title: Endothelin-1 promotes epithelial-to-mesenchymal transition in human ovarian cancer cells.
abstract: Despite considerable efforts to improve early detection and advances in chemotherapy, metastatic relapses remain a major challenge in the management of ovarian cancer. The endothelin A receptor (ET(A)R)/endothelin-1 (ET-1) axis has been shown to have a significant role in ovarian carcinoma by promoting tumorigenesis. Here we show that the ET-1/ET(A)R autocrine pathway drives epithelial-to-mesenchymal transition (EMT) in ovarian tumor cells by inducing a fibroblastoid and invasive phenotype, down-regulation of E-cadherin, increased levels of beta-catenin, Snail, and other mesenchymal markers, and suppression of E-cadherin promoter activity. Activation of ET(A)R by ET-1 triggers an integrin-linked kinase (ILK)-mediated signaling pathway leading to glycogen synthase kinase-3beta (GSK-3beta) inhibition, Snail and beta-catenin stabilization, and regulation of transcriptional programs that control EMT. Transfection of dominant negative ILK or exposure to an ILK inhibitor suppresses the ET-1-induced phosphorylation of GSK-3beta as well as Snail and beta-catenin protein stability, activity, and invasiveness, indicating that ET-1/ET(A)R-induced EMT-promoting effects depend on ILK. ET(A)R blockade by specific antagonists or reduction by ET(A)R RNA interference reverses EMT and cell invasion by inhibiting autocrine signaling pathways. In ovarian carcinoma xenografts, ABT-627, a specific ET(A)R antagonist, suppresses EMT determinants and tumor growth. In human ovarian cancers, ET(A)R expression is associated with E-cadherin down-regulation, N-cadherin expression, and tumor grade. Collectively, these findings provide evidence of a critical role for the ET-1/ET(A)R axis during distinct steps of ovarian carcinoma progression and identify novel targets of therapeutic intervention.
authors.affiliation: Laboratory of Molecular Pathology and Ultrastructure, Regina Elena Cancer Institute, Rome, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Rosanò
authors.forename: Francesca
authors.initials: F
authors.lastname: Spinella
authors.forename: Valeriana
authors.initials: V
authors.lastname: Di Castro
authors.forename: Maria Rita
authors.initials: MR
authors.lastname: Nicotra
authors.forename: Shoukat
authors.initials: S
authors.lastname: Dedhar
authors.forename: Antonio Garcia
authors.initials: AG
authors.lastname: de Herreros
authors.forename: Pier Giorgio
authors.initials: PG
authors.lastname: Natali
authors.forename: Anna
authors.initials: A
authors.lastname: Bagnato
mesh_terms: D000818:Animals; D015152:Blotting, Northern; D015153:Blotting, Western; D015820:Cadherins / Q000235:genetics / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D015536:Down-Regulation; D065130:Endothelin A Receptor Antagonists; D019332:Endothelin-1 / Q000494:pharmacology*; D004791:Enzyme Inhibitors; D004847:Epithelial Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D005260:Female; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism / Q000473:pathology; D015972:Gene Expression Regulation, Neoplastic; D005799:Genes, Dominant; D038362:Glycogen Synthase Kinase 3 / Q000037:antagonists & inhibitors / Q000378:metabolism; D000071679:Glycogen Synthase Kinase 3 beta; D006801:Humans; D008156:Luciferases / Q000378:metabolism; D008648:Mesoderm / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D008819:Mice, Nude; D009361:Neoplasm Invasiveness; D010051:Ovarian Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D010641:Phenotype; D010766:Phosphorylation; D011401:Promoter Regions, Genetic / Q000235:genetics; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D021381:Protein Transport; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000494:pharmacology; D044022:Receptor, Endothelin A / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic; D014162:Transfection; D014407:Tumor Cells, Cultured; D023041:Xenograft Model Antitumor Assays; D051176:beta Catenin / Q000378:metabolism; D000099200:Scaffold Protein ILK
chemical_list: D015820:Cadherins; D065130:Endothelin A Receptor Antagonists; D019332:Endothelin-1; D004791:Enzyme Inhibitors; D038362:Glycogen Synthase Kinase 3; D000071679:Glycogen Synthase Kinase 3 beta; D008156:Luciferases; D017346:Protein Serine-Threonine Kinases; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D044022:Receptor, Endothelin A; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors; D051176:beta Catenin; D000099200:Scaffold Protein ILK; C000605506:GSK3B protein, human; C000605507:Gsk3b protein, mouse