101
|
Epigenetic Regulation of the Non-Coding Genome: Opportunities for Immuno-Oncology. EPIGENOMES 2020; 4:epigenomes4030022. [PMID: 34968293 PMCID: PMC8594693 DOI: 10.3390/epigenomes4030022] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Revised: 09/06/2020] [Accepted: 09/08/2020] [Indexed: 12/20/2022] Open
Abstract
The contribution of the non-coding genome to disease and its therapeutic potential have been largely unexplored. Recently, several epigenetic drugs developed for cancer treatment have been described to mediate therapeutic effects through the reactivation of the expression of transposable elements in cancer cells. This event activates innate immunity-related pathways and promotes the generation of neoantigens in tumor cells, improving the efficacy of immunotherapeutic treatments. This review focuses on the regulation of transposable elements by epigenetic inhibitors and its implications for immuno-oncology.
Collapse
|
102
|
Aberrant Methylation of LINE-1 Transposable Elements: A Search for Cancer Biomarkers. Cells 2020; 9:cells9092017. [PMID: 32887319 PMCID: PMC7563416 DOI: 10.3390/cells9092017] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 08/26/2020] [Accepted: 08/31/2020] [Indexed: 02/07/2023] Open
Abstract
Cancer remains one of the main causes of human mortality despite significant progress in its diagnostics and therapy achieved in the past decade. Massive hypomethylation of retrotransposons, in particular LINE-1, is considered a hallmark of most malignant transformations as it results in the reactivation of retroelements and subsequent genomic instability. Accumulating data on LINE-1 aberrant methylation in different tumor types indicates its significant role in cancer initiation and progression. However, direct evidence that LINE-1 activation can be used as a cancer biomarker is still limited. The objective of this review was to critically evaluate the published results regarding the diagnostic/prognostic potential of the LINE-1 methylation status in cancer. Our analysis indicates that LINE-1 hypomethylation is a promising candidate biomarker of cancer development, which, however, needs validation in both clinical and laboratory studies to confirm its applicability to different cancer types and/or stages. As LINE-1 is present in multiple cell-free copies in blood, it has advantages over single-copy genes regarding perspectives of using its methylation status as an epigenetic cancer biomarker for cell-free DNA liquid biopsy.
Collapse
|
103
|
Zeggar HR, How-Kit A, Daunay A, Bettaieb I, Sahbatou M, Rahal K, Adouni O, Gammoudi A, Douik H, Deleuze JF, Kharrat M. Tumor DNA hypomethylation of LINE-1 is associated with low tumor grade of breast cancer in Tunisian patients. Oncol Lett 2020; 20:1999-2006. [PMID: 32724446 PMCID: PMC7377197 DOI: 10.3892/ol.2020.11745] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Accepted: 05/19/2020] [Indexed: 12/24/2022] Open
Abstract
DNA hypomethylation of long interspersed repetitive DNA retrotransposon (LINE-1) and Alu repeats elements of short interspersed elements family (SINEs) is an early event in carcinogenesis that causes transcriptional activation and leads to chromosomal instability. In the current study, DNA methylation levels of LINE-1 and Alu repeats were analyzed in tumoral tissues of invasive breast cancer in a Tunisian cohort and its association with the clinicopathological features of patients was defined. DNA methylation of LINE-1 and Alu repeats were analyzed using pyrosequencing in 61 invasive breast cancers. Median values observed for DNA methylation of LINE-1 and Alu repeats were considered as the cut-off (59.81 and 18.49%, respectively). The results of the current study demonstrated a positive correlation between DNA methylation levels of LINE-1 and Alu repeats (rho=0.284; P<0.03). DNA hypomethylation of LINE-1 was also indicated to be associated with low grade (P=0.023). To the best of our knowledge, the current study is the first study regarding DNA methylation of LINE-1 and Alu repeats element in breast cancer of the Tunisian population. The results of the current study suggest that, since hypomethylation of LINE-1 is associated with low grade, it could be used as a biomarker for prognosis for patients with breast cancer.
