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Overview of Sigma-1R Subcellular Specific Biological Functions and Role in Neuroprotection. Int J Mol Sci 2023; 24:ijms24031971. [PMID: 36768299 PMCID: PMC9916267 DOI: 10.3390/ijms24031971] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 01/15/2023] [Accepted: 01/17/2023] [Indexed: 01/20/2023] Open
Abstract
For the past several years, fundamental research on Sigma-1R (S1R) protein has unveiled its necessity for maintaining proper cellular homeostasis through modulation of calcium and lipid exchange between the endoplasmic reticulum (ER) and mitochondria, ER-stress response, and many other mechanisms. Most of these processes, such as ER-stress response and autophagy, have been associated with neuroprotective roles. In fact, improving these mechanisms using S1R agonists was beneficial in several brain disorders including neurodegenerative diseases. In this review, we will examine S1R subcellular localization and describe S1R-associated biological activity within these specific compartments, i.e., the Mitochondrion-Associated ER Membrane (MAM), ER-Lipid Droplet (ER-LD) interface, ER-Plasma Membreane (ER-PM) interface, and the Nuclear Envelope (NE). We also discussed how the dysregulation of these pathways contributes to neurodegenerative diseases, while highlighting the cellular mechanisms and key binding partners engaged in these processes.
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Fallica AN, Ciaffaglione V, Modica MN, Pittalà V, Salerno L, Amata E, Marrazzo A, Romeo G, Intagliata S. Structure-activity relationships of mixed σ1R/σ2R ligands with antiproliferative and anticancer effects. Bioorg Med Chem 2022; 73:117032. [DOI: 10.1016/j.bmc.2022.117032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 09/16/2022] [Accepted: 09/21/2022] [Indexed: 11/27/2022]
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3
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Brown JS. Treatment of cancer with antipsychotic medications: Pushing the boundaries of schizophrenia and cancer. Neurosci Biobehav Rev 2022; 141:104809. [PMID: 35970416 DOI: 10.1016/j.neubiorev.2022.104809] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Revised: 07/30/2022] [Accepted: 07/31/2022] [Indexed: 10/15/2022]
Abstract
Over a century ago, the phenothiazine dye, methylene blue, was discovered to have both antipsychotic and anti-cancer effects. In the 20th-century, the first phenothiazine antipsychotic, chlorpromazine, was found to inhibit cancer. During the years of elucidating the pharmacology of the phenothiazines, reserpine, an antipsychotic with a long historical background, was likewise discovered to have anti-cancer properties. Research on the effects of antipsychotics on cancer continued slowly until the 21st century when efforts to repurpose antipsychotics for cancer treatment accelerated. This review examines the history of these developments, and identifies which antipsychotics might treat cancer, and which cancers might be treated by antipsychotics. The review also describes the molecular mechanisms through which antipsychotics may inhibit cancer. Although the overlap of molecular pathways between schizophrenia and cancer have been known or suspected for many years, no comprehensive review of the subject has appeared in the psychiatric literature to assess the significance of these similarities. This review fills that gap and discusses what, if any, significance the similarities have regarding the etiology of schizophrenia.
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Haloperidol Instigates Endometrial Carcinogenesis and Cancer Progression by the NF-κB/CSF-1 Signaling Cascade. Cancers (Basel) 2022; 14:cancers14133089. [PMID: 35804859 PMCID: PMC9265032 DOI: 10.3390/cancers14133089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 06/18/2022] [Accepted: 06/20/2022] [Indexed: 11/16/2022] Open
Abstract
Simple Summary Haloperidol, a typical antipsychotic, is widely used in schizophrenia and palliative care of cancer; however, the role and impact of chronic haloperidol treatment in endometrial cancer (EC) development are unclear. Here, we showed that haloperidol is a carcinogenic compound capable of inducing endometrial hyperplasia and promoting EC progression in rodents. Mechanistically, haloperidol stimulates the production of colony-stimulating factor 1 (CSF-1) on tumor cells by activating nuclear factor kappa B (NF-κB), and its downstream autocrine oncogenic CSF-1 receptor signaling contributes to this carcinogenesis. Furthermore, we demonstrated that the use of haloperidol is associated with increased EC-specific mortality in EC patients. Overall, these findings highlighted that physicians should be cautious about the use of haloperidol in female patients. Abstract Haloperidol is a routine drug for schizophrenia and palliative care of cancer; it also has antitumor effects in several types of cancer. However, the role of haloperidol in endometrial cancer (EC) development is still unclear. Here, we show that chronic haloperidol treatment in clinically relevant doses induced endometrial hyperplasia in normal mice and promoted tumor growth and malignancy in mice with orthotopic EC. The pharmacokinetic study indicated that haloperidol highly accumulated in the uterus of mice. In vitro studies revealed that haloperidol stimulated the cellular transformation of human endometrial epithelial cells (HECCs) and promoted the proliferation, migration, and invasion of human endometrial carcinoma cells (HECCs) by activating nuclear factor kappa B (NF-κB) and its downstream signaling target, colony-stimulating factor 1 (CSF-1). Gain of function of CSF-1 promotes the cellular transformation of HEECs and the malignant progression of HECCs. Moreover, blockade of CSF-1 inhibited haloperidol-promoted EC progression in vitro and in vivo. A population-based cohort study of EC patients further demonstrated that the use of haloperidol was associated with increased EC-specific mortality. Collectively, these findings indicate that clinical use of haloperidol could potentially be harmful to female patients with EC.
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5
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Abatematteo FS, Niso M, Lacivita E, Abate C. σ 2 Receptor and Its Role in Cancer with Focus on a MultiTarget Directed Ligand (MTDL) Approach. Molecules 2021; 26:3743. [PMID: 34205334 PMCID: PMC8235595 DOI: 10.3390/molecules26123743] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 06/14/2021] [Accepted: 06/15/2021] [Indexed: 11/19/2022] Open
Abstract
Sigma-2 (σ2) is an endoplasmic receptor identified as the Endoplasmic Reticulum (ER) transmembrane protein TMEM97. Despite its controversial identity, which was only recently solved, this protein has gained scientific interest because of its role in the proliferative status of cells; many tumor cells from different organs overexpress the σ2 receptor, and many σ2 ligands display cytotoxic actions in (resistant) cancer cells. These properties have shed light on the σ2 receptor as a potential druggable target to be bound/activated for the diagnosis or therapy of tumors. Additionally, diverse groups have shown how the σ2 receptor can be exploited for the targeted delivery of the anticancer drugs to tumors. As the cancer disease is a multifactorial pathology with multiple cell populations, a polypharmacological approach is very often needed. Instead of the simultaneous administration of different classes of drugs, the use of one molecule that interacts with diverse pharmacological targets, namely MultiTarget Directed Ligand (MTDL), is a promising and currently pursued strategy, that may overcome the pharmacokinetic problems associated with the administration of multiple molecules. This review aims to point out the progress regarding the σ2 ligands in the oncology field, with a focus on MTDLs directed towards σ2 receptors as promising weapons against (resistant) cancer diseases.
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Affiliation(s)
| | | | | | - Carmen Abate
- Dipartimento di Farmacia-Scienze del Farmaco, Università degli Studi di Bari ALDO MORO, Via Orabona 4, 70125 Bari, Italy; (F.S.A.); (M.N.); (E.L.)
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6
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Abatematteo FS, Niso M, Contino M, Leopoldo M, Abate C. Multi-Target Directed Ligands (MTDLs) Binding the σ 1 Receptor as Promising Therapeutics: State of the Art and Perspectives. Int J Mol Sci 2021; 22:6359. [PMID: 34198620 PMCID: PMC8232171 DOI: 10.3390/ijms22126359] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 05/31/2021] [Accepted: 06/10/2021] [Indexed: 11/18/2022] Open
Abstract
The sigma-1 (σ1) receptor is a 'pluripotent chaperone' protein mainly expressed at the mitochondria-endoplasmic reticulum membrane interfaces where it interacts with several client proteins. This feature renders the σ1 receptor an ideal target for the development of multifunctional ligands, whose benefits are now recognized because several pathologies are multifactorial. Indeed, the current therapeutic regimens are based on the administration of different classes of drugs in order to counteract the diverse unbalanced physiological pathways associated with the pathology. Thus, the multi-targeted directed ligand (MTDL) approach, with one molecule that exerts poly-pharmacological actions, may be a winning strategy that overcomes the pharmacokinetic issues linked to the administration of diverse drugs. This review aims to point out the progress in the development of MTDLs directed toward σ1 receptors for the treatment of central nervous system (CNS) and cancer diseases, with a focus on the perspectives that are proper for this strategy. The evidence that some drugs in clinical use unintentionally bind the σ1 protein (as off-target) provides a proof of concept of the potential of this strategy, and it strongly supports the promise that the σ1 receptor holds as a target to be hit in the context of MTDLs for the therapy of multifactorial pathologies.
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Affiliation(s)
| | | | | | | | - Carmen Abate
- Dipartimento di Farmacia-Scienze del Farmaco, Università degli Studi di Bari ALDO MORO, Via Orabona 4, 70125 Bari, Italy; (F.S.A.); (M.N.); (M.C.); (M.L.)
