1
|
Ayanlaja AA, Zhang B, Ji G, Gao Y, Wang J, Kanwore K, Gao D. The reversible effects of glial cell line-derived neurotrophic factor (GDNF) in the human brain. Semin Cancer Biol 2018; 53:212-222. [PMID: 30059726 DOI: 10.1016/j.semcancer.2018.07.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2018] [Revised: 07/10/2018] [Accepted: 07/18/2018] [Indexed: 12/20/2022]
Abstract
Glial cell line-derived neurotrophic factor (GDNF) is a potent survival factor, and a member of the transforming growth factor β (TGF-β) superfamily acting on different neuronal activities. GDNF was originally identified as a neurotrophic factor crucially involved in the survival of dopaminergic neurons of the nigrostriatal pathway and is currently an established therapeutic target in Parkinson's disease. However, GDNF was later reported to be highly expressed in gliomas, especially in glioblastomas, and was demonstrated as a potent proliferation factor involved in the development and migration of gliomas. Here, we review our current understanding and progress made so far by researchers in our laboratories with references to relevant articles to support our discoveries. We present past and recent discoveries on the mechanisms involved in the protection of neurons by GDNF and examine its emerging roles in gliomas, as well as reasons for the abnormal expression in Glioblastoma Multiforme (GBM). Collectively, our work establishes a paradigm by which the ability of GDNF to protect dopaminergic neurons from degradation and its corresponding effects on glioma cells points to an underlying biological vulnerability in the effects of GDNF in the normal brain which can be subverted for use by cancer cells. Hence, presenting novel opportunities for intervention in glioma therapies.
Collapse
Affiliation(s)
- Abiola Abdulrahman Ayanlaja
- Xuzhou Key Laboratory of Neurobiology, Department of Neurobiology and Anatomy, Xuzhou Medical University, Xuzhou 221004, Jiangsu, China
| | - Baole Zhang
- Xuzhou Key Laboratory of Neurobiology, Department of Neurobiology and Anatomy, Xuzhou Medical University, Xuzhou 221004, Jiangsu, China
| | - GuangQuan Ji
- Xuzhou Key Laboratory of Neurobiology, Department of Neurobiology and Anatomy, Xuzhou Medical University, Xuzhou 221004, Jiangsu, China
| | - Yue Gao
- Xuzhou Key Laboratory of Neurobiology, Department of Neurobiology and Anatomy, Xuzhou Medical University, Xuzhou 221004, Jiangsu, China
| | - Jie Wang
- Xuzhou Key Laboratory of Neurobiology, Department of Neurobiology and Anatomy, Xuzhou Medical University, Xuzhou 221004, Jiangsu, China
| | - Kouminin Kanwore
- Xuzhou Key Laboratory of Neurobiology, Department of Neurobiology and Anatomy, Xuzhou Medical University, Xuzhou 221004, Jiangsu, China
| | - DianShuai Gao
- Xuzhou Key Laboratory of Neurobiology, Department of Neurobiology and Anatomy, Xuzhou Medical University, Xuzhou 221004, Jiangsu, China.
| |
Collapse
|
2
|
Czaja AJ. Epigenetic changes and their implications in autoimmune hepatitis. Eur J Clin Invest 2018; 48. [PMID: 29383703 DOI: 10.1111/eci.12899] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 01/25/2018] [Indexed: 12/12/2022]
Abstract
BACKGROUND The genetic risk of autoimmune hepatitis is insufficient to explain the observed risk, and epigenetic changes may explain disparities in disease occurrence in different populations within and between countries. The goal of this review was to examine how epigenetic changes induced by the environment or inherited as a phenotypic trait may affect autoimmune hepatitis and be amenable to therapeutic intervention. MATERIALS AND METHODS Pertinent abstracts were identified in PubMed by multiple search terms. The number of abstracts reviewed was 1689, and the number of full-length articles reviewed exceeded 150. RESULTS Activation of pro-inflammatory genes in autoimmune disease is associated with hypomethylation of deoxyribonucleic acid and modification of histones within chromatin. Organ-specific microribonucleic acids can silence genes by marking messenger ribonucleic acids for degradation, and they can promote inflammatory activity or immunosuppression. High circulating levels of the microribonucleic acids 21 and 122 have been demonstrated in autoimmune hepatitis, and they may increase production of pro-inflammatory cytokines. Microribonucleic acids are also essential for maintaining regulatory T cells. Drugs, pollutants, infections, diet and ageing can induce inheritable epigenetic changes favouring autoimmunity. Reversal is feasible by manipulating enzymes, transcription factors, gene-silencing molecules and toxic exposures or by administering methyl donors and correcting vitamin D deficiency. Gene targets, site specificity, efficacy and consequences are uncertain. CONCLUSIONS Potentially reversible epigenetic changes may affect the occurrence and outcome of autoimmune hepatitis, and investigations are warranted to determine the nature of these changes, key genomic targets, and feasible interventions and their consequences.
