1
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Promising Perspectives of the Antiproliferative GPER Inverse Agonist ERα17p in Breast Cancer. Cells 2023; 12:cells12040653. [PMID: 36831322 PMCID: PMC9954065 DOI: 10.3390/cells12040653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 02/07/2023] [Accepted: 02/14/2023] [Indexed: 02/22/2023] Open
Abstract
The estrogen receptor α (ERα) corresponds to a large platform in charge of the recruitment of a panel of molecules, including steroids and related heterocyclic derivatives, oligonucleotides, peptides and proteins. Its 295-311 region is particularly targeted by post-translational modifications, suggesting that it could be crucial for the control of transcription. In addition to anionic phospholipids, the ERα 295-311 fragment interacts with Ca2+-calmodulin, the heat shock protein 70 (Hsp70), ERα and possibly importins. More recently, we have demonstrated that it is prone to interacting with the G-protein-coupled estrogen receptor (GPER). In light of these observations, the pharmacological profile of the corresponding peptide, namely ERα17p, has been explored in breast cancer cells. Remarkably, it exerts apoptosis through GPER and induces a significant decrease (more than 50%) of the size of triple-negative breast tumor xenografts in mice. Herein, we highlight not only the promising therapeutic perspectives in the use of the first peptidic GPER modulator ERα17p, but also the opportunity to modulate GPER for clinical purposes.
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2
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Identification of a human estrogen receptor α tetrapeptidic fragment with dual antiproliferative and anti-nociceptive action. Sci Rep 2023; 13:1326. [PMID: 36693877 PMCID: PMC9873809 DOI: 10.1038/s41598-023-28062-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 01/12/2023] [Indexed: 01/25/2023] Open
Abstract
The synthetic peptide ERα17p (sequence: PLMIKRSKKNSLALSLT), which corresponds to the 295-311 region of the human estrogen receptor α (ERα), induces apoptosis in breast cancer cells. In mice and at low doses, it promotes not only the decrease of the size of xenografted triple-negative human breast tumors, but also anti-inflammatory and anti-nociceptive effects. Recently, we have shown that these effects were due to its interaction with the seven-transmembrane G protein-coupled estrogen receptor GPER. Following modeling studies, the C-terminus of this peptide (sequence: NSLALSLT) remains compacted at the entrance of the GPER ligand-binding pocket, whereas its N-terminus (sequence: PLMI) engulfs in the depth of the same pocket. Thus, we have hypothesized that the PLMI motif could support the pharmacological actions of ERα17p. Here, we show that the PLMI peptide is, indeed, responsible for the GPER-dependent antiproliferative and anti-nociceptive effects of ERα17p. By using different biophysical approaches, we demonstrate that the NSLALSLT part of ERα17p is responsible for aggregation. Overall, the tetrapeptide PLMI, which supports the action of the parent peptide ERα17p, should be considered as a hit for the synthesis of new GPER modulators with dual antiproliferative and anti-nociceptive actions. This study highlights also the interest to modulate GPER for the control of pain.
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3
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Kalyvianaki K, Panagiotopoulos AA, Patentalaki M, Castanas E, Kampa M. Importins involved in the nuclear transportation of steroid hormone receptors: In silico and in vitro data. Front Endocrinol (Lausanne) 2022; 13:954629. [PMID: 36147566 PMCID: PMC9487861 DOI: 10.3389/fendo.2022.954629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 08/10/2022] [Indexed: 11/17/2022] Open
Abstract
The nuclear receptor superfamily (NRS) consists of 48 receptors for lipophilic substances and is divided into 7 different subfamilies, with subfamily 3 comprising steroid hormone receptors. Several nuclear receptors usually bind their cognate ligands in the cytosol and the complex (mono- or dimerized) is transported to the nucleus, where it acts as a transcription initiating factor for a number of genes. The general structure of nuclear receptors consists of an N-terminal activating domain (A/B), important for the binding of activating or inhibitory co-factors, the DNA-binding domain (C), responsible for the association of the receptor-ligand-co-factor complex to the nucleus, the ligand-AF2 domain (E/F), where ligand binding occurs as well as that of ligand-dependent activating/inhibiting factors, and a flexible/non-structured domain (D), linking the DBD and LBD, called hinge region, on which a significant number of post-translational modifications occur. This hinge domain, for the sub-class of steroid receptors, is a non-structured domain and was reported as mainly responsible for the nuclear transport of steroid receptors, since it contains a specific amino acid sequence (Nuclear Localization Signal-NLS), recognized by importin α. In addition to the importin α/β complex, a number of other importins have been discovered and reported to be responsible for the nuclear transport of a number of significant proteins; however, the corresponding recognition sequences for these importins have not been identified. Recently, we have reported the identification of the NLS sequences for importins 4, 5 and 7. In this work, we provide in silico data, followed by experimental in vitro validation, showing that these alternative importins are responsible for the nuclear transportation of steroid hormone receptors such as ERα, AR and PR, and therefore they may consist of alternative targets for the pharmacological manipulation of steroid hormone actions. Moreover, we provide additional in silico data for the hinge region of steroid hormone receptors which is highly enriched with NLS sequences for importins 4, 5 and 7, in addition to the recognition NLS for importin α/β.
