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Marjanovic J, Ramirez HA, Jozic I, Stone RC, Wikramanayake TC, Head CR, Abdo Abujamra B, Ojeh N, Kirsner RS, Lev-Tov H, Pastar I, Tomic-Canic M. Dichotomous role of miR193b-3p in diabetic foot ulcers maintains inhibition of healing and suppression of tumor formation. Sci Transl Med 2022; 14:eabg8397. [PMID: 35544594 PMCID: PMC9707408 DOI: 10.1126/scitranslmed.abg8397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Despite the hyperproliferative environment marked by activation of β-catenin and overexpression of c-myc, the epidermis surrounding chronic diabetic foot ulcers (DFUs) is clinically hypertrophic and nonmigratory yet does not undergo malignant transformation. We identified miR193b-3p as a master regulator that contributes to this unique cellular phenotype. We determined that induction of tumor suppressor miR193b-3p is a unique feature of DFUs that is not found in venous leg ulcers, acute wounds, or cutaneous squamous cell carcinoma (SCC). Genomic analyses of DFUs identified suppression of the miR193b-3p target gene network that orchestrates cell motility. Inhibition of migration and wound closure was further confirmed by overexpression of miR193b-3p in human organotypic and murine in vivo wound models, whereas miR193b-3p knockdown accelerated wound reepithelialization in human ex vivo and diabetic murine wounds in vivo. The dominant negative effect of miR193b-3p on keratinocyte migration was maintained in the presence of promigratory miR31-5p and miR15b-5p, which were also overexpressed in DFUs. miR193b-3p mediated antimigratory activity by disrupting stress fiber formation and by decreasing activity of GTPase RhoA. Conversely, miR193b-3p targets that typically participate in malignant transformation were found to be differentially regulated between DFUs and SCC, including the proto-oncogenes KRAS (Kirsten rat sarcoma viral proto-oncogene) and KIT (KIT proto-oncogene). Although miR193b-3p acts as a tumor suppressor contributing to low tumor incidence in DFUs, it also acts as a master inhibitor of cellular migration and epithelialization in DFUs. Thus, miR193b-3p may represent a target for wound healing induction, cancer therapeutics, and diagnostics.
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Affiliation(s)
- Jelena Marjanovic
- Wound Healing and Regenerative Medicine Research Program, Dr. Phillip Frost Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, FL, 33136, USA
| | - Horacio A Ramirez
- Wound Healing and Regenerative Medicine Research Program, Dr. Phillip Frost Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, FL, 33136, USA
| | - Ivan Jozic
- Wound Healing and Regenerative Medicine Research Program, Dr. Phillip Frost Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, FL, 33136, USA
| | - Rivka C Stone
- Wound Healing and Regenerative Medicine Research Program, Dr. Phillip Frost Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, FL, 33136, USA
| | - Tongyu C Wikramanayake
- Wound Healing and Regenerative Medicine Research Program, Dr. Phillip Frost Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, FL, 33136, USA
| | - Cheyanne R Head
- Wound Healing and Regenerative Medicine Research Program, Dr. Phillip Frost Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, FL, 33136, USA
| | - Beatriz Abdo Abujamra
- Wound Healing and Regenerative Medicine Research Program, Dr. Phillip Frost Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, FL, 33136, USA
| | - Nkemcho Ojeh
- Wound Healing and Regenerative Medicine Research Program, Dr. Phillip Frost Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, FL, 33136, USA.,Faculty of Medical Sciences, The University of the West Indies, Bridgetown BB11000, Barbados
| | - Robert S Kirsner
- Wound Healing and Regenerative Medicine Research Program, Dr. Phillip Frost Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, FL, 33136, USA
| | - Hadar Lev-Tov
- Wound Healing and Regenerative Medicine Research Program, Dr. Phillip Frost Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, FL, 33136, USA
| | - Irena Pastar
- Wound Healing and Regenerative Medicine Research Program, Dr. Phillip Frost Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, FL, 33136, USA
| | - Marjana Tomic-Canic
- Wound Healing and Regenerative Medicine Research Program, Dr. Phillip Frost Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, FL, 33136, USA
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2
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Di Segni M, Virdia I, Verdina A, Amoreo CA, Baldari S, Toietta G, Diodoro MG, Mottolese M, Sperduti I, Moretti F, Buglioni S, Soddu S, Di Rocco G. HIPK2 cooperates with KRAS signaling and associates with colorectal cancer progression. Mol Cancer Res 2022; 20:686-698. [PMID: 35082165 DOI: 10.1158/1541-7786.mcr-21-0628] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 11/25/2021] [Accepted: 01/21/2022] [Indexed: 11/16/2022]
Abstract
HIPK2 is an evolutionary conserved kinase that has gained attention as a fine tuner of multiple signaling pathways, among which those commonly altered in colorectal cancer (CRC). The aim of this study was to evaluate the relationship of HIPK2 expression with progression markers and mutational pattern and gain insights into the contribution of HIPK2 activity in CRC. We evaluated a retrospective cohort of CRC samples by immunohistochemistry for HIPK2 expression and by NGS for the detection of mutations of cancer associated genes. We show that the percentage of HIPK2 positive cells increases with tumor progression, significantly correlates with TNM staging and associates with a worse outcome. In addition, we observed that high HIPK2 expression significantly associates with KRAS mutations but not with other cancer related genes. Functional characterization of the link between HIPK2 and KRAS show that activation of the RAS pathway either due to KRAS mutation or via upstream receptor stimulation, increases HIPK2 expression at the protein level. Of note, HIPK2 physically participates in the active RAS complex while HIPK2 depletion impairs ERK phosphorylation and the growth of tumors derived from KRAS mutated CRC cells. Overall, this study identifies HIPK2 as a prognostic biomarker candidate in CRC patients and underscores a previously unknown functional link between HIPK2 and the KRAS signaling pathway. Implications: Our data indicate HIPK2 as a new player in the complex picture of the KRAS signaling network, providing rationales for future clinical studies and new treatment strategies for KRAS mutated CRC.
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Affiliation(s)
- Micol Di Segni
- Department of Research, Advanced Diagnostic and Technological Innovation, IRCCS - Regina Elena National Cancer Institute
| | - Ilaria Virdia
- Department of Research, Advanced Diagnostic and Technological Innovation, Regina Elena National Cancer Institute, IRCCS - Regina Elena National Cancer Institute
| | - Alessandra Verdina
- Department of Research, Advanced Diagnostic and Technological Innovation, IRCCS - Regina Elena National Cancer Institute
| | - Carla Azzurra Amoreo
- Research, Advanced Diagnostic, and Technological Innovation, Istituto Nazionale Tumori Regina Elena
| | - Silvia Baldari
- Department of Research, Advanced Diagnostic and Technological Innovation, Regina Elena National Cancer Institute
| | - Gabriele Toietta
- Department of Research, Advanced Diagnostic and Technological Innovation, Regina Elena National Cancer Institute
| | | | | | | | - Fabiola Moretti
- Institute of Biochemistry and Cell Biology, National Research Council of Italy
| | | | - Silvia Soddu
- Department of Research, Advanced Diagnostic and Technological Innovation, IRCCS Regina Elena National Cancer Institute
| | - Giuliana Di Rocco
- Department of Research and Advanced Technologies, IRCCS - Regina Elena National Cancer Institute
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3
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Guo R, Zhao M, Liu H, Su R, Mao Q, Gong L, Cao X, Hao Y. Uncovering the pharmacological mechanisms of Xijiao Dihuang decoction combined with Yinqiao powder in treating influenza viral pneumonia by an integrative pharmacology strategy. Biomed Pharmacother 2021; 141:111676. [PMID: 34126353 DOI: 10.1016/j.biopha.2021.111676] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Revised: 04/22/2021] [Accepted: 04/24/2021] [Indexed: 12/12/2022] Open
Abstract
Xijiao Dihuang decoction combined with Yinqiao powder (XDD-YQP) is a classical combination formula; however, its therapeutic effects in treating influenza viral pneumonia and the pharmacological mechanisms remain unclear. The therapeutic effect of XDD-YQP in influenza viral pneumonia was evaluated in mice. Subsequently, an everted gut sac model coupled with UPLC/Q-TOF MS were used to screen and identify the active compounds of XDD-YQP. Furthermore, network pharmacological analysis was adopted to probe the mechanisms of the active compounds. Lastly, we verified the targets predicted from network pharmacological analysis by differential bioinformatics analysis. Animal experiments showed that XDD-YQP has a therapeutic effect on influenza viral pneumonia. Moreover, 113 active compounds were identified from intestinal absorbed solutions of XDD-YQP. Using network pharmacological analysis, 90 major targets were selected as critical in the treatment of influenza viral pneumonia through 12 relevant pathways. Importantly, the MAPK signaling pathway was found to be closely associated with the other 11 pathways. Moreover, seven key targets, EGFR, FOS, MAPK1, MAP2K1, HRAS, NRAS, and RELA, which are common targets in the MAPK signaling pathway, were investigated. These seven key targets were identified as differentially expressed genes (DEGs) between influenza virus-infected and uninfected individuals. Hence, the seven key targets in the MAPK signaling pathway may play a vital role in the treatment of influenza viral pneumonia with XDD-YQP. This research may offer an integrative pharmacology strategy to clarify the pharmacological mechanisms of traditional Chinese medicines. The results provide a theoretical basis for a broader clinical application of XDD-YQP.
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Affiliation(s)
- Rui Guo
- School of Life Sciences, Beijing University of Chinese Medicine, Beijing, China
| | - Mengfan Zhao
- School of Life Sciences, Beijing University of Chinese Medicine, Beijing, China
| | - Hui Liu
- School of Life Sciences, Beijing University of Chinese Medicine, Beijing, China
| | - Rina Su
- School of Life Sciences, Beijing University of Chinese Medicine, Beijing, China
| | - Qin Mao
- School of Life Sciences, Beijing University of Chinese Medicine, Beijing, China
| | - Leilei Gong
- Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing, China
| | - Xu Cao
- School of Life Sciences, Beijing University of Chinese Medicine, Beijing, China
| | - Yu Hao
- School of Life Sciences, Beijing University of Chinese Medicine, Beijing, China.
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4
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Tripathi R, Liu Z, Jain A, Lyon A, Meeks C, Richards D, Liu J, He D, Wang C, Nespi M, Rymar A, Wang P, Wilson M, Plattner R. Combating acquired resistance to MAPK inhibitors in melanoma by targeting Abl1/2-mediated reactivation of MEK/ERK/MYC signaling. Nat Commun 2020; 11:5463. [PMID: 33122628 PMCID: PMC7596241 DOI: 10.1038/s41467-020-19075-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 09/29/2020] [Indexed: 12/20/2022] Open
Abstract
Metastatic melanoma remains an incurable disease for many patients due to the limited success of targeted and immunotherapies. BRAF and MEK inhibitors reduce metastatic burden for patients with melanomas harboring BRAF mutations; however, most eventually relapse due to acquired resistance. Here, we demonstrate that ABL1/2 kinase activities and/or expression are potentiated in cell lines and patient samples following resistance, and ABL1/2 drive BRAF and BRAF/MEK inhibitor resistance by inducing reactivation of MEK/ERK/MYC signaling. Silencing/inhibiting ABL1/2 blocks pathway reactivation, and resensitizes resistant cells to BRAF/MEK inhibitors, whereas expression of constitutively active ABL1/2 is sufficient to promote resistance. Significantly, nilotinib (2nd generation ABL1/2 inhibitor) reverses resistance, in vivo, causing prolonged regression of resistant tumors, and also, prevents BRAFi/MEKi resistance from developing in the first place. These data indicate that repurposing the FDA-approved leukemia drug, nilotinib, may be effective for prolonging survival for patients harboring BRAF-mutant melanomas.
