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Nussinov R, Zhang W, Liu Y, Jang H. Mitogen signaling strength and duration can control cell cycle decisions. SCIENCE ADVANCES 2024; 10:eadm9211. [PMID: 38968359 DOI: 10.1126/sciadv.adm9211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Accepted: 05/31/2024] [Indexed: 07/07/2024]
Abstract
Decades ago, mitogen-promoted signaling duration and strength were observed to be sensed by the cell and to be critical for its decisions: to proliferate or differentiate. Landmark publications established the importance of mitogen signaling not only in the G1 cell cycle phase but also through the S and the G2/M transition. Despite these early milestones, how mitogen signal duration and strength, short and strong or weaker and sustained, control cell fate has been largely unheeded. Here, we center on cardinal signaling-related questions, including (i) how fluctuating mitogenic signals are converted into cell proliferation-differentiation decisions and (ii) why extended duration of weak signaling is associated with differentiation, while bursts of strong and short induce proliferation but, if too strong and long, induce irreversible senescence. Our innovative broad outlook harnesses cell biology and protein conformational ensembles, helping us to define signaling strength, clarify cell cycle decisions, and thus cell fate.
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Affiliation(s)
- Ruth Nussinov
- Computational Structural Biology Section, Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA
- Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
- Cancer Innovation Laboratory, National Cancer Institute, Frederick, MD 21702, USA
| | - Wengang Zhang
- Cancer Innovation Laboratory, National Cancer Institute, Frederick, MD 21702, USA
| | - Yonglan Liu
- Cancer Innovation Laboratory, National Cancer Institute, Frederick, MD 21702, USA
| | - Hyunbum Jang
- Computational Structural Biology Section, Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA
- Cancer Innovation Laboratory, National Cancer Institute, Frederick, MD 21702, USA
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Tang Z, Tang N, Jiang S, Bai Y, Guan C, Zhang W, Fan S, Huang Y, Lin H, Ying Y. The Chemosensitizing Role of Metformin in Anti-Cancer Therapy. Anticancer Agents Med Chem 2021; 21:949-962. [PMID: 32951587 DOI: 10.2174/1871520620666200918102642] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 07/23/2020] [Accepted: 08/08/2020] [Indexed: 11/22/2022]
Abstract
Chemoresistance, which leads to the failure of chemotherapy and further tumor recurrence, presents the largest hurdle for the success of anti-cancer therapy. In recent years, metformin, a widely used first-line antidiabetic drug, has attracted increasing attention for its anti-cancer effects. A growing body of evidence indicates that metformin can sensitize tumor responses to different chemotherapeutic drugs, such as hormone modulating drugs, anti-metabolite drugs, antibiotics, and DNA-damaging drugs via selective targeting of Cancer Stem Cells (CSCs), improving the hypoxic microenvironment, and by suppressing tumor metastasis and inflammation. In addition, metformin may regulate metabolic programming, induce apoptosis, reverse Epithelial to Mesenchymal Transition (EMT), and Multidrug Resistance (MDR). In this review, we summarize the chemosensitization effects of metformin and focus primarily on its molecular mechanisms in enhancing the sensitivity of multiple chemotherapeutic drugs, through targeting of mTOR, ERK/P70S6K, NF-κB/HIF-1 α, and Mitogen- Activated Protein Kinase (MAPK) signaling pathways, as well as by down-regulating the expression of CSC genes and Pyruvate Kinase isoenzyme M2 (PKM2). Through a comprehensive understanding of the molecular mechanisms of chemosensitization provided in this review, the rationale for the use of metformin in clinical combination medications can be more systematically and thoroughly explored for wider adoption against numerous cancer types.>.
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Affiliation(s)
- Zhimin Tang
- Jiangxi Province Key Laboratory of Tumor Pathogens and Molecular Pathology and Department of Pathophysiology, Schools of Basic Medical Sciences, Nanchang University, Nanchang 330006, China
| | - Nan Tang
- Nanchang Joint Program, Queen Mary School, Nanchang University, Nanchang 330006, China
| | - Shanshan Jiang
- Institute of Hematological Research, Shanxi Provincial People's Hospital, Xian 710000, China
| | - Yangjinming Bai
- Nanchang Joint Program, Queen Mary School, Nanchang University, Nanchang 330006, China
| | - Chenxi Guan
- Jiangxi Province Key Laboratory of Tumor Pathogens and Molecular Pathology and Department of Pathophysiology, Schools of Basic Medical Sciences, Nanchang University, Nanchang 330006, China
| | - Wansi Zhang
- Jiangxi Province Key Laboratory of Tumor Pathogens and Molecular Pathology and Department of Pathophysiology, Schools of Basic Medical Sciences, Nanchang University, Nanchang 330006, China
| | - Shipan Fan
- Guangzhou Regenerative Medicine and Health Guangdong Laboratory (GRMH-GDL), Guangzhou 510005, China
| | - Yonghong Huang
- Jiangxi Province Key Laboratory of Tumor Pathogens and Molecular Pathology and Department of Pathophysiology, Schools of Basic Medical Sciences, Nanchang University, Nanchang 330006, China
| | - Hui Lin
- Jiangxi Province Key Laboratory of Tumor Pathogens and Molecular Pathology and Department of Pathophysiology, Schools of Basic Medical Sciences, Nanchang University, Nanchang 330006, China
| | - Ying Ying
- Jiangxi Province Key Laboratory of Tumor Pathogens and Molecular Pathology and Department of Pathophysiology, Schools of Basic Medical Sciences, Nanchang University, Nanchang 330006, China
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Digiacomo G, Fumarola C, La Monica S, Bonelli MA, Cretella D, Alfieri R, Cavazzoni A, Galetti M, Bertolini P, Missale G, Petronini PG. Simultaneous Combination of the CDK4/6 Inhibitor Palbociclib With Regorafenib Induces Enhanced Anti-tumor Effects in Hepatocarcinoma Cell Lines. Front Oncol 2020; 10:563249. [PMID: 33072590 PMCID: PMC7539564 DOI: 10.3389/fonc.2020.563249] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 08/20/2020] [Indexed: 12/28/2022] Open
Abstract
Advanced hepatocarcinoma (HCC) is an aggressive malignancy with poor prognosis and limited treatment options. Alterations of the cyclin D-CDK4/6-Rb pathway occur frequently in HCC, providing the rationale for its targeting at least in a molecular subset of HCC. In a panel of HCC cell lines, we investigated whether the CDK4/6 inhibitor palbociclib might improve the efficacy of regorafenib, a powerful multi-kinase inhibitor approved as second-line treatment for advanced HCC after sorafenib failure and currently under clinical investigation as first-line therapy in combination with immunotherapy. In Rb-proficient cells, the simultaneous drug combination, but not the sequential schedules, inhibited cell proliferation, either in short or in long-term experiments, and induced cell death more strongly than individual treatments. Moreover, the combination significantly reduced spheroid cell growth and inhibited cell migration/invasion. The superior efficacy of palbociclib plus regorafenib emerged also under hypoxia and was associated with a significant down-regulation of CDK4/6-Rb-myc and mTORC1/p70S6K signaling. Moreover, regorafenib suppressed palbociclib-induced expression of cyclin D1 contributing to the cytotoxic effects of the combination. Besides these inhibitory effects on cell viability/proliferation, palbociclib and regorafenib reduced glucose uptake, although this effect was dependent on the cell model and on the oxygen availability (normoxia or hypoxia). Palbociclib and regorafenib combination impaired glucose uptake and utilization, down-regulating basal and hypoxia-induced expression of HIF-1α, HIF-2α, GLUT-1, and MCT4 proteins as well as the activity/expression of glycolytic enzymes (HK2, PFKP, aldolase A, PKM2). In addition, regorafenib alone reduced mitochondrial respiration. The combined treatment impaired glucose metabolism and respiration without enhancing the effects of the single agents. Our findings provide pre-clinical evidence for the effectiveness of palbociclib and regorafenib combination in HCC cell models.
