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Martella C, Waast L, Pique C. [Tax, the puppet master of HTLV-1 transcription]. Med Sci (Paris) 2022; 38:359-365. [PMID: 35485896 DOI: 10.1051/medsci/2022039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Retroviruses exploit the RNA polymerase II transcription machinery for the transcription of their genes. This is the case of Human T-lymphotropic virus type 1 (HTLV-1), the retrovirus responsible for adult T-cell leukemia and for various inflammatory diseases. HTLV-1 transcription is under the control of the viral protein Tax, which exhibits an original mode of action since it does not rely on direct promoter interaction but rather on the recruitment of various cellular factors and cofactors of transcription. The factors that Tax recruits are involved in the initial step of promoter activation but also in the subsequent steps of the transcription process itself. This review describes this particular mechanism of viral transcription, from the epigenetic release of the viral promoter to the elongation of the neosynthesized viral silencing transcripts.
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Affiliation(s)
- Christophe Martella
- Équipe Rétrovirus, infection et latence, Université Paris Cité, Inserm U1016, CNRS UMR8104, Institut Cochin, 22 rue Méchain, 75014 Paris, France
| | - Laetitia Waast
- Équipe Rétrovirus, infection et latence, Université Paris Cité, Inserm U1016, CNRS UMR8104, Institut Cochin, 22 rue Méchain, 75014 Paris, France
| | - Claudine Pique
- Équipe Rétrovirus, infection et latence, Université Paris Cité, Inserm U1016, CNRS UMR8104, Institut Cochin, 22 rue Méchain, 75014 Paris, France
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Targeting HNRNPM Inhibits Cancer Stemness and Enhances Antitumor Immunity in Wnt-activated Hepatocellular Carcinoma. Cell Mol Gastroenterol Hepatol 2022; 13:1413-1447. [PMID: 35158098 PMCID: PMC8938476 DOI: 10.1016/j.jcmgh.2022.02.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Revised: 02/04/2022] [Accepted: 02/04/2022] [Indexed: 01/10/2023]
Abstract
BACKGROUND & AIMS Cancer stemness and immune evasion are closely associated and play critical roles in tumor development and resistance to immunotherapy. However, little is known about the underlying molecular mechanisms that coordinate this association. METHODS The expressions of heterogeneous nuclear ribonucleoprotein M (HNRNPM) in 240 hepatocellular carcinoma (HCC) samples, public databases, and liver development databases were analyzed. Chromatin immunoprecipitation assays were performed to explore the associations between stem-cell transcription factors and HNRNPM. HNRNPM-regulated alternative splicing (AS) and its binding motif were identified by RNA-seq and RIP-seq. HNRNPM-specific antisense oligonucleotides were developed to explore potential therapeutic targets in HCC. CD8+ T cells that were co-cultured with tumor cells were sorted by flow cytometry assays. RESULTS We identified an elevated oncofetal splicing factor in HCC, HNRNPM, that unifies and regulates the positive association between cancer stemness and immune evasion. HNRNPM knockdown abolished HCC tumorigenesis and diminished cancer stem cell properties in vitro and in vivo. Mechanistically, HNRNPM regulated the AS of MBD2 by binding its flanking introns, whose isoforms played opposing roles. Although MBD2a and MBD2c competitively bound to CpG islands in the FZD3 promoter, MBD2a preferentially increased FZD3 expression and then activated the WNT/β-catenin pathway. Interestingly, FZD3 and β-catenin further provided additional regulation by targeting OCT4 and SOX2. We found that HNRNPM inhibition significantly promoted CD8+ T cell activation and that HNRNPM- antisense oligonucleotides effectively inhibited WNT/β-catenin to enhance anti-programmed cell death protein-1 immunotherapy by promoting CD8+ T cell infiltration. CONCLUSIONS HNRNPM has a tumor-intrinsic function in generating an immunosuppressive HCC environment through an AS-dependent mechanism and demonstrates proof of the concept of targeting HNRNPM in tailoring HCC immunotherapeutic approaches.
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Pietropaolo V, Prezioso C, Moens U. Role of Virus-Induced Host Cell Epigenetic Changes in Cancer. Int J Mol Sci 2021; 22:ijms22158346. [PMID: 34361112 PMCID: PMC8346956 DOI: 10.3390/ijms22158346] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 07/30/2021] [Accepted: 08/02/2021] [Indexed: 12/12/2022] Open
Abstract
The tumor viruses human T-lymphotropic virus 1 (HTLV-1), hepatitis C virus (HCV), Merkel cell polyomavirus (MCPyV), high-risk human papillomaviruses (HR-HPVs), Epstein-Barr virus (EBV), Kaposi’s sarcoma-associated herpes virus (KSHV) and hepatitis B virus (HBV) account for approximately 15% of all human cancers. Although the oncoproteins of these tumor viruses display no sequence similarity to one another, they use the same mechanisms to convey cancer hallmarks on the infected cell. Perturbed gene expression is one of the underlying mechanisms to induce cancer hallmarks. Epigenetic processes, including DNA methylation, histone modification and chromatin remodeling, microRNA, long noncoding RNA, and circular RNA affect gene expression without introducing changes in the DNA sequence. Increasing evidence demonstrates that oncoviruses cause epigenetic modifications, which play a pivotal role in carcinogenesis. In this review, recent advances in the role of host cell epigenetic changes in virus-induced cancers are summarized.
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Affiliation(s)
- Valeria Pietropaolo
- Department of Public Health and Infectious Diseases, “Sapienza” University, 00185 Rome, Italy;
- Correspondence: (V.P.); (U.M.)
| | - Carla Prezioso
- Department of Public Health and Infectious Diseases, “Sapienza” University, 00185 Rome, Italy;
- IRCSS San Raffaele Roma, Microbiology of Chronic Neuro-Degenerative Pathologies, 00161 Rome, Italy
| | - Ugo Moens
- Molecular Inflammation Research Group, Department of Medical Biology, Faculty of Health Sciences, University of Tromsø—The Arctic University of Norway, 9037 Tromsø, Norway
- Correspondence: (V.P.); (U.M.)