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7
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Design, synthesis and antiproliferative activity of new amine, amino acid and dipeptide-coupled benzamides as potential sigma-1 receptor. JOURNAL OF THE IRANIAN CHEMICAL SOCIETY 2020. [DOI: 10.1007/s13738-020-01947-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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8
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Toussaint M, Deuther-Conrad W, Kranz M, Fischer S, Ludwig FA, Juratli TA, Patt M, Wünsch B, Schackert G, Sabri O, Brust P. Sigma-1 Receptor Positron Emission Tomography: A New Molecular Imaging Approach Using ( S)-(-)-[ 18F]Fluspidine in Glioblastoma. Molecules 2020; 25:E2170. [PMID: 32384802 PMCID: PMC7248975 DOI: 10.3390/molecules25092170] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 04/30/2020] [Accepted: 05/02/2020] [Indexed: 11/16/2022] Open
Abstract
Glioblastoma multiforme (GBM) is the most devastating primary brain tumour characterised by infiltrative growth and resistance to therapies. According to recent research, the sigma-1 receptor (sig1R), an endoplasmic reticulum chaperone protein, is involved in signaling pathways assumed to control the proliferation of cancer cells and thus could serve as candidate for molecular characterisation of GBM. To test this hypothesis, we used the clinically applied sig1R-ligand (S)-(-)-[18F]fluspidine in imaging studies in an orthotopic mouse model of GBM (U87-MG) as well as in human GBM tissue. A tumour-specific overexpression of sig1R in the U87-MG model was revealed in vitro by autoradiography. The binding parameters demonstrated target-selective binding according to identical KD values in the tumour area and the contralateral side, but a higher density of sig1R in the tumour. Different kinetic profiles were observed in both areas, with a slower washout in the tumour tissue compared to the contralateral side. The translational relevance of sig1R imaging in oncology is reflected by the autoradiographic detection of tumour-specific expression of sig1R in samples obtained from patients with glioblastoma. Thus, the herein presented data support further research on sig1R in neuro-oncology.
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Affiliation(s)
- Magali Toussaint
- Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institute of Radiopharmaceutical Cancer Research, Department of Neuroradiopharmaceuticals, Research site Leipzig, 04318 Leipzig, Germany; (W.D.-C.); (M.K.); (S.F.); (F.-A.L.); (P.B.)
| | - Winnie Deuther-Conrad
- Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institute of Radiopharmaceutical Cancer Research, Department of Neuroradiopharmaceuticals, Research site Leipzig, 04318 Leipzig, Germany; (W.D.-C.); (M.K.); (S.F.); (F.-A.L.); (P.B.)
| | - Mathias Kranz
- Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institute of Radiopharmaceutical Cancer Research, Department of Neuroradiopharmaceuticals, Research site Leipzig, 04318 Leipzig, Germany; (W.D.-C.); (M.K.); (S.F.); (F.-A.L.); (P.B.)
- PET Imaging Center, University Hospital of North Norway (UNN), 9009 Tromsø, Norway
- Nuclear Medicine and Radiation Biology Research Group, The Arctic University of Norway, 9009 Tromsø, Norway
| | - Steffen Fischer
- Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institute of Radiopharmaceutical Cancer Research, Department of Neuroradiopharmaceuticals, Research site Leipzig, 04318 Leipzig, Germany; (W.D.-C.); (M.K.); (S.F.); (F.-A.L.); (P.B.)
| | - Friedrich-Alexander Ludwig
- Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institute of Radiopharmaceutical Cancer Research, Department of Neuroradiopharmaceuticals, Research site Leipzig, 04318 Leipzig, Germany; (W.D.-C.); (M.K.); (S.F.); (F.-A.L.); (P.B.)
| | - Tareq A. Juratli
- Department of Neurosurgery, Technische Universität Dresden (TUD), University Hospital Carl Gustav Carus, 01307 Dresden, Germany; (T.A.J.); (G.S.)
| | - Marianne Patt
- Department of Nuclear Medicine, University Hospital Leipzig, 04318 Leipzig, Germany; (M.P.); (O.S.)
| | - Bernhard Wünsch
- Institute of Pharmaceutical and Medicinal Chemistry, University of Münster, 48149 Münster, Germany;
| | - Gabriele Schackert
- Department of Neurosurgery, Technische Universität Dresden (TUD), University Hospital Carl Gustav Carus, 01307 Dresden, Germany; (T.A.J.); (G.S.)
| | - Osama Sabri
- Department of Nuclear Medicine, University Hospital Leipzig, 04318 Leipzig, Germany; (M.P.); (O.S.)
| | - Peter Brust
- Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institute of Radiopharmaceutical Cancer Research, Department of Neuroradiopharmaceuticals, Research site Leipzig, 04318 Leipzig, Germany; (W.D.-C.); (M.K.); (S.F.); (F.-A.L.); (P.B.)
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9
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Synthesis and evaluation of haloperidol metabolite II prodrugs as anticancer agents. Future Med Chem 2017; 9:1749-1764. [DOI: 10.4155/fmc-2017-0064] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The use of haloperidol metabolite II (HP-metabolite II) prodrugs is an emerging strategy in the treatment of cancer. HP-metabolite II exhibits antiproliferative properties at micromolar concentrations inducing apoptosis in different types of cancer. Thus, the application of the prodrug approach appears as a useful method leading to much more desirable pharmacokinetic and pharmacodynamic properties. Some studies have shown that the esterification of the hydroxyl group of HP-metabolite II with 4-phenylbutiric acid (4-PBA) or valproic acid enhances the anticancer therapeutic potency. The current progresses in the design, synthesis and evaluation of anticancer activity of HP metabolite II prodrugs will be discussed in this review.
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10
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Potential independent action of sigma receptor ligands through inhibition of the Kv2.1 channel. Oncotarget 2017; 8:59345-59358. [PMID: 28938641 PMCID: PMC5601737 DOI: 10.18632/oncotarget.19581] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Accepted: 06/16/2017] [Indexed: 12/14/2022] Open
Abstract
The sigma-1 receptor (σ1-R) and sigma-2 receptor (σ2-R) are potential drug targets for treatment of cancer, pain, depression, retinal degeneration and other neuronal diseases. Previous reports show that sigma-1 receptor modulates the activities of multiple channels. We are interested in possible sigma receptor modulation of Kv2.1, a K+ channel abundant in retinal photoreceptors. We tested the effect of established sigma receptor ligands on Kv2.1 channels which were stably expressed in HEK293 cells. Surprisingly, σ1-R antagonists inhibited Kv2.1 currents in both wild type and σ1-R knockout HEK293 cells that we engineered using the CRISPR/Cas9 technology. Moreover, PB28, a σ1-R antagonist and also σ2-R agonist, inhibited Kv2.1 in σ1-R knockout cells, but this action was not blocked by the σ2-R antagonists that did not have an effect on Kv2.1. We also observed inhibition of electroretinogram by PB28 in wild type as well as σ1-R knockout mice. Thus, the results in this study indicate that the Kv2.1-inhibiting function of the sigma ligands is not sigma receptor dependent, suggesting a direct effect of these ligands on the Kv2.1 channel.
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11
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Yi B, Sahn JJ, Ardestani PM, Evans AK, Scott LL, Chan JZ, Iyer S, Crisp A, Zuniga G, Pierce JT, Martin SF, Shamloo M. Small molecule modulator of sigma 2 receptor is neuroprotective and reduces cognitive deficits and neuroinflammation in experimental models of Alzheimer's disease. J Neurochem 2017; 140:561-575. [PMID: 27926996 DOI: 10.1111/jnc.13917] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 11/23/2016] [Accepted: 12/01/2016] [Indexed: 12/29/2022]
Abstract
Accumulating evidence suggests that modulating the sigma 2 receptor (Sig2R) can provide beneficial effects for neurodegenerative diseases. Herein, we report the identification of a novel class of Sig2R ligands and their cellular and in vivo activity in experimental models of Alzheimer's disease (AD). We report that SAS-0132 and DKR-1051, selective ligands of Sig2R, modulate intracellular Ca2+ levels in human SK-N-SH neuroblastoma cells. The Sig2R ligands SAS-0132 and JVW-1009 are neuroprotective in a C. elegans model of amyloid precursor protein-mediated neurodegeneration. Since this neuroprotective effect is replicated by genetic knockdown and knockout of vem-1, the ortholog of progesterone receptor membrane component-1 (PGRMC1), these results suggest that Sig2R ligands modulate a PGRMC1-related pathway. Last, we demonstrate that SAS-0132 improves cognitive performance both in the Thy-1 hAPPLond/Swe+ transgenic mouse model of AD and in healthy wild-type mice. These results demonstrate that Sig2R is a promising therapeutic target for neurocognitive disorders including AD.
