201
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Morikawa H, Sakaguchi S. Genetic and epigenetic basis of Treg cell development and function: from a FoxP3-centered view to an epigenome-defined view of natural Treg cells. Immunol Rev 2014; 259:192-205. [DOI: 10.1111/imr.12174] [Citation(s) in RCA: 131] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Hiromasa Morikawa
- Laboratory of Experimental Immunology; WPI Immunology Frontier Research Center; Osaka University; Osaka Japan
| | - Shimon Sakaguchi
- Laboratory of Experimental Immunology; WPI Immunology Frontier Research Center; Osaka University; Osaka Japan
- Department of Experimental Pathology; Institute for Frontier Medical Sciences; Kyoto University; Kyoto Japan
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202
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Differential roles of epigenetic changes and Foxp3 expression in regulatory T cell-specific transcriptional regulation. Proc Natl Acad Sci U S A 2014; 111:5289-94. [PMID: 24706905 DOI: 10.1073/pnas.1312717110] [Citation(s) in RCA: 96] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Naturally occurring regulatory T (Treg) cells, which specifically express the transcription factor forkhead box P3 (Foxp3), are engaged in the maintenance of immunological self-tolerance and homeostasis. By transcriptional start site cluster analysis, we assessed here how genome-wide patterns of DNA methylation or Foxp3 binding sites were associated with Treg-specific gene expression. We found that Treg-specific DNA hypomethylated regions were closely associated with Treg up-regulated transcriptional start site clusters, whereas Foxp3 binding regions had no significant correlation with either up- or down-regulated clusters in nonactivated Treg cells. However, in activated Treg cells, Foxp3 binding regions showed a strong correlation with down-regulated clusters. In accordance with these findings, the above two features of activation-dependent gene regulation in Treg cells tend to occur at different locations in the genome. The results collectively indicate that Treg-specific DNA hypomethylation is instrumental in gene up-regulation in steady state Treg cells, whereas Foxp3 down-regulates the expression of its target genes in activated Treg cells. Thus, the two events seem to play distinct but complementary roles in Treg-specific gene expression.
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203
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Estève PO, Terragni J, Deepti K, Chin HG, Dai N, Espejo A, Corrêa IR, Bedford MT, Pradhan S. Methyllysine reader plant homeodomain (PHD) finger protein 20-like 1 (PHF20L1) antagonizes DNA (cytosine-5) methyltransferase 1 (DNMT1) proteasomal degradation. J Biol Chem 2014; 289:8277-87. [PMID: 24492612 PMCID: PMC3961655 DOI: 10.1074/jbc.m113.525279] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Revised: 01/31/2014] [Indexed: 11/28/2022] Open
Abstract
Inheritance of DNA cytosine methylation pattern during successive cell division is mediated by maintenance DNA (cytosine-5) methyltransferase 1 (DNMT1). Lysine 142 of DNMT1 is methylated by the SET domain containing lysine methyltransferase 7 (SET7), leading to its degradation by proteasome. Here we show that PHD finger protein 20-like 1 (PHF20L1) regulates DNMT1 turnover in mammalian cells. Malignant brain tumor (MBT) domain of PHF20L1 binds to monomethylated lysine 142 on DNMT1 (DNMT1K142me1) and colocalizes at the perinucleolar space in a SET7-dependent manner. PHF20L1 knockdown by siRNA resulted in decreased amounts of DNMT1 on chromatin. Ubiquitination of DNMT1K142me1 was abolished by overexpression of PHF20L1, suggesting that its binding may block proteasomal degradation of DNMT1K142me1. Conversely, siRNA-mediated knockdown of PHF20L1 or incubation of a small molecule MBT domain binding inhibitor in cultured cells accelerated the proteasomal degradation of DNMT1. These results demonstrate that the MBT domain of PHF20L1 reads and controls enzyme levels of methylated DNMT1 in cells, thus representing a novel antagonist of DNMT1 degradation.
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Affiliation(s)
| | - Jolyon Terragni
- From New England Biolabs Inc., Ipswich, Massachusetts 01938 and
| | | | | | - Nan Dai
- From New England Biolabs Inc., Ipswich, Massachusetts 01938 and
| | - Alexsandra Espejo
- the Department of Molecular Carcinogenesis, University of Texas M.D. Anderson Cancer Center, Smithville, Texas 78957
| | - Ivan R. Corrêa
- From New England Biolabs Inc., Ipswich, Massachusetts 01938 and
| | - Mark T. Bedford
- the Department of Molecular Carcinogenesis, University of Texas M.D. Anderson Cancer Center, Smithville, Texas 78957
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204
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Ahmed AA, Ma W, Ni Y, Zhou Q, Zhao R. Embryonic exposure to corticosterone modifies aggressive behavior through alterations of the hypothalamic pituitary adrenal axis and the serotonergic system in the chicken. Horm Behav 2014; 65:97-105. [PMID: 24333411 DOI: 10.1016/j.yhbeh.2013.12.002] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Revised: 11/28/2013] [Accepted: 12/04/2013] [Indexed: 12/18/2022]
Abstract
Exposure to excess glucocorticoids (GCs) during embryonic development influences offspring phenotypes and behaviors and induces epigenetic modifications of the genes in the hypothalamic-pituitary-adrenal (HPA) axis and in the serotonergic system in mammals. Whether prenatal corticosterone (CORT) exposure causes similar effects in avian species is less clear. In this study, we injected low (0.2μg) and high (1μg) doses of CORT into developing embryos on day 11 of incubation (E11) and tested the changes in aggressive behavior and hypothalamic gene expression on posthatch chickens of different ages. In ovo administration of high dose CORT significantly suppressed the growth rate from 3weeks of age and increased the frequency of aggressive behaviors, and the dosage was associated with elevated plasma CORT concentrations and significantly downregulated hypothalamic expression of arginine vasotocin (AVT) and corticotropin-releasing hormone (CRH). The hypothalamic content of glucocorticoid receptor (GR) protein was significantly decreased in the high dose group (p<0.05), whereas no changes were observed for GR mRNA. High dose CORT exposure significantly increased platelet serotonin (5-HT) uptake, decreased whole blood 5-HT concentration (p<0.05), downregulated hypothalamic tryptophan hydroxylase 1 (TPH1) mRNA and upregulated 5-HT receptor 1A (5-HTR1A) and monoamine oxidase A (MAO-A) mRNA, but not monoamine oxidase B (MAO-B). High dose CORT also significantly increased DNA methylation of the hypothalamic GR and CRH gene promoters (p<0.05). Our findings suggest that embryonic exposure to CORT programs aggressive behavior in the chicken through alterations of the HPA axis and the serotonergic system, which may involve modifications in DNA methylation.
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Affiliation(s)
- Abdelkareem A Ahmed
- Key Laboratory of Animal Physiology and Biochemistry, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China
| | - Wenqiang Ma
- Key Laboratory of Animal Physiology and Biochemistry, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China
| | - Yingdong Ni
- Key Laboratory of Animal Physiology and Biochemistry, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China
| | - Qin Zhou
- Key Laboratory of Animal Physiology and Biochemistry, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China
| | - Ruqian Zhao
- Key Laboratory of Animal Physiology and Biochemistry, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China.
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205
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Bian EB, Zong G, Xie YS, Meng XM, Huang C, Li J, Zhao B. TET family proteins: new players in gliomas. J Neurooncol 2014; 116:429-35. [PMID: 24395347 DOI: 10.1007/s11060-013-1328-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Accepted: 12/27/2013] [Indexed: 12/31/2022]
Abstract
DNA methylation at the 5-position of cytosine (5mC) in the mammalian genome has emerged as a pivotal epigenetic event that plays important roles in development, aging and disease. The three members of the TET protein family, which convert 5mC to 5-hydroxymethylcytosine, has provided a potential mechanism resulting in DNA demethylation and maintaining cellular identity. Recent studies have shown that epigenetic modifications play a key role in the regulation of the molecular pathogenesis of gliomas. In this review we focus on demonstrating the TET proteins in DNA demethylation and transcriptional regulation of different target genes. In addition, we address the role of TET proteins in gliomas. This review will provide valuable insights into the potential targets of gliomas, and may open the possibility of novel therapeutic approaches to this fatal disease.
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Affiliation(s)
- Er-Bao Bian
- Department of Neurosurgery, The Second Affiliated Hospital of Anhui Medical University, Hefei, 230601, China
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206
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Abstract
Although all neurons carry the same genetic information, they vary considerably in morphology and functions and respond differently to environmental conditions. Such variability results mostly from differences in gene expression. Among the processes that regulate gene activity, epigenetic mechanisms play a key role and provide an additional layer of complexity to the genome. They allow the dynamic modulation of gene expression in a locus- and cell-specific manner. These mechanisms primarily involve DNA methylation, posttranslational modifications (PTMs) of histones and noncoding RNAs that together remodel chromatin and facilitate or suppress gene expression. Through these mechanisms, the brain gains high plasticity in response to experience and can integrate and store new information to shape future neuronal and behavioral responses. Dynamic epigenetic footprints underlying the plasticity of brain cells and circuits contribute to the persistent impact of life experiences on an individual's behavior and physiology ranging from the formation of long-term memory to the sequelae of traumatic events or of drug addiction. They also contribute to the way lifestyle, life events, or exposure to environmental toxins can predispose an individual to disease. This chapter describes the most prominent examples of epigenetic marks associated with long-lasting changes in the brain induced by experience. It discusses the role of epigenetic processes in behavioral plasticity triggered by environmental experiences. A particular focus is placed on learning and memory where the importance of epigenetic modifications in brain circuits is best understood. The relevance of epigenetics in memory disorders such as dementia and Alzheimer's disease is also addressed, and promising perspectives for potential epigenetic drug treatment discussed.
