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Velasco G, Hernández-Tiedra S, Dávila D, Lorente M. The use of cannabinoids as anticancer agents. Prog Neuropsychopharmacol Biol Psychiatry 2016; 64:259-66. [PMID: 26071989 DOI: 10.1016/j.pnpbp.2015.05.010] [Citation(s) in RCA: 104] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2015] [Revised: 05/18/2015] [Accepted: 05/19/2015] [Indexed: 12/11/2022]
Abstract
It is well-established that cannabinoids exert palliative effects on some cancer-associated symptoms. In addition evidences obtained during the last fifteen years support that these compounds can reduce tumor growth in animal models of cancer. Cannabinoids have been shown to activate an ER-stress related pathway that leads to the stimulation of autophagy-mediated cancer cell death. In addition, cannabinoids inhibit tumor angiogenesis and decrease cancer cell migration. The mechanisms of resistance to cannabinoid anticancer action as well as the possible strategies to develop cannabinoid-based combinational therapies to fight cancer have also started to be explored. In this review we will summarize these observations (that have already helped to set the bases for the development of the first clinical studies to investigate the potential clinical benefit of using cannabinoids in anticancer therapies) and will discuss the possible future avenues of research in this area.
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Affiliation(s)
- Guillermo Velasco
- Department of Biochemistry and Molecular Biology I, School of Biology, Complutense University of Madrid, Spain; Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC), Spain.
| | - Sonia Hernández-Tiedra
- Department of Biochemistry and Molecular Biology I, School of Biology, Complutense University of Madrid, Spain; Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC), Spain
| | - David Dávila
- Department of Biochemistry and Molecular Biology I, School of Biology, Complutense University of Madrid, Spain; Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC), Spain
| | - Mar Lorente
- Department of Biochemistry and Molecular Biology I, School of Biology, Complutense University of Madrid, Spain; Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC), Spain
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52
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Falasca M, Ferro R. Role of the lysophosphatidylinositol/GPR55 axis in cancer. Adv Biol Regul 2016; 60:88-93. [PMID: 26588872 DOI: 10.1016/j.jbior.2015.10.003] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Revised: 10/02/2015] [Accepted: 10/02/2015] [Indexed: 06/05/2023]
Abstract
Lysophosphatidylinositol (LPI) is a well-known bioactive lipid that is able to activate signalling cascades relevant to cell proliferation, migration, survival and tumourigenesis. It is well-established that the G protein-coupled receptor 55 (GPR55) is the specific receptor for LPI. Several investigations have demonstrated that the signalling pathways activated by LPI through its receptor GPR55 play a pivotal role in different cancer type. This review focuses on the role of the LPI/GPR55 axis, in particular with regards to its pharmacological potential therapeutic exploitation.
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Affiliation(s)
- Marco Falasca
- Metabolic Signalling Group, School of Biomedical Sciences, CHIRI Biosciences, Curtin University, Perth, Western Australia 6102, Australia; Queen Mary University of London, Barts and The London School of Medicine and Dentistry, Blizard Institute, 4 Newark Street, London E1 2AT, UK.
| | - Riccardo Ferro
- Queen Mary University of London, Barts and The London School of Medicine and Dentistry, Blizard Institute, 4 Newark Street, London E1 2AT, UK
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53
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Molecular mechanisms of target recognition by lipid GPCRs: relevance for cancer. Oncogene 2015; 35:4021-35. [DOI: 10.1038/onc.2015.467] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 11/02/2015] [Accepted: 11/02/2015] [Indexed: 12/18/2022]
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Kargl J, Andersen L, Hasenöhrl C, Feuersinger D, Stančić A, Fauland A, Magnes C, El-Heliebi A, Lax S, Uranitsch S, Haybaeck J, Heinemann A, Schicho R. GPR55 promotes migration and adhesion of colon cancer cells indicating a role in metastasis. Br J Pharmacol 2015; 173:142-54. [PMID: 26436760 DOI: 10.1111/bph.13345] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 08/31/2015] [Accepted: 09/24/2015] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND AND PURPOSE Tumour cell migration and adhesion constitute essential features of metastasis. G-protein coupled receptor 55 (GPR55), a lysophospholipid receptor, has been shown to play an important role in carcinogenesis. Here, we investigated the involvement of GPR55 in migration and metastasis of colon cancer cells. EXPERIMENTAL APPROACH Adhesion and migration assays using the highly metastatic colon cancer cell line HCT116 and an in vivo assay of liver metastasis were performed. The GPR55 antagonist CID16020046, cannabidiol, a putative GPR55 antagonist and GPR55 siRNA were used to block GPR55 activity in HCT116 colon cancer cells. KEY RESULTS HCT116 cells showed a significant decrease in adhesion to endothelial cells and in migration after blockade with CID16020046 or cannabidiol. The inhibitory effects of CID16020046 or cannabidiol were averted by GPR55 siRNA knock down in cancer cells. The integrity of endothelial cell monolayers was increased after pretreatment of HCT116 cells with the antagonists or after GPR55 siRNA knockdown while pretreatment with lysophosphatidylinositol (LPI), the endogenous ligand of GPR55, decreased integrity of the monolayers. LPI also induced migration in GPR55 overexpressing HCT116 cells that was blocked by GPR55 antagonists. In a mouse model of metastasis, the arrest of HCT116 cancer cells in the liver was reduced after treatment with CID16020046 or cannabidiol. Increased levels of LPI (18:0) were found in colon cancer patients when compared with healthy individuals. CONCLUSIONS AND IMPLICATIONS GPR55 is involved in the migratory behaviour of colon carcinoma cells and may serve as a pharmacological target for the prevention of metastasis. © 2015 The British Pharmacological Society.