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Affiliation(s)
| | | | | | - Elias Castanas
- Laboratory of Experimental Endocrinology, School of Medicine, University of Crete, Heraklion, Greece
| | - Marilena Kampa
- Laboratory of Experimental Endocrinology, School of Medicine, University of Crete, Heraklion, Greece
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4
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Acramel A, Jacquot Y. Deciphering of a Putative GPER Recognition Domain in ERα and ERα36. Front Endocrinol (Lausanne) 2022; 13:943343. [PMID: 35846328 PMCID: PMC9279910 DOI: 10.3389/fendo.2022.943343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 06/06/2022] [Indexed: 11/25/2022] Open
Affiliation(s)
- Alexandre Acramel
- CiTCoM laboratory, Centre National de la Recherche Scientifique (CNRS) Unité Mixte de Recherche (UMR) 8038, Institut National de la Santé et de la Recherche Médicale (INSERM) U1268, Faculty of Pharmacy of Paris, Université Paris Cité, Paris, France
- Department of Pharmacy, Institut Curie, Paris, France
| | - Yves Jacquot
- CiTCoM laboratory, Centre National de la Recherche Scientifique (CNRS) Unité Mixte de Recherche (UMR) 8038, Institut National de la Santé et de la Recherche Médicale (INSERM) U1268, Faculty of Pharmacy of Paris, Université Paris Cité, Paris, France
- *Correspondence: Yves Jacquot,
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5
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Mallet C, Boudieu L, Lamoine S, Coudert C, Jacquot Y, Eschalier A. The Antitumor Peptide ERα17p Exerts Anti-Hyperalgesic and Anti-Inflammatory Actions Through GPER in Mice. Front Endocrinol (Lausanne) 2021; 12:578250. [PMID: 33815268 PMCID: PMC8011567 DOI: 10.3389/fendo.2021.578250] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 02/08/2021] [Indexed: 12/12/2022] Open
Abstract
Persistent inflammation and persistent pain are major medical, social and economic burdens. As such, related pharmacotherapy needs to be continuously improved. The peptide ERα17p, which originates from a part of the hinge region/AF2 domain of the human estrogen receptor α (ERα), exerts anti-proliferative effects in breast cancer cells through a mechanism involving the hepta-transmembrane G protein-coupled estrogen receptor (GPER). It is able to decrease the size of xenografted human breast tumors, in mice. As GPER has been reported to participate in pain and inflammation, we were interested in exploring the potential of ERα17p in this respect. We observed that the peptide promoted anti-hyperalgesic effects from 2.5 mg/kg in a chronic mice model of paw inflammation induced by the pro-inflammatory complete Freund's adjuvant (CFA). This action was abrogated by the specific GPER antagonist G-15, leading to the conclusion that a GPER-dependent mechanism was involved. A systemic administration of a Cy5-labeled version of the peptide allowed its detection in both, the spinal cord and brain. However, ERα17p-induced anti-hyperalgesia was detected at the supraspinal level, exclusively. In the second part of the study, we have assessed the anti-inflammatory action of ERα17p in mice using a carrageenan-evoked hind-paw inflammation model. A systemic administration of ERα17p at a dose of 2.5 mg/kg was responsible for reduced paw swelling. Overall, our work strongly suggests that GPER inverse agonists, including ERα17p, could be used to control hyperalgesia and inflammation.
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Affiliation(s)
- Christophe Mallet
- Université Clermont Auvergne, INSERM, NEURO-DOL Basics & Clinical Pharmacology of Pain, Clermont-Ferrand, France
- ANALGESIA Institute, Faculty of Medicine, Clermont-Ferrand, France
- *Correspondence: Christophe Mallet,
| | - Ludivine Boudieu
- Université Clermont Auvergne, INSERM, NEURO-DOL Basics & Clinical Pharmacology of Pain, Clermont-Ferrand, France
- ANALGESIA Institute, Faculty of Medicine, Clermont-Ferrand, France
| | - Sylvain Lamoine
- Université Clermont Auvergne, INSERM, NEURO-DOL Basics & Clinical Pharmacology of Pain, Clermont-Ferrand, France
- ANALGESIA Institute, Faculty of Medicine, Clermont-Ferrand, France
| | - Catherine Coudert
- Université Clermont Auvergne, INSERM, NEURO-DOL Basics & Clinical Pharmacology of Pain, Clermont-Ferrand, France
- ANALGESIA Institute, Faculty of Medicine, Clermont-Ferrand, France
| | - Yves Jacquot
- Université de Paris, Faculté de Pharmacie de Paris, CiTCoM, CNRS UMR 8038, INSERM U1268, Paris, France
| | - Alain Eschalier
- Université Clermont Auvergne, INSERM, NEURO-DOL Basics & Clinical Pharmacology of Pain, Clermont-Ferrand, France
- ANALGESIA Institute, Faculty of Medicine, Clermont-Ferrand, France
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6
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Pathological Maintenance and Evolution of Breast Cancer: The Convergence of Irreversible Biological Actions of ER Alpha. ENDOCRINES 2020. [DOI: 10.3390/endocrines2010001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Estrogen receptor alpha (ERα) is a modulator of breast cancer maintenance and evolution. Hence, analysis of underlying mechanisms by which ERα operates is of importance for the improvement of the hormonal therapy of the disease. This review focuses on the irreversible character of the mechanism of action of ERα, which also concerns other members of the steroid hormones receptors family. ERα moves in permanence between targets localized especially at the chromatin level to accomplish gene transcriptions imposed by the estrogenic ligands and specific antagonists. Receptor association as at the plasma membrane, where it interacts with other recruitment sites, extends its regulatory potency to growth factors and related peptides through activation of signal transductions pathways. If the latter procedure is suitable for the transcriptions in which the receptor operates as a coregulator of another transcription factor, it is of marginal influence with regard to the direct estrogenic regulation procedure, especially in the context of the present review. Irreversibility of the successive steps of the underlying transcription cycle guarantees maintenance of homeostasis and evolution according to vital necessities. To justify this statement, reported data are essentially described in a holistic view rather than in the context of exhaustive analysis of a molecular event contributing to a specific function as well as in a complementary perspective to elaborate new therapeutic approaches with antagonistic potencies against those tumors promoting ERα properties.