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Liu Z, Sun L, Cai Y, Shen S, Zhang T, Wang N, Wu G, Ma W, Li ST, Suo C, Hao Y, Jia WD, Semenza GL, Gao P, Zhang H. Hypoxia-Induced Suppression of Alternative Splicing of MBD2 Promotes Breast Cancer Metastasis via Activation of FZD1. Cancer Res 2021; 81:1265-1278. [PMID: 33402389 DOI: 10.1158/0008-5472.can-20-2876] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 11/19/2020] [Accepted: 12/29/2020] [Indexed: 11/16/2022]
Abstract
Metastasis is responsible for the majority of breast cancer-related deaths, however, the mechanisms underlying metastasis in this disease remain largely elusive. Here we report that under hypoxic conditions, alternative splicing of MBD2 is suppressed, favoring the production of MBD2a, which facilitates breast cancer metastasis. Specifically, MBD2a promoted, whereas its lesser known short form MBD2c suppressed metastasis. Activation of HIF1 under hypoxia facilitated MBD2a production via repression of SRSF2-mediated alternative splicing. As a result, elevated MBD2a outcompeted MBD2c for binding to promoter CpG islands to activate expression of FZD1, thereby promoting epithelial-to-mesenchymal transition and metastasis. Strikingly, clinical data reveal significantly correlated expression of MBD2a and MBD2c with the invasiveness of malignancy, indicating opposing roles for MBD2 splicing variants in regulating human breast cancer metastasis. Collectively, our findings establish a novel link between MBD2 switching and tumor metastasis and provide a promising therapeutic strategy and predictive biomarkers for hypoxia-driven breast cancer metastasis. SIGNIFICANCE: This study defines the opposing roles and clinical relevance of MBD2a and MBD2c, two MBD2 alternative splicing products, in hypoxia-driven breast cancer metastasis. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/81/5/1265/F1.large.jpg.
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Affiliation(s)
- Zhaoji Liu
- Department of General Surgery, Anhui Provincial Hospital, The First Affiliated Hospital of USTC, University of Science and Technology of China, Hefei, China
- Hefei National Laboratory for Physical Sciences at Microscale, The CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Life Sciences and Medical Center, University of Science and Technology of China, Hefei, China
| | - Linchong Sun
- Department of General Surgery, Anhui Provincial Hospital, The First Affiliated Hospital of USTC, University of Science and Technology of China, Hefei, China
- Laboratory of Cancer and Stem Cell Metabolism, School of Medicine, Institutes for Life Sciences, South China University of Technology, Guangzhou, China
| | - Yongping Cai
- Department of Pathology, School of Medicine, Anhui Medical University, Hefei, China
| | - Shengqi Shen
- Department of General Surgery, Anhui Provincial Hospital, The First Affiliated Hospital of USTC, University of Science and Technology of China, Hefei, China
- Hefei National Laboratory for Physical Sciences at Microscale, The CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Life Sciences and Medical Center, University of Science and Technology of China, Hefei, China
| | - Tong Zhang
- Department of General Surgery, Anhui Provincial Hospital, The First Affiliated Hospital of USTC, University of Science and Technology of China, Hefei, China
- Hefei National Laboratory for Physical Sciences at Microscale, The CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Life Sciences and Medical Center, University of Science and Technology of China, Hefei, China
| | - Nana Wang
- Department of Pathology, School of Medicine, Anhui Medical University, Hefei, China
| | - Gongwei Wu
- Department of General Surgery, Anhui Provincial Hospital, The First Affiliated Hospital of USTC, University of Science and Technology of China, Hefei, China
| | - Wenhao Ma
- Department of General Surgery, Anhui Provincial Hospital, The First Affiliated Hospital of USTC, University of Science and Technology of China, Hefei, China
| | - Shi-Ting Li
- Department of General Surgery, Anhui Provincial Hospital, The First Affiliated Hospital of USTC, University of Science and Technology of China, Hefei, China
| | - Caixia Suo
- Laboratory of Cancer and Stem Cell Metabolism, School of Medicine, Institutes for Life Sciences, South China University of Technology, Guangzhou, China
| | - Yijie Hao
- Department of General Surgery, Anhui Provincial Hospital, The First Affiliated Hospital of USTC, University of Science and Technology of China, Hefei, China
| | - Wei-Dong Jia
- Department of General Surgery, Anhui Provincial Hospital, The First Affiliated Hospital of USTC, University of Science and Technology of China, Hefei, China
| | - Gregg L Semenza
- School of Medicine, Johns Hopkins University, Baltimore, Maryland
| | - Ping Gao
- Hefei National Laboratory for Physical Sciences at Microscale, The CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Life Sciences and Medical Center, University of Science and Technology of China, Hefei, China.
- Laboratory of Cancer and Stem Cell Metabolism, School of Medicine, Institutes for Life Sciences, South China University of Technology, Guangzhou, China
- Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, China
| | - Huafeng Zhang
- Department of General Surgery, Anhui Provincial Hospital, The First Affiliated Hospital of USTC, University of Science and Technology of China, Hefei, China.
- Hefei National Laboratory for Physical Sciences at Microscale, The CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Life Sciences and Medical Center, University of Science and Technology of China, Hefei, China
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Acetylation- and Methylation-Related Epigenetic Proteins in the Context of Their Targets. Genes (Basel) 2017; 8:genes8080196. [PMID: 28783137 PMCID: PMC5575660 DOI: 10.3390/genes8080196] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 07/19/2017] [Accepted: 07/31/2017] [Indexed: 12/19/2022] Open
Abstract
The nucleosome surface is covered with multiple modifications that are perpetuated by eight different classes of enzymes. These enzymes modify specific target sites both on DNA and histone proteins, and these modifications have been well identified and termed “epigenetics”. These modifications play critical roles, either by affecting non-histone protein recruitment to chromatin or by disturbing chromatin contacts. Their presence dictates the condensed packaging of DNA and can coordinate the orderly recruitment of various enzyme complexes for DNA manipulation. This genetic modification machinery involves various writers, readers, and erasers that have unique structures, functions, and modes of action. Regarding human disease, studies have mainly focused on the genetic mechanisms; however, alteration in the balance of epigenetic networks can result in major pathologies including mental retardation, chromosome instability syndromes, and various types of cancers. Owing to its critical influence, great potential lies in developing epigenetic therapies. In this regard, this review has highlighted mechanistic and structural interactions of the main epigenetic families with their targets, which will help to identify more efficient and safe drugs against several diseases.