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Affiliation(s)
- Bitna Yi
- Department of Neurosurgery, Stanford University School of Medicine, Palo Alto, California, USA
| | - James J Sahn
- Department of Chemistry, The University of Texas at Austin, Austin, Texas, USA
| | - Pooneh Memar Ardestani
- Department of Neurosurgery, Stanford University School of Medicine, Palo Alto, California, USA
| | - Andrew K Evans
- Department of Neurosurgery, Stanford University School of Medicine, Palo Alto, California, USA
| | - Luisa L Scott
- Waggoner Center for Alcohol and Addiction Research, Institute of Neuroscience, Center for Learning and Memory, Center for Brain, Behavior and Evolution and Department of Neuroscience, The University of Texas at Austin, Austin, Texas, USA
| | - Jessica Z Chan
- Department of Chemistry, The University of Texas at Austin, Austin, Texas, USA
| | - Sangeetha Iyer
- Waggoner Center for Alcohol and Addiction Research, Institute of Neuroscience, Center for Learning and Memory, Center for Brain, Behavior and Evolution and Department of Neuroscience, The University of Texas at Austin, Austin, Texas, USA
| | - Ashley Crisp
- Waggoner Center for Alcohol and Addiction Research, Institute of Neuroscience, Center for Learning and Memory, Center for Brain, Behavior and Evolution and Department of Neuroscience, The University of Texas at Austin, Austin, Texas, USA
| | - Gabriella Zuniga
- Waggoner Center for Alcohol and Addiction Research, Institute of Neuroscience, Center for Learning and Memory, Center for Brain, Behavior and Evolution and Department of Neuroscience, The University of Texas at Austin, Austin, Texas, USA
| | - Jonathan T Pierce
- Waggoner Center for Alcohol and Addiction Research, Institute of Neuroscience, Center for Learning and Memory, Center for Brain, Behavior and Evolution and Department of Neuroscience, The University of Texas at Austin, Austin, Texas, USA
| | - Stephen F Martin
- Department of Chemistry, The University of Texas at Austin, Austin, Texas, USA
| | - Mehrdad Shamloo
- Department of Neurosurgery, Stanford University School of Medicine, Palo Alto, California, USA
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12
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Abstract
Sigma1 (also known as sigma-1 receptor, Sig1R, σ1 receptor) is a unique pharmacologically regulated integral membrane chaperone or scaffolding protein. The majority of publications on the subject have focused on the neuropharmacology of Sigma1. However, a number of publications have also suggested a role for Sigma1 in cancer. Although there is currently no clinically used anti-cancer drug that targets Sigma1, a growing body of evidence supports the potential of Sigma1 ligands as therapeutic agents to treat cancer. In preclinical models, compounds with affinity for Sigma1 have been reported to inhibit cancer cell proliferation and survival, cell adhesion and migration, tumor growth, to alleviate cancer-associated pain, and to have immunomodulatory properties. This review will highlight that although the literature supports a role for Sigma1 in cancer, several fundamental questions regarding drug mechanism of action and the physiological relevance of aberrant SIGMAR1 transcript and Sigma1 protein expression in certain cancers remain unanswered or only partially answered. However, emerging lines of evidence suggest that Sigma1 is a component of the cancer cell support machinery, that it facilitates protein interaction networks, that it allosterically modulates the activity of its associated proteins, and that Sigma1 is a selectively multifunctional drug target.
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Affiliation(s)
- Felix J Kim
- Department of Pharmacology and Physiology, Drexel University College of Medicine, 245 North 15th Street, Philadelphia, PA, USA.
- Sidney Kimmel Cancer Center, Philadelphia, PA, USA.
| | - Christina M Maher
- Department of Pharmacology and Physiology, Drexel University College of Medicine, 245 North 15th Street, Philadelphia, PA, USA
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13
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Abstract
This review compares the biological and physiological function of Sigma receptors [σRs] and their potential therapeutic roles. Sigma receptors are widespread in the central nervous system and across multiple peripheral tissues. σRs consist of sigma receptor one (σ1R) and sigma receptor two (σ2R) and are expressed in numerous regions of the brain. The sigma receptor was originally proposed as a subtype of opioid receptors and was suggested to contribute to the delusions and psychoses induced by benzomorphans such as SKF-10047 and pentazocine. Later studies confirmed that σRs are non-opioid receptors (not an µ opioid receptor) and play a more diverse role in intracellular signaling, apoptosis and metabolic regulation. σ1Rs are intracellular receptors acting as chaperone proteins that modulate Ca2+ signaling through the IP3 receptor. They dynamically translocate inside cells, hence are transmembrane proteins. The σ1R receptor, at the mitochondrial-associated endoplasmic reticulum membrane, is responsible for mitochondrial metabolic regulation and promotes mitochondrial energy depletion and apoptosis. Studies have demonstrated that they play a role as a modulator of ion channels (K+ channels; N-methyl-d-aspartate receptors [NMDAR]; inositol 1,3,5 triphosphate receptors) and regulate lipid transport and metabolism, neuritogenesis, cellular differentiation and myelination in the brain. σ1R modulation of Ca2+ release, modulation of cardiac myocyte contractility and may have links to G-proteins. It has been proposed that σ1Rs are intracellular signal transduction amplifiers. This review of the literature examines the mechanism of action of the σRs, their interaction with neurotransmitters, pharmacology, location and adverse effects mediated through them.
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Affiliation(s)
- Colin G Rousseaux
- a Department of Pathology and Laboratory Medicine , University of Ottawa , Ottawa , ON , Canada and
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14
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Zhu J, Qian W, Wang Y, Gao R, Wang J, Xiao H. Involvement of mitogen-activated protein kinase and NF-κB signaling pathways in perfluorooctane sulfonic acid-induced inflammatory reaction in BV2 microglial cells. J Appl Toxicol 2015; 35:1539-49. [DOI: 10.1002/jat.3119] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Revised: 12/15/2014] [Accepted: 12/15/2014] [Indexed: 11/11/2022]
Affiliation(s)
- Jingying Zhu
- Key Lab of Modern Toxicology (NJMU), Ministry of Education, Department of Toxicology, School of Public Health; Nanjing Medical University; Nanjing Jiangsu China
| | - Wenyi Qian
- Key Lab of Modern Toxicology (NJMU), Ministry of Education, Department of Toxicology, School of Public Health; Nanjing Medical University; Nanjing Jiangsu China
| | - Yixin Wang
- Key Lab of Modern Toxicology (NJMU), Ministry of Education, Department of Toxicology, School of Public Health; Nanjing Medical University; Nanjing Jiangsu China
| | - Rong Gao
- Key Lab of Modern Toxicology (NJMU), Ministry of Education, Department of Toxicology, School of Public Health; Nanjing Medical University; Nanjing Jiangsu China
| | - Jun Wang
- Key Lab of Modern Toxicology (NJMU), Ministry of Education, Department of Toxicology, School of Public Health; Nanjing Medical University; Nanjing Jiangsu China
| | - Hang Xiao
- Key Lab of Modern Toxicology (NJMU), Ministry of Education, Department of Toxicology, School of Public Health; Nanjing Medical University; Nanjing Jiangsu China
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15
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Schrock JM, Spino CM, Longen CG, Stabler SM, Marino JC, Pasternak GW, Kim FJ. Sequential cytoprotective responses to Sigma1 ligand-induced endoplasmic reticulum stress. Mol Pharmacol 2013; 84:751-62. [PMID: 24006496 DOI: 10.1124/mol.113.087809] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The Sigma1 receptor (Sigma1) is an endoplasmic reticulum (ER) integral membrane protein that is highly expressed in a number of cancer cell lines. Small molecule compounds targeting Sigma1 (Sigma1 ligands) inhibit cancer cell proliferation and induce apoptotic cell death in vitro and inhibit tumor growth in xenograft experiments. However, the cellular pathways activated by Sigma1 protein-ligand interaction are not well defined. Here, we find that treatment with some Sigma1 ligands induces ER stress and activates the unfolded protein response (UPR) in a dose- and time-responsive manner in a range of adenocarcinoma cell lines. Autophagy is engaged after extended treatment with Sigma1 ligands, which suggests that protracted UPR results in autophagy as a secondary response. Inhibition of UPR by RNAi-mediated knockdown of inositol-requiring enzyme 1α and activating transcription factor 4 abrogates autophagosome formation, as does knockdown of essential autophagy gene products Beclin1 and autophagy protein 5. Knockdown of Sigma1 also suppresses IPAG [1-(4-iodophenyl)-3-(2-adamantyl) guanidine] induced UPR marker and autophagosome levels, indicating that this response is indeed Sigma1-mediated. We find that UPR activation precedes autophagosome formation and autophagy precedes apoptosis in Sigma1 ligand-treated cells. These processes are reversible, and washout of IPAG before cell death results in a return of autophagosomes and UPR markers toward basal levels. However, inhibition of Sigma1 ligand-induced UPR or autophagy accelerates apoptotic cell death. Together, these data suggest that UPR and autophagy are engaged as primary and secondary cytoprotective responses, respectively, to Sigma1 ligand-induced disruption of cancer cell protein homeostasis.
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Affiliation(s)
- Joel M Schrock
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania (C.M.S., C.G.L., F.J.K.); and Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, New York, New York (J.M.S., S.M.S., J.C.M., G.W.P.)
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Rybczynska AA, de Bruyn M, Ramakrishnan NK, de Jong JR, Elsinga PH, Helfrich W, Dierckx RA, van Waarde A. In Vivo Responses of Human A375M Melanoma to a σ Ligand: 18F-FDG PET Imaging. J Nucl Med 2013; 54:1613-20. [DOI: 10.2967/jnumed.113.122655] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Huang YS, Lu HL, Zhang LJ, Wu Z. Sigma-2 receptor ligands and their perspectives in cancer diagnosis and therapy. Med Res Rev 2013; 34:532-66. [PMID: 23922215 DOI: 10.1002/med.21297] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The sigma-2 receptor is highly expressed in various rapidly proliferating cancer cells and regarded as a cancer cell biomarker. Selective sigma-2 ligands have been shown to specifically label the tumor sites, induce cancer cells to undergo apoptosis, and inhibit tumor growth. Sigma-2 ligands are potentially useful as cancer diagnostics, anticancer therapeutics, or adjuvant anticancer treatment agents. However, both the cloning of this receptor and the identification of its endogenous ligand have not been successful, and the lack of structural information has severely hindered the understanding of its physiological roles, its signaling pathways, and the development of more selective sigma-2 ligands. Recent data have implicated that sigma-2 binding sites are within the lipid rafts and that PGRMC1 (progesterone receptor membrane component 1) complex and sigma-2 receptor may be coupled with EGFR (epidermal growth factor receptor), mTOR (mammalian target of rapamycin), caspases, and ion channels. Due to its promising applications in cancer management, there are rapidly increasing research efforts that are being directed into this field. This review article updates the current understanding of sigma-2 receptor and its potential physiological roles, applications, interaction with other effectors, with special focuses on the development of sigma-2 ligands, their chemical structures, pharmacological profiles, applications in imaging and anticancer therapy.