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7
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Trichet M, Lappano R, Belnou M, Salazar Vazquez LS, Alves I, Ravault D, Sagan S, Khemtemourian L, Maggiolini M, Jacquot Y. Interaction of the Anti-Proliferative GPER Inverse Agonist ERα17p with the Breast Cancer Cell Plasma Membrane: From Biophysics to Biology. Cells 2020; 9:E447. [PMID: 32075246 PMCID: PMC7072814 DOI: 10.3390/cells9020447] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 02/03/2020] [Accepted: 02/11/2020] [Indexed: 01/02/2023] Open
Abstract
The peptide ERα17p, which corresponds to the 295-311 fragment of the hinge/AF2 domains of the human estrogen receptor α (ERα), exerts apoptosis in breast cancer cells through a mechanism involving the G protein-coupled estrogen-dependent receptor GPER. Besides this receptor-mediated mechanism, we have detected a direct interaction (Kd value in the micromolar range) of this peptide with lipid vesicles mimicking the plasma membrane of eukaryotes. The reversible and not reversible pools of interacting peptide may correspond to soluble and aggregated membrane-interacting peptide populations, respectively. By using circular dichroism (CD) spectroscopy, we have shown that the interaction of the peptide with this membrane model was associated with its folding into β sheet. A slight leakage of the 5(6)-fluorescein was also observed, indicating lipid bilayer permeability. When the peptide was incubated with living breast cancer cells at the active concentration of 10 μM, aggregates were detected at the plasma membrane under the form of spheres. This insoluble pool of peptide, which seems to result from a fibrillation process, is internalized in micrometric vacuoles under the form of fibrils, without evidence of cytotoxicity, at least at the microscopic level. This study provides new information on the interaction of ERα17p with breast cancer cell membranes as well as on its mechanism of action, with respect to direct membrane effects.
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Affiliation(s)
- Michaël Trichet
- Institut de Biologie Paris-Seine (IBPS), Service de Microscopie éLectronique (IBPS-SME), Sorbonne Université, CNRS, 75005 Paris, France;
| | - Rosamaria Lappano
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, 87036 Rende, Italy;
| | - Mathilde Belnou
- Laboratoire des Biomolécules, LBM, CNRS UMR 7203, Sorbonne Université, Ecole Normale Supérieure, PSL University, 75005 Paris, France; (M.B.); (L.S.S.V.); (D.R.); (S.S.); (L.K.)
| | - Lilian Shadai Salazar Vazquez
- Laboratoire des Biomolécules, LBM, CNRS UMR 7203, Sorbonne Université, Ecole Normale Supérieure, PSL University, 75005 Paris, France; (M.B.); (L.S.S.V.); (D.R.); (S.S.); (L.K.)
| | - Isabel Alves
- Institute of Chemistry & Biology of Membranes & Nanoobjects (CBMN), CNRS UMR 5248, Université de Bordeaux, Institut Polytechnique Bordeaux, 33600 Pessac, France;
| | - Delphine Ravault
- Laboratoire des Biomolécules, LBM, CNRS UMR 7203, Sorbonne Université, Ecole Normale Supérieure, PSL University, 75005 Paris, France; (M.B.); (L.S.S.V.); (D.R.); (S.S.); (L.K.)
| | - Sandrine Sagan
- Laboratoire des Biomolécules, LBM, CNRS UMR 7203, Sorbonne Université, Ecole Normale Supérieure, PSL University, 75005 Paris, France; (M.B.); (L.S.S.V.); (D.R.); (S.S.); (L.K.)
| | - Lucie Khemtemourian
- Laboratoire des Biomolécules, LBM, CNRS UMR 7203, Sorbonne Université, Ecole Normale Supérieure, PSL University, 75005 Paris, France; (M.B.); (L.S.S.V.); (D.R.); (S.S.); (L.K.)
- Institute of Chemistry & Biology of Membranes & Nanoobjects (CBMN), CNRS UMR 5248, Université de Bordeaux, Institut Polytechnique Bordeaux, 33600 Pessac, France;
| | - Marcello Maggiolini
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, 87036 Rende, Italy;
| | - Yves Jacquot
- Laboratoire des Biomolécules, LBM, CNRS UMR 7203, Sorbonne Université, Ecole Normale Supérieure, PSL University, 75005 Paris, France; (M.B.); (L.S.S.V.); (D.R.); (S.S.); (L.K.)
- Cibles Thérapeutiques et Conception de Médicaments (CiTCoM), CNRS UMR 8038, U1268 INSERM, Faculté des Sciences Pharmaceutiques et Biologiques, Université Paris Descartes, 75006 Paris, France
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8
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Lappano R, Mallet C, Rizzuti B, Grande F, Galli GR, Byrne C, Broutin I, Boudieu L, Eschalier A, Jacquot Y, Maggiolini M. The Peptide ERα17p Is a GPER Inverse Agonist that Exerts Antiproliferative Effects in Breast Cancer Cells. Cells 2019; 8:cells8060590. [PMID: 31207943 PMCID: PMC6627388 DOI: 10.3390/cells8060590] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 06/13/2019] [Indexed: 12/18/2022] Open
Abstract
The inhibition of the G protein-coupled estrogen receptor (GPER) offers promising perspectives for the treatment of breast tumors. A peptide corresponding to part of the hinge region/AF2 domain of the human estrogen receptor α (ERα17p, residues 295–311) exerts anti-proliferative effects in various breast cancer cells including those used as triple negative breast cancer (TNBC) models. As preliminary investigations have evoked a role for the GPER in the mechanism of action of this peptide, we focused our studies on this protein using SkBr3 breast cancer cells, which are ideal for GPER evaluation. ERα17p inhibits cell growth by targeting membrane signaling. Identified as a GPER inverse agonist, it co-localizes with GPER and induces the proteasome-dependent downregulation of GPER. It also decreases the level of pEGFR (phosphorylation of epidermal growth factor receptor), pERK1/2 (phosphorylation of extracellular signal-regulated kinase), and c-fos. ERα17p is rapidly distributed in mice after intra-peritoneal injection and is found primarily in the mammary glands. The N-terminal PLMI motif, which presents analogies with the GPER antagonist PBX1, reproduces the effect of the whole ERα17p. Thus, this motif seems to direct the action of the entire peptide, as highlighted by docking and molecular dynamics studies. Consequently, the tetrapeptide PLMI, which can be claimed as the first peptidic GPER disruptor, could open new avenues for specific GPER modulators.
