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Wang F, Remke M, Bhat K, Wong ET, Zhou S, Ramaswamy V, Dubuc A, Fonkem E, Salem S, Zhang H, Hsieh TC, O'Rourke ST, Wu L, Li DW, Hawkins C, Kohane IS, Wu JM, Wu M, Taylor MD, Wu E. A microRNA-1280/JAG2 network comprises a novel biological target in high-risk medulloblastoma. Oncotarget 2015; 6:2709-24. [PMID: 25576913 PMCID: PMC4413612 DOI: 10.18632/oncotarget.2779] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2014] [Accepted: 11/19/2014] [Indexed: 01/23/2023] Open
Abstract
Over-expression of PDGF receptors (PDGFRs) has been previously implicated in high-risk medulloblastoma (MB) pathogenesis. However, the exact biological functions of PDGFRα and PDGFRβ signaling in MB biology remain poorly understood. Here, we report the subgroup specific expression of PDGFRα and PDGFRβ and their associated biological pathways in MB tumors. c-MYC, a downstream target of PDGFRβ but not PDGFRα, is involved in PDGFRβ signaling associated with cell proliferation, cell death, and invasion. Concurrent inhibition of PDGFRβ and c-MYC blocks MB cell proliferation and migration synergistically. Integrated analysis of miRNA and miRNA targets regulated by both PDGFRβ and c-MYC reveals that increased expression of JAG2, a target of miR-1280, is associated with high metastatic dissemination at diagnosis and a poor outcome in MB patients. Our study may resolve the controversy on the role of PDGFRs in MB and unveils JAG2 as a key downstream effector of a PDGFRβ-driven signaling cascade and a potential therapeutic target.
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Affiliation(s)
- Fengfei Wang
- Department of Pharmaceutical Sciences, North Dakota State University, Fargo, ND 58105, USA
| | - Marc Remke
- Arthur and Sonia Labatt Brain Tumor Research Centre, Program in Developmental and Stem Cell Biology, Hospital for Sick Children, University of Toronto, Toronto, ON M5G 1X8, Canada
| | - Kruttika Bhat
- Department of Pharmaceutical Sciences, North Dakota State University, Fargo, ND 58105, USA
| | - Eric T Wong
- Brain Tumor Center & Neuro-Oncology Unit, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
| | - Shuang Zhou
- Department of Pharmaceutical Sciences, North Dakota State University, Fargo, ND 58105, USA
| | - Vijay Ramaswamy
- Arthur and Sonia Labatt Brain Tumor Research Centre, Program in Developmental and Stem Cell Biology, Hospital for Sick Children, University of Toronto, Toronto, ON M5G 1X8, Canada
| | - Adrian Dubuc
- Arthur and Sonia Labatt Brain Tumor Research Centre, Program in Developmental and Stem Cell Biology, Hospital for Sick Children, University of Toronto, Toronto, ON M5G 1X8, Canada
| | - Ekokobe Fonkem
- Scott & White Neuroscience Institute, Texas A & M Health Science Center, Temple, TX 76508, USA
| | - Saeed Salem
- Department of Computer Sciences, North Dakota State University, Fargo, ND 58105, USA
| | - Hongbing Zhang
- Department of Physiology, State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100073, China
| | - Tze-Chen Hsieh
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY 10595, USA
| | - Stephen T O'Rourke
- Department of Pharmaceutical Sciences, North Dakota State University, Fargo, ND 58105, USA
| | - Lizi Wu
- Department of Molecular Genetics and Microbiology, Shands Cancer Center, University of Florida, Gainesville, FL 32610, USA
| | - David W Li
- Department of Ophthalmology & Visual Sciences, College of Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Cynthia Hawkins
- Division of Pathology, Hospital for Sick Children, Toronto, ON M5G 1X8, Canada
| | - Isaac S Kohane
- Informatics Program, Children's Hospital Boston, Harvard Medical School, Boston 02115, MA, USA
| | - Joseph M Wu
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY 10595, USA
| | - Min Wu
- Department of Biochemistry and Molecular Biology, University of North Dakota, Grand Forks, ND 58202, USA
| | - Michael D Taylor
- Arthur and Sonia Labatt Brain Tumor Research Centre, Program in Developmental and Stem Cell Biology, Hospital for Sick Children, University of Toronto, Toronto, ON M5G 1X8, Canada
| | - Erxi Wu
- Department of Pharmaceutical Sciences, North Dakota State University, Fargo, ND 58105, USA
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Windischhofer W, Huber E, Rossmann C, Semlitsch M, Kitz K, Rauh A, Devaney T, Leis HJ, Malle E. LPA-induced suppression of periostin in human osteosarcoma cells is mediated by the LPA(1)/Egr-1 axis. Biochimie 2012; 94:1997-2005. [PMID: 22659570 PMCID: PMC3407874 DOI: 10.1016/j.biochi.2012.05.023] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2011] [Accepted: 05/07/2012] [Indexed: 01/30/2023]
Abstract
Lysophosphatidic acid (LPA), a naturally occurring bioactive phospholipid, mediates a multitude of (patho)physiological events including activation of mitogen-activated protein kinases (MAPKs). As LPA may induce cellular reponses in human osteosarcoma, the present study aimed at investigating expression of various LPA receptors, LPA-mediated activation of MAPK via G-protein coupling, and expression of early response genes in a cellular model for human osteosarcoma. We show that MG-63 cells express three members of the endothelial differentiation gene (Edg) family of G-protein coupled receptor transcripts (LPA(1-3)) but only two (LPA(4/5)) out of three members of the non-Edg family LPA receptor transcripts. Stimulation of MG-63 cells with LPA or synthetic LPA receptor agonists resulted in p42/44 MAPK phosphorylation via LPA(1)-LPA(3) receptors. Using pharmacological inhibitors, we show that LPA-mediated phosphorylation of p42/44 MAPK by LPA receptor engagement is transmitted by G(αi)-dependent pathways through the Src family of tyrosine kinases. As a consequence, a rapid and transient upregulation of the zinc finger transcription factor early growth response-1 (Egr-1) was observed. Egr-1 expression was strictly mediated via G(αi)/Src/p42/44 MAPK pathway; no involvement of the G(αq/11)/PLC/PKC or the PLD/PI3 kinase/Akt pathways was found. LPA-induced expression of functional Egr-1 in MG-63 cells could be confirmed by electrophoretic mobility shift assay. LPA-induced Egr-1 upregulation was accompanied by a time-dependent decrease of periostin (previously called osteoblast-specific factor 2), a cell adhesion protein for pre-osteoblasts. Silencing of LPA(1) and/or Egr-1 in MG-63 cells reversed LPA-mediated suppression of periostin. We here demonstrate a crosslink between Egr-1 and periostin in cancer cells, in particular in human osteosarcoma.