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Affiliation(s)
- J Kargl
- Institute of Experimental and Clinical Pharmacology, Medical University of Graz, Graz, Austria
| | - L Andersen
- Institute of Experimental and Clinical Pharmacology, Medical University of Graz, Graz, Austria
| | - C Hasenöhrl
- Institute of Experimental and Clinical Pharmacology, Medical University of Graz, Graz, Austria
| | - D Feuersinger
- Institute of Experimental and Clinical Pharmacology, Medical University of Graz, Graz, Austria
| | - A Stančić
- Institute of Experimental and Clinical Pharmacology, Medical University of Graz, Graz, Austria
| | - A Fauland
- HEALTH - Institute for Biomedicine and Health Sciences, Joanneum Research Forschungsgesellschaft m.b.H., Graz, Austria
| | - C Magnes
- HEALTH - Institute for Biomedicine and Health Sciences, Joanneum Research Forschungsgesellschaft m.b.H., Graz, Austria
| | - A El-Heliebi
- Institute of Cell Biology, Histology and Embryology, Medical University of Graz, Graz, Austria.,Biobank Graz, Medical University of Graz, Graz, Austria
| | - S Lax
- Department of Pathology, General Hospital Graz West, Graz, Austria
| | - S Uranitsch
- Department of Surgery, St John of God Hospital Graz, Graz, Austria
| | - J Haybaeck
- Institute of Pathology, Medical University of Graz, Graz, Austria
| | - A Heinemann
- Institute of Experimental and Clinical Pharmacology, Medical University of Graz, Graz, Austria
| | - R Schicho
- Institute of Experimental and Clinical Pharmacology, Medical University of Graz, Graz, Austria
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55
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Cui X, Liu Y, Wang B, Xian G, Liu X, Tian X, Qin C. Knockdown of GPR137 by RNAi inhibits pancreatic cancer cell growth and induces apoptosis. Biotechnol Appl Biochem 2015; 62:861-7. [PMID: 25471990 DOI: 10.1002/bab.1326] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Accepted: 11/20/2014] [Indexed: 12/13/2022]
Abstract
G-protein-coupled receptors (GPCRs), the largest family of cell-surface molecules involved in a number of biological and pathological processes, have recently emerged as key players in carcinogenesis and cancer progression. Orphan G protein-coupled receptors (oGPCRs) are a group of proteins lacking endogenous ligands. GPR137, one of the novel oGPCR genes, was discovered by homology screening. However, the biological role of GPR137 in cancers has not yet been discussed and is of great therapeutic interest. In this study, we knocked down GPR137 via a lentivirus system in two human pancreatic cancer cell lines BXPC-3 and PANC-1. Knockdown of GPR137 strongly inhibited cell proliferation and colony formation. Flow cytometry showed that cell cycle was arrested in the sub-G1 phase and apoptotic cells were significantly increased after GPR137 knockdown. Western blotting confirmed that GPR137 silencing induced apoptosis due to cleavage of PARP (poly ADP-ribose polymerase) and upregulation of caspase 3. Furthermore, lentivirus-mediated overexpression of GPR137 promoted the proliferation of PANC-1 cells, suggesting GPR137 as a potential oncogene in pancreatic cancer cells. Taken together, our results prove the importance of GPR137 as a crucial regulator in controlling cancer cell growth and apoptosis.
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Affiliation(s)
- Xianping Cui
- Department of Hepatobiliary Surgery, Shandong Provincial Hospital, Shandong University, Jinan, People's Republic of China
| | - Yanguo Liu
- Department of Oncology, Qilu Hospital, Shandong University, Jinan, People's Republic of China
| | - Bo Wang
- Department of immunology, Shandong University School of Medicine, Jinan, People's Republic of China
| | - Guozhe Xian
- Department of Hepatobiliary Surgery, Shandong Provincial Hospital, Shandong University, Jinan, People's Republic of China
| | - Xin Liu
- Department of Hepatobiliary Surgery, Shandong Provincial Hospital, Shandong University, Jinan, People's Republic of China
| | - Xingsong Tian
- Department of Breast and Thyroid Surgery, Shandong Provincial Hospital affiliated to Shandong University, Jinan, People's Republic of China
| | - Chengkun Qin
- Department of Hepatobiliary Surgery, Shandong Provincial Hospital, Shandong University, Jinan, People's Republic of China
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Guy AT, Nagatsuka Y, Ooashi N, Inoue M, Nakata A, Greimel P, Inoue A, Nabetani T, Murayama A, Ohta K, Ito Y, Aoki J, Hirabayashi Y, Kamiguchi H. Glycerophospholipid regulation of modality-specific sensory axon guidance in the spinal cord. Science 2015; 349:974-7. [DOI: 10.1126/science.aab3516] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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57
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Ayakannu T, Taylor AH, Willets JM, Konje JC. The evolving role of the endocannabinoid system in gynaecological cancer. Hum Reprod Update 2015; 21:517-35. [PMID: 25958409 DOI: 10.1093/humupd/dmv022] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Accepted: 04/09/2015] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND The 'endocannabinoid system' (ECS), comprising endogenous ligands (endocannabinoids) and their regulating enzymes, together with the cannabinoid receptors, has attracted a great deal of attention because it affects not only all facets of human reproduction, from gametogenesis through to parturition and beyond, but also targets key mechanisms affecting some hallmarks of cancer. Recent evidence showing that cannabinoid receptors play a very important role in the development of malignancies outside of the reproductive organs suggests a similar role for the ECS in the establishment or continued development of gynaecological malignancy. METHODS Primary papers and review articles, and primary sources within these papers, up to December 2014, on the evolving role of the ECS in cancer, with a special focus on gynaecological cancers, were obtained by Medline and PubMed searches using the search terms: 'cancer', 'cannabinoid', 'endocannabinoid', 'gynaecology' and 'malignancy'. Non-English manuscripts were excluded. RESULTS More than 2100 sources were obtained from which only 112 were specifically important to the topic. Analysis of those articles supports a role of the ECS in gynaecological cancers but leaves many gaps in our knowledge that need to be filled. How some of the relevant receptors are activated and cause changes in cell phenotypes that progress to malignancy remains undiscovered and an area for future research. Increasing evidence suggests that malignant transformation within the female genital tract could be accompanied by deregulation of components of the ECS, acting through rather complex cannabinoid receptor-dependent and receptor-independent mechanisms. CONCLUSIONS The paucity of studies in this area suggests that research using animal models is needed to evaluate endocannabinoid signalling in cancer networks. Future randomized clinical studies should reveal whether endocannabinoids or their derivatives prove to be useful therapeutic targets for gynaecological and other cancers.