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Affiliation(s)
- Rosamaria Lappano
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, 87036 Rende, Italy.
| | - Christophe Mallet
- NEURO-DOL Basics & Clinical Pharmacology of Pain, INSERM, CHU, Université Clermont Auvergne, F-63000 Clermont-Ferrand, France.
- ANALGESIA Institute, Université Clermont Auvergne, F-63000 Clermont-Ferrand, France.
| | - Bruno Rizzuti
- CNR-NANOTEC, Licryl-UOS Cosenza and CEMIF.Cal, Department of Physics, University of Calabria, 87036 Rende, Italy.
| | - Fedora Grande
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, 87036 Rende, Italy.
| | - Giulia Raffaella Galli
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, 87036 Rende, Italy.
| | - Cillian Byrne
- Laboratoire des Biomolécules (LBM), CNRS-UMR 7203, Sorbonne University, Ecole Normale Supérieure, 75252 Paris Cedex 05, France.
| | - Isabelle Broutin
- Cibles Thérapeutiques et Conception de Médicaments (CiTCoM), CNRS-UMR 8038, Faculté des Sciences Pharmaceutiques et Biologiques, Université Paris Descartes, 75270 Paris Cedex 06, France.
| | - Ludivine Boudieu
- NEURO-DOL Basics & Clinical Pharmacology of Pain, INSERM, CHU, Université Clermont Auvergne, F-63000 Clermont-Ferrand, France.
- ANALGESIA Institute, Université Clermont Auvergne, F-63000 Clermont-Ferrand, France.
| | - Alain Eschalier
- NEURO-DOL Basics & Clinical Pharmacology of Pain, INSERM, CHU, Université Clermont Auvergne, F-63000 Clermont-Ferrand, France.
- ANALGESIA Institute, Université Clermont Auvergne, F-63000 Clermont-Ferrand, France.
| | - Yves Jacquot
- Laboratoire des Biomolécules (LBM), CNRS-UMR 7203, Sorbonne University, Ecole Normale Supérieure, 75252 Paris Cedex 05, France.
| | - Marcello Maggiolini
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, 87036 Rende, Italy.
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9
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Byrne C, Belnou M, Baulieu E, Lequin O, Jacquot Y. Electronic circular dichroism and nuclear magnetic resonance studies of peptides derived from the FKBP52‐interacting β‐turn of the hERα ligand‐binding domain. Pept Sci (Hoboken) 2019. [DOI: 10.1002/pep2.24113] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Cillian Byrne
- Sorbonne Université, Ecole Normale SupérieurePSL University, CNRS UMR 7203, Laboratoire des Biomolécules Paris France
- Institut Baulieu, Université Paris‐SaclayINSERM UMR 1195, Neuroprotection and Neuroregeneration Le Kremlin Bicêtre France
| | - Mathilde Belnou
- Sorbonne Université, Ecole Normale SupérieurePSL University, CNRS UMR 7203, Laboratoire des Biomolécules Paris France
| | - Etienne‐Emile Baulieu
- Institut Baulieu, Université Paris‐SaclayINSERM UMR 1195, Neuroprotection and Neuroregeneration Le Kremlin Bicêtre France
| | - Olivier Lequin
- Sorbonne Université, Ecole Normale SupérieurePSL University, CNRS UMR 7203, Laboratoire des Biomolécules Paris France
| | - Yves Jacquot
- Sorbonne Université, Ecole Normale SupérieurePSL University, CNRS UMR 7203, Laboratoire des Biomolécules Paris France
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10
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Jacquot Y, Spaggiari D, Schappler J, Lesniewska E, Rudaz S, Leclercq G. ERE-dependent transcription and cell proliferation: Independency of these two processes mediated by the introduction of a sulfone function into the weak estrogen estrothiazine. Eur J Pharm Sci 2017; 109:169-181. [PMID: 28754571 DOI: 10.1016/j.ejps.2017.07.026] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 07/18/2017] [Accepted: 07/24/2017] [Indexed: 02/07/2023]
Abstract
The synthetic coumestrol derivative 6,12-dihydro-3-methoxy-1-benzopyrano[3,4-b][1,4]benzothiazin-6-one (estrothiazine, ESTZ) has been identified as a weak estrogen receptor α (ERα) ligand unable to compete with tritiated estradiol. The biological activity of this compound, supported by a methoxy group in position 3, seems mainly to result from its capacity to activate ERα dimerization without any participation of coactivators. In support of this view and referring to conventional estrogens, an ESTZ metabolism study conducted with hepatic human microsomes failed to provide any argument in favour of an estrogenic activity dependent on a metabolic conversion of the compound into hydroxylated metabolites with strong receptor activation ability. Interestingly, we failed to detect any oxidation of the sulfur atom of the compound. In the light of pharmacological literature data concerning sulfonylation, we assessed ERα-mediated activities generated by two sulfonylated ESTZ derivatives in which the methoxy group that plays a key role in its mechanism of action was maintained or removed. Sulfonylated ESTZ, even in its demethoxylated form, induced ERE-mediated transcriptions in MCF-7 breast cancer cells, without affecting the ERα turnover rate. In contrast to ESTZ, this compound failed to enhance the proliferation of ERα-positive breast cancer cells, suggesting that its sulfone function confers upon the receptor a capacity to elicit some of the known characteristics associated with estrogenic responses. Moreover, we demonstrated that this sulfone may contribute to ERα dimerization without any requirement of the methoxy group. Nevertheless, it seems to cooperate with this group, as reflected by a weak ability of the sulfonylated form of ESTZ to compete with tritiated estradiol for ERα-binding. Assessment of the docking of this compound within the ligand-binding domain of the receptor by molecular dynamics provided an explanation for this observation since the sulfone is engulfed in a small hydrophobic pocket involving the residues Leu-346, Leu-349, Ala-350 and Leu-384, also known to recruit coactivators. This work not only reports the sulfone functional group as a pharmacophore for estrogenic activity, but also opens new perspectives for the development of estrogenic molecules with therapeutic purpose and devoid of proliferative side effects.
