerous other sources. Given their ubiquitous nature and potential for adverse effects, a critical need exists for rapidly detecting these chemicals. The authors developed an estrogen-responsive recombinant human ovarian (BG1Luc4E2) cell line recently accepted by the US Environmental Protection Agency (USEPA) and Organisation for Economic Co-operation and Development (OECD) as a bioanalytical method to detect estrogen receptor (ER) agonists/antagonists. Unfortunately, these cells appear to contain only 1 of the 2 known ER isoforms, ERα but not ERβ, and the differential ligand selectivity of these ERs indicates that the currently accepted screening method only detects a subset of total estrogenic chemicals. To improve the estrogen screening bioassay, BG1Luc4E2 cells were stably transfected with an ERβ expression plasmid and positive clones identified using ERβ-selective ligands (genistein and Br-ERβ-041). A highly responsive clone (BG1LucERβc9) was identified that exhibited greater sensitivity and responsiveness to ERβ-selective ligands than BG1Luc4E2 cells, and quantitative reverse-transcription polymerase chain reaction confirmed the presence of ERβ expression in these cells. Screening of pesticides and industrial chemicals identified chemicals that preferentially stimulated ERβ-dependent reporter gene expression. Together, these results not only demonstrate the utility of this dual-ER recombinant cell line for detecting a broader range of estrogenic chemicals than the current BG1Luc4E2 cell line, but screening with both cell lines allows identification of ERα- and ERβ-selective chemicals.
authors.affiliation: Department of Environmental Toxicology, University of California, Davis, California, USA.
authors.forename: Jennifer C
authors.initials: JC
authors.lastname: Brennan
authors.affiliation: Department of Environmental Toxicology, University of California, Davis, California, USA.
authors.forename: Arzoo
authors.initials: A
authors.lastname: Bassal
authors.affiliation: Department of Environmental Toxicology, University of California, Davis, California, USA.
authors.forename: Guochun
authors.initials: G
authors.lastname: He
authors.affiliation: Department of Environmental Toxicology, University of California, Davis, California, USA.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Denison
mesh_terms: D001681:Biological Assay; D002460:Cell Line; D052244:Endocrine Disruptors / Q000633:toxicity*; D004785:Environmental Pollutants / Q000633:toxicity*; D004965:Estrogen Antagonists / Q000633:toxicity*; D047628:Estrogen Receptor alpha / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism*; D047629:Estrogen Receptor beta / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism*; D004968:Estrogens, Non-Steroidal / Q000633:toxicity*; D005260:Female; D015870:Gene Expression / Q000187:drug effects; D019833:Genistein / Q000494:pharmacology; D006801:Humans; D010053:Ovary / Q000166:cytology / Q000378:metabolism*; D010575:Pesticides / Q000633:toxicity; D010957:Plasmids / Q000235:genetics; D016133:Polymerase Chain Reaction; D014162:Transfection
chemical_list: C506487:ESR1 protein, human; D052244:Endocrine Disruptors; D004785:Environmental Pollutants; D004965:Estrogen Antagonists; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D004968:Estrogens, Non-Steroidal; D010575:Pesticides; D019833:Genistein
keywords: BG1Luc ER TA; Environmental screening; Estrogen receptor bioassay; Estrogenic chemicals