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Affiliation(s)
- Rakshamani Tripathi
- Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, Lexington, KY, 40536, USA
| | - Zulong Liu
- Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, Lexington, KY, 40536, USA
| | - Aditi Jain
- Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, Lexington, KY, 40536, USA.,The Jefferson Pancreas, Biliary and Related Cancer Center, Department of Surgery, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, USA
| | - Anastasia Lyon
- Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, Lexington, KY, 40536, USA
| | - Christina Meeks
- Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, Lexington, KY, 40536, USA
| | - Dana Richards
- Department of Pathology, University of Kentucky College of Medicine, Lexington, KY, 40536, USA
| | - Jinpeng Liu
- Biostatistics and Bioinformatics Shared Resource Facility, Markey Cancer Center, University of Kentucky College of Medicine, Lexington, KY, 40536, USA
| | - Daheng He
- Biostatistics and Bioinformatics Shared Resource Facility, Markey Cancer Center, University of Kentucky College of Medicine, Lexington, KY, 40536, USA
| | - Chi Wang
- Biostatistics and Bioinformatics Shared Resource Facility, Markey Cancer Center, University of Kentucky College of Medicine, Lexington, KY, 40536, USA
| | | | | | - Peng Wang
- Department of Internal Medicine, University of Kentucky, College of Medicine, Lexington, KY, USA
| | - Melissa Wilson
- Department of Medical Oncology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, USA
| | - Rina Plattner
- Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, Lexington, KY, 40536, USA.
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5
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Schivo S, Scholma J, van der Vet PE, Karperien M, Post JN, van de Pol J, Langerak R. Modelling with ANIMO: between fuzzy logic and differential equations. BMC SYSTEMS BIOLOGY 2016; 10:56. [PMID: 27460034 PMCID: PMC4962523 DOI: 10.1186/s12918-016-0286-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 06/02/2016] [Indexed: 11/23/2022]
Abstract
BACKGROUND Computational support is essential in order to reason on the dynamics of biological systems. We have developed the software tool ANIMO (Analysis of Networks with Interactive MOdeling) to provide such computational support and allow insight into the complex networks of signaling events occurring in living cells. ANIMO makes use of timed automata as an underlying model, thereby enabling analysis techniques from computer science like model checking. Biology experts are able to use ANIMO via a user interface specifically tailored for biological applications. In this paper we compare the use of ANIMO with some established formalisms on two case studies. RESULTS ANIMO is a powerful and user-friendly tool that can compete with existing continuous and discrete paradigms. We show this by presenting ANIMO models for two case studies: Drosophila melanogaster circadian clock, and signal transduction events downstream of TNF α and EGF in HT-29 human colon carcinoma cells. The models were originally developed with ODEs and fuzzy logic, respectively. CONCLUSIONS Two biological case studies that have been modeled with respectively ODE and fuzzy logic models can be conveniently modeled using ANIMO. The ANIMO models require less parameters than ODEs and are more precise than fuzzy logic. For this reason we position the modelling paradigm of ANIMO between ODEs and fuzzy logic.
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Affiliation(s)
- Stefano Schivo
- Formal Methods and Tools, Faculty of EEMCS, University of Twente, P.O. Box 217, Enschede, 7500AE, The Netherlands
| | - Jetse Scholma
- Developmental BioEngineering, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, P.O. Box 217, Enschede, 7500AE, The Netherlands
| | - Paul E van der Vet
- Human Media Interaction, Faculty of EEMCS, University of Twente, P.O. Box 217, Enschede, 7500AE, The Netherlands
| | - Marcel Karperien
- Developmental BioEngineering, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, P.O. Box 217, Enschede, 7500AE, The Netherlands
| | - Janine N Post
- Developmental BioEngineering, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, P.O. Box 217, Enschede, 7500AE, The Netherlands
| | - Jaco van de Pol
- Formal Methods and Tools, Faculty of EEMCS, University of Twente, P.O. Box 217, Enschede, 7500AE, The Netherlands
| | - Rom Langerak
- Formal Methods and Tools, Faculty of EEMCS, University of Twente, P.O. Box 217, Enschede, 7500AE, The Netherlands.
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6
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Liu C, Wang S, Zhu S, Wang H, Gu J, Gui Z, Jing J, Hou X, Shao Y. MAP3K1-targeting therapeutic artificial miRNA suppresses the growth and invasion of breast cancer in vivo and in vitro. SPRINGERPLUS 2016; 5:11. [PMID: 26759750 PMCID: PMC4700027 DOI: 10.1186/s40064-015-1597-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 12/07/2015] [Indexed: 01/11/2023]
Abstract
Recent investigations have highlighted that therapeutic artificial microRNAs could be promising candidates for cancer therapy through the modulation of tumor promoter or suppressor. MEK kinase 1 (MEKK1) is expressed by mitogen-activated kinase kinase kinase 1 (MAP3K1), an important kinase that links Ras activation to MAPK signaling. In the present study, we showed that synthetic MAP3K1-targeting artificial miRNA may provide considerable beneficial effects in the prevention of breast cancer growth and metastasis. We showed that MEKK1 was highly expressed in human breast cancer specimens, compared with adjacent normal tissues. Using a miRNA-expressing lentivirus system, we delivered a artificial miRNA (Map3k1 amiRNA) that targets MAP3K1 into 4T1 breast cancer cells and investigated the impact of MAP3K1-targeting miRNA on the growth and invasive behavior of breast cancer in vitro and in vivo. We found that overexpression of Map3k1 amiRNA led to impaired activities of p-ERK and p-p38. In addition, Map3k1 amiRNA induced marked proliferative impairment and invasive attenuation in breast cancer cells. However, Map3k1 amiRNA did not have evident influence on the apoptotic response of 4T1 cells. Moreover, using in vivo nude mice model, we identified that Map3k1 amiRNA attenuated tumor growth and lung metastasis of breast cancer cells. Taken together, our findings explicitly indicated that MEKK1 exerted important oncogenic property in breast cancer development, and MAP3K1-targeting artificial miRNA may provide promising therapeutic effects in the treatment of breast cancer.
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Affiliation(s)
- Chun Liu
- Laboratory animal center of Nantong University, 19 Qixiu Road, Nantong, Jiangsu People's Republic of China
| | - Shengjie Wang
- Kangda College of Nanjing Medical University, 88 Chunhui Road, Lianyungang, Jiangsu People's Republic of China
| | - Shunxing Zhu
- Laboratory animal center of Nantong University, 19 Qixiu Road, Nantong, Jiangsu People's Republic of China
| | - Haifeng Wang
- Kangda College of Nanjing Medical University, 88 Chunhui Road, Lianyungang, Jiangsu People's Republic of China
| | - Jiayi Gu
- Laboratory animal center of Nantong University, 19 Qixiu Road, Nantong, Jiangsu People's Republic of China
| | - Zeping Gui
- Laboratory animal center of Nantong University, 19 Qixiu Road, Nantong, Jiangsu People's Republic of China
| | - Jin Jing
- Laboratory animal center of Nantong University, 19 Qixiu Road, Nantong, Jiangsu People's Republic of China
| | - Xiaofan Hou
- Laboratory animal center of Nantong University, 19 Qixiu Road, Nantong, Jiangsu People's Republic of China
| | - Yixiang Shao
- Laboratory animal center of Nantong University, 19 Qixiu Road, Nantong, Jiangsu People's Republic of China
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7
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Garant KA, Shmulevitz M, Pan L, Daigle RM, Ahn DG, Gujar SA, Lee PWK. Oncolytic reovirus induces intracellular redistribution of Ras to promote apoptosis and progeny virus release. Oncogene 2015; 35:771-82. [PMID: 25961930 DOI: 10.1038/onc.2015.136] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Revised: 02/13/2015] [Accepted: 03/27/2015] [Indexed: 11/09/2022]
Abstract
Reovirus is a naturally oncolytic virus that preferentially replicates in Ras-transformed cells and is currently undergoing clinical trials as a cancer therapeutic. Ras transformation promotes reovirus oncolysis by enhancing virion disassembly during entry, viral progeny production, and virus release through apoptosis; however, the mechanism behind the latter is not well understood. Here, we show that reovirus alters the intracellular location of oncogenic Ras to induce apoptosis of H-RasV12-transformed fibroblasts. Reovirus infection decreases Ras palmitoylation levels and causes accumulation of Ras in the Golgi through Golgi fragmentation. With the Golgi being the site of Ras palmitoylation, treatment of target cells with the palmitoylation inhibitor, 2-bromopalmitate (2BP), prompts a greater accumulation of H-RasV12 in the Golgi, and a dose-dependent increase in progeny virus release and subsequent spread. Conversely, tethering H-RasV12 to the plasma membrane (thereby preventing its movement to the Golgi) allows for efficient virus production, but results in basal levels of reovirus-induced cell death. Analysis of Ras downstream signaling reveals that cells expressing cycling H-RasV12 have elevated levels of phosphorylated JNK (c-Jun N-terminal kinase), and that Ras retained at the Golgi body by 2BP increases activation of the MEKK1/MKK4/JNK signaling pathway to promote cell death. Collectively, our data suggest that reovirus induces Golgi fragmentation of target cells, and the subsequent accumulation of oncogenic Ras in the Golgi body initiates apoptotic signaling events required for virus release and spread.
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Affiliation(s)
- K A Garant
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS, Canada
| | - M Shmulevitz
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB, Canada
| | - L Pan
- Division of Fundamental Neurobiology, Toronto Western Research Institute, Toronto, ON, Canada
| | - R M Daigle
- Department of Oceanography, Dalhousie University, Halifax, NS, Canada
| | - D-G Ahn
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS, Canada
| | - S A Gujar
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS, Canada.,Strategy and Organizational Performance, IWK Health Centre, Halifax, NS, Canada
| | - P W K Lee
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS, Canada.,Department of Pathology, Dalhousie University, Halifax, NS, Canada
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8
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Suddason T, Gallagher E. A RING to rule them all? Insights into the Map3k1 PHD motif provide a new mechanistic understanding into the diverse roles of Map3k1. Cell Death Differ 2015; 22:540-8. [PMID: 25613373 PMCID: PMC4356348 DOI: 10.1038/cdd.2014.239] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2014] [Revised: 12/15/2014] [Accepted: 12/17/2014] [Indexed: 12/26/2022] Open
Abstract
Despite the sizable number of components that comprise Mapk cascades, Map3k1 is the only element that contains both a kinase domain and a plant homeodomain (PHD) motif, allowing Map3k1 to regulate the protein phosphorylation and ubiquitin proteasome systems. As such, Map3k1 has complex roles in the regulation of cell death, survival, migration and differentiation. Numerous mouse and human genetic analyses have demonstrated that Map3k1 is of critical importance for the immune system, cardiac tissue, testis, wound healing, tumorigenesis and cancer. Recent gene knockin of Map3k1 to mutate the E2 binding site within the Map3k1 PHD motif and high throughput ubiquitin protein array screening for Map3k1 PHD motif substrates provide critical novel insights into Map3k1 PHD motif signal transduction and bring a brand-new understanding to Map3k1 signaling in mammalian biology.