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Affiliation(s)
- Yves Jacquot
- Sorbonne University - UPMC Univ Paris 06, Ecole Normale Supérieure, PSL Research University, Département de Chimie, CNRS UMR 7203 LBM, 4 Place Jussieu, 75005 Paris, France.
| | - Dany Spaggiari
- Section des Sciences Pharmaceutiques (EPGL), University of Geneva, University of Lausanne, rue Michel Servet 1, 1211 Geneva 4, Switzerland
| | - Julie Schappler
- Section des Sciences Pharmaceutiques (EPGL), University of Geneva, University of Lausanne, rue Michel Servet 1, 1211 Geneva 4, Switzerland
| | - Eric Lesniewska
- ICB, CNRS UMR 6303, University de Bourgogne Franche-Comté, 9, avenue Savary, 21078 Dijon, France
| | - Serge Rudaz
- Section des Sciences Pharmaceutiques (EPGL), University of Geneva, University of Lausanne, rue Michel Servet 1, 1211 Geneva 4, Switzerland
| | - Guy Leclercq
- Laboratory J.C. Heuson de Cancérologie Mammaire, Institut Jules Bordet, 1, rue Héger Bordet, Brussels 1000, Belgium.
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11
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Byrne C, Henen MA, Belnou M, Cantrelle FX, Kamah A, Qi H, Giustiniani J, Chambraud B, Baulieu EE, Lippens G, Landrieu I, Jacquot Y. A β-Turn Motif in the Steroid Hormone Receptor’s Ligand-Binding Domains Interacts with the Peptidyl-prolyl Isomerase (PPIase) Catalytic Site of the Immunophilin FKBP52. Biochemistry 2016; 55:5366-76. [DOI: 10.1021/acs.biochem.6b00506] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Cillian Byrne
- Sorbonne Universités, UPMC Univ Paris 06, Ecole Normale Supérieure,
PSL Research University, CNRS UMR 7203, Laboratoire des Biomolécules, 4, place Jussieu, 75252 Paris Cedex 05, France
- Institut Baulieu, INSERM UMR 1195, Neuroprotection
and Neuroregeneration,
Université Paris-Saclay, Bât. Gregory Pincus, 80, rue du Général Leclerc, 94276 Le Kremlin Bicêtre Cedex, France
| | - Morkos A. Henen
- CNRS, UMR 8576,
Glycobiologie Structurale et Fonctionnelle, Université des
Sciences et Technologies de Lille 1, 59655 Villeneuve d’Ascq Cedex, France
| | - Mathilde Belnou
- Sorbonne Universités, UPMC Univ Paris 06, Ecole Normale Supérieure,
PSL Research University, CNRS UMR 7203, Laboratoire des Biomolécules, 4, place Jussieu, 75252 Paris Cedex 05, France
| | - François-Xavier Cantrelle
- CNRS, UMR 8576,
Glycobiologie Structurale et Fonctionnelle, Université des
Sciences et Technologies de Lille 1, 59655 Villeneuve d’Ascq Cedex, France
| | - Amina Kamah
- CNRS, UMR 8576,
Glycobiologie Structurale et Fonctionnelle, Université des
Sciences et Technologies de Lille 1, 59655 Villeneuve d’Ascq Cedex, France
| | - Haoling Qi
- CNRS, UMR 8576,
Glycobiologie Structurale et Fonctionnelle, Université des
Sciences et Technologies de Lille 1, 59655 Villeneuve d’Ascq Cedex, France
| | - Julien Giustiniani
- Institut Baulieu, INSERM UMR 1195, Neuroprotection
and Neuroregeneration,
Université Paris-Saclay, Bât. Gregory Pincus, 80, rue du Général Leclerc, 94276 Le Kremlin Bicêtre Cedex, France
| | - Béatrice Chambraud
- Institut Baulieu, INSERM UMR 1195, Neuroprotection
and Neuroregeneration,
Université Paris-Saclay, Bât. Gregory Pincus, 80, rue du Général Leclerc, 94276 Le Kremlin Bicêtre Cedex, France
| | - Etienne-Emile Baulieu
- Institut Baulieu, INSERM UMR 1195, Neuroprotection
and Neuroregeneration,
Université Paris-Saclay, Bât. Gregory Pincus, 80, rue du Général Leclerc, 94276 Le Kremlin Bicêtre Cedex, France
| | - Guy Lippens
- CNRS, UMR 8576,
Glycobiologie Structurale et Fonctionnelle, Université des
Sciences et Technologies de Lille 1, 59655 Villeneuve d’Ascq Cedex, France
- LISBP,
Université
de Toulouse, CNRS, INRA, INSA, Toulouse, France
| | - Isabelle Landrieu
- CNRS, UMR 8576,
Glycobiologie Structurale et Fonctionnelle, Université des
Sciences et Technologies de Lille 1, 59655 Villeneuve d’Ascq Cedex, France
| | - Yves Jacquot
- Sorbonne Universités, UPMC Univ Paris 06, Ecole Normale Supérieure,
PSL Research University, CNRS UMR 7203, Laboratoire des Biomolécules, 4, place Jussieu, 75252 Paris Cedex 05, France
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12
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The sequence Pro295-Thr311 of the hinge region of oestrogen receptor α is involved in ERK1/2 activation via GPR30 in leiomyoma cells. Biochem J 2015; 472:97-109. [PMID: 26371374 DOI: 10.1042/bj20150744] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 09/11/2015] [Indexed: 11/17/2022]
Abstract
The ERα (oestrogen receptor α)-derived peptide ERα17p activates rapid signalling events in breast carcinoma cells under steroid-deprived conditions. In the present study, we investigated its effects in ELT3 leiomyoma cells under similar conditions. We show that it activates ERK1/2 (extracellular-signal-regulated kinase 1/2), the Gαi protein, the trans-activation of EGFR (epidermal growth factor receptor) and, finally, cell proliferation. It is partially internalized in cells and induces membrane translocation of β-arrestins. The activation of ERK1/2 is abolished by the GPR30 (G-protein-coupled receptor 30) antagonist G15 and GPR30 siRNA. When ERα is down-regulated by prolonged treatment with E2 (oestradiol) or specific ERα siRNA, the peptide response is blunted. Thus the simultaneous presence of GPR30 and ERα is required for the action of ERα17p. In addition, its PLM sequence, which interferes with the formation of the ERα-calmodulin complex, appears to be requisite for the phosphorylation of ERK1/2 and cell proliferation. Hence ERα17p is, to our knowledge, the first known peptide targeting ERα-GPR30 membrane cross-talk and the subsequent receptor-mediated biological effects.