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Claveria-Gimeno R, Abian O, Velazquez-Campoy A, Ausió J. MeCP2… Nature’s Wonder Protein or Medicine’s Most Feared One? CURRENT GENETIC MEDICINE REPORTS 2016. [DOI: 10.1007/s40142-016-0107-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Alvarado S, Wyglinski J, Suderman M, Andrews SA, Szyf M. Methylated DNA binding domain protein 2 (MBD2) coordinately silences gene expression through activation of the microRNA hsa-mir-496 promoter in breast cancer cell line. PLoS One 2013; 8:e74009. [PMID: 24204564 PMCID: PMC3812180 DOI: 10.1371/journal.pone.0074009] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Accepted: 07/25/2013] [Indexed: 12/31/2022] Open
Abstract
Methylated DNA binding protein 2 (MBD2) binds methylated promoters and suppresses transcription in cis through recruitment of a chromatin modification repressor complex. We show here a new mechanism of action for MBD2: suppression of gene expression indirectly through activation of microRNA hsa-mir-496. Overexpression of MBD2 in breast epithelial cell line MCF-10A results in induced expression and demethylation of hsa-mir-496 while depletion of MBD2 in a human breast cancer cell lines MCF-7 and MDA-MB231 results in suppression of hsa-mir-496. Activation of hsa-mir-496 by MBD2 is associated with silencing of several of its target genes while depletion of MBD2 leads to induction of hsa-mir-496 target genes. Depletion of hsa-mir-496 by locked nucleic acid (LNA) antisense oligonucleotide leads to activation of these target genes in MBD2 overexpressing cells supporting that hsa-mir-496 is mediating in part the effects of MBD2 on gene expression. We demonstrate that MBD2 binds the promoter of hsa-mir-496 in MCF-10A, MCF-7 and MDA-MB-231 cells and that it activates an in vitro methylated hsa-mir-496 promoter driving a CG-less luciferase reporter in a transient transfection assay. The activation of hsa-mir-496 is associated with reduced methylation of the promoter. Taken together these results describe a novel cascade for gene regulation by DNA methylation whereby activation of a methylated microRNA by MBD2 that is associated with loss of methylation triggers repression of downstream targets.
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Affiliation(s)
- Sebastian Alvarado
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada
| | - Joanne Wyglinski
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada
| | - Matthew Suderman
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada
- McGill Centre for Bioinformatics, McGill University, Montreal, Quebec, Canada
| | - Stephen A. Andrews
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada
| | - Moshe Szyf
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada
- Sackler Program for Epigenetics and Developmental Psychobiology, McGill University, Montreal, Quebec, Canada
- * E-mail:
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A role for MeCP2 in switching gene activity via chromatin unfolding and HP1γ displacement. PLoS One 2013; 8:e69347. [PMID: 23935992 PMCID: PMC3720725 DOI: 10.1371/journal.pone.0069347] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Accepted: 06/07/2013] [Indexed: 11/19/2022] Open
Abstract
Methyl-CpG-binding protein 2 (MeCP2) is generally considered to act as a transcriptional repressor, whereas recent studies suggest that MeCP2 is also involved in transcription activation. To gain insight into this dual function of MeCP2, we assessed the impact of MeCP2 on higher-order chromatin structure in living cells using mammalian cell systems harbouring a lactose operator and reporter gene-containing chromosomal domain to assess the effect of lactose repressor-tagged MeCP2 (and separate MeCP2 domains) binding in living cells. Our data reveal that targeted binding of MeCP2 elicits extensive chromatin unfolding. MeCP2-induced chromatin unfolding is triggered independently of the methyl-cytosine-binding domain. Interestingly, MeCP2 binding triggers the loss of HP1γ at the chromosomal domain and an increased HP1γ mobility, which is not observed for HP1α and HP1β. Surprisingly, MeCP2-induced chromatin unfolding is not associated with transcriptional activation. Our study suggests a novel role for MeCP2 in reorganizing chromatin to facilitate a switch in gene activity.
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Contribution of myocyte enhancer factor 2 family transcription factors to BZLF1 expression in Epstein-Barr virus reactivation from latency. J Virol 2013; 87:10148-62. [PMID: 23843637 DOI: 10.1128/jvi.01002-13] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Reactivation of Epstein-Barr virus (EBV) from latency is dependent on expression of the viral transactivator BZLF1 protein, whose promoter (Zp) normally exhibits only low basal activity but is activated in response to chemical or biological inducers. Using a reporter assay system, we screened for factors that can activate Zp and isolated genes, including those encoding MEF2B, KLF4, and some cellular b-Zip family transcription factors. After confirming their importance and functional binding sites in reporter assays, we prepared recombinant EBV-BAC, in which the binding sites were mutated. Interestingly, the MEF2 mutant virus produced very low levels of BRLF1, another transactivator of EBV, in addition to BZLF1 in HEK293 cells. The virus failed to induce a subset of early genes, such as that encoding BALF5, upon lytic induction, and accordingly, could not replicate to produce progeny viruses in HEK293 cells, but this restriction could be completely lifted by exogenous supply of BRLF1, together with BZLF1. In B cells, induction of BZLF1 by chemical inducers was inhibited by point mutations in the ZII or the three SP1/KLF binding sites of EBV-BAC Zp, while leaky BZLF1 expression was less affected. Mutation of MEF2 sites severely impaired both spontaneous and induced expression of not only BZLF1, but also BRLF1 in comparison to wild-type or revertant virus cases. We also observed that MEF2 mutant EBV featured relatively high repressive histone methylation, such as H3K27me3, but CpG DNA methylation levels were comparable around Zp and the BRLF1 promoter (Rp). These findings shed light on BZLF1 expression and EBV reactivation from latency.
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Kim HS. Genomic impact, chromosomal distribution and transcriptional regulation of HERV elements. Mol Cells 2012; 33:539-44. [PMID: 22562360 PMCID: PMC3887755 DOI: 10.1007/s10059-012-0037-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Revised: 04/10/2012] [Accepted: 04/12/2012] [Indexed: 10/28/2022] Open
Abstract
Human endogenous retroviruses (HERVs) mediate structural variation and genomic instability based on their multiple copy number, inherent ability to mobilize via reverse transcriptase, and high sequence similarity. Moreover, they undergo multiple amplification and retrotransposition events, resulting in the widespread distribution of complete or partial retroviral sequences throughout the primate genome. As such, HERV elements have played important biological roles in genome evolution, and their long terminal repeat (LTR) elements contain numerous regulatory sequences, including effective promoters, enhancers, polyadenylation signals, and transcription factorbinding sites. Lastly, HERV elements are capable of influencing the expression of neighboring genes, a process that also contributed to primate evolution.
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Affiliation(s)
- Heui-Soo Kim
- Department of Biological Sciences, College of Natural Sciences, Pusan National University, Busan 609-735, Korea.