Collapse
Affiliation(s)
- Hayet Radia Zeggar
- University of Tunis El Manar, Faculty of Medicine of Tunis, LR99ES10 Human Genetics Laboratory, 1007 Tunis, Tunisia
| | - Alexandre How-Kit
- Laboratoire de Génomique, Fondation Jean Dausset-CEPH, Centre d'Etude du Polymorphisme Humain, 75010 Paris, France
| | - Antoine Daunay
- Laboratoire de Génomique, Fondation Jean Dausset-CEPH, Centre d'Etude du Polymorphisme Humain, 75010 Paris, France
| | - Ilhem Bettaieb
- Department of Immunohistocytology, Salah Azaïz Cancer Institute, 1006 Tunis, Tunisia
| | - Mourad Sahbatou
- Laboratoire de Biostatistique, Fondation Jean Dausset-CEPH, Centre d'Etude du Polymorphisme Humain, 75010 Paris, France
| | - Khaled Rahal
- Service de Chirurgie Carcinologique, Institut Salah Azaiz de Tunis, 1006 Tunis, Tunisia
| | - Olfa Adouni
- Department of Immunohistocytology, Salah Azaïz Cancer Institute, 1006 Tunis, Tunisia
| | - Amor Gammoudi
- Department of Immunohistocytology, Salah Azaïz Cancer Institute, 1006 Tunis, Tunisia
| | - Hayet Douik
- University of Tunis El Manar, Faculty of Medicine of Tunis, LR99ES10 Human Genetics Laboratory, 1007 Tunis, Tunisia
| | - Jean-François Deleuze
- Laboratoire de Génomique, Fondation Jean Dausset-CEPH, Centre d'Etude du Polymorphisme Humain, 75010 Paris, France
- Centre National de Recherche en Génomique Humaine, CEA, Le Commissariat à l'énergie atomique et aux énergies alternatives-Institut François Jacob, 92265 Evry, France
| | - Maher Kharrat
- University of Tunis El Manar, Faculty of Medicine of Tunis, LR99ES10 Human Genetics Laboratory, 1007 Tunis, Tunisia
| |
Collapse
|
104
|
Potabattula R, Zacchini F, Ptak GE, Dittrich M, Müller T, El Hajj N, Hahn T, Drummer C, Behr R, Lucas‐Hahn A, Niemann H, Schorsch M, Haaf T. Increasing methylation of sperm rDNA and other repetitive elements in the aging male mammalian germline. Aging Cell 2020; 19:e13181. [PMID: 32608562 PMCID: PMC7431825 DOI: 10.1111/acel.13181] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 05/06/2020] [Accepted: 06/01/2020] [Indexed: 01/08/2023] Open
Abstract
In somatic cells/tissues, methylation of ribosomal DNA (rDNA) increases with age and age‐related pathologies, which has a direct impact on the regulation of nucleolar activity and cellular metabolism. Here, we used bisulfite pyrosequencing and show that methylation of the rDNA transcription unit including upstream control element (UCE), core promoter, 18S rDNA, and 28S rDNA in human sperm also significantly increases with donor's age. This positive correlation between sperm rDNA methylation and biological age is evolutionarily conserved among mammals with widely different life spans such as humans, marmoset, bovine, and mouse. Similar to the tandemly repeated rDNA, methylation of human α‐satellite and interspersed LINE1 repeats, marmoset α‐satellite, bovine alpha‐ and testis satellite I, mouse minor and major satellite, and LINE1‐T repeats increases in the aging male germline, probably related to their sperm histone packaging. Deep bisulfite sequencing of single rDNA molecules in human sperm revealed that methylation does not only depend on donor's age, but also depend on the region and sequence context (A vs. G alleles). Both average rDNA methylation of all analyzed DNA molecules and the number of fully (>50%) methylated alleles, which are thought to be epigenetically silenced, increase with donor's age. All analyzed CpGs in the sperm rDNA transcription unit show comparable age‐related methylation changes. Unlike other epigenetic aging markers, the rDNA clock appears to operate in similar ways in germline and soma in different mammalian species. We propose that sperm rDNA methylation, directly or indirectly, influences nucleolar formation and developmental potential in the early embryo.
Collapse
Affiliation(s)
- Ramya Potabattula
- Institute of Human Genetics Julius Maximilians University Würzburg Germany
| | - Federica Zacchini
- Malopolska Centre of Biotechnology Jagiellonian University Krakow Poland
- Percuros B.V. Leiden The Netherlands
| | - Grazyna Ewa Ptak
- Malopolska Centre of Biotechnology Jagiellonian University Krakow Poland
| | - Marcus Dittrich
- Institute of Human Genetics Julius Maximilians University Würzburg Germany
- Department of Bioinformatics Julius Maximilians University Würzburg Germany
| | - Tobias Müller
- Department of Bioinformatics Julius Maximilians University Würzburg Germany
| | - Nady El Hajj
- Institute of Human Genetics Julius Maximilians University Würzburg Germany
- College of Health and Life Sciences Hamad Bin Khalifa University Doha Qatar
| | | | - Charis Drummer
- Platform Degenerative Diseases Leibniz Institute for Primate Research Göttingen Germany
- German Center for Cardiovascular Research, Partner Site Göttingen Göttingen Germany
| | - Rüdiger Behr
- Platform Degenerative Diseases Leibniz Institute for Primate Research Göttingen Germany
- German Center for Cardiovascular Research, Partner Site Göttingen Göttingen Germany
| | - Andrea Lucas‐Hahn
- Institute of Farm Animal Genetics Friedrich‐Loeffler‐Institute Mariensee/Neustadt Germany
| | - Heiner Niemann
- Clinic for Gastroenterology, Hepatology and Endocrinology Medical University Hannover Hannover Germany
| | | | - Thomas Haaf
- Institute of Human Genetics Julius Maximilians University Würzburg Germany
| |
Collapse
|
105
|
Novel candidate genes for ECT response prediction-a pilot study analyzing the DNA methylome of depressed patients receiving electroconvulsive therapy. Clin Epigenetics 2020; 12:114. [PMID: 32727556 PMCID: PMC7388224 DOI: 10.1186/s13148-020-00891-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Accepted: 06/23/2020] [Indexed: 01/07/2023] Open