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207
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Brien FD, Cloete SWP, Fogarty NM, Greeff JC, Hebart ML, Hiendleder S, Edwards JEH, Kelly JM, Kind KL, Kleemann DO, Plush KL, Miller DR. A review of the genetic and epigenetic factors affecting lamb survival. ANIMAL PRODUCTION SCIENCE 2014. [DOI: 10.1071/an13140] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Poor lamb survival pre-weaning is a major source of reproductive inefficiency in Australian sheep flocks. While nutrition and management options have been extensively researched and promoted to improve lamb survival, the present review focuses on the prospects for obtaining genetic gain and helps identify selection strategies for boosting such gains to improve overall reproductive efficiency in the Australian sheep industry. Estimated heritability for lamb survival using linear model analysis is low, although use of threshold models suggests that heritability could be higher, which, if true, could help explain the substantial genetic gains obtained in long-term selection experiments. Epigenetic mechanisms may hinder selection and quantitative trait-loci identification through confounding and/or masking genetic variances and co-variances. With sufficient information, these effects could be considered in genetic evaluations by identifying those components that are amenable to selection. Regarding indirect selection, finding effective criteria for improving lamb survival has proved elusive. Most measures of maternal behaviour, temperament and lambing difficulty researched are poorly correlated genetically with lamb survival. Of lamb behaviours and thermo-genic indicators studied, latency to bleat following handling by humans is moderately genetically correlated with lamb survival, as is neonatal rectal temperature. Industry application remains to be adequately explored for the more promising of these measures. Finally, in lieu of direct selection for lamb survival, there is merit in selecting for multiple-rearing ability or its equivalent, possibly with additional selection criteria for lamb survival and reproductive efficiency.
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208
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Urbanek-Olejnik K, Liszewska M, Winczura A, Kostka G. Changes of c-Myc and DNMT1 mRNA and protein levels in the rat livers induced by dibutyl phthalate treatment. Toxicol Ind Health 2013; 32:801-8. [DOI: 10.1177/0748233713512363] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
We investigated the relationship between dibutyl phthalate (DBP)-induced hypomethylation of the c-Myc promoter region (as evident in our early study) and the expression of c-Myc and DNMT1 genes (at messenger RNA (mRNA) and protein level) in the rat liver. Male Wistar rats received DBP in 1, 3, or 14 daily doses of 1800 mg kg−1 body weight. Levels of DNMT1, c-Myc mRNA, and proteins were detected using real-time polymerase chain reaction and Western blot analysis, respectively. Our findings indicate that DBP caused an increase in mRNA levels of c-Myc at all time points. The results showed that protein levels of c-Myc in rat liver also increased significantly by DBP treatment, which were more pronounced at last time point (after 14 doses). Furthermore, overexpression of DNMT1gene have been found after one dose of DBP, which was confirmed at the protein level by Western blot analysis. Reduced levels of DNMT1mRNA and proteins (3 and 14 doses) were coordinated with depletion DNA synthesis (reported previously). Based on our previous results and those presented here, the following conclusion could be drawn: (1) DBP exerted biological activity through epigenetic modulation of c-Myc gene expression; (2) it seems possible that DBP-induced active demethylation of c-Myc gene through mechanism(s) linked to generation of reactive oxygen species by activated c-Myc; and (3) control of DNA replication was not directly dependent on c-Myc transcriptional activity and we attribute this finding to DNMT1gene expression which was tightly coordinated with DNA synthesis.
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Affiliation(s)
- Katarzyna Urbanek-Olejnik
- Department of Toxicology and Risk Assessment, National Institute of Public Health-National Institute of Hygiene, Warsaw, Poland
| | - Monika Liszewska
- Department of Toxicology and Risk Assessment, National Institute of Public Health-National Institute of Hygiene, Warsaw, Poland
| | - Alicja Winczura
- Department of Molecular Biology, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Grażyna Kostka
- Department of Toxicology and Risk Assessment, National Institute of Public Health-National Institute of Hygiene, Warsaw, Poland
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209
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Lisanti S, Omar WAW, Tomaszewski B, De Prins S, Jacobs G, Koppen G, Mathers JC, Langie SAS. Comparison of methods for quantification of global DNA methylation in human cells and tissues. PLoS One 2013; 8:e79044. [PMID: 24260150 PMCID: PMC3832524 DOI: 10.1371/journal.pone.0079044] [Citation(s) in RCA: 121] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Accepted: 09/26/2013] [Indexed: 12/25/2022] Open
Abstract
DNA methylation is a key epigenetic modification which, in mammals, occurs mainly at CpG dinucleotides. Most of the CpG methylation in the genome is found in repetitive regions, rich in dormant transposons and endogenous retroviruses. Global DNA hypomethylation, which is a common feature of several conditions such as ageing and cancer, can cause the undesirable activation of dormant repeat elements and lead to altered expression of associated genes. DNA hypomethylation can cause genomic instability and may contribute to mutations and chromosomal recombinations. Various approaches for quantification of global DNA methylation are widely used. Several of these approaches measure a surrogate for total genomic methyl cytosine and there is uncertainty about the comparability of these methods. Here we have applied 3 different approaches (luminometric methylation assay, pyrosequencing of the methylation status of the Alu repeat element and of the LINE1 repeat element) for estimating global DNA methylation in the same human cell and tissue samples and have compared these estimates with the "gold standard" of methyl cytosine quantification by HPLC. Next to HPLC, the LINE1 approach shows the smallest variation between samples, followed by Alu. Pearson correlations and Bland-Altman analyses confirmed that global DNA methylation estimates obtained via the LINE1 approach corresponded best with HPLC-based measurements. Although, we did not find compelling evidence that the gold standard measurement by HPLC could be substituted with confidence by any of the surrogate assays for detecting global DNA methylation investigated here, the LINE1 assay seems likely to be an acceptable surrogate in many cases.
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Affiliation(s)
- Sofia Lisanti
- Human Nutrition Research Centre, Institute for Ageing and Health, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, United Kingdom
- Centre for Integrated Systems Biology of Ageing and Nutrition, Institute for Ageing and Health, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, United Kingdom
| | - Wan A. W. Omar
- Human Nutrition Research Centre, Institute for Ageing and Health, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, United Kingdom
- Advance Medical and Dental Institute, Universiti Sains Malaysia, Penang, Malaysia
| | - Bartłomiej Tomaszewski
- Human Nutrition Research Centre, Institute for Ageing and Health, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, United Kingdom
- Centre for Brain Ageing and Vitality, Institute for Ageing & Health, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, United Kingdom
| | - Sofie De Prins
- Environmental Risk and Health unit, Flemish Institute for Technological Research (VITO), Mol, Belgium
- Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Antwerp, Belgium
| | - Griet Jacobs
- Environmental Risk and Health unit, Flemish Institute for Technological Research (VITO), Mol, Belgium
| | - Gudrun Koppen
- Environmental Risk and Health unit, Flemish Institute for Technological Research (VITO), Mol, Belgium
| | - John C. Mathers
- Human Nutrition Research Centre, Institute for Ageing and Health, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, United Kingdom
- Centre for Integrated Systems Biology of Ageing and Nutrition, Institute for Ageing and Health, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, United Kingdom
- Centre for Brain Ageing and Vitality, Institute for Ageing & Health, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, United Kingdom
| | - Sabine A. S. Langie
- Human Nutrition Research Centre, Institute for Ageing and Health, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, United Kingdom
- Environmental Risk and Health unit, Flemish Institute for Technological Research (VITO), Mol, Belgium
- Centre for Brain Ageing and Vitality, Institute for Ageing & Health, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, United Kingdom
- * E-mail:
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210
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Sioulas AD, Vasilatou D, Pappa V, Dimitriadis G, Triantafyllou K. Epigenetics in gastrointestinal stromal tumors: clinical implications and potential therapeutic perspectives. Dig Dis Sci 2013; 58:3094-102. [PMID: 23873383 DOI: 10.1007/s10620-013-2785-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2013] [Accepted: 06/28/2013] [Indexed: 12/18/2022]
Abstract
Gastrointestinal stromal tumors (GIST) represent the most common mesenchymal neoplasms affecting the gastrointestinal tract. Activating mutations in either the KIT or PDGFRa gene are the principal oncogenic triggers with the former accounting for more than 80 % of cases. In the small subset of GIST that are wild type for both the aforementioned changes, other germline or somatic mutations have been identified. GIST exhibit a highly variable clinical behavior and the main prognostic determinants are tumor size, mitotic rate, and location. It is, however, strongly believed that, beyond classic genetics, additional epigenetic phenomena such as DNA hypomethylation and hypermethylation, microRNA alterations, and chromatin modifications underlie GIST tumorigenesis and influence the clinical course and response to standard treatment. This review aims to illuminate current advances in terms of epigenetics in GIST, as well as possible implications in prognosis and therapeutics.
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Affiliation(s)
- Athanasios D Sioulas
- 2nd Department of Internal Medicine and Research Unit, Attikon University General Hospital, Medical School, Athens University, Rimini 1, 12462, Haidari, Greece,
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211
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Jia W, Chen W, Kang J. The functions of microRNAs and long non-coding RNAs in embryonic and induced pluripotent stem cells. GENOMICS PROTEOMICS & BIOINFORMATICS 2013; 11:275-83. [PMID: 24096129 PMCID: PMC4357836 DOI: 10.1016/j.gpb.2013.09.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Revised: 09/02/2013] [Accepted: 09/03/2013] [Indexed: 12/19/2022]
Abstract
Embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) hold immense promise for regenerative medicine due to their abilities to self-renew and to differentiate into all cell types. This unique property is controlled by a complex interplay between transcriptional factors and epigenetic regulators. Recent research indicates that the epigenetic role of non-coding RNAs (ncRNAs) is an integral component of this regulatory network. This report will summarize findings that focus on two classes of regulatory ncRNAs, microRNAs (miRNAs) and long ncRNAs (lncRNAs), in the induction, maintenance and directed differentiation of ESCs and iPSCs. Manipulating these two important types of ncRNAs would be crucial to unlock the therapeutic and research potential of pluripotent stem cells.