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Affiliation(s)
- Werner Windischhofer
- Medical University of Graz, University Clinic of Pediatrics and Adolescent Medicine, Research Unit of Osteological Research and Analytical Mass Spectrometry, Auenbruggerplatz 30, A-8036 Graz, Austria.
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Toda T, Tamamoto T, Sadi AM, Kiyuna M, Nakashima Y, Inoue Y. Expression of platelet-derived growth factor and c-myc in atherosclerotic lesions in cholesterol-fed chickens: immunohistochemical and in situ hybridization study. Virchows Arch 1994; 425:55-61. [PMID: 7921414 DOI: 10.1007/bf00193949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Immunohistochemical examination showed no significant expression of platelet-derived growth factor-A (PDGF-A), PDGF-B, PDGF receptors, or of c-myc in the thoracic and abdominal aortas of normal roosters. In cholesterol-fed roosters, intense immunohistochemical reaction for PDGF-B, PDGF receptor, and c-myc was seen in the lipid-rich thickened intimal lesions of the thoracic and abdominal aortas while no significant immunoreaction for PDGF-A was demonstrated in the same lesions. In accordance with immunohistochemical findings, in situ hybridization demonstrated a significant level of expression of PDGF-B, PDGF-A receptor, PDGF-B receptor, and c-myc genes in proliferating intimal cells of the thoracic and abdominal aortas. These results suggest that coordinate actions of PDGF-B and c-myc play an important role in proliferation of intimal cells in the developing atherosclerotic lesions in chickens.
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Affiliation(s)
- T Toda
- Department of Clinical Laboratory, School of Medicine, University of the Ryukyus, Okinawa, Japan
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Masson N, Ellis M, Goodbourn S, Lee KA. Cyclic AMP response element-binding protein and the catalytic subunit of protein kinase A are present in F9 embryonal carcinoma cells but are unable to activate the somatostatin promoter. Mol Cell Biol 1992; 12:1096-106. [PMID: 1347642 PMCID: PMC369541 DOI: 10.1128/mcb.12.3.1096-1106.1992] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The cyclic AMP (cAMP) response elements (CREs) of the somatostatin and vasoactive intestinal peptide (VIP) promoters contain binding sites for CRE-binding protein (CREB) that are essential for cAMP-regulated transcription. Using F9 embryonal carcinoma cells, we show that the somatostatin and VIP promoters exhibit a differentiation-dependent cAMP response, demonstrating that these promoters are regulated by transcription factors that become active during differentiation. Lack of cAMP responsiveness of the somatostatin promoter in undifferentiated cells is not due to the absence of known positive-acting factors (the catalytic subunit of protein kinase A [cPKA] and CREB) or a general inhibition of protein kinase A activity. Since overexpression of exogenous cPKA and CREB is sufficient to activate the somatostatin promoter in undifferentiated cells, these findings suggest that a negative factor(s) represses endogenous cPKA and CREB. In contrast to their effects on somatostatin, exogenous CREB and cPKA do not activate the VIP promoter. Thus, despite coregulation during differentiation and the ability to bind CREB, the somatostatin and VIP promoters are not coordinately activated by CREB in undifferentiated F9 cells.
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Affiliation(s)
- N Masson
- Gene Activation Laboratory, Imperial Cancer Research Fund, Clare Hall Laboratories, South Mimms, Hertfordshire, United Kingdom
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Cyclic AMP response element-binding protein and the catalytic subunit of protein kinase A are present in F9 embryonal carcinoma cells but are unable to activate the somatostatin promoter. Mol Cell Biol 1992. [PMID: 1347642 DOI: 10.1128/mcb.12.3.1096] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The cyclic AMP (cAMP) response elements (CREs) of the somatostatin and vasoactive intestinal peptide (VIP) promoters contain binding sites for CRE-binding protein (CREB) that are essential for cAMP-regulated transcription. Using F9 embryonal carcinoma cells, we show that the somatostatin and VIP promoters exhibit a differentiation-dependent cAMP response, demonstrating that these promoters are regulated by transcription factors that become active during differentiation. Lack of cAMP responsiveness of the somatostatin promoter in undifferentiated cells is not due to the absence of known positive-acting factors (the catalytic subunit of protein kinase A [cPKA] and CREB) or a general inhibition of protein kinase A activity. Since overexpression of exogenous cPKA and CREB is sufficient to activate the somatostatin promoter in undifferentiated cells, these findings suggest that a negative factor(s) represses endogenous cPKA and CREB. In contrast to their effects on somatostatin, exogenous CREB and cPKA do not activate the VIP promoter. Thus, despite coregulation during differentiation and the ability to bind CREB, the somatostatin and VIP promoters are not coordinately activated by CREB in undifferentiated F9 cells.
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