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Hasui K, Wang J, Tanaka Y, Izumo S, Eizuru Y, Matsuyama T. Development of ultra-super sensitive immunohistochemistry and its application to the etiological study of adult T-cell leukemia/lymphoma. Acta Histochem Cytochem 2012; 45:83-106. [PMID: 22685351 PMCID: PMC3365307 DOI: 10.1267/ahc.11034] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Accepted: 02/14/2012] [Indexed: 01/20/2023] Open
Abstract
Antigen retrieval (AR) and ultra-super sensitive immunohistochemistry (ultra-IHC) have been established for application to archival human pathology specimens. The original ultra-IHC was the ImmunoMax method or the catalyzed signal amplification system (ImmunoMax/CSA method), comprising the streptavidin-biotin complex (sABC) method and catalyzed reporter deposition (CARD) reaction with visualization of its deposition. By introducing procedures to diminish non-specific staining in the original ultra-IHC method, we developed the modified ImmunoMax/CSA method with AR heating sections in an AR solution (heating-AR). The heating-AR and modified ImmunoMax/CSA method visualized expression of the predominantly simple present form of HTLV-1 proviral DNA pX region p40Tax protein (Tax) in adult T-cell leukemia/lymphoma (ATLL) cells in archival pathology specimens in approximately 75% of cases. The simple present form of Tax detected exhibited a close relation with ATLL cell proliferation. We also established a new simplified CSA (nsCSA) system by replacing the sABC method with the secondary antibody- and horse radish peroxidase-labeled polymer reagent method, introducing the pretreatments blocking non-specific binding of secondary antibody reagent, and diminishing the diffusion of deposition in the CARD reaction. Combined with AR treating sections with proteinase K solution (enzymatic-AR), the nsCSA system visualized granular immunostaining of the complex present form of Tax in a small number of ATLL cells in most cases, presenting the possibility of etiological pathological diagnosis of ATLL and suggesting that the complex present form of Tax-positive ATLL cells were young cells derived from ATLL stem cells. The heating-AR and ultra-IHC detected physiological expression of the p53 protein and its probable phosphorylation by Tax in peripheral blood mononuclear cells of peripheral blood tissue specimens from HTLV-1 carriers, as well as physiological and pathological expression of the molecules involved with G1 phase progression and G1–S phase transition (E2F-1, E2F-4, DP-1, and cyclin E) in ATLL and peripheral T-cell lymphoma cells. The ultra-IHC with AR is useful for etiological pathological diagnosis of ATLL since HTLV-1 pathogenicity depends on that of Tax, and can be a useful tool for studies translating advanced molecular biology and pathology to human pathology.
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Affiliation(s)
- Kazuhisa Hasui
- Division of Immunology, Department of Infection and Immunity, Institute Research Center (Health Research Course), Kagoshima University Graduate School of Medical and Dental Sciences
- Division of Immunology, Department of Infection and Immunity, Institute Research Center (Health Research Course), Kagoshima University Graduate School of Medical and Dental Sciences
| | - Jia Wang
- Division of Immunology, Department of Infection and Immunity, Institute Research Center (Health Research Course), Kagoshima University Graduate School of Medical and Dental Sciences
- INAMORI Frontier Research Center, Kyushu University
- Division of Immunology, Department of Infection and Immunity, Institute Research Center (Health Research Course), Kagoshima University Graduate School of Medical and Dental Sciences
- INAMORI Frontier Research Center, Kyushu University
| | - Yuetsu Tanaka
- Department of Immunology, Graduate School of Medicine, University of the Ryukyus
- Department of Immunology, Graduate School of Medicine, University of the Ryukyus
| | - Shuji Izumo
- Chronic Viral Diseases Div. of Molecular Pathology, Center for Chronic Viral Diseases (Infection and Immunity), Institute Research Center (Health Research Course), Kagoshima University Graduate School of Medical and Dental Sciences
- Chronic Viral Diseases Div. of Molecular Pathology, Center for Chronic Viral Diseases (Infection and Immunity), Institute Research Center (Health Research Course), Kagoshima University Graduate School of Medical and Dental Sciences
| | - Yoshito Eizuru
- Chronic Viral Diseases Div. of Persistent & Oncogenic Viruses, Center for Chronic Viral Diseases (Infection and Immunity), Institute Research Center (Health Research Course), Kagoshima University Graduate School of Medical and Dental Sciences
- Chronic Viral Diseases Div. of Persistent & Oncogenic Viruses, Center for Chronic Viral Diseases (Infection and Immunity), Institute Research Center (Health Research Course), Kagoshima University Graduate School of Medical and Dental Sciences
| | - Takami Matsuyama
- Division of Immunology, Department of Infection and Immunity, Institute Research Center (Health Research Course), Kagoshima University Graduate School of Medical and Dental Sciences
- Division of Immunology, Department of Infection and Immunity, Institute Research Center (Health Research Course), Kagoshima University Graduate School of Medical and Dental Sciences
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Murata T, Noda C, Saito S, Kawashima D, Sugimoto A, Isomura H, Kanda T, Yokoyama KK, Tsurumi T. Involvement of Jun dimerization protein 2 (JDP2) in the maintenance of Epstein-Barr virus latency. J Biol Chem 2011; 286:22007-16. [PMID: 21525011 DOI: 10.1074/jbc.m110.199836] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Reactivation of the Epstein-Barr virus from latency is dependent on expression of the BZLF1 viral immediate-early protein. The BZLF1 promoter (Zp) normally exhibits only low basal activity but is activated in response to chemical inducers such as 12-O-tetradecanoylphorbol-13-acetate and calcium ionophore. We found that Jun dimerization protein 2 (JDP2) plays a significant role in suppressing Zp activity. Reporter, EMSA, and ChIP assays of a Zp mutant virus revealed JDP2 association with Zp at the ZII cis-element, a binding site for CREB/ATF/AP-1. Suppression of Zp activity by JDP2 correlated with HDAC3 association and reduced levels of histone acetylation. Although introduction of point mutations into the ZII element of the viral genome did not increase the level of BZLF1 production, silencing of endogenous JDP2 gene expression by RNA interference increased the levels of viral early gene products and viral DNA replication. These results indicate that JDP2 plays a role as a repressor of Zp and that its replacement by CREB/ATF/AP-1 at ZII is crucial to triggering reactivation from latency to lytic replication.