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Affiliation(s)
- Thangesweran Ayakannu
- Endocannabinoid Research Group, Reproductive Sciences Section, Department of Cancer Studies and Molecular Medicine, University of Leicester, Leicester LE2 7LX, UK
| | - Anthony H Taylor
- Endocannabinoid Research Group, Reproductive Sciences Section, Department of Cancer Studies and Molecular Medicine, University of Leicester, Leicester LE2 7LX, UK Biosciences, School of Science and Technology, Nottingham Trent University, Clifton Campus, Nottingham NG1 4BU, UK
| | - Jonathan M Willets
- Endocannabinoid Research Group, Reproductive Sciences Section, Department of Cancer Studies and Molecular Medicine, University of Leicester, Leicester LE2 7LX, UK
| | - Justin C Konje
- Endocannabinoid Research Group, Reproductive Sciences Section, Department of Cancer Studies and Molecular Medicine, University of Leicester, Leicester LE2 7LX, UK Department of Obstetrics and Gynaecology, Sidra Medical and Research Centre, Doha P.O. Box 26999, Qatar
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58
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Shore DM, Reggio PH. The therapeutic potential of orphan GPCRs, GPR35 and GPR55. Front Pharmacol 2015; 6:69. [PMID: 25926795 PMCID: PMC4397721 DOI: 10.3389/fphar.2015.00069] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 03/15/2015] [Indexed: 12/19/2022] Open
Abstract
The G protein-coupled receptor (GPCR) superfamily of integral proteins is the largest family of signal transducers, comprised of ∼1000 members. Considering their prevalence and functional importance, it’s not surprising that ∼60% of drugs target GPCRs. Regardless, there exists a subset of the GPCR superfamily that is largely uncharacterized and poorly understood; specifically, more than 140 GPCRs have unknown endogenous ligands—the so-called orphan GPCRs. Orphan GPCRs offer tremendous promise, as they may provide novel therapeutic targets that may be more selective than currently known receptors, resulting in the potential reduction in side effects. In addition, they may provide access to signal transduction pathways currently unknown, allowing for new strategies in drug design. Regardless, orphan GPCRs are an important area of inquiry, as they represent a large gap in our understanding of signal transduction at the cellular level. Here, we focus on the therapeutic potential of two recently deorphanized GPCRs: GPR35/CXCR8 and GPR55. First, GPR35/CXCR8 has been observed in numerous tissues/organ systems, including the gastrointestinal tract, liver, immune system, central nervous system, and cardiovascular system. Not surprisingly, GPR35/CXCR8 has been implicated in numerous pathologies involving these tissues/systems. While several endogenous ligands have been identified, GPR35/CXCR8 has recently been observed to bind the chemokine CXCL17. Second, GPR55 has been observed to be expressed in the central nervous system, adrenal glands, gastrointestinal tract, lung, liver, uterus, bladder, kidney, and bone, as well as, other tissues/organ systems. Likewise, it is not surprising that GPR55 has been implicated in pathologies involving these tissues/systems. GPR55 was initially deorphanized as a cannabinoid receptor and this receptor does bind many cannabinoid compounds. However, the GPR55 endogenous ligand has been found to be a non-cannabinoid, lysophophatidylinositol (LPI) and subsequent high throughput assays have identified other GPR55 ligands that are not cannabinoids and do not bind to either the cannabinoid CB1 and CB2 receptors. Here, we review reports that suggest that GPR35/CXCR8 and GPR55 may be promising therapeutic targets, with diverse physiological roles.
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Affiliation(s)
- Derek M Shore
- Center for Drug Discovery, Department of Chemistry and Biochemistry, University of North Carolina Greensboro Greensboro, NC, USA
| | - Patricia H Reggio
- Center for Drug Discovery, Department of Chemistry and Biochemistry, University of North Carolina Greensboro Greensboro, NC, USA
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59
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He D, Wang J, Zhang C, Shan B, Deng X, Li B, Zhou Y, Chen W, Hong J, Gao Y, Chen Z, Duan C. Down-regulation of miR-675-5p contributes to tumor progression and development by targeting pro-tumorigenic GPR55 in non-small cell lung cancer. Mol Cancer 2015; 14:73. [PMID: 25889562 PMCID: PMC4392735 DOI: 10.1186/s12943-015-0342-0] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Accepted: 03/12/2015] [Indexed: 01/09/2023] Open
Abstract
Background microRNAs are small noncoding RNAs that modulate a variety of cellular processes by regulating multiple targets, which can promote or inhibit the development of malignant behaviors. Accumulating evidence suggests that miR-675-5p plays important roles in human carcinogenesis. However, its precise biological role remains largely elusive. This study examined the role of miR-675-5p in non- small cell lung cancer (NSCLC). Methods The expression of miR-675-5p was analyzed by real-time quantitative PCR (qRT-PCR). The effect of miR-675-5p on proliferation was evaluated through MTT and colony formation assays, and cell migration and invasion were evaluated through transwell assays. The expression of target proteins and downstream molecules was analyzed by western blotting and immunohistochemical staining. The luciferase reporter assay was used to assess the target genes of miR-675-5p in non-small cell lung cancer cells. Results The expression levels of miR-675-5p in NSCLC tissues were significantly reduced compared to those in adjacent non-cancerous tissues (P < 0.001). The expression of miR-675-5p in patients with non-small cell lung cancer had a negative correlation with lymph node metastasis (P < 0.01) and TNM stage (P < 0.05). Down-regulation of miR-675-5p promoted cell growth, proliferation, colony formation, invasion and migration, and promoted the tumorigenicity graft growth of nude mice in vivo (P < 0.01); whereas up-regulation of miR-675-5p had the contrary effects. The luciferase reporter assay showed that GPR55 was a direct target gene of miR-675-5p. Overexpression of miR-675-5p can lead to the down-regulation of GPR55 and its signaling pathway, whereas the effect can be reversed by down-regulation of miR-675-5p expression. Conclusions miR-675-5p functions as a novel tumor suppressor in NSCLC and the anti-oncogenic activity may involve its inhibition of the target gene GPR55. These findings suggest the possibility for miR-675-5p as a therapeutic target in NSCLC. Electronic supplementary material The online version of this article (doi:10.1186/s12943-015-0342-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Dan He
- Key Laboratory of Cancer Proteomics of Chinese Ministry of Health, Institute of Medical Sciences, Xiangya Hospital, Central South University, Xiangya Road 87th, Changsha, 410008, Hunan, PR China.
| | - Jun Wang
- Key Laboratory of Cancer Proteomics of Chinese Ministry of Health, Institute of Medical Sciences, Xiangya Hospital, Central South University, Xiangya Road 87th, Changsha, 410008, Hunan, PR China.
| | - Chunfang Zhang
- Key Laboratory of Cancer Proteomics of Chinese Ministry of Health, Institute of Medical Sciences, Xiangya Hospital, Central South University, Xiangya Road 87th, Changsha, 410008, Hunan, PR China.