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Affiliation(s)
- T Suddason
- Department of Medicine, Imperial College London, Du Cane Road, London, UK
| | - E Gallagher
- Department of Medicine, Imperial College London, Du Cane Road, London, UK
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9
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Engelberg D, Perlman R, Levitzki A. Transmembrane signaling in Saccharomyces cerevisiae as a model for signaling in metazoans: state of the art after 25 years. Cell Signal 2014; 26:2865-78. [PMID: 25218923 DOI: 10.1016/j.cellsig.2014.09.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Accepted: 09/02/2014] [Indexed: 02/07/2023]
Abstract
In the very first article that appeared in Cellular Signalling, published in its inaugural issue in October 1989, we reviewed signal transduction pathways in Saccharomyces cerevisiae. Although this yeast was already a powerful model organism for the study of cellular processes, it was not yet a valuable instrument for the investigation of signaling cascades. In 1989, therefore, we discussed only two pathways, the Ras/cAMP and the mating (Fus3) signaling cascades. The pivotal findings concerning those pathways undoubtedly contributed to the realization that yeast is a relevant model for understanding signal transduction in higher eukaryotes. Consequently, the last 25 years have witnessed the discovery of many signal transduction pathways in S. cerevisiae, including the high osmotic glycerol (Hog1), Stl2/Mpk1 and Smk1 mitogen-activated protein (MAP) kinase pathways, the TOR, AMPK/Snf1, SPS, PLC1 and Pkr/Gcn2 cascades, and systems that sense and respond to various types of stress. For many cascades, orthologous pathways were identified in mammals following their discovery in yeast. Here we review advances in the understanding of signaling in S. cerevisiae over the last 25 years. When all pathways are analyzed together, some prominent themes emerge. First, wiring of signaling cascades may not be identical in all S. cerevisiae strains, but is probably specific to each genetic background. This situation complicates attempts to decipher and generalize these webs of reactions. Secondly, the Ras/cAMP and the TOR cascades are pivotal pathways that affect all processes of the life of the yeast cell, whereas the yeast MAP kinase pathways are not essential. Yeast cells deficient in all MAP kinases proliferate normally. Another theme is the existence of central molecular hubs, either as single proteins (e.g., Msn2/4, Flo11) or as multisubunit complexes (e.g., TORC1/2), which are controlled by numerous pathways and in turn determine the fate of the cell. It is also apparent that lipid signaling is less developed in yeast than in higher eukaryotes. Finally, feedback regulatory mechanisms seem to be at least as important and powerful as the pathways themselves. In the final chapter of this essay we dare to imagine the essence of our next review on signaling in yeast, to be published on the 50th anniversary of Cellular Signalling in 2039.
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Affiliation(s)
- David Engelberg
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, 91904 Jerusalem, Israel; CREATE-NUS-HUJ, Cellular & Molecular Mechanisms of Inflammation Programme, National University of Singapore, 1 CREATE Way, Innovation Wing, #03-09, Singapore 138602, Singapore.
| | - Riki Perlman
- Hematology Division, Hadassah Hebrew University Medical Center, POB 12000, 91120 Jerusalem, Israel
| | - Alexander Levitzki
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, 91904 Jerusalem, Israel
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10
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CSNK1α1 mediates malignant plasma cell survival. Leukemia 2014; 29:474-82. [PMID: 24962017 DOI: 10.1038/leu.2014.202] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Revised: 05/12/2014] [Accepted: 05/19/2014] [Indexed: 12/18/2022]
Abstract
Here we report that targeting casein kinase 1-α1 (CSNK1α1) is a potential novel treatment strategy in multiple myeloma (MM) therapy distinct from proteasome inhibition. CSNK1α1 is expressed in all the tested MM cell lines and patient MM cells, and is not altered during bortezomib-triggered cytotoxicity. Inhibition of CSNK1α1 kinase activity in MM cells with targeted therapy D4476 or small hairpin RNAs triggers cell G0/G1-phase arrest, prolonged G2/M phase and apoptosis. D4476 also induced cytotoxicity in bortezomib-resistant MM cells and enhanced bortezomib-triggered cytotoxicity. CSNK1α1 signaling pathways include CDKN1B, P53 and FADD; gene signatures involved included interferon-α, tumor necrosis factor-α and LIN9. In addition, reduction of Csnk1α1 prevents cMYC/KRAS12V transformation of BaF3 cells independent of interleukin-3. Impartially, reducing Csnk1α1 prevented development of cMYC/KRAS12V-induced plasmacytomas in mice, suggesting that CSNK1α1 may be involved in MM initiation and progression. Our data suggest that targeting CSNK1α1, alone or combined with bortezomib, is a potential novel therapeutic strategy in MM. Moreover, inhibition of CSNK1α1 may prevent the progression of monoclonal gammopathy of undetermined significance to MM.
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11
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12
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Pham TT, Angus SP, Johnson GL. MAP3K1: Genomic Alterations in Cancer and Function in Promoting Cell Survival or Apoptosis. Genes Cancer 2014; 4:419-26. [PMID: 24386504 DOI: 10.1177/1947601913513950] [Citation(s) in RCA: 94] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2013] [Accepted: 11/02/2013] [Indexed: 12/15/2022] Open
Abstract
MAP3K1 is a member of the mitogen-activated protein kinase kinase kinase (MAP3K) family of serine/threonine kinases. MAP3K1 regulates JNK activation and is unique among human kinases in that it also encodes an E3 ligase domain that ubiquitylates c-Jun and ERK1/2. Full length MAP3K1 regulates cell migration and contributes to pro-survival signaling while its caspase 3-mediated cleavage generates a C-terminal kinase domain that promotes apoptosis. The critical function of MAP3K1 in cell fate decisions suggests that it may be a target for deregulation in cancer. Recent large-scale genomic studies have revealed that MAP3K1 copy number loss and somatic missense or nonsense mutations are observed in a significant number of different cancers, being most prominent in luminal breast cancer. The alteration of MAP3K1 in diverse cancer types demonstrates the importance of defining phenotypes for possible therapeutic targeting of tumor cell vulnerabilities created when MAP3K1 function is lost or gained.
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Affiliation(s)
- Trang T Pham
- Department of Pharmacology, Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | - Steven P Angus
- Department of Pharmacology, Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | - Gary L Johnson
- Department of Pharmacology, Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC, USA
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13
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Abstract
Wdr68 is a highly conserved scaffolding protein required for craniofacial development and left-right asymmetry. A Ras-Map3k-Wdr68-Dyrk1 signaling relay may mediate these and other diverse signaling events important in development and disease. While the sub-cellular localization of Wdr68 has been shown to be dependent on that of its interaction partners, it is not clear where Wdr68 activity is required during development. Here we show that while a GFP-Wdr68 fusion functionally substituted for craniofacial development in the zebrafish, that a Nuclear Export Signal (NES) fusion protein (GFPNESWdr68) failed to support craniofacial development. As control for NES activity, we show that while GFP-Wdr68 exhibited a pan-cellular distribution in C2C12 cells, the GFPNESWdr68 fusion predominantly localized to the cell cytoplasm, as expected. Interestingly, while GFP-Wdr68 and RFP-Dyrk1a co-localized to the cell nucleus as expected based on the known sub-cellular localization for Dyrk1a, we found that the GFPNESWdr68 fusion redistributed RFP-Dyrk1a to the cell cytoplasm potentially disconnecting the Ras/Dyrk1 signal relay from further downstream targets. Consistent with a nuclear role in gene regulation, we also found that while a transcriptional activation domain fusion, CebpFlagWdr68, functionally substituted for endogenous Wdr68 for craniofacial development, that a transcriptional repression domain fusion, MadFlagWdr68, failed to support craniofacial development. Dyrk1b is required for myogenin (myog) expression in differentiating mouse C2C12 cells and here we report that wdr68 is also important for myog expression in differentiating C2C12 cells. Using a C2C12 cell myog promoter-reporter system, we found that Wdr68 overexpression increased reporter activity while moderate expression levels of MadFlagWdr68 interfered with reporter activity. Taken together, these findings support a nuclear role for Wdr68-containing complexes.
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Ras and Rap1 govern spatiotemporal dynamic of activated ERK in pituitary living cells. Cell Signal 2012; 24:2237-48. [PMID: 22940095 DOI: 10.1016/j.cellsig.2012.08.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Revised: 08/02/2012] [Accepted: 08/14/2012] [Indexed: 11/22/2022]
Abstract
The Ras/Raf/MEK/ERK is a conserved signalling pathway involved in the control of fundamental cellular processes. Despite extensive research, how this pathway can process a myriad of diverse extracellular inputs into substrate specificity to determine biological outcomes is not fully understood. It has been established that the ERK1/2 pathway is an integrative point in the control of the pituitary function exerted by various extracellular signals. In addition we previously established that the GTPases Ras and Rap1 play a key role in the regulation of ERK1/2-dependent prolactin transcription by EGF or the cAMP-dependent neuropeptide VIP. In this report, using the FRET-based biosensor of ERK activity (EKAR) in the pituitary GH4C1 cell line, we show that both EGF and VIP tightly control the spatiotemporal dynamic of activated ERK with different magnitude and duration. Importantly, we provide the first evidence of a differential control of cytoplasmic and nuclear pools of activated ERK by the GTPases Ras and Rap1. Ras is required for nuclear magnitude and duration of EGF-dependent ERK activation, whereas it is required for both VIP-activated cytoplasmic and nuclear ERK pools. Rap1 is exclusively involved in VIP-activated ERK nuclear pool. Moreover, consistent with the control of the nuclear pool of activated ERK by the GTPases, we observe the same differential role of Ras and Rap1 on ERK nuclear translocation triggered by EGF or VIP. Together these findings identify Ras and Rap1 as determinant partners in shaping nuclear and cytoplasmic ERK kinetics in response to EGF and VIP, which in turn should control pituitary secretion.
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15
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Kubota Y, O'Grady P, Saito H, Takekawa M. Oncogenic Ras abrogates MEK SUMOylation that suppresses the ERK pathway and cell transformation. Nat Cell Biol 2011; 13:282-91. [PMID: 21336309 DOI: 10.1038/ncb2169] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2010] [Accepted: 11/30/2010] [Indexed: 12/11/2022]
Abstract
The ERK (extracellular signal-regulated kinase) MAPK (mitogen-activated protein kinase) cascade (Raf-MEK-ERK) mediates mitogenic signalling, and is frequently hyperactivated by Ras oncogenes in human cancer. The entire range of activities of multifunctional Ras in carcinogenesis remains elusive. Here we report that the ERK pathway is downregulated by MEK (MAPK-ERK kinase) SUMOylation, which is inhibited by oncogenic Ras. MEK SUMOylation blocked ERK activation by disrupting the specific docking interaction between MEK and ERK. Expression of un-SUMOylatable MEK enhanced ERK activation, cell differentiation, proliferation and malignant transformation by oncogenic ErbB2 or Raf, but not by active Ras. Interestingly, MEK SUMOylation was abrogated in cancer cells harbouring Ras mutations. Oncogenic Ras inhibits MEK SUMOylation by impairing the function of the MEKK1 MAPKKK as a SUMO-E3 ligase specific for MEK. Furthermore, forced enhancement of MEK SUMOylation suppressed Ras-induced cell transformation. Thus, oncogenic Ras efficiently activates the ERK pathway both by activating Raf and by inhibiting MEK SUMOylation, thereby inducing carcinogenesis.
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Affiliation(s)
- Yuji Kubota
- Department of Molecular Cell Signaling, Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Tokyo 108-8639, Japan
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16
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Ritterhoff S, Farah CM, Grabitzki J, Lochnit G, Skurat AV, Schmitz ML. The WD40-repeat protein Han11 functions as a scaffold protein to control HIPK2 and MEKK1 kinase functions. EMBO J 2010; 29:3750-61. [PMID: 20940704 PMCID: PMC2989105 DOI: 10.1038/emboj.2010.251] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2010] [Accepted: 09/17/2010] [Indexed: 12/18/2022] Open
Abstract
Protein kinases are organized in hierarchical networks that are assembled and regulated by scaffold proteins. Here, we identify the evolutionary conserved WD40-repeat protein Han11 as an interactor of the kinase homeodomain-interacting protein kinase 2 (HIPK2). In vitro experiments showed the direct binding of Han11 to HIPK2, but also to the kinases DYRK1a, DYRK1b and mitogen-activated protein kinase kinase kinase 1 (MEKK1). Han11 was required to allow coupling of MEKK1 to DYRK1 and HIPK2. Knockdown experiments in Caenorhabditis elegans showed the relevance of the Han11 orthologs Swan-1 and Swan-2 for the osmotic stress response. Downregulation of Han11 in human cells lowered the threshold and amplitude of HIPK2- and MEKK1-triggered signalling events and changed the kinetics of kinase induction. Han11 knockdown changed the amplitude and time dependence of HIPK2-driven transcription in response to DNA damage and also interfered with MEKK1-triggered gene expression and stress signalling. Impaired signal transmission also occurred upon interference with stoichiometrically assembled signalling complexes by Han11 overexpression. Collectively, these experiments identify Han11 as a novel scaffold protein regulating kinase signalling by HIPK2 and MEKK1.