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Affiliation(s)
- Yun-Sheng Huang
- School of Pharmacy, Guangdong Medical College, 1 Xincheng Ave, Songshan Lake Technology Park, Dongguan, Guangdong, 523808, China
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Kim FJ, Schrock JM, Spino CM, Marino JC, Pasternak GW. Inhibition of tumor cell growth by Sigma1 ligand mediated translational repression. Biochem Biophys Res Commun 2012; 426:177-82. [PMID: 22925888 PMCID: PMC3480203 DOI: 10.1016/j.bbrc.2012.08.052] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2012] [Accepted: 08/13/2012] [Indexed: 01/08/2023]
Abstract
Treatment with sigma1 receptor (Sigma1) ligands can inhibit cell proliferation in vitro and tumor growth in vivo. However, the cellular pathways engaged in response to Sigma1 ligand treatment that contribute to these outcomes remain largely undefined. Here, we show that treatment with putative antagonists of Sigma1 decreases cell mass. This effect corresponds with repressed cap-dependent translation initiation in multiple breast and prostate cancer cell lines. Sigma1 antagonist treatment suppresses phosphorylation of translational regulator proteins p70S6K, S6, and 4E-BP1. RNAi-mediated knockdown of Sigma1 also results in translational repression, consistent with the effects of antagonist treatment. Sigma1 antagonist mediated translational repression and decreased cell size are both reversible. Together, these data reveal a role for Sigma1 in tumor cell protein synthesis, and demonstrate that small molecule Sigma1 ligands can be used as modulators of protein translation.
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Affiliation(s)
- Felix J Kim
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA 19102-1192, USA.
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Abstract
BACKGROUND The sigma-2 receptor has been identified as a biomarker of proliferating cells in solid tumours. In the present study, we studied the mechanisms of sigma-2 ligand-induced cell death in the mouse breast cancer cell line EMT-6 and the human melanoma cell line MDA-MB-435. METHODS EMT-6 and MDA-MB-435 cells were treated with sigma-2 ligands. The modulation of multiple signaling pathways of cell death was evaluated. RESULTS Three sigma-2 ligands (WC-26, SV119 and RHM-138) induced DNA fragmentation, caspase-3 activation and PARP-1 cleavage. The caspase inhibitor Z-VAD-FMK partially blocked DNA fragmentation and cytotoxicity caused by these compounds. These data suggest that sigma-2 ligand-induced apoptosis and caspase activation are partially responsible for the cell death. WC-26 and siramesine induced formation of vacuoles in the cells. WC-26, SV119, RHM-138 and siramesine increased the synthesis and processing of microtubule-associated protein light chain 3, an autophagosome marker, and decreased the expression levels of the downstream effectors of mammalian target of rapamycin (mTOR), p70S6K and 4EBP1, suggesting that sigma-2 ligands induce autophagy, probably by inhibition of the mTOR pathway. All four sigma-2 ligands decreased the expression of cyclin D1 in a time-dependent manner. In addition, WC-26 and SV119 mainly decreased cyclin B1, E2 and phosphorylation of retinoblastoma protein (pRb); RHM-138 mainly decreased cyclin E2; and 10 μM siramesine mainly decreased cyclin B1 and pRb. These data suggest that sigma-2 ligands also impair cell-cycle progression in multiple phases of the cell cycle. CONCLUSION Sigma-2 ligands induce cell death by multiple signalling pathways.
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Brimson JM, Brown CA, Safrany ST. Antagonists show GTP-sensitive high-affinity binding to the sigma-1 receptor. Br J Pharmacol 2011; 164:772-80. [PMID: 21486275 PMCID: PMC3188898 DOI: 10.1111/j.1476-5381.2011.01417.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2010] [Revised: 01/06/2011] [Accepted: 03/29/2011] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND AND PURPOSE Sigma-1 receptors are atypical receptors with potentially two transmembrane domains. Antagonists require doses significantly higher than their published affinities to have biological effects. We have reassessed the binding characteristics of these ligands and found antagonists bind to high- and low-affinity states not distinguished by agonists. EXPERIMENTAL APPROACH The affinities of sigma-1 receptor ligands was assessed using radioligand saturation and competition binding of [³H]-(+)-pentazocine to permeabilized MDA-MB-468 cells. This was compared with the effect of ligands on metabolic activity using an MTS-based assay and calcium signalling using cells loaded with the calcium dye, Fura-2. KEY RESULTS Sigma-1 receptor antagonists, but not agonists, show GTP- and suramin-sensitive high-affinity binding. Functional responses (calcium signalling and metabolic activity), while associated with sigma-1 receptor binding, required binding to an unidentified, low-affinity target. CONCLUSIONS AND IMPLICATIONS Sigma-1 receptors are coupled to G proteins. This interaction is only observed when analysing antagonist binding. The identity of the G protein remains to be resolved. The concept of agonist and antagonist at the sigma-1 receptor needs to be revisited.
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Affiliation(s)
- JM Brimson
- Department of Pharmacy and Pharmacology, University of BathBath, UK
| | - CA Brown
- Department of Pharmacy, University of WolverhamptonWolverhampton, UK
| | - ST Safrany
- Department of Pharmacy and Pharmacology, University of BathBath, UK
- Department of Pharmacy, University of WolverhamptonWolverhampton, UK
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Pal K, Pore S, Sinha S, Janardhanan R, Mukhopadhyay D, Banerjee R. Structure-activity study to develop cationic lipid-conjugated haloperidol derivatives as a new class of anticancer therapeutics. J Med Chem 2011; 54:2378-90. [PMID: 21391684 DOI: 10.1021/jm101530j] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Haloperidol (HP), a neuroleptic drug, shows high affinity toward σ receptors (SR). HP and reduced-HP at higher concentration were known to induce apoptosis in SR-overexpressing carcinomas and melanomas. Herein, we report the development of cationic lipid-conjugated haloperidol as a new class of anticancer therapeutics. In comparison to HP, the C-8 carbon chain analogue (HP-C8) showed significantly high, SR-assisted antiproliferative activity against cancer cells via caspase-3-mediated apoptosis and down-regulation of pAkt. Moreover, melanoma tumor aggressiveness in HP-C8-treated mice was significantly lower than that in HP-treated mice. HP-C8 simultaneously reduced Akt-protein level and increased Bax/Bcl-2 ratio in vascular endothelial cells, thereby indicating a possible protein kinase down-regulatory and apoptosis inducing role in tumor-associated vascular cells. In conclusion, we developed σ receptor-targeting cationic lipid-modified HP derivatives as a promising class of anticancer therapeutic that concurrently affects cancer and tumor environment associated angiogenic vascular cells through induction of apoptosis and Akt protein down-regulation.
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Affiliation(s)
- Krishnendu Pal
- Division of Lipid Science and Technology, Indian Institute of Chemical Technology, Hyderabad, Andhra Pradesh 500007, India
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Antiproliferative activity of phenylbutyrate ester of haloperidol metabolite II [(±)-MRJF4] in prostate cancer cells. Eur J Med Chem 2010; 46:433-8. [PMID: 21055848 DOI: 10.1016/j.ejmech.2010.10.012] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2010] [Accepted: 10/11/2010] [Indexed: 11/20/2022]
Abstract
Complex mechanisms of prostate cancer progression prompt to novel therapeutic strategies concerning a combination of drugs or of single molecules able to interact with more crucial targets. Histone deacetylase inhibitors and sigma ligands with mixed σ(1) antagonist and σ(2) agonist properties were proposed as new potential tools for treatment of prostate cancer. (±)-MRJF4 was synthesized as phenylbutyrate ester of haloperidol metabolite II, which is a molecule consisting of a histone deacetilase inhibitor (4-phenylbutyric acid) and a sigma ligand (haloperidol metabolite II). Antiproliferatives activities of 4-phenylbutyric acid, haloperidol metabolite II, equimolar mixture of both compounds and (±)-MRJF4 were evaluated in vitro on LNCaP and PC3 prostate cancer cells. Preliminary binding studies of (±)-MRJF4 for σ(1), σ(2), D(2) and D(3) receptors and inhibition HDAC activity were reported. MTT cell viability assays highlighted a notable increase of antiproliferative activity of (±)-MRJF4 (IC(50) = 11 and 13 μM for LNCaP and PC3, respectively) compared to 4-phenylbutyric acid, haloperidol metabolite II and the respective equimolar pharmacological association. (±)-MRJF4 was also used in combination with σ(1) agonist (+)-pentazocine and σ(2) antagonist AC927 in order to evaluate the role of σ receptor subtypes in prostate cancer cell death.