| | - Bin Shan
- College of Medical Sciences, Washington State University Spokane, 412 E.Spokane Falls Boulevard, Spokane, WA, 99202, USA.
| | - Xiyun Deng
- Faculty of Basic Medical Sciences, College of Medicine, Hunan Normal University, Changsha, 410013, PR China.
| | - Bin Li
- Key Laboratory of Cancer Proteomics of Chinese Ministry of Health, Institute of Medical Sciences, Xiangya Hospital, Central South University, Xiangya Road 87th, Changsha, 410008, Hunan, PR China.
| | - Yanwu Zhou
- Key Laboratory of Cancer Proteomics of Chinese Ministry of Health, Institute of Medical Sciences, Xiangya Hospital, Central South University, Xiangya Road 87th, Changsha, 410008, Hunan, PR China.
| | - Wei Chen
- Key Laboratory of Cancer Proteomics of Chinese Ministry of Health, Institute of Medical Sciences, Xiangya Hospital, Central South University, Xiangya Road 87th, Changsha, 410008, Hunan, PR China.
| | - Jidong Hong
- Key Laboratory of Cancer Proteomics of Chinese Ministry of Health, Institute of Medical Sciences, Xiangya Hospital, Central South University, Xiangya Road 87th, Changsha, 410008, Hunan, PR China.
| | - Yang Gao
- Key Laboratory of Cancer Proteomics of Chinese Ministry of Health, Institute of Medical Sciences, Xiangya Hospital, Central South University, Xiangya Road 87th, Changsha, 410008, Hunan, PR China.
| | - Zhuchu Chen
- Key Laboratory of Cancer Proteomics of Chinese Ministry of Health, Institute of Medical Sciences, Xiangya Hospital, Central South University, Xiangya Road 87th, Changsha, 410008, Hunan, PR China.
| | - Chaojun Duan
- Key Laboratory of Cancer Proteomics of Chinese Ministry of Health, Institute of Medical Sciences, Xiangya Hospital, Central South University, Xiangya Road 87th, Changsha, 410008, Hunan, PR China.
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New Insights into Antimetastatic and Antiangiogenic Effects of Cannabinoids. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2015; 314:43-116. [DOI: 10.1016/bs.ircmb.2014.10.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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61
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Ahmad R, Wojciech S, Jockers R. Hunting for the function of orphan GPCRs - beyond the search for the endogenous ligand. Br J Pharmacol 2014; 172:3212-28. [PMID: 25231237 DOI: 10.1111/bph.12942] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Revised: 09/04/2014] [Accepted: 09/09/2014] [Indexed: 12/13/2022] Open
Abstract
Seven transmembrane-spanning proteins (7TM), also called GPCRs, are among the most versatile and evolutionary successful protein families. Out of the 400 non-odourant members identified in the human genome, approximately 100 remain orphans that have not been matched with an endogenous ligand. Apart from the classical deorphanization strategies, several alternative strategies provided recent new insights into the function of these proteins, which hold promise for high therapeutic potential. These alternative strategies consist of the phenotypical characterization of organisms silenced or overexpressing orphan 7TM proteins, the search for constitutive receptor activity and formation of protein complexes including 7TM proteins as well as the development of synthetic, surrogate ligands. Taken together, a variety of ligand-independent functions can be attributed to orphan 7TM proteins that range from constitutive activity to complex formation with other proteins and include 'true' orphans for which no ligand exist and 'conditional' orphans that behave like orphans in the absence of ligand and as non-orphans in the presence of ligand.
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Affiliation(s)
- Raise Ahmad
- Institut Cochin, INSERM, Paris, France.,CNRS UMR 8104, Paris, France.,Paris Descartes University, Paris, France
| | - Stefanie Wojciech
- Institut Cochin, INSERM, Paris, France.,CNRS UMR 8104, Paris, France.,Paris Descartes University, Paris, France
| | - Ralf Jockers
- Institut Cochin, INSERM, Paris, France.,CNRS UMR 8104, Paris, France.,Paris Descartes University, Paris, France
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62
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Martínez-Pinilla E, Reyes-Resina I, Oñatibia-Astibia A, Zamarbide M, Ricobaraza A, Navarro G, Moreno E, Dopeso-Reyes I, Sierra S, Rico A, Roda E, Lanciego J, Franco R. CB1 and GPR55 receptors are co-expressed and form heteromers in rat and monkey striatum. Exp Neurol 2014; 261:44-52. [DOI: 10.1016/j.expneurol.2014.06.017] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Revised: 06/13/2014] [Accepted: 06/17/2014] [Indexed: 10/25/2022]
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63
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Balenga NA, Martínez-Pinilla E, Kargl J, Schröder R, Peinhaupt M, Platzer W, Bálint Z, Zamarbide M, Dopeso-Reyes IG, Ricobaraza A, Pérez-Ortiz JM, Kostenis E, Waldhoer M, Heinemann A, Franco R. Heteromerization of GPR55 and cannabinoid CB2 receptors modulates signalling. Br J Pharmacol 2014; 171:5387-406. [PMID: 25048571 DOI: 10.1111/bph.12850] [Citation(s) in RCA: 93] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2013] [Revised: 07/01/2014] [Accepted: 07/14/2014] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND AND PURPOSE Heteromerization of GPCRs is key to the integration of extracellular signals and the subsequent cell response via several mechanisms including heteromer-selective ligand binding, trafficking and/or downstream signalling. As the lysophosphatidylinositol GPCR 55 (GPR55) has been shown to affect the function of the cannabinoid receptor subtype 2 (CB2 receptor) in human neutrophils, we investigated the possible heteromerization of CB2 receptors with GPR55. EXPERIMENTAL APPROACH The direct interaction of human GPR55 and CB2 receptors heterologously expressed in HEK293 cells was assessed by co-immunoprecipitation and bioluminescence resonance energy transfer assays. The effect of cross-talk on signalling was investigated at downstream levels by label-free real-time methods (Epic dynamic mass redistribution and CellKey impedance assays), ERK1/2-MAPK activation and gene reporter assays. KEY RESULTS GPR55 and CB2 receptors co-localized on the surface of HEK293 cells, co-precipitated in membrane extracts and formed heteromers in living HEK293 cells. Whereas heteromerization led to a reduction in GPR55-mediated activation of transcription factors (nuclear factor of activated T-cells, NF-κB and cAMP response element), ERK1/2-MAPK activation was potentiated in the presence of CB2 receptors. CB2 receptor-mediated signalling was also affected by co-expression with GPR55. Label-free assays confirmed cross-talk between the two receptors. CONCLUSIONS AND IMPLICATIONS Heteromers, unique signalling units, form in HEK293 cells expressing GPR55 and CB2 receptors. The signalling by agonists of either receptor was governed (i) by the presence or absence of the partner receptors (with the consequent formation of heteromers) and (ii) by the activation state of the partner receptor.
