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Wu QN, Liao YF, Lu YX, Wang Y, Lu JH, Zeng ZL, Huang QT, Sheng H, Yun JP, Xie D, Ju HQ, Xu RH. Pharmacological inhibition of DUSP6 suppresses gastric cancer growth and metastasis and overcomes cisplatin resistance. Cancer Lett 2017; 412:243-255. [PMID: 29050982 DOI: 10.1016/j.canlet.2017.10.007] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 09/29/2017] [Accepted: 10/09/2017] [Indexed: 01/08/2023]
Abstract
Gastric cancer (GC) is the second cause of cancer-related death. Cisplatin (CDDP) is widely used as the standard GC treatment, but relapse and metastasis are common because of intrinsic or acquired drug resistance. The mitogen-activated protein kinase phosphatases (MAPK)-extracellular signal regulated kinases (ERK) pathway contributes to GC progression and drug resistance, but targeting the MAPK-ERK pathway is challenging in GC therapy. Here, we demonstrated that dual-specificity phosphatases 6 (DUSP6) was overexpressed in GC and predicted poor overall survival and progression-free survival. Knockdown DUSP6 inhibited GC proliferation, migration, invasion and induced apoptosis. (E/Z)-BCI hydrochloride (BCI), a DUSP6 small molecule inhibitor, increased the activity of ERK but interestingly decreased the expression of ERK response genes in BGC823, SGC7901 and CDDP-resistant SGC7901/DDP cells. BCI also caused cell death through the DNA damage response (DDR) pathway. Moreover, BCI inhibited cell proliferation, migration and invasion in a receptor-independent manner and enhanced CDDP cytotoxicity at pharmacological concentrations in the GC cells. In vivo experiments further showed that BCI enhances the antitumor effects of CDDP in cell-based xenografts and PDX models. In summary, our findings indicated that disruption of DUSP6 by BCI enhanced CDDP-induced cell death and apoptosis in GC may partly through ERK and DDR pathways. Thus, this study suggests that DUSP6 is a potential prognostic biomarker and a promising target for GC therapy.
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Affiliation(s)
- Qi-Nian Wu
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China
| | - Yi-Fu Liao
- Guangdong General Hospital, Guangdong Neuroscience Institute, Guangdong Academy of Medical Sciences, Department of Neurology, Guangzhou, 510080, China
| | - Yun-Xin Lu
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China
| | - Yun Wang
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China
| | - Jia-Huan Lu
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China
| | - Zhao-Lei Zeng
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China
| | - Qi-Tao Huang
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China
| | - Hui Sheng
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China
| | - Jing-Ping Yun
- Sun Yat-sen University Cancer Center, Department of Pathology, Guangzhou, 510060, China
| | - Dan Xie
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China
| | - Huai-Qiang Ju
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China.
| | - Rui-Hua Xu
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China.
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Meeusen B, Janssens V. Tumor suppressive protein phosphatases in human cancer: Emerging targets for therapeutic intervention and tumor stratification. Int J Biochem Cell Biol 2017; 96:98-134. [PMID: 29031806 DOI: 10.1016/j.biocel.2017.10.002] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Revised: 10/04/2017] [Accepted: 10/05/2017] [Indexed: 02/06/2023]
Abstract
Aberrant protein phosphorylation is one of the hallmarks of cancer cells, and in many cases a prerequisite to sustain tumor development and progression. Like protein kinases, protein phosphatases are key regulators of cell signaling. However, their contribution to aberrant signaling in cancer cells is overall less well appreciated, and therefore, their clinical potential remains largely unexploited. In this review, we provide an overview of tumor suppressive protein phosphatases in human cancer. Along their mechanisms of inactivation in defined cancer contexts, we give an overview of their functional roles in diverse signaling pathways that contribute to their tumor suppressive abilities. Finally, we discuss their emerging roles as predictive or prognostic markers, their potential as synthetic lethality targets, and the current feasibility of their reactivation with pharmacologic compounds as promising new cancer therapies. We conclude that their inclusion in clinical practice has obvious potential to significantly improve therapeutic outcome in various ways, and should now definitely be pushed forward.
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Affiliation(s)
- Bob Meeusen
- Laboratory of Protein Phosphorylation & Proteomics, Dept. of Cellular & Molecular Medicine, Faculty of Medicine, KU Leuven & Leuven Cancer Institute (LKI), KU Leuven, Belgium
| | - Veerle Janssens
- Laboratory of Protein Phosphorylation & Proteomics, Dept. of Cellular & Molecular Medicine, Faculty of Medicine, KU Leuven & Leuven Cancer Institute (LKI), KU Leuven, Belgium.
