title: The thyroid hormone-αvβ3 integrin axis in ovarian cancer: regulation of gene transcription and MAPK-dependent proliferation.
abstract: Ovarian carcinoma is the fifth common cause of cancer death in women, despite advanced therapeutic approaches. αvβ3 integrin, a plasma membrane receptor, binds thyroid hormones (L-thyroxine, T4; 3,5,3'-triiodo-L-thyronine, T3) and is overexpressed in ovarian cancer. We have demonstrated selective binding of fluorescently labeled hormones to αvβ3-positive ovarian cancer cells but not to integrin-negative cells. Physiologically relevant T3 (1 nM) and T4 (100 nM) concentrations in OVCAR-3 (high αvβ3) and A2780 (low αvβ3) cells promoted αv and β3 transcription in association with basal integrin levels. This transcription was effectively blocked by RGD (Arg-Gly-Asp) peptide and neutralizing αvβ3 antibodies, excluding T3-induced β3 messenger RNA, suggesting subspecialization of T3 and T4 binding to the integrin receptor pocket. We have provided support for extracellular regulated kinase (ERK)-mediated transcriptional regulation of the αv monomer by T3 and of β3 monomer by both hormones and documented a rapid (30-120 min) and dose-dependent (0.1-1000 nM) ERK activation. OVCAR-3 cells and αvβ3-deficient HEK293 cells treated with αvβ3 blockers confirmed the requirement for an intact thyroid hormone-integrin interaction in ERK activation. In addition, novel data indicated that T4, but not T3, controls integrin's outside-in signaling by phosphorylating tyrosine 759 in the β3 subunit. Both hormones induced cell proliferation (cell counts), survival (Annexin-PI), viability (WST-1) and significantly reduced the expression of genes that inhibit cell cycle (p21, p16), promote mitochondrial apoptosis (Nix, PUMA) and tumor suppression (GDF-15, IGFBP-6), particularly in cells with high integrin expression. At last, we have confirmed that hypothyroid environment attenuated ovarian cancer growth using a novel experimental platform that exploited paired euthyroid and severe hypothyroid serum samples from human subjects. To conclude, our data define a critical role for thyroid hormones as potent αvβ3-ligands, driving ovarian cancer cell proliferation and suggest that disruption of this axis may present a novel treatment strategy in this aggressive disease.
authors.affiliation: Translational Hemato-Oncology Laboratory, The Hematology Institute and Blood Bank, Meir Medical Center, Kfar-Saba, Israel.|Department of Human Molecular Genetics and Biochemistry.|Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: E
authors.initials: E
authors.lastname: Shinderman-Maman
authors.affiliation: Translational Hemato-Oncology Laboratory, The Hematology Institute and Blood Bank, Meir Medical Center, Kfar-Saba, Israel.|Department of Human Molecular Genetics and Biochemistry.|Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: K
authors.initials: K
authors.lastname: Cohen
authors.affiliation: Translational Hemato-Oncology Laboratory, The Hematology Institute and Blood Bank, Meir Medical Center, Kfar-Saba, Israel.|Department of Human Molecular Genetics and Biochemistry.|Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: C
authors.initials: C
authors.lastname: Weingarten
authors.affiliation: Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.|Department of Endocrinology, Meir Medical Center, Kfar-Saba, Israel.
authors.forename: D
authors.initials: D
authors.lastname: Nabriski
authors.affiliation: Department of Endocrinology, Meir Medical Center, Kfar-Saba, Israel.
authors.forename: O
authors.initials: O
authors.lastname: Twito
authors.affiliation: Department of Endocrinology, Meir Medical Center, Kfar-Saba, Israel.
authors.forename: L
authors.initials: L
authors.lastname: Baraf
authors.affiliation: Radiation Oncology, Cleveland Clinic, Cleveland, OH, USA.
authors.forename: A
authors.initials: A
authors.lastname: Hercbergs
authors.affiliation: Department of Medicine, Albany Medical College, Albany, NY, USA.
authors.forename: P J
authors.initials: PJ
authors.lastname: Davis
authors.affiliation: Department of Human Molecular Genetics and Biochemistry.|Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: H
authors.initials: H
authors.lastname: Werner
authors.affiliation: Translational Hemato-Oncology Laboratory, The Hematology Institute and Blood Bank, Meir Medical Center, Kfar-Saba, Israel.|Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: M
authors.initials: M
authors.lastname: Ellis
authors.affiliation: Translational Hemato-Oncology Laboratory, The Hematology Institute and Blood Bank, Meir Medical Center, Kfar-Saba, Israel.|Department of Human Molecular Genetics and Biochemistry.|Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: O
authors.initials: O
authors.lastname: Ashur-Fabian
mesh_terms: D057134:Antibodies, Neutralizing / Q000494:pharmacology; D002455:Cell Division / Q000187:drug effects; D045744:Cell Line, Tumor; D003470:Culture Media / Q000494:pharmacology; D004789:Enzyme Activation; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D007037:Hypothyroidism / Q000097:blood; D039564:Integrin alphaV / Q000235:genetics / Q000378:metabolism; D039302:Integrin alphaVbeta3 / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology / Q000502:physiology*; D039661:Integrin beta3 / Q000235:genetics / Q000378:metabolism; D020935:MAP Kinase Signaling System / Q000187:drug effects / Q000502:physiology*; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D009376:Neoplasms, Hormone-Dependent / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D009842:Oligopeptides / Q000494:pharmacology; D010051:Ovarian Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D010766:Phosphorylation; D011499:Protein Processing, Post-Translational; D012333:RNA, Messenger / Q000096:biosynthesis; D012334:RNA, Neoplasm / Q000096:biosynthesis; D013974:Thyroxine / Q000097:blood / Q000494:pharmacology / Q000502:physiology*; D014158:Transcription, Genetic / Q000187:drug effects / Q000502:physiology; D014284:Triiodothyronine / Q000097:blood / Q000494:pharmacology / Q000502:physiology*
chemical_list: D057134:Antibodies, Neutralizing; D003470:Culture Media; D039564:Integrin alphaV; D039302:Integrin alphaVbeta3; D039661:Integrin beta3; D009363:Neoplasm Proteins; D009842:Oligopeptides; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D014284:Triiodothyronine; C047981:arginyl-glycyl-aspartic acid; D048049:Extracellular Signal-Regulated MAP Kinases; D013974:Thyroxine