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Affiliation(s)
- N A Balenga
- Institute for Experimental and Clinical Pharmacology, Medical University of Graz, Graz, Austria
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64
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Moreno E, Andradas C, Medrano M, Caffarel MM, Pérez-Gómez E, Blasco-Benito S, Gómez-Cañas M, Pazos MR, Irving AJ, Lluís C, Canela EI, Fernández-Ruiz J, Guzmán M, McCormick PJ, Sánchez C. Targeting CB2-GPR55 receptor heteromers modulates cancer cell signaling. J Biol Chem 2014; 289:21960-72. [PMID: 24942731 DOI: 10.1074/jbc.m114.561761] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The G protein-coupled receptors CB2 (CB2R) and GPR55 are overexpressed in cancer cells and human tumors. Because a modulation of GPR55 activity by cannabinoids has been suggested, we analyzed whether this receptor participates in cannabinoid effects on cancer cells. Here we show that CB2R and GPR55 form heteromers in cancer cells, that these structures possess unique signaling properties, and that modulation of these heteromers can modify the antitumoral activity of cannabinoids in vivo. These findings unveil the existence of previously unknown signaling platforms that help explain the complex behavior of cannabinoids and may constitute new targets for therapeutic intervention in oncology.
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Affiliation(s)
- Estefanía Moreno
- From the Department of Biochemistry and Molecular Biology, University of Barcelona, 08028 Barcelona, Spain, the Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), 28031 Madrid, Spain, the Institute of Biomedicine of the University of Barcelona, 08028 Barcelona, Spain
| | - Clara Andradas
- the Department of Biochemistry and Molecular Biology I, School of Biology and the Instituto de Investigación Hospital 12 de Octubre, 28041 Madrid, Spain
| | - Mireia Medrano
- From the Department of Biochemistry and Molecular Biology, University of Barcelona, 08028 Barcelona, Spain, the Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), 28031 Madrid, Spain, the Institute of Biomedicine of the University of Barcelona, 08028 Barcelona, Spain
| | - María M Caffarel
- the Department of Biochemistry and Molecular Biology I, School of Biology and
| | - Eduardo Pérez-Gómez
- the Department of Biochemistry and Molecular Biology I, School of Biology and the Instituto de Investigación Hospital 12 de Octubre, 28041 Madrid, Spain
| | - Sandra Blasco-Benito
- the Department of Biochemistry and Molecular Biology I, School of Biology and the Instituto de Investigación Hospital 12 de Octubre, 28041 Madrid, Spain
| | - María Gómez-Cañas
- the Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), 28031 Madrid, Spain, Department of Biochemistry and Molecular Biology III/Instituto Universitario de Investigación en Neuroquímica, School of Medicine, Complutense University, 28040 Madrid, Spain, the Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid 28034, Spain
| | - M Ruth Pazos
- the Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), 28031 Madrid, Spain, Department of Biochemistry and Molecular Biology III/Instituto Universitario de Investigación en Neuroquímica, School of Medicine, Complutense University, 28040 Madrid, Spain
| | - Andrew J Irving
- the Division of Neuroscience, Ninewells Hospital, University of Dundee, Dundee DD1 9SY, United Kingdom, and
| | - Carme Lluís
- From the Department of Biochemistry and Molecular Biology, University of Barcelona, 08028 Barcelona, Spain, the Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), 28031 Madrid, Spain, the Institute of Biomedicine of the University of Barcelona, 08028 Barcelona, Spain
| | - Enric I Canela
- From the Department of Biochemistry and Molecular Biology, University of Barcelona, 08028 Barcelona, Spain, the Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), 28031 Madrid, Spain, the Institute of Biomedicine of the University of Barcelona, 08028 Barcelona, Spain
| | - Javier Fernández-Ruiz
- the Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), 28031 Madrid, Spain, Department of Biochemistry and Molecular Biology III/Instituto Universitario de Investigación en Neuroquímica, School of Medicine, Complutense University, 28040 Madrid, Spain, the Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid 28034, Spain
| | - Manuel Guzmán
- the Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), 28031 Madrid, Spain, the Department of Biochemistry and Molecular Biology I, School of Biology and the Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid 28034, Spain
| | - Peter J McCormick
- From the Department of Biochemistry and Molecular Biology, University of Barcelona, 08028 Barcelona, Spain, the Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), 28031 Madrid, Spain, the Institute of Biomedicine of the University of Barcelona, 08028 Barcelona, Spain, the School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom
| | - Cristina Sánchez
- the Department of Biochemistry and Molecular Biology I, School of Biology and the Instituto de Investigación Hospital 12 de Octubre, 28041 Madrid, Spain,
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65
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Li C, Kong D. Cancer risks from diabetes therapies: evaluating the evidence. Pharmacol Ther 2014; 144:71-81. [PMID: 24844968 DOI: 10.1016/j.pharmthera.2014.05.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Accepted: 05/05/2014] [Indexed: 12/25/2022]
Abstract
Epidemiological studies have identified positive associations between diabetes, obesity and cancer. Insulin, metformin and thiazolidinediones (TDZs) are among the major diabetes therapies that improve glycaemic control by acting via molecular targets including the insulin receptor and insulin-like growth factor pathways, adenosine monophosphate-activated kinase and peroxisome proliferator-activated receptor γ. It is well-established that clinical application of insulin and TDZs is associated with weight gain, but the potential of these therapies to promote tumourigenesis is less well-studied. In addition, although anti-tumour properties of metformin have been proposed, recently published data do not support a protective effect of metformin against cancer in diabetic patients. Given that diabetes and cancer each account for 8% and 13% of global deaths and there is a substantial financial burden incurred by both disorders, developing diabetes therapies that are safe, efficacious and cost-effective has never been more desirable. This timely review examines recent progress in delineating the molecular mechanisms responsible for the anti-diabetic actions of insulin, metformin and TZDs and considers evidence implicating these therapies in cell transformation and tumourigenesis. In addition, since the endocannabinoid signalling system (ECS) is now considered a therapeutic target and biomarker candidate for hyperglycaemia, obesity and cell growth, a brief section covering recent scientific advances regarding the ECS, particularly its functions in regulating glucose metabolism and cell survival, is also included in this review.