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Hajipour AR, Fontanilla D, Chu UB, Arbabian M, Ruoho AE. Synthesis and characterization of N,N-dialkyl and N-alkyl-N-aralkyl fenpropimorph-derived compounds as high affinity ligands for sigma receptors. Bioorg Med Chem 2010; 18:4397-404. [PMID: 20493718 PMCID: PMC3565575 DOI: 10.1016/j.bmc.2010.04.078] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2009] [Revised: 04/23/2010] [Accepted: 04/25/2010] [Indexed: 11/20/2022]
Abstract
The sigma-1 receptor is a unique non-opioid, non-PCP binding site that has been implicated in many different pathophysiological conditions including psychosis, drug addiction, retinal degeneration and cancer. Based on the structure of fenpropimorph, a high affinity (K(i)=0.005 nM)(1) sigma-1 receptor ligand and strong inhibitor of the yeast sterol isomerase (ERG2), we previously deduced a basic sigma-1 receptor pharmacophore or chemical backbone composed of a phenyl ring attached to a di-substituted nitrogen atom via an alkyl chain.(2) Here, we report the design and synthesis of various N,N-dialkyl or N-alkyl-N-aralkyl derivatives based on this pharmacophore as well as their binding affinities to the sigma-1 receptor. We introduce three high affinity sigma-1 receptor compounds, N,N-dibutyl-3-(4-fluorophenyl)propylamine (9), N,N-dibutyl-3-(4-nitrophenyl)propylamine (3), and N-propyl-N'-4-aminophenylethyl-3-(4-nitrophenyl)propylamine (20) with K(i) values of 17.7 nM, 0.36 nM, and 6 nM, respectively. In addition to sigma receptor affinity, we show through cytotoxicity assays that growth inhibition of various tumor cell lines occurs with our high affinity N,N-dialkyl or N-alkyl-N-aralkyl derivatives.
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Affiliation(s)
- Abdol R. Hajipour
- Department of Pharmacology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706
- Pharmaceutical Research Laboratory, Department of Chemistry, Isfahan University of Technology, Isfahan 84156, IR Iran
| | - Dominique Fontanilla
- Department of Pharmacology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706
| | - Uyen B. Chu
- Department of Pharmacology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706
| | - Marty Arbabian
- Department of Pharmacology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706
| | - Arnold E. Ruoho
- Department of Pharmacology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706
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Abstract
Originally considered an enigmatic protein, the sigma-1 receptor has recently been identified as a unique ligand-regulated molecular chaperone in the endoplasmic reticulum of cells. This discovery causes us to look back at the many proposed roles of this receptor, even before its molecular function was identified, in many diseases such as methamphetamine or cocaine addiction, amnesia, pain, depression, Alzheimer's disease, stroke, retinal neuroprotection, HIV infection, and cancer. In this review, we examine the reports that have clearly shown an agonist-antagonist relationship regarding sigma-1 receptors in models of those diseases and also review the relatively known mechanisms of action of sigma-1 receptors in an attempt to spur the speculation of readers on how the sigma-1 receptor at the endoplasmic reticulum might relate to so many diseases. We found that the most prominent action of sigma-1 receptors in biological systems including cell lines, primary cultures, and animals is the regulation and modulation of voltage-regulated and ligand-gated ion channels, including Ca(2+)-, K(+)-, Na(+), Cl(-), and SK channels, and NMDA and IP3 receptors. We found that the final output of the action of sigma-1 receptor agonists is to inhibit all above-mentioned voltage-gated ion channels, while they potentiate ligand-gated channels. The inhibition or potentiation induced by agonists is blocked by sigma-1 receptor antagonists. Other mechanisms of action of sigma-1 receptors, and to some extent those of sigma-2 receptors, were also considered. We conclude that the sigma-1 and sigma-2 receptors represent potential fruitful targets for therapeutic developments in combating many human diseases.
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Affiliation(s)
- Tangui Maurice
- Team II Endogenous Neuroprotection in Neurodegenerative Diseases, INSERM U. 710, 34095 Montpellier Cedex 5, France
- University of Montpellier II, EPHE, CC 105, Place Eugene Bataillon, 34095 Montpellier Cedex 5, France
- EPHE, 75017 Paris, France
| | - Tsung-Ping Su
- Cellular Pathobiology Section, Cellular Neurobiology Research Branch, IRP, NIDA-NIH, Suite 3304, 333 Cassell Drive, Baltimore, MD 21224
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Rybczynska AA, Dierckx RA, Ishiwata K, Elsinga PH, van Waarde A. Cytotoxicity of σ-Receptor Ligands Is Associated with Major Changes of Cellular Metabolism and Complete Occupancy of the σ-2 Subpopulation. J Nucl Med 2008; 49:2049-56. [DOI: 10.2967/jnumed.108.053876] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Debeir O, Mégalizzi V, Warzée N, Kiss R, Decaestecker C. Videomicroscopic extraction of specific information on cell proliferation and migration in vitro. Exp Cell Res 2008; 314:2985-98. [PMID: 18598694 DOI: 10.1016/j.yexcr.2008.06.010] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2008] [Revised: 06/10/2008] [Accepted: 06/10/2008] [Indexed: 02/04/2023]
Abstract
In vitro cell imaging is a useful exploratory tool for cell behavior monitoring with a wide range of applications in cell biology and pharmacology. Combined with appropriate image analysis techniques, this approach has been shown to provide useful information on the detection and dynamic analysis of cell events. In this context, numerous efforts have been focused on cell migration analysis. In contrast, the cell division process has been the subject of fewer investigations. The present work focuses on this latter aspect and shows that, in complement to cell migration data, interesting information related to cell division can be extracted from phase-contrast time-lapse image series, in particular cell division duration, which is not provided by standard cell assays using endpoint analyses. We illustrate our approach by analyzing the effects induced by two sigma-1 receptor ligands (haloperidol and 4-IBP) on the behavior of two glioma cell lines using two in vitro cell models, i.e., the low-density individual cell model and the high-density scratch wound model. This illustration also shows that the data provided by our approach are suggestive as to the mechanism of action of compounds, and are thus capable of informing the appropriate selection of further time-consuming and more expensive biological evaluations required to elucidate a mechanism.
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Affiliation(s)
- Olivier Debeir
- Laboratory of Image Synthesis and Analysis, Faculty of Applied Science, Université Libre de Bruxelles, Brussels, Belgium
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27
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de Oca J, Azuara D, Sanchez-Santos R, Navarro M, Capella G, Moreno V, Sola A, Hotter G, Biondo S, Osorio A, Martí-Ragué J, Rafecas A. Caspase-3 activity, response to chemotherapy and clinical outcome in patients with colon cancer. Int J Colorectal Dis 2008; 23:21-7. [PMID: 17805550 DOI: 10.1007/s00384-007-0362-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/03/2007] [Indexed: 02/04/2023]
Abstract
BACKGROUND AND AIMS The prognostic value of the degree of apoptosis in colorectal cancer is controversial. This study evaluates the putative clinical usefulness of measuring caspase-3 activity as a prognostic factor in colonic cancer patients receiving 5-fluoracil adjuvant chemotherapy. MATERIALS AND METHODS We evaluated caspase-3-like protease activity in tumours and in normal colon tissue. Specimens were studied from 54 patients. These patients had either stage III cancer (Dukes stage C) or high-risk stage II cancer (Dukes stage B2 with invasion of adjacent organs, lymphatic or vascular infiltration or carcinoembryonic antigen [CEA] >5). Median follow-up was 73 months. Univariate analysis was performed previously to explore the relation of different variables (age, sex, preoperative CEA, tumour size, Dukes stage, vascular invasion, lymphatic invasion, caspase-3 activity in tumour and caspase-3 activity in normal mucosa) as prognostic factors of tumour recurrence after chemotherapy treatment. Subsequently, a multivariate Cox regression model was performed. RESULTS Median values of caspase-3 activity in tumours were more than twice those in normal mucosa (88.1 vs 40.6 U, p=0.001), showing a statistically significant correlation (r=0.34). Significant prognostic factors of recurrence in multivariate analysis were: male sex (odds ratio, OR=3.53 [1.13-10.90], p=0.02), age (OR=1.09 [1.01-1.18], p=0.03), Dukes stage (OR=1.93 [1.01-3.70]), caspase-3 activity in normal mucosa (OR=1.02 [1.01-1.04], p=0.017) and caspase-3 activity in tumour (OR=1.02 [1.01-1.03], p=0.013). CONCLUSION Low caspase-3 activity in the normal mucosa and tumour are independent prognostic factors of tumour recurrence in patients receiving adjuvant 5-fluoracil-based treatment in colon cancer, correlating with poor disease-free survival and higher recurrence rate.
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Affiliation(s)
- Javier de Oca
- Departament of Surgery, Hospital Universitario de Bellvitge, Feixa Llarga s/n, 08907 LHospitalet de Llobregat, Barcelona, Spain.