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Affiliation(s)
| | - Claudia Fumarola
- Department of Medicine and Surgery, University of Parma, Parma, Italy
| | - Silvia La Monica
- Department of Medicine and Surgery, University of Parma, Parma, Italy
| | - Mara A Bonelli
- Department of Medicine and Surgery, University of Parma, Parma, Italy
| | - Daniele Cretella
- Department of Medicine and Surgery, University of Parma, Parma, Italy
| | - Roberta Alfieri
- Department of Medicine and Surgery, University of Parma, Parma, Italy
| | - Andrea Cavazzoni
- Department of Medicine and Surgery, University of Parma, Parma, Italy
| | - Maricla Galetti
- Istituto Nazionale per l'Assicurazione contro gli Infortuni sul Lavoro (INAIL) Research, Department of Occupational and Environmental Medicine, Epidemiology and Hygiene, Rome, Italy
| | - Patrizia Bertolini
- Paediatric Hematology Oncology Unit, University Hospital of Parma, Parma, Italy
| | - Gabriele Missale
- Department of Medicine and Surgery, University of Parma, Parma, Italy.,Unit of Infectious Diseases and Hepatology, University Hospital of Parma, Parma, Italy
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Wang P, Ma M, Zhang S. EGF-induced urokinase plasminogen activator receptor promotes epithelial to mesenchymal transition in human gastric cancer cells. Oncol Rep 2017; 38:2325-2334. [PMID: 28849196 DOI: 10.3892/or.2017.5920] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 08/10/2017] [Indexed: 11/05/2022] Open
Abstract
Epidermal growth factor (EGF) signaling has been shown to induce epithelial to mesenchymal transition (EMT) in many types of cancer cells. However, the molecular mechanism of EGF-induced EMT in gastric cancer remains largely unknown. In the present study, we found that human gastric cancer cell lines SGC-7901 and BGC-823 underwent EMT phenotypic changes upon exposure to EGF. The induction of EMT was consistent with aggressive characteristics such as increased cell migration, invasion and clonogenic growth. Additionally, EGF stimulation also led to the upregulation of urokinase plasminogen activator receptor (uPAR) both at mRNA and protein levels. Knockdown of uPAR by siRNA significantly attenuated EMT induction by EGF in SGC-7901 and BGC-823 cells. Furthermore, EGF increased ERK1/2 activity and blocking ERK1/2 signaling with its inhibitor, U0126, markedly inhibited EGF-induced uPAR expression and consequently EMT. Collectively, the present study demonstrated that EGF induced aggressiveness of gastric cancer cells by activating EMT, which involved the activation of the ERK1/2 pathway and, subsequently, uPAR expression.
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Affiliation(s)
- Pingping Wang
- Department of Clinical Laboratory, Taizhou Second People's Hospital, Taizhou, Jiangsu 225599, P.R. China
| | - Maoyuan Ma
- Department of Gastroenterology, Taizhou Second People's Hospital, Taizhou, Jiangsu 225599, P.R. China
| | - Shanhui Zhang
- Department of Clinical Laboratory, Taizhou Second People's Hospital, Taizhou, Jiangsu 225599, P.R. China
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Zanda MT, Fadda P, Antinori S, Di Chio M, Fratta W, Chiamulera C, Fattore L. Methoxetamine affects brain processing involved in emotional response in rats. Br J Pharmacol 2017; 174:3333-3345. [PMID: 28718892 DOI: 10.1111/bph.13952] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 06/30/2017] [Accepted: 07/06/2017] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND AND PURPOSE Methoxetamine (MXE) is a novel psychoactive substance that is emerging on the Internet and induces dissociative effects and acute toxicity. Its pharmacological effects have not yet been adequately investigated. EXPERIMENTAL APPROACH We examined a range of behavioural effects induced by acute administration of MXE (0.5-5 mg·kg-1 ; i.p.) in rats and whether it causes rapid neuroadaptive molecular changes. KEY RESULTS MXE (0.5-5 mg·kg-1 ) affected motor activity in a dose- and time-dependent manner, inducing hypermotility and hypomotility at low and high doses respectively. At low and intermediate doses (0.5 and 1 mg·kg-1 ), MXE induced anxious and/or obsessive-compulsive traits (marble burying test), did not significantly increase sociability (social interaction test) or induce spatial anxiety (elevated plus maze test). At a high dose (5 mg·kg-1 ), MXE induced transient analgesia (tail-flick and hot-plate test), decreased social interaction time (social interaction test) and reduced immobility time while increasing swimming activity (forced swim test), suggesting an antidepressant effect. Acute MXE administration did not affect self-grooming behaviour at any dose tested. Immunohistochemical analysis showed that behaviourally active doses of MXE (1 and 5 mg·kg-1 ) increased phosphorylation of ribosomal protein S6 in the medial prefrontal cortex and hippocampus. CONCLUSIONS AND IMPLICATIONS MXE differentially affected motor activity, behaviour and emotional states in rats, depending on the dose tested. As reported for ketamine, phosphorylation of the ribosomal protein S6 was increased in MXE-treated animals, thus providing a 'molecular snapshot' of rapid neuroadaptive molecular changes induced by behaviourally active doses of MXE.
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Affiliation(s)
- M T Zanda
- Department of Biomedical Sciences, Division of Neuroscience and Clinical Pharmacology, University of Cagliari, Cagliari, Italy
| | - P Fadda
- Department of Biomedical Sciences, Division of Neuroscience and Clinical Pharmacology, University of Cagliari, Cagliari, Italy
| | - S Antinori
- Department of Biomedical Sciences, Division of Neuroscience and Clinical Pharmacology, University of Cagliari, Cagliari, Italy
| | - M Di Chio
- Department of Diagnostic and Public Health, Section of Pharmacology, University of Verona, Verona, Italy
| | - W Fratta
- Department of Biomedical Sciences, Division of Neuroscience and Clinical Pharmacology, University of Cagliari, Cagliari, Italy
| | - C Chiamulera
- Department of Diagnostic and Public Health, Section of Pharmacology, University of Verona, Verona, Italy
| | - L Fattore
- Institute of Neuroscience (IN-CNR), National Research Council of Italy, Cagliari, Italy
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Mechanisms of action of sacubitril/valsartan on cardiac remodeling: a systems biology approach. NPJ Syst Biol Appl 2017. [PMID: 28649439 PMCID: PMC5460292 DOI: 10.1038/s41540-017-0013-4] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Sacubitril/Valsartan, proved superiority over other conventional heart failure management treatments, but its mechanisms of action remains obscure. In this study, we sought to explore the mechanistic details for Sacubitril/Valsartan in heart failure and post-myocardial infarction remodeling, using an in silico, systems biology approach. Myocardial transcriptome obtained in response to myocardial infarction in swine was analyzed to address post-infarction ventricular remodeling. Swine transcriptome hits were mapped to their human equivalents using Reciprocal Best (blast) Hits, Gene Name Correspondence, and InParanoid database. Heart failure remodeling was studied using public data available in gene expression omnibus (accession GSE57345, subseries GSE57338), processed using the GEO2R tool. Using the Therapeutic Performance Mapping System technology, dedicated mathematical models trained to fit a set of molecular criteria, defining both pathologies and including all the information available on Sacubitril/Valsartan, were generated. All relationships incorporated into the biological network were drawn from public resources (including KEGG, REACTOME, INTACT, BIOGRID, and MINT). An artificial neural network analysis revealed that Sacubitril/Valsartan acts synergistically against cardiomyocyte cell death and left ventricular extracellular matrix remodeling via eight principal synergistic nodes. When studying each pathway independently, Valsartan was found to improve cardiac remodeling by inhibiting members of the guanine nucleotide-binding protein family, while Sacubitril attenuated cardiomyocyte cell death, hypertrophy, and impaired myocyte contractility by inhibiting PTEN. The complex molecular mechanisms of action of Sacubitril/Valsartan upon post-myocardial infarction and heart failure cardiac remodeling were delineated using a systems biology approach. Further, this dataset provides pathophysiological rationale for the use of Sacubitril/Valsartan to prevent post-infarct remodeling. The new wonder drug in heart failure management, Sacubitril/Valsartan, rejuvenates the heart by preventing its dilation. Using data from myocardial infarction and heart failure samples, we generated a mathematical model to better understand how Sacubitril/Valsartan modulates pathological heart resize and the combined effect of the drug. Our analysis revealed that Sacubitril/Valsartan mainly acts by blocking both, cell death and the pathological makeover of the outer-membrane of the cardiac cells. These two major processes occur after a heart attack. Most importantly, we discovered a core of 8 proteins that emerge as key players in this process. A better understanding of the mechanism of novel cardiovascular drugs at the most basic level may help decipher future therapies and indications.