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Affiliation(s)
- Stefanie Ritterhoff
- Institute of Biochemistry, Medical Faculty, Justus-Liebig-University, Giessen, Germany
| | - Carla M Farah
- Institute of Biochemistry, Medical Faculty, Justus-Liebig-University, Giessen, Germany
| | - Julia Grabitzki
- Institute of Biochemistry, Medical Faculty, Justus-Liebig-University, Giessen, Germany
| | - Günter Lochnit
- Institute of Biochemistry, Medical Faculty, Justus-Liebig-University, Giessen, Germany
| | - Alexander V Skurat
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, USA
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17
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Discrete logic modelling as a means to link protein signalling networks with functional analysis of mammalian signal transduction. Mol Syst Biol 2009; 5:331. [PMID: 19953085 PMCID: PMC2824489 DOI: 10.1038/msb.2009.87] [Citation(s) in RCA: 278] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2009] [Accepted: 10/28/2009] [Indexed: 01/13/2023] Open
Abstract
Large-scale protein signalling networks are useful for exploring complex biochemical pathways but do not reveal how pathways respond to specific stimuli. Such specificity is critical for understanding disease and designing drugs. Here we describe a computational approach—implemented in the free CNO software—for turning signalling networks into logical models and calibrating the models against experimental data. When a literature-derived network of 82 proteins covering the immediate-early responses of human cells to seven cytokines was modelled, we found that training against experimental data dramatically increased predictive power, despite the crudeness of Boolean approximations, while significantly reducing the number of interactions. Thus, many interactions in literature-derived networks do not appear to be functional in the liver cells from which we collected our data. At the same time, CNO identified several new interactions that improved the match of model to data. Although missing from the starting network, these interactions have literature support. Our approach, therefore, represents a means to generate predictive, cell-type-specific models of mammalian signalling from generic protein signalling networks.
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18
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Proteinase-activated receptor 2 expression in breast cancer and its role in breast cancer cell migration. Oncogene 2009; 28:3047-57. [PMID: 19543320 DOI: 10.1038/onc.2009.163] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Proteinase-activated receptor 2 (PAR2) is a G protein-coupled receptor that is activated by trypsin-like proteinases. PAR2 is detected in breast tumor specimens; however, it is not clear how PAR2 level in breast cancer cell/tissues compares with normal cell/tissues. Here, we show the elevation of PAR2 protein level in 76 of 105 breast tumor specimens but only 5 of 24 normal breast tissues. PAR2 level is also higher in breast cancer cell lines than that in normal breast cells and non-cancerous breast cell lines. To determine the role of PAR2 in breast carcinogenesis, we examined the effect of PAR2 agonists on cell proliferation and migration. Our studies show that PAR2 agonists (PAR2-activating peptide and trypsin) are neither potent growth enhancers nor chemoattractants to breast cancer cells. Instead, PAR2 agonists induce significant chemokinesis. PAR2-mediated chemokinesis is G(alphai)-dependent, and inhibiting Src kinase activity or silencing c-Src expression blocks PAR2-mediated chemokinesis. These results suggest that c-Src works downstream of G(alphai) to mediate this PAR2 agonist-induced event. To characterize c-Src effector, we reveal that PAR2 agonists activate JNKs in a Src-dependent manner and that JNK activity is essential for PAR2-mediated chemokinesis. Moreover, PAR2 agonist stimulation leads to paxillin Ser(178) phosphorylation and paxillin(S178A) mutant inhibits PAR2-mediated chemokinesis. In conclusion, our studies show that PAR2 agonists facilitate breast cancer cell chemokinesis through the G(alphai)-c-Src-JNK-paxillin signaling pathway.
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19
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Ung CY, Li H, Ma XH, Jia J, Li BW, Low BC, Chen YZ. Simulation of the regulation of EGFR endocytosis and EGFR-ERK signaling by endophilin-mediated RhoA-EGFR crosstalk. FEBS Lett 2008; 582:2283-90. [PMID: 18505685 DOI: 10.1016/j.febslet.2008.05.026] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2008] [Revised: 04/28/2008] [Accepted: 05/16/2008] [Indexed: 12/24/2022]
Abstract
Deregulations of EGFR endocytosis in EGFR-ERK signaling are known to cause cancers and developmental disorders. Mutations that impaired c-Cbl-EGFR association delay EGFR endocytosis and produce higher mitogenic signals in lung cancer. ROCK, an effector of small GTPase RhoA was shown to negatively regulate EGFR endocytosis via endophilin A1. A mathematical model was developed to study how RhoA and ROCK regulate EGFR endocytosis. Our study suggested that over-expressing RhoA as well as ROCK prolonged ERK activation partly by reducing EGFR endocytosis. Overall, our study hypothesized an alternative role of RhoA in tumorigenesis in addition to its regulation of cytoskeleton and cell motility.
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Affiliation(s)
- Choong Yong Ung
- Bioinformatics and Drug Design Group, Department of Pharmacy, National University of Singapore, 3 Science Drive 2, Singapore 117543, Singapore
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20
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Lee JY, Park HR, Oh YK, Kim YJ, Youn J, Han JS, Kim JM. Effects of transcription factor activator protein-1 on interleukin-8 expression and enteritis in response to Clostridium difficile toxin A. J Mol Med (Berl) 2007; 85:1393-404. [PMID: 17639289 DOI: 10.1007/s00109-007-0237-7] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2007] [Revised: 06/01/2007] [Accepted: 06/12/2007] [Indexed: 02/07/2023]
Abstract
Clostridium difficile toxin A causes acute colitis associated with intense infiltration of neutrophils. Although C. difficile toxin A is known to induce nuclear factor-kappaB-mediated chemokine expression in intestinal epithelial cells, little is known about its effect on the regulation of activator protein-1 (AP-1) by mitogen-activated protein kinase (MAPK). In the present study, we investigated whether the MAPK and AP-1 signaling pathway is involved in interleukin (IL)-8 expression and enteric inflammation in response to stimulation with toxin A. Toxin A activated MAPK and AP-1 composed of c-Jun/c-Fos heterodimers in primary intestinal epithelial cells and HT-29 cell lines. Transfection with mutant genes for Ras, c-Jun, p38, or c-Jun N-terminal kinase (JNK) significantly inhibited C. difficile toxin A-induced activation of AP-1 and expression of IL-8 in HT-29 cell lines. Furthermore, the p38 inhibitor SB203580 attenuated toxin A-induced inflammation in vivo in the mouse ileum, evidenced by a significant decrease in neutrophil infiltration, villous destruction, and mucosal congestion. Our results suggest that the Ras/MAPK cascade acts as the upstream signaling for AP-1 activation and IL-8 expression in toxin A-stimulated intestinal epithelial cells and may be involved in the development of enteritis after infection with toxin A-producing C. difficile.
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Affiliation(s)
- Jin Young Lee
- Department of Microbiology and Institute of Biomedical Science, Hanyang University College of Medicine, Seoul, 133-791, South Korea
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21
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Abstract
Mitogen-activated protein kinases (MAPKs) regulate critical signaling pathways involved in cell proliferation, differentiation and apoptosis. Recent studies have shown that a novel class of scaffold proteins mediates the structural and functional organization of the three-tier MAPK module. By linking the MAP3K, MAP2K and MAPK into a multienzyme complex, these MAPK-specific scaffold proteins provide an insulated physical conduit through which signals from the respective MAPK can be transmitted to the appropriate spatiotemporal cellular loci. Scaffold proteins play a determinant role in modulating the signaling strength of their cognate MAPK module by regulating the signal amplitude and duration. The scaffold proteins themselves are finely regulated resulting in dynamic intra- and inter-molecular interactions that can modulate the signaling outputs of MAPK modules. This review focuses on defining the diverse mechanisms by which these scaffold proteins interact with their respective MAPK modules and the role of such interactions in the spatiotemporal organization as well as context-specific signaling of the different MAPK modules.
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Affiliation(s)
- D N Dhanasekaran
- Fels Institute for Cancer Research and Molecular Biology, Temple University School of Medicine, Philadelphia, PA 19140, USA
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22
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Furukawa M, Ebmeyer J, Pak K, Austin DA, Melhus A, Webster NJG, Ryan AF. Jun N-terminal protein kinase enhances middle ear mucosal proliferation during bacterial otitis media. Infect Immun 2007; 75:2562-71. [PMID: 17325051 PMCID: PMC1865762 DOI: 10.1128/iai.01656-06] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Mucosal hyperplasia is a characteristic component of otitis media. The present study investigated the participation of signaling via the Jun N-terminal protein kinase (JNK) mitogen-activated protein kinase in middle ear mucosal hyperplasia in animal models of bacterial otitis media. Otitis media was induced by the inoculation of nontypeable Haemophilus influenzae into the middle ear cavity. Western blotting revealed that phosphorylation of JNK isoforms in the middle ear mucosa preceded but paralleled mucosal hyperplasia in this in vivo rat model. Nuclear JNK phosphorylation was observed in many cells of both the mucosal epithelium and stroma by immunohistochemistry. In an in vitro model of primary rat middle ear mucosal explants, bacterially induced mucosal growth was blocked by the Rac/Cdc42 inhibitor Clostridium difficile toxin B, the mixed-lineage kinase inhibitor CEP11004, and the JNK inhibitor SP600125. Finally, the JNK inhibitor SP600125 significantly inhibited mucosal hyperplasia during in vivo bacterial otitis media in guinea pigs. Inhibition of JNK in vivo resulted in a diminished proliferative response, as shown by a local decrease in proliferating cell nuclear antigen protein expression by immunohistochemistry. We conclude that activation of JNK is a critical pathway for bacterially induced mucosal hyperplasia during otitis media, influencing tissue proliferation.
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Affiliation(s)
- Masayuki Furukawa
- Department of Surgery, UCSD School of Medicine, Fir Bldg., Rm. 106, 9500 Gilman Dr. #0666, La Jolla, CA 92037, USA
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23
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Kim YJ, Hwang SY, Oh ES, Oh S, Han IO. IL-1beta, an immediate early protein secreted by activated microglia, induces iNOS/NO in C6 astrocytoma cells through p38 MAPK and NF-kappaB pathways. J Neurosci Res 2006; 84:1037-46. [PMID: 16881054 DOI: 10.1002/jnr.21011] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In the present study we sought to examine cell-cell interactions by investigating the effects of factors released by stimulated microglia on inducible nitric oxide (NO) synthase (iNOS) induction in astrocytoma cells. After examining the temporal profiles of proinflammatory molecules induced by lipopolysaccharide (LPS) stimulation in BV2 microglial cells, iNOS and IL-1beta were observed to be the first immediate-response molecules. Removal of LPS after 3 hr stimulation abrogated NO release, whereas a full induction of IL-1beta was retained in BV2 cells. We observed consistently that conditioned medium (CM) from activated microglia resulted in the induction of iNOS in C6 cells, and IL-1beta was shown to be a key regulator of iNOS induction. An IL-1beta-neutralizing antibody diminished NO induction. Incubation with recombinant IL-1beta stimulated NO release to a lesser extent compared to microglial CM; co-treatment of LPS and IL-1beta had a potent, synergistic effect on NO release from C6 cells. Transient transfection with MEK kinase 1 (MEKK1) or nuclear factor-kappa B (NF-kappaB) expression plasmids induced iNOS, and IL-1beta further enhanced the MEKK1 response. Furthermore, IL-1beta-mediated NO release from C6 cells was significantly suppressed by inhibition of p38 mitogen activated protein kinase (MAPK) or NF-kappaB by specific chemical inhibitors. Both IL-1beta and MEKK1 stimulated p38 and JNK MAPKs, as well as the NF-kappaB pathway, to induce iNOS in C6 cells. Microglia may represent an anti-tumor response in the central nervous system, which is potentiated by the local secretion of immunomodulatory factors that in turn affects astrocytoma (glioma) cells. A better understanding of microglia-glioma or microglia-astrocyte interactions will help in the design of novel immune-based therapies for brain tumors or neuronal diseases.
