title: A screening cascade to identify ERβ ligands.
abstract: The establishment of effective high throughput screening cascades to identify nuclear receptor (NR) ligands that will trigger defined, therapeutically useful sets of NR activities is of considerable importance. Repositioning of existing approved drugs with known side effect profiles can provide advantages because de novo drug design suffers from high developmental failure rates and undesirable side effects which have dramatically increased costs. Ligands that target estrogen receptor β (ERβ) could be useful in a variety of diseases ranging from cancer to neurological to cardiovascular disorders. In this context, it is important to minimize cross-reactivity with ERα, which has been shown to trigger increased rates of several types of cancer. Because of high sequence similarities between the ligand binding domains of ERα and ERβ, preferentially targeting one subtype can prove challenging. Here, we describe a sequential ligand screening approach comprised of complementary in-house assays to identify small molecules that are selective for ERβ. Methods include differential scanning fluorimetry, fluorescence polarization and a GAL4 transactivation assay. We used this strategy to screen several commercially-available chemical libraries, identifying thirty ERβ binders that were examined for their selectivity for ERβ versus ERα, and tested the effects of selected ligands in a prostate cancer cell proliferation assay. We suggest that this approach could be used to rapidly identify candidates for drug repurposing.
authors.affiliation: Genomic Medicine, Houston Methodist Research Institute (CSF, CB, XL, PSG, RAV, ALB, PW) and Center for Nuclear Receptors and Cell Signaling, University of Houston (AS, JAG, ALB, PW), Houston, Texas, USA .
authors.forename: Carly S
authors.initials: CS
authors.lastname: Filgueira
authors.affiliation: Genomic Medicine, Houston Methodist Research Institute (CSF, CB, XL, PSG, RAV, ALB, PW) and Center for Nuclear Receptors and Cell Signaling, University of Houston (AS, JAG, ALB, PW), Houston, Texas, USA .
authors.forename: Cindy
authors.initials: C
authors.lastname: Benod
authors.affiliation: Genomic Medicine, Houston Methodist Research Institute (CSF, CB, XL, PSG, RAV, ALB, PW) and Center for Nuclear Receptors and Cell Signaling, University of Houston (AS, JAG, ALB, PW), Houston, Texas, USA .
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Lou
authors.affiliation: Genomic Medicine, Houston Methodist Research Institute (CSF, CB, XL, PSG, RAV, ALB, PW) and Center for Nuclear Receptors and Cell Signaling, University of Houston (AS, JAG, ALB, PW), Houston, Texas, USA .
authors.forename: Prem S
authors.initials: PS
authors.lastname: Gunamalai
authors.affiliation: Genomic Medicine, Houston Methodist Research Institute (CSF, CB, XL, PSG, RAV, ALB, PW) and Center for Nuclear Receptors and Cell Signaling, University of Houston (AS, JAG, ALB, PW), Houston, Texas, USA .
authors.forename: Rosa A
authors.initials: RA
authors.lastname: Villagomez
authors.affiliation: Genomic Medicine, Houston Methodist Research Institute (CSF, CB, XL, PSG, RAV, ALB, PW) and Center for Nuclear Receptors and Cell Signaling, University of Houston (AS, JAG, ALB, PW), Houston, Texas, USA .
authors.forename: Anders
authors.initials: A
authors.lastname: Strom
authors.affiliation: Genomic Medicine, Houston Methodist Research Institute (CSF, CB, XL, PSG, RAV, ALB, PW) and Center for Nuclear Receptors and Cell Signaling, University of Houston (AS, JAG, ALB, PW), Houston, Texas, USA .
authors.forename: Jan-Åke
authors.initials: JÅ
authors.lastname: Gustafsson
authors.affiliation: Genomic Medicine, Houston Methodist Research Institute (CSF, CB, XL, PSG, RAV, ALB, PW) and Center for Nuclear Receptors and Cell Signaling, University of Houston (AS, JAG, ALB, PW), Houston, Texas, USA .
authors.forename: Anders L
authors.initials: AL
authors.lastname: Berkenstam
authors.affiliation: Genomic Medicine, Houston Methodist Research Institute (CSF, CB, XL, PSG, RAV, ALB, PW) and Center for Nuclear Receptors and Cell Signaling, University of Houston (AS, JAG, ALB, PW), Houston, Texas, USA .
authors.forename: Paul
authors.initials: P
authors.lastname: Webb
mesh_terms: D045744:Cell Line, Tumor; D004353:Drug Evaluation, Preclinical / Q000379:methods*; D047629:Estrogen Receptor beta / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008024:Ligands; D008297:Male; D011471:Prostatic Neoplasms / Q000378:metabolism / Q000473:pathology; D011485:Protein Binding; D054852:Small Molecule Libraries / Q000378:metabolism / Q000494:pharmacology; D013379:Substrate Specificity; D015533:Transcriptional Activation / Q000187:drug effects
chemical_list: D047629:Estrogen Receptor beta; D008024:Ligands; D054852:Small Molecule Libraries
keywords: Screening; chemical libraries; drugs; gene expression; gene regulation; nuclear receptors