Abstract
Background Major depressive disorder (MDD) represents a serious global health concern. The urge for efficient MDD treatment strategies is presently hindered by the incomplete knowledge of its underlying pathomechanism. Despite recent progress (highlighting both genetics and the environment, and thus DNA methylation, to be relevant for its development), 30–50% of MDD patients still fail to reach remission with standard treatment approaches. Electroconvulsive therapy (ECT) is one of the most powerful options for the treatment of pharmacoresistant depression; nevertheless, ECT remission rates barely reach 50% in large-scale naturalistic population-based studies. To optimize MDD treatment strategies and enable personalized medicine in the long- term, prospective indicators of ECT response are thus in great need. Because recent target-driven analyses revealed DNA methylation baseline differences between ECT responder groups, we analyzed the DNA methylome of depressed ECT patients using next-generation sequencing. In this pilot study, we did not only aim to find novel targets for ECT response prediction but also to get a deeper insight into its possible mechanism of action. Results Longitudinal DNA methylation analysis of peripheral blood mononuclear cells isolated from a cohort of treatment-resistant MDD patients (n = 12; time points: before and after 1st and last ECT, respectively) using a TruSeq-Methyl Capture EPIC Kit for library preparation, led to the following results: (1) The global DNA methylation differed neither between the four measured time points nor between ECT responders (n = 8) and non-responders (n = 4). (2) Analyzing the DNA methylation variance for every probe (=1476812 single CpG sites) revealed eight novel candidate genes to be implicated in ECT response (protein-coding genes: RNF175, RNF213, TBC1D14, TMC5, WSCD1; genes encoding for putative long non-coding RNA transcripts: AC018685.2, AC098617.1, CLCN3P1). (3) In addition, DNA methylation of two CpG sites (located within AQP10 and TRERF1) was found to change during the treatment course. Conclusions We suggest ten novel candidate genes to be implicated in either ECT response or its possible mechanism. Because of the small sample size of our pilot study, our findings must be regarded as preliminary.
Collapse
|
106
|
Abstract
Multicellular eukaryotic genomes show enormous differences in size. A substantial part of this variation is due to the presence of transposable elements (TEs). They contribute significantly to a cell's mass of DNA and have the potential to become involved in host gene control. We argue that the suppression of their activities by methylation of the C-phosphate-G (CpG) dinucleotide in DNA is essential for their long-term accommodation in the host genome and, therefore, to its expansion. An inevitable consequence of cytosine methylation is an increase in C-to-T transition mutations via deamination, which causes CpG loss. Cytosine deamination is often needed for TEs to take on regulatory functions in the host genome. Our study of the whole-genome sequences of 53 organisms showed a positive correlation between the size of a genome and the percentage of TEs it contains, as well as a negative correlation between size and the CpG observed/expected (O/E) ratio in both TEs and the host DNA. TEs are seldom found at promoters and transcription start sites, but they are found more at enhancers, particularly after they have accumulated C-to-T and other mutations. Therefore, the methylation of TE DNA allows for genome expansion and also leads to new opportunities for gene control by TE-based regulatory sites.
Collapse
|
107
|
Alhaji SY, Nordin N, Ngai SC, Al Abbar A, Mei L, Abdullah S. Lack of methylation on transgene leads to high level and persistent transgene expression in induced pluripotent stem cells. Gene 2020; 758:144958. [PMID: 32683073 DOI: 10.1016/j.gene.2020.144958] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 06/22/2020] [Accepted: 07/13/2020] [Indexed: 11/30/2022]
Abstract
Short-lived therapeutic gene expression in mammalian cells by DNA methylation is one of the major challenges in gene therapy. In this study, we assessed the implication of DNA methylation on the duration of GFP expression in mouse embryonic stem (ES) and mouse induced pluripotent stem (iPS) cells. The cells were transduced with lentivirus (LV) carrying green fluorescent protein (GFP) driven by either human elongation factor (EF1α) or cytomegalovirus (CMV) promoter. Transduced iPS cells exhibited higher percentage of GFP+ cells with persistent mean fluorescent intensity than transduced ES cells. Analysis on the integrated copy of transgene in the population of the transduced cells demonstrated similar copy number. However, significant increase in GFP intensity following 5-azaC treatment was observed in transduced ES cells only, suggesting the influence of DNA methylation in transgene silencing. Subsequent DNA methylation analysis showed that the promoter and the GFP region of the provirus in iPS cells had negligible methylation profile compared to transduced ES cells. Interestingly, sustained transgene expression was observed upon directed differentiation of transduced iPS cells towards CD34+ CD45+ cells. Hence, this study has shown that favourable transgene activity from lentiviral transduced iPS cells was due to the lack of methylation at the proviral regions.