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Affiliation(s)
- Wenwen Jia
- Clinical and Translational Research Center of Shanghai First Maternity and Infant Health Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Science and Technology, Tongji University, Shanghai 200092, China
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212
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Prickett AR, Barkas N, McCole RB, Hughes S, Amante SM, Schulz R, Oakey RJ. Genome-wide and parental allele-specific analysis of CTCF and cohesin DNA binding in mouse brain reveals a tissue-specific binding pattern and an association with imprinted differentially methylated regions. Genome Res 2013; 23:1624-35. [PMID: 23804403 PMCID: PMC3787260 DOI: 10.1101/gr.150136.112] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Accepted: 06/20/2013] [Indexed: 11/25/2022]
Abstract
DNA binding factors are essential for regulating gene expression. CTCF and cohesin are DNA binding factors with central roles in chromatin organization and gene expression. We determined the sites of CTCF and cohesin binding to DNA in mouse brain, genome wide and in an allele-specific manner with high read-depth ChIP-seq. By comparing our results with existing data for mouse liver and embryonic stem (ES) cells, we investigated the tissue specificity of CTCF binding sites. ES cells have fewer unique CTCF binding sites occupied than liver and brain, consistent with a ground-state pattern of CTCF binding that is elaborated during differentiation. CTCF binding sites without the canonical consensus motif were highly tissue specific. In brain, a third of CTCF and cohesin binding sites coincide, consistent with the potential for many interactions between cohesin and CTCF but also many instances of independent action. In the context of genomic imprinting, CTCF and/or cohesin bind to a majority but not all differentially methylated regions, with preferential binding to the unmethylated parental allele. Whether the parental allele-specific methylation was established in the parental germlines or post-fertilization in the embryo is not a determinant in CTCF or cohesin binding. These findings link CTCF and cohesin with the control regions of a subset of imprinted genes, supporting the notion that imprinting control is mechanistically diverse.
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Affiliation(s)
- Adam R. Prickett
- Department of Medical & Molecular Genetics, King's College London, Guy's Hospital, London, SE1 9RT, United Kingdom
| | - Nikolaos Barkas
- Department of Medical & Molecular Genetics, King's College London, Guy's Hospital, London, SE1 9RT, United Kingdom
| | - Ruth B. McCole
- Department of Medical & Molecular Genetics, King's College London, Guy's Hospital, London, SE1 9RT, United Kingdom
| | - Siobhan Hughes
- Department of Medical & Molecular Genetics, King's College London, Guy's Hospital, London, SE1 9RT, United Kingdom
| | - Samuele M. Amante
- Department of Medical & Molecular Genetics, King's College London, Guy's Hospital, London, SE1 9RT, United Kingdom
| | - Reiner Schulz
- Department of Medical & Molecular Genetics, King's College London, Guy's Hospital, London, SE1 9RT, United Kingdom
| | - Rebecca J. Oakey
- Department of Medical & Molecular Genetics, King's College London, Guy's Hospital, London, SE1 9RT, United Kingdom
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213
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Lee MR, Prasain N, Chae HD, Kim YJ, Mantel C, Yoder MC, Broxmeyer HE. Epigenetic regulation of NANOG by miR-302 cluster-MBD2 completes induced pluripotent stem cell reprogramming. Stem Cells 2013; 31:666-81. [PMID: 23255147 DOI: 10.1002/stem.1302] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2012] [Revised: 11/14/2012] [Accepted: 11/21/2012] [Indexed: 01/10/2023]
Abstract
While most somatic cells undergoing induced pluripotent stem (iPS) cell reprogramming with Yamanaka factors accumulate at stable partially reprogrammed stages, the molecular mechanisms required to achieve full reprogramming are unknown. MicroRNAs (miRNAs) fine-tune mRNA translation and are implicated in reprogramming, but miRNA functional targets critical for complete iPS cell reprogramming remain elusive. We identified methyl-DNA binding domain protein 2 (MBD2) as an epigenetic suppressor, blocking full reprogramming of somatic to iPS cells through direct binding to NANOG promoter elements preventing transcriptional activation. When we overexpressed miR-302 cluster we observed a significant increase in conversion of partial to fully reprogrammed iPS cells by suppressing MBD2 expression, thereby increasing NANOG expression. Thus, expression of exogenous miR-302 cluster (without miR-367) is efficient in attaining a fully reprogrammed iPS state in partially reprogrammed cells by relieving MBD2-mediated inhibition of NANOG expression. Our studies provide a direct molecular mechanism involved in generating complete human iPS cell reprogramming to study disease pathogenesis, drug screening, and for potential cell-based therapies.
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Affiliation(s)
- Man Ryul Lee
- Department of Microbiology and Immunology and Indiana University School of Medicine, Indianapolis, Indiana 46202-5181, USA
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214
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van den Elsen PJ, van Eggermond MCJA, Puentes F, van der Valk P, Baker D, Amor S. The epigenetics of multiple sclerosis and other related disorders. Mult Scler Relat Disord 2013; 3:163-75. [PMID: 25878004 DOI: 10.1016/j.msard.2013.08.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Revised: 08/19/2013] [Accepted: 08/30/2013] [Indexed: 02/05/2023]
Abstract
Multiple Sclerosis (MS) is a demyelinating disease characterized by chronic inflammation of the central nervous system (CNS) gray and white matter. Although the cause of MS is unknown, it is widely appreciated that innate and adaptive immune processes contribute to its pathogenesis. These include microglia/macrophage activation, pro-inflammatory T-cell (Th1) responses and humoral responses. Additionally, there is evidence indicating that MS has a neurodegenerative component since neuronal and axonal loss occurs even in the absence of overt inflammation. These aspects also form the rationale for clinical management of the disease. However, the currently available therapies to control the disease are only partially effective at best indicating that more effective therapeutic solutions are urgently needed. It is appreciated that in the immune-driven and neurodegenerative processes MS-specific deregulation of gene expressions and resulting protein dysfunction are thought to play a central role. These deviations in gene expression patterns contribute to the inflammatory response in the CNS, and to neuronal or axonal loss. Epigenetic mechanisms control transcription of most, if not all genes, in nucleated cells including cells of the CNS and in haematopoietic cells. MS-specific alterations in epigenetic regulation of gene expression may therefore lie at the heart of the deregulation of gene expression in MS. As such, epigenetic mechanisms most likely play an important role in disease pathogenesis. In this review we discuss a role for MS-specific deregulation of epigenetic features that control gene expression in the CNS and in the periphery. Furthermore, we discuss the application of small molecule inhibitors that target the epigenetic machinery to ameliorate disease in experimental animal models, indicating that such approaches may be applicable to MS patients.
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Affiliation(s)
- Peter J van den Elsen
- Department of Pathology, VU University Medical Center, Amsterdam, The Netherlands; Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, Leiden, The Netherlands.
| | - Marja C J A van Eggermond
- Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, Leiden, The Netherlands
| | - Fabiola Puentes
- Neuroscience and Trauma Centre, Blizard Institute, Barts and the London School of Medicine and Dentistry, QJ;Queen Mary University of London, London, United Kingdom
| | - Paul van der Valk
- Department of Pathology, VU University Medical Center, Amsterdam, The Netherlands
| | - David Baker
- Neuroscience and Trauma Centre, Blizard Institute, Barts and the London School of Medicine and Dentistry, QJ;Queen Mary University of London, London, United Kingdom
| | - Sandra Amor
- Department of Pathology, VU University Medical Center, Amsterdam, The Netherlands; Neuroscience and Trauma Centre, Blizard Institute, Barts and the London School of Medicine and Dentistry, QJ;Queen Mary University of London, London, United Kingdom
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215
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Xiang H, Li X, Dai F, Xu X, Tan A, Chen L, Zhang G, Ding Y, Li Q, Lian J, Willden A, Guo Q, Xia Q, Wang J, Wang W. Comparative methylomics between domesticated and wild silkworms implies possible epigenetic influences on silkworm domestication. BMC Genomics 2013; 14:646. [PMID: 24059350 PMCID: PMC3852238 DOI: 10.1186/1471-2164-14-646] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Accepted: 09/04/2013] [Indexed: 11/13/2022] Open
Abstract
Background In contrast to wild species, which have typically evolved phenotypes over long periods of natural selection, domesticates rapidly gained human-preferred agronomic traits in a relatively short-time frame via artificial selection. Under domesticated conditions, many traits can be observed that cannot only be due to environmental alteration. In the case of silkworms, aside from genetic divergence, whether epigenetic divergence played a role in domestication is an unanswered question. The silkworm is still an enigma in that it has two DNA methyltransferases (DNMT1 and DNMT2) but their functionality is unknown. Even in particular the functionality of the widely distributed DNMT1 remains unknown in insects in general. Results By embryonic RNA interference, we reveal that knockdown of silkworm Dnmt1 caused decreased hatchability, providing the first direct experimental evidence of functional significance of insect Dnmt1. In the light of this fact and those that DNA methylation is correlated with gene expression in silkworms and some agronomic traits in domesticated organisms are not stable, we comprehensively compare silk gland methylomes of 3 domesticated (Bombyx mori) and 4 wild (Bombyx mandarina) silkworms to identify differentially methylated genes between the two. We observed 2-fold more differentiated methylated cytosinces (mCs) in domesticated silkworms as compared to their wild counterparts, suggesting a trend of increasing DNA methylation during domestication. Further study of more domesticated and wild silkworms narrowed down the domesticates’ epimutations, and we were able to identify a number of differential genes. One such gene showing demethyaltion in domesticates correspondently displays lower gene expression, and more interestingly, has experienced selective sweep. A methylation-increased gene seems to result in higher expression in domesticates and the function of its Drosophila homolog was previously found to be essential for cell volume regulation, indicating a possible correlation with the enlargement of silk glands in domesticated silkworms. Conclusions Our results imply epigenetic influences at work during domestication, which gives insight into long time historical controversies regarding acquired inheritance.