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Affiliation(s)
- Chen Li
- Institute of Biomedical Engineering, Chinese Academy of Medical Science, China.
| | - Deling Kong
- Institute of Biomedical Engineering, Chinese Academy of Medical Science, China
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66
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CB2 receptor activation inhibits melanoma cell transmigration through the blood-brain barrier. Int J Mol Sci 2014; 15:8063-74. [PMID: 24815068 PMCID: PMC4057719 DOI: 10.3390/ijms15058063] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 04/04/2014] [Accepted: 04/22/2014] [Indexed: 02/07/2023] Open
Abstract
During parenchymal brain metastasis formation tumor cells need to migrate through cerebral endothelial cells, which form the morphological basis of the blood-brain barrier (BBB). The mechanisms of extravasation of tumor cells are highly uncharacterized, but in some aspects recapitulate the diapedesis of leukocytes. Extravasation of leukocytes through the BBB is decreased by the activation of type 2 cannabinoid receptors (CB2); therefore, in the present study we sought to investigate the role of CB2 receptors in the interaction of melanoma cells with the brain endothelium. First, we identified the presence of CB1, CB2(A), GPR18 (transcriptional variant 1) and GPR55 receptors in brain endothelial cells, while melanoma cells expressed CB1, CB2(A), GPR18 (transcriptional variants 1 and 2), GPR55 and GPR119. We observed that activation of CB2 receptors with JWH-133 reduced the adhesion of melanoma cells to the layer of brain endothelial cells. JWH-133 decreased the transendothelial migration rate of melanoma cells as well. Our results suggest that changes induced in endothelial cells are critical in the mediation of the effect of CB2 agonists. Our data identify CB2 as a potential target in reducing the number of brain metastastes originating from melanoma.
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67
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Simcocks AC, O'Keefe L, Jenkin KA, Mathai ML, Hryciw DH, McAinch AJ. A potential role for GPR55 in the regulation of energy homeostasis. Drug Discov Today 2013; 19:1145-51. [PMID: 24370891 DOI: 10.1016/j.drudis.2013.12.005] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Revised: 10/31/2013] [Accepted: 12/11/2013] [Indexed: 02/06/2023]
Abstract
G protein-coupled receptor 55 (GPR55) is a putative cannabinoid receptor that is expressed in several tissues involved in regulating energy homeostasis, including the hypothalamus, gastrointestinal tract, pancreas, liver, white adipose and skeletal muscle. GPR55 has been shown to have a role in cancer and gastrointestinal inflammation, as well as in obesity and type 2 diabetes mellitus (T2DM). Despite this, the (patho)physiological role of GPR55 in cell dysfunction is still poorly understood, largely because of the limited identification of downstream signalling targets. Nonetheless, research has suggested that GPR55 modulation would be a useful pharmacological target in metabolically active tissues to improve treatment of diseases such as obesity and T2DM. Further research is essential to gain a better understanding of the role that this receptor might have in these and other pathophysiological conditions.
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Affiliation(s)
- Anna C Simcocks
- Centre for Chronic Disease Prevention and Management, College of Health and Biomedicine, Victoria University, Melbourne 8001, VIC, Australia
| | - Lannie O'Keefe
- Centre for Chronic Disease Prevention and Management, College of Health and Biomedicine, Victoria University, Melbourne 8001, VIC, Australia
| | - Kayte A Jenkin
- Centre for Chronic Disease Prevention and Management, College of Health and Biomedicine, Victoria University, Melbourne 8001, VIC, Australia
| | - Michael L Mathai
- Centre for Chronic Disease Prevention and Management, College of Health and Biomedicine, Victoria University, Melbourne 8001, VIC, Australia; The Florey Institute for Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC, Australia
| | - Deanne H Hryciw
- Department of Physiology, The University of Melbourne, Melbourne 3010, VIC, Australia
| | - Andrew J McAinch
- Centre for Chronic Disease Prevention and Management, College of Health and Biomedicine, Victoria University, Melbourne 8001, VIC, Australia.
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68
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Kotsikorou E, Sharir H, Shore DM, Hurst DP, Lynch DL, Madrigal KE, Heynen-Genel S, Milan LB, Chung TDY, Seltzman HH, Bai Y, Caron MG, Barak LS, Croatt MP, Abood ME, Reggio PH. Identification of the GPR55 antagonist binding site using a novel set of high-potency GPR55 selective ligands. Biochemistry 2013; 52:9456-69. [PMID: 24274581 DOI: 10.1021/bi4008885] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
GPR55 is a class A G protein-coupled receptor (GPCR) that has been implicated in inflammatory pain, neuropathic pain, metabolic disorder, bone development, and cancer. Initially deorphanized as a cannabinoid receptor, GPR55 has been shown to be activated by non-cannabinoid ligands such as l-α-lysophosphatidylinositol (LPI). While there is a growing body of evidence of physiological and pathophysiological roles for GPR55, the paucity of specific antagonists has limited its study. In collaboration with the Molecular Libraries Probe Production Centers Network initiative, we identified a series of GPR55 antagonists using a β-arrestin, high-throughput, high-content screen of ~300000 compounds. This screen yielded novel, GPR55 antagonist chemotypes with IC50 values in the range of 0.16-2.72 μM [Heynen-Genel, S., et al. (2010) Screening for Selective Ligands for GPR55: Antagonists (ML191, ML192, ML193) (Bookshelf ID NBK66153; PMID entry 22091481)]. Importantly, many of the GPR55 antagonists were completely selective, with no agonism or antagonism against GPR35, CB1, or CB2 up to 20 μM. Using a model of the GPR55 inactive state, we studied the binding of an antagonist series that emerged from this screen. These studies suggest that GPR55 antagonists possess a head region that occupies a horizontal binding pocket extending into the extracellular loop region, a central ligand portion that fits vertically in the receptor binding pocket and terminates with a pendant aromatic or heterocyclic ring that juts out. Both the region that extends extracellularly and the pendant ring are features associated with antagonism. Taken together, our results provide a set of design rules for the development of second-generation GPR55 selective antagonists.