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13
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Ruggeri FS, Byrne C, Khemtemourian L, Ducouret G, Dietler G, Jacquot Y. Concentration-dependent and surface-assisted self-assembly properties of a bioactive estrogen receptor α-derived peptide. J Pept Sci 2014; 21:95-104. [PMID: 25530026 DOI: 10.1002/psc.2730] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 11/25/2014] [Accepted: 11/28/2014] [Indexed: 11/10/2022]
Abstract
We have synthesized a 17-mer peptide (ERα17p) that is issued from the hinge region of the estrogen receptor α and which activates the proliferation of breast carcinoma cells in steroid-deprived conditions. In the present paper, we show that at a concentration of ~50 μM, it rapidly forms amyloid-like fibrils with the assistance of electrostatic interactions and that at higher concentrations, it spontaneously forms a hydrogel. By using biophysical, spectral and rheological techniques, we have explored the structural, biophysical and mechanical characteristics of ERα17p with respect to fibril formation and gelation.
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Affiliation(s)
- Francesco Simone Ruggeri
- Laboratoire de Physique de la Matière Vivante, Institut de Physique des Systèmes Biologiques, Ecole Polytechnique Fédérale de Lausanne, CH-1015, Lausanne, Switzerland
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14
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Byrne C, Miclet E, Broutin I, Gallo D, Pelekanou V, Kampa M, Castanas E, Leclercq G, Jacquot Y. Identification of polyproline II regions derived from the proline-rich nuclear receptor coactivators PNRC and PNRC2: new insights for ERα coactivator interactions. Chirality 2013; 25:628-42. [PMID: 23925889 DOI: 10.1002/chir.22188] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Accepted: 04/12/2013] [Indexed: 11/07/2022]
Abstract
Protein-protein interactions are crucial for signal transductions required for cell differentiation and proliferation. Their modulation is therefore key to the development of therapeutic alternatives, particularly in the context of cancer. According to literature data, the polyproline-rich nuclear receptor coactivators PNRC and PNRC2 interact with estrogen receptor (ERα) through their PxxP SH3-binding motifs. In a search to identify the molecular features governing this interaction, we explored using electronic circular dichroism (ECD) spectroscopy and molecular dynamics (MD) calculations, the capacity of a range of putative biologically active peptides derived from these proteins and containing this PxxP motif(s) to form polyproline II (PPII) domains. An additional more exhaustive structural study on a lead PPII peptide was also performed using 2D nuclear magnetic resonance (NMR) spectroscopy. With the exception of one of all the investigated peptides (PNRC-D), binding assays failed to detect any affinity for Grb2 SH3 domains, suggesting that PPII motifs issued from Grb2 antagonists have a binding mode distinct from those derived from Grb2 agonists. Instead, the peptides revealed a competitive binding ability against a synthetic peptide (ERα17p) with a putative PPII-cognate domain located within a coregulator recruitment region of ERα (AF-2 site). Our work, which constitutes the first structure-related interaction study concerning PNRC and PNRC2, supports not only the existence of PxxP-induced PPII sequences in these coregulators, but also confirms the presence of a PPII recognition site in the AF-2 of the steroid receptor ERα, a region important for transcription regulation.
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Affiliation(s)
- C Byrne
- Laboratoire des BioMolécules (LBM), CNRS - UMR 7203, Ecole Normale Supérieure / Université Pierre et Marie Curie 24, rue Lhomond, 75231, Paris Cedex 05, France; Fondation Pierre-Gilles de Gennes pour la Recherche, 29, rue d'Ulm, 75005, Paris, France
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15
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Notas G, Kampa M, Pelekanou V, Troullinaki M, Jacquot Y, Leclercq G, Castanas E. Whole transcriptome analysis of the ERα synthetic fragment P295-T311 (ERα17p) identifies specific ERα-isoform (ERα, ERα36)-dependent and -independent actions in breast cancer cells. Mol Oncol 2013; 7:595-610. [PMID: 23474223 DOI: 10.1016/j.molonc.2013.02.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2012] [Revised: 02/06/2013] [Accepted: 02/07/2013] [Indexed: 02/07/2023] Open
Abstract
ERα17p is a peptide corresponding to the sequence P295LMIKRSKKNSLALSLT311 of the estrogen receptor alpha (ERα) and initially found to interfere with ERα-related calmodulin binding. ERα17p was subsequently found to elicit estrogenic responses in E2-deprived ERα-positive breast cancer cells, increasing proliferation and ERE-dependent gene transcription. Surprisingly, in E2-supplemented media, ERα17p-induced apoptosis and modified the actin network, influencing cell motility. Here, we report that ERα17p internalizes in breast cancer cells (T47D, MDA-MB-231, SKBR3) and induces a massive early (3 h) transcriptional activity. Remarkably, about 75% of significantly modified transcripts were also modified by E2, confirming the pro-estrogenic profile of ERα17p. The different ER spectra of the used cell lines allowed us to identify a specific ERα17p signature related to ERα as well as its variant ERα36. With respect to ERα, the peptide activates nuclear (cell cycle, cell proliferation, nucleic acid and protein synthesis) and extranuclear signaling pathways. In contrast, through ERα36, it mainly triggers inhibitory actions on inflammation. This is the first work reporting a detailed ERα36-specific transcriptional signature. In addition, we report that ERα17p-induced transcripts related to apoptosis and actin modifying effects of the peptide are independent from its estrogen receptor(s)-related actions. We discuss our findings in view of the potential use of ERα17p as a selective peptidomimetic estrogen receptor modulator (PERM).