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Affiliation(s)
- Takayuki Murata
- Division of Virology, Aichi Cancer Center Research Institute, 1-1, Kanokoden, Chikusa-ku, Nagoya 464-8681, Japan
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B1, a Novel Amonafide Analogue, Overcomes the Resistance Conferred by Bcl-2 in Human Promyelocytic Leukemia HL60 Cells. Mol Cancer Res 2010; 8:1619-32. [DOI: 10.1158/1541-7786.mcr-10-0341] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Joulie M, Miotto B, Defossez PA. Mammalian methyl-binding proteins: What might they do? Bioessays 2010; 32:1025-32. [DOI: 10.1002/bies.201000057] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2010] [Revised: 08/19/2010] [Accepted: 08/24/2010] [Indexed: 12/12/2022]
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Pierard V, Guiguen A, Colin L, Wijmeersch G, Vanhulle C, Van Driessche B, Dekoninck A, Blazkova J, Cardona C, Merimi M, Vierendeel V, Calomme C, Nguyên TLA, Nuttinck M, Twizere JC, Kettmann R, Portetelle D, Burny A, Hirsch I, Rohr O, Van Lint C. DNA cytosine methylation in the bovine leukemia virus promoter is associated with latency in a lymphoma-derived B-cell line: potential involvement of direct inhibition of cAMP-responsive element (CRE)-binding protein/CRE modulator/activation transcription factor binding. J Biol Chem 2010; 285:19434-49. [PMID: 20413592 PMCID: PMC2885223 DOI: 10.1074/jbc.m110.107607] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2010] [Revised: 03/31/2010] [Indexed: 02/02/2023] Open
Abstract
Bovine leukemia virus (BLV) proviral latency represents a viral strategy to escape the host immune system and allow tumor development. Besides the previously demonstrated role of histone deacetylation in the epigenetic repression of BLV expression, we showed here that BLV promoter activity was induced by several DNA methylation inhibitors (such as 5-aza-2'-deoxycytidine) and that overexpressed DNMT1 and DNMT3A, but not DNMT3B, down-regulated BLV promoter activity. Importantly, cytosine hypermethylation in the 5'-long terminal repeat (LTR) U3 and R regions was associated with true latency in the lymphoma-derived B-cell line L267 but not with defective latency in YR2 cells. Moreover, the virus-encoded transactivator Tax(BLV) decreased DNA methyltransferase expression levels, which could explain the lower level of cytosine methylation observed in the L267(LTaxSN) 5'-LTR compared with the L267 5'-LTR. Interestingly, DNA methylation inhibitors and Tax(BLV) synergistically activated BLV promoter transcriptional activity in a cAMP-responsive element (CRE)-dependent manner. Mechanistically, methylation at the -154 or -129 CpG position (relative to the transcription start site) impaired in vitro binding of CRE-binding protein (CREB) transcription factors to their respective CRE sites. Methylation at -129 CpG alone was sufficient to decrease BLV promoter-driven reporter gene expression by 2-fold. We demonstrated in vivo the recruitment of CREB/CRE modulator (CREM) and to a lesser extent activating transcription factor-1 (ATF-1) to the hypomethylated CRE region of the YR2 5'-LTR, whereas we detected no CREB/CREM/ATF recruitment to the hypermethylated corresponding region in the L267 cells. Altogether, these findings suggest that site-specific DNA methylation of the BLV promoter represses viral transcription by directly inhibiting transcription factor binding, thereby contributing to true proviral latency.
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Affiliation(s)
- Valérie Pierard
- From the Laboratoire de Virologie Moléculaire, Institut de Biologie et de Médecine Moléculaires (IBMM), Université Libre de Bruxelles, Rue des Profs Jeener et Brachet 12, 6041 Gosselies, Belgium
| | - Allan Guiguen
- From the Laboratoire de Virologie Moléculaire, Institut de Biologie et de Médecine Moléculaires (IBMM), Université Libre de Bruxelles, Rue des Profs Jeener et Brachet 12, 6041 Gosselies, Belgium
| | - Laurence Colin
- From the Laboratoire de Virologie Moléculaire, Institut de Biologie et de Médecine Moléculaires (IBMM), Université Libre de Bruxelles, Rue des Profs Jeener et Brachet 12, 6041 Gosselies, Belgium
| | - Gaëlle Wijmeersch
- From the Laboratoire de Virologie Moléculaire, Institut de Biologie et de Médecine Moléculaires (IBMM), Université Libre de Bruxelles, Rue des Profs Jeener et Brachet 12, 6041 Gosselies, Belgium
| | - Caroline Vanhulle
- From the Laboratoire de Virologie Moléculaire, Institut de Biologie et de Médecine Moléculaires (IBMM), Université Libre de Bruxelles, Rue des Profs Jeener et Brachet 12, 6041 Gosselies, Belgium
| | - Benoît Van Driessche
- From the Laboratoire de Virologie Moléculaire, Institut de Biologie et de Médecine Moléculaires (IBMM), Université Libre de Bruxelles, Rue des Profs Jeener et Brachet 12, 6041 Gosselies, Belgium
| | - Ann Dekoninck
- From the Laboratoire de Virologie Moléculaire, Institut de Biologie et de Médecine Moléculaires (IBMM), Université Libre de Bruxelles, Rue des Profs Jeener et Brachet 12, 6041 Gosselies, Belgium
| | - Jana Blazkova
- the Institut de Cancérologie de Marseille, UMR 599 INSERM, Institut Paoli-Calmettes, Université de la Méditerranée, Boulevard Lei Roure 27, 13009 Marseille, France
| | - Christelle Cardona
- From the Laboratoire de Virologie Moléculaire, Institut de Biologie et de Médecine Moléculaires (IBMM), Université Libre de Bruxelles, Rue des Profs Jeener et Brachet 12, 6041 Gosselies, Belgium
| | - Makram Merimi
- the Laboratory of Experimental Hematology, Institut Jules Bordet, Université Libre de Bruxelles, Boulevard de Waterloo 121, 1000 Bruxelles, Belgium
| | - Valérie Vierendeel
- From the Laboratoire de Virologie Moléculaire, Institut de Biologie et de Médecine Moléculaires (IBMM), Université Libre de Bruxelles, Rue des Profs Jeener et Brachet 12, 6041 Gosselies, Belgium
| | - Claire Calomme
- From the Laboratoire de Virologie Moléculaire, Institut de Biologie et de Médecine Moléculaires (IBMM), Université Libre de Bruxelles, Rue des Profs Jeener et Brachet 12, 6041 Gosselies, Belgium
| | - Thi Liên-Anh Nguyên
- From the Laboratoire de Virologie Moléculaire, Institut de Biologie et de Médecine Moléculaires (IBMM), Université Libre de Bruxelles, Rue des Profs Jeener et Brachet 12, 6041 Gosselies, Belgium
| | - Michèle Nuttinck
- the Département de Biologie Moléculaire, Faculté Universitaire des Sciences Agronomiques de Gembloux, Avenue du Maréchal Juin 6, 5030 Gembloux, Belgium, and
| | - Jean-Claude Twizere
- the Département de Biologie Moléculaire, Faculté Universitaire des Sciences Agronomiques de Gembloux, Avenue du Maréchal Juin 6, 5030 Gembloux, Belgium, and
| | - Richard Kettmann
- the Département de Biologie Moléculaire, Faculté Universitaire des Sciences Agronomiques de Gembloux, Avenue du Maréchal Juin 6, 5030 Gembloux, Belgium, and
| | - Daniel Portetelle
- the Département de Biologie Moléculaire, Faculté Universitaire des Sciences Agronomiques de Gembloux, Avenue du Maréchal Juin 6, 5030 Gembloux, Belgium, and