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The regulation of oncogenic Ras/ERK signalling by dual-specificity mitogen activated protein kinase phosphatases (MKPs). Semin Cell Dev Biol 2016; 50:125-32. [PMID: 26791049 PMCID: PMC5056954 DOI: 10.1016/j.semcdb.2016.01.009] [Citation(s) in RCA: 153] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 01/06/2016] [Indexed: 11/20/2022]
Abstract
Dual-specificity MAP kinase (MAPK) phosphatases (MKPs or DUSPs) are well-established negative regulators of MAPK signalling in mammalian cells and tissues. By virtue of their differential subcellular localisation and ability to specifically recognise, dephosphorylate and inactivate different MAPK isoforms, they are key spatiotemporal regulators of pathway activity. Furthermore, as they are transcriptionally regulated as downstream targets of MAPK signalling they can either act as classical negative feedback regulators or mediate cross talk between distinct MAPK pathways. Because MAPKs and particularly Ras/ERK signalling are implicated in cancer initiation and development, the observation that MKPs are abnormally regulated in human tumours has been interpreted as evidence that these enzymes can either suppress or promote carcinogenesis. However, definitive evidence of such roles has been lacking. Here we review recent work based on the use of mouse models, biochemical studies and clinical data that demonstrate key roles for MKPs in modulating the oncogenic potential of Ras/ERK signalling and also indicate that these enzymes may play a role in the response of tumours to certain anticancer drugs. Overall, this work reinforces the importance of negative regulatory mechanisms in modulating the activity of oncogenic MAPK signalling and indicates that MKPs may provide novel targets for therapeutic intervention in cancer.
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Prognostic value of dual-specificity phosphatase 6 expression in non-small cell lung cancer. Tumour Biol 2014; 36:1199-206. [PMID: 25344212 DOI: 10.1007/s13277-014-2729-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Accepted: 10/09/2014] [Indexed: 10/24/2022] Open
Abstract
Dual-specificity phosphatase 6 (DUSP6/MKP-3) is a mitogen-activated protein kinase phosphatase that regulates extracellular signal-regulated kinases (ERKs) activity via feedback mechanisms, with an increasingly recognized role in tumour biology. The aim of this study was to explore the role of DUSP6 expression in the prognosis of human non-small cell lung cancer (NSCLC). DUSP6 expression levels were evaluated by real-time quantitative reverse transcription polymerase chain reaction (PCR) in 60 NSCLC samples from patients who underwent pulmonary resection at 12 de Octubre University Hospital. We performed a statistical analysis to investigate the correlation of DUSP6 expression and the clinical outcomes. We found that 66.7% of the tumour samples show the downregulation of DUSP6 at the messenger RNA (mRNA) levels compared to benign epithelial lung tissues and 55% of them show at least twofold downregulation of DUSP6 gene expression. Patients were classified into three groups according to their DUSP6 expression levels and those with very low levels (at least twofold downregulation) had the worst outcomes. Using the value of twice below the mean value in benign epithelial lung tissue as a cutoff, the overall survival of patients with very low DUSP6 levels was significantly lower than that in the rest of patients (31.9 ± 18.8 months vs. not reached, P = 0.049). This was most pronounced in adenocarcinoma histology and high-stage tumour samples. Our results suggest that DUSP6 gene expression in tumour samples may be a prognostic marker in NSCLC.
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3-Acetyl-bis(2-chloro-4-nitrophenyl)triazene is a potent antitumor agent that induces oxidative stress and independently activates the stress-activated protein kinase/c-Jun NH2-terminal kinase pathway. Anticancer Drugs 2014; 25:289-95. [PMID: 24322543 DOI: 10.1097/cad.0000000000000060] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Previously, we described the synthesis and biological activity of a new class of anticancer molecules that preferentially target malignant cells and may serve as potential antitumor agents. Among several synthesized agents, we selected 3-acetyl-1,3-bis(2-chloro-4-nitrophenyl)-1-triazene (8b) as a representative of the group of 4-nitro-substituted 1,3-diaryltriazenes. The aim of this study was to further investigate the mechanism of cell response to the 8b compound. The HeLa human cervical carcinoma cell line was used as an experimental model to further investigate the mechanism of cell response to the 8b compound. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric assay was used to address cell survival, and western blot (immunoblotting) was used for the expression of relevant proteins after 8b drug exposure. The pretreatment of HeLa cells with salubrinal, a specific inhibitor of endoplasmic reticulum (ER) stress, confirmed the importance of ER stress in apoptosis induced by 8b. We also demonstrate that 8b triggers the activation of stress-activated protein kinase/c-Jun NH2-terminal kinase (SAPK/JNK) in a time-dependent and dose-dependent manner. Moreover, the inhibition of SAPK/JNK activity by JNK II before 8b treatment increased the survival rate of HeLa cells relative to survival in the presence of 8b alone, indicating the importance of this kinase in cell death. The simultaneous inhibition of ER stress induction and SAPK/JNK activation increased the survival of HeLa cells upon 8b treatment more than inhibition of both pathways independently, suggesting the separate triggering of both signaling pathways. Our data indicate that cytotoxic activity of the novel compound 8b is based on its ability to induce ER stress and SAPK/JNK signaling pathways independently, driving cells to cell death.
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Messina S, Frati L, Leonetti C, Zuchegna C, Di Zazzo E, Calogero A, Porcellini A. Dual-specificity phosphatase DUSP6 has tumor-promoting properties in human glioblastomas. Oncogene 2011; 30:3813-20. [DOI: 10.1038/onc.2011.99] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Halterman MW. An improved method for the study of apoptosis-related genes using the tet-on system. ACTA ACUST UNITED AC 2011; 16:332-7. [PMID: 21335597 DOI: 10.1177/1087057110397355] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Inducible gene expression systems are particularly useful for the functional characterization of genes with putative toxic properties. In the course of studying the role of hypoxia-regulated gene expression on cell survival using the tetracycline-inducible (tet-on) system, the author noted that exposure to the inducing ligand doxycycline (dox) inhibited caspase-3 cleavage in control samples. To limit this confounding off-target effect, he devised an in vitro pulse dose, delayed-injury protocol testing both dox and a novel tetracycline analog 9-t-butyl doxycycline (9-TB). Although 9-TB induced higher transgene levels compared to matched concentrations of dox, continuous exposure to both drugs inhibited caspase-3 cleavage in hypoxic samples. Conversely, a 6-h pulse dose of 9-TB followed by a 40-h washout period prior to hypoxic challenge activated robust transgene expression and lessened the inhibitory effects on caspase-3 processing. It is anticipated that these protocol modifications will improve the performance of tet-regulated genetic screens, particularly in situations where cell death is used as a primary end point.