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Mégalizzi V, Mathieu V, Mijatovic T, Gailly P, Debeir O, De Neve N, Van Damme M, Bontempi G, Haibe-Kains B, Decaestecker C, Kondo Y, Kiss R, Lefranc F. 4-IBP, a sigma1 receptor agonist, decreases the migration of human cancer cells, including glioblastoma cells, in vitro and sensitizes them in vitro and in vivo to cytotoxic insults of proapoptotic and proautophagic drugs. Neoplasia 2007; 9:358-69. [PMID: 17534441 PMCID: PMC1877975 DOI: 10.1593/neo.07130] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2007] [Revised: 04/03/2007] [Accepted: 04/04/2007] [Indexed: 12/19/2022] Open
Abstract
Although the molecular function of sigma receptors has not been fully defined and the natural ligand(s) is still not known, there is increasing evidence that these receptors and their ligands might play a significant role in cancer biology. 4-(N-benzylpiperidin-4-yl)-4-iodobenzamide (4-IBP), a selective sigma1 agonist, has been used to investigate whether this compound is able to modify: 1) in vitro the migration and proliferation of human cancer cells; 2) in vitro the sensitivity of human glioblastoma cells to cytotoxic drugs; and 3) in vivo in orthotopic glioblastoma and non-small cell lung carcinoma (NSCLC) models the survival of mice co-administered cytotoxic agents. 4-IBP has revealed weak antiproliferative effects on human U373-MG glioblastoma and C32 melanoma cells but induced marked concentration-dependent decreases in the growth of human A549 NSCLC and PC3 prostate cancer cells. The compound was also significantly antimigratory in all four cancer cell lines. This may result, at least in U373-MG cells, from modifications to the actin cytoskeleton. 4-IBP modified the sensitivity of U373-MG cells in vitro to proapoptotic lomustin and proautophagic temozolomide, and markedly decreased the expression of two proteins involved in drug resistance: glucosylceramide synthase and Rho guanine nucleotide dissociation inhibitor. In vivo, 4-IBP increased the antitumor effects of temozolomide and irinotecan in immunodeficient mice that were orthotopically grafted with invasive cancer cells.
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Affiliation(s)
- Véronique Mégalizzi
- Laboratoire de Toxicologie, Institut de Pharmacie, Université Libre de Bruxelles, Brussels, Belgium
| | - Véronique Mathieu
- Laboratoire de Toxicologie, Institut de Pharmacie, Université Libre de Bruxelles, Brussels, Belgium
| | | | - Philippe Gailly
- Département de Physiologie et de Pharmacologie, Université catholique de Louvain, Brussels, Belgium
| | - Olivier Debeir
- Service des Systèmes Logiques et Numériques, Faculté des Sciences Appliquées, Université Libre de Bruxelles, Brussels, Belgium
| | | | - Marc Van Damme
- Laboratoire de Toxicologie, Institut de Pharmacie, Université Libre de Bruxelles, Brussels, Belgium
| | - Gianluca Bontempi
- Machine Learning Group, Department of Computer Science, Université Libre de Bruxelles, Brussels, Belgium
| | - Benjamin Haibe-Kains
- Machine Learning Group, Department of Computer Science, Université Libre de Bruxelles, Brussels, Belgium
- MicroArray Unit, Jules Bordet Institute, Brussels, Belgium
| | - Christine Decaestecker
- Laboratoire de Toxicologie, Institut de Pharmacie, Université Libre de Bruxelles, Brussels, Belgium
| | - Yasuko Kondo
- Department of Neurosurgery, University of Texas M. D. Anderson Cancer Center, Houston, TX, USA
| | - Robert Kiss
- Laboratoire de Toxicologie, Institut de Pharmacie, Université Libre de Bruxelles, Brussels, Belgium
| | - Florence Lefranc
- Laboratoire de Toxicologie, Institut de Pharmacie, Université Libre de Bruxelles, Brussels, Belgium
- Département de Neurochirurgie, Cliniques Universitaires de Bruxelles, Hôpital Erasme, Université Libre de Bruxelles, Brussels, Belgium
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Azzariti A, Colabufo NA, Berardi F, Porcelli L, Niso M, Simone GM, Perrone R, Paradiso A. Cyclohexylpiperazine derivative PB28, a sigma2 agonist and sigma1 antagonist receptor, inhibits cell growth, modulates P-glycoprotein, and synergizes with anthracyclines in breast cancer. Mol Cancer Ther 2006; 5:1807-16. [PMID: 16891467 DOI: 10.1158/1535-7163.mct-05-0402] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
sigma Ligands have recently been shown to have cytotoxic activity, to induce ceramide-dependent/caspase-independent apoptosis, and to down-regulate P-glycoprotein (P-gp) mRNA levels in some mouse and human models. In this study, we verified whether a mixed sigma(2) agonist/sigma(1) antagonist, PB28, was able to have antitumor activity and to enhance anthracycline efficacy in two human breast cancer cell lines, MCF7 and MCF7 ADR, both characterized by significant sigma(2) receptor expression, by high and low sigma(1) receptor expression, and low and high P-gp expression, respectively. In both cell lines, PB28 showed high sigma(2) receptor affinity and low sigma(1) receptor affinity; furthermore, it inhibited cell growth with a clear effect at 48 hours (IC(50) in nanomolar range), a consistent time exposure-independent increase of G(0)-G(1)-phase fraction (of approximately 20% of both cell lines) and caspase-independent apoptosis (15% increased after 1-day drug exposure). PB28 also reduced P-gp expression in a concentration- and time-dependent manner ( approximately 60% in MCF7 and 90% in MCF7 ADR). We showed also a strong synergism between PB28 and doxorubicin by adopting either simultaneous or sequential schedules of the two drugs. We suggest that this synergism could depend on PB28-induced increase of intracellular accumulation of doxorubicin ( approximately 50% in MCF7 and 75% in MCF7 ADR by flow cytometry analysis). In conclusion, we suggest that the sigma(2) agonist PB28 could be an interesting antitumor agent either in monotherapy or in combination with conventional drugs.
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Affiliation(s)
- Amalia Azzariti
- Clinical Experimental Oncology Laboratory, National Cancer Institute, Via Amendola 209, 70125 Bari, Italy.
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Dean CE. Antipsychotic-associated neuronal changes in the brain: toxic, therapeutic, or irrelevant to the long-term outcome of schizophrenia? Prog Neuropsychopharmacol Biol Psychiatry 2006; 30:174-89. [PMID: 16376473 DOI: 10.1016/j.pnpbp.2005.08.019] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/26/2005] [Indexed: 10/25/2022]
Abstract
The increasingly wide-spread use of antipsychotics in both adults and children calls for a detailed examination of antipsychotic-associated neuronal changes in the brain, and whether these changes are toxic, therapeutic, or perhaps irrelevant to the outcome of major psychiatric disorders, especially schizophrenia. In this review we will examine the extensive evidence demonstrating both acute and longer-term antipsychotic-associated neurotoxicity and neuroplasticity, as well as the more specific cellular changes that appear to underlie these phenomena. These include changes in proteins affecting cell survival, impairment of the mitochondrial respiratory chain, increases in DNA fragmentation, injury to dendritic microtubules, increases in dopamine-generated reactive oxygen species, changes in cell morphology, and rapid induction of apoptosis. We shall also examine the correlation between these changes and alterations in gross brain structure. There appears to be a disjunction between the widespread cellular and gross structural brain changes in schizophrenia, and the duration of illness, expression of symptoms, and response to treatment. We shall explore possible explanations for this apparent paradox.
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Affiliation(s)
- Charles E Dean
- Tardive Dyskinesia Assessment Clinic, Minneapolis VA Medical Center, One Veterans Drive, Minneapolis Minnesota 55417, USA.
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Wei Z, Mousseau DD, Dai Y, Cao X, Li XM. Haloperidol induces apoptosis via the sigma2 receptor system and Bcl-XS. THE PHARMACOGENOMICS JOURNAL 2006; 6:279-88. [PMID: 16462815 DOI: 10.1038/sj.tpj.6500373] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Toxicity of the typical antipsychotic haloperidol (HAL) comprises an apoptotic component that we link to pro-apoptotic Bcl-XS in PC12 preneuronal and N2a neuroblastoma cells. The mitochondrial translocation of Bcl-XS and its interaction with the pore-forming voltage-dependent anion channel (VDAC) correlates with the redistribution of cytochrome c and the cleavage of Poly(ADP-ribose) polymerase. Haloperidol-induced apoptosis is mediated by the sigma2 (sigma2) receptor system and does not involve the expected antagonism of the dopamine D(2) receptor, nor is it influenced by Vitamin E- or p53/Bax-mediated events. Pathological relevance is demonstrated by the cytotoxic synergism between HAL and the Alzheimer disease-related peptide beta-amyloid(1-40), which correlates with Bcl-XS expression and its interaction with VDAC, and with cytosolic cytochrome c translocation. These data provide for a unique apoptotic mechanism that could underscore the clinical risks associated with HAL, particularly following chronic regimens or in the elderly.
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Affiliation(s)
- Z Wei
- Neuropsychiatry Research Unit, Department of Psychiatry, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
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32
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Monnet FP. Sigma-1 receptor as regulator of neuronal intracellular Ca2+: clinical and therapeutic relevance. Biol Cell 2005; 97:873-83. [PMID: 16293108 DOI: 10.1042/bc20040149] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Preserving brain function and cognitive faculties during aging and psychiatric diseases (e.g. psychotic, anxiety and affective disorders, dementia) is essential for the self-reliance and quality of life of patients. Cognitive loss involves not only memory, but also motor function. The decrease of catecholaminergic and excitatory neurotransmissions, as well as of protein phosphorylation, have currently been identified as prominent biological markers of the above-mentioned diseases. Such deleterious biological events are well known to occur downstream of a progressive decline of intracellular Ca2+ signalling. This latter constitutes a key target for the neuronal plasticity that has also been reported during aging and psychiatric disorders. Most of the medicines used in psychiatry are active on the sigma-1 receptor. This membrane bound receptor is widely distributed in memory-associated cortical and motor-related brainstem areas, prompting the hypothesis that it might contribute to the pathophysiology of these behavioural brain diseases. The sigma-1 receptor is characterized by a unique mode of action by regulating both Ca2+ entry at the plasma membrane level (i.e. via potassium channels, voltage-sensitive Ca2+ channels) and Ca2+ mobilization from endoplasmic stores [i.e. via Ins(1,4,5)P3 receptors]. This review presents recent data supporting the notion that drugs acting via the endoplasmic reticulum-coupled sigma-1 receptor might reverse these deleterious events by restoring both extra- and intra-cellular Ca(2+)-dependent neuronal responses.