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Affiliation(s)
- Hui Xiang
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, 32 East Jiaochang Road, Kunming, Yunnan Province 650223, China.
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216
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Lötsch J, Schneider G, Reker D, Parnham MJ, Schneider P, Geisslinger G, Doehring A. Common non-epigenetic drugs as epigenetic modulators. Trends Mol Med 2013; 19:742-53. [PMID: 24054876 DOI: 10.1016/j.molmed.2013.08.006] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2013] [Revised: 08/16/2013] [Accepted: 08/19/2013] [Indexed: 12/15/2022]
Abstract
Epigenetic effects are exerted by a variety of factors and evidence increases that common drugs such as opioids, cannabinoids, valproic acid, or cytostatics may induce alterations in DNA methylation patterns or histone conformations. These effects occur via chemical structural interactions with epigenetic enzymes, through interactions with DNA repair mechanisms. Computational predictions indicate that one-twentieth of all drugs might potentially interact with human histone deacetylase, which was prospectively experimentally verified for the compound with the highest predicted interaction probability. These epigenetic effects add to wanted and unwanted drug effects, contributing to mechanisms of drug resistance or disease-related and unrelated phenotypes. Because epigenetic changes might be transmitted to offspring, the need for reliable and cost-effective epigenetic screening tools becomes acute.
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Affiliation(s)
- Jörn Lötsch
- Institute of Clinical Pharmacology, Goethe University, Theodor-Stern-Kai 7, D-60590 Frankfurt am Main, Germany; Fraunhofer Institute of Molecular Biology and Applied Ecology - Project Group Translational Medicine and Pharmacology (IME-TMP), Theodor-Stern-Kai 7, D-60590 Frankfurt am Main, Germany.
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217
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Abstract
The Human Genome Project has transformed biology through its integrated big science approach to deciphering a reference human genome sequence along with the complete sequences of key model organisms. The project exemplifies the power, necessity and success of large, integrated, cross-disciplinary efforts - so-called 'big science' - directed towards complex major objectives. In this article, we discuss the ways in which this ambitious endeavor led to the development of novel technologies and analytical tools, and how it brought the expertise of engineers, computer scientists and mathematicians together with biologists. It established an open approach to data sharing and open-source software, thereby making the data resulting from the project accessible to all. The genome sequences of microbes, plants and animals have revolutionized many fields of science, including microbiology, virology, infectious disease and plant biology. Moreover, deeper knowledge of human sequence variation has begun to alter the practice of medicine. The Human Genome Project has inspired subsequent large-scale data acquisition initiatives such as the International HapMap Project, 1000 Genomes, and The Cancer Genome Atlas, as well as the recently announced Human Brain Project and the emerging Human Proteome Project.
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Affiliation(s)
- Leroy Hood
- Institute for Systems Biology, 401 Terry Ave N., Seattle, WA 98109, USA
| | - Lee Rowen
- Institute for Systems Biology, 401 Terry Ave N., Seattle, WA 98109, USA
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218
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Gomez D, Kessler K, Michel JB, Vranckx R. Modifications of Chromatin Dynamics Control Smad2 Pathway Activation in Aneurysmal Smooth Muscle Cells. Circ Res 2013; 113:881-90. [DOI: 10.1161/circresaha.113.301989] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Rationale
:
The activation of the Smad2 signaling pathway is thought to play an important role in human aneurysmal diseases as described by an important body of research. We previously showed that constitutive Smad2 activation is associated with Smad2 mRNA overexpression in aneurysmal vascular smooth muscle cells (VSMCs), which is dependent on epigenetic regulation of the
SMAD2
promoter involving histone modifications. However, the underlying molecular mechanisms controlling Smad2 overexpression are currently unknown.
Objective
:
The aim of the present study is to understand the mechanisms regulating the constitutive Smad2 overexpression in VSMCs by identification of the histone-modifying enzymes, transcription factors, and cofactors responsible for Smad2 promoter activation in aneurysmal disease.
Methods and Results
:
This study was performed on medial tissue extracts and primary cultures of VSMCs of human thoracic aneurysms (n=17) and normal thoracic aortas (n=10). Here, we demonstrate that the activation of
SMAD2
promoter is driven by the recruitment of a multipartner complex, including the transcription factor p53 and histone acetyltransferases. Remarkably, the transcriptional regulatory network of the
SMAD2
promoter is dramatically altered in human aneurysmal VSMCs in vitro and in situ with a switch from Myc-dependent repression of
SMAD2
in normal vessel to a p53-dependent activation of
SMAD2
in aneurysms. Furthermore, histone acetyltransferases p300 and P300/CBP-associated protein play a major role in
SMAD2
promoter activation by acting on histone acetylation, p53 recruitment, and acetylation.
Conclusions
:
These results provide evidence for a major role of p53 and the complex composed of p300 and p300/CBP-associated protein in Smad2 activation in human aneurysmal VSMCs.
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Affiliation(s)
- Delphine Gomez
- From the INSERM, U698, Paris, France (D.G., K.K., J.-B.M., R.V.); and Université Paris Diderot, Sorbonne Paris Cité, Paris, France (D.G., K.K., J.-B.M., R.V.)
| | - Ketty Kessler
- From the INSERM, U698, Paris, France (D.G., K.K., J.-B.M., R.V.); and Université Paris Diderot, Sorbonne Paris Cité, Paris, France (D.G., K.K., J.-B.M., R.V.)
| | - Jean-Baptiste Michel
- From the INSERM, U698, Paris, France (D.G., K.K., J.-B.M., R.V.); and Université Paris Diderot, Sorbonne Paris Cité, Paris, France (D.G., K.K., J.-B.M., R.V.)
| | - Roger Vranckx
- From the INSERM, U698, Paris, France (D.G., K.K., J.-B.M., R.V.); and Université Paris Diderot, Sorbonne Paris Cité, Paris, France (D.G., K.K., J.-B.M., R.V.)
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219
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Yadav M, Stephan S, Bluestone JA. Peripherally induced tregs - role in immune homeostasis and autoimmunity. Front Immunol 2013; 4:232. [PMID: 23966994 PMCID: PMC3736167 DOI: 10.3389/fimmu.2013.00232] [Citation(s) in RCA: 194] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Accepted: 07/22/2013] [Indexed: 12/16/2022] Open
Abstract
Thymically derived Foxp3(+) regulatory T cells (tTregs) constitute a unique T cell lineage that is essential for maintaining immune tolerance to self and immune homeostasis. However, Foxp3 can also be turned on in conventional T cells as a consequence of antigen exposure in the periphery, under both non-inflammatory and inflammatory conditions. These so-called peripheral Tregs (pTregs) participate in the control of immunity at sites of inflammation, especially at the mucosal surfaces. Although numerous studies have assessed in vitro generated Tregs (termed induced or iTregs), these cells most often do not recapitulate the functional or phenotypic characteristics of in vivo generated pTregs. Thus, there are still many unanswered questions regarding the T cell receptor (TCR) repertoire and function of pTregs as well as conditions under which they are generated in vivo, and the degree to which these characteristics identify specialized features of pTregs versus features that are shared with tTregs. In this review, we summarize the current state of our understanding of pTregs and their relationship to the tTreg subset. We describe the recent discovery of unique cell surface markers and transcription factors (including Neuropilin-1 and Helios) that can be used to distinguish tTreg and pTreg subsets in vivo. Additionally, we discuss how the improved ability to distinguish these subsets provided new insights into the biology of tTregs versus pTregs and suggested differences in their function and TCR repertoire, consistent with a unique role of pTregs in certain inflammatory settings. Finally, these recent advances will be used to speculate on the role of individual Treg subsets in both tolerance and autoimmunity.
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Affiliation(s)
- Mahesh Yadav
- Diabetes Center, University of California San Francisco , San Francisco, CA , USA
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220
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Milagro F, Mansego M, De Miguel C, Martínez J. Dietary factors, epigenetic modifications and obesity outcomes: Progresses and perspectives. Mol Aspects Med 2013; 34:782-812. [DOI: 10.1016/j.mam.2012.06.010] [Citation(s) in RCA: 209] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Accepted: 06/27/2012] [Indexed: 12/31/2022]
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221
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Seffer I, Nemeth Z, Hoffmann G, Matics R, Seffer AG, Koller A. Unexplored potentials of epigenetic mechanisms of plants and animals-theoretical considerations. GENETICS & EPIGENETICS 2013; 5:23-41. [PMID: 25512705 PMCID: PMC4222336 DOI: 10.4137/geg.s11752] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Morphological and functional changes of cells are important for adapting to environmental changes and associated with continuous regulation of gene expressions. Genes are regulated–in part–by epigenetic mechanisms resulting in alternating patterns of gene expressions throughout life. Epigenetic changes responding to the environmental and intercellular signals can turn on/off specific genes, but do not modify the DNA sequence. Most epigenetic mechanisms are evolutionary conserved in eukaryotic organisms, and several homologs of epigenetic factors are present in plants and animals. Moreover, in vitro studies suggest that the plant cytoplasm is able to induce a nuclear reassembly of the animal cell, whereas others suggest that the ooplasm is able to induce condensation of plant chromatin. Here, we provide an overview of the main epigenetic mechanisms regulating gene expression and discuss fundamental epigenetic mechanisms and factors functioning in both plants and animals. Finally, we hypothesize that animal genome can be reprogrammed by epigenetic factors from the plant protoplast.