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Affiliation(s)
- Evangelia Kotsikorou
- Department of Chemistry, University of Texas-Pan American , Edinburg, Texas 78539, United States
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69
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Paul RK, Wnorowski A, Gonzalez-Mariscal I, Nayak SK, Pajak K, Moaddel R, Indig FE, Bernier M, Wainer IW. (R,R')-4'-methoxy-1-naphthylfenoterol targets GPR55-mediated ligand internalization and impairs cancer cell motility. Biochem Pharmacol 2013; 87:547-61. [PMID: 24355564 DOI: 10.1016/j.bcp.2013.11.020] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Revised: 11/21/2013] [Accepted: 11/25/2013] [Indexed: 12/13/2022]
Abstract
(R,R')-4'-Methoxy-1-naphthylfenoterol (MNF) promotes growth inhibition and apoptosis of human HepG2 hepatocarcinoma cells via cannabinoid receptor (CBR) activation. The synthetic CB1R inverse agonist, AM251, has been shown to block the anti-mitogenic effect of MNF in these cells; however, AM251 is also an agonist of the recently deorphanized, lipid-sensing receptor, GPR55, whose upregulation contributes to carcinogenesis. Here, we investigated the role of MNF in GPR55 signaling in human HepG2 and PANC-1 cancer cell lines in culture by focusing first on internalization of the fluorescent ligand Tocrifluor 1117 (T1117). Initial results indicated that cell pretreatment with GPR55 agonists, including the atypical cannabinoid O-1602 and l-α-lysophosphatidylinositol, dose-dependently reduced the rate of cellular T1117 uptake, a process that was sensitive to MNF inhibition. GPR55 internalization and signaling mediated by O-1602 was blocked by MNF in GPR55-expressing HEK293 cells. Pretreatment of HepG2 and PANC-1 cells with MNF significantly abrogated the induction of ERK1/2 phosphorylation in response to AM251 and O-1602. Moreover, MNF exerted a coordinated negative regulation of AM251 and O-1602 inducible processes, including changes in cellular morphology and cell migration using scratch wound healing assay. This study shows for the first time that MNF impairs GPR55-mediated signaling and, therefore, may have therapeutic potential in the management of cancer.
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Affiliation(s)
- Rajib K Paul
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health (NIH), Baltimore, MD 21224, USA.
| | - Artur Wnorowski
- Laboratory of Medicinal Chemistry and Neuroengineering, Department of Chemistry, Medical University of Lublin, 20-093 Lublin, Poland.
| | - Isabel Gonzalez-Mariscal
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health (NIH), Baltimore, MD 21224, USA.
| | | | - Karolina Pajak
- Laboratory of Medicinal Chemistry and Neuroengineering, Department of Chemistry, Medical University of Lublin, 20-093 Lublin, Poland.
| | - Ruin Moaddel
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health (NIH), Baltimore, MD 21224, USA.
| | - Fred E Indig
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health (NIH), Baltimore, MD 21224, USA.
| | - Michel Bernier
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health (NIH), Baltimore, MD 21224, USA.
| | - Irving W Wainer
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health (NIH), Baltimore, MD 21224, USA.
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Abstract
G-protein–coupled receptors (GPCRs) still offer enormous scope for new therapeutic targets. Currently marketed agents are dominated by those with activity at aminergic receptors and yet they account for only ~10% of the family. Progress up until now with other subfamilies, notably orphans, Family A/peptide, Family A/lipid, Family B, Family C, and Family F, has been, at best, patchy. This may be attributable to the heterogeneous nature of GPCRs, their endogenous ligands, and consequently their binding sites. Our appreciation of receptor similarity has arguably been too simplistic, and screening collections have not necessarily been well suited to identifying leads in new areas. Despite the relative shortage of high-quality tool molecules in a number of cases, there is an emerging, and increasingly substantial, body of evidence associating many as yet “undrugged” receptors with a very wide range of diseases. Significant advances in our understanding of receptor pharmacology and technical advances in screening, protein X-ray crystallography, and ligand design methods are paving the way for new successes in the area. Exploitation of allosteric mechanisms; alternative signaling pathways such as G12/13, Gβγ, and β-arrestin; the discovery of “biased” ligands; and the emergence of GPCR-protein complexes as potential drug targets offer scope for new and much improved drugs.
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71
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Leyva-Illades D, Demorrow S. Orphan G protein receptor GPR55 as an emerging target in cancer therapy and management. Cancer Manag Res 2013; 5:147-55. [PMID: 23869178 PMCID: PMC3706254 DOI: 10.2147/cmar.s35175] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
G protein-coupled receptors (GPCRs) modulate a vast array of cellular processes. The current review gives an overview of the general characteristics of GPCRs and their role in physiological conditions. In addition, it describes the current knowledge of the physiological and pathophysiological functions of GPR55, an orphan GPCR, and how it can be exploited as a therapeutic target to combat various cancers.
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Affiliation(s)
- Dinorah Leyva-Illades
- Digestive Disease Research Center, Scott and White Hospital, Temple, TX, USA ; Department of Internal MedicineTexas A&M Health Science Center, Temple, TX, USA ; Research Service, Central Texas Veterans Health Care System, Temple, TX, USA
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72
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Kargl J, Brown AJ, Andersen L, Dorn G, Schicho R, Waldhoer M, Heinemann A. A selective antagonist reveals a potential role of G protein-coupled receptor 55 in platelet and endothelial cell function. J Pharmacol Exp Ther 2013; 346:54-66. [PMID: 23639801 DOI: 10.1124/jpet.113.204180] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The G protein-coupled receptor 55 (GPR55) is a lysophosphatidylinositol (LPI) receptor that is also responsive to certain cannabinoids. Although GPR55 has been implicated in several (patho)physiologic functions, its role remains enigmatic owing mainly to the lack of selective GPR55 antagonists. Here we show that the compound CID16020046 ((4-[4-(3-hydroxyphenyl)-3-(4-methylphenyl)-6-oxo-1H,4H,5H,6H-pyrrolo[3,4-c]pyrazol-5-yl] benzoic acid) is a selective GPR55 antagonist. In yeast cells expressing human GPR55, CID16020046 antagonized agonist-induced receptor activation. In human embryonic kidney (HEK293) cells stably expressing human GPR55, the compound behaved as an antagonist on LPI-mediated Ca²⁺ release and extracellular signal-regulated kinases activation, but not in HEK293 cells expressing cannabinoid receptor 1 or 2 (CB₁ or CB₂). CID16020046 concentration dependently inhibited LPI-induced activation of nuclear factor of activated T-cells (NFAT), nuclear factor κ of activated B cells (NF-κB) and serum response element, translocation of NFAT and NF-κB, and GPR55 internalization. It reduced LPI-induced wound healing in primary human lung microvascular endothelial cells and reversed LPI-inhibited platelet aggregation, suggesting a novel role for GPR55 in platelet and endothelial cell function. CID16020046 is therefore a valuable tool to study GPR55-mediated mechanisms in primary cells and tissues.