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Affiliation(s)
- Yun-Jung Kim
- Department of Physiology and Biophysics, and Center for Advanced Medical Education by BK21 Project, Inha University, College of Medicine, Incheon, Korea
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24
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Kim JM, Jung HY, Lee JY, Youn J, Lee CH, Kim KH. Mitogen-activated protein kinase and activator protein-1 dependent signals are essential for Bacteroides fragilis enterotoxin-induced enteritis. Eur J Immunol 2005; 35:2648-57. [PMID: 16114110 DOI: 10.1002/eji.200526321] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The approximately 20-kDa heat-labile toxin produced by enterotoxigenic Bacteroides fragilis is known to be associated with the development of enteritis. However, the molecular mechanism involved is not yet fully understood. In this study, we assessed whether B. fragilis enterotoxin (BFT)-induced enteritis is related to mitogen-activated protein kinase (MAPK) signaling pathways. In human colon epithelial cells, BFT activated three major MAPK cascades. The activation of p38 was sustained for a relatively long period, while the stimulation of extracellular signal-regulated kinases (ERK) and c-Jun N-terminal kinase (JNK) was transient. BFT stimulation also activated AP-1 signals composed of c-Jun/c-Fos heterodimers. The p38 inhibitor SB203580 and the ERK inhibitor U0126 reduced not only AP-1 activity, but also decreased IL-8 and MCP-1 expression. In addition, the overexpression of superrepressors for c-Jun and Ras induced by BFT stimulation decreased the levels of IL-8 and MCP-1 production. Furthermore, SB203580 prevented BFT-induced colitis in the mouse ileum, as evidenced by significant decreases in villous destruction, neutrophil infiltration, and mucosal congestion. These results suggest that a pathway, including Ras, MAPK, and subsequent AP-1 activation, is required for IL-8 and MCP-1 expression in intestinal epithelial cells exposed to BFT, and can be involved in the development of enteritis.
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Affiliation(s)
- Jung Mogg Kim
- Department of Microbiology and Institute of Biomedical Science, Hanyang University College of Medicine, Seoul, Korea.
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25
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Friday BB, Adjei AA. K-ras as a target for cancer therapy. Biochim Biophys Acta Rev Cancer 2005; 1756:127-44. [PMID: 16139957 DOI: 10.1016/j.bbcan.2005.08.001] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2005] [Revised: 07/29/2005] [Accepted: 08/01/2005] [Indexed: 11/30/2022]
Abstract
The central role K-, H- and N-Ras play in regulating diverse cellular pathways important for cell growth, differentiation and survival is well established. Dysregulation of Ras proteins by activating mutations, overexpression or upstream activation is common in human tumors. Of the Ras proteins, K-ras is the most frequently mutated and is therefore an attractive target for cancer therapy. The complexity of K-ras signaling presents many opportunities for therapeutic targeting. A number of different approaches aimed at abrogating K-ras activity have been explored in clinical trials. Several of the therapeutic agents tested have demonstrated clinical activity, supporting ongoing development of K-ras targeted therapies. However, many of the agents currently being evaluated have multiple targets and their antitumor effects may not be due to K-Ras inhibition. To date, no selective, specific inhibitor of K-ras is available for routine clinical use. In this review, we will summarize the structure and function of K-ras with attention to its role in tumorigenesis and discuss the successes and failures of the various strategies designed to therapeutically target this important oncogene.
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Affiliation(s)
- Bret B Friday
- Division of Medical Oncology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA.
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26
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Li H, Ye X, Mahanivong C, Bian D, Chun J, Huang S. Signaling mechanisms responsible for lysophosphatidic acid-induced urokinase plasminogen activator expression in ovarian cancer cells. J Biol Chem 2005; 280:10564-71. [PMID: 15653692 DOI: 10.1074/jbc.m412152200] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Lysophosphatidic acid (LPA) enhances urokinase plasminogen activator (uPA) expression in ovarian cancer cells; however, the molecular mechanisms responsible for this event have not been investigated. In this study, we used the invasive ovarian cancer SK-OV-3 cell line to explore the signaling molecules and pathways essential for LPA-induced uPA up-regulation. With the aid of specific inhibitors and dominant negative forms of signaling molecules, we determined that the G(i)-associated pathway mediates this LPA-induced event. Moreover, constitutively active H-Ras and Raf-1-activating H-Ras mutant enhance uPA expression, whereas dominant negative H-Ras and Raf-1 block LPA-induced uPA up-regulation, suggesting that the Ras-Raf pathway works downstream of G(i) to mediate this LPA-induced process. Surprisingly, dominant negative MEK1 or Erk2 displays only marginal inhibitory effect on LPA-induced uPA up-regulation, suggesting that a signaling pathway distinct from Raf-MEK1/2-Erk is the prominent pathway responsible for this process. In this report, we demonstrate that LPA activates NF-kappaB in a Ras-Raf-dependent manner and that blocking NF-kappaB activation with either non-phosphorylable IkappaB or dominant negative IkappaB kinase abolished LPA-induced uPA up-regulation and uPA promoter activation. Furthermore, introducing mutations to knock out the NF-kappaB binding site of the uPA promoter results in over 80% reduction in LPA-induced uPA promoter activation, whereas this activity is largely intact with the promoter containing mutations in the AP1 binding sites. Thus these results suggest that the G(i)-Ras-Raf-NF-kappaB signaling cascade is responsible for LPA-induced uPA up-regulation in ovarian cancer cells.
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Affiliation(s)
- Hongbin Li
- Department of Immunology and Molecular Biology, The Scripps Research Institute, 10550 N. Torrey Pines Rd., La Jolla, California 92037, USA
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27
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Ryoo K, Huh SH, Lee YH, Yoon KW, Cho SG, Choi EJ. Negative Regulation of MEKK1-induced Signaling by Glutathione S-Transferase Mu. J Biol Chem 2004; 279:43589-94. [PMID: 15299005 DOI: 10.1074/jbc.m404359200] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mitogen-activated protein kinase/extracellular signal-regulated kinase kinase kinase 1 (MEKK1) is an important component in the stress-activated protein kinase pathway. Glutathione S-transferase Mu 1-1 (GST M1-1) has now been shown to inhibit the stimulation of MEKK1 activity induced by cellular stresses such as UV and hydrogen peroxide. GST M1-1 inhibited MEKK1 activation in a manner independent of its glutathione-conjugating catalytic activity. In vitro binding and kinase assays revealed that GST M1-1 directly bound MEKK1 and inhibited its kinase activity. Co-immunoprecipitation analysis showed a physical association between endogenous GST M1-1 and endogenous MEKK1 in L929 cells. Overexpressed GST M1-1 interfered with the binding of MEKK1 to SEK1 in transfected HEK293 cells. Furthermore, GST M1-1 suppressed MEKK1-mediated apoptosis. Taken together, our results suggest that GST M1-1 functions as a negative regulator of MEKK1.
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Affiliation(s)
- Kanghyun Ryoo
- National Creative Research Initiative Center for Cell Death, School of Life Sciences and Biotechnology, Korea University, Seoul 136-701, South Korea
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28
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Xia Y, Kao WWY. The signaling pathways in tissue morphogenesis: a lesson from mice with eye-open at birth phenotype. Biochem Pharmacol 2004; 68:997-1001. [PMID: 15313393 DOI: 10.1016/j.bcp.2004.05.028] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2004] [Accepted: 05/05/2004] [Indexed: 02/06/2023]
Abstract
Tissue morphogenesis during development is regulated by growth factors and cytokines, and is characterized by constant remodeling of extracellular matrix in response to signaling molecules. MEK kinase 1 (MEKK1) is a mitogen-activated protein kinase (MAPK) kinase kinase originally identified as an upstream activator for several MAPK pathways. During mouse embryogenesis, MEKK1 controls cell shape changes and formation of actin stress fibers that are required for sealing epidermis in the embryos in a process known as eyelid closure. MEKK1-null mice display eye-open at birth (EOB), a phenotype found also in mice impaired in activin, a subgroup of the transforming growth factor beta (TGFbeta) family, or in epidermal growth factor receptor (EGFR) or its ligand TGFalpha, or in transcription factor c-Jun. Molecular analyses have revealed at least two signaling mechanisms in the control of eyelid closure. One is originated from the activins and is transduced through MEKK1, leading to transcription-independent actin stress fiber formation and transcription-dependent keratinocyte migration. Another is the TGFalpha/EGFR signal that is transduced through a MEKK1-independent pathway to the activation of the ERK MAPK, which also leads to keratinocyte migration. c-Jun might serve as a connection between the two pathways. As embryonic eyelid closure is a specific morphogenetic process that is easily detectable, genetic mutant mice with EOB will be ideal models to understand the signaling mechanisms in the control of epithelial cell migration and the morphogenetic process of epithelial sheet movement.
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Affiliation(s)
- Ying Xia
- Department of Environmental Health, Center for Environmental Genetics, University of Cincinnati Medical Center, OH 45267-0056, USA.
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29
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Bian D, Su S, Mahanivong C, Cheng RK, Han Q, Pan ZK, Sun P, Huang S. Lysophosphatidic Acid Stimulates Ovarian Cancer Cell Migration via a Ras-MEK Kinase 1 Pathway. Cancer Res 2004; 64:4209-17. [PMID: 15205333 DOI: 10.1158/0008-5472.can-04-0060] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Lysophosphatidic acid (LPA) is present at high concentrations in ascites and plasma of ovarian cancer patients. Studies conducted in experimental models demonstrate that LPA promotes ovarian cancer invasion/metastasis by up-regulating protease expression, elevating protease activity, and enhancing angiogenic factor expression. In this study, we investigated the effect of LPA on ovarian cancer migration, an essential component of cancer cell invasion. LPA stimulates both chemotaxis and chemokinesis of ovarian cancer cells and LPA-stimulated cell migration is G(I) dependent. Moreover, constitutively active H-Ras enhances ovarian cancer cell migration, whereas dominant negative H-Ras blocks LPA-stimulated cell migration, suggesting that Ras works downstream of G(i) to mediate LPA-stimulated cell migration. Interestingly, H-Ras mutants that specifically activate Raf-1, Ral-GDS, or phosphatidylinositol 3'-kinase are unable to significantly enhance ovarian cancer cell migration, suggesting that a Ras downstream effector distinct from Raf-1, Ral-GDS, and phosphatidylinositol 3'-kinase is responsible for LPA-stimulated cell migration. In this article, we demonstrate that LPA activates mitogen-activated protein kinase kinase 1 (MEKK1) in a G(i)-Ras-dependent manner and that MEKK1 activity is essential for LPA-stimulated ovarian cancer cell migration. Inhibitors that block MEKK1 downstream pathways, including MEK1/2, MKK4/7, and nuclear factor-kappa B pathways, do not significantly alter LPA-stimulated cell migration. Instead, LPA induces the redistribution of focal adhesion kinase to focal contact regions of the cytoplasm membrane, and this event is abolished by pertussis toxin, dominant negative H-Ras, or dominant negative MEKK1. Our studies thus suggest that the G(i)-Ras-MEKK1 signaling pathway mediates LPA-stimulated ovarian cancer cell migration by facilitating focal adhesion kinase redistribution to focal contacts.