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Affiliation(s)
| | - Zoltan Nemeth
- Seffer-Renner Medical Clinic, Budapest, Hungary. ; Department of Pathophysiology and Gerontology, Medical School, and Szentagothai Res Centre, University of Pecs, Pecs, Hungary
| | - Gyula Hoffmann
- Institute of Biology, Faculty of Sciences, University of Pecs, Pecs, Hungary
| | - Robert Matics
- Department of Pathophysiology and Gerontology, Medical School, and Szentagothai Res Centre, University of Pecs, Pecs, Hungary
| | - A Gergely Seffer
- Surgery Clinic, Medical School, University of Pecs, Pecs, Hungary
| | - Akos Koller
- Department of Pathophysiology and Gerontology, Medical School, and Szentagothai Res Centre, University of Pecs, Pecs, Hungary. ; Department of Physiology, New York Medical College, Valhalla NY, USA
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222
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Stringer JM, Barrand S, Western P. Fine-tuning evolution: germ-line epigenetics and inheritance. Reproduction 2013; 146:R37-48. [PMID: 23633622 DOI: 10.1530/rep-12-0526] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
In mice, epiblast cells found both the germ-line and somatic lineages in the developing embryo. These epiblast cells carry epigenetic information from both parents that is required for development and cell function in the fetus and during post-natal life. However, germ cells must establish an epigenetic program that supports totipotency and the configuration of parent-specific epigenetic states in the gametes. To achieve this, the epigenetic information inherited by the primordial germ cells at specification is erased and new epigenetic states are established during development of the male and female germ-lines. Errors in this process can lead to transmission of epimutations through the germ-line, which have the potential to affect development and disease in the parent's progeny. This review discusses epigenetic reprogramming in the germ-line and the transmission of epigenetic information to the following generation.
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Affiliation(s)
- Jessica M Stringer
- Germ Cell Development and Epigenetics Laboratory, Centre for Reproduction and Development, Monash Institute of Medical Research, 27-31 Wright Street, Clayton, Victoria 3168, Australia
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223
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Bian EB, Zhao B, Huang C, Wang H, Meng XM, Wu BM, Ma TT, Zhang L, Lv XW, Li J. New advances of DNA methylation in liver fibrosis, with special emphasis on the crosstalk between microRNAs and DNA methylation machinery. Cell Signal 2013; 25:1837-44. [PMID: 23707524 DOI: 10.1016/j.cellsig.2013.05.017] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Accepted: 05/07/2013] [Indexed: 12/17/2022]
Abstract
Epigenetics refers to the study of heritable changes in the pattern of gene expression that is controlled by a mechanism specifically not due to changes the primary DNA sequence. Well-known epigenetic mechanisms include DNA methylation, post-translational histone modifications and RNA-based mechanisms including those controlled by small non-coding RNAs (miRNAs). Recent studies have shown that epigenetic modifications orchestrate the hepatic stellate cell (HSC) activation and liver fibrosis. In this review we focus on the aberrant methylation of CpG island promoters of select genes is the prominent epigenetic mechanism to effectively silence gene transcription facilitating HSC activation and liver fibrosis. Furthermore, we also discuss epigenetic dysregulation of tumor-suppressor miRNA genes by promoter DNA methylation and the interaction of DNA methylation with miRNAs involved in the regulation of HSC activation and liver fibrosis. Recent advances in epigenetics alterations in the pathogenesis of liver fibrosis and their possible use as new therapeutic targets and biomarkers.
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Affiliation(s)
- Er-Bao Bian
- Institute for Liver Diseases of Anhui Medical University, Hefei 230032, Anhui Province, China
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224
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Abstract
Regulatory T (Treg) cells are a developmentally and functionally distinct T cell subpopulation that is engaged in sustaining immunological self-tolerance and homeostasis. The transcription factor Foxp3 plays a key role in Treg cell development and function. However, expression of Foxp3 alone is not sufficient for conferring and maintaining Treg cell function and phenotype. Complementing the insufficiency, Treg-cell-specific epigenetic changes are also critical in the process of Treg cell specification, in regulating its potential plasticity, and hence in establishing a stable lineage. Understanding how epigenetic alterations and Foxp3 expression coordinately control Treg-cell-specific gene regulation will enable better control of immune responses by targeting the generation and maintenance of Treg cells.
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Affiliation(s)
- Naganari Ohkura
- Department of Experimental Immunology, World Premier International Immunology Frontier Research Center, Osaka University, Suita 565-0871, Japan.
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225
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Hansberg-Pastor V, González-Arenas A, Peña-Ortiz MA, García-Gómez E, Rodríguez-Dorantes M, Camacho-Arroyo I. The role of DNA methylation and histone acetylation in the regulation of progesterone receptor isoforms expression in human astrocytoma cell lines. Steroids 2013; 78:500-7. [PMID: 23474171 DOI: 10.1016/j.steroids.2013.02.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Revised: 02/11/2013] [Accepted: 02/14/2013] [Indexed: 11/21/2022]
Abstract
Many progesterone (P4) effects are mediated by its intracellular receptor (PR), which has two isoforms, PR-A and PR-B, each of them with different function and regulation. Differential PR expression in cancer cells has been associated to a PR isoform-specific promoter methylation. In astrocytomas, the most frequent and aggressive brain tumors, PR isoforms expression is directly correlated to the tumor's evolution grade. However, there is no evidence of the role of epigenetic regulation of PR expression in astrocytomas. We evaluated the effect of the demethylating agent 5-aza-2'-deoxycytidine (5AzadC) and the histone deacetylase inhibitor trichostatin A (TSA) on PR expression in human astrocytoma cell lines U373 (grade III) and D54 (grade IV) by RT-PCR and Western blot. Total PR expression increased with 5 μM 5AzadC treatment, whereas PR-B expression increased with 5 and 10 μM 5AzadC treatment in U373 cells, but not in D54 cells. In U373 cells, PR-A protein content augmented with 10 μM 5AzadC treatment, while PR-B content increased with 5 and 10 μM 5AzadC. PR-B expression was not modified by the TSA concentrations that were used, and the combination with 5AzadC did not change the effects of the latter. The study of 5AzadC effects on the number of astrocytoma cells showed that P4 treatment increased the number of U373 cells, whereas 5AzadC and the combined treatment with P4 reduced it. Our results suggest that PR-B expression is regulated by methylation and not by histone acetylation in U373 cells, and that DNA demethylation reduced the number of U373 cells.
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Affiliation(s)
- Valeria Hansberg-Pastor
- Facultad de Química, Departamento de Biología, Universidad Nacional Autónoma de México, Av. Universidad 3000, Ciudad Universitaria, Coyoacán 04510, México, DF, Mexico
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226
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Maes K, Menu E, Van Valckenborgh E, Van Riet I, Vanderkerken K, De Bruyne E. Epigenetic modulating agents as a new therapeutic approach in multiple myeloma. Cancers (Basel) 2013; 5:430-61. [PMID: 24216985 PMCID: PMC3730337 DOI: 10.3390/cancers5020430] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Revised: 04/03/2013] [Accepted: 04/08/2013] [Indexed: 12/31/2022] Open
Abstract
Multiple myeloma (MM) is an incurable B-cell malignancy. Therefore, new targets and drugs are urgently needed to improve patient outcome. Epigenetic aberrations play a crucial role in development and progression in cancer, including MM. To target these aberrations, epigenetic modulating agents, such as DNA methyltransferase inhibitors (DNMTi) and histone deacetylase inhibitors (HDACi), are under intense investigation in solid and hematological cancers. A clinical benefit of the use of these agents as single agents and in combination regimens has been suggested based on numerous studies in pre-clinical tumor models, including MM models. The mechanisms of action are not yet fully understood but appear to involve a combination of true epigenetic changes and cytotoxic actions. In addition, the interactions with the BM niche are also affected by epigenetic modulating agents that will further determine the in vivo efficacy and thus patient outcome. A better understanding of the molecular events underlying the anti-tumor activity of the epigenetic drugs will lead to more rational drug combinations. This review focuses on the involvement of epigenetic changes in MM pathogenesis and how the use of DNMTi and HDACi affect the myeloma tumor itself and its interactions with the microenvironment.
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Affiliation(s)
- Ken Maes
- Department of Hematology and Immunology, Myeloma Center Brussels, Vrije Universiteit Brussel (VUB), Laarbeeklaan 103, 1090 Brussel, Belgium
| | - Eline Menu
- Department of Hematology and Immunology, Myeloma Center Brussels, Vrije Universiteit Brussel (VUB), Laarbeeklaan 103, 1090 Brussel, Belgium
| | - Els Van Valckenborgh
- Department of Hematology and Immunology, Myeloma Center Brussels, Vrije Universiteit Brussel (VUB), Laarbeeklaan 103, 1090 Brussel, Belgium
| | - Ivan Van Riet
- Stem Cell Laboratory, Department Clinical Hematology, Universitair Ziekenhuis Brussel (UZ Brussel), Laarbeeklaan 101, 1090 Brussel, Belgium
| | - Karin Vanderkerken
- Department of Hematology and Immunology, Myeloma Center Brussels, Vrije Universiteit Brussel (VUB), Laarbeeklaan 103, 1090 Brussel, Belgium
| | - Elke De Bruyne
- Department of Hematology and Immunology, Myeloma Center Brussels, Vrije Universiteit Brussel (VUB), Laarbeeklaan 103, 1090 Brussel, Belgium
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227
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Turner AP, Lones MA, Fuente LA, Stepney S, Caves LSD, Tyrrell AM. The incorporation of epigenetics in artificial gene regulatory networks. Biosystems 2013; 112:56-62. [PMID: 23499812 DOI: 10.1016/j.biosystems.2013.03.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Artificial gene regulatory networks are computational models that draw inspiration from biological networks of gene regulation. Since their inception they have been used to infer knowledge about gene regulation and as methods of computation. These computational models have been shown to possess properties typically found in the biological world, such as robustness and self organisation. Recently, it has become apparent that epigenetic mechanisms play an important role in gene regulation. This paper describes a new model, the Artificial Epigenetic Regulatory Network (AERN) which builds upon existing models by adding an epigenetic control layer. Our results demonstrate that AERNs are more adept at controlling multiple opposing trajectories when applied to a chaos control task within a conservative dynamical system, suggesting that AERNs are an interesting area for further investigation.
