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Pashkova N, Peterson TA, Ptak CP, Winistorfer SC, Ahern CA, Shy ME, Piper RC. PMP22 associates with MPZ via their transmembrane domains and disrupting this interaction causes a loss-of-function phenotype similar to hereditary neuropathy associated with liability to pressure palsies (HNPP). BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.24.573255. [PMID: 38187781 PMCID: PMC10769442 DOI: 10.1101/2023.12.24.573255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
PMP22 and MPZ are major myelin proteins in the peripheral nervous system. MPZ is a single pass integral membrane protein with an extracellular immunoglobulin (Ig)-like domain and works as an adhesion protein to hold myelin wraps together across the intraperiod line. Loss of MPZ causes severe demyelinating Charcot-Marie-Tooth (CMT) peripheral neuropathy. PMP22 is an integral membrane tetraspan protein belonging to the Claudin superfamily. Homozygous loss of PMP22 also leads to severe demyelinating neuropathy, and duplication of wildtype PMP22 causes the most common form of CMT, CMT1A. Yet the molecular functions provided by PMP22 and how its alteration causes CMT are unknown. Here we find that these abundant myelin proteins form a strong and specific complex. Mutagenesis and domain swapping experiments reveal that these proteins interact through interfaces within their transmembrane domains. We also find that the PMP22 A67T patient variant that causes an HNPP (Hereditary neuropathy with pressure palsies) phenotype, reflecting a heterozygous loss-of-function, maps to this interface. The PMP22 A67T variant results in the specific loss of MPZ association with PMP22 without affecting PMP22 localization to the plasma membrane or its interactions with other proteins. These data define the molecular basis for the MPZ∼PMP22 interaction and indicate that the MPZ∼PMP22 complex fulfills an important function in myelinating cells.
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Jiang L, Cao D, Yeung WSB, Lee KF. Single-Cell RNA-Sequencing Reveals Interactions between Endometrial Stromal Cells, Epithelial Cells, and Lymphocytes during Mouse Embryo Implantation. Int J Mol Sci 2022; 24:ijms24010213. [PMID: 36613656 PMCID: PMC9820401 DOI: 10.3390/ijms24010213] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 12/20/2022] [Accepted: 12/20/2022] [Indexed: 12/25/2022] Open
Abstract
The decidualization of endometrial stromal cells (ESCs) is an essential process facilitating embryo implantation. However, the roles of non-decidualized and decidualized ESCs in regulating the microenvironment of a receptive endometrium remain unclear. We investigated single-cell transcriptomic changes in the uterus of a CD-1 mouse model at the post-implantation stage. The implantation and inter-implantation sites of the uteruses of pregnant mice at 4.5 and 5.5 days post-coitum were dissected for single-cell RNA sequencing. We identified eight cell types: epithelial cells, stromal cells, endothelial cells, mesothelial cells, lymphocytes, myocytes, myeloids, and pericytes. The ESC transcriptome suggests that the four ESC subtypes are involved in the extracellular remodeling during implantation. The trajectory plot of ESC subtypes indicates embryo implantation that involves a differentiation pathway from undifferentiated ESCs (ESC 1) to decidualized ESCs (DEC ESCs), with distinct signaling pathways between the ESC subtypes. Furthermore, the ligand-receptor analysis suggests that ESCs communicate with epithelial cells and immune cells through nectin and ICAM signaling. Collectively, both decidualized and non-decidualized ESCs may regulate the endometrial microenvironment for optimal endometrial receptivity and immune tolerance. This study provides insights on the molecular and cellular characteristics of mouse ESCs in modulating the epithelial and lymphocyte functions during early embryo implantation.