Collapse
Affiliation(s)
- Suleiman Yusuf Alhaji
- Medical Genetics Laboratory, Department of Biomedical Sciences, Faculty of Medicine & Health Sciences, Universiti Putra Malaysia, 43400 UPM Selangor, Malaysia; Department of Human Anatomy, College of Medical Sciences, Abubakar Tafawa Balewa University Bauchi, 740272 ATBU, Nigeria; Molecular Genetics and Infectious Diseases Research Laboratory, College of Medical Sciences, Abubakar Tafawa Balewa University Bauchi, 740272 ATBU, Nigeria
| | - Norshariza Nordin
- Medical Genetics Laboratory, Department of Biomedical Sciences, Faculty of Medicine & Health Sciences, Universiti Putra Malaysia, 43400 UPM Selangor, Malaysia; Genetics & Regenerative Medicine Research Centre, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 UPM Selangor, Malaysia
| | - Siew Ching Ngai
- School of Biosciences, Faculty of Science and Engineering, University of Nottingham Malaysia, 43500 Semenyih, Selangor, Malaysia
| | - Akram Al Abbar
- Medical Genetics Laboratory, Department of Biomedical Sciences, Faculty of Medicine & Health Sciences, Universiti Putra Malaysia, 43400 UPM Selangor, Malaysia
| | - Lai Mei
- Genetics & Regenerative Medicine Research Centre, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 UPM Selangor, Malaysia; Department of Pathology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 UPM Selangor, Malaysia
| | - Syahril Abdullah
- Medical Genetics Laboratory, Department of Biomedical Sciences, Faculty of Medicine & Health Sciences, Universiti Putra Malaysia, 43400 UPM Selangor, Malaysia; Genetics & Regenerative Medicine Research Centre, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 UPM Selangor, Malaysia; UPM-MAKNA Cancer Research Laboratory, Institute of Bioscience, Universiti Putra Malaysia, 43400 UPM Selangor, Malaysia.
| |
Collapse
|
108
|
DNA methylation dynamics at transposable elements in mammals. Essays Biochem 2020; 63:677-689. [PMID: 31654072 DOI: 10.1042/ebc20190039] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2019] [Revised: 09/29/2019] [Accepted: 09/30/2019] [Indexed: 12/18/2022]
Abstract
Transposable elements dominate the mammalian genome, but their contribution to genetic and epigenetic regulation has been largely overlooked. This was in part due to technical limitations, which made the study of repetitive sequences at single copy resolution difficult. The advancement of next-generation sequencing assays in the last decade has greatly enhanced our understanding of transposable element function. In some instances, specific transposable elements are thought to have been co-opted into regulatory roles during both mouse and human development, while in disease such regulatory potential can contribute to malignancy. DNA methylation is arguably the best characterised regulator of transposable element activity. DNA methylation is associated with transposable element repression, and acts to limit their genotoxic potential. In specific developmental contexts, erasure of DNA methylation is associated with a burst of transposable element expression. Developmental regulation of DNA methylation enables transposon activation, ensuring their survival and propagation throughout the host genome, and also allows the host access to regulatory sequences encoded within the elements. Here I discuss DNA methylation at transposable elements, describing its function and dynamic regulation throughout murine and human development.
Collapse
|
109
|
Jönsson ME, Garza R, Johansson PA, Jakobsson J. Transposable Elements: A Common Feature of Neurodevelopmental and Neurodegenerative Disorders. Trends Genet 2020; 36:610-623. [PMID: 32499105 DOI: 10.1016/j.tig.2020.05.004] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 05/11/2020] [Accepted: 05/13/2020] [Indexed: 12/30/2022]
Abstract
The etiology of most neurological disorders is poorly understood and current treatments are largely ineffective. New ideas and concepts are therefore vitally important for future research in this area. This review explores the concept that dysregulation of transposable elements (TEs) contributes to the appearance and pathology of neurodevelopmental and neurodegenerative disorders. Despite TEs making up at least half of the human genome, they are vastly understudied in relation to brain disorders. However, recent advances in sequencing technologies and gene editing approaches are now starting to unravel the pathological role of TEs. Aberrant activation of TEs has been found in many neurological disorders; the resulting pathogenic effects, which include alterations of gene expression, neuroinflammation, and direct neurotoxicity, are starting to be resolved. An increased understanding of the relationship between TEs and pathological processes in the brain improves the potential for novel diagnostics and interventions for brain disorders.