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Chai X, Chu H, Yang X, Meng Y, Shi P, Gou S. Metformin Increases Sensitivity of Pancreatic Cancer Cells to Gemcitabine by Reducing CD133+ Cell Populations and Suppressing ERK/P70S6K Signaling. Sci Rep 2015; 5:14404. [PMID: 26391180 PMCID: PMC4585731 DOI: 10.1038/srep14404] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Accepted: 08/26/2015] [Indexed: 12/14/2022] Open
Abstract
The prognosis of pancreatic cancer remains dismal, with little advance in chemotherapy because of its high frequency of chemoresistance. Metformin is widely used to treat type II diabetes, and was shown recently to inhibit pancreatic cancer stem cell proliferation. In the present study, we investigated the role of metformin in chemoresistance of pancreatic cancer cells to gemcitabine, and its possible cellular and molecular mechanisms. Metformin increases sensitivity of pancreatic cancer cells to gemcitabine. The mechanism involves, at least in part, the inhibition of CD133+ cells proliferation and suppression of P70S6K signaling activation via inhibition of ERK phosphorylation. Studies of primary tumor samples revealed a relationship between P70S6K signaling activation and the malignancy of pancreatic cancer. Analysis of clinical data revealed a trend of the benefit of metformin for pancreatic cancer patients with diabetes. The results suggested that metformin has a potential clinical use in overcoming chemoresistance of pancreatic cancer.
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Affiliation(s)
- Xinqun Chai
- Department of Hepatobiliary Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology
| | - Hongpeng Chu
- Department of Hepatobiliary Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology
| | - Xuan Yang
- Department of Hepatobiliary Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology
| | - Yuanpu Meng
- Department of Hepatobiliary Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology
| | - Pengfei Shi
- Department of Breast and Thyroid Surgery, Central Hospital of Wuhan
| | - Shanmiao Gou
- Pancreatic Disease Institute, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology
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Bomo J, Ezan F, Tiaho F, Bellamri M, Langouët S, Theret N, Baffet G. Increasing 3D Matrix Rigidity Strengthens Proliferation and Spheroid Development of Human Liver Cells in a Constant Growth Factor Environment. J Cell Biochem 2015; 117:708-20. [PMID: 26331987 DOI: 10.1002/jcb.25356] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Accepted: 08/28/2015] [Indexed: 12/20/2022]
Abstract
Mechanical forces influence the growth and shape of virtually all tissues and organs. Recent studies show that increased cell contractibility, growth and differentiation might be normalized by modulating cell tensions. Particularly, the role of these tensions applied by the extracellular matrix during liver fibrosis could influence the hepatocarcinogenesis process. The objective of this study is to determine if 3D stiffness could influence growth and phenotype of normal and transformed hepatocytes and to integrate extracellular matrix (ECM) stiffness to tensional homeostasis. We have developed an appropriate 3D culture model: hepatic cells within three-dimensional collagen matrices with varying rigidity. Our results demonstrate that the rigidity influenced the cell phenotype and induced spheroid clusters development whereas in soft matrices, Huh7 transformed cells were less proliferative, well-spread and flattened. We confirmed that ERK1 played a predominant role over ERK2 in cisplatin-induced death, whereas ERK2 mainly controlled proliferation. As compared to 2D culture, 3D cultures are associated with epithelial markers expression. Interestingly, proliferation of normal hepatocytes was also induced in rigid gels. Furthermore, biotransformation activities are increased in 3D gels, where CYP1A2 enzyme can be highly induced/activated in primary culture of human hepatocytes embedded in the matrix. In conclusion, we demonstrated that increasing 3D rigidity could promote proliferation and spheroid developments of liver cells demonstrating that 3D collagen gels are an attractive tool for studying rigidity-dependent homeostasis of the liver cells embedded in the matrix and should be privileged for both chronic toxicological and pharmacological drug screening.
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Affiliation(s)
- Jérémy Bomo
- Institut National de la Santé et de la Recherche Médicale (Inserm), UMR1085 Institut de Recherche sur la Santé l'Environnement et le Travail (IRSET); University of Rennes 1, SFR Biosit, F-35043, Rennes, France
| | - Frédéric Ezan
- Institut National de la Santé et de la Recherche Médicale (Inserm), UMR1085 Institut de Recherche sur la Santé l'Environnement et le Travail (IRSET); University of Rennes 1, SFR Biosit, F-35043, Rennes, France
| | - François Tiaho
- Institut National de la Santé et de la Recherche Médicale (Inserm), UMR1085 Institut de Recherche sur la Santé l'Environnement et le Travail (IRSET); University of Rennes 1, SFR Biosit, F-35043, Rennes, France
| | - Medjda Bellamri
- Institut National de la Santé et de la Recherche Médicale (Inserm), UMR1085 Institut de Recherche sur la Santé l'Environnement et le Travail (IRSET); University of Rennes 1, SFR Biosit, F-35043, Rennes, France
| | - Sophie Langouët
- Institut National de la Santé et de la Recherche Médicale (Inserm), UMR1085 Institut de Recherche sur la Santé l'Environnement et le Travail (IRSET); University of Rennes 1, SFR Biosit, F-35043, Rennes, France
| | - Nathalie Theret
- Institut National de la Santé et de la Recherche Médicale (Inserm), UMR1085 Institut de Recherche sur la Santé l'Environnement et le Travail (IRSET); University of Rennes 1, SFR Biosit, F-35043, Rennes, France
| | - Georges Baffet
- Institut National de la Santé et de la Recherche Médicale (Inserm), UMR1085 Institut de Recherche sur la Santé l'Environnement et le Travail (IRSET); University of Rennes 1, SFR Biosit, F-35043, Rennes, France
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Wen J, Zhao Y, Shen Y, Guo L. Effect of orexin A on apoptosis in BGC-823 gastric cancer cells via OX1R through the AKT signaling pathway. Mol Med Rep 2015; 11:3439-44. [PMID: 25586545 DOI: 10.3892/mmr.2015.3190] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2014] [Accepted: 07/22/2014] [Indexed: 01/16/2023] Open
Abstract
Orexins are a class of peptides involved in the regulation of food intake, energy homeostasis, the sleep‑wake cycle and gastrointestinal function. Recent studies have demonstrated that orexin A may influence apoptosis and proliferation in numerous types of cancer cells. However, the effect of orexin A on gastric cancer cells and its mechanisms of action remain elusive. In the present study, BGC‑823 gastric cancer cells were treated with orexin A (10‑10‑10‑6 M) in vitro and the expression levels of orexin receptor 1 (OX1R) protein in cells was then determined. The proliferation, viability and apoptosis of BGC‑823 cells were detected. In addition, BGC‑823 cells were treated with AKT inhibitor PF‑04691502 or OX1R‑specific antagonist SB334867 in combination with orexin A, in order to examine the activation of AKT and caspase‑3. The results showed that orexin A (10‑10‑10‑6 M) stimulated the OX1R protein expression in BGC‑823 cells, which improved the proliferation and viability of the cells as well as protected them from apoptosis. Phosphorylated AKT protein was significantly increased in BGC‑823 cells following treatment with orexin A. Moreover, 10‑8 M orexin A reduced the proapoptotic activity of caspase‑3 (by ≤30%). The OX1R antagonist SB334867 (10‑6 M) and AKT antagonist PF‑04691502 (10‑6 M), when used individually or in combination, abolished the effect of orexin A (10‑8 M) on BGC-823 cells. In conclusion, the results of the present study demonstrated that orexin A inhibited gastric cancer cell apoptosis via OX1R through the AKT signaling pathway.