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Affiliation(s)
- François P Monnet
- Etablissement Public de Santé Charcot, 30 rue Marc Laurent, 78370 Plaisir Cedex, and INSERM, U705, CNRS, UMR 7157, Universités Paris 7 et 5, F-75475 Paris cedex 10, France.
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Abstract
Sigma receptors are membrane-bound proteins that are overexpressed in certain human malignancies including breast cancer. These receptors show very high affinity for various sigma ligands including neuroleptics like haloperidol. We hypothesized that in associating haloperidol-linked lipid into the cationic lipid-DNA complex, we can specifically target and deliver genes to breast cancer cells that overexpress sigma receptors. In the present study, haloperidol was chemically modified to conjugate at the distal end of the polyethylene glycollinked phospholipid, which was then incorporated into the cationic liposome known to condense and deliver genes inside cells. The resulting haloperidol-conjugated targeted lipoplex showed at least 10-fold higher (p < 0.001) reporter gene expression in MCF-7 cells than control lipoplex. The reporter gene expression of the targeted lipoplex was significantly blocked by haloperidol (p < 0.001) and by another sigma ligand, 1,3-ditolylguanidine (p < 0.001) in the majority of cationic lipid to DNA charge ratios (+/-). Spironolactone-mediated sigma receptor down-regulation enabled MCF-7 to show 10-fold lower transgene expression with targeted lipoplex compared with that obtained in spironolactone-untreated cells. The targeted lipoplex generated nonspecific gene expression in sigma receptor-nonexpressing human cancer cells such as Hela, KB, HepG2, and Chinese hamster ovary cells. Moreover, the transgene expression remained unabated in physiologically relevant serum concentrations. This is the first study to demonstrate that haloperidol-targeted gene delivery systems can mediate efficient targeting of genes to sigma receptor-overexpressing breast cancer cells, thereby becoming a novel class of therapeutics for the treatment of human cancers.
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Affiliation(s)
- Amarnath Mukherjee
- Division of Lipid Science and Technology, Indian Institute of Chemical Technology, Hyderabad 500007, India
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Wang B, Rouzier R, Albarracin CT, Sahin A, Wagner P, Yang Y, Smith TL, Meric-Bernstam F, Marcelo Aldaz C, Marcelo AC, Hortobagyi GN, Pusztai L. Expression of sigma 1 receptor in human breast cancer. Breast Cancer Res Treat 2005; 87:205-14. [PMID: 15528963 DOI: 10.1007/s10549-004-6590-0] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The sigma 1 receptor (S1R) represents a unique drug-binding site that is distinct from any other receptors. We examined S1R expression in human breast cancer and assessed the activity of S1R ligands in breast cancer cell lines. One-hundred nine breast specimens from normal breast, benign breast disease and cancer were examined with immunohistochemistry or RT-PCR and six different cell lines were also evaluated. S1R mRNA overexpression was detected in 64% of breast cancers compared to normal breast tissue. Immunohistochemistry showed positive epithelial cell staining in 60% of invasive and 41% of in situ cancers, 75% of ductal hyperplasia and in 33% of normal breast. The pattern of expression was more diffuse in invasive breast carcinoma compared to other conditions (p = 0.02). S1R expression was neither a prognostic nor a predictive factor for efficacy of adjuvant chemotherapy but the study only included 58 cancer patients and therefore the statistical power is limited. MDA-MB-361, MDA-MB-435, BT20 and MCF7 cells all expressed S1R protein by Western blot. The non-specific S1R ligands haloperidol, reduced haloperidol and progesterone produced a dose-dependent inhibition of the growth at high (>10 microM) concentrations. Reduced haloperidol also showed additive cytotoxic effects when combined with doxorubicin, vinorelbine , paclitaxel and docetaxel in vitro. The S1R-specific ligand, SKF 10047 demonstrated the least growth inhibitory activity and showed no interaction with chemotherapy. These results demonstrate that some normal and most neoplastic breast epithelial cells and cell lines commonly express S1R. High concentrations of haloperidol inhibit the growth of these cells and potentiate the effect of chemotherapy in vitro.
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Affiliation(s)
- B Wang
- Department of Breast Medical Oncology, The University of Texas MD, Anderson Cancer Center, TX 77030-4009, USA
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35
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Abstract
The sigma (sigma) receptor and its agonists have been implicated in a myriad of cellular functions, biological processes and diseases. Whereas the precise molecular mechanism(s) of sigma receptors and their involvement in cancer cell biology have not been elucidated, recent work has started to shed some light on these issues. A molecular model has been proposed for the cloned sigma1 receptor; the precise molecular nature of the sigma2 receptor remains unknown. sigma receptors have been found to be frequently up-regulated in human cancer cells and tissues. sigma2 receptor drugs particularly have been shown to have antiproliferative effects. An interesting possibility is that sigma and/or sigma1 drugs could produce anticancerous effects by modulating ion channels. As well as proliferation, a variety of other metastatic cellular behaviors such as adhesion, motility, and secretion may also be affected. Other mechanisms of sigma receptor action may involve interaction with ankyrin and modulation of intracellular Ca(2+) and sphingolipid levels. Although more research is needed to further define the molecular physiology of sigma receptors, their involvement in the cellular pathophysiology of cancer raises the possibility that sigma drugs could be useful as novel therapeutic agents.
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Affiliation(s)
- Ebru Aydar
- Department of Biological Sciences, Sir Alexander Fleming Building, Imperial College, South Kensington Campus, London SW7 2AZ, United Kingdom.
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36
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Spruce BA, Campbell LA, McTavish N, Cooper MA, Appleyard MVL, O'Neill M, Howie J, Samson J, Watt S, Murray K, McLean D, Leslie NR, Safrany ST, Ferguson MJ, Peters JA, Prescott AR, Box G, Hayes A, Nutley B, Raynaud F, Downes CP, Lambert JJ, Thompson AM, Eccles S. Small molecule antagonists of the sigma-1 receptor cause selective release of the death program in tumor and self-reliant cells and inhibit tumor growth in vitro and in vivo. Cancer Res 2004; 64:4875-86. [PMID: 15256458 DOI: 10.1158/0008-5472.can-03-3180] [Citation(s) in RCA: 138] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The acquisition of resistance to apoptosis, the cell's intrinsic suicide program, is essential for cancers to arise and progress and is a major reason behind treatment failures. We show in this article that small molecule antagonists of the sigma-1 receptor inhibit tumor cell survival to reveal caspase-dependent apoptosis. sigma antagonist-mediated caspase activation and cell death are substantially attenuated by the prototypic sigma-1 agonists (+)-SKF10,047 and (+)-pentazocine. Although several normal cell types such as fibroblasts, epithelial cells, and even sigma receptor-rich neurons are resistant to the apoptotic effects of sigma antagonists, cells that can promote autocrine survival such as lens epithelial and microvascular endothelial cells are as susceptible as tumor cells. Cellular susceptibility appears to correlate with differences in sigma receptor coupling rather than levels of expression. In susceptible cells only, sigma antagonists evoke a rapid rise in cytosolic calcium that is inhibited by sigma-1 agonists. In at least some tumor cells, sigma antagonists cause calcium-dependent activation of phospholipase C and concomitant calcium-independent inhibition of phosphatidylinositol 3'-kinase pathway signaling. Systemic administration of sigma antagonists significantly inhibits the growth of evolving and established hormone-sensitive and hormone-insensitive mammary carcinoma xenografts, orthotopic prostate tumors, and p53-null lung carcinoma xenografts in immunocompromised mice in the absence of side effects. Release of a sigma receptor-mediated brake on apoptosis may offer a new approach to cancer treatment.
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Affiliation(s)
- Barbara A Spruce
- Department of Surgery and Molecular Oncology, The University of Dundee, Ninewells Hospital and Medical School, Dundee DD1 9SY, Scotland, UK.
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37
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Gilmore DL, Liu Y, Matsumoto RR. Review of the pharmacological and clinical profile of rimcazole. CNS DRUG REVIEWS 2004; 10:1-22. [PMID: 14978511 PMCID: PMC6741722 DOI: 10.1111/j.1527-3458.2004.tb00001.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Rimcazole is a carbazole derivative that acts in part as a sigma receptor antagonist. Wellcome Research Laboratories introduced this compound during the 1980s when it was hypothesized to be a novel antipsychotic with an improved side effect profile. However, subsequent clinical trials demonstrated that rimcazole lacked efficacy in schizophrenic patients and it is now primarily used as an experimental tool. In addition to its actions as a sigma receptor antagonist, rimcazole also has high affinity for dopamine transporters, and in recent years it has served as a lead compound for the development of novel dopamine transporter ligands. Although rimcazole cannot be considered a selective ligand for sigma receptors, the recent development of other selective agonists and antagonists for sigma receptors have aided in clarifying the involvement of these receptors in the actions of rimcazole. Many of the physiological and behavioral effects of rimcazole can in fact be ascribed to its action as a sigma receptor antagonist, although there are exceptions. Rimcazole is likely to have a continued role in elucidating sigma receptor function in either in vitro or in vivo systems where sigma receptor-mediated effects can be studied independently of the influence of dopamine and serotonin transporters.