Collapse
Affiliation(s)
- Marie E Jönsson
- Laboratory of Molecular Neurogenetics, Department of Experimental Medical Science, Wallenberg Neuroscience Center and Lund Stem Cell Center, BMC A11, Lund University, 221 84 Lund, Sweden
| | - Raquel Garza
- Laboratory of Molecular Neurogenetics, Department of Experimental Medical Science, Wallenberg Neuroscience Center and Lund Stem Cell Center, BMC A11, Lund University, 221 84 Lund, Sweden
| | - Pia A Johansson
- Laboratory of Molecular Neurogenetics, Department of Experimental Medical Science, Wallenberg Neuroscience Center and Lund Stem Cell Center, BMC A11, Lund University, 221 84 Lund, Sweden
| | - Johan Jakobsson
- Laboratory of Molecular Neurogenetics, Department of Experimental Medical Science, Wallenberg Neuroscience Center and Lund Stem Cell Center, BMC A11, Lund University, 221 84 Lund, Sweden.
| |
Collapse
|
110
|
Transposon Reactivation in the Germline May Be Useful for Both Transposons and Their Host Genomes. Cells 2020; 9:cells9051172. [PMID: 32397241 PMCID: PMC7290860 DOI: 10.3390/cells9051172] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 05/05/2020] [Accepted: 05/07/2020] [Indexed: 12/29/2022] Open
Abstract
Transposable elements (TEs) are long-term residents of eukaryotic genomes that make up a large portion of these genomes. They can be considered as perfectly fine members of genomes replicating with resident genes and being transmitted vertically to the next generation. However, unlike regular genes, TEs have the ability to send new copies to new sites. As such, they have been considered as parasitic members ensuring their own replication. In another view, TEs may also be considered as symbiotic sequences providing shared benefits after mutualistic interactions with their host genome. In this review, we recall the relationship between TEs and their host genome and discuss why transient relaxation of TE silencing within specific developmental windows may be useful for both.
Collapse
|
111
|
Thrasyvoulou S, Vartholomatos G, Markopoulos G, Noutsopoulos D, Mantziou S, Gkartziou F, Papageorgis P, Charchanti A, Kouklis P, Constantinou AI, Tzavaras T. VL30 retrotransposition is associated with induced EMT, CSC generation and tumorigenesis in HC11 mouse mammary stem‑like epithelial cells. Oncol Rep 2020; 44:126-138. [PMID: 32377731 PMCID: PMC7251778 DOI: 10.3892/or.2020.7596] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Accepted: 02/05/2020] [Indexed: 12/11/2022] Open
Abstract
Retrotransposons copy their sequences via an RNA intermediate, followed by reverse transcription into cDNA and random insertion, into a new genomic locus. New retrotransposon copies may lead to cell transformation and/or tumorigenesis through insertional mutagenesis. Methylation is a major defense mechanism against retrotransposon RNA expression and retrotransposition in differentiated cells, whereas stem cells are relatively hypo-methylated. Epithelial-to-mesenchymal transition (EMT), which transforms normal epithelial cells into mesenchymal-like cells, also contributes to tumor progression and tumor metastasis. Cancer stem cells (CSCs), a fraction of undifferentiated tumor-initiating cancer cells, are reciprocally related to EMT. In the present study, the outcome of long terminal repeat (LTR)-Viral-Like 30 (VL30) retrotransposition was examined in mouse mammary stem-like/progenitor HC11 epithelial cells. The transfection of HC11 cells with a VL30 retrotransposon, engineered with an EGFP-based retrotransposition cassette, elicited a higher retrotransposition frequency in comparison to differentiated J3B1A and C127 mouse mammary cells. Fluorescence microscopy and PCR analysis confirmed the specificity of retrotransposition events. The differentiated retrotransposition-positive cells retained their epithelial morphology, while the respective HC11 cells acquired mesenchymal features associated with the loss of E-cadherin, the induction of N-cadherin, and fibronectin and vimentin protein expression, as well as an increased transforming growth factor (TGF)-β1, Slug, Snail-1 and Twist mRNA expression. In addition, they were characterized by cell proliferation in low serum, and the acquisition of CSC-like properties indicated by mammosphere formation under anchorage-independent conditions. Mammospheres exhibited an increased Nanog and Oct4 mRNA expression and a CD44+/CD24−/low antigenic phenotype, as well as self-renewal and differentiation capacity, forming mammary acini-like structures. DNA sequencing analysis of retrotransposition-positive HC11 cells revealed retrotransposed VL30 copies integrated at the vicinity of EMT-, cancer type- and breast cancer-related genes. The inoculation of these cells into Balb/c mice produced cytokeratin-positive tumors containing pancytokeratin-positive cells, indicative of cell invasion features. On the whole, the findings of the present study demonstrate, for the first time, to the best of our knowledge, that stem-like epithelial HC11 cells are amenable to VL30 retrotransposition associated with the induction of EMT and CSC generation, leading to tumorigenesis.