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Affiliation(s)
- Jing Wen
- Department of Endocrinology, First Affiliated Hospital, China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Yuyan Zhao
- Department of Endocrinology, First Affiliated Hospital, China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Yang Shen
- Department of Endocrinology, First Affiliated Hospital, China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Lei Guo
- Department of Orthopedic Surgery, First Affiliated Hospital, China Medical University, Shenyang, Liaoning 110001, P.R. China
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Downregulation of galectin-3 causes a decrease in uPAR levels and inhibits the proliferation, migration and invasion of hepatocellular carcinoma cells. Oncol Rep 2014; 32:411-8. [PMID: 24807674 DOI: 10.3892/or.2014.3170] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Accepted: 04/04/2014] [Indexed: 11/05/2022] Open
Abstract
Hepatocellular carcinoma (HCC) is the third most common cause of cancer-related mortality worldwide. Galectin-3 (Gal-3), a multifunctional β-galactoside-binding protein, is highly expressed and associated with the prognosis of HCC. However, the functions of Gal-3 in HCC cells are not fully understood. To address the function of Gal-3 in HCC cells, we used small interfering RNA (siRNA) to knock down Gal-3 expression in HepG2, an HCC cell line. We found that in vitro the silencing of Gal-3 decreased the proliferative activity, colony formation ability, migratory and invasive potential of HepG2 cells. The silencing of Gal-3 significantly decreased the mRNA and protein levels of urokinase-type plasminogen activator receptor (uPAR) as well as uPAR's downstream signaling transduction pathway, including phosphorylation of AKT. Furthermore, the downregulation of Gal-3 by siRNA resulted in significantly decreased activity of the MEK/ERK signaling pathway, and the treatment of HepG2 cells with MEK/ERK inhibitor U0126 significantly reduced the mRNA and protein levels of uPAR. Taken together, our results suggest that Gal-3 modulates uPAR expression via the MEK/ERK pathway, and that Gal-3 may be a potential therapeutic target for the treatment of HCC.
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RANDLE DIANDRAD, CLARKE SHINEKA, HENDERSON VERONICA, ODERO-MARAH VALERIEA. Snail mediates invasion through uPA/uPAR and the MAPK signaling pathway in prostate cancer cells. Oncol Lett 2013; 6:1767-1773. [PMID: 26889270 PMCID: PMC4738196 DOI: 10.3892/ol.2013.1635] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Accepted: 09/17/2013] [Indexed: 01/17/2023] Open
Abstract
Epithelial-mesenchymal transition (EMT) is a process by which cancer cells acquire mesenchymal properties, such as induction of vimentin, while epithelial-associated genes like E-cadherin are lost. This enables cells to be more metastatic. Factors that are able to induce EMT include growth factors such as transforming growth factor-β (TGF-β) and epidermal growth factor, and transcription factors such as Snail. Snail-induced EMT promotes migration and invasion and we hypothesized that this may be mediated by the activity of urokinase-type plasminogen activator (uPA) and its receptor (uPAR). LNCaP, 22Rv1 and ARCaP human prostate cancer (CaP) cells stably transfected with empty vector control (Neo) or constitutively active Snail exhibited increased cell invasion. Superarray analysis revealed an upregulation in uPA and uPAR RNA expression in Snail-transfected ARCaP cells compared with that of a Neo control. In addition, the protein expression levels of Snail, uPA and uPAR were measured by western blot analysis which showed that overexpression of Snail increased uPA and uPAR protein levels. The activity of uPA in conditioned media was measured using an ELISA which revealed that uPA activity was elevated in LNCaP, 22Rv1 and ARCaP cells overexpressing Snail. Additionally, transient silencing of uPAR in ARCaP cells overexpressing Snail using short interfering RNA resulted in abrogation of Snail-mediated invasion. Snail overexpression was associated with increased extracellular-signal-regulated kinase activity, and antagonism of this activity with mitogen-activated protein (MAPK) inhibitor, UO126, inhibited cell invasion and decreased uPA activity. Therefore, Snail-mediated cell invasion in human CaP cells may occur via the regulation of uPA/uPAR and the MAPK signaling pathway.
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Affiliation(s)
- DIANDRA D. RANDLE
- Department of Biological Sciences, Center for Cancer Research and Therapeutic Development, Clark Atlanta University, Atlanta, GA 30314, USA
| | - SHINEKA CLARKE
- Department of Biological Sciences, Center for Cancer Research and Therapeutic Development, Clark Atlanta University, Atlanta, GA 30314, USA
| | - VERONICA HENDERSON
- Department of Biological Sciences, Center for Cancer Research and Therapeutic Development, Clark Atlanta University, Atlanta, GA 30314, USA
| | - VALERIE A. ODERO-MARAH
- Department of Biological Sciences, Center for Cancer Research and Therapeutic Development, Clark Atlanta University, Atlanta, GA 30314, USA
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Baicalein inhibits the invasion and metastatic capabilities of hepatocellular carcinoma cells via down-regulation of the ERK pathway. PLoS One 2013; 8:e72927. [PMID: 24039823 PMCID: PMC3765161 DOI: 10.1371/journal.pone.0072927] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Accepted: 07/15/2013] [Indexed: 01/13/2023] Open
Abstract
Baicalein, a widely used Chinese herbal medicine, has historically been used in anti-inflammatory and anti-cancer therapies. However, the anti-metastatic effect and molecular mechanism(s) of baicalein on hepatocellular carcinoma (HCC) remain poorly understood. Therefore, the purpose of this study was to assess the anti-metastatic effects of baicalein and related mechanism(s) on HCC. Based on assays utilized in both HCC cell lines and in an animal model, we found that baicalein inhibited tumor cell metastasis in vivo and in vitro. Furthermore, after treatment with baicalein for 24 hours, there was a decrease in the levels of matrix metalloproteinase-2 (MMP-2), MMP-9 and urokinase-type plasminogen activator (u-PA) expression as well as proteinase activity in hepatocellular carcinoma MHCC97H cells. Meanwhile, the expression of tissue inhibitor of metalloproteinase-1 (TIMP-1) and TIMP-2 were increased in a dose-dependent fashion. Moreover, baicalein treatment dramatically decreased the levels of the phosphorylated forms of MEK1 and ERK1/2. MEK1 overexpression partially blocked the anti-metastatic effects of baicalein. Combined treatment with an ERK inhibitor (U0126) and baicalein resulted in a synergistic reduction in MMP-2, MMP-9 and u-PA expression and an increase in TIMP-1 and TIMP-2 expression; the invasive capabilities of MHCC97H cells were also inhibited. In conclusion, baicalein inhibits tumor cell invasion and metastasis by reducing cell motility and migration via the suppression of the ERK pathway, suggesting that baicalein is a potential therapeutic agent for HCC.