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Affiliation(s)
- Luhan Jiang
- Department of Obstetrics and Gynaecology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Dandan Cao
- Shenzhen Key Laboratory of Fertility Regulation, The University of Hong Kong-Shenzhen Hospital, Futian District, Shenzhen 518053, China
| | - William S. B. Yeung
- Department of Obstetrics and Gynaecology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
- Shenzhen Key Laboratory of Fertility Regulation, The University of Hong Kong-Shenzhen Hospital, Futian District, Shenzhen 518053, China
| | - Kai-Fai Lee
- Department of Obstetrics and Gynaecology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
- Shenzhen Key Laboratory of Fertility Regulation, The University of Hong Kong-Shenzhen Hospital, Futian District, Shenzhen 518053, China
- Correspondence: ; Fax: +852-2816-1947
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Zhang N, Zhu HP, Huang W, Wen X, Xie X, Jiang X, Peng C, Han B, He G. Unraveling the structures, functions and mechanisms of epithelial membrane protein family in human cancers. Exp Hematol Oncol 2022; 11:69. [PMID: 36217151 PMCID: PMC9552464 DOI: 10.1186/s40164-022-00321-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Accepted: 09/20/2022] [Indexed: 02/07/2023] Open
Abstract
Peripheral myelin protein 22 (PMP22) and epithelial membrane proteins (EMP-1, -2, and -3) belong to a small hydrophobic membrane protein subfamily, with four transmembrane structures. PMP22 and EMPs are widely expressed in various tissues and play important roles in cell growth, differentiation, programmed cell death, and metastasis. PMP22 presents its highest expression in the peripheral nerve and participates in normal physiological and pathological processes of the peripheral nervous system. The progress of molecular genetics has shown that the genetic changes of the PMP22 gene, including duplication, deletion, and point mutation, are behind various hereditary peripheral neuropathies. EMPs have different expression patterns in diverse tissues and are closely related to the risk of malignant tumor progression. In this review, we focus on the four members in this protein family which are related to disease pathogenesis and discuss gene mutations and post-translational modification of them. Further research into the interactions between structural alterations and function of PMP22 and EMPs will help understand their normal physiological function and role in diseases and might contribute to developing novel therapeutic tools.
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Affiliation(s)
- Nan Zhang
- State Key Laboratory of Southwestern Chinese Medicine Resources, School of Pharmacy, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Hong-Ping Zhu
- State Key Laboratory of Southwestern Chinese Medicine Resources, School of Pharmacy, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China.,Antibiotics Research and Re‑Evaluation Key Laboratory of Sichuan Province, Sichuan Industrial Institute of Antibiotics, Chengdu University, Chengdu, 610106, China
| | - Wei Huang
- State Key Laboratory of Southwestern Chinese Medicine Resources, School of Pharmacy, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Xiang Wen
- Department of Dermatology, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Xin Xie
- State Key Laboratory of Southwestern Chinese Medicine Resources, School of Pharmacy, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Xian Jiang
- Department of Dermatology, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China.,Laboratory of Dermatology, Clinical Institute of Inflammation and Immunology (CIII), Frontiers Science Center for Disease-Related Molecular Network and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center of Biotherapy, Chengdu, 610041, China
| | - Cheng Peng
- State Key Laboratory of Southwestern Chinese Medicine Resources, School of Pharmacy, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Bo Han
- State Key Laboratory of Southwestern Chinese Medicine Resources, School of Pharmacy, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China.
| | - Gu He
- Department of Dermatology, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China. .,Laboratory of Dermatology, Clinical Institute of Inflammation and Immunology (CIII), Frontiers Science Center for Disease-Related Molecular Network and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center of Biotherapy, Chengdu, 610041, China.
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Boutary S, Echaniz-Laguna A, Adams D, Loisel-Duwattez J, Schumacher M, Massaad C, Massaad-Massade L. Treating PMP22 gene duplication-related Charcot-Marie-Tooth disease: the past, the present and the future. Transl Res 2021; 227:100-111. [PMID: 32693030 DOI: 10.1016/j.trsl.2020.07.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 07/02/2020] [Accepted: 07/15/2020] [Indexed: 12/30/2022]
Abstract
Charcot-Marie-Tooth (CMT) disease is the most frequent inherited neuropathy, affecting 1/1500 to 1/10000. CMT1A represents 60%-70% of all CMT and is caused by a duplication on chromosome 17p11.2 leading to an overexpression of the Peripheral Myelin Protein 22 (PMP22). PMP22 gene is under tight regulation and small changes in its expression influences myelination and affect motor and sensory functions. To date, CMT1A treatment is symptomatic and classic pharmacological options have been disappointing. Here, we review the past, present, and future treatment options for CMT1A, with a special emphasis on the highly promising potential of PMP22-targeted small interfering RNA and antisense oligonucleotides.