Collapse
Affiliation(s)
- Soteroula Thrasyvoulou
- Laboratory of General Biology, School of Health Sciences, Faculty of Medicine, University of Ioannina, 45110 Ioannina, Greece
| | - Georgios Vartholomatos
- Laboratory of Hematology, Unit of Molecular Biology, University Hospital of Ioannina, 45110 Ioannina, Greece
| | - Georgios Markopoulos
- Laboratory of General Biology, School of Health Sciences, Faculty of Medicine, University of Ioannina, 45110 Ioannina, Greece
| | - Dimitrios Noutsopoulos
- Laboratory of General Biology, School of Health Sciences, Faculty of Medicine, University of Ioannina, 45110 Ioannina, Greece
| | - Stefania Mantziou
- Laboratory of General Biology, School of Health Sciences, Faculty of Medicine, University of Ioannina, 45110 Ioannina, Greece
| | - Foteini Gkartziou
- Laboratory of General Biology, School of Health Sciences, Faculty of Medicine, University of Ioannina, 45110 Ioannina, Greece
| | - Panagiotis Papageorgis
- Biological Sciences Program, Department of Life Sciences, School of Sciences, European University Cyprus, 2404 Nicosia, Cyprus
| | - Antonia Charchanti
- Laboratory of Anatomy‑Histology‑Embryology, School of Health Sciences, Faculty of Medicine, University of Ioannina, 45110 Ioannina, Greece
| | - Panos Kouklis
- Laboratory of General Biology, School of Health Sciences, Faculty of Medicine, University of Ioannina, 45110 Ioannina, Greece
| | - Andreas I Constantinou
- Department of Biological Sciences, Faculty of Pure and Applied Sciences, University of Cyprus, 1678 Nicosia, Cyprus
| | - Theodore Tzavaras
- Laboratory of General Biology, School of Health Sciences, Faculty of Medicine, University of Ioannina, 45110 Ioannina, Greece
| |
Collapse
|
112
|
Kint S, Trypsteen W, De Spiegelaere W, Malatinkova E, Kinloch-de Loes S, De Meyer T, Van Criekinge W, Vandekerckhove L. Underestimated effect of intragenic HIV-1 DNA methylation on viral transcription in infected individuals. Clin Epigenetics 2020; 12:36. [PMID: 32111236 PMCID: PMC7049218 DOI: 10.1186/s13148-020-00829-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Accepted: 02/16/2020] [Indexed: 12/13/2022] Open
Abstract
Background The HIV-1 proviral genome harbors multiple CpG islands (CpGIs), both in the promoter and intragenic regions. DNA methylation in the promoter region has been shown to be heavily involved in HIV-1 latency regulation in cultured cells. However, its exact role in proviral transcriptional regulation in infected individuals is poorly understood or characterized. Moreover, methylation at intragenic CpGIs has never been studied in depth. Results A large, well-characterized HIV-1 patient cohort (n = 72), consisting of 17 long-term non-progressors and 8 recent seroconverters (SRCV) without combination antiretroviral therapy (cART), 15 early cART-treated, and 32 late cART-treated patients, was analyzed using a next-generation bisulfite sequencing DNA methylation method. In general, we observed low level of promoter methylation and higher levels of intragenic methylation. Additionally, SRCV showed increased promoter methylation and decreased intragenic methylation compared with the other patient groups. This data indicates that increased intragenic methylation could be involved in proviral transcriptional regulation. Conclusions Contrasting in vitro studies, our results indicate that intragenic hypermethylation of HIV-1 proviral DNA is an underestimated factor in viral control in HIV-1-infected individuals, showing the importance of analyzing the complete proviral genome in future DNA methylation studies.
Collapse
Affiliation(s)
- Sam Kint
- HIV Cure Research Center, Department of Internal Medicine and Pediatrics, Faculty of Medicine and Health Sciences, Ghent University and Ghent University Hospital, Corneel Heymanslaan 10, Medical Research Building 2, 9000, Ghent, Belgium.,Biobix, Department of Data Analysis and Mathematical Modelling, Faculty of Bio-science Engineering, Ghent University, Coupure Links 653, 9000, Ghent, Belgium
| | - Wim Trypsteen
- HIV Cure Research Center, Department of Internal Medicine and Pediatrics, Faculty of Medicine and Health Sciences, Ghent University and Ghent University Hospital, Corneel Heymanslaan 10, Medical Research Building 2, 9000, Ghent, Belgium
| | - Ward De Spiegelaere
- Department of Morphology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820, Merelbeke, Belgium
| | - Eva Malatinkova
- HIV Cure Research Center, Department of Internal Medicine and Pediatrics, Faculty of Medicine and Health Sciences, Ghent University and Ghent University Hospital, Corneel Heymanslaan 10, Medical Research Building 2, 9000, Ghent, Belgium
| | - Sabine Kinloch-de Loes
- Division of Infection and Immunity, Royal Free Hospital, Royal Free Campus, University College London, Pont St, Hampstead, London, NW3 2QG, UK
| | - Tim De Meyer
- Biobix, Department of Data Analysis and Mathematical Modelling, Faculty of Bio-science Engineering, Ghent University, Coupure Links 653, 9000, Ghent, Belgium
| | - Wim Van Criekinge
- Biobix, Department of Data Analysis and Mathematical Modelling, Faculty of Bio-science Engineering, Ghent University, Coupure Links 653, 9000, Ghent, Belgium
| | - Linos Vandekerckhove
- HIV Cure Research Center, Department of Internal Medicine and Pediatrics, Faculty of Medicine and Health Sciences, Ghent University and Ghent University Hospital, Corneel Heymanslaan 10, Medical Research Building 2, 9000, Ghent, Belgium.
