title: ETAR antagonist ZD4054 exhibits additive effects with aromatase inhibitors and fulvestrant in breast cancer therapy, and improves in vivo efficacy of anastrozole.
abstract: Endothelin-1 (ET-1) and endothelin A receptor (ETAR) contribute to the development and progression of breast carcinomas by modulating cell proliferation, angiogenesis, and anti-apoptosis. We investigated antitumoral effects of the specific ETAR antagonist ZD4054 in breast cancer cells and xenografts, and assessed antitumoral efficacy of the combinations of ZD4054 with aromatase inhibitors and fulvestrant. Gene expression changes were assessed by quantitative real-time PCR. Cell proliferation was measured using alamarBlue; migration and invasion assays were performed using modified Boyden chambers. Evaluating the antitumoral efficacy of ZD4054 in vivo, different breast cancer models were employed using nude mice xenografts. ZD4054 reduced ET-1 and ETAR expression in MCF-7, MDA-MB-231, and MDA-MB-468 breast cancer cells in a concentration-dependent manner. ZD4054 inhibited invasion by up to 37.1% (P = 0.022). Combinations of ZD4054 with either anastrozole or letrozole produced significant reductions in migration of aromatase-overexpressing MCF-7aro cells (P < 0.05). Combination of ZD4054 with fulvestrant reduced MCF-7 cell migration and invasion by 36.0% (P = 0.027) and 56.7% (P < 0.001), respectively, with effects significantly exceeding those seen with either compound alone. Regarding tumor volume reduction in vivo, ZD4054 (10 mg/kg) was equipotent to fulvestrant (200 mg/kg) and exhibited additive effects with anastrozole (0.5 mg/kg). These data are the first indicating that selective ETAR antagonism by ZD4054 displays antitumoral activity on breast cancer cells in vitro and in vivo. Our data strongly support a rationale for the clinical use of ZD4054 in combination with endocrine therapies.
authors: Department of Obstetrics and Gynecology, University Hospital of Münster, Albert-Schweitzer-Str. 33, 48129, Munster, Germany.
authors: Martin
authors: M
authors: Smollich
authors: Martin
authors: M
authors: Götte
authors: Jeanett
authors: J
authors: Fischgräbe
authors: Luciana F
authors: LF
authors: Macedo
authors: Angela
authors: A
authors: Brodie
authors: Shiuan
authors: S
authors: Chen
authors: Isabel
authors: I
authors: Radke
authors: Ludwig
authors: L
authors: Kiesel
authors: Pia
authors: P
authors: Wülfing
mesh_terms: D000077384:Anastrozole; D000818:Animals; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology*; D047072:Aromatase Inhibitors / Q000008:administration & dosage; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000201:enzymology / Q000235:genetics / Q000473:pathology; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D065130:Endothelin A Receptor Antagonists; D019332:Endothelin-1 / Q000378:metabolism; D004958:Estradiol / Q000008:administration & dosage / Q000031:analogs & derivatives; D004965:Estrogen Antagonists / Q000008:administration & dosage; D005260:Female; D000077267:Fulvestrant; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D009361:Neoplasm Invasiveness; D009570:Nitriles / Q000008:administration & dosage; D011759:Pyrrolidines / Q000008:administration & dosage; D044022:Receptor, Endothelin A / Q000378:metabolism; D013629:Tamoxifen / Q000008:administration & dosage; D013997:Time Factors; D014230:Triazoles / Q000008:administration & dosage; D047368:Tumor Burden / Q000187:drug effects; D023041:Xenograft Model Antitumor Assays
chemical_list: D047072:Aromatase Inhibitors; D065130:Endothelin A Receptor Antagonists; D019332:Endothelin-1; D004965:Estrogen Antagonists; D009570:Nitriles; D011759:Pyrrolidines; D044022:Receptor, Endothelin A; D014230:Triazoles; C511404:ZD4054; D013629:Tamoxifen; D000077267:Fulvestrant; D000077384:Anastrozole; D004958:Estradiol