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Affiliation(s)
- Dafang Bian
- Department of Immunology, The Scripps Research Institute, La Jolla, California 92037, USA
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30
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Takada Y, Khuri FR, Aggarwal BB. Protein Farnesyltransferase Inhibitor (SCH 66336) Abolishes NF-κB Activation Induced by Various Carcinogens and Inflammatory Stimuli Leading to Suppression of NF-κB-regulated Gene Expression and Up-regulation of Apoptosis. J Biol Chem 2004; 279:26287-99. [PMID: 15090542 DOI: 10.1074/jbc.m400963200] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Ras farnesyltransferase inhibitor (FTI) exhibit antiproliferative and antiangiogenic effects through a mechanism that is poorly understood. Because of the known role of Ras in the activation of transcription factor NF-kappaB and because NF-kappaB-regulated genes can control cell survival and angiogenesis, we postulated that FTI mediates its effects in part by modulating NF-kappaB activation. Therefore, in the present study we investigated the effect of FTI, SCH 66336, on NF-kappaB and NF-kappaB-regulated gene expression activated by a variety of inflammatory and carcinogenic agents. We demonstrate by DNA-binding assay that NF-kappaB activation induced by tumor necrosis factor (TNF), phorbol 12-myristate 13-acetate, cigarette smoke, okadaic acid, and H(2)O(2) was completely suppressed by SCH 66336; the suppression was not cell type-specific. This FTI suppressed the activation of IkappaBalpha kinase (IKK), thus abrogating the phosphorylation and degradation of IkappaBalpha. Additionally, TNF-activated Ras and SCH 66336 inhibited the activation. Also, overexpression of Ras (V12) enhanced TNF-induced NF-kappaB activation, and adenoviral dominant-negative Ras (N17) suppressed the activation, thus suggesting the critical role of Ras in TNF signaling. SCH 66336 also inhibited the NF-kappaB-dependent reporter gene expression activated by TNF, TNFR1, TRADD, TRAF2, NIK, and IKK but not that activated by the p65 subunit of NF-kappaB. The TNF-induced NF-kappaB-regulated gene products cyclin D1, COX-2, MMP-9, survivin, IAP1, IAP2, XIAP, Bcl-2, Bfl-1/A1, TRAF1, and FLIP were all down-regulated by SCH 66336, which potentiated apoptosis induced by TNF and doxorubicin. Overall, our results indicate that SCH 66336 inhibited activation of NF-kappaB and NF-kappaB-regulated gene expressions induced by carcinogens and inflammatory stimuli, which may provide a molecular basis for the ability of SCH 66336 to suppress proliferation and angiogenesis.
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Affiliation(s)
- Yasunari Takada
- Cytokine Research Laboratory, Department of Bioimmunotherapy, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA
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31
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Chaturvedi K, Sarkar DK. Involvement of protein kinase C-dependent mitogen-activated protein kinase p44/42 signaling pathway for cross-talk between estradiol and transforming growth factor-beta3 in increasing basic fibroblast growth factor in folliculostellate cells. Endocrinology 2004; 145:706-15. [PMID: 14605008 PMCID: PMC2895416 DOI: 10.1210/en.2003-1063] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
We have recently shown that TGF-beta3, in the presence of estradiol, increases the release of basic fibroblast growth factor (bFGF) from folliculostellate (FS) cells in the pituitary. We determined the interactive effects of TGF-beta3 and estradiol on bFGF production and release from FS cells, and the role of the MAPK pathway in TGF-beta3 and estradiol interaction. We found that TGF-beta3 and estradiol alone moderately increased cell content and release of bFGF from FS cells; but together, they markedly increased the peptide. Estradiol and TGF-beta3 alone moderately activated MAPK p44/42; together they produced marked activation of MAPK p44/42. Pretreatment of FS cells with an MAPK kinase 1/2 inhibitor or with protein kinase C inhibitors suppressed the activation of MAPK p44/42, bFGF release, and protein level increases, all of which were induced by TGF-beta3 and estradiol. Estradiol and TGF-beta3, either alone or in combination, increased the levels of active Ras. Furthermore, bFGF induction by TGF-beta3 and estradiol was blocked by overexpression of Ras N17, a dominant negative mutant of Ras p21. Estrogen receptor blocker ICI 182,780 failed to prevent estrogen's and TGF-beta3's effects on bFGF. These data suggest that an estradiol receptor-independent protein kinase C- activated Ras-dependent MAPK pathway is involved in the cross-talk between TGF-beta3 and estradiol to increase bFGF production and/or release from FS cells.
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Affiliation(s)
- Kirti Chaturvedi
- Endocrinology Program, Biomedical Division of the Center of Alcohol Studies and Department of Animal Sciences, Rutgers, The State University of New Jersey, 84 Lipman Drive, New Brunswick, NJ 08901, USA
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Gallagher ED, Gutowski S, Sternweis PC, Cobb MH. RhoA Binds to the Amino Terminus of MEKK1 and Regulates Its Kinase Activity. J Biol Chem 2004; 279:1872-7. [PMID: 14581471 DOI: 10.1074/jbc.m309525200] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
MEKK1 is a mitogen-activated protein kinase kinase kinase (MAP3K) that can regulate the c-Jun amino-terminal kinase (JNK) MAP kinase cascade. MEKK1 is comprised of a kinase domain and a long amino-terminal regulatory domain. This amino-terminal domain has a scaffold function in that it can assemble modules of the JNK and ERK MAP kinase cascades. Recently, we have demonstrated that MEKK1 binds to p115 Rho GTPase-activating protein, which has GTPase-activating protein activity toward RhoA. Thus, we tested whether Rho GTPases interact with the regulatory domain of MEKK1. RhoA, but not Rac or Cdc42, binds to a site in the aminoterminal one-third of MEKK1, which includes its PHD domain. The interaction is prevented by mutation of the essential cysteine in the MEKK1 PHD domain. Rho-GTP stimulates the kinase activity of full-length MEKK1 as much as 10-fold toward MEK4 but does not appear to be ubiquitinated by MEKK1 under conditions that result in modification of ERK2. In summary, we have characterized a novel point at which Rho GTPases impinge upon the regulation and function of MEKK1.
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Affiliation(s)
- Ewen D Gallagher
- Department of Pharmacology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-9041, USA
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33
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Zhou L, Tan A, Iasvovskaia S, Li J, Lin A, Hershenson MB. Ras and mitogen-activated protein kinase kinase kinase-1 coregulate activator protein-1- and nuclear factor-kappaB-mediated gene expression in airway epithelial cells. Am J Respir Cell Mol Biol 2003; 28:762-9. [PMID: 12600818 DOI: 10.1165/rcmb.2002-0261oc] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
In 16HBE14o- human bronchial epithelial cells, maximal tumor necrosis factor (TNF)-alpha-induced interleukin (IL)-8 expression depends on the activation of two distinct signaling pathways, one constituted in part by activator protein (AP)-1 and the other by nuclear factor (NF)-kappaB. We examined the upstream signaling intermediates responsible for IL-8 and granulocyte-macrophage colony-stimulating factor (GM-CSF) expression in this system, hypothesizing that p21 Ras and mitogen-activated protein kinase/extracellular signal-regulated kinase kinase kinase (MEKK)-1 function as common upstream activators of both the AP-1 and NF-kappaB pathways. TNF-alpha treatment induced both Ras and MEKK1 activation. Dominant-negative forms of Ras (N17Ras) and MEKK1 (MEKK1-KM) each inhibited TNF-alpha-induced transcription from IL-8 and GM-CSF promoters. Ras was required for maximal activation of extracellular signal-regulated kinase (ERK) and Jun amino terminal kinase (JNK) as well as AP-1 and NF-kappaB transcriptional activities, but not for activation of IkappaB kinase (IKK)-beta, an upstream activator of NF-kappaB. MEKK1 was required for maximal activation of ERK, JNK, and IKK, as well as for maximal AP-1 and NF-kappaB transcriptional activities. We conclude that Ras regulates TNF-alpha-induced chemokine expression by activating the AP-1 pathway and enhancing transcriptional function of NF-kappaB, whereas MEKK1 activates both the AP-1 and NF-kappaB pathways.
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Affiliation(s)
- Limei Zhou
- Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor, MI 48109-0212, USA
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34
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Yujiri T, Nawata R, Takahashi T, Sato Y, Tanizawa Y, Kitamura T, Oka Y. MEK kinase 1 interacts with focal adhesion kinase and regulates insulin receptor substrate-1 expression. J Biol Chem 2003; 278:3846-51. [PMID: 12458213 DOI: 10.1074/jbc.m206087200] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
MEK kinase 1 (MEKK1) has been shown to contribute to the regulation of cell migration, whereas focal adhesion kinase (FAK) is a major player involved in both cell migration and integrin signaling. Here we show that MEKK1 and FAK are co-immunoprecipitated from mouse fibroblasts. Moreover, the association between MEKK1 and FAK appears to be physiologically relevant, as it is enhanced by treatment with epidermal growth factor (EGF). Targeting FAK to the membrane also enhanced its association with MEKK1, indicating that MEKK1 is localized to a membrane-related subcellular domain, perhaps focal adhesions. Interestingly, the expression of insulin receptor substrate-1 (IRS-1) was diminished in MEKK1-deficient fibroblasts, which is similar to an earlier finding in FAK-deficient fibroblasts. Insulin-like growth factor 1 (IGF-1)-induced ERK activation was diminished in MEKK1-deficient cells, but phosphatidylinositol 3-kinase/Akt activation was not. Although integrin reportedly regulates the transcription of the IRS-1 gene via FAK-mediated JNK activation, no impairment of fibronectin-stimulated activation of FAK, ERK, or JNK was observed in MEKK1-deficient cells. Reconstitution of MEKK1 expression restored IRS-1 expression as well as IGF-1-induced ERK activation. Taken together, these findings indicate that MEKK1 interacts with FAK in focal adhesions and regulates IRS-1 expression.
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Affiliation(s)
- Toshiaki Yujiri
- Department of Bio-Signal Analysis, Yamaguchi University Graduate School of Medicine, Japan.
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35
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Ehrhardt A, Ehrhardt GRA, Guo X, Schrader JW. Ras and relatives--job sharing and networking keep an old family together. Exp Hematol 2002; 30:1089-106. [PMID: 12384139 DOI: 10.1016/s0301-472x(02)00904-9] [Citation(s) in RCA: 140] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Many members of the Ras superfamily of GTPases have been implicated in the regulation of hematopoietic cells, with roles in growth, survival, differentiation, cytokine production, chemotaxis, vesicle-trafficking, and phagocytosis. The well-known p21 Ras proteins H-Ras, N-Ras, K-Ras 4A, and K-Ras 4B are also frequently mutated in human cancer and leukemia. Besides the four p21 Ras proteins, the Ras subfamily of the Ras superfamily includes R-Ras, TC21 (R-Ras2), M-Ras (R-Ras3), Rap1A, Rap1B, Rap2A, Rap2B, RalA, and RalB. They exhibit remarkable overall amino acid identities, especially in the regions interacting with the guanine nucleotide exchange factors that catalyze their activation. In addition, there is considerable sharing of various downstream effectors through which they transmit signals and of GTPase activating proteins that downregulate their activity, resulting in overlap in their regulation and effector function. Relatively little is known about the physiological functions of individual Ras family members, although the presence of well-conserved orthologs in Caenorhabditis elegans suggests that their individual roles are both specific and vital. The structural and functional similarities have meant that commonly used research tools fail to discriminate between the different family members, and functions previously attributed to one family member may be shared with other members of the Ras family. Here we discuss similarities and differences in activation, effector usage, and functions of different members of the Ras subfamily. We also review the possibility that the differential localization of Ras proteins in different parts of the cell membrane may govern their responses to activation of cell surface receptors.
