title: Evaluation of a luciferase-based reporter assay as a screen for inhibitors of estrogen-ERα-induced proliferation of breast cancer cells.
abstract: Estrogens, acting through estrogen receptor α (ERα), stimulate breast cancer proliferation, making ERα an attractive drug target. Since 384-well format screens for inhibitors of proliferation can be challenging for some cells, inhibition of luciferase-based reporters is often used as a surrogate end point. To identify novel small-molecule inhibitors of 17β-estradiol (E(2))-ERα-stimulated cell proliferation, we established a cell-based screen for inhibitors of E(2)-ERα induction of an estrogen response element (ERE)(3)-luciferase reporter. Seventy-five "hits" were evaluated in tiered follow-up assays to identify where hits failed to progress and evaluate their effectiveness as inhibitors of E(2)-ERα-induced proliferation of breast cancer cells. Only 8 of 75 hits from the luciferase screen inhibited estrogen-induced proliferation of ERα-positive MCF-7 and T47D cells but not control ERα-negative MDA-MB-231 cells. Although 12% of compounds inhibited E(2)-ERα-stimulated proliferation in only one of the ERα-positive cell lines, 40% of compounds were toxic and inhibited growth of all the cell lines, and ~37% exhibited little or no ability to inhibit E(2)-ERα-stimulated cell proliferation. Representative compounds were evaluated in more detail, and a lead ERα inhibitor was identified.
authors.affiliation: Department of Biochemistry, University of Illinois, Urbana, IL, USA. nandrus2@illinois.edu
authors.forename: Neal
authors.initials: N
authors.lastname: Andruska
authors.forename: Chengjian
authors.initials: C
authors.lastname: Mao
authors.forename: Mathew
authors.initials: M
authors.lastname: Cherian
authors.forename: Chen
authors.initials: C
authors.lastname: Zhang
authors.forename: David J
authors.initials: DJ
authors.lastname: Shapiro
mesh_terms: D001681:Biological Assay; D001943:Breast Neoplasms / Q000378:metabolism*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004354:Drug Screening Assays, Antitumor / Q000379:methods*; D004958:Estradiol / Q000378:metabolism; D047628:Estrogen Receptor alpha / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D017930:Genes, Reporter; D057166:High-Throughput Screening Assays / Q000379:methods*; D006801:Humans; D008156:Luciferases; D020218:Response Elements
chemical_list: C506487:ESR1 protein, human; D047628:Estrogen Receptor alpha; D004958:Estradiol; D008156:Luciferases