Collapse
Affiliation(s)
- Albert J Czaja
- Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine and Science, Rochester, MN, USA
| |
Collapse
|
3
|
Park JL, Lee YS, Kunkeaw N, Kim SY, Kim IH, Lee YS. Epigenetic regulation of noncoding RNA transcription by mammalian RNA polymerase III. Epigenomics 2017; 9:171-187. [PMID: 28112569 DOI: 10.2217/epi-2016-0108] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
RNA polymerase III (Pol III) synthesizes a range of medium-sized noncoding RNAs (collectively 'Pol III genes') whose early established biological roles were so essential that they were considered 'housekeeping genes'. Besides these fundamental functions, diverse unconventional roles of mammalian Pol III genes have recently been recognized and their expression must be exquisitely controlled. In this review, we summarize the epigenetic regulation of Pol III genes by chromatin structure, histone modification and CpG DNA methylation. We also recapitulate the association between dysregulation of Pol III genes and diseases such as cancer and neurological disorders. Additionally, we will discuss why in-depth molecular studies of Pol III genes have not been attempted and how nc886, a Pol III gene, may resolve this issue.
Collapse
Affiliation(s)
- Jong-Lyul Park
- Personalized Genomic Medicine Research Center, KRIBB, Daejeon 305-806, Korea.,Department of Functional Genomics, University of Science & Technology, Daejeon 305-806, Korea
| | - Yeon-Su Lee
- Cancer Genomics Branch, Research Institute, National Cancer Center, Goyang 10408, Korea
| | - Nawapol Kunkeaw
- Department of Biochemistry & Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555-1072, USA.,Institute of Molecular Biosciences, Mahidol University, Nakhon Pathom, 73170, Thailand
| | - Seon-Young Kim
- Personalized Genomic Medicine Research Center, KRIBB, Daejeon 305-806, Korea.,Department of Functional Genomics, University of Science & Technology, Daejeon 305-806, Korea
| | - In-Hoo Kim
- Graduate School of Cancer Science & Policy, National Cancer Center, Goyang 10408, Korea
| | - Yong Sun Lee
- Department of Biochemistry & Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555-1072, USA.,Graduate School of Cancer Science & Policy, National Cancer Center, Goyang 10408, Korea
| |
Collapse
|
4
|
Park JL, Lee YS, Song MJ, Hong SH, Ahn JH, Seo EH, Shin SP, Lee SJ, Johnson BH, Stampfer MR, Kim HP, Kim SY, Lee YS. Epigenetic regulation of RNA polymerase III transcription in early breast tumorigenesis. Oncogene 2017; 36:6793-6804. [PMID: 28846112 DOI: 10.1038/onc.2017.285] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2017] [Revised: 06/13/2017] [Accepted: 07/03/2017] [Indexed: 02/07/2023]
Abstract
RNA polymerase III (Pol III) transcribes medium-sized non-coding RNAs (collectively termed Pol III genes). Emerging diverse roles of Pol III genes suggest that individual Pol III genes are exquisitely regulated by transcription and epigenetic factors. Here we report global Pol III expression/methylation profiles and molecular mechanisms of Pol III regulation that have not been as extensively studied, using nc886 as a representative Pol III gene. In a human mammary epithelial cell system that recapitulates early breast tumorigenesis, the fraction of actively transcribed Pol III genes increases reaching a plateau during immortalization. Hyper-methylation of Pol III genes inhibits Pol III binding to DNA via inducing repressed chromatin and is a determinant for the Pol III repertoire. When Pol III genes are hypo-methylated, MYC amplifies their transcription, regardless of its recognition DNA motif. Thus, Pol III expression during tumorigenesis is delineated by methylation and magnified by MYC.