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Affiliation(s)
- Marc W Halterman
- Department of Neurology, Center for Neural Development and Disease, University of Rochester Medical Center, Rochester, NY 14642, USA.
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9
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Wattenberg EV. Modulation of protein kinase signaling cascades by palytoxin. Toxicon 2010; 57:440-8. [PMID: 21070801 DOI: 10.1016/j.toxicon.2010.11.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2010] [Revised: 10/26/2010] [Accepted: 11/02/2010] [Indexed: 10/18/2022]
Abstract
Although known for its acutely toxic action, palytoxin has also been identified as a type of carcinogenic agent called a tumor promoter. In general tumor promoters do not damage DNA, but instead contribute to carcinogenesis by disrupting the regulation of cellular signaling. The identification of palytoxin as a tumor promoter, together with the recognition that the Na(+), K(+)-ATPase is its receptor, led to research on how palytoxin triggers the modulation of signal transduction pathways. This review focuses on mitogen activated protein (MAP) kinases as mediators of palytoxin-stimulated signaling. MAP kinases are a family of serine/threonine kinases that relay a variety of signals to the cellular machinery that regulates cell fate and function. The studies discussed in this review investigated how palytoxin stimulates MAP kinase activity and, in turn, how MAP kinases mediate the response of cells to palytoxin.
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Affiliation(s)
- Elizabeth V Wattenberg
- Division of Environmental Health Sciences, School of Public Health, University of Minnesota, Mayo Mail Code #807, 420 Delaware Street SE, Minneapolis, MN 55455, USA.
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Zhang Z, Kobayashi S, Borczuk AC, Leidner RS, Laframboise T, Levine AD, Halmos B. Dual specificity phosphatase 6 (DUSP6) is an ETS-regulated negative feedback mediator of oncogenic ERK signaling in lung cancer cells. Carcinogenesis 2010; 31:577-86. [PMID: 20097731 DOI: 10.1093/carcin/bgq020] [Citation(s) in RCA: 134] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Mitogen-activated protein kinase (MAPK) pathway signaling plays an important role in the majority of non-small-cell lung cancers (NSCLCs). In a prior microarray analysis of epidermal growth factor receptor (EGFR) inhibition in NSCLC cell lines, we noted that several dual specificity phosphatases (DUSPs) were among the most highly and immediately regulated genes. DUSPs act as natural terminators of MAPK signal transduction and therefore, we hypothesized a tumor suppressive role via feedback mechanisms. In the current study, we focus on the assessment of DUSP6, a cytoplasmic DUSP with high specificity for extracellular signal-regulated kinase (ERK). We demonstrate that DUSP6 expression tracks in tandem with ERK inhibition and that regulation of DUSP6 is mediated at the promoter level by ETS1, a well-known nuclear target of activated ERK. Small interfering RNA knockdown in DUSP6-high H441 lung cancer cells significantly increased ERK activation and cellular proliferation, whereas plasmid-driven overexpression in DUSP6-low H1975 lung cancer cells significantly reduced ERK activation and cellular proliferation and promoted apoptosis. Also, DUSP6 overexpression synergized with EGFR inhibitor treatment in EGFR-mutant HCC827 cells. Our results indicate that DUSP6 expression is regulated by ERK signaling and that DUSP6 exerts antitumor effects via negative feedback regulation, pointing to an important feedback loop in NSCLC. Further studies assessing the tumor suppressive role of DUSP6 and strategies aimed at modulation of its activity are warranted.
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Affiliation(s)
- Zhenfeng Zhang
- Department of Pathology, Case Western Reserve University School of Medicine, University Hospitals-Case Medical Center and Ireland Cancer Center, Case Comprehensive Cancer Center, Cleveland, OH 44106, USA
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Essafi-Benkhadir K, Pouysségur J, Pagès G. Implication of the ERK pathway on the post-transcriptional regulation of VEGF mRNA stability. Methods Mol Biol 2010; 661:451-69. [PMID: 20812001 DOI: 10.1007/978-1-60761-795-2_28] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Vascular Endothelial Growth Factor-A (VEGF-A) is one of the most important regulators of physiological and pathological angiogenesis. Constitutive activation of the ERK pathway and over-expression of VEGF-A are common denominators of tumours of different origins. Understanding VEGF-A regulation is of primary importance to better comprehend pathological angiogenesis. VEGF-A expression is regulated at all steps of its synthesis including transcription, mRNA stability, an under estimated way of VEGF regulation and translation. In this chapter, we present the link between VEGF mRNA stability through AU-rich sequences present in its 3'-untranslated region (3'-UTR) and the ERK pathway. We present several methods that have been used to demonstrate that ERKs increase VEGF mRNA half-life. This mRNA-stabilising effect is partly due to reduction of the mRNA destabilising effects of Tristetraprolin (TTP), an AU-Rich binding protein which binds to VEGF-A mRNA 3'-UTR.