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Affiliation(s)
- Annette Ehrhardt
- The Biomedical Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
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36
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The Progression in the Mouse Skin Carcinogenesis Model Correlates With ERK1/2 Signaling. Mol Med 2002. [DOI: 10.1007/bf03402173] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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37
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Shapiro P. Ras-MAP kinase signaling pathways and control of cell proliferation: relevance to cancer therapy. Crit Rev Clin Lab Sci 2002; 39:285-330. [PMID: 12385501 DOI: 10.1080/10408360290795538] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The mitogen-activated protein (MAP) kinase pathways represent several families of signal transduction cascades that mediate information provided by extracellular stimuli. MAP kinase pathways regulate a wide range of physiological responses, including cell proliferation, apoptosis, cell differentiation, and tissue development. Constitutive activation of MAP kinase proteins in experimental models has been shown to cause cell transformation and is implicated in tumorigenesis. Of clinical importance, MAP kinase pathways are regulated by Ras G-proteins, which are found to be mutated and constitutively active in approximately 30% of all human cancers. Thus, a major goal in the treatment of cancer is the development of specific compounds that target Ras and critical downstream signaling proteins responsible for uncontrolled cell growth. A variety of biochemical, molecular, and structural approaches have been used to develop drug compounds that target signaling proteins important for MAP kinase pathway activation. These compounds have been useful tools for identifying the mechanisms of MAP kinase pathway signaling and hold promise for clinical use. This review will present an overview of the major proteins involved in Ras and MAP kinase signaling pathways and their function in regulating cell cycle events and proliferation. In addition, some of the relevant compounds that have been developed to inhibit the activities of these proteins and MAP kinase signaling are discussed.
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Affiliation(s)
- Paul Shapiro
- Department of Pharmaceutical Sciences, University of Maryland-School of Pharmacy, Baltimore 21201, USA
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38
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Christerson LB, Gallagher E, Vanderbilt CA, Whitehurst AW, Wells C, Kazempour R, Sternweis PC, Cobb MH. p115 Rho GTPase activating protein interacts with MEKK1. J Cell Physiol 2002; 192:200-8. [PMID: 12115726 DOI: 10.1002/jcp.10125] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Mammalian MAP/ERK kinase kinase 1 (MEKK1) was identified as a mammalian homolog of Ste11p of the yeast pheromone-induced mating pathway. Like Ste11p, MEKK1 is a MAP3 kinase linked to at least two MAP kinase cascades and regulatory events that require cytoskeletal reorganization. MEKK1 is activated by molecules that impact cytoskeletal function. MEKK1-/-cells are defective in cell migration, demonstrating that it is required for cell motility. MEKK1 has a 1,200 residue N-terminal regulatory domain that interacts with a dozen identified proteins. Using part of the MEKK1 N-terminus in a yeast two-hybrid screen, we discovered a novel interaction with p115 Rho GTPase-activating protein (GAP). The p115 Rho GAP binds to MEKK1 in vitro and in intact cells. The p115 Rho GAP has selectivity for RhoA over other Rho family members. Expression of p115 Rho GAP reduces MEKK1-induced signaling to AP-1. The reduced activation of AP-1 is dependent on the association of MEKK1 with p115 Rho GAP, because deletion of the Rho GAP SH3 domain, which abrogates their interaction, restores the stimulatory effect of MEKK1 on AP-1 activity. Here we have identified an MEKK1 binding partner that offers a connection between this protein kinase and the machinery regulating cytoskeletal reorganization.
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Affiliation(s)
- Lori B Christerson
- Department of Pharmacology, The University of Texas Southwestern Medical Center, Dallas, Texas 75390-9041, USA
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39
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Wu W, Jaspers I, Zhang W, Graves LM, Samet JM. Role of Ras in metal-induced EGF receptor signaling and NF-kappaB activation in human airway epithelial cells. Am J Physiol Lung Cell Mol Physiol 2002; 282:L1040-8. [PMID: 11943669 DOI: 10.1152/ajplung.00390.2001] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We showed previously that epithelial growth factor (EGF) receptor (EGFR) signaling is triggered by metallic compounds associated with ambient air particles. Specifically, we demonstrated that As, Zn, and V activated the EGFR tyrosine kinase and the downstream kinases MEK1/2 and ERK1/2. In this study, we examined the role of Ras in EGFR signaling and the nuclear factor-kappaB (NF-kappaB) activation pathway and the possible interaction between these two signaling pathways in a human airway epithelial cell line (BEAS-2B) exposed to As, V, or Zn ions. Each metal significantly increased Ras activity, and this effect was inhibited by the EGFR tyrosine kinase activity inhibitor PD-153035. Adenoviral-mediated overexpression of a dominant-negative mutant form of Ras(N17) significantly blocked MEK1/2 or ERK1/2 phosphorylation in As-, Zn-, or V-exposed BEAS-2B cells but caused little inhibition of V-, Zn- or EGF-induced EGFR tyrosine phosphorylation. This confirmed Ras as an important intermediate effector in EGFR signaling. Interestingly, V, but not As, Zn, or EGF, induced IkappaBalpha serine phosphorylation, IkappaBalpha breakdown, and NF-kappaB DNA binding. Moreover, PD-153035 and overexpression of Ras(N17) each significantly blocked V-induced IkappaBalpha breakdown and NF-kappaB activation, while inhibition of MEK activity with PD-98059 failed to do so. In summary, exposure to As, Zn, and V initiated EGFR signaling and Ras-dependent activation of MEK1/2 and ERK1/2, but only V induced Ras-dependent NF-kappaB nuclear translocation. EGFR signaling appears to cross talk with NF-kappaB signaling at the level of Ras, but additional signals appear necessary for NF-kappaB activation. Together, these data suggest that, in V-treated BEAS-2B cells, Ras-dependent signaling is essential, but not sufficient, for activation of NF-kappaB.
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Affiliation(s)
- Weidong Wu
- Center for Environmental Medicine and Lung Biology, University of North Carolina, Chapel Hill 27599, USA
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40
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Schlesinger TK, Bonvin C, Jarpe MB, Fanger GR, Cardinaux JR, Johnson GL, Widmann C. Apoptosis stimulated by the 91-kDa caspase cleavage MEKK1 fragment requires translocation to soluble cellular compartments. J Biol Chem 2002; 277:10283-91. [PMID: 11782455 DOI: 10.1074/jbc.m106885200] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
MEKK1, a 196-kDa mitogen-activated protein kinase (MAPK) kinase kinase, generates anti-apoptotic signaling as a full-length protein but induces apoptosis when cleaved by caspases. Here, we show that caspase-dependent cleavage of MEKK1 relocalizes the protease-generated 91-kDa kinase fragment from a particulate fraction to a soluble cytoplasmic fraction. Relocalization of MEKK1 catalytic activity is necessary for the pro-apoptotic function of MEKK1. The addition of a membrane-targeting signal to the 91-kDa fragment inhibits caspase activation and the induction of apoptosis but does not change the activation of JNK, ERK, NFkappaB, or p300. These results identify the caspase cleavage of MEKK1 as a dynamic regulatory mechanism that alters the subcellular distribution of MEKK1, changing its function to pro-apoptotic signaling, which does not depend on the currently described MEKK1 effectors.
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Affiliation(s)
- Thomas K Schlesinger
- Institute of Cellular Biology and Morphology, University of Lausanne, 1005 Lausanne, Switzerland
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41
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Chan ASL, Lai FPL, Lo RKH, Voyno-Yasenetskaya TA, Stanbridge EJ, Wong YH. Melatonin mt1 and MT2 receptors stimulate c-Jun N-terminal kinase via pertussis toxin-sensitive and -insensitive G proteins. Cell Signal 2002; 14:249-57. [PMID: 11812653 DOI: 10.1016/s0898-6568(01)00240-6] [Citation(s) in RCA: 106] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Melatonin is a pineal hormone involved in neuroendocrine processes in mammals. It has been shown that melatonin inhibits the enzymatic activities of adenylyl cyclases and the transcriptional activities of CREB. In this report, we demonstrate that 2-iodomelatonin (2IMT) treatment on COS-7 cells transfected with melatonin receptors (mt1 and MT2) induces c-Jun N-terminal kinase (JNK) activation, which is pertussis toxin (PTX)-sensitive, Ras/Rac-dependent and may involve Src-family protein tyrosine kinases. Moreover, PTX-insensitive Gs, Gz and G16 are capable of linking activated melatonin receptors to the stimulation of JNK. Agonist stimulation on PTX-pretreated COS-7 cells overexpressing mt1 receptor, Galpha(s) and adenylyl cyclase VI led to increased cAMP accumulation. Stimulation of endogenous mt1 receptors in MCF-7 cells was associated with the activation of both JNK and extracellular signal-regulated kinase (ERK). This report demonstrates the stimulatory effect of melatonin receptors on JNK, and provides experimental evidence for a functional coupling between the G(i)-coupled melatonin receptor and Gs, in terms of adenylyl cyclase activation.
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MESH Headings
- Adenylate Cyclase Toxin
- Animals
- COS Cells
- Chlorocebus aethiops
- GTP-Binding Protein alpha Subunits
- GTP-Binding Protein alpha Subunits, Gi-Go/metabolism
- GTP-Binding Protein alpha Subunits, Gq-G11
- GTP-Binding Protein alpha Subunits, Gs/metabolism
- GTP-Binding Proteins/metabolism
- Heterotrimeric GTP-Binding Proteins/metabolism
- Humans
- JNK Mitogen-Activated Protein Kinases
- MAP Kinase Signaling System/physiology
- Melatonin/analogs & derivatives
- Melatonin/metabolism
- Melatonin/pharmacology
- Mitogen-Activated Protein Kinase 1/metabolism
- Mitogen-Activated Protein Kinase 3
- Mitogen-Activated Protein Kinase 8
- Mitogen-Activated Protein Kinase 9
- Mitogen-Activated Protein Kinases/metabolism
- Molecular Weight
- Pertussis Toxin
- Proto-Oncogene Proteins p21(ras)/metabolism
- Receptors, Cell Surface/genetics
- Receptors, Cell Surface/metabolism
- Receptors, Cytoplasmic and Nuclear/genetics
- Receptors, Cytoplasmic and Nuclear/metabolism
- Receptors, Melatonin
- Tumor Cells, Cultured
- Virulence Factors, Bordetella/pharmacology
- rac1 GTP-Binding Protein/metabolism
- src-Family Kinases/metabolism
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Affiliation(s)
- Anthony S L Chan
- Department of Biochemistry the Biotechnology Research Institute, and the Molecular Neuroscience Center, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
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42
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Chadee DN, Yuasa T, Kyriakis JM. Direct activation of mitogen-activated protein kinase kinase kinase MEKK1 by the Ste20p homologue GCK and the adapter protein TRAF2. Mol Cell Biol 2002; 22:737-49. [PMID: 11784851 PMCID: PMC133545 DOI: 10.1128/mcb.22.3.737-749.2002] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2001] [Revised: 08/07/2001] [Accepted: 11/05/2001] [Indexed: 11/20/2022] Open
Abstract
Mitogen-activated protein kinase (MAPK) pathways coordinate critical cellular responses to mitogens, stresses, and developmental cues. The coupling of MAPK kinase kinase (MAP3K) --> MAPK kinase (MEK) --> MAPK core pathways to cell surface receptors remains poorly understood. Recombinant forms of MAP3K MEK kinase 1 (MEKK1) interact in vivo and in vitro with the STE20 protein homologue germinal center kinase (GCK), and both GCK and MEKK1 associate in vivo with the adapter protein tumor necrosis factor (TNF) receptor-associated factor 2 (TRAF2). These interactions may couple TNF receptors to the SAPK/JNK family of MAPKs; however, a molecular mechanism by which these proteins might collaborate to recruit the SAPKs/JNKs has remained elusive. Here we show that endogenous GCK and MEKK1 associate in vivo. In addition, we have developed an in vitro assay system with which we demonstrate that purified, active GCK and TRAF2 activate MEKK1. The RING domain of TRAF2 is necessary for optimal in vitro activation of MEKK1, but the kinase domain of GCK is not. Autophosphorylation within the MEKK1 kinase domain activation loop is required for activation. Forced oligomerization also activates MEKK1, and GCK elicits enhanced oligomerization of coexpressed MEKK1 in vivo. These results represent the first activation of MEKK1 in vitro using purified proteins and suggest a mechanism for MEKK1 activation involving induced oligomerization and consequent autophosphorylation mediated by upstream proteins.