Collapse
Affiliation(s)
- J-L Park
- Personalized Genomic Medicine Research Center, KRIBB, Daejeon, Korea.,Department of Functional Genomics, University of Science and Technology, Daejeon, Korea
| | - Y-S Lee
- Rare Cancer Branch, Research Institute, National Cancer Center, Goyang-si, Korea
| | - M-J Song
- Department of Environmental Medical Biology, Yonsei University College of Medicine, Seoul, Korea
| | - S-H Hong
- Rare Cancer Branch, Research Institute, National Cancer Center, Goyang-si, Korea
| | - J-H Ahn
- Department of Life and Nanopharmaceutical Sciences and Department of Oriental Pharmacy, Kyung Hee University, Seoul, Korea
| | - E-H Seo
- Personalized Genomic Medicine Research Center, KRIBB, Daejeon, Korea.,Department of Functional Genomics, University of Science and Technology, Daejeon, Korea
| | - S-P Shin
- Immunotherapeutics Branch, Research Institute, National Cancer Center, Goyang-si, Korea
| | - S-J Lee
- Immunotherapeutics Branch, Research Institute, National Cancer Center, Goyang-si, Korea
| | - B H Johnson
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, USA
| | - M R Stampfer
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - H-P Kim
- Department of Environmental Medical Biology, Yonsei University College of Medicine, Seoul, Korea.,Institute of Tropical Medicine, Yonsei University College of Medicine, Seoul, Korea.,Brain Korea 21 Plus Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea
| | - S-Y Kim
- Personalized Genomic Medicine Research Center, KRIBB, Daejeon, Korea.,Department of Functional Genomics, University of Science and Technology, Daejeon, Korea
| | - Y S Lee
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, USA.,Department of Cancer Biomedical Science, Graduate School of Cancer Science and Policy, National Cancer Center, Goyang, Korea
| |
Collapse
|
5
|
Epigenetic Alterations in Epstein-Barr Virus-Associated Diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 879:39-69. [DOI: 10.1007/978-3-319-24738-0_3] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
|
6
|
Lee KS, Park JL, Lee K, Richardson LE, Johnson BH, Lee HS, Lee JS, Kim SB, Kwon OH, Song KS, Kim YS, Ashktorab H, Smoot DT, Jeon SH, Kim SY, Lee YS. nc886, a non-coding RNA of anti-proliferative role, is suppressed by CpG DNA methylation in human gastric cancer. Oncotarget 2014; 5:3944-55. [PMID: 25003254 PMCID: PMC4116533 DOI: 10.18632/oncotarget.2047] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Accepted: 05/30/2014] [Indexed: 02/07/2023] Open
Abstract
nc886 is a 101 nucleotide long non-coding RNA that has been designated as a precursor microRNA or a vault RNA based upon it sequence. nc886 has also been suggested to be a tumor suppressor, mainly inferred by its expression pattern as well as its genomic location at human chromosome 5q31, a locus for a tumor suppressor gene(s). However, legitimate data based on nc886's correct identity for its functional cellular roles as a tumor suppressor have not been provided yet. Here we have investigated nc886 in gastric cancer where its expression is suppressed due to CpG DNA hypermethylation at its promoter region in a cohort of paired tumor/normal tissues from 88 gastric cancer patients. CpG hypermethylation of nc886 and thus its diminished expression is significantly associated with poor survival in these cancer patients. nc886 inhibits cell proliferation when ectopically expressed in gastric cancer cells. nc886's tumor suppressive role is corroborated by the induction of well-known oncogenes such as FOS, NF-κB, and MYC upon its knockdown. All these activities of nc886 are undoubtedly independent of mature microRNA or vault RNA. Our data indicate that nc886 is a putative tumor suppressor and could potentially be used as a diagnostic marker in gastric cancer.
