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Ou K, Zhang J, Jiao Y, Wang ZV, Scherer P, Kaestner KH. Overexpression of ST5, an activator of Ras, has no effect on β-cell proliferation in adult mice. Mol Metab 2018; 11:212-217. [PMID: 29650351 PMCID: PMC6001393 DOI: 10.1016/j.molmet.2018.03.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 03/15/2018] [Accepted: 03/19/2018] [Indexed: 01/27/2023] Open
Abstract
Objective Both Type I and Type II diabetes mellitus result from insufficient functional β-cell mass. Efforts to increase β-cell proliferation as a means to restore β-cell mass have been met with limited success. Suppression of Tumorigenicity 5 (ST5) activates Ras/Erk signaling in the presence of Epidermal Growth Factor (EGF). In the pancreatic islet, Ras/Erk signaling is required for augmented β-cell proliferation during pregnancy, suggesting that ST5 is an appealing candidate to enhance adult β-cell proliferation. We aimed to test the hypothesis that overexpression of ST5 drives adult β-cell proliferation. Methods We utilized a doxycycline-inducible bitransgenic mouse model to activate β-cell-specific expression of human ST5 in adult mice at will. Islet morphology, β-cell proliferation, and β-cell mass in control and ST5-overexpressing (ST5 OE) animals were analyzed by immunofluorescent staining, under basal and two stimulated metabolic states: pregnancy and streptozotocin (STZ)-induced β-cell loss. Results Doxycycline treatment resulted in robust ST5 overexpression in islets from 12-16 week-old ST5 OE animals compared to controls, without affecting the islet morphology and identity of the β-cells. Under both basal and metabolically stimulated pregnancy states, β-cell proliferation and mass were comparable in ST5 OE and control animals. Furthermore, there was no detectable difference in β-cell proliferation between ST5 OE and control animals in response to STZ-induced β-cell loss. Conclusions We successfully derived an inducible bitransgenic mouse model to overexpress ST5 specifically in β-cells. However, our findings demonstrate that ST5 overexpression by itself has no mitogenic effect on the adult β-cell under basal and metabolically challenged states. Hypothesized that overexpression of ST5 would drive adult β-cell proliferation due to its role in activating MAPK/ERK. Generated a doxycycline-inducible bitransgenic mouse model to activate β-cell-specific expression of ST5. ST5 overexpression has no mitogenic effect on adult β-cellsunder basal and metabolically challenged states.
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Affiliation(s)
- Kristy Ou
- Department of Genetics and Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.
| | - Jia Zhang
- Department of Genetics and Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.
| | - Yang Jiao
- Department of Genetics and Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Zhao V Wang
- Touchstone Diabetes Center, University of Texas Southwestern, Dallas, TX, 75390, USA
| | - Phillipp Scherer
- Touchstone Diabetes Center, University of Texas Southwestern, Dallas, TX, 75390, USA.
| | - Klaus H Kaestner
- Department of Genetics and Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.
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Ho JY, Hsu RJ, Wu CH, Liao GS, Gao HW, Wang TH, Yu CP. Reduced miR-550a-3p leads to breast cancer initiation, growth, and metastasis by increasing levels of ERK1 and 2. Oncotarget 2018; 7:53853-53868. [PMID: 27462780 PMCID: PMC5288226 DOI: 10.18632/oncotarget.10793] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 07/10/2016] [Indexed: 01/13/2023] Open
Abstract
Hyperactivation of the Ras/ERK pathway contributes to breast cancer initiation and progression, and recent evidence suggests aberrant signaling of miRNAs that regulate the Ras/ERK pathway play important roles during carcinogenesis and cancer progression. In this study, we demonstrate that miR-550a-3p expression is negatively correlated with levels of ERK1 and ERK2, two pivotal effectors in the Ras/ERK pathway. MiR-550a-3p gradually decreased during breast cancer initiation and progression and this reduction was a prognostic indicator of poorer overall survival (OS) and disease-free survival (DFS) among breast cancer patients. Our mechanistic studies demonstrated that miR-550a-3p exerts its tumor-suppressor role by directly repressing ERK1 and ERK2 protein expression, thereby suppressing the oncogenic ERK/RSK cascades, which reduced breast cancer cell viability, survival, migration, invasion, tumorigenesis, and metastasis. The inhibitory effects of miR-550a-3p were rescued by ectopic expression of ERK1 and/or ERK2. The novel connection between miR-550a-3p and ERK defines a new diagnostic and prognostic role for miR-550a-3p and highlights ERK inhibition as a candidate therapeutic target for breast cancers exhibiting hyperactivated Ras/ERK signaling.