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Affiliation(s)
- Julia Kargl
- Institute for Experimental and Clinical Pharmacology, Medical University of Graz, 8010 Graz, Austria.
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73
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The endocannabinoid signaling system in cancer. Trends Pharmacol Sci 2013; 34:273-82. [PMID: 23602129 DOI: 10.1016/j.tips.2013.03.003] [Citation(s) in RCA: 131] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Revised: 03/07/2013] [Accepted: 03/12/2013] [Indexed: 12/21/2022]
Abstract
Changes in lipid metabolism are intimately related to cancer. Several classes of bioactive lipids play roles in the regulation of signaling pathways involved in neoplastic transformation and tumor growth and progression. The endocannabinoid system, comprising lipid-derived endocannabinoids, their G-protein-coupled receptors (GPCRs), and the enzymes for their metabolism, is emerging as a promising therapeutic target in cancer. This report highlights the main signaling pathways for the antitumor effects of the endocannabinoid system in cancer and its basic role in cancer pathogenesis, and discusses the alternative view of cannabinoid receptors as tumor promoters. We focus on new players in the antitumor action of the endocannabinoid system and on emerging crosstalk among cannabinoid receptors and other membrane or nuclear receptors involved in cancer. We also discuss the enzyme MAGL, a key player in endocannabinoid metabolism that was recently recognized as a marker of tumor lipogenic phenotype.
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74
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Wu CS, Chen H, Sun H, Zhu J, Jew CP, Wager-Miller J, Straiker A, Spencer C, Bradshaw H, Mackie K, Lu HC. GPR55, a G-protein coupled receptor for lysophosphatidylinositol, plays a role in motor coordination. PLoS One 2013; 8:e60314. [PMID: 23565223 PMCID: PMC3614963 DOI: 10.1371/journal.pone.0060314] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Accepted: 02/25/2013] [Indexed: 12/15/2022] Open
Abstract
The G-protein coupled receptor 55 (GPR55) is activated by lysophosphatidylinositols and some cannabinoids. Recent studies found prominent roles for GPR55 in neuropathic/inflammatory pain, cancer and bone physiology. However, little is known about the role of GPR55 in CNS development and function. To address this question, we performed a detailed characterization of GPR55 knockout mice using molecular, anatomical, electrophysiological, and behavioral assays. Quantitative PCR studies found that GPR55 mRNA was expressed (in order of decreasing abundance) in the striatum, hippocampus, forebrain, cortex, and cerebellum. GPR55 deficiency did not affect the concentrations of endocannabinoids and related lipids or mRNA levels for several components of the endocannabinoid system in the hippocampus. Normal synaptic transmission and short-term as well as long-term synaptic plasticity were found in GPR55 knockout CA1 pyramidal neurons. Deleting GPR55 function did not affect behavioral assays assessing muscle strength, gross motor skills, sensory-motor integration, motor learning, anxiety or depressive behaviors. In addition, GPR55 null mutant mice exhibited normal contextual and auditory-cue conditioned fear learning and memory in a Pavlovian conditioned fear test. In contrast, when presented with tasks requiring more challenging motor responses, GPR55 knockout mice showed impaired movement coordination. Taken together, these results suggest that GPR55 plays a role in motor coordination, but does not strongly regulate CNS development, gross motor movement or several types of learned behavior.
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Affiliation(s)
- Chia-Shan Wu
- The Cain Foundation Laboratories, Baylor College of Medicine, Houston, Texas, United States of America
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Hongmei Chen
- The Cain Foundation Laboratories, Baylor College of Medicine, Houston, Texas, United States of America
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Hao Sun
- The Cain Foundation Laboratories, Baylor College of Medicine, Houston, Texas, United States of America
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Jie Zhu
- The Cain Foundation Laboratories, Baylor College of Medicine, Houston, Texas, United States of America
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Chris P. Jew
- The Cain Foundation Laboratories, Baylor College of Medicine, Houston, Texas, United States of America
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas, United States of America
| | - James Wager-Miller
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana, United States of America
| | - Alex Straiker
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana, United States of America
| | - Corinne Spencer
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Heather Bradshaw
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana, United States of America
| | - Ken Mackie
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana, United States of America
| | - Hui-Chen Lu
- The Cain Foundation Laboratories, Baylor College of Medicine, Houston, Texas, United States of America
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas, United States of America
- Program in Developmental Biology, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas, United States of America
- * E-mail:
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75
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Alonso V, Friedman PA. Minireview: ubiquitination-regulated G protein-coupled receptor signaling and trafficking. Mol Endocrinol 2013; 27:558-72. [PMID: 23471539 DOI: 10.1210/me.2012-1404] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
G protein-coupled receptors (GPCRs) are the largest and most diverse superfamily of membrane proteins and mediate most cellular responses to hormones and neurotransmitters. Posttranslational modifications are considered the main regulators of all GPCRs. In addition to phosphorylation, glycosylation, and palmitoylation, increasing evidence as reviewed here reveals that ubiquitination also regulates the magnitude and temporospatial aspects of GPCR signaling. Posttranslational protein modification by ubiquitin is a key molecular mechanism governing proteins degradation. Ubiquitination mediates the covalent conjugation of ubiquitin, a highly conserved polypeptide of 76 amino acids, to protein substrates. This process is catalyzed by 3 enzymes acting in tandem: an E1, ubiquitin-activating enzyme; an E2, ubiquitin-carrying enzyme; and an E3, ubiquitin ligase. Ubiquitination is counteracted by deubiquitinating enzymes that deconjugate ubiquitin-modified proteins and rescue the substrate from proteasomal degradation. Although ubiquitination is known to target many GPCRs for lysosomal or proteasomal degradation, emerging findings define novel roles for the basal status of ubiquitination and for rapid deubiquitination and transubiquitination controlling cell surface expression and cellular responsiveness of some GPCRs. In this review, we highlight the classical and novel roles of ubiquitin in the regulation of GPCR function, signaling, and trafficking.
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Affiliation(s)
- Verónica Alonso
- Institute of Applied Molecular Medicine, San Pablo-CEU University School of Medicine, Madrid, 28668, Spain
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