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Affiliation(s)
- George Notas
- Laboratory of Experimental Endocrinology, University of Crete, School of Medicine, P.O. Box 2208, Heraklion 71003, Greece
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16
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Byrne C, Khemtémourian L, Pelekanou V, Kampa M, Leclercq G, Sagan S, Castanas E, Burlina F, Jacquot Y. ERα17p, a peptide reproducing the hinge region of the estrogen receptor α associates to biological membranes: A biophysical approach. Steroids 2012; 77:979-87. [PMID: 22426414 DOI: 10.1016/j.steroids.2012.02.022] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2011] [Revised: 12/22/2011] [Accepted: 02/29/2012] [Indexed: 10/28/2022]
Abstract
Recently, we identified a peptide (ERα17p, P(295)LMIKRSKKNSLALSLT(311)) that corresponds to the 295-311 sequence of the estrogen receptor α (ERα, hinge region) and which exerts a panel of pharmacological effects in breast cancer cells. Remarkably, these effects can result from the interaction of ERα17p with the plasma membrane. Herein, we show that ERα17p adopts a β-sheet secondary structure when in contact with anionic phospholipids and that it is engulfed within the lipid bilayer. While ERα17p increases the fluidity of membrane mimics, it weakly internalizes in living cells. In light of the above, one may evoke one important role of the 295-311 region of the ERα: the corresponding peptide could be secreted/delivered to the extracellular medium to interact with neighboring cells, both intracellularly and at the membrane level. Finally, the 295-311 region of ERα being in proximity to the cystein-447, the palmitoylation site of the ERα raises the question of its involvement in the interaction/stabilization of the protein with the membrane.
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Affiliation(s)
- Cillian Byrne
- Laboratoire des BioMolécules, CNRS-UMR 7203, 24 rue Lhomond, Ecole Normale Supérieure/UPMC Univ Paris 06, 75253 Paris Cedex 05, France
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17
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Kampa M, Pelekanou V, Gallo D, Notas G, Troullinaki M, Pediaditakis I, Charalampopoulos I, Jacquot Y, Leclercq G, Castanas E. ERα17p, an ERα P295 -T311 fragment, modifies the migration of breast cancer cells, through actin cytoskeleton rearrangements. J Cell Biochem 2012; 112:3786-96. [PMID: 21826705 DOI: 10.1002/jcb.23309] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Recently, our knowledge on estrogen receptor alpha (ERα) functions and fate has progressed: ERα enters in repeated transcription-modulating cycles (nucleus/cytoplasm/membrane trafficking processes and proteasomal degradation) that are governed by specific protein-protein interactions. Receptor fragments, especially those resulting from the proteolysis of its ligand binding domain, as well as corresponding synthetic peptides, have been studied with respect to their estrogenic/antiestrogenic potency. A peptide, corresponding to the human ERα P(295) -T(311) sequence (ERα17p) has been shown to alter breast cancer cell fate, triggering proliferation, or apoptosis. The aim of this work was to explore the effect of ERα17p on breast cancer cell migration and actin cytoskeleton dynamics and further analyze the mechanism of its membrane action. We show that ERα17p increases (MCF-7 and SK-BR-3 cells) or decreases (T47D and MDA-MB-231 cells) migration of breast cancer cells, in an ERα-independent manner, by mechanism(s) depending on Rho/ROCK and PI3K/Akt signaling pathways. Moreover, the peptide enhances the association of both estrogens and androgens to membranes and modifies cell migration, induced by E(2) -BSA. Additionally, initial evidence of a possible agonistic action of the peptide on GPR30 is also provided. ERα17p can be considered as a cell migration-modulator and could therefore constitute a therapeutic challenge, even in anti-estrogen-resistant tumors.
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Affiliation(s)
- Marilena Kampa
- Laboratory of Experimental Endocrinology, School of Medicine University of Crete, Heraklion, Greece
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18
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Carlier L, Byrne C, Miclet E, Bourgoin-Voillard S, Nicaise M, Tabet JC, Desmadril M, Leclercq G, Lequin O, Jacquot Y. Biophysical studies of the interaction between calmodulin and the R287-T311 region of human estrogen receptor α reveals an atypical binding process. Biochem Biophys Res Commun 2012; 419:356-61. [DOI: 10.1016/j.bbrc.2012.02.028] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Accepted: 02/03/2012] [Indexed: 10/14/2022]
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19
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The estrogen receptor alpha-derived peptide ERα17p (P(295)-T(311)) exerts pro-apoptotic actions in breast cancer cells in vitro and in vivo, independently from their ERα status. Mol Oncol 2010; 5:36-47. [PMID: 21163714 DOI: 10.1016/j.molonc.2010.11.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2010] [Revised: 11/09/2010] [Accepted: 11/09/2010] [Indexed: 11/22/2022] Open
Abstract
In recent years, our knowledge on estrogen receptors (ER) has been modified profoundly with the identification and the deciphering of the role of its protein effectors, as well as with the deeper insight of its molecular structure/function dynamics, characteristics associated with its nucleo-cytoplasmic-membrane shuttling properties. Also, significant progress has been made concerning its turn-over and associated final proteasomal degradation processes. These advances could lead in the near future to the design and the synthesis of novel receptor-interacting drugs. Recently, a number of receptor-related peptides acting as specific ER ligands have been identified and extensively studied with respect to their estrogenic/antiestrogenic activities. Among them, ERα17p, a synthetic analog of the P(295)-T(311) sequence of ERα, has been shown to exert pseudo-estrogenic effects by interacting in the close vicinity of its hinge region (BF3 domain). Remarkably, this sequence appears as the epicenter of a number of post-transcriptional modifications as well as of the recruitment of co-regulators, suggesting that it would play a key role in ERα functions. Here, we provide evidence that ERα17p induces apoptosis in ERα-positive (MCF-7, T47D) and -negative (MDA-MB-231, SK-BR-3) breast cancer cells by an ERα-independent membrane mechanism, triggering major pro-apoptotic signaling cascades. Finally, ERα17p induces the regression of breast ERα-negative cancer tumor xenografts, without apparent toxicity, suggesting that it could represent a new attractive tool for the development of future promising therapeutic approaches, and providing a novel insight to ER regulation of cell fate.