| |
Collapse
|
113
|
Tristan-Ramos P, Morell S, Sanchez L, Toledo B, Garcia-Perez JL, Heras SR. sRNA/L1 retrotransposition: using siRNAs and miRNAs to expand the applications of the cell culture-based LINE-1 retrotransposition assay. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190346. [PMID: 32075559 DOI: 10.1098/rstb.2019.0346] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The cell culture-based retrotransposition reporter assay has been (and is) an essential tool for the study of vertebrate Long INterspersed Elements (LINEs). Developed more than 20 years ago, this assay has been instrumental in characterizing the role of LINE-encoded proteins in retrotransposition, understanding how ribonucleoprotein particles are formed, how host factors regulate LINE mobilization, etc. Moreover, variations of the conventional assay have been developed to investigate the biology of other currently active human retrotransposons, such as Alu and SVA. Here, we describe a protocol that allows combination of the conventional cell culture-based LINE-1 retrotransposition reporter assay with short interfering RNAs (siRNAs) and microRNA (miRNAs) mimics or inhibitors, which has allowed us to uncover specific miRNAs and host factors that regulate retrotransposition. The protocol described here is highly reproducible, quantitative, robust and flexible, and allows the study of several small RNA classes and various retrotransposons. To illustrate its utility, here we show that siRNAs to Fanconi anaemia proteins (FANC-A and FANC-C) and an inhibitor of miRNA-20 upregulate and downregulate human L1 retrotransposition, respectively. This article is part of a discussion meeting issue 'Crossroads between transposons and gene regulation'.
Collapse
Affiliation(s)
- Pablo Tristan-Ramos
- Centre for Genomics and Oncological Research: Pfizer/University of Granada/Andalusian Regional Government, PTS Granada, GENYO, Granada, Spain.,Department of Biochemistry and Molecular Biology II, Faculty of Pharmacy, University of Granada, Granada, Spain
| | - Santiago Morell
- Centre for Genomics and Oncological Research: Pfizer/University of Granada/Andalusian Regional Government, PTS Granada, GENYO, Granada, Spain
| | - Laura Sanchez
- Centre for Genomics and Oncological Research: Pfizer/University of Granada/Andalusian Regional Government, PTS Granada, GENYO, Granada, Spain
| | - Belen Toledo
- Centre for Genomics and Oncological Research: Pfizer/University of Granada/Andalusian Regional Government, PTS Granada, GENYO, Granada, Spain.,Department of Biochemistry and Molecular Biology II, Faculty of Pharmacy, University of Granada, Granada, Spain
| | - Jose L Garcia-Perez
- Centre for Genomics and Oncological Research: Pfizer/University of Granada/Andalusian Regional Government, PTS Granada, GENYO, Granada, Spain.,MRC-Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Edinburgh, UK
| | - Sara R Heras
- Centre for Genomics and Oncological Research: Pfizer/University of Granada/Andalusian Regional Government, PTS Granada, GENYO, Granada, Spain.,Department of Biochemistry and Molecular Biology II, Faculty of Pharmacy, University of Granada, Granada, Spain
| |
Collapse
|
114
|
Fouché S, Badet T, Oggenfuss U, Plissonneau C, Francisco CS, Croll D. Stress-Driven Transposable Element De-repression Dynamics and Virulence Evolution in a Fungal Pathogen. Mol Biol Evol 2020; 37:221-239. [PMID: 31553475 DOI: 10.1093/molbev/msz216] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Transposable elements (TEs) are drivers of genome evolution and affect the expression landscape of the host genome. Stress is a major factor inducing TE activity; however, the regulatory mechanisms underlying de-repression are poorly understood. Plant pathogens are excellent models to dissect the impact of stress on TEs. The process of plant infection induces stress for the pathogen, and virulence factors (i.e., effectors) located in TE-rich regions become expressed. To dissect TE de-repression dynamics and contributions to virulence, we analyzed the TE expression landscape of four strains of the major wheat pathogen Zymoseptoria tritici. We experimentally exposed strains to nutrient starvation and host infection stress. Contrary to expectations, we show that the two distinct conditions induce the expression of different sets of TEs. In particular, the most highly expressed TEs, including miniature inverted-repeat transposable element and long terminal repeat-Gypsy element, show highly distinct de-repression across stress conditions. Both the genomic context of TEs and the genetic background stress (i.e., different strains harboring the same TEs) were major predictors of de-repression under stress. Gene expression profiles under stress varied significantly depending on the proximity to the closest TEs and genomic defenses against TEs were largely ineffective to prevent de-repression. Next, we analyzed the locus encoding the Avr3D1 effector. We show that the insertion and subsequent silencing of TEs in close proximity likely contributed to reduced expression and virulence on a specific wheat cultivar. The complexity of TE responsiveness to stress across genetic backgrounds and genomic locations demonstrates substantial intraspecific genetic variation to control TEs with consequences for virulence.