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Affiliation(s)
- Jar-Yi Ho
- Department of Pathology, and Graduate Institute of Pathology and Parasitology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Ren-Jun Hsu
- Department of Pathology, and Graduate Institute of Pathology and Parasitology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.,Biobank Management Center of Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Chih-Hsi Wu
- Department of Pathology, and Graduate Institute of Pathology and Parasitology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Guo-Shiou Liao
- Department of Surgery, Tri-Service General Hospital, Taipei, Taiwan
| | - Hong-Wei Gao
- Department of Pathology, and Graduate Institute of Pathology and Parasitology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Tong-Hong Wang
- Tissue Bank, Chang Gung Memorial Hospital, Tao-Yuan, Taiwan
| | - Cheng-Ping Yu
- Department of Pathology, and Graduate Institute of Pathology and Parasitology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.,Biobank Management Center of Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
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Masgras I, Ciscato F, Brunati AM, Tibaldi E, Indraccolo S, Curtarello M, Chiara F, Cannino G, Papaleo E, Lambrughi M, Guzzo G, Gambalunga A, Pizzi M, Guzzardo V, Rugge M, Vuljan SE, Calabrese F, Bernardi P, Rasola A. Absence of Neurofibromin Induces an Oncogenic Metabolic Switch via Mitochondrial ERK-Mediated Phosphorylation of the Chaperone TRAP1. Cell Rep 2017; 18:659-672. [PMID: 28099845 DOI: 10.1016/j.celrep.2016.12.056] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 11/04/2016] [Accepted: 12/18/2016] [Indexed: 01/21/2023] Open
Abstract
Mutations in neurofibromin, a Ras GTPase-activating protein, lead to the tumor predisposition syndrome neurofibromatosis type 1. Here, we report that cells lacking neurofibromin exhibit enhanced glycolysis and decreased respiration in a Ras/ERK-dependent way. In the mitochondrial matrix of neurofibromin-deficient cells, a fraction of active ERK1/2 associates with succinate dehydrogenase (SDH) and TRAP1, a chaperone that promotes the accumulation of the oncometabolite succinate by inhibiting SDH. ERK1/2 enhances both formation of this multimeric complex and SDH inhibition. ERK1/2 kinase activity is favored by the interaction with TRAP1, and TRAP1 is, in turn, phosphorylated in an ERK1/2-dependent way. TRAP1 silencing or mutagenesis at the serine residues targeted by ERK1/2 abrogates tumorigenicity, a phenotype that is reverted by addition of a cell-permeable succinate analog. Our findings reveal that Ras/ERK signaling controls the metabolic changes orchestrated by TRAP1 that have a key role in tumor growth and are a promising target for anti-neoplastic strategies.
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Affiliation(s)
- Ionica Masgras
- CNR Institute of Neuroscience and Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
| | - Francesco Ciscato
- CNR Institute of Neuroscience and Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
| | - Anna Maria Brunati
- Department of Molecular Medicine, University of Padova, 35131 Padova, Italy
| | - Elena Tibaldi
- Department of Molecular Medicine, University of Padova, 35131 Padova, Italy
| | | | | | - Federica Chiara
- Department of Cardiac, Thoracic, and Vascular Sciences, University of Padova, 35128 Padova, Italy
| | - Giuseppe Cannino
- CNR Institute of Neuroscience and Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
| | - Elena Papaleo
- Computational Biology Laboratory, Unit of Statistics, Bioinformatics and Registry, Danish Cancer Society Research Center, 2100 Copenhagen, Denmark
| | - Matteo Lambrughi
- Computational Biology Laboratory, Unit of Statistics, Bioinformatics and Registry, Danish Cancer Society Research Center, 2100 Copenhagen, Denmark
| | - Giulia Guzzo
- CNR Institute of Neuroscience and Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
| | - Alberto Gambalunga
- Department of Cardiac, Thoracic, and Vascular Sciences, University of Padova, 35128 Padova, Italy
| | - Marco Pizzi
- Department of Medicine, University of Padova, 35128 Padova, Italy
| | | | - Massimo Rugge
- Department of Medicine, University of Padova, 35128 Padova, Italy
| | - Stefania Edith Vuljan
- Department of Cardiac, Thoracic, and Vascular Sciences, University of Padova, 35128 Padova, Italy
| | - Fiorella Calabrese
- Department of Cardiac, Thoracic, and Vascular Sciences, University of Padova, 35128 Padova, Italy
| | - Paolo Bernardi
- CNR Institute of Neuroscience and Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
| | - Andrea Rasola
- CNR Institute of Neuroscience and Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy.