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Kim SH, Yu HS, Park HG, Ha K, Kim YS, Shin SY, Ahn YM. Intracerebroventricular administration of ouabain, a Na/K-ATPase inhibitor, activates mTOR signal pathways and protein translation in the rat frontal cortex. Prog Neuropsychopharmacol Biol Psychiatry 2013; 45:73-82. [PMID: 23643758 DOI: 10.1016/j.pnpbp.2013.04.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Revised: 04/02/2013] [Accepted: 04/21/2013] [Indexed: 11/16/2022]
Abstract
Intracerebroventricular (ICV) injection of ouabain, a specific Na/K-ATPase inhibitor, induces behavioral changes in rats in a putative animal model of mania. The binding of ouabain to Na/K-ATPase affects signaling molecules in vitro, including ERK1/2 and Akt, which promote protein translation. We have also reported that ERK1/2 and Akt in the brain are involved in the ouabain-induced hyperactivity of rats. In this study, rats were given an ICV injection of ouabain, and then their frontal cortices were examined to determine the effects of ouabain on the mTOR/p70S6K/S6 signaling pathway and protein translation, which are important in modifications of neural circuits and behavior. Rats showed ouabain-induced hyperactivity up to 8h following injection, and increased phosphorylation levels of mTOR, p70S6K, S6, eIF4B, and 4E-BP at 1, 2, 4, and 8h following ouabain injection. Immunohistochemical analyses revealed that increased p-S6 immunoreactivity in the cytoplasm of neurons by ouabain was evident in the prefrontal, cingulate, and orbital cortex. These findings suggested increased translation initiation in response to ouabain. The rate of protein synthesis was measured as the amount of [(3)H]-leucine incorporation in the cell-free extracts of frontal cortical tissues, and showed a significant increase at 8h after ouabain injection. These results suggest that ICV injection of ouabain induced activation of the protein translation initiation pathway regulated by ERK1/2 and Akt, and prolonged hyperactivity in rats. In conclusion, protein translation pathway could play an important role in ouabain-induced hyperactivity in a rodent model of mania.
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Affiliation(s)
- Se Hyun Kim
- Department of Psychiatry and Behavioral Science & Institute of Human Behavioral Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
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MEK drives cyclin D1 hyperelevation during geroconversion. Cell Death Differ 2013; 20:1241-9. [PMID: 23852369 DOI: 10.1038/cdd.2013.86] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Revised: 06/06/2013] [Accepted: 06/07/2013] [Indexed: 12/26/2022] Open
Abstract
When the cell cycle becomes arrested, MTOR (mechanistic Target of Rapamycin) converts reversible arrest into senescence (geroconversion). Hyperexpression of cyclin D1 is a universal marker of senescence along with hypertrophy, beta-Gal staining and loss of replicative/regenerative potential (RP), namely, the ability to restart proliferation when the cell cycle is released. Inhibition of MTOR decelerates geroconversion, although only partially decreases cyclin D1. Here we show that in p21- and p16-induced senescence, inhibitors of mitogen-activated/extracellular signal-regulated kinase (MEK) (U0126, PD184352 and siRNA) completely prevented cyclin D1 accumulation, making it undetectable. We also used MEL10 cells in which MEK inhibitors do not inhibit MTOR. In such cells, U0126 by itself induced senescence that was remarkably cyclin D1 negative. In contrast, inhibition of cyclin-dependent kinase (CDK) 4/6 by PD0332991 caused cyclin D1-positive senescence in MEL10 cells. Both types of senescence were suppressed by rapamycin, converting it into reversible arrest. We confirmed that the inhibitor of CDK4/6 caused cyclin D1 positive senescence in normal RPE cells, whereas U0126 prevented cyclin D1 expression. Elimination of cyclin D1 by siRNA did not prevent other markers of senescence that are consistent with the lack of its effect on MTOR. Our data confirmed that a mere inhibition of the cell cycle was sufficient to cause senescence, providing MTOR was active, and inhibition of MEK partially inhibited MTOR in a cell-type-dependent manner. Second, hallmarks of senescence may be dissociated, and hyperelevated cyclin D1, a marker of hyperactivation of senescent cells, did not necessarily determine other markers of senescence. Third, inhibition of MEK was sufficient to eliminate cyclin D1, regardless of MTOR.
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Whyte C, Thies F, Peyrol L, Balcerzak D. N-3 long-chain polyunsaturated fatty acids inhibit smooth muscle cell migration by modulating urokinase plasminogen activator receptor through MEK/ERK-dependent and -independent mechanisms. J Nutr Biochem 2012; 23:1378-83. [DOI: 10.1016/j.jnutbio.2011.08.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2011] [Revised: 08/23/2011] [Accepted: 08/30/2011] [Indexed: 11/16/2022]
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The MAPK MEK1/2-ERK1/2 Pathway and Its Implication in Hepatocyte Cell Cycle Control. Int J Hepatol 2012; 2012:328372. [PMID: 23133759 PMCID: PMC3485978 DOI: 10.1155/2012/328372] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2012] [Revised: 09/06/2012] [Accepted: 09/10/2012] [Indexed: 12/15/2022] Open
Abstract
Primary cultures of hepatocytes are powerful models in studying the sequence of events that are necessary for cell progression from a G0-like state to S phase. The models mimic the physiological process of hepatic regeneration after liver injury or partial hepatectomy. Many reports suggest that the mitogen-activated protein kinase (MAPK) ERK1/2 can support hepatocyte proliferation in vitro and in vivo and the MEK/ERK cascade acts as an essential element in hepatocyte responses induced by the EGF. Moreover, its disregulation has been associated with the promotion of tumor cell growth of a variety of tumors, including hepatocellular carcinoma. Whereas the strict specificity of action of ERK1 and ERK2 is still debated, the MAPKs may have specific biological functions under certain contexts and according to the differentiation status of the cells, notably hepatocytes. In this paper, we will focus on MEK1/2-ERK1/2 activations and roles in normal rodent hepatocytes in vitro and in vivo after partial hepatectomy and in human hepatocarcinoma cells. The possible specificity of ERK1 and ERK2 in normal and transformed hepatocyte will be discussed in regard to other differentiated and undifferentiated cellular models.
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Nowicki TS, Zhao H, Darzynkiewicz Z, Moscatello A, Shin E, Schantz S, Tiwari RK, Geliebter J. Downregulation of uPAR inhibits migration, invasion, proliferation, FAK/PI3K/Akt signaling and induces senescence in papillary thyroid carcinoma cells. Cell Cycle 2011; 10:100-7. [PMID: 21191179 DOI: 10.4161/cc.10.1.14362] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Papillary thyroid carcinoma (PTC) is the most common endocrine and thyroid malignancy. The urokinase plasminogen activator receptor (uPAR) plays an important role in cancer pathogenesis, including breakdown of the extracellular matrix, invasion, and metastasis. Additionally, there is increasing evidence that uPAR also promotes tumorigenesis via the modulation of multiple signaling pathways. BRAFV600E, the most common initial genetic mutation in PTC, leads to ERK1/2 hyperphosphorylation, which has been shown in numerous cancers to induce uPAR. Treatment of the BRAFV600E-positive PTC cell line, BCPAP, with the MEK/ERK inhibitor U0126 reduced uPAR RNA levels by 90%. siRNA-mediated down-regulation of uPAR in BCPAP cells resulted in greatly decreased activity in the focal adhesion kinase (FAK)/phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway. This phenomenon was concurrent with drastically reduced proliferation rates and decreased clonigenic survival, as well as demonstrated senescence-associated nuclear morphology and induction of b-galactosidase activity. uPAR-knockdown BCPAP cells also displayed greatly reduced migration and invasion rates, as well as a complete loss of the cells' ability to augment their invasiveness following plasminogen supplementation. Taken together, these data provide new evidence of a novel role for uPAR induction (as a consequence of constitutive ERK1/2 activation) as a central component in PTC pathogenesis, and highlight the potential of uPAR as a therapeutic target.