Collapse
Affiliation(s)
- Kwang-Soo Lee
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, TX, USA
- Department of Life Science and Center for Aging and Health Care, Hallym University, Chuncheon, Korea
- co-first authors
| | - Jong-Lyul Park
- Medical Genomics Research Center, KRIBB, Daejeon, Korea
- Department of Functional Genomics, University of Science and Technology, Daejeon, Korea
- co-first authors
| | - Kwanbok Lee
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, TX, USA
| | - Lauren E. Richardson
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, TX, USA
- Lamar University, Beaumont, TX77710, USA
| | - Betty H. Johnson
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, TX, USA
| | - Hyun-Sung Lee
- Department of Systems Biology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Ju-Seog Lee
- Department of Systems Biology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Sang-Bae Kim
- Department of Systems Biology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Oh-Hyung Kwon
- Medical Genomics Research Center, KRIBB, Daejeon, Korea
| | - Kyu Sang Song
- Department of Pathology, College of Medicine, Chungnam National University, Daejeon, Korea
| | - Yong Sung Kim
- Medical Genomics Research Center, KRIBB, Daejeon, Korea
- Department of Functional Genomics, University of Science and Technology, Daejeon, Korea
| | - Hassan Ashktorab
- Departments of Medicine, Howard University, Washington, D. C., USA
| | - Duane T. Smoot
- Departments of Medicine, Howard University, Washington, D. C., USA
| | - Sung Ho Jeon
- Department of Life Science and Center for Aging and Health Care, Hallym University, Chuncheon, Korea
| | - Seon-Young Kim
- Medical Genomics Research Center, KRIBB, Daejeon, Korea
- Department of Functional Genomics, University of Science and Technology, Daejeon, Korea
| | - Yong Sun Lee
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, TX, USA
| |
Collapse
|
7
|
Yu ZQ, Zhang BL, Ren QX, Wang JC, Yu RT, Qu DW, Liu ZH, Xiong Y, Gao DS. Changes in Transcriptional Factor Binding Capacity Resulting from Promoter Region Methylation Induce Aberrantly High GDNF Expression in Human Glioma. Mol Neurobiol 2013; 48:571-80. [DOI: 10.1007/s12035-013-8443-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Accepted: 03/13/2013] [Indexed: 01/20/2023]
|
8
|
Selvakumar T, Gjidoda A, Hovde SL, Henry RW. Regulation of human RNA polymerase III transcription by DNMT1 and DNMT3a DNA methyltransferases. J Biol Chem 2012; 287:7039-50. [PMID: 22219193 DOI: 10.1074/jbc.m111.285601] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The human small nuclear RNA (snRNA) and small cytoplasmic RNA (scRNA) gene families encode diverse non-coding RNAs that influence cellular growth and division. Many snRNA and scRNA genes are related via their compact and yet powerful promoters that support RNA polymerase III transcription. We have utilized the human U6 snRNA gene family to examine the mechanism for regulated transcription of these potent transcription units. Analysis of nine U6 family members showed enriched CpG density within the promoters of actively transcribed loci relative to inert genes, implying a relationship between gene potency and DNA methylation. Indeed, both pharmacological inhibition of DNA methyltransferase (DNMT) activity and the forced diminution of DNMT-1, DNMT-3a, and DNMT-3b by siRNA targeting resulted in increased U6 levels in asynchronously growing MCF7 adenocarcinoma cells. In vitro transcription assays further showed that template methylation impedes U6 transcription by RNA polymerase III. Both DNMT-1 and DNMT-3a were detected at the U6-1 locus by chromatin immunoprecipitation directly linking these factors to RNA polymerase III regulation. Despite this association, the endogenous U6-1 locus was not substantially methylated in actively growing cells. However, both DNMT occupancy and low frequency methylation were correlated with increased Retinoblastoma tumor suppressor (RB) expression, suggesting that the RB status can influence specific epigenetic marks.