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Affiliation(s)
- Suzan Boutary
- U 1195, INSERM and Paris-Saclay University, Le Kremlin-Bicêtre, France
| | - Andoni Echaniz-Laguna
- U 1195, INSERM and Paris-Saclay University, Le Kremlin-Bicêtre, France; Neurology Department, AP-HP, Paris-Saclay Universityand French Referent Center for Familial Amyloid Polyneuropathy and Other Rare Peripheral Neuropathies (CRMR-NNERF), Bicêtre Hospital, Le Kremlin-Bicêtre, France
| | - David Adams
- U 1195, INSERM and Paris-Saclay University, Le Kremlin-Bicêtre, France; Neurology Department, AP-HP, Paris-Saclay Universityand French Referent Center for Familial Amyloid Polyneuropathy and Other Rare Peripheral Neuropathies (CRMR-NNERF), Bicêtre Hospital, Le Kremlin-Bicêtre, France
| | - Julien Loisel-Duwattez
- U 1195, INSERM and Paris-Saclay University, Le Kremlin-Bicêtre, France; Neurology Department, AP-HP, Paris-Saclay Universityand French Referent Center for Familial Amyloid Polyneuropathy and Other Rare Peripheral Neuropathies (CRMR-NNERF), Bicêtre Hospital, Le Kremlin-Bicêtre, France
| | | | - Charbel Massaad
- Faculty of Basic and Biomedical Sciences, Paris Descartes University, INSERM UMRS 1124, Paris, France
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Roberts O, Paraoan L. PERP-ing into diverse mechanisms of cancer pathogenesis: Regulation and role of the p53/p63 effector PERP. Biochim Biophys Acta Rev Cancer 2020; 1874:188393. [PMID: 32679166 DOI: 10.1016/j.bbcan.2020.188393] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Revised: 07/11/2020] [Accepted: 07/12/2020] [Indexed: 12/20/2022]
Abstract
The tetraspan plasma membrane protein PERP (p53 apoptosis effector related to PMP22) is a lesser-known transcriptional target of p53 and p63. A member of the PMP22/GAS3/EMP membrane protein family, PERP was originally identified as a p53 target specifically trans-activated during apoptosis, but not during cell-cycle arrest. Several studies have since shown downregulation of PERP expression in numerous cancers, suggesting that PERP is a tumour suppressor protein. This review focusses on the important advances made in elucidating the mechanisms regulating PERP expression and its function as a tumour suppressor in diverse human cancers, including breast cancer and squamous cell carcinoma. Investigating PERP's role in clinically-aggressive uveal melanoma has revealed that PERP engages a positive-feedback loop with p53 to regulate its own expression, and that p63 is required beside p53 to achieve pro-apoptotic levels of PERP in this cancer. Furthermore, the recent discovery of the apoptosis-mediating interaction of PERP with SERCA2b at the plasma membrane-endoplasmic reticulum interface demonstrates a novel mechanism of PERP stabilisation, and how PERP can mediate Ca2+ signalling to facilitate apoptosis. The multi-faceted role of PERP in cancer, involving well-documented functions in mediating apoptosis and cell-cell adhesion is discussed, alongside PERP's emerging roles in epithelial-mesenchymal transition, and PERP crosstalk with inflammation signalling pathways, and other signalling pathways. The potential for restoring PERP expression as a means of cancer therapy is also considered.
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Affiliation(s)
- Owain Roberts
- Department of Eye and Vision Science, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Luminita Paraoan
- Department of Eye and Vision Science, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, United Kingdom.
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Lee S, Bazick H, Chittoor-Vinod V, Al Salihi MO, Xia G, Notterpek L. Elevated Peripheral Myelin Protein 22, Reduced Mitotic Potential, and Proteasome Impairment in Dermal Fibroblasts from Charcot-Marie-Tooth Disease Type 1A Patients. THE AMERICAN JOURNAL OF PATHOLOGY 2017; 188:728-738. [PMID: 29246495 PMCID: PMC5842032 DOI: 10.1016/j.ajpath.2017.10.021] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/06/2017] [Revised: 10/05/2017] [Accepted: 10/27/2017] [Indexed: 12/31/2022]
Abstract
A common form of hereditary autosomal dominant demyelinating neuropathy known as Charcot-Marie-Tooth disease type 1A (CMT1A) is linked with duplication of the peripheral myelin protein 22 (PMP22) gene. Although studies from animal models have led to better understanding of the pathobiology of these neuropathies, there continues to be a gap in the translation of findings from rodents to humans. Because PMP22 was originally identified in fibroblasts as growth arrest specific gene 3 (gas3) and is expressed broadly in the body, it was tested whether skin cells from neuropathic patients would display the cellular pathology observed in Schwann cells from rodent models. Dermal fibroblasts from two CMT1A pedigrees with confirmed PMP22 gene duplication were studied. Samples from age-matched non-neuropathic individuals were used as controls. CMT1A patient–derived cultures contain approximately 1.5-fold elevated levels of PMP22 mRNA, exhibit reduced mitotic potential, and display intracellular protein aggregates as compared to cells from unaffected individuals. The presence of cytosolic PMP22 coincides with a decrease in proteasome activity and an increase in autophagy-lysosomal proteins, including LC3-II and LAMP1. These results indicate that the abnormalities in the subcellular processing of excess PMP22 elicit a detectable response in human CMT1A fibroblasts, a phenotype that resembles Schwann cells from neuropathic mice. These findings support the use of human CMT1A fibroblasts as a platform for therapy testing.