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Affiliation(s)
- Theodore S Nowicki
- Department of Microbiology and Immunology, New York Medical College, Valhalla, NY, USA
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18
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Effects of neonatal MK-801 treatment on p70S6K-S6/eIF4B signal pathways and protein translation in the frontal cortex of the developing rat brain. Int J Neuropsychopharmacol 2010; 13:1233-46. [PMID: 20064280 DOI: 10.1017/s1461145709991192] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Systemic injections of MK-801, a selective NMDAR antagonist, into neonatal rats induces long-term neurochemical and behavioural changes. It has been suggested that these changes form the neurodevelopmental basis for schizophrenia-like behaviour in rats. In this study, 7-d-old rats were treated with MK-801, and their frontal cortices were examined to investigate the effects on p70S6K-S6 signal pathway and on protein translation, which play crucial roles in the neurodevelopmental process. MK-801, in doses of 0.5 and 1.0 mg/kg, induced a decrease in phosphorylation of p70S6K and its substrates, S6 and eIF4B, in the first 8 h, and no change at 24 and 48 h. These effects were more prominent after two injections of MK-801 than one. Decreased S6 phosphorylation by MK-801 was evident in the prefrontal, cingulate, and insular cortex. In two representative upstream p70S6K-S6 pathways related to ERK1/2 and Akt, changes in ERK1/2-p90RSK phosphorylation were accompanied by changes of p70S6K-S6. Although two MK-801 injections induced a dose-dependent decrease in phosphorylation of Akt and mTOR at 4 and 8 h, a single injection did not produce a significant effect. Protein synthesis rate, measured by [3H]leucine incorporation in frontal cortical tissue, was reduced until 24 h after two MK-801 (1.0 mg/kg) injections. In summary, this study found that neonatal MK-801 treatment induced dysregulation in the p70S6K-S6/eIF4B pathway and protein translation in the frontal cortex of the developing rat brain, which may suggest an important role of protein translation machinery in the MK-801 neurodevelopmental animal model of schizophrenia.
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Leung THY, Yam JWP, Chan LK, Ching YP, Ng IOL. Deleted in liver cancer 2 suppresses cell growth via the regulation of the Raf-1-ERK1/2-p70S6K signalling pathway. Liver Int 2010; 30:1315-23. [PMID: 20629949 DOI: 10.1111/j.1478-3231.2010.02307.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
BACKGROUND Deleted in liver cancer 2 (DLC2) gene, a putative tumour suppressor gene, encodes a Rho GTPase-activating protein (RhoGAP) with GAP activity specific for RhoA. It exhibits tumour suppressor functions and inhibits tumour cell proliferation, migration as well as transformation. AIMS In this study, we aimed to investigate the underlying mechanisms of the DLC2 gene in suppressing cell migration and cell growth. HepG2 hepatoma cells were stably transfected with the DLC2γ isoform, which contains the RhoGAP domain. METHODS AND RESULTS On performing immunofluorescence staining and Western blot analysis, the expression of the focal adhesion protein paxillin was found to be much reduced in DLC2γ-stable clones. Upon flow cytometric analysis of the cell cycle profiles, the DLC2γ-stable clones were shown to have a higher population of cells arrested at the G1 phase than the EGFP vector-stable clone, suggesting that downregulation of RhoA activity in DLC2γ-stable clones inhibited cell cycle progression. In the DLC2γ-stable clone, the levels of Raf-1 and extracellular signal-regulated kinase (ERK) 1/2 were decreased as compared with those of the parental HepG2, EGFP vector and DLC2γ-GAP defective mutant-stable clones. Furthermore, the ribosomal kinase p70S6K, a downstream target of ERK1/2, was suppressed in the DLC2-stable clones. On the contrary, when DLC2 was knocked down by siRNA in HepG2 cells, the expression levels of phospho-p70S6K and phospho-ERK1/2 were upregulated. CONCLUSION Our data show that DLC2 inhibits the activity of Raf-1-ERK1/2-p70S6K via its RhoGAP function, resulting in the suppression of cell growth. Further studies on the molecular signalling between DLC2 and p70S6K may provide an insight into its growth suppressor function.
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Huo Q, Zheng ST, Tuersun A, Huang CG, Liu Q, Zhang X, Sheyhidin I, Lu XM. shRNA interference for extracellular signal-regulated kinase 2 can inhibit the growth of esophageal cancer cell line Eca109. J Recept Signal Transduct Res 2010; 30:170-7. [PMID: 20415541 DOI: 10.3109/10799891003786200] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
BACKGROUND Esophageal squamous cell carcinoma is one of the most common digestive tract cancers with 5-year survival rate less than 10% owing to its poor prognosis. Mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) signaling pathway has been mainly involved in the pathogenesis of various cancers. In present study, we investigated the role of ERK2 in human esophageal cancer cell line Eca109. METHODS Short-hairpin RNA (shRNA) interference vector targeted ERK2 was constructed using pGeneclip U1 hairpin cloning systems, then transfected into Eca109 cell line. The transfection efficiency was observed by fluorescence microscope and cell growth after transfection with shRNA-ERK2 vector was determined by methylthiazolyl blue tetrazolium (MTT) assay. The ERK2 expression after transfection was detected by western-blotting. The cell apoptosis and cell-cycle was analyzed by flow cytometry. The role of p-ERK2 was confirmed by immunohistochemistry and soft agar colony formation assay. RESULTS The growth of Eca109 transfected with shRNA-ERK2 vector was obviously inhibited compared to control group via MTT analysis. The inhibition rate after transfection with shRNA-ERK2 for 96 h was 10.45%, the expression of ERK2 was obviously reduced compared to the control analyzed by western-blot, cell apoptosis was 9.7% (compared to control, P < 0.05), and cell-cycle was arrested at G1 phase. CONCLUSIONS In present study we demonstrated for the first time that transfection with shRNA-ERK2 targeted ERK2 into Eca109 cells can inhibit growth of Eca109, inducing cell apoptosis and influencing cell-cycle. Together, these results we obtained suggested that ERK2 plays an important role in cell growth of Eca109.
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Affiliation(s)
- Qi Huo
- Medical Research Center, First Affiliated Hospital, Xinjiang Medical University, Urumqi, Xinjiang Uygur Autonomous Region, China
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Gailhouste L, Ezan F, Bessard A, Frémin C, Rageul J, Langouët S, Baffet G. RNAi-mediated MEK1 knock-down prevents ERK1/2 activation and abolishes human hepatocarcinoma growth in vitro and in vivo. Int J Cancer 2010; 126:1367-77. [PMID: 19816936 DOI: 10.1002/ijc.24950] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The mitogen-activated protein kinases MEK/ERK pathway regulates fundamental processes in malignant cells and represents an attractive target in the development of new cancer treatments especially for human hepatocarcinoma highly resistant to chemotherapy. Although gene extinction experiments have suggested distinct roles for these proteins, the MEK/ERK cascade remains widely considered as exhibiting an overlap of functions. To investigate the functionality of each kinase in tumorigenesis, we have generated stably knock-down clones for MEK1/2 and ERK1/2 isoforms in the human hepatocellular carcinoma line HuH7. Our results have shown that RNAi strategy allows a specific disruption of the targeted kinases and argued for the critical function of MEK1 in liver tumor growth. Transient and stable extinction experiments demonstrated that MEK1 isoform acts as a major element in the signal transduction by phosphorylating ERK1 and ERK2 after growth factors stimulation, whereas oncogenic level of ERK1/2 phosphorylation appears to be MEK1 and MEK2 dependent in basal condition. In addition, silencing of MEK1 or ERK2 abolished cell proliferation and DNA replication in vitro as well as tumor growth in vivo after injection in rodent. In contrast, targeting MEK2 or ERK1 had no effect on hepatocarcinoma progression. These results strongly corroborate the relevance of targeting the MEK cascade as attested by pharmacologic drugs and support the potential application of RNAi in future development of more effective cancer therapies. Our study emphasizes the importance of the MEK/ERK pathway in human hepatocarcinoma cell growth and argues for a crucial role of MEK1 and ERK2 in this regulation.