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Affiliation(s)
- Deborah N Chadee
- Diabetes Research Laboratory, Medical Services, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129, USA
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43
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Abstract
MEK kinases (MEKKs) comprise a family of related serine-threonine protein kinases that regulate mitogen-activated protein kinase (MAPK) signalling pathways leading to c-Jun NH2-terminal kinase (JNK) and p38 activation, induced by cellular stress (e.g., UV and gamma irradiation, osmotic stress, heat shock, protein synthesis inhibitors), inflammatory cytokines (e.g., tumour necrosis factor alpha, TNFalpha, and interleukin-1, IL1) and G protein-coupled receptor agonists (e.g., thrombin). These stress-activated kinases have been implicated in apoptosis, oncogenic transformation, and inflammatory responses in various cell types. At present, the signalling events involving MEKKs are not well understood. This review summarises our current knowledge concerning the regulation and function of MEKK family members, with particular emphasis on those factors capable of directly interacting with distinct MEKK isoforms.
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Affiliation(s)
- C Hagemann
- Department of Cell Physiology and Pharmacology, University of Leicester, Medical Sciences Building, University Road, LE1 9HN, Leicester, UK
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44
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Lengyel E, Ried S, Heiss MM, Jäger C, Schmitt M, Allgayer H. Ras regulation of urokinase-type plasminogen activator. Methods Enzymol 2001; 333:105-16. [PMID: 11400328 DOI: 10.1016/s0076-6879(01)33049-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Affiliation(s)
- E Lengyel
- Department of Obstetrics, Gynecology, and Reproductive Sciences and Cancer Research Institute, University of California, San Francisco, California 94143-0875, USA
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45
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Lenz G, Gonçalves D, Luo Z, Avruch J, Rodnight R, Neary JT. Extracellular ATP stimulates an inhibitory pathway towards growth factor-induced cRaf-1 and MEKK activation in astrocyte cultures. J Neurochem 2001; 77:1001-9. [PMID: 11359865 DOI: 10.1046/j.1471-4159.2001.00299.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
ATP, acting via P2Y, G protein-coupled receptors (GPCRs), is a mitogenic signal and also synergistically enhances fibroblast growth factor-2 (FGF-2)-induced proliferation in astrocytes. Here, we have examined the effects of ATP and FGF-2 cotreatment on the main components of the extracellular-signal regulated protein kinase (ERK) cascade, cRaf-1, MAPK/ERK kinase (MEK) and ERK, key regulators of cellular proliferation. Surprisingly, ATP inhibited activation of cRaf-1 by FGF-2 in primary cultures of rat cortical astrocytes. The inhibitory effect did not diminish MEK and ERK activation; indeed, cotreatment resulted in a greater initial activation of ERK. ATP inhibition of cRaf-1 activation was not mediated by an increase in cyclic AMP levels or by protein kinase C activation. ATP also inhibited the activation of cRaf-1 by other growth factors, epidermal growth factor and platelet-derived growth factor, as well as other MEK1 activators stimulated by FGF-2, MEK kinase 1 (MEKK1) and MEKK2. Serotonin, an agonist of another GPCR coupled to ERK, did not inhibit FGF-2-induced cRaf-1 activation, thereby indicating specificity in the ATP-induced inhibitory cross-talk. These findings suggest that ATP stimulates an inhibitory activity that lays upstream of MEK activators and inhibits growth factor-induced activation of cRaf-1 and MEKKS: Such a mechanism might serve to integrate the actions of receptor tyrosine kinases and P2Y-GPCRS:
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Affiliation(s)
- G Lenz
- Departments of Biofísica and Bioquímica, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
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46
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Abstract
Stat3 is a latent transcription factor activated by various cytokines and growth factors. Phosphorylation on Tyr-705 is a prerequisite for dimer formation, nuclear translocation, binding to its cognate DNA sequences, and regulation of the target gene transcription. Ser-727 phosphorylation of Stat3 plays an additional role in the regulation of transcription. MEK kinase 1 (MEKK1) is a mitogen-activated protein kinase (MAPK) kinase kinase (MAPKKK) that activates the c-Jun NH(2)-terminal kinase signaling pathway. Here we report that MEKK1 is involved in the regulation of Stat3 activation by growth factors. Kinase-inactive MEKK1 inhibits Stat3 phosphorylation on tyrosine and serine, and its transcriptional activity stimulated by epidermal growth factor and platelet-derived growth factor in different cell types. In contrast, active MEKK1 induces Stat3 tyrosine and serine phosphorylation leading to a functionally active Stat3 capable of binding DNA and enhancing transcription. Ser-727 is phosphorylated by MEKK1 in vitro, whereas Tyr-705 phosphorylation induced by MEKK1 involves Src and Janus kinases in vivo. These data demonstrate for the first time a novel role of MEKK1 to modulate tyrosine kinases that results in the activation of specific members of STAT family.
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Affiliation(s)
- C P Lim
- Institute of Molecular and Cell Biology, Singapore 117609, Singapore
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47
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Kyriakis JM, Avruch J. Mammalian mitogen-activated protein kinase signal transduction pathways activated by stress and inflammation. Physiol Rev 2001; 81:807-69. [PMID: 11274345 DOI: 10.1152/physrev.2001.81.2.807] [Citation(s) in RCA: 2515] [Impact Index Per Article: 109.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The molecular details of mammalian stress-activated signal transduction pathways have only begun to be dissected. This, despite the fact that the impact of these pathways on the pathology of chronic inflammation, heart disease, stroke, the debilitating effects of diabetes mellitus, and the side effects of cancer therapy, not to mention embryonic development, innate and acquired immunity, is profound. Cardiovascular disease and diabetes alone represent the most significant health care problems in the developed world. Thus it is not surprising that understanding these pathways has attracted wide interest, and in the past 10 years, dramatic progress has been made. Accordingly, it is now becoming possible to envisage the transition of these findings to the development of novel treatment strategies. This review focuses on the biochemical components and regulation of mammalian stress-regulated mitogen-activated protein kinase (MAPK) pathways. The nuclear factor-kappa B pathway, a second stress signaling paradigm, has been the subject of several excellent recent reviews (258, 260).
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Affiliation(s)
- J M Kyriakis
- Diabetes Research Laboratory, Medical Services, Massachusetts General Hospital, Boston, Massachusetts 02129, USA.
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48
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López-Maderuelo MD, Fernández-Renart M, Moratilla C, Renart J. Opposite effects of the Hsp90 inhibitor Geldanamycin: induction of apoptosis in PC12, and differentiation in N2A cells. FEBS Lett 2001; 490:23-7. [PMID: 11172804 DOI: 10.1016/s0014-5793(01)02130-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The inhibitor of the Hsp90 chaperone Geldanamycin has been reported to have several cellular effects, such as inhibition of v-src activity or destabilization of Raf-1 among others. We show now that Geldanamycin treatment induces different phenotypes in different cell lines. In PC12 cells, it triggers apoptosis, whereas in the murine neuroblastoma N2A, it induces differentiation with neurite outgrowth. Geldanamycin effects cannot be mimicked by inhibition of the c-src protein tyrosine kinases, and nerve growth factor does not protect PC12 cells from apoptosis. Mitogen-activated protein kinase activities ERK and JNK are activated differently according to cell type: in PC12 cells JNK is activated, and its inhibition abolishes apoptosis, but not ERK; in N2A cells, both ERK and JNK are activated, but with peak activities at different times.
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Affiliation(s)
- M D López-Maderuelo
- Instituto de Investigaciones Biomédicas Alberto Sols CSIC-UAM, Arturo Duperier 4, 28029 Madrid, Spain
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49
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Wang D, Richmond A. Nuclear factor-kappa B activation by the CXC chemokine melanoma growth-stimulatory activity/growth-regulated protein involves the MEKK1/p38 mitogen-activated protein kinase pathway. J Biol Chem 2001; 276:3650-9. [PMID: 11062239 PMCID: PMC2676351 DOI: 10.1074/jbc.m006115200] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Melanoma growth stimulatory activity/growth-regulated protein (MGSA/GRO), a CXC chemokine, plays an important role in inflammation, wound healing, growth regulation, angiogenesis, and tumorigenesis. Constitutive expression of MGSA/GROalpha in melanoma tumors is associated with constitutive nuclear factor (NF)-kappaB activity. We show here that either exogenous addition or continuous expression of MGSA/GROalpha in immortalized melanocytes enhances NF-kappaB activation, as well as mitogen-activated protein (MAP) kinase kinase kinase (MEKK) 1, MAP kinase kinase (MEK) 3/6, and p38 MAP kinase activation. Expression of dominant negative M-Ras (S27N), dominant negative MEKK1 (K432M), or specific chemical inhibitors for p38 MAP kinase (SB202190 and SB203580) block MGSA/GROalpha-induced NF-kappaB transactivation, demonstrating that Ras, MEKK1, and p38 are involved in the signal pathways of MGSA/GROalpha activation of NF-kappaB. Expression of dominant active Ras or dominant active MEKK1 alone can also stimulate NF-kappaB activation. The expression of dominant negative MEKK1 inhibits the Ras-induced NF-kappaB activation, suggesting that MEKK1 is a downstream target of Ras. Moreover, MGSA/GROalpha induction of NF-kappaB is independent of the MEK1/ERK cascade, because MGSA/GROalpha failed to increase ERK and ELK activation, and specific chemical inhibitors for MEK1 (PD98059) had no effect on MGSA/GROalpha-enhanced NF-kappaB activation. These data demonstrate that NF-kappaB activation is required for MGSA/GROalpha-induced melanocyte transformation through a Ras/MEKK1/p38 cascade in melanocytes.
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Affiliation(s)
- Dingzhi Wang
- Department of Cell Biology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232
| | - Ann Richmond
- Department of Veterans Affairs, Vanderbilt University School of Medicine, Nashville, Tennessee 37232
- Department of Cell Biology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232
- To whom correspondence should be addressed: Dept. of Cell Biology, Vanderbilt University School of Medicine, Nashville, TN 37232. Tel.: 615-343-7777; Fax: 615-343-4539; E-mail:
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50
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Pal S, Datta K, Khosravi-Far R, Mukhopadhyay D. Role of protein kinase Czeta in Ras-mediated transcriptional activation of vascular permeability factor/vascular endothelial growth factor expression. J Biol Chem 2001; 276:2395-403. [PMID: 11060301 DOI: 10.1074/jbc.m007818200] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Vascular permeability factor/vascular endothelial growth factor (VPF/VEGF), a multifunctional cytokine, is regulated by different factors including degree of cell differentiation, hypoxia, and certain oncogenes namely, ras and src. The up-regulation of VPF/VEGF expression by Ras has been found to be through both transcription and mRNA stability. The present study investigates a novel pathway whereby Ras promotes the transcription of VPF/VEGF by activating protein kinase Czeta (PKCzeta). The Ras-mediated overexpression of VPF/VEGF was also found to be inhibited by using the antisense or the dominant-negative mutant of PKCzeta. In co-transfection assays, by overexpressing oncogenic Ha-Ras (12 V) and PKCzeta, there was an additive effect up to 4-fold in activation of Sp1-mediated VPF/VEGF transcription. It has been shown through electrophoretic mobility shift assay that Ras promoted the PKCzeta-induced binding of Sp1 to the VPF/VEGF promoter. In the presence of PDK-1, a major activating kinase for PKC, the Ras-mediated activation of VPF/VEGF promoter through PKCzeta was further increased, suggesting that PKCzeta can serve as an effector for both Ras and PDK-1. In other experiments, with the use of a dominant-negative mutant of phosphatidylinositol 3-kinase, the activation of VPF/VEGF promoter through Ras, PDK-1, and PKCzeta was completely repressed, indicating phosphatidylinositol 3-kinase as an important component of this pathway. Taken together, these data elucidate the signaling mechanism of Ras-mediated VPF/VEGF transcriptional activation through PKCzeta and also provide insight into PKCzeta and Sp1-dependent transcriptional regulation of VPF/VEGF.
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Affiliation(s)
- S Pal
- Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02215, USA
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