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Affiliation(s)
- Sooyeon Lee
- Department of Neuroscience, College of Medicine, University of Florida, Gainesville, Florida
| | - Hannah Bazick
- Department of Neuroscience, College of Medicine, University of Florida, Gainesville, Florida
| | - Vinita Chittoor-Vinod
- Department of Neuroscience, College of Medicine, University of Florida, Gainesville, Florida
| | - Mohammed Omar Al Salihi
- Department of Neuroscience, College of Medicine, University of Florida, Gainesville, Florida
| | - Guangbin Xia
- Department of Neuroscience, College of Medicine, University of Florida, Gainesville, Florida; Department of Neurology, College of Medicine, University of Florida, Gainesville, Florida
| | - Lucia Notterpek
- Department of Neuroscience, College of Medicine, University of Florida, Gainesville, Florida; Department of Neurology, College of Medicine, University of Florida, Gainesville, Florida.
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Li X, Jiang H, Xiao L, Wang S, Zheng J. miR-200bc/429 Inhibits Osteosarcoma Cell Proliferation and Invasion by Targeting PMP22. Med Sci Monit 2017; 23:1001-1008. [PMID: 28234890 PMCID: PMC5338570 DOI: 10.12659/msm.900084] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Background MicroRNAs (miRNAs) are small non-coding RNAs which play a crucial role in diverse biological processes and could contribute to cancer development and progression. MiR-200bc/429 have been found to be aberrantly expressed in osteosarcoma (OS). However, the features of miR-200bc/429 in the tumorigenesis and progress of OS remain poorly understood. Material/Methods The miR-200bc/429 expression was firstly identified in human OS clinical samples and cell lines by quantitative real-time PCR (qRT-PCR). After transfection with miR-200bc/429 mimics or negative control in U2OS or MG63 cells, cell proliferation was measured by CCK-8 assay. Following that, wound-healing assay and Transwell invasion assay were performed to evaluate cell migration and invasion, respectively. Finally, luciferase reporter assay and Western blot analysis were performed to determine if peripheral myelin protein-22 (PMP22) is a direct target of miR-200bc/429. Results Results revealed that miR-200bc/429 were significantly depressed in human OS tissues and cell lines by qRT-PCR. Then, restoration of miR-200bc/429 significantly inhibited cell proliferation (P<0.05) and invasion (P<0.05) in vitro. Luciferase reporter assay and Western blot analysis revealed that miR-200bc/429 could directly target PMP22 3′ untranslated region (UTR) and inhibit its expression in U2OS and MG63 cells. Conclusions These findings suggest that miR-200bc/429 inhibit OS cells proliferation and invasion by targeting PMP22, and function as a tumor suppressor and may be a patent molecular marker as well as a potential target for OS therapy.
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Affiliation(s)
- Xiaodong Li
- Department of Orthopedics, Tianjin third central hospital, Tianjin, China (mainland)
| | - Han Jiang
- Department of Orthopedics, Tianjin third central hospital, Tianjin, China (mainland)
| | - Lianping Xiao
- Department of Orthopedics, Tianjin third central hospital, Tianjin, China (mainland)
| | - Shusen Wang
- Department of Orthopedics, Tianjin third central hospital, Tianjin, China (mainland)
| | - Jinxin Zheng
- Department of Orthopedics, Tianjin third central hospital, Tianjin, China (mainland)
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Abstract
The GAS3 family of tetraspan proteins has recently been implicated in the progression of cancer. Currently, six members of the GAS3 family have been identified in humans and mice, and while their expressions in disease vary, data suggest that they play a role in epithelial cell structure and function. In this review, we highlight the studies implicating four of the members in disease pathogenesis as well as probe the structural similarities between the family members. Finally, the impact of targeting select members of the family such as PMP22 and EMP2 is discussed.