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Grépin R, Pagès G. Le Vascular Endothelial Growth Factor (VEGF) : un modèle de régulation d'expression génique et un marqueur d'agressivité tumorale. Une cible thérapeutique évidente ? ACTA ACUST UNITED AC 2009; 203:181-92. [DOI: 10.1051/jbio/2009022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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13
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Essafi-Benkhadir K, Grosso S, Puissant A, Robert G, Essafi M, Deckert M, Chamorey E, Dassonville O, Milano G, Auberger P, Pagès G. Dual role of Sp3 transcription factor as an inducer of apoptosis and a marker of tumour aggressiveness. PLoS One 2009; 4:e4478. [PMID: 19212434 PMCID: PMC2636865 DOI: 10.1371/journal.pone.0004478] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2008] [Accepted: 01/08/2009] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND The ambiguous role of transcription factor Sp3 for tumour progression is still debated since it was described as a transcriptional repressor or activator. Here we tried to decipher the molecular mechanisms implicated in Sp3 accumulation observed in aggressive tumours. METHODOLOGY We generated normal and tumour cell lines conditionally expressing Sp3. Cell growth was analyzed in vitro and after inoculation in nude mice. Apoptosis was assessed by pan- caspase activity assays, by counting fragmented nuclei and by determination of caspase 9 cleavage. Gene expression was determined by quantitative PCR. Cleavage by different caspases was performed after in vitro translation of the Sp3 cDNA in the presence of [S(35)] labelled methionine. Different tumour cell lines and head and neck tumour samples were tested for the presence of Sp3 by western blots. Correlation between Sp3 expression and overall survival has been statistically determined. PRINCIPAL FINDINGS Conditional over-expression of Sp3 induces apoptosis and modifies expression of genes implicated in the regulation of cell cycle and pro and anti apoptotic genes. Sp3 over-expression strongly reduces the development of tumours in nude mice confirming its pro-apoptotic potential in vivo. However, cells can survive to apoptosis through selective Sp3 cleavage by caspase. Sp3 induction in established tumours resulted in transient regression then progression. Progression coincides with re-accumulation of the full length form of Sp3. Sp3 is over-expressed in tumour cell lines of different origins. The presence of high levels of the full-length form of Sp3 indicates a poor prognosis for overall survival of patients with head and neck tumours. CONCLUSIONS Full length Sp3 accumulation highlights bypass of tumour cell apoptotic capacities and is indicative of head and neck tumours aggressiveness.
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Affiliation(s)
- Khadija Essafi-Benkhadir
- University of Nice-Sophia Antipolis, Institute of Developmental Biology and Cancer Research UMR CNRS 6543, Centre Antoine Lacassagne, Nice, France
| | - Sébastien Grosso
- University of Nice-Sophia Antipolis, INSERM, U895, Cell Death Differentiation and Cancer Team, Equipe labellisée par la Ligue Nationale contre le Cancer, Faculty of Medicine, Nice, France
| | - Alexandre Puissant
- University of Nice-Sophia Antipolis, INSERM, U895, Cell Death Differentiation and Cancer Team, Equipe labellisée par la Ligue Nationale contre le Cancer, Faculty of Medicine, Nice, France
| | - Guillaume Robert
- University of Nice-Sophia Antipolis, INSERM, U895, Cell Death Differentiation and Cancer Team, Equipe labellisée par la Ligue Nationale contre le Cancer, Faculty of Medicine, Nice, France
| | - Makram Essafi
- University of Nice-Sophia Antipolis, INSERM, U576, Regulation of immunity and inflammatory reactions, Nice, France
| | - Marcel Deckert
- University of Nice-Sophia Antipolis, INSERM, U576, Regulation of immunity and inflammatory reactions, Nice, France
| | | | | | - Gérard Milano
- Oncopharmacology unit (EA 3836), Centre Antoine Lacassagne, Nice, France
| | - Patrick Auberger
- University of Nice-Sophia Antipolis, INSERM, U895, Cell Death Differentiation and Cancer Team, Equipe labellisée par la Ligue Nationale contre le Cancer, Faculty of Medicine, Nice, France
| | - Gilles Pagès
- University of Nice-Sophia Antipolis, Institute of Developmental Biology and Cancer Research UMR CNRS 6543, Centre Antoine Lacassagne, Nice, France
- * E-mail:
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Boutros T, Chevet E, Metrakos P. Mitogen-activated protein (MAP) kinase/MAP kinase phosphatase regulation: roles in cell growth, death, and cancer. Pharmacol Rev 2009; 60:261-310. [PMID: 18922965 DOI: 10.1124/pr.107.00106] [Citation(s) in RCA: 438] [Impact Index Per Article: 29.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Mitogen-activated protein kinase dual-specificity phosphatase-1 (also called MKP-1, DUSP1, ERP, CL100, HVH1, PTPN10, and 3CH134) is a member of the threonine-tyrosine dual-specificity phosphatases, one of more than 100 protein tyrosine phosphatases. It was first identified approximately 20 years ago, and since that time extensive investigations into both mkp-1 mRNA and protein regulation and function in different cells, tissues, and organs have been conducted. However, no general review on the topic of MKP-1 exists. As the subject matter pertaining to MKP-1 encompasses many branches of the biomedical field, we focus on the role of this protein in cancer development and progression, highlighting the potential role of the mitogen-activated protein kinase (MAPK) family. Section II of this article elucidates the MAPK family cross-talk. Section III reviews the structure of the mkp-1 encoding gene, and the known mechanisms regulating the expression and activity of the protein. Section IV is an overview of the MAPK-specific dual-specificity phosphatases and their role in cancer. In sections V and VI, mkp-1 mRNA and protein are examined in relation to cancer biology, therapeutics, and clinical studies, including a discussion of the potential role of the MAPK family. We conclude by proposing an integrated scheme for MKP-1 and MAPK in cancer.