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Affiliation(s)
- Deborah L. Gilmore
- Department of Pharmaceutical Sciences, University of Oklahoma Health Sciences Center, Oklahoma City, OK
| | - Yun Liu
- Department of Pharmaceutical Sciences, University of Oklahoma Health Sciences Center, Oklahoma City, OK
| | - Rae R. Matsumoto
- Department of Pharmaceutical Sciences, University of Oklahoma Health Sciences Center, Oklahoma City, OK
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Bertolesi GE, Shi C, Elbaum L, Jollimore C, Rozenberg G, Barnes S, Kelly MEM. The Ca(2+) channel antagonists mibefradil and pimozide inhibit cell growth via different cytotoxic mechanisms. Mol Pharmacol 2002; 62:210-9. [PMID: 12130671 DOI: 10.1124/mol.62.2.210] [Citation(s) in RCA: 101] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We show that mitogenic cells expressing T-type Ca(2+) channels (T-channels) are more sensitive to the antiproliferative effects of the drugs pimozide and mibefradil than cells without significant T-channel expression. The growth of Y79 and WERI-Rb1 retinoblastoma cells, as well as MCF7 breast cancer epithelial cells, all of which express T-channel current and mRNA for T-channel subunits, is inhibited by pimozide and mibefradil with IC(50) values between 0.6 and 1.5 microM. Proliferation of glioma C6 cells, which show little T-channel expression, is less sensitive to these drugs (IC(50) = 8 and 5 microM for pimozide and mibefradil, respectively). Neither drug seems to alter cell cycle or the expression of cyclins. Although this strong correlation between T-channel expression and growth inhibition exists, the following results suggest that the drugs inhibit cell growth via different cytotoxic pathways: 1) pimozide and mibefradil have additive effects on T-channel current inhibition, whereas the antiproliferative activity of the drugs together is synergistic; 2) an increase in the number of apoptotic Y79 and MCF7 cells and a decrease in the mRNA for the antiapoptotic gene Bcl-2 is detected only in pimozide-treated cells, whereas in mibefradil-treated cells, the toxicity is primarily necrotic; and 3) growth inhibition by mibefradil is reduced in Y79 cells transfected with T-channel antisense and in differentiated Y79 cells (which have decreased T-channel expression), but growth inhibition by pimozide is affected to a lesser extent. These results suggest that pimozide and mibefradil inhibit cell proliferation via different cytotoxic pathways and that in the case of pimozide, it is unlikely that this effect is mediated solely by T-channel inhibition.
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Affiliation(s)
- Gabriel E Bertolesi
- Laboratory of Retina and Optic Nerve Research, Department of Ophthalmology, Dalhousie University, Halifax, Nova Scotia, Canada
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39
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Wilke RA, Mehta RP, Lupardus PJ, Chen Y, Ruoho AE, Jackson MB. Sigma receptor photolabeling and sigma receptor-mediated modulation of potassium channels in tumor cells. J Biol Chem 1999; 274:18387-92. [PMID: 10373444 DOI: 10.1074/jbc.274.26.18387] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Recent work has indicated that sigma receptor ligands can modulate potassium channels. However, the only sigma receptor characterized at the molecular level has a novel structure unlike any other receptor known to modulate ion channels. This 26-kDa protein has a hydropathy profile suggestive of a single membrane-spanning domain, with no apparent regions capable of G-protein activation or protein phosphorylation. In the present study patch clamp techniques and photoaffinity labeling were used in DMS-114 cells (a tumor cell line known to express sigma receptors) to investigate the role of the 26-kDa protein in ion channel modulation and probe the mechanism of signal transduction. The sigma receptor ligands N-allylnormetazocine (SKF10047), ditolylguanidine, and (+/-)-2-(N-phenylethyl-N-propyl)-amino-5-hydroxytetralin all inhibited voltage-activated potassium current (IK). Iodoazidococaine (IAC), a high affinity sigma receptor photoprobe, produced a similar inhibition in IK, and when cell homogenates were illuminated in the presence of IAC, a protein with a molecular mass of 26 kDa was covalently labeled. Photolabeling of this protein by IAC was inhibited by SKF10047 with half-maximal effect at 7 microM. SKF10047 also inhibited IK with a similar EC50 (14 microM). Thus, physiological responses to sigma receptor ligands are mediated by a protein with the same molecular weight as the cloned sigma receptor. This indicates that ion channel modulation is indeed mediated by this novel protein. Physiological responses were the same when cells were perfused internally with either guanosine 5'-O-(2-thiodiphosphate) or GTP, indicating that signal transduction is independent of G-proteins. These results demonstrate that ion channels can be modulated by a receptor that does not have seven membrane-spanning domains and does not employ G-proteins. Sigma receptors thus modulate ion channels by a novel transduction mechanism.
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Affiliation(s)
- R A Wilke
- Department of Medicine, University of Wisconsin School of Medicine, Madison, Wisconsin 53706, USA
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40
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Zamora PO, Moody TW, John CS. Increased binding to sigma sites of N-[1'(2-piperidinyl)ethyl)-4-[I-125]-iodobenzamide (I-125-PAB) with onset of tumor cell proliferation. Life Sci 1998; 63:1611-8. [PMID: 9806214 DOI: 10.1016/s0024-3205(98)00430-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
This study evaluated if the density of sigma sites was modulated following stimulation of mitosis and progression through the cell cycle. The sigma ligand N-[1'(2-piperidinyl)ethyl)-4-[I-125]-iodobenzamide (I-125-PAB) was a binding probe on the mammary tumor cell lines T47D and MCF-7, and the prostate tumor cell line DU-145. Cells at low density and in log phase growth bound more I-125-IPAB than those at high density at or the near plateau phase. Stimulation of mitosis with insulin or fresh 10% serum increased I-125-IPAB binding in all three cell lines. In cell-cycle synchronized cells, the highest amount of binding was found in cells treated with colcemid to block cells in the M-phase, while the lowest amount of binding was found in cells treated with low serum to block the cells in G1. Cells treated with aphidicolin to block cells at G1/S also bound less than cells block in the M-phase. Collectively, these results support a direct correlation between I-125-PAB binding and proliferative status, and suggest an up-regulation of sigma binding sites prior to mitosis.
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Affiliation(s)
- P O Zamora
- Radiopharmaceutical Research, Department of Radiology, The George Washington University Medical Center, Washington, DC 20037, USA
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41
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Strobl JS, Melkoumian Z, Peterson VA, Hylton H. The cell death response to gamma-radiation in MCF-7 cells is enhanced by a neuroleptic drug, pimozide. Breast Cancer Res Treat 1998; 51:83-95. [PMID: 9877031 DOI: 10.1023/a:1006046604062] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Neuroleptic drugs that bind sigma sites were tested for their ability to inhibit growth and radiosensitize MCF-7 human breast cancer cells. Inhibition of growth by approximately 50% occurred in cells exposed to pimozide (0.6 microM), haloperidol (10 microM), and the sigma ligand DTG (1,3-di(2-tolyl)guanidine, 20 microM), but no growth inhibition occurred in cells exposed to clozapine, a neuroleptic drug lacking sigma binding activity, or dextromethorphan, a selective sigma 1 binding ligand. Pimozide (2.5 microM), but not haloperidol (3.6 microM), enhanced the sensitivity of MCF-7 cells to gamma radiation in clonogenic survival assays. Pimozide significantly decreased MCF-7 clonogenic survival following a 5 or 8 Gy dose of gamma radiation, and the dose of radiation required for 1% survival (survival enhancement ratio, SER) was decreased by a factor of 2. Exposure of normal WI-38 human embryonic lung cells to pimozide did not increase their sensitivity to gamma radiation. Pimozide (2.5 microM) activated early apoptotic changes in MCF-7 cells that were detected by the uptake of Hoechst 33342 dye, and 10 microM pimozide activated a complete apoptotic pathway resulting in the death of > 90% of the cells within 24 hours. MCF-7 cells exposed to gamma radiation alone (8 Gy) showed giant cell formation, mitotic arrest, and a limited degree of apoptosis and necrosis. Within 50 hours of treatment with a combination of radiation and pimozide, cell numbers were sharply reduced compared with cultures exposed to either radiation or pimozide alone. We conclude that pimozide augmented the sensitivity of MCF-7 cells to radiation-induced cell killing through a mechanism not shared by haloperidol, but suggest that concentration of pimozide in MCF-7 cells as a result of an enrichment of sigma 2 sites might target the radiosensitization.
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Affiliation(s)
- J S Strobl
- Department of Pharmacology & Toxicology, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown 26506, USA
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42
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Tsao LI, Su TP. IP3 receptor antagonist heparin uncompetitively inhibits [3H](+)-SKF-10047 binding to sigma receptors. Eur J Pharmacol 1996; 311:R1-2. [PMID: 8884243 DOI: 10.1016/0014-2999(96)00533-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Interaction of sigma receptors with intracellular Ca2+ channel blocker and modulators was examined. Ryanodine and inositol 1,4,5-trisphosphate (IP3) did not inhibit [3H](+)-N-allylnormetazocine ([3H](+)-SKF-10047) binding to sigma receptors from either brain microsomal fractions or liver membrane extracts of the rat. However, the IP3 receptor antagonist heparin inhibited [3H](+)-SKF-10047 to sigma receptors in an uncompetitive manner with a Ki of 93 microM. These results suggest that sigma receptors may bear some relationship with IP3 receptor associated proteins or channels.
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Affiliation(s)
- L I Tsao
- Unit on Pathobiology, National Institute on Drug Abuse/N.I.H., Baltimore, MD 21224, USA
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