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Affiliation(s)
- Negin Ashki
- Department of Ophthalmology, Jules Stein Eye Institute, Los Angeles, CA
| | - Lynn Gordon
- Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA
| | - Madhuri Wadehra
- Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA
- Address all correspondence to: Madhuri Wadehra, PhD, Pathology and Lab Medicine, 14-127 Center for Health Sciences, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095; Tel.: 310-825-1590; Fax: 310-825-5674;
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Rosso G, Negreira C, Sotelo JR, Kun A. Myelinating and demyelinating phenotype of Trembler-J mouse (a model of Charcot-Marie-Tooth human disease) analyzed by atomic force microscopy and confocal microscopy. J Mol Recognit 2012; 25:247-55. [PMID: 22528185 DOI: 10.1002/jmr.2176] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The accumulation of misfolded proteins is associated with various neurodegenerative conditions. Mutations in PMP-22 are associated with the human peripheral neuropathy, Charcot-Marie-Tooth Type 1A (CMT1A). PMP-22 is a short-lived 22 kDa glycoprotein, which plays a key role in the maintenance of myelin structure and compaction, highly expressed by Schwann cells. It forms aggregates when the proteasome is inhibited or the protein is mutated. This study reports the application of atomic force microscopy (AFM) as a detector of profound topographical and mechanical changes in Trembler-J mouse (CMT1A animal model). AFM images showed topographical differences in the extracellular matrix and basal lamina organization of Tr-J/+ nerve fibers. The immunocytochemical analysis indicated that PMP-22 protein is associated with type IV collagen (a basal lamina ubiquitous component) in the Tr-J/+ Schwann cell perinuclear region. Changes in mechanical properties of single myelinating Tr-J/+ nerve fibers were investigated, and alterations in cellular stiffness were found. These results might be associated with F-actin cytoskeleton organization in Tr-J/+ nerve fibers. AFM nanoscale imaging focused on topography and mechanical properties of peripheral nerve fibers might provide new insights into the study of peripheral nervous system diseases.
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Affiliation(s)
- Gonzalo Rosso
- Departamento de Proteínas y Ácidos Nucleicos, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay
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Identification of novel candidate oncogenes in chromosome region 17p11.2-p12 in human osteosarcoma. PLoS One 2012; 7:e30907. [PMID: 22292074 PMCID: PMC3266911 DOI: 10.1371/journal.pone.0030907] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2011] [Accepted: 12/29/2011] [Indexed: 11/19/2022] Open
Abstract
Osteosarcoma is the most common primary malignancy of bone. The tumours are characterized by high genomic instability, including the occurrence of multiple regions of amplifications and deletions. Chromosome region 17p11.2–p12 is amplified in about 25% of cases. In previous studies, COPS3 and PMP22 have been identified as candidate oncogenes in this region. Considering the complexity and variation of the amplification profiles for this segment, the involvement of additional causative oncogenes is to be expected. The aim of the present investigation is to identify novel candidate oncogenes in 17p11.2–p12. We selected 26 of in total 85 osteosarcoma samples (31%) with amplification events in 17p11.2–p12, using quantitative PCR for 8 marker genes. These were subjected to high-resolution SNP array analysis and subsequent GISTIC analysis to identify the most significantly amplified regions. Two major amplification peaks were found in the 17p11.2–p12 region. Overexpression as a consequence of gene amplification is a major mechanism for oncogene activation in tumours. Therefore, to identify the causative oncogenes, we next determined expression levels of all genes within the two segments using expression array data that could be generated for 20 of the selected samples. We identified 11 genes that were overexpressed through amplification in at least 50% of cases. Nine of these, c17orf39, RICH2, c17orf45, TOP3A, COPS3, SHMT1, PRPSAP2, PMP22, and RASD1, demonstrated a significant association between copy number and expression level. We conclude that these genes, including COPS3 and PMP22, are candidate oncogenes in 17p11.2–p12 of importance in osteosarcoma tumourigenesis.
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