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Affiliation(s)
- Tarek Boutros
- Department of Surgery, Royal Victoria Hospital, McGill University, 687 Pine Ave. W., Montreal, QC H3A1A1, Canada.
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Morrison DJ, Kim MKH, Berkofsky-Fessler W, Licht JD. WT1 induction of mitogen-activated protein kinase phosphatase 3 represents a novel mechanism of growth suppression. Mol Cancer Res 2008; 6:1225-31. [PMID: 18644985 DOI: 10.1158/1541-7786.mcr-08-0078] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In its role as a tumor suppressor, WT1 transactivates several genes that are regulators of cell growth and differentiation pathways. For instance, WT1 induces the expression of the cell cycle regulator p21, the growth-regulating glycoprotein amphiregulin, the proapoptotic gene Bak, and the Ras/mitogen-activated protein kinase (MAPK) inhibitor Sprouty1. Here, we show that WT1 transactivates another important negative regulator of the Ras/MAPK pathway, MAPK phosphatase 3 (MKP3). In a WT1-inducible cell line that exhibits decreased cell growth and increased apoptosis on expression of WT1, microarray analysis showed that MKP3 is the most highly induced gene. This was confirmed by real-time PCR where MKP3 and other members of the fibroblast growth factor 8 syn expression group, which includes Sprouty 1 and the Ets family of transcription factors, were induced rapidly following WT1 expression. WT1 induction was associated with a block in the phosphorylation of extracellular signal-regulated kinase in response to epidermal growth factor stimulation, an effect mediated by MKP3. In the presence of a dominant-negative MKP3, WT1 could no longer block phosphorylation of extracellular signal-regulated kinase. Lastly, when MKP3 expression is down-regulated by short hairpin RNA, WT1 is less able to block Ras-mediated transformation of 3T3 cells.
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Affiliation(s)
- Debra J Morrison
- Division of Hematology/Oncology, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611, USA
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Abstract
There are ten mitogen-activated protein kinase (MAPK) phosphatases (MKPs) that act as negative regulators of MAPK activity in mammalian cells and these can be subdivided into three groups. The first comprises DUSP1/MKP-1, DUSP2/PAC1, DUSP4/MKP-2 and DUSP5/hVH-3, which are inducible nuclear phosphatases. With the exception of DUSP5, these MKPs display a rather broad specificity for inactivation of the ERK, p38 and JNK MAP kinases. The second group contains three closely related ERK-specific and cytoplasmic MKPs encoded by DUSP6/MKP-3, DUSP7/MKP-X and DUSP9/MKP-4. The final group consists of three MKPs DUSP8/hVH-5, DUSP10/MKP-5 and DUSP16/MKP-7 all of which preferentially inactivate the stress-activated p38 and JNK MAP kinases. Abnormal MAPK signalling will have important consequences for processes critical to the development and progression of human cancer. In addition, MAPK signalling also plays a key role in determining the response of tumour cells to conventional cancer therapies. The emerging roles of the dual-specificity MKPs in the regulation of MAPK activities in normal tissues has highlighted the possible pathophysiological consequences of either loss (or gain) of function of these enzymes as part of the oncogenic process. This review summarises the current evidence implicating the dual-specificity MKPs in the initiation and development of cancer and also on the outcome of treatment.
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Affiliation(s)
- Stephen M Keyse
- Cancer Research UK Stress Response Laboratory, Biomedical Research Centre, Level 5, Ninewells Hospital and Medical School, Dundee, UK.
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17
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Görlach A, Kietzmann T. Superoxide and derived reactive oxygen species in the regulation of hypoxia-inducible factors. Methods Enzymol 2008; 435:421-46. [PMID: 17998067 DOI: 10.1016/s0076-6879(07)35022-2] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Superoxide and its derived reactive oxygen species (ROS) have been considered for a long time to be generated as toxic byproducts of metabolic events. More recently, it has been acknowledged that ROS generated in low amounts are also able to act as signaling molecules in a variety of responses. One of the major pathways regulated by the ambient concentration of oxygen relies on the activity of hypoxia-inducible transcription factors (HIF). Originally described to be only induced and activated under hypoxia, accumulating evidence suggests that HIFs play a more general role in the response to a variety of cellular activators and stressors, many of which use ROS as signal transducers. Indeed, ROS have been found to modulate the levels of HIF not only under hypoxia, but also in response to many factors and under different stress conditions. However, the underlying regulatory mechanisms by which superoxide and derived ROS control HIF are only slowly beginning to be elucidated. We summarize here current knowledge about the mechanisms by which ROS can regulate HIF and give additional information about useful methods to determine ROS under various conditions.