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Affiliation(s)
- Luc Gailhouste
- EA 4427-SeRAIC, IFR 140, Université de Rennes 1, F-35043 Rennes, France
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22
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Yang J, Duh EJ, Caldwell RB, Behzadian MA. Antipermeability function of PEDF involves blockade of the MAP kinase/GSK/beta-catenin signaling pathway and uPAR expression. Invest Ophthalmol Vis Sci 2010; 51:3273-80. [PMID: 20089873 DOI: 10.1167/iovs.08-2878] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Pigment epithelium-derived factor (PEDF) is a potent inhibitor of vascular endothelial growth factor (VEGF)-induced endothelial permeability. The goal of this study was to understand the mechanism by which PEDF blocks VEGF-induced increases in vascular permeability. METHODS The paracellular permeability of bovine retinal endothelial (BRE) cells was measured by assaying transendothelial cell electrical resistance and tracer flux. Western blot analysis was used to show phosphorylation of VEGFR2, MAP kinases, and glycogen synthase kinase 3 (GSK3)-beta. Confocal imaging and Western blot analysis were used to determine subcellular distribution of beta-catenin. Real-time RT-PCR and Western blot analysis were used to quantify urokinase plasminogen activator receptor (uPAR) expression. RESULTS PEDF blocked VEGF-induced phosphorylation of extracellular signal-regulated kinase (ERK), p38 MAP kinase, the p38 substrate MAP kinase-activated protein kinase-2 (MAPKAPK-2), and GSK3-beta, but it had no effect on the phosphorylation of VEGFR2. In addition, the VEGF-induced transcriptional activation of beta-catenin and uPAR expression were blocked by PEDF and by inhibitors of p38 and MEK. Finally, the VEGF-induced increase in permeability was blocked by both PEDF and the same kinase inhibitors. CONCLUSIONS The data suggest that p38 MAP kinase and ERK act upstream of GSK/beta-catenin in VEGF-induced activation of the uPA/uPAR system and that PEDF-mediated inhibition of the VEGF-induced increase in vascular permeability involves blockade of this pathway. These findings are important for developing precise and potent therapies for treatment of diseases characterized by vascular barrier dysfunction.
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Abstract
Accumulating evidence indicates that p44(ERK1) and p42(ERK2) mitogen-activated protein kinases (MAPKs) have distinct quantitative roles in cell signaling. In our recently proposed model of regulation of ERK1 and ERK2, p42 plays a major role in delivering signals from the cell membrane to the nucleus, while p44 acts as a partial agonist of ERK2 toward effectors and downstream activators, thus providing a fine tuning system of the global signaling output. Here, we describe systems to modulate MAPK signaling in vitro and in vivo via lentiviral vector (LV)-mediated gene transfer, using three systems: RNAi with small hairpin RNAs, microRNA-mediated gene knockdown, and expression of signaling-interfering mutants of MEK1. We show, by using proliferation assays in mouse embryo fibroblasts (MEF) and NIH 3T3 cells, that gene knockdown of ERK1 promotes cell proliferation in a manner indistinguishable from a constitutively active MEK1 construct, while ERK2 RNAi causes a significant growth arrest, similar to that observed with the ectopic expression of a dominant negative MEK1 mutant.
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Xue A, Xue M, Jackson C, Smith RC. Suppression of urokinase plasminogen activator receptor inhibits proliferation and migration of pancreatic adenocarcinoma cells via regulation of ERK/p38 signaling. Int J Biochem Cell Biol 2009; 41:1731-8. [PMID: 19433314 DOI: 10.1016/j.biocel.2009.03.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2008] [Revised: 03/12/2009] [Accepted: 03/12/2009] [Indexed: 01/12/2023]
Abstract
Pancreatic ductal adenocarcinoma (PDAC) expresses high levels of urokinase-type plasminogen activator (uPA), its receptor (uPAR) and plasminogen activator inhibitor (PAI)-2, which may play an important role in PDAC progression. The overexpression of uPAR predicted short survival in PDAC patients. In this study, two different PDAC cell lines were used to examine the effect of small interfering (si) RNAs to uPAR, uPA and PAI-2 on proliferation, apoptosis, migration and MAP kinase activation. In both PDAC cell lines, siRNA to uPAR significantly inhibited cell proliferation and migration and stimulated apoptosis, to a greater extent than uPA siRNA. When either PDAC cell line was treated with uPAR siRNA, the level of phosphorylated ERK (p-ERK) decreased substantially, whereas phosphorylated p38 (p-p38) increased when compared to non-silencing control, uPA siRNA or PAI-2 siRNA treatment. This resulted in enhancement of the p-p38/p-ERK ratio which favors cancer cell arrest. Interestingly, uPAR protein expression was suppressed by p-ERK inhibition and stimulated with p-p38 inhibition, suggesting the presence of a positive feedback loop between uPAR and ERK. In summary, our data indicate that, of the uPA system, uPAR exerts the strongest effects on PDAC cells, by acting through the ERK signaling pathway via a positive feedback loop. Disruption of this loop with uPAR siRNA or inhibitor of p-ERK, inhibits PDAC proliferation and migration and promotes apoptosis. These findings suggest that uPAR strongly contributes to PDAC progression and may be considered as a potential anti-pancreatic cancer target.
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Affiliation(s)
- Aiqun Xue
- Department of Surgery, The University of Sydney, Royal North Shore Hospital, St Leonards, NSW, Australia
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Frémin C, Bessard A, Ezan F, Gailhouste L, Régeard M, Le Seyec J, Gilot D, Pagès G, Pouysségur J, Langouët S, Baffet G. Multiple division cycles and long-term survival of hepatocytes are distinctly regulated by extracellular signal-regulated kinases ERK1 and ERK2. Hepatology 2009; 49:930-9. [PMID: 19177593 DOI: 10.1002/hep.22730] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
UNLABELLED We investigated the specific role of the mitogen-activated protein kinase (MAPK) extracellular signal-regulated kinase 1 (ERK1)/ERK2 pathway in the regulation of multiple cell cycles and long-term survival of normal hepatocytes. An early and sustained epidermal growth factor (EGF)-dependent MAPK activation greatly improved the potential of cell proliferation. In this condition, almost 100% of the hepatocytes proliferated, and targeting ERK1 or ERK2 via RNA interference revealed the specific involvement of ERK2 in this regulation. However, once their first cell cycle was performed, hepatocytes failed to undergo a second round of replication and stayed blocked in G1 phase. We demonstrated that sustained EGF-dependent activation of the MAPK/ERK kinase (MEK)/ERK pathway was involved in this blockage as specific transient inhibition of the cascade repotentiated hepatocytes to perform a new wave of replication and multiple cell cycles. We identified this mechanism by showing that this blockage was in part supported by ERK2-dependent p21 expression. Moreover, continuous MEK inhibition was associated with a lower apoptotic engagement, leading to an improvement of survival up to 3 weeks. Using RNA interference and ERK1 knockout mice, we extended these results by showing that this improved survival was due to the specific inhibition of ERK1 expression/phosphorylation and did not involve ERK2. CONCLUSION Our results emphasize that transient MAPK inhibition allows multiple cell cycles in primary cultures of hepatocytes and that ERK2 has a key role in the regulation of S phase entry. Moreover, we revealed a major and distinct role of ERK1 in the regulation of hepatocyte survival. Taken together, our results represent an important advance in understanding long-term survival and cell cycle regulation of hepatocytes.
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Affiliation(s)
- Christophe Frémin
- INSERM U522, UPRES SeRAIC, IFR 140 Université de Rennes, Rennes, France
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Wu WKK, Sung JJY, Yu L, Li ZJ, Chu KM, Cho CH. Constitutive hypophosphorylation of extracellular signal-regulated kinases-1/2 and down-regulation of c-Jun in human gastric adenocarcinoma. Biochem Biophys Res Commun 2008; 373:330-4. [PMID: 18570890 DOI: 10.1016/j.bbrc.2008.06.025] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2008] [Accepted: 06/10/2008] [Indexed: 12/16/2022]
Abstract
Hyperphosphorylation of extracellular signal-regulated protein kinases-1/2 (ERK1/2) is known to promote cancer cell proliferation. We therefore investigated the constitutive phosphorylation levels of ERK1/2 and the expression of its downstream targets c-Fos, c-Jun, and cyclooxygenase-2 (COX-2) in biopsied human gastric cancer tissues. Results showed that ERK1/2 phosphorylation and c-Jun expression were significantly lowered in gastric cancer compared with the non-cancer adjacent tissues. The expression of c-Fos, however, was not altered while COX-2 was significantly up-regulated. To conclude, we demonstrate that hypophosphorylation of ERK1/2 may occur in gastric cancer. Such discovery may have implication in the application of pathway-directed therapy for this malignant disease.