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Timberlake AT, Furey CG, Choi J, Nelson-Williams C, Loring E, Galm A, Kahle KT, Steinbacher DM, Larysz D, Persing JA, Lifton RP; Yale Center for Genome Analysis. De novo mutations in inhibitors of Wnt, BMP, and Ras/ERK signaling pathways in non-syndromic midline craniosynostosis. Proc Natl Acad Sci U S A 2017; 114:E7341-7. [PMID: 28808027 DOI: 10.1073/pnas.1709255114] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Non-syndromic craniosynostosis (NSC) is a frequent congenital malformation in which one or more cranial sutures fuse prematurely. Mutations causing rare syndromic craniosynostoses in humans and engineered mouse models commonly increase signaling of the Wnt, bone morphogenetic protein (BMP), or Ras/ERK pathways, converging on shared nuclear targets that promote bone formation. In contrast, the genetics of NSC is largely unexplored. More than 95% of NSC is sporadic, suggesting a role for de novo mutations. Exome sequencing of 291 parent-offspring trios with midline NSC revealed 15 probands with heterozygous damaging de novo mutations in 12 negative regulators of Wnt, BMP, and Ras/ERK signaling (10.9-fold enrichment, P = 2.4 × 10-11). SMAD6 had 4 de novo and 14 transmitted mutations; no other gene had more than 1. Four familial NSC kindreds had mutations in genes previously implicated in syndromic disease. Collectively, these mutations contribute to 10% of probands. Mutations are predominantly loss-of-function, implicating haploinsufficiency as a frequent mechanism. A common risk variant near BMP2 increased the penetrance of SMAD6 mutations and was overtransmitted to patients with de novo mutations in other genes in these pathways, supporting a frequent two-locus pathogenesis. These findings implicate new genes in NSC and demonstrate related pathophysiology of common non-syndromic and rare syndromic craniosynostoses. These findings have implications for diagnosis, risk of recurrence, and risk of adverse neurodevelopmental outcomes. Finally, the use of pathways identified in rare syndromic disease to find genes accounting for non-syndromic cases may prove broadly relevant to understanding other congenital disorders featuring high locus heterogeneity.
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Caunt CJ, Kidger AM, Keyse SM. Visualizing and Quantitating the Spatiotemporal Regulation of Ras/ERK Signaling by Dual-Specificity Mitogen-Activated Protein Phosphatases (MKPs). Methods Mol Biol 2016; 1447:197-215. [PMID: 27514808 DOI: 10.1007/978-1-4939-3746-2_12] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The spatiotemporal regulation of the Ras/ERK pathway is critical in determining the physiological and pathophysiological outcome of signaling. Dual-specificity mitogen-activated protein kinase (MAPK) phosphatases (DUSPs or MKPs) are key regulators of pathway activity and may also localize ERK to distinct subcellular locations. Here we present methods largely based on the use of high content microscopy to both visualize and quantitate the subcellular distribution of activated (p-ERK) and total ERK in populations of mouse embryonic fibroblasts derived from mice lacking DUSP5, a nuclear ERK-specific MKP. Such methods in combination with rescue experiments using adenoviral vectors encoding wild-type and mutant forms of DUSP5 have allowed us to visualize specific defects in ERK regulation in these cells thus confirming the role of this phosphatase as both a nuclear regulator of ERK activity and localization.
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Abstract
NM23-H1 (also known as NME1) was the first identified metastasis suppressor, which displays a nucleoside diphosphate kinase (NDPK) and histidine protein kinase activity. NDPKs are linked to many processes, such as cell migration, proliferation, differentiation, but the exact mechanism whereby NM23-H1 inhibits the metastatic potential of cancer cells remains elusive. However, some recent data suggest that NM23-H1 may exert its anti-metastatic effect by blocking Ras/ERK signaling. In mammalian cell lines NDPK-mediated attenuation of Ras/ERK signaling occurs through phosphorylation (thus inactivation) of KSR (kinase suppressor of Ras) scaffolds. In this review I summarize our knowledge about KSR's function and its regulation in mammals and in C. elegans. Genetic studies in the nematode contributed substantially to our understanding of the function and regulation of the Ras pathway (i.e. KSR's discovery is also linked to the nematode). Components of the RTK/Ras/ERK pathway seem to be highly conserved between mammals and worms. NDK-1, the worm homolog of NM23-H1 affects Ras/MAPK signaling at the level of KSRs, and a functional interaction between NDK-1/NDPK and KSRs was first demonstrated in the worm in vivo. However, NDK-1 is a factor, which is necessary for proper MAPK activation, thus it activates rather than suppresses Ras/MAPK signaling in the worm. The contradiction between results in mammalian cell lines and in the worm regarding NDPKs' effect exerted on the outcome of Ras signaling might be resolved, if we better understand the function, structure and regulation of KSR scaffolds.
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Affiliation(s)
- Krisztina Takács-Vellai
- Department of Biological Anthropology, Eötvös Loránd University, Pázmány Péter stny. 1/C, H-1117 Budapest, Hungary
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