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Affiliation(s)
- Agnes Görlach
- Experimental Pediatric Cardiology, German Heart Center Munich, Munich, Germany
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18
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Pulido R, van Huijsduijnen RH. Protein tyrosine phosphatases: dual-specificity phosphatases in health and disease. FEBS J 2008; 275:848-66. [DOI: 10.1111/j.1742-4658.2008.06250.x] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Abstract
MAP kinases phosphatases (MKPs) belong to the dual-specificity phosphatase family (DUSP) and dephosphorylate phosphothreonine and phosphotyrosine within MAP kinases. We had previously shown that DUSP6/MKP-3 was phosphorylated and degraded upon growth factor stimulation, in a MEK-dependent manner. Here we show that another pathway involved in growth factor signaling, the PI3K/mTOR signaling pathway, accounts for a part of the phosphorylation and degradation of DUSP6 induced by serum growth factors, as evidenced by experiments using pharmacological inhibitors of PI3 kinase and mammalian target of rapamycin (mTOR). Moreover, specific agonists of the mTOR pathway, such as amino acids or insulin/IGF-1, which do not activate extracellular signal regulated kinases (ERKs) in our cellular model, were also able to induce the phosphorylation and degradation of DUSP6. However, a basal activity of MEK was required for the mTOR pathway-mediated phosphorylation to occur. Mutagenesis studies identified serine 159 within DUSP6 as the target of the mTOR pathway. The ERK phosphatase DUSP6 may thus constitute a novel branch-point of the crosstalk between two major signaling pathways induced by growth factors, the MEK/ERK pathway and the PI3K/mTOR pathway.
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20
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Pagès G. Sp3-mediated VEGF regulation is dependent on phosphorylation by extra-cellular signals regulated kinases (Erk). J Cell Physiol 2008; 213:454-63. [PMID: 17685427 DOI: 10.1002/jcp.21104] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We have previously demonstrated that phosphorylation by Erk of Sp1 was essential for its full activity in the context of the VEGF promoter. Here, we show that Sp3, which, as Sp1, belongs to the GC-rich binding transcription factor family, is also phosphorylated by Erk in vitro on serine 73. We have established cell lines in which expression of wild-type Sp3 or a serine 73 to alanine (S73A) mutant is controlled by tetracycline. One of these cells lines also express the Raf:ER chimera which permits stimulation of Erk by tamoxifen. Difference in electrophoretic mobility and antibody directed against the phosphorylated serine 73 demonstrate that it is phosphorylated in vivo. Wild-type Sp3 half-life is increased upon Erk activation but the S73 is poorly implicated in this mechanism suggesting that Erk-dependent Sp3 stability depends on other(s) domain(s) of the protein. Electro-mobility shift assays and utilization of Gal4/Sp3 chimeric proteins show that Erk does not alter Sp3 DNA binding capacity but enhances its transcriptional activity. The S73A mutant Sp3 posses a reduced activity in Erk-stimulated cells. In the inducible cell lines, expression of wild-type form of Sp3 increases VEGF production whereas the S73A form has a reduced potential reflecting its lower transcriptional activity. Altogether our results described a new link between constitutive Erk activity and the regulation of VEGF expression two common denominators implicated in tumor angiogenesis.
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Affiliation(s)
- Gilles Pagès
- Institute of Signalling, Developmental Biology and Cancer Research UMR CNRS 6543, University of Nice-Sophia Antipolis Equipe labellisée Ligue Nationale contre le Cancer, France.
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21
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Abstract
The mitogen-activated protein kinase (MAPK) phosphatases (MKPs) are a family of dual-specificity protein phosphatases that dephosphorylate both phospho-threonine and phospho-tyrosine residues in MAP kinases, including the c-Jun N-terminal protein kinase (JNK)/stress-activated protein kinase (SAPK), the p38 MAPK, and the extracellular signal-related kinase (ERK). Since phosphorylation is required for the activation of MAP kinases, dephosphorylation by MKPs inhibits MAPK activity, thereby negatively regulating MAPK signaling. It is known that deregulation of MAPK signaling is the most common alteration in human cancers. Recent studies have suggested that MKPs play an important role not only in the development of cancers, but also in the response of cancer cells to chemotherapy. Thus, understanding the roles of MKPs in the development of cancer and their impact on chemotherapy can be exploited for therapeutic benefits for the treatment of human cancer.
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Affiliation(s)
- Gen Sheng Wu
- Program in Molecular Biology and Genetics, Department of Pathology, Karmanos Cancer Institute, Wayne State University School of Medicine, Detroit, MI 48201, USA.
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22
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Beauclair S, Formento P, Fischel JL, Lescaut W, Largillier R, Chamorey E, Hofman P, Ferrero JM, Pagès G, Milano G. Role of the HER2 [Ile655Val] genetic polymorphism in tumorogenesis and in the risk of trastuzumab-related cardiotoxicity. Ann Oncol 2007; 18:1335-41. [PMID: 17693647 DOI: 10.1093/annonc/mdm181] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND To examine the impact of a frequent her2 gene polymorphism (Ile655Val) on tumor growth and on the pharmacodynamics of treatment by trastuzumab. PATIENTS AND METHODS Experimental study: The growth characteristics of cells expressing the Ile or Val isoform were examined in vitro and after injection into nude mice. The effect of trastuzumab was determined in both experimental models. Clinical study: 61 patients with advanced breast cancers and treated by trastuzumab were genotyped for HER2 by PCR-RFLP. The influence of HER2 genotype on the trastuzumab treatment was examined. RESULTS Experimental study: HER2-expressing cells acquired the characteristics of tumor cells. The Val isoform-expressing cells showed the highest growth capacity and developed aggressive tumors sensitive to trastuzumab. Clinical study: There was no link between tumor response or survival and HER2 genotype. All cases of treatment-related cardiotoxicity were found in the Ile/Val group and there was no cardiac toxicity in the Val/Val and Ile/Ile patients. CONCLUSIONS This study establishes a clear-cut difference between the two HER2 isoforms regarding their tumorogenic potential with an advantage for the Val/HER2 isoform. In breast cancer patients treated with trastuzumab, the presence of a Val allele may constitute a risk factor for cardiac toxicity.