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Affiliation(s)
- William Ka Kei Wu
- Department of Pharmacology, Basic Medical Sciences Building, The Chinese University of Hong Kong, Shatin, NT, Hong Kong, China
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Bessard A, Frémin C, Ezan F, Fautrel A, Gailhouste L, Baffet G. RNAi-mediated ERK2 knockdown inhibits growth of tumor cells in vitro and in vivo. Oncogene 2008; 27:5315-25. [PMID: 18521085 DOI: 10.1038/onc.2008.163] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The MAPK MEK/ERK pathway is often upregulated in cancer cells and represents an attractive target for development of anticancer drugs. Only few data concerning the specific functions of ERK1 and 2 are reported in the literature. In this report, we investigated the specific role of ERK1 and 2 in liver tumor growth both in vitro and in vivo. DNA synthesis and cells in S phase analysed by flow cytometry, correlated with strong inhibition of Cdk1 and cyclin E levels, are strongly reduced after exposure to the MEK inhibitor, U0126. We obtained a significant reduction of colony formation in soft agar assays and a reduction in the size of tumor xenografts in nude mice treated with U0126. Then, we could specifically abolished ERK1 or 2 expression by small-interfering RNA (siRNA) and demonstrated that ERK2 knockdown but not ERK1 interferes with the process of replication. Moreover, we found that colony formation and tumor growth in vivo were significantly inhibited by targeting ERK2 using stable chemically modified siRNA. Taken together, our results emphasize the importance of the MEK/ERK pathway in liver cancer cell growth in vitro and in vivo and argue for a crucial role of ERK2 in this regulation.
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Affiliation(s)
- A Bessard
- INSERM U522, IFR 140, Hopital Pontchaillou, Université de Rennes1, Rennes, France
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Du J, Guan T, Zhang H, Xia Y, Liu F, Zhang Y. Inhibitory crosstalk between ERK and AMPK in the growth and proliferation of cardiac fibroblasts. Biochem Biophys Res Commun 2008; 368:402-7. [PMID: 18243130 DOI: 10.1016/j.bbrc.2008.01.099] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2007] [Accepted: 01/19/2008] [Indexed: 12/31/2022]
Abstract
Extracellular signal-regulated kinase (ERK) is one of the key protein kinases that regulate the growth and proliferation in cardiac fibroblasts (CFs). As an energy sensor of cellular metabolism, AMP-activated protein kinase (AMPK) is found recently to be involved in myocardial remodeling. In this study, we investigated the crosstalk between ERK and AMPK in the growth and proliferation of CFs. In neonatal rat cardiac fibroblasts (NRCFs), we found that serum significantly inhibited basal AMPK phosphorylation between 10min and 24h and also partially inhibited AMPK phosphorylation by AMPK activator, 5-aminoimidazole-4-carboxamide-ribonucleoside (AICAR). Furthermore, ERK inhibitor could greatly reverse the inhibition of AMPK by serum. Conversely, activation of AMPK by AICAR also showed a significant inhibition of basal and serum-induced ERK phosphorylation but it showed a delayed and steadfast inhibition which appeared after 60min and lasted until 12h. Moreover, inhibition of ERK could repress the activation of p70S6K, an important kinase in cardiac proliferation, and AICAR could also inhibit p70S6K phosphorylation. In addition, under both serum and serum-free medium, AICAR significantly inhibited the DNA synthesis and cell numbers, and reduced cells at S phase. In conclusion, AMPK activation with AICAR inhibited growth and proliferation in cardiac fibroblasts, which involved inhibitory interactions between ERK and AMPK. This is the first report that AMPK could be a target of ERK in growth factors-induced proliferation, which may give a new mechanism that growth factors utilize in their promotion of proliferation in cardiac fibroblasts.
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Affiliation(s)
- Jianhai Du
- Institute of Vascular Medicine, Peking University Third Hospital and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing 100083, PR China
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Eckstein N, Servan K, Girard L, Cai D, von Jonquieres G, Jaehde U, Kassack MU, Gazdar AF, Minna JD, Royer HD. Epidermal growth factor receptor pathway analysis identifies amphiregulin as a key factor for cisplatin resistance of human breast cancer cells. J Biol Chem 2008; 283:739-50. [PMID: 17942395 PMCID: PMC2760391 DOI: 10.1074/jbc.m706287200] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The use of platinum complexes for the therapy of breast cancer is an emerging new treatment modality. To gain insight into the mechanisms underlying cisplatin resistance in breast cancer, we used estrogen receptor-positive MCF-7 cells as a model system. We generated cisplatin-resistant MCF-7 cells and determined the functional status of epidermal growth factor receptor (EGFR), MAPK, and AKT signaling pathways by phosphoreceptor tyrosine kinase and phospho-MAPK arrays. The cisplatin-resistant MCF-7 cells are characterized by increased EGFR phosphorylation, high levels of AKT1 kinase activity, and ERK1 phosphorylation. In contrast, the JNK and p38 MAPK modules of the MAPK signaling pathway were inactive. These conditions were associated with inactivation of the p53 pathway and increased BCL-2 expression. We investigated the expression of genes encoding the ligands for the ERBB signaling cascade and found a selective up-regulation of amphiregulin expression, which occurred at later stages of cisplatin resistance development. Amphiregulin is a specific ligand of the EGFR (ERBB1) and a potent mitogen for epithelial cells. After exposure to cisplatin, the resistant MCF-7 cells secreted amphiregulin protein over extended periods of time, and knockdown of amphiregulin expression by specific short interfering RNA resulted in a nearly complete reversion of the resistant phenotype. To demonstrate the generality and importance of our findings, we examined amphiregulin expression and cisplatin resistance in a variety of human breast cancer cell lines and found a highly significant correlation. In contrast, amphiregulin levels did not significantly correlate with cisplatin resistance in a panel of lung cancer cell lines. We have thus identified a novel function of amphiregulin for cisplatin resistance in human breast cancer cells.
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Affiliation(s)
- Niels Eckstein
- Stiftung Center of Advanced European Studies and Research, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany
| | - Kati Servan
- Stiftung Center of Advanced European Studies and Research, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany
| | - Luc Girard
- Hamon Center for Therapeutic Oncology Research, University of Texas Southwestern Medical Center, Dallas, Texas 75390-8593
| | - Di Cai
- Hamon Center for Therapeutic Oncology Research, University of Texas Southwestern Medical Center, Dallas, Texas 75390-8593
| | - Georg von Jonquieres
- Stiftung Center of Advanced European Studies and Research, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany
| | - Ulrich Jaehde
- Department of Clinical Pharmacy, University of Bonn, An der Immenburg 4, 53121 Bonn, Germany
| | - Matthias U. Kassack
- Pharmaceutical Biochemistry, Institute of Pharmaceutical and Medicinal Chemistry, University of Duesseldorf, Universitaetsstrasse 1, 40225 Duesseldorf, Germany
| | - Adi F. Gazdar
- Hamon Center for Therapeutic Oncology Research, University of Texas Southwestern Medical Center, Dallas, Texas 75390-8593
| | - John D. Minna
- Hamon Center for Therapeutic Oncology Research, University of Texas Southwestern Medical Center, Dallas, Texas 75390-8593
| | - Hans-Dieter Royer
- Stiftung Center of Advanced European Studies and Research, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany
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