| | - Arsène Burny
- the Département de Biologie Moléculaire, Faculté Universitaire des Sciences Agronomiques de Gembloux, Avenue du Maréchal Juin 6, 5030 Gembloux, Belgium, and
| | - Ivan Hirsch
- the Institut de Cancérologie de Marseille, UMR 599 INSERM, Institut Paoli-Calmettes, Université de la Méditerranée, Boulevard Lei Roure 27, 13009 Marseille, France
| | - Olivier Rohr
- the Institut Universitaire de Technologie Louis Pasteur de Schiltigheim, University of Strasbourg, 1 Allée d'Athènes, 67300 Schiltigheim, France
| | - Carine Van Lint
- From the Laboratoire de Virologie Moléculaire, Institut de Biologie et de Médecine Moléculaires (IBMM), Université Libre de Bruxelles, Rue des Profs Jeener et Brachet 12, 6041 Gosselies, Belgium
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Ding DC, Chiang MH, Lai HC, Hsiung CA, Hsieh CY, Chu TY. Methylation of the long control region of HPV16 is related to the severity of cervical neoplasia. Eur J Obstet Gynecol Reprod Biol 2009; 147:215-20. [PMID: 19819061 DOI: 10.1016/j.ejogrb.2009.08.023] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2009] [Revised: 06/29/2009] [Accepted: 08/18/2009] [Indexed: 10/20/2022]
Abstract
OBJECTIVE Oncogenic human papillomavirus (HPV) is the cause of cervical cancer. Hypermethylation of the CpG islands located at the long control region (LCR) of the HPV genome may regulate the expression of the major oncogenes E6 and E7, and may relate to cancer progression. The goal of the present study was to investigate the methylation patterns of CpG dinucleotides contained within the LCR of the HPV16 genome in a collection of clinical specimens comprising the full spectrum of cervical carcinogenesis. STUDY DESIGN The status of LCR methylation was investigated in HPV16-infected cervical precancer and cancer cell lines, and in HPV16-infected low-grade squamous intraepithelial lesion of cervix (LSIL, n=17), high-grade squamous intraepithelial lesion (HSIL, n=21) and invasive squamous cell carcinoma (SCC, n=15) by bisulfite sequencing. RESULTS Among the three CpG islands of HPV16 LCR, methylation was found in three in the CaSki cell, in two upstream ones in SiHa cell, and none in the precancerous Z172 cell. Reactivation of E6 gene expression upon demethylation by 5-aza-dC and TSA treatments was noted in CaSki cells. In HPV-infected cervical specimens, progressive methylation of HPV16 LCR was noted, with rates of 5.9%, 33.3% and 53.3% in LSIL, HSIL and SCC, respectively (P<0.01). A trend toward increasing density of CpG methylation was also noted. Topologically, more methylated sites were found at the E6/E7 promoter region in SCC, compared with LSIL and HSIL. CONCLUSION The study disclosed downregulation of E6 gene transcription by LCR methylation in cervical cancer cells. Methylation of HPV 16 LCR is highly associated with severity of cervical neoplasm.
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Affiliation(s)
- Dah-Ching Ding
- Department of Obstetrics and Gynecology, Buddhist Tzu Chi General Hospital, Tzu Chi University, Hualien, Taiwan, ROC
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18
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Bogdanović O, Veenstra GJC. DNA methylation and methyl-CpG binding proteins: developmental requirements and function. Chromosoma 2009; 118:549-65. [PMID: 19506892 PMCID: PMC2729420 DOI: 10.1007/s00412-009-0221-9] [Citation(s) in RCA: 320] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2009] [Revised: 05/19/2009] [Accepted: 05/27/2009] [Indexed: 02/06/2023]
Abstract
DNA methylation is a major epigenetic modification in the genomes of higher eukaryotes. In vertebrates, DNA methylation occurs predominantly on the CpG dinucleotide, and approximately 60% to 90% of these dinucleotides are modified. Distinct DNA methylation patterns, which can vary between different tissues and developmental stages, exist on specific loci. Sites of DNA methylation are occupied by various proteins, including methyl-CpG binding domain (MBD) proteins which recruit the enzymatic machinery to establish silent chromatin. Mutations in the MBD family member MeCP2 are the cause of Rett syndrome, a severe neurodevelopmental disorder, whereas other MBDs are known to bind sites of hypermethylation in human cancer cell lines. Here, we review the advances in our understanding of the function of DNA methylation, DNA methyltransferases, and methyl-CpG binding proteins in vertebrate embryonic development. MBDs function in transcriptional repression and long-range interactions in chromatin and also appear to play a role in genomic stability, neural signaling, and transcriptional activation. DNA methylation makes an essential and versatile epigenetic contribution to genome integrity and function.
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Affiliation(s)
- Ozren Bogdanović
- Department of Molecular Biology, Faculty of Science, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen, Nijmegen, The Netherlands
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19
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Mittler G, Butter F, Mann M. A SILAC-based DNA protein interaction screen that identifies candidate binding proteins to functional DNA elements. Genes Dev 2009; 19:284-93. [PMID: 19015324 PMCID: PMC2652210 DOI: 10.1101/gr.081711.108] [Citation(s) in RCA: 134] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2008] [Accepted: 11/04/2008] [Indexed: 12/15/2022]
Abstract
Determining the underlying logic that governs the networks of gene expression in higher eukaryotes is an important task in the post-genome era. Sequence-specific transcription factors (TFs) that can read the genetic regulatory information and proteins that interpret the information provided by CpG methylation are crucial components of the system that controls the transcription of protein-coding genes by RNA polymerase II. We have previously described Stable Isotope Labeling by Amino acids in Cell culture (SILAC) for the quantitative comparison of proteomes and the determination of protein-protein interactions. Here, we report a generic and scalable strategy to uncover such DNA protein interactions by SILAC that uses a fast and simple one-step affinity capture of TFs from crude nuclear extracts. Employing mutated or nonmethylated control oligonucleotides, specific TFs binding to their wild-type or methyl-CpG bait are distinguished from the vast excess of copurifying background proteins by their peptide isotope ratios that are determined by mass spectrometry. Our proof of principle screen identifies several proteins that have not been previously reported to be present on the fully methylated CpG island upstream of the human metastasis associated 1 family, member 2 gene promoter. The approach is robust, sensitive, and specific and offers the potential for high-throughput determination of TF binding profiles.