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MESH Headings
- Adult
- Aged
- Aged, 80 and over
- Animals
- Antibodies, Monoclonal/adverse effects
- Antibodies, Monoclonal, Humanized
- Antineoplastic Agents/adverse effects
- Base Sequence
- Blotting, Western
- Breast Neoplasms/drug therapy
- Breast Neoplasms/genetics
- Breast Neoplasms/pathology
- Cell Transformation, Neoplastic/genetics
- Female
- Heart/drug effects
- Heart Diseases/chemically induced
- Humans
- Immunohistochemistry
- Mice
- Mice, Nude
- Middle Aged
- Molecular Sequence Data
- Mutagenesis, Site-Directed
- Neoplasms, Experimental/drug therapy
- Neoplasms, Experimental/genetics
- Neoplasms, Experimental/pathology
- Polymerase Chain Reaction
- Polymorphism, Genetic
- Polymorphism, Restriction Fragment Length
- Protein Isoforms/genetics
- Receptor, ErbB-2/genetics
- Transfection
- Trastuzumab
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Affiliation(s)
- S Beauclair
- Oncopharmacology unit (EA 3836), Centre Antoine Lacassagne, Nice, France
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23
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Microtubule Disruption and Tumor Suppression by Mitogen-Activated Protein Kinase Phosphatase 4. Cancer Res 2007; 67:10711-9. [DOI: 10.1158/0008-5472.can-07-1968] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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24
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Wattenberg EV. Palytoxin: exploiting a novel skin tumor promoter to explore signal transduction and carcinogenesis. Am J Physiol Cell Physiol 2006; 292:C24-32. [PMID: 16855216 PMCID: PMC1769420 DOI: 10.1152/ajpcell.00254.2006] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Palytoxin is a novel skin tumor promoter, which has been used to help probe the role of different types of signaling mechanisms in carcinogenesis. The multistage mouse skin model indicates that tumor promotion is an early, prolonged, and reversible phase of carcinogenesis. Understanding the molecular mechanisms underlying tumor promotion is therefore important for developing strategies to prevent and treat cancer. Naturally occurring tumor promoters that bind to specific cellular receptors have proven to be useful tools for investigating important biochemical events in multistage carcinogenesis. For example, the identification of protein kinase C as the receptor for the prototypical skin tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) (also called phorbol 12-myristate 13-acetate, PMA) provided key evidence that tumor promotion involves the aberrant modulation of signaling cascades that govern cell fate and function. The subsequent discovery that palytoxin, a marine toxin isolated from zoanthids (genus Palythoa), is a potent skin tumor promoter yet does not activate protein kinase C indicated that investigating palytoxin action could help reveal new aspects of tumor promotion. Interestingly, the putative receptor for palytoxin is the Na(+),K(+)-ATPase. This review focuses on palytoxin-stimulated signaling and how palytoxin has been used to investigate alternate biochemical mechanisms by which important targets in carcinogenesis can be modulated.
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Affiliation(s)
- Elizabeth V Wattenberg
- Division of Environmental Health Sciences, School of Public Health, University of Minnesota, Mayo Mail Code #807, 420 Delaware Street SE, Minneapolis, MN 55455, USA.
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25
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Kietzmann T, Görlach A. Reactive oxygen species in the control of hypoxia-inducible factor-mediated gene expression. Semin Cell Dev Biol 2006; 16:474-86. [PMID: 15905109 DOI: 10.1016/j.semcdb.2005.03.010] [Citation(s) in RCA: 215] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Reactive oxygen species (ROS) have long been considered as cytotoxic. However, recent evidence indicates a prominent role of ROS as signaling molecules in the response to hormones, growth and coagulation factors, cytokines and other factors as well as to changes in oxygen tension. The hypoxia-inducible transcription factors (HIFs) are key players in the cellular response to changes in oxygen tension. Recently, HIFs have also been shown to respond to the above-mentioned non-hypoxic stimuli. In this article, the role of ROS in the regulation of HIF-1 under hypoxic and non-hypoxic conditions is summarized.