Collapse
Affiliation(s)
- Simone Fouché
- Plant Pathology, Institute of Integrative Biology, ETH Zürich, Zürich, Switzerland.,Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Thomas Badet
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Ursula Oggenfuss
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Clémence Plissonneau
- Plant Pathology, Institute of Integrative Biology, ETH Zürich, Zürich, Switzerland
| | | | - Daniel Croll
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| |
Collapse
|
115
|
Lu W, Xiao L, Quan M, Wang Q, El-Kassaby YA, Du Q, Zhang D. Linkage-linkage disequilibrium dissection of the epigenetic quantitative trait loci (epiQTLs) underlying growth and wood properties in Populus. THE NEW PHYTOLOGIST 2020; 225:1218-1233. [PMID: 31560799 DOI: 10.1111/nph.16220] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 09/17/2019] [Indexed: 05/21/2023]
Abstract
Increasing evidence indicates that DNA methylation is heritable and serves as an essential marker contributing to phenotypic variation. Linkage-linkage disequilibrium mapping was used to decipher the epigenetic architecture underlying nine growth and wood property traits in a linkage population (550 F1 progeny) and a natural population (435 unrelated individuals) of Populus using methylation-sensitive amplification polymorphism (MSAP)-based analysis. The interactions between genetic and epigenetic variants in the causative genes was further unveiled using expression quantitative trait methylation (eQTM) and nucleotide (eQTN) mapping strategies. A total of 163 epigenetic quantitative trait loci (epiQTLs; LOD ≥ 3.0), explaining 1.7-44.5% of phenotypic variations, were mapped to a high-resolution epigenetic map with 19 linkage groups, which was supported by the significant MSAP associations (P < 0.001) in the two populations. There were 23 causal genes involved in growth regulation and wood formation, whose markers were located in epiQTLs and associated with the same traits in both populations. Further eQTN and eQTM mapping showed that causal genetic and epigenetic variants within the 23 candidate genes may interact more in trans in gene expression and phenotype. The present study provides strategies for investigating epigenetic architecture and the interaction between genetic and epigenetic variants modulating complex traits in forest trees.
Collapse
Affiliation(s)
- Wenjie Lu
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, College of Biological Sciences and Technology, Beijing Forestry University, No. 35, Qinghua East Road, Beijing, 100083, China
- National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, 35 Qinghua East Road, Beijing, China
- Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Technology, Beijing Forestry University, 35 Qinghua East Road, Beijing, China
| | - Liang Xiao
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, College of Biological Sciences and Technology, Beijing Forestry University, No. 35, Qinghua East Road, Beijing, 100083, China
- National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, 35 Qinghua East Road, Beijing, China
- Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Technology, Beijing Forestry University, 35 Qinghua East Road, Beijing, China
| | - Mingyang Quan
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, College of Biological Sciences and Technology, Beijing Forestry University, No. 35, Qinghua East Road, Beijing, 100083, China
- National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, 35 Qinghua East Road, Beijing, China
- Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Technology, Beijing Forestry University, 35 Qinghua East Road, Beijing, China
| | - Qingshi Wang
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, College of Biological Sciences and Technology, Beijing Forestry University, No. 35, Qinghua East Road, Beijing, 100083, China
- National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, 35 Qinghua East Road, Beijing, China
- Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Technology, Beijing Forestry University, 35 Qinghua East Road, Beijing, China
| | - Yousry A El-Kassaby
- Department of Forest and Conservation Sciences, Faculty of Forestry, Forest Sciences Centre, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Qingzhang Du
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, College of Biological Sciences and Technology, Beijing Forestry University, No. 35, Qinghua East Road, Beijing, 100083, China
- National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, 35 Qinghua East Road, Beijing, China
- Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Technology, Beijing Forestry University, 35 Qinghua East Road, Beijing, China
| | - Deqiang Zhang
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, College of Biological Sciences and Technology, Beijing Forestry University, No. 35, Qinghua East Road, Beijing, 100083, China
- National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, 35 Qinghua East Road, Beijing, China
- Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Technology, Beijing Forestry University, 35 Qinghua East Road, Beijing, China
| |
Collapse
|
116
|
Choudhary MN, Friedman RZ, Wang JT, Jang HS, Zhuo X, Wang T. Co-opted transposons help perpetuate