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20
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Kapitán J, Gallo D, Goasdoué N, Nicaise M, Desmadril M, Hecht L, Leclercq G, Barron LD, Jacquot Y. Identification of a human estrogen receptor α-derived antiestrogenic peptide that adopts a polyproline II conformation. J Pept Sci 2009; 15:455-64. [DOI: 10.1002/psc.1136] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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21
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Mérot Y, Ferrière F, Gailhouste L, Huet G, Percevault F, Saligaut C, Flouriot G. Different outcomes of unliganded and liganded estrogen receptor-alpha on neurite outgrowth in PC12 cells. Endocrinology 2009; 150:200-11. [PMID: 18772239 DOI: 10.1210/en.2008-0449] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
A precise description of the mechanisms by which estrogen receptor-alpha (ERalpha) exerts its influences on cellular growth and differentiation is still pending. Here, we report that the differentiation of PC12 cells is profoundly affected by ERalpha. Importantly, depending upon its binding to 17beta-estradiol (17betaE2), ERalpha is found to exert different effects on pathways involved in nerve growth factor (NGF) signaling. Indeed, upon its stable expression in PC12 cells, unliganded ERalpha is able to partially inhibit the neurite outgrowth induced by NGF. This process involves a repression of MAPK and phosphatidylinositol 3-kinase/Akt signaling pathways, which leads to a negative regulation of markers of neuronal differentiation such as VGF and NFLc. This repressive action of unliganded ERalpha is mediated by its D domain and does not involve its transactivation and DNA-binding domains, thereby suggesting that direct transcriptional activity of ERalpha is not required. In contrast with this repressive action occurring in the absence of 17betaE2, the expression of ERalpha in PC12 cells allows 17betaE2 to potentiate the NGF-induced neurite outgrowth. Importantly, 17betaE2 has no impact on NGF-induced activity of MAPK and Akt signaling pathways. The mechanisms engaged by liganded ERalpha are thus unlikely to rely on an antagonism of the inhibition mediated by the unliganded ERalpha. Furthermore, 17betaE2 enhances NGF-induced response of VGF and NFLc neuronal markers in PC12 clones expressing ERalpha. This stimulatory effect of 17betaE2 requires the transactivation functions of ERalpha and its D domain, suggesting that an estrogen-responsive element-independent transcriptional mechanism is potentially relevant for the neuritogenic properties of 17betaE2 in ERalpha-expressing PC12 cells.
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Affiliation(s)
- Yohann Mérot
- Université de Rennes 1, Centre National de la Recherche Scientifique, Unité Mixte 6026, Equipe Récepteur des oestrogènes et destinée cellulaire, 35042 Rennes, France
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22
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Gallo D, Jacquot Y, Laurent G, Leclercq G. Calmodulin, a regulatory partner of the estrogen receptor alpha in breast cancer cells. Mol Cell Endocrinol 2008; 291:20-6. [PMID: 18524472 DOI: 10.1016/j.mce.2008.04.011] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2008] [Revised: 04/14/2008] [Accepted: 04/15/2008] [Indexed: 02/07/2023]
Abstract
Although calmodulin (CaM) interaction with estrogen receptor alpha (ERalpha) has been known for more than two decades, it is only recently that the molecular mechanism of CaM-mediated regulation of ERalpha is beginning to emerge. Others and we have identified a putative calmodulin binding site (P(295)LMIKRSKKNSLALSTADQMVS(317)) in ERalpha, at the boundary between the hinge and the ligand binding domain. ERalpha mutations affecting its association with CaM have been reported to generate high basal, estrogen-independent transactivation activity, indicating that the P(295)-T(317) sequence has an inhibitory function. Moreover, we found that a synthetic peptide (ERalpha17p: P(295)-T(311)) containing residues crucial for CaM binding exerts estrogenic effects on breast carcinoma cells. Finally, computer-aided conformational studies revealed that the CaM binding site might associate with a region located downstream in ERalpha (the beta turn/H4 region), this association likely resulting in an auto-inhibitory folding of the receptor. Thus, we propose as a hypothesis that CaM acts as a positive regulator by relieving this ERalpha auto-inhibition.
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Affiliation(s)
- Dominique Gallo
- Laboratoire J.-C. Heuson de Cancérologie Mammaire, Université Libre de Bruxelles, Institut Jules Bordet, 1 rue Héger-Bordet, B-1000 Brussels, Belgium
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23
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Gallo D, Haddad I, Laurent G, Vinh J, Jacquemotte F, Jacquot Y, Leclercq G. Regulatory function of the P295-T311 motif of the estrogen receptor alpha - does proteasomal degradation of the receptor induce emergence of peptides implicated in estrogenic responses? NUCLEAR RECEPTOR SIGNALING 2008; 6:e007. [PMID: 18432312 PMCID: PMC2329824 DOI: 10.1621/nrs.06007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2007] [Accepted: 04/01/2008] [Indexed: 11/29/2022]
Abstract
The way in which estrogen receptor α (ERα) mediates gene transcription and hormone-dependent cancer cell proliferation is now being largely reconsidered in view of several recent discoveries. ERα-mediated transcription appears to be a cyclic and transient process where the proteasome - and thus receptor degradation - plays a pivotal role. In view of our recent investigations, which demonstrate the estrogenic activity of a synthetic peptide corresponding to a regulatory motif of the receptor (ERα17p), we propose that ERα proteasomal degradation could induce the emergence of regulatory peptide(s). The latter would function as a signal and contribute to the ERα activation process, amplifying the initial hormonal stimulation and giving rise to sustained estrogenic response.
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Affiliation(s)
- Dominique Gallo
- Laboratoire J.-C. Heuson de Cancérologie Mammaire, Université Libre de Bruxelles (ULB), Institut Jules Bordet, Brussels, Belgium
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