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Affiliation(s)
- Thomas Kietzmann
- Faculty of Chemistry, Department of Biochemistry, Erwin-Schrödinger-Strasse, University of Kaiserslautern, 67663 Kaiserslautern, Germany
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26
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Griguer CE, Oliva CR, Kelley EE, Giles GI, Lancaster JR, Gillespie GY. Xanthine oxidase-dependent regulation of hypoxia-inducible factor in cancer cells. Cancer Res 2006; 66:2257-63. [PMID: 16489029 DOI: 10.1158/0008-5472.can-05-3364] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
During chemical hypoxia induced by cobalt chloride (CoCl2), hypoxia-inducible factor 1alpha (HIF1-alpha) mediates the induction of a variety of genes including erythropoietin and vascular endothelial growth factor. We used glioma cells with oxidative phosphorylation-dependent (D54-MG) and glycolytic-dependent (U251-MG) phenotypes to monitor HIF1-alpha regulation in association with redox responsiveness to CoCl2 treatment. We showed that CoCl2 increased xanthine oxidase (XO)-derived reactive oxygen species (ROS), which causes accumulation of HIF1-alpha protein in U251-MG cells. Under these conditions, blockade of XO activity by pharmacologic (N-acetyl-L-cysteine or allopurinol) or molecular (by small interfering RNA) approaches significantly attenuated HIF1-alpha expression. Exogenous H2O2 stabilizes HIF1-alpha protein. XO was present in these cells and was the primary source of free radicals. We also showed higher XO activity in cells exposed to CoCl2 compared with cells grown in normoxia. From the experiments shown here, we concluded that ROS were indeed generated in D54-MG cells exposed to CoCl2 but it was unlikely that ROS participated in the hypoxic signal transduction pathways in this cell type. Possibly, cell type-dependent and stimulus-dependent factors may control ROS dependency or redox sensitivity of HIF1-alpha and thus HIF1-alpha activation either directly or by induction of specific signaling cascades. Our findings reveal that XO-derived ROS is a novel and critical component of HIF1-alpha regulation in U251-MG cells, pointing toward a more general role of this transcription factor in tumor progression.
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Affiliation(s)
- Corinne E Griguer
- Department of Surgery, University of Alabama at Birmingham, Birmingham, Alabama 35294-0005, USA.
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27
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Bourcier C, Jacquel A, Hess J, Peyrottes I, Angel P, Hofman P, Auberger P, Pouysségur J, Pagès G. p44 Mitogen-Activated Protein Kinase (Extracellular Signal-Regulated Kinase 1)–Dependent Signaling Contributes to Epithelial Skin Carcinogenesis. Cancer Res 2006; 66:2700-7. [PMID: 16510590 DOI: 10.1158/0008-5472.can-05-3129] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Extracellular signal-regulated kinases (ERK) regulate cellular functions in response to a variety of external signals. However, the specific functions of individual ERK isoforms are largely unknown. Hence, we have investigated the specific function of ERK1 in skin homeostasis and tumorigenesis in ERK1 knockout mice. They spontaneously develop cutaneous lesions and hyperkeratosis with epidermis thickness. Skin hyperproliferation and inflammation induced by application of 12-O-tetradecanoylphorbol-13-acetate (TPA) is strongly reduced in mutant mice. ERK1(-/-) mice are resistant to development of skin papillomas induced by 7,12-dimethylbenz(a)anthracene (DMBA) and promoted by TPA. Tumor appearance was delayed, their formation was less frequent, and their number and size were reduced. Keratinocytes obtained from knockout mice showed reduced growth and resistance to apoptotic signals, accompanied by an impaired expression of genes implicated in growth control and invasiveness. These results highlight the importance of ERK1 in skin homeostasis and in the process of skin tumor development.
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Affiliation(s)
- Christine Bourcier
- Institute of Signaling, Developmental Biology and Cancer Research, UMR Centre National de la Recherche Scientifique, Nice, France
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28
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Marchetti S, Gimond C, Chambard JC, Touboul T, Roux D, Pouysségur J, Pagès G. Extracellular signal-regulated kinases phosphorylate mitogen-activated protein kinase phosphatase 3/DUSP6 at serines 159 and 197, two sites critical for its proteasomal degradation. Mol Cell Biol 2005; 25:854-64. [PMID: 15632084 PMCID: PMC543408 DOI: 10.1128/mcb.25.2.854-864.2005] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Mitogen-activated protein (MAP) kinase phosphatases (MKPs) are dual-specificity phosphatases that dephosphorylate phosphothreonine and phosphotyrosine residues within MAP kinases. Here, we describe a novel posttranslational mechanism for regulating MKP-3/Pyst1/DUSP6, a member of the MKP family that is highly specific for extracellular signal-regulated kinase 1 and 2 (ERK1/2) inactivation. Using a fibroblast model in which the expression of either MKP-3 or a more stable MKP-3-green fluorescent protein (GFP) chimera was induced by tetracycline, we found that serum induces the phosphorylation of MKP-3 and its subsequent degradation by the proteasome in a MEK1 and MEK2 (MEK1/2)-ERK1/2-dependent manner. In vitro phosphorylation assays using glutathione S-transferase (GST)-MKP-3 fusion proteins indicated that ERK2 could phosphorylate MKP-3 on serines 159 and 197. Tetracycline-inducible cell clones expressing either single or double serine mutants of MKP-3 or MKP-3-GFP confirmed that these two sites are targeted by the MEK1/2-ERK1/2 module in vivo. Double serine mutants of MKP-3 or MKP-3-GFP were more efficiently protected from degradation than single mutants or wild-type MKP-3, indicating that phosphorylation of either serine by ERK1/2 enhances proteasomal degradation of MKP-3. Hence, double mutation caused a threefold increase in the half-life of MKP-3. Finally, we show that the phosphorylation of MKP-3 has no effect on its catalytic activity. Thus, ERK1/2 exert a positive feedback loop on their own activity by promoting the degradation of MKP-3, one of their major inactivators in the cytosol, a situation opposite to that described for the nuclear phosphatase MKP-1.
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Affiliation(s)
- Sandrine Marchetti
- Institute of Signaling, Developmental Biology and Cancer Research, CNRS UMR 6543, Centre Antoine Lacassagne, 33 Ave. de Valombrose, 06189 Nice, France
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