Collapse
Affiliation(s)
- Tharakeswari Selvakumar
- Cell and Molecular Biology Program, Michigan State University, East Lansing, Michigan 48824, USA
| | | | | | | |
Collapse
|
9
|
Tang W, Harmon P, Gulley ML, Mwansambo C, Kazembe PN, Martinson F, Wokocha C, Kenney SC, Hoffman I, Sigel C, Maygarden S, Hoffman M, Shores C. Viral response to chemotherapy in endemic burkitt lymphoma. Clin Cancer Res 2010; 16:2055-64. [PMID: 20233888 DOI: 10.1158/1078-0432.ccr-09-2424] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
PURPOSE Some EBV-directed therapies are predicted to be effective only when lytic viral replication occurs. We studied whether cyclophosphamide chemotherapy induces EBV to switch from latent to lytic phases of infection in a series of EBV-associated Burkitt lymphomas. EXPERIMENTAL DESIGN Children with first presentation of an expanding, solid maxillary or mandibular mass consistent with Burkitt lymphoma underwent fine-needle aspiration just prior to the initiation of cyclophosphamide therapy and again 1 to 5 days later. Aspirated cells were examined for latent and lytic EBV infection using in situ hybridization to EBV-encoded RNA (EBER), immunohistochemical analysis of the lytic EBV proteins BZLF1 and BMRF1, reverse transcription PCR targeting BZLF1 transcripts, and EBV viral load measurement by quantitative PCR. RESULTS Among 21 lymphomas expressing EBER prior to chemotherapy, 9 of 10 still expressed EBER on day 1 after therapy whereas only 2 of 11 (18%) specimens still expressed EBER at days 3 to 5, implying that chemotherapy was fairly effective at eliminating latently infected cells. Neither of the lytic products, BZLF1 or BMRF1, were significantly upregulated at the posttherapy time points examined. However, EBV genomic copy number increased in 5 of 10 samples 1 day after treatment began, suggesting that viral replication occurs within the first 24 hours. CONCLUSION Cyclophosphamide may induce the lytic phase of EBV infection and is fairly effective in diminishing EBER-expressing tumor cells within 5 days. These findings provide the rationale for a trial testing synergistic tumor cell killing using cyclophosphamide with a drug like ganciclovir targeting lytically infected cells.
Collapse
Affiliation(s)
- Weihua Tang
- Departments of Pathology and Laboratory Medicine, Otolaryngology/Head and Neck Surgery, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7525, USA
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Takacs M, Segesdi J, Banati F, Koroknai A, Wolf H, Niller HH, Minarovits J. The importance of epigenetic alterations in the development of epstein-barr virus-related lymphomas. Mediterr J Hematol Infect Dis 2009; 1:e2009012. [PMID: 21416002 PMCID: PMC3033174 DOI: 10.4084/mjhid.2009.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2009] [Accepted: 11/13/2009] [Indexed: 12/13/2022] Open
Abstract
Epstein-Barr virus (EBV), a human gammaherpesvirus, is associated with a series of malignant tumors. These include lymphomas (Burkitt's lymphoma, Hodgkin's disease, T/NK-cell lymphoma, post-transplant lymphoproliferative disease, AIDS-associated lymphoma, X-linked lymphoproliferative syndrome), carcinomas (nasopharyngeal carcinoma, gastric carcinoma, carcinomas of major salivary glands, thymic carcinoma, mammary carcinoma) and a sarcoma (leiomyosarcoma). The latent EBV genomes persist in the tumor cells as circular episomes, co-replicating with the cellular DNA once per cell cycle. The expression of latent EBV genes is cell type specific due to the strict epigenetic control of their promoters. DNA methylation, histone modifications and binding of key cellular regulatory proteins contribute to the regulation of alternative promoters for transcripts encoding the nuclear antigens EBNA1 to 6 and affect the activity of promoters for transcripts encoding transmembrane proteins (LMP1, LMP2A, LMP2B). In addition to genes transcribed by RNA polymerase II, there are also two RNA polymerase III transcribed genes in the EBV genome (EBER 1 and 2). The 5' and internal regulatory sequences of EBER 1 and 2 transcription units are invariably unmethylated. The highly abundant EBER 1 and 2 RNAs are not translated to protein. Based on the cell type specific epigenetic marks associated with latent EBV genomes one can