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Affiliation(s)
- Alexander P Turner
- Department of Electronics, University of York, Heslington, York YO10 5DD, UK.
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228
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Jenmalm MC, Duchén K. Timing of allergy-preventive and immunomodulatory dietary interventions - are prenatal, perinatal or postnatal strategies optimal? Clin Exp Allergy 2013; 43:273-8. [DOI: 10.1111/cea.12003] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- M. C. Jenmalm
- Division of Inflammation Medicine; Department of Clinical and Experimental Medicine; Linköping University; Linköping; Sweden
| | - K. Duchén
- Division of Paediatrics; Department of Clinical and Experimental Medicine; Linköping University; Linköping; Sweden
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229
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Bekdash RA, Zhang C, Sarkar DK. Gestational choline supplementation normalized fetal alcohol-induced alterations in histone modifications, DNA methylation, and proopiomelanocortin (POMC) gene expression in β-endorphin-producing POMC neurons of the hypothalamus. Alcohol Clin Exp Res 2013; 37:1133-42. [PMID: 23413810 DOI: 10.1111/acer.12082] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2012] [Accepted: 11/08/2012] [Indexed: 02/03/2023]
Abstract
BACKGROUND Prenatal exposure to ethanol (EtOH) reduces the expression of hypothalamic proopiomelanocortin (POMC) gene, known to control various physiological functions including the organismal stress response. In this study, we determined whether the changes in POMC neuronal functions are associated with altered expressions of histone-modifying and DNA-methylating enzymes in POMC-producing neurons, because these enzymes are known to be involved in regulation of gene expression. In addition, we tested whether gestational choline supplementation prevents the adverse effects of EtOH on these neurons. METHODS Pregnant rat dams were fed with alcohol-containing liquid diet or control diet during gestational days 7 and 21 with or without choline, and their male offspring rats were used during the adult period. Using double-immunohistochemistry, real-time reverse transcription polymerase chain reaction (RT-PCR) and methylation-specific RT-PCR, we determined protein and mRNA levels of histone-modifying and DNA-methylating enzymes and the changes in POMC gene methylation and expression in the hypothalamus of adult male offspring rats. Additionally, we measured the basal- and lipopolysaccharide (LPS)-induced corticosterone levels in plasma by enzyme-linked immunosorbent assay. RESULTS Prenatal EtOH treatment suppressed hypothalamic levels of protein and mRNA of histone activation marks (H3K4me3, Set7/9, acetylated H3K9, phosphorylated H3S10), and increased the repressive marks (H3K9me2, G9a, Setdb1), DNA-methylating enzyme (Dnmt1), and the methyl-CpG-binding protein (MeCP2). The treatment also elevated the level of POMC gene methylation, while it reduced levels of POMC mRNA and β-EP and elevated corticosterone response to LPS. Gestational choline normalized the EtOH-altered protein and the mRNA levels of H3K4me3, Set7/9, H3K9me2, G9a, Setdb1, Dnmt1, and MeCP2. It also normalizes the changes in POMC gene methylation and gene expression, β-EP production, and the corticosterone response to LPS. CONCLUSIONS These data suggest that prenatal EtOH modulates histone and DNA methylation in POMC neurons that may be resulting in hypermethylation of POMC gene and reduction in POMC gene expression. Gestational choline supplementation prevents the adverse effects of EtOH on these neurons.
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Affiliation(s)
- Rola A Bekdash
- Endocrine Program, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901, USA
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230
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Pogribny IP, Rusyn I. Environmental toxicants, epigenetics, and cancer. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 754:215-32. [PMID: 22956504 PMCID: PMC4281087 DOI: 10.1007/978-1-4419-9967-2_11] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Tumorigenesis, a complex and multifactorial progressive process of transformation of normal cells into malignant cells, is characterized by the accumulation of multiple cancer-specific heritable phenotypes triggered by the mutational and/or non-mutational (i.e., epigenetic) events. Accumulating evidence suggests that environmental and occupational exposures to natural substances, as well as man-made chemical and physical agents, play a causative role in human cancer. In a broad sense, carcinogenesis may be induced through either genotoxic or non-genotoxic mechanisms; however, both genotoxic and non-genotoxic carcinogens also cause prominent epigenetic changes. This review presents current evidence of the epigenetic alterations induced by various chemical carcinogens, including arsenic, 1,3-butadine, and pharmaceutical and biological agents, and highlights the potential for epigenetic changes to serve as markers for carcinogen exposure and cancer risk assessment.
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Affiliation(s)
- Igor P. Pogribny
- Division of Biochemical Toxicology, National Center for Toxicological Research, Jefferson, AR 72079, USA
| | - Ivan Rusyn
- Department of Environmental Sciences & Engineering, University of North Carolina, Chapel Hill, NC 27599, USA
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231
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Abstract
The functional impact of aberrant DNA methylation and the widespread alterations in DNA methylation in cancer development have led to the development of a variety of methods to characterize the DNA methylation patterns. This chapter critiques and describes the major approaches to analyzing DNA methylation.
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Li KK, Luo C, Wang D, Jiang H, Zheng YG. Chemical and biochemical approaches in the study of histone methylation and demethylation. Med Res Rev 2012; 32:815-67. [PMID: 22777714 DOI: 10.1002/mrr.20228] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Histone methylation represents one of the most critical epigenetic events in DNA function regulation in eukaryotic organisms. Classic molecular biology and genetics tools provide significant knowledge about mechanisms and physiological roles of histone methyltransferases and demethylases in various cellular processes. In addition to this stream line, development and application of chemistry and chemistry-related techniques are increasingly involved in biological study, and offer information otherwise difficult to obtain by standard molecular biology methods. Herein, we review recent achievements and progress in developing and applying chemical and biochemical approaches in the study of histone methylation, including chromatin immunoprecipitation, chemical ligation, mass spectrometry, biochemical methylation and demethylation assays, and inhibitor development. These technological advances allow histone methylation to be studied from genome-wide level to molecular and atomic levels. With ChIP technology, information can be obtained about precise mapping of histone methylation patterns at specific promoters, genes, or other genomic regions. MS is particularly useful in detecting and analyzing methylation marks in histone and nonhistone protein substrates. Chemical approaches that permit site-specific incorporation of methyl groups into histone proteins greatly facilitate the investigation of biological impacts of methylation at individual modification sites. Discovery and design of selective organic inhibitors of histone methyltransferases and demethylases provide chemical probes to interrogate methylation-mediated cellular pathways. Overall, these chemistry-related technological advances have greatly improved our understanding of the biological functions of histone methylation in normal physiology and diseased states, and also are of great potential to translate basic epigenetics research into diagnostic and therapeutic applications in the clinic.
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Affiliation(s)
- Keqin Kathy Li
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Rui Jin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
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233
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T cell receptor stimulation-induced epigenetic changes and Foxp3 expression are independent and complementary events required for Treg cell development. Immunity 2012; 37:785-99. [PMID: 23123060 DOI: 10.1016/j.immuni.2012.09.010] [Citation(s) in RCA: 558] [Impact Index Per Article: 46.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Accepted: 09/07/2012] [Indexed: 12/13/2022]
Abstract
The transcription factor Foxp3 is essential for the development of regulatory T (Treg) cells, yet its expression is insufficient for establishing the Treg cell lineage. Here we showed that Treg cell development was achieved by the combination of two independent processes, i.e., the expression of Foxp3 and the establishment of Treg cell-specific CpG hypomethylation pattern. Both events were induced by T cell receptor stimulation. The Treg cell-type CpG hypomethylation began in the thymus and continued to proceed in the periphery and could be fully established without Foxp3. The hypomethylation was required for Foxp3(+) T cells to acquire Treg cell-type gene expression, lineage stability, and full suppressive activity. Thus, those T cells in which the two events have concurrently occurred are developmentally set into the Treg cell lineage. This model explains how Treg cell fate and plasticity is controlled and can be exploited to generate functionally stable Treg cells.
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234
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Grazul-Bilska AT, Johnson ML, Borowicz PP, Baranko L, Redmer DA, Reynolds LP. Placental development during early pregnancy in sheep: effects of embryo origin on fetal and placental growth and global methylation. Theriogenology 2012; 79:94-102. [PMID: 23117132 DOI: 10.1016/j.theriogenology.2012.09.013] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Revised: 09/24/2012] [Accepted: 09/24/2012] [Indexed: 01/21/2023]
Abstract
The origin of embryos including those created through assisted reproductive technologies might have profound effects on placental and fetal development, possibly leading to compromised pregnancies associated with poor placental development. To determine the effects of embryo origin on fetal size, and maternal and fetal placental cellular proliferation and global methylation, pregnancies were achieved through natural mating (NAT), or transfer of embryos generated through in vivo (NAT-ET), IVF, or in vitro activation (IVA). On Day 22 of pregnancy, fetuses were measured and placental tissues were collected to immunologically detect Ki67 (a marker of proliferating cells) and 5-methyl cytosine followed by image analysis, and determine mRNA expression for three DNA methyltransferases. Fetal length and labeling index (proportion of proliferating cells) in maternal caruncles (maternal placenta) and fetal membranes (fetal placenta) were less (P < 0.001) in NAT-ET, IVF, and IVA than in NAT. In fetal membranes, expression of 5-methyl cytosine was greater (P < 0.02) in IVF and IVA than in NAT. In maternal caruncles, mRNA expression for DNMT1 was greater (P < 0.01) in IVA compared with the other groups, but DNMT3A expression was less (P < 0.04) in NAT-ET and IVA than in NAT. In fetal membranes, expression of mRNA for DNMT3A was greater (P < 0.01) in IVA compared with the other groups, and was similar in NAT, NAT-ET, and IVF groups. Thus, embryo origin might have specific effects on growth and function of ovine uteroplacental and fetal tissues through regulation of tissue growth, DNA methylation, and likely other mechanisms. These data provide a foundation for determining expression of specific factors regulating placental and fetal tissue growth and function in normal and compromised pregnancies, including those achieved with assisted reproductive technologies.