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Affiliation(s)
- Gerhard Mittler
- Center for Experimental Bioinformatics, University of Southern Denmark, DK-5230 Odense M, Denmark
- BIOSS—Center of Biological Signalling Studies, Albert-Ludwigs-University Freiburg, D-79104 Freiburg, Germany
| | - Falk Butter
- Department of Proteomics and Signal Transduction, Max-Planck-Institute for Biochemistry, D-82152 Martinsried, Germany
| | - Matthias Mann
- Department of Proteomics and Signal Transduction, Max-Planck-Institute for Biochemistry, D-82152 Martinsried, Germany
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20
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Murata T, Sato Y, Nakayama S, Kudoh A, Iwahori S, Isomura H, Tajima M, Hishiki T, Ohshima T, Hijikata M, Shimotohno K, Tsurumi T. TORC2, a coactivator of cAMP-response element-binding protein, promotes Epstein-Barr virus reactivation from latency through interaction with viral BZLF1 protein. J Biol Chem 2009; 284:8033-41. [PMID: 19164291 DOI: 10.1074/jbc.m808466200] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Reactivation of the Epstein-Barr virus from latency is dependent on expression of the viral BZLF1 protein. The BZLF1 promoter (Zp) normally exhibits only low basal activity but is activated in response to chemical inducers such as 12-O-tetradecanoylphorbol-13-acetate and calcium ionophore. We found here that Transducer of Regulated cAMP-response Element-binding Protein (CREB) (TORC) 2 enhances Zp activity 10-fold and more than 100-fold with co-expression of the BZLF1 protein. Mutational analysis of Zp revealed that the activation by TORC is dependent on ZII and ZIII cis elements, binding sites for CREB family transcriptional factors and the BZLF1 protein, respectively. Immunoprecipitation, chromatin immunoprecipitation, and reporter assay using Gal4-luc and Gal4BD-BZLF1 fusion protein indicate that TORC2 interacts with BZLF1, and that the complex is efficiently recruited onto Zp. These observations clearly indicate that TORC2 activates the promoter through interaction with the BZLF1 protein as well as CREB family transcriptional factors. Induction of the lytic replication resulted in the translocation of TORC2 from cytoplasm to viral replication compartments in nuclei, and furthermore, activation of Zp by TORC2 was augmented by calcium-regulated phosphatase, calcineurin. Silencing of endogenous TORC2 gene expression by RNA interference decreased the levels of the BZLF1 protein in response to 12-O-tetradecanoylphorbol-13-acetate/ionophore. Based on these results, we conclude that Epstein-Barr virus exploits the calcineurin-TORC signaling pathway through interactions between TORC and the BZLF1 protein in reactivation from latency.
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Affiliation(s)
- Takayuki Murata
- Division of Virology, Aichi Cancer Center Research Institute, 1-1, Kanokoden, Chikusa-ku, Nagoya 464-8681, Japan
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21
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Boxus M, Twizere JC, Legros S, Dewulf JF, Kettmann R, Willems L. The HTLV-1 Tax interactome. Retrovirology 2008; 5:76. [PMID: 18702816 PMCID: PMC2533353 DOI: 10.1186/1742-4690-5-76] [Citation(s) in RCA: 195] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2008] [Accepted: 08/14/2008] [Indexed: 12/22/2022] Open
Abstract
The Tax1 oncoprotein encoded by Human T-lymphotropic virus type I is a major determinant of viral persistence and pathogenesis. Tax1 affects a wide variety of cellular signalling pathways leading to transcriptional activation, proliferation and ultimately transformation. To carry out these functions, Tax1 interacts with and modulates activity of a number of cellular proteins. In this review, we summarize the present knowledge of the Tax1 interactome and propose a rationale for the broad range of cellular proteins identified so far.
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Affiliation(s)
- Mathieu Boxus
- University Academia Wallonie-Europe, Molecular and Cellular Biology at FUSAGx, Gembloux, Belgium.
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22
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Szyf M. DNA demethylation and cancer metastasis: therapeutic implications. Expert Opin Drug Discov 2008; 3:519-31. [DOI: 10.1517/17460441.3.5.519] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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23
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Tshuikina M, Nilsson K, Öberg F. Positive histone marks are associated with active transcription from a methylated ICSBP/IRF8 gene. Gene 2008; 410:259-67. [DOI: 10.1016/j.gene.2007.12.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2007] [Revised: 12/04/2007] [Accepted: 12/13/2007] [Indexed: 12/20/2022]
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24
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Abstract
Within the human genome there are hundreds of copies of the rRNA gene, but only a fraction of these genes are active. Silencing through epigenetics has been extensively studied; however, it is essential to understand how active rRNA genes are maintained. Here, we propose a role for the methyl-CpG binding domain protein MBD3 in epigenetically maintaining active rRNA promoters. We show that MBD3 is localized to the nucleolus, colocalizes with upstream binding factor, and binds to unmethylated rRNA promoters. Knockdown of MBD3 by small interfering RNA results in increased methylation of the rRNA promoter coupled with a decrease in RNA polymerase I binding and pre-rRNA transcription. Conversely, overexpression of MBD3 results in decreased methylation of the rRNA promoter. Additionally, overexpression of MBD3 induces demethylation of nonreplicating plasmids containing the rRNA promoter. We demonstrate that this demethylation occurs following the overexpression of MBD3 and its increased interaction with the methylated rRNA promoter. This is the first demonstration that MBD3 is involved in inducing and maintaining the demethylated state of a specific promoter.
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Affiliation(s)
- Shelley E Brown
- Department of Pharmacology and Therapeutics, McGill University, 3655 Sir William Osler Promenade, Montréal, Québec H3G 1Y6, Canada
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25
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D'Alessio AC, Szyf M. Epigenetic tête-à-tête: the bilateral relationship between chromatin modifications and DNA methylation. Biochem Cell Biol 2007; 84:463-76. [PMID: 16936820 DOI: 10.1139/o06-090] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The epigenome, which comprises chromatin, associated proteins, and the pattern of covalent modification of DNA by methylation, sets up and maintains gene expression programs. It was originally believed that DNA methylation was the dominant reaction in determining the chromatin structure. However, emerging data suggest that chromatin can affect DNA methylation in both directions, triggering either de novo DNA methylation or demethylation. These events are particularly important for the understanding of cellular transformation, which requires a coordinated change in gene expression profiles. While genetic alterations can explain some of the changes, the important role of epigenetic reprogramming is becoming more and more evident. Cancer cells exhibit a paradoxical coexistence of global loss of DNA methylation with regional hypermethylation.
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Affiliation(s)
- Ana C D'Alessio
- Department of Pharmacology and Therapeutics, McGill University, 3655 Promenade Sir William Osler, Montreal, QC H3G 1Y6, Canada
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26
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Pulukuri SM, Rao JS. CpG island promoter methylation and silencing of 14-3-3sigma gene expression in LNCaP and Tramp-C1 prostate cancer cell lines is associated with methyl-CpG-binding protein MBD2. Oncogene 2006; 25:4559-72. [PMID: 16786000 PMCID: PMC1526774 DOI: 10.1038/sj.onc.1209462] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
14-3-3sigma proteins regulate numerous cellular processes that are important to cancer development. One of its biological roles involves G2 cell-cycle arrest following DNA damage. It has also been reported that the loss of 14-3-3sigma expression via CpG methylation may contribute to malignant transformation by impairing the G2 cell-cycle checkpoint function, thereby allowing an accumulation of genetic defects. However, how the CpG methylation-dependent silencing mechanism works in relation to promoter methylation associated with methyl-CpG-binding proteins (MeCPs) is still unclear. To better understand the mechanism, we first examined the methylation status of the 14-3-3sigma promoter-associated CpG islands and 14-3-3sigma gene expression in a subset of prostate cancer cell lines using methylation-specific PCR (MSP), an HhaI-based DNA methylation assay, and reverse transcription-PCR (RT-PCR). We found that the 14-3-3sigma expression is lost in LNCaP and Tramp-C1 prostate cancer cell lines and that this expression is restored after treatment with epigenetic silencing modifiers 5-aza-2'-deoxycytidine (5-aza) and trichostatin A (TSA). These results imply transcriptional silencing via promoter-associated CpG methylation. Chromatin immunoprecipitation analysis revealed that methyl-CpG-binding protein 2 (MBD2) is associated preferentially to the methylated CpG island in the 14-3-3sigma promoter in LNCaP and Tramp-C1 cells but not in 14-3-3sigma-expressing PC3 and DU145 cells, which contain an unmethylated CpG island in the 14-3-3sigma promoter region. The 14-3-3sigma gene silencing because of CpG methylation correlates with binding of MBD2. In addition, the activation of 14-3-3sigma gene expression by a combination of 5-aza and TSA also involves the release of the MBD2 from the 14-3-3sigma promoter-methylated CpG island in LNCaP and Tramp-C1 cells. Furthermore, MBD2 knockdown by siRNA stimulated 14-3-3sigma expression in LNCaP cells. We also investigated whether the loss of 14-3-3sigma expression in LNCaP and Tramp-C1 cells affects cell proliferation by MTT assays. Interestingly, we observed that 14-3-3sigma-inactivated LNCaP and Tramp-C1 cells had markedly decreased cell proliferation and protein expression of proliferation cell nuclear antigen (PCNA) after restoration of 14-3-3sigma expression with 5-aza and TSA treatment. On the other hand, the same treatment did not significantly affect 14-3-3sigma-active PC3 and DU145 cells, which normally express 14-3-3sigma. Finally, 14-3-3sigma knockdown by siRNA resulted in increased proliferation in PC3 and DU145 cells. These findings suggest that the transcriptional silencing of the 14-3-3sigma gene is caused by promoter CpG island methylation associated with MBD2, and that this may play an important role in prostate cancer progression during the invasive and metastatic stages of the disease.
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Affiliation(s)
- S M Pulukuri
- Program of Cancer Biology, Department of Biomedical and Therapeutic Sciences, University of Illinois College of Medicine, Peoria, IL 61656, USA
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27
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Angrisano T, Lembo F, Pero R, Natale F, Fusco A, Avvedimento VE, Bruni CB, Chiariotti L. TACC3 mediates the association of MBD2 with histone acetyltransferases and relieves transcriptional repression of methylated promoters. Nucleic Acids Res 2006; 34:364-72. [PMID: 16410616 PMCID: PMC1331987 DOI: 10.1093/nar/gkj400] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We have recently reported that a novel MBD2 interactor (MBDin) has the capacity to reactivate transcription from MBD2-repressed methylated promoters even in the absence of demethylation events. Here we show that another unrelated protein, TACC3, displays a similar activity on methylated genes. In addition the data reported here provide possible molecular mechanisms for the observed phenomenon. Immunoprecipitation experiments showed that MBD2/TACC3 form a complex in vivo with the histone acetyltransferase pCAF. MBD2 could also associate with HDAC2, a component of MeCP1 repression complex. However, we found that the complexes formed by MBD2 with TACC3/pCAF and with HDAC2 were mutually exclusive. Moreover, HAT enzymatic assays demonstrated that HAT activity associates with MBD2 in vivo and that such association significantly increased when TACC3 was over-expressed. Overall our findings suggest that TACC3 can be recruited by MBD2 on methylated promoters and is able to reactivate transcription possibly by favoring the formation of an HAT-containing MBD2 complex and, thus, switching the repression potential of MBD2 in activation even prior to eventual demethylation.
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Affiliation(s)
- Tiziana Angrisano
- Dipartimento di Biologia e Patologia Cellulare e Molecolare ‘L. Califano’, Università degli Studi di Napoli ‘Federico II’80131 Naples, Italy
| | - Francesca Lembo
- Dipartimento di Chimica Farmaceutica e Tossicologica, Università degli Studi di Napoli ‘Federico II’80131 Naples, Italy
| | - Raffaela Pero
- Dipartimento di Biologia e Patologia Cellulare e Molecolare ‘L. Califano’, Università degli Studi di Napoli ‘Federico II’80131 Naples, Italy
| | - Francesco Natale
- Dipartimento di Biologia e Patologia Cellulare e Molecolare ‘L. Califano’, Università degli Studi di Napoli ‘Federico II’80131 Naples, Italy
| | - Alfredo Fusco
- Dipartimento di Biologia e Patologia Cellulare e Molecolare ‘L. Califano’, Università degli Studi di Napoli ‘Federico II’80131 Naples, Italy
- NOGEC, Naples Oncogenomic Center, CEINGE Biotecnologie AvanzateNaples, Italy
| | - Vittorio E. Avvedimento
- Dipartimento di Biologia e Patologia Cellulare e Molecolare ‘L. Califano’, Università degli Studi di Napoli ‘Federico II’80131 Naples, Italy
- NOGEC, Naples Oncogenomic Center, CEINGE Biotecnologie AvanzateNaples, Italy
| | - Carmelo B. Bruni
- Dipartimento di Biologia e Patologia Cellulare e Molecolare ‘L. Califano’, Università degli Studi di Napoli ‘Federico II’80131 Naples, Italy
| | - Lorenzo Chiariotti
- Dipartimento di Biologia e Patologia Cellulare e Molecolare ‘L. Califano’, Università degli Studi di Napoli ‘Federico II’80131 Naples, Italy
- Dipartimento di Scienze per la Salute, Università degli Studi del Molise86100 Campobasso, Italy
- NOGEC, Naples Oncogenomic Center, CEINGE Biotecnologie AvanzateNaples, Italy
- To whom correspondence should be addressed. Tel: +39 081 7462056; Fax: +39 081 7703285;
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