distinguish between viral epigenotypes that differ in transcriptional activity in spite of having an identical (or nearly identical) DNA sequence. Whereas latent EBV genomes are regularly targeted by epigenetic control mechanisms in different cell types, EBV encoded proteins may, in turn, affect the activity of a set of cellular promoters by interacting with the very same epigenetic regulatory machinery. There are EBNA1 binding sites in the human genome. Because high affinity binding of EBNA1 to its recognition sites is known to specify sites of DNA demethylation, we suggest that binding of EBNA1 to its cellular target sites may elicit local demethylation and contribute thereby to the activation of silent cellular promoters. EBNA2 interacts with histone acetyltransferases, and EBNALP (EBNA5) coactivates transcription by displacing histone deacetylase 4 from EBNA2-bound promoter sites. EBNA3C (EBNA6) seems to be associated both with histone acetylases and deacetylases, although in separate complexes. LMP1, a transmembrane protein involved in malignant transformation, can affect both alternative systems of epigenetic memory, DNA methylation and the Polycomb-trithorax group of protein complexes. In epithelial cells LMP1 can up-regulate DNA methyltransferases and, in Hodgkin lymphoma cells, induce the Polycomb group protein Bmi-1. In addition, LMP1 can also modulate cellular gene expression programs by affecting, via the NF-κB pathway, levels of cellular microRNAs miR-146a and miR-155. These interactions may result in epigenetic dysregulation and subsequent cellular dysfunctions that may manifest in or contribute to the development of pathological changes (e.g. initiation and progression of malignant neoplasms, autoimmune phenomena, immunodeficiency). Thus, Epstein-Barr virus, similarly to other viruses and certain bacteria, may induce pathological changes by epigenetic reprogramming of host cells. Elucidation of the epigenetic consequences of EBV-host interactions (within the framework of the emerging new field of patho-epigenetics) may have important implications for therapy and disease prevention, because epigenetic processes are reversible and continuous silencing of EBV genes contributing to patho-epigenetic changes may prevent disease development.
Collapse
Affiliation(s)
- Maria Takacs
- Division of Virology, National Center for Epidemiology, H-1097 Budapest, Gyali út 2-6, Hungary
| | - Judit Segesdi
- Microbiological Research Group, National Center for Epidemiology, H-1529 Budapest, Pihenö u. 1. Hungary
| | - Ferenc Banati
- Microbiological Research Group, National Center for Epidemiology, H-1529 Budapest, Pihenö u. 1. Hungary
| | - Anita Koroknai
- Microbiological Research Group, National Center for Epidemiology, H-1529 Budapest, Pihenö u. 1. Hungary
| | - Hans Wolf
- Institute for Medical Microbiology and Hygiene, University of Regensburg, Franz-Josef-Strauss-Allee 11, D-93053 Regensburg, Germany
| | - Hans Helmut Niller
- Institute for Medical Microbiology and Hygiene, University of Regensburg, Franz-Josef-Strauss-Allee 11, D-93053 Regensburg, Germany
| | - Janos Minarovits
- Microbiological Research Group, National Center for Epidemiology, H-1529 Budapest, Pihenö u. 1. Hungary
| |
Collapse
|
11
|
Binding of CCCTC-binding factor in vivo to the region located between Rep* and the C promoter of Epstein–Barr virus is unaffected by CpG methylation and does not correlate with Cp activity. J Gen Virol 2009; 90:1183-1189. [DOI: 10.1099/vir.0.007344-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In this study, the binding of the insulator protein CCCTC-binding factor (CTCF) to the region located between Rep* and the C promoter (Cp) of Epstein–Barr virus (EBV) was analysed using chromatin immunoprecipitation and in vivo footprinting. CTCF binding was found to be independent of Cp usage in cell lines corresponding to the major EBV latency types. Bisulfite sequencing and an electrophoretic mobility-shift assay (using methylated and unmethylated probes) revealed that CTCF binding was insufficient to induce local CpG demethylation in certain cell lines and was unaffected by CpG methylation in the region between Rep* and Cp. In addition, CTCF binding to the latency promoter, Qp, did not correlate with Qp activity.
Collapse
|