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Affiliation(s)
- Anna T Grazul-Bilska
- Department of Animal Sciences, Center for Nutrition and Pregnancy, North Dakota State University, Fargo, North Dakota, USA.
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235
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Abstract
AbstractThe science of genetics is undergoing a paradigm shift. Recent discoveries, including the activity of retrotransposons, the extent of copy number variations, somatic and chromosomal mosaicism, and the nature of the epigenome as a regulator of DNA expressivity, are challenging a series of dogmas concerning the nature of the genome and the relationship between genotype and phenotype. According to three widely held dogmas, DNA is the unchanging template of heredity, is identical in all the cells and tissues of the body, and is the sole agent of inheritance. Rather than being an unchanging template, DNA appears subject to a good deal of environmentally induced change. Instead of identical DNA in all the cells of the body, somatic mosaicism appears to be the normal human condition. And DNA can no longer be considered the sole agent of inheritance. We now know that the epigenome, which regulates gene expressivity, can be inherited via the germline. These developments are particularly significant for behavior genetics for at least three reasons: First, epigenetic regulation, DNA variability, and somatic mosaicism appear to be particularly prevalent in the human brain and probably are involved in much of human behavior; second, they have important implications for the validity of heritability and gene association studies, the methodologies that largely define the discipline of behavior genetics; and third, they appear to play a critical role in development during the perinatal period and, in particular, in enabling phenotypic plasticity in offspring. I examine one of the central claims to emerge from the use of heritability studies in the behavioral sciences, the principle of minimal shared maternal effects, in light of the growing awareness that the maternal perinatal environment is a critical venue for the exercise of adaptive phenotypic plasticity. This consideration has important implications for both developmental and evolutionary biology.
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236
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Benetatos L, Voulgaris E, Vartholomatos G, Hatzimichael E. Non-coding RNAs and EZH2 interactions in cancer: long and short tales from the transcriptome. Int J Cancer 2012; 133:267-74. [PMID: 23001607 DOI: 10.1002/ijc.27859] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Accepted: 08/14/2012] [Indexed: 12/12/2022]
Abstract
A large amount of data indicates that non-coding RNAs represent more than the "dark matter" of the genome. Both microRNAs and long non-coding RNAs are involved in several fundamental biologic processes, and their deregulation may lead in oncogenesis. Interacting with the Polycomb-repressive complex 2 subunit EZH2, they could affect the expression of protein-coding genes and form feedback networks and autoregulatory loops. They can also form networks with upstream and downstream important factors, in which EZH2 represent the stabilizing factor of the pathway. As such non-coding RNAs affect the epigenetic modifications leading to malignant transformation.
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237
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Vialou V, Feng J, Robison AJ, Nestler EJ. Epigenetic mechanisms of depression and antidepressant action. Annu Rev Pharmacol Toxicol 2012; 53:59-87. [PMID: 23020296 DOI: 10.1146/annurev-pharmtox-010611-134540] [Citation(s) in RCA: 184] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Epigenetic mechanisms, which control chromatin structure and function, mediate changes in gene expression that occur in response to diverse stimuli. Recent research has established that environmental events and behavioral experience induce epigenetic changes at particular gene loci and that these changes help shape neuronal plasticity and function and hence behavior. Some of these changes can be stable and can even persist for a lifetime. Increasing evidence supports the hypothesis that aberrations in chromatin remodeling and subsequent effects on gene expression within limbic brain regions contribute to the pathogenesis of depression and other stress-related disorders such as post-traumatic stress disorder and other anxiety syndromes. Likewise, the gradually developing but persistent therapeutic effects of antidepressant medications may be achieved in part via epigenetic mechanisms. This review discusses recent advances in our understanding of the epigenetic regulation of stress-related disorders and focuses on three distinct aspects of stress-induced epigenetic pathology: the effects of stress and antidepressant treatment during adulthood, the lifelong effects of early-life stress on subsequent stress vulnerability, and the possible transgenerational transmission of stress-induced abnormalities.
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Affiliation(s)
- Vincent Vialou
- Fishberg Department of Neuroscience and Friedman Brain Institute, Mount Sinai School of Medicine, New York, New York 10029, USA
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238
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Mazzio EA, Soliman KFA. Basic concepts of epigenetics: impact of environmental signals on gene expression. Epigenetics 2012; 7:119-30. [PMID: 22395460 DOI: 10.4161/epi.7.2.18764] [Citation(s) in RCA: 151] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Through epigenetic modifications, specific long-term phenotypic consequences can arise from environmental influence on slowly evolving genomic DNA. Heritable epigenetic information regulates nucleosomal arrangement around DNA and determines patterns of gene silencing or active transcription. One of the greatest challenges in the study of epigenetics as it relates to disease is the enormous diversity of proteins, histone modifications and DNA methylation patterns associated with each unique maladaptive phenotype. This is further complicated by a limitless combination of environmental cues that could alter the epigenome of specific cell types, tissues, organs and systems. In addition, complexities arise from the interpretation of studies describing analogous but not identical processes in flies, plants, worms, yeast, ciliated protozoans, tumor cells and mammals. This review integrates fundamental basic concepts of epigenetics with specific focus on how the epigenetic machinery interacts and operates in continuity to silence or activate gene expression. Topics covered include the connection between DNA methylation, methyl-CpG-binding proteins, transcriptional repression complexes, histone residues, histone modifications that mediate gene repression or relaxation, histone core variant stability, H1 histone linker flexibility, FACT complex, nucleosomal remodeling complexes, HP1 and nuclear lamins.
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Affiliation(s)
- Elizabeth A Mazzio
- College of Pharmacy and Pharmaceutical Sciences, Florida A & M University, Tallahassee, FL USA
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239
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Qi J, Dmochowski JM, Banes AN, Tsuzaki M, Bynum D, Patterson M, Creighton A, Gomez S, Tech K, Cederlund A, Banes AJ. Differential expression and cellular localization of novel isoforms of the tendon biomarker tenomodulin. J Appl Physiol (1985) 2012; 113:861-71. [DOI: 10.1152/japplphysiol.00198.2012] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Tenomodulin (Tnmd, also called Tendin) is classified as a type II transmembrane glycoprotein and is highly expressed in developing as well as in mature tendons. Along with scleraxis (scx), Tnmd is a candidate marker gene for tenocytes. Its function is unknown, but it has been reported to have anti-angiogenic properties. Results in a knockout mouse model did not substantiate that claim. It has homology to chondromodulin-I. Single nucleotide polymorphisms of TNMD have been associated with obesity, macular degeneration, and Alzheimer's disease in patients. In the present study, three Tnmd isoforms with deduced molecular weights of 20.3 (isoform II), 25.4 (isoform III), and 37.1 (isoform I) kDa were proposed and verified by Western blot from cells with green fluorescent protein-linked, overexpressed constructs, tissue, and by qPCR of isoforms from human tissues and cultured cells. Overexpression of each Tnmd isoform followed by immunofluorescence imaging showed that isoforms I and II had perinuclear localization while isoform III was cytoplasmic. Results of qPCR demonstrated differential expression of each Tnmd isoform in patient's specimens taken from flexor carpi radialis, biceps brachii, and flexor digitorum profundus tendons. Knockdown of Tnmd increased the expression of both scleraxis (scx) and myostatin, indicating a potential negative feedback loop between Tnmd and its regulators. Knockdown of all Tnmd isoforms simultaneously also reduced tenocyte proliferation. I-TASSER protein three-dimensional conformation modeling predictions indicated each Tnmd isoform had different structures and potential functions: isoform 1, modeled as a cytosine methyltransferase; isoform 2, a SUMO-1-like SENP-1 protease; and isoform 3, an α-syntrophin, plextrin homology domain scaffolding protein. Further functional studies with each Tnmd isoform may help us to better understand regulation of tenocyte proliferation, tendon development, response to injury and strain, as well as mechanisms in tendinoses. These results may indicate novel therapeutic targets in specific tenomodulin isoforms as well as treatments for tendon diseases.
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Affiliation(s)
- J. Qi
- University of North Carolina, Chapel Hill, North Carolina
- Flexcell International, Hillsborough, North Carolina
| | | | - A. N. Banes
- Flexcell International, Hillsborough, North Carolina
- North Carolina State University, Raleigh, North Carolina; and
| | - M. Tsuzaki
- Flexcell International, Hillsborough, North Carolina
| | - D. Bynum
- University of North Carolina, Chapel Hill, North Carolina
| | - M. Patterson
- University of North Carolina, Chapel Hill, North Carolina
| | - A. Creighton
- University of North Carolina, Chapel Hill, North Carolina
| | | | - K. Tech
- University of North Carolina, Chapel Hill, North Carolina
| | | | - A. J. Banes
- University of North Carolina, Chapel Hill, North Carolina
- Flexcell International, Hillsborough, North Carolina
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240
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Nagy C, Turecki G. Sensitive periods in epigenetics: bringing us closer to complex behavioral phenotypes. Epigenomics 2012; 4:445-57. [PMID: 22920183 PMCID: PMC5293543 DOI: 10.2217/epi.12.37] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Genetic studies have attempted to elucidate causal mechanisms for the development of complex disease, but genome-wide associations have been largely unsuccessful in establishing these links. As an alternative link between genes and disease, recent efforts have focused on mechanisms that alter the function of genes without altering the underlying DNA sequence. Known as epigenetic mechanisms, these include DNA methylation, chromatin conformational changes through histone modifications, ncRNAs and, most recently, 5-hydroxymethylcytosine. Although DNA methylation is involved in normal development, aging and gene regulation, altered methylation patterns have been associated with disease. It is generally believed that early life constitutes a period during which there is increased sensitivity to the regulatory effects of epigenetic mechanisms. The purpose of this review is to outline the contribution of epigenetic mechanisms to genomic function, particularly in the development of complex behavioral phenotypes, focusing on the sensitive periods.
