title: Selective Human Estrogen Receptor Partial Agonists (ShERPAs) for Tamoxifen-Resistant Breast Cancer.
abstract: Almost 70% of breast cancers are estrogen receptor α (ERα) positive. Tamoxifen, a selective estrogen receptor modulator (SERM), represents the standard of care for many patients; however, 30-50% develop resistance, underlining the need for alternative therapeutics. Paradoxically, agonists at ERα such as estradiol (E2) have demonstrated clinical efficacy in patients with heavily treated breast cancer, although side effects in gynecological tissues are unacceptable. A drug that selectively mimics the actions of E2 in breast cancer therapy but minimizes estrogenic effects in other tissues is a novel, therapeutic alternative. We hypothesized that a selective human estrogen receptor partial agonist (ShERPA) at ERα would provide such an agent. Novel benzothiophene derivatives with nanomolar potency in breast cancer cell cultures were designed. Several showed partial agonist activity, with potency of 0.8-76 nM, mimicking E2 in inhibiting growth of tamoxifen-resistant breast cancer cell lines. Three ShERPAs were tested and validated in xenograft models of endocrine-independent and tamoxifen-resistant breast cancer, and in contrast to E2, ShERPAs did not cause significant uterine growth.
authors.affiliation: Department of Medicinal Chemistry & Pharmacognosy, University of Illinois at Chicago, 833 S Wood St, Chicago, Illinois 60612.
authors.forename: Rui
authors.initials: R
authors.lastname: Xiong
authors.affiliation: Department of Medicinal Chemistry & Pharmacognosy, University of Illinois at Chicago, 833 S Wood St, Chicago, Illinois 60612.
authors.forename: Hitisha K
authors.initials: HK
authors.lastname: Patel
authors.affiliation: Department of Medicinal Chemistry & Pharmacognosy, University of Illinois at Chicago, 833 S Wood St, Chicago, Illinois 60612.
authors.forename: Lauren M
authors.initials: LM
authors.lastname: Gutgesell
authors.affiliation: Department of Medicinal Chemistry & Pharmacognosy, University of Illinois at Chicago, 833 S Wood St, Chicago, Illinois 60612.
authors.forename: Jiong
authors.initials: J
authors.lastname: Zhao
authors.affiliation: Department of Medicinal Chemistry & Pharmacognosy, University of Illinois at Chicago, 833 S Wood St, Chicago, Illinois 60612.
authors.forename: Loruhama
authors.initials: L
authors.lastname: Delgado-Rivera
authors.affiliation: Department of Biopharmaceutical Sciences, University of Illinois at Chicago, 833 S Wood St, Chicago, Illinois 60612.
authors.forename: Thao N D
authors.initials: TND
authors.lastname: Pham
authors.affiliation: Department of Biopharmaceutical Sciences, University of Illinois at Chicago, 833 S Wood St, Chicago, Illinois 60612.
authors.forename: Huiping
authors.initials: H
authors.lastname: Zhao
authors.affiliation: Department of Chemistry, University of Illinois, Urbana Champaign, 600 South Mathews Avenue, Urbana, IL 61801.
authors.forename: Kathryn
authors.initials: K
authors.lastname: Carlson
authors.affiliation: Department of Chemistry, University of Illinois, Urbana Champaign, 600 South Mathews Avenue, Urbana, IL 61801.
authors.forename: Teresa
authors.initials: T
authors.lastname: Martin
authors.affiliation: Department of Chemistry, University of Illinois, Urbana Champaign, 600 South Mathews Avenue, Urbana, IL 61801.
authors.forename: John A
authors.initials: JA
authors.lastname: Katzenellenbogen
authors.affiliation: Department of Medicinal Chemistry & Pharmacognosy, University of Illinois at Chicago, 833 S Wood St, Chicago, Illinois 60612.
authors.forename: Terry W
authors.initials: TW
authors.lastname: Moore
authors.affiliation: Department of Biopharmaceutical Sciences, University of Illinois at Chicago, 833 S Wood St, Chicago, Illinois 60612.
authors.forename: Debra A
authors.initials: DA
authors.lastname: Tonetti
authors.affiliation: Department of Medicinal Chemistry & Pharmacognosy, University of Illinois at Chicago, 833 S Wood St, Chicago, Illinois 60612.
authors.forename: Gregory R J
authors.initials: GRJ
authors.lastname: Thatcher
mesh_terms: D000818:Animals; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy*; D045744:Cell Line, Tumor; D015195:Drug Design; D019008:Drug Resistance, Neoplasm / Q000187:drug effects*; D047628:Estrogen Receptor alpha / Q000187:drug effects; D005260:Female; D006801:Humans; D051379:Mice; D008958:Models, Molecular; D020845:Selective Estrogen Receptor Modulators / Q000627:therapeutic use*; D013329:Structure-Activity Relationship; D013629:Tamoxifen / Q000627:therapeutic use*; D014599:Uterus / Q000187:drug effects / Q000254:growth & development; D023041:Xenograft Model Antitumor Assays
chemical_list: D018931:Antineoplastic Agents, Hormonal; D047628:Estrogen Receptor alpha; D020845:Selective Estrogen Receptor Modulators; D013629:Tamoxifen