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Affiliation(s)
- Corina Nagy
- McGill Group for Suicide Studies, Douglas Hospital University Institute, 6875 Lasalle boul, Montreal, QC, Canada
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243
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Clenbuterol upregulates histone demethylase JHDM2a via the β2-adrenoceptor/cAMP/PKA/p-CREB signaling pathway. Cell Signal 2012; 24:2297-306. [PMID: 22820505 DOI: 10.1016/j.cellsig.2012.07.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Revised: 06/20/2012] [Accepted: 07/16/2012] [Indexed: 01/19/2023]
Abstract
BACKGROUND β(2)-Adrenergic receptor (β(2)-AR) signaling activated by the agonist clenbuterol is important in the metabolism of muscle and adipose cells. Additionally, the significant role of histone demethylase JHDM2a in regulating metabolic gene expression was also recently demonstrated in Jhdm2a(-/-) mice. To elucidate the molecular mechanism involved in clenbuterol-induced adipocyte reduction from an epigenetic perspective, this study focused on cAMP-responsive element binding protein (CREB) to determine whether JHDM2a is regulated by the β(2)-AR/cAMP/protein kinase A (PKA) signaling pathway. RESULTS In porcine tissues treated with clenbuterol, JHDM2a expression was upregulated, and in porcine cells, expression of exogenous CREB led to increased JHDM2a expression. In addition, changes in JHDM2a expression were coincident with variations in the phosphorylation of CREB and p-CREB/CBP interaction in porcine and human cells treated with drugs known to modify the β(2)-AR/cAMP/PKA pathway. Finally, binding assays demonstrated that CREB regulated JHDM2a by binding directly to the CRE site nearest to the transcription start site. CONCLUSION Our results reveal that clenbuterol activates the β(2)-AR signaling pathway upstream of JHDM2a and that CREB acts as an intermediate link regulated by cAMP-PKA to induce activity of the JHDM2a promoter. These findings suggest that clenbuterol decreases adipose cell size and increases muscle fiber size in porcine tissues by virtue of JHDM2a-mediated demethylation, which regulates downstream metabolic and related genes.
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244
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Napoli C, Crudele V, Soricelli A, Al-Omran M, Vitale N, Infante T, Mancini FP. Primary prevention of atherosclerosis: a clinical challenge for the reversal of epigenetic mechanisms? Circulation 2012; 125:2363-73. [PMID: 22586291 DOI: 10.1161/circulationaha.111.085787] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Claudio Napoli
- Department of General Pathology, Excellence Research Centre on Cardiovascular Diseases, 1st School of Medicine, Second University of Naples, Naples, Italy.
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245
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Lisanti S, von Zglinicki T, Mathers JC. Standardization and quality controls for the methylated DNA immunoprecipitation technique. Epigenetics 2012; 7:615-25. [PMID: 22507898 DOI: 10.4161/epi.20028] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
MeDIP (Methylated DNA Immunoprecipitation) is a relatively recent technique aimed to enrich the methylated fraction of DNA with an antibody directed against 5-methyl-cytosine. MeDIP processed samples are suitable for investigation of the methylation status of specific genomic loci and for performing genome-wide screening when hybridized to DNA methylation microarrays or analyzed by deep sequencing. Here, we describe a standardization protocol and quality controls to assess the specificity, reproducibility and efficiency of the MeDIP procedure. These may have utility when comparing results between samples and experiments within laboratories and between laboratories.
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Affiliation(s)
- Sofia Lisanti
- Centre for Integrated Systems Biology of Aging and Nutrition; Institute for Aging and Health; Newcastle University; Newcastle upon Tyne, UK.
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246
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Wong TS, Gao W, Li ZH, Chan JYW, Ho WK. Epigenetic dysregulation in laryngeal squamous cell carcinoma. JOURNAL OF ONCOLOGY 2012; 2012:739461. [PMID: 22645613 PMCID: PMC3356733 DOI: 10.1155/2012/739461] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/09/2011] [Revised: 02/16/2012] [Accepted: 02/16/2012] [Indexed: 12/17/2022]
Abstract
Laryngeal carcinoma is a common head and neck cancer with poor prognosis. Patients with laryngeal carcinoma usually present late leading to the reduced treatment efficacy and high rate of recurrence. Despite the advance in the use of molecular markers for monitoring human cancers in the past decades, there are still no reliable markers for use to screen laryngeal carcinoma and follow the patients after treatment. Epigenetics emerged as an important field in understanding the biology of the human malignancies. Epigenetic alterations refer to the dysregulation of gene, which do not involve the alterations of the DNA sequence. Major epigenetic changes including methylation imbalance, histone modification, and small RNA dysregulation could play a role in the development of human malignancies. Global epigenetic change is now regarded as a molecular signature of cancer. The characteristics and behavior of a cancer could be predicted based on the specific epigenetic pattern. We here provide a review on the understanding of epigenetic dysregulation in laryngeal carcinoma. Further knowledge on the initiation and progression of laryngeal carcinoma at epigenetic level could promote the translation of the knowledge to clinical use.
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Affiliation(s)
- Thian-Sze Wong
- Department of Surgery, Queen Mary Hospital, The University of Hong Kong, 102 Pokfulam Road, Hong Kong
| | - Wei Gao
- Department of Surgery, Queen Mary Hospital, The University of Hong Kong, 102 Pokfulam Road, Hong Kong
| | - Zeng-Hong Li
- Department of Surgery, Queen Mary Hospital, The University of Hong Kong, 102 Pokfulam Road, Hong Kong
| | - Jimmy Yu-Wai Chan
- Department of Surgery, Queen Mary Hospital, The University of Hong Kong, 102 Pokfulam Road, Hong Kong
| | - Wai-Kuen Ho
- Department of Surgery, Queen Mary Hospital, The University of Hong Kong, 102 Pokfulam Road, Hong Kong
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247
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Jenmalm MC. Should more be done during pregnancy to reduce allergies in children? ACTA ACUST UNITED AC 2012. [DOI: 10.2217/cpr.12.14] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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248
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Goerlich VC, Nätt D, Elfwing M, Macdonald B, Jensen P. Transgenerational effects of early experience on behavioral, hormonal and gene expression responses to acute stress in the precocial chicken. Horm Behav 2012; 61:711-8. [PMID: 22465454 DOI: 10.1016/j.yhbeh.2012.03.006] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2011] [Revised: 03/13/2012] [Accepted: 03/15/2012] [Indexed: 12/18/2022]
Abstract
Stress during early life can profoundly influence an individual's phenotype. Effects can manifest in the short-term as well as later in life and even in subsequent generations. Transgenerational effects of stress are potentially mediated via modulation of the hypothalamic-pituitary-adrenal axis (HPA) as well as epigenetic mechanisms causing heritable changes in gene expression. To investigate these pathways we subjected domestic chicken (Gallus gallus) to intermittent social isolation for the first three weeks of life. The early life stress resulted in a dampened corticosterone response to restraint stress in affected birds and in their male offspring. Stress-specific genes, such as early growth response 1 (EGR1) and corticotropin releasing hormone receptor 1 (CRHR1), were upregulated immediately after restraint stress, but not under baseline conditions. Treatment differences in gene expression were also correlated across generations which indicate transgenerational epigenetic inheritance. In an associative learning test early stressed birds made more correct choices suggesting a higher coping ability in stressful situations. This study is the first to show transgenerational effects of early life stress in a precocial species by combining behavioral, endocrinological, and transcriptomic measurements.
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MESH Headings
- Algorithms
- Animals
- Animals, Domestic
- Behavior, Animal/physiology
- Brain/metabolism
- Chickens/genetics
- Chickens/physiology
- Cohort Effect
- Female
- Gene Expression Regulation/physiology
- Male
- Models, Biological
- Physical Conditioning, Animal/methods
- Physical Conditioning, Animal/psychology
- Restraint, Physical/physiology
- Restraint, Physical/psychology
- Stress, Psychological/epidemiology
- Stress, Psychological/genetics
- Stress, Psychological/physiopathology
- Time Factors
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Affiliation(s)
- Vivian C Goerlich
- IFM Biology, Division of Zoology, Avian Behavioural Genomics and Physiology Group, Linköping University, Sweden
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249
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Ehringer MA. Connecting ncRNA Cigarette Smoking Studies with Tobacco Use Behaviors and Health Outcomes. Front Genet 2012; 3:49. [PMID: 22679449 PMCID: PMC3366720 DOI: 10.3389/fgene.2012.00049] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2012] [Accepted: 03/20/2012] [Indexed: 11/13/2022] Open
Affiliation(s)
- Marissa A Ehringer
- Institute for Behavioral Genetics, Department of Integrative Physiology, University of Colorado Boulder, CO, USA
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250
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Abstract
Cancer initiation and progression is controlled by both genetic and epigenetic events. The complexity of carcinogenesis cannot be accounted for by genetic alterations alone but also involves epigenetic changes. Epigenetics refers to the study of mechanisms that alter gene expression without altering the primary DNA sequence. Epigenetic mechanisms are heritable and reversible, and include changes in DNA methylation, histone modifications and small noncoding microRNAs (miRNA). Disruption of epigenetic processes can lead to altered gene function and malignant cellular transformation. Aberrant epigenetic modifications probably occur at a very early stage in neoplastic development, and they are widely described as essential players in cancer progression. Recent advances in epigenetics offer a better understanding of the underlying mechanism(s) of carcinogenesis and provide insight into the discovery of putative cancer biomarkers for early detection, disease monitoring, prognosis, and risk assessment. In this review, we summarize the current literature on epigenetic changes causing genetic alterations that are thought to contribute to cancer, and discuss the potential impact of epigenetics future research.
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Affiliation(s)
- R Kanwal
- Department of Urology, Case Western Reserve University, Case Comprehensive Cancer Center, 10900 Euclid Avenue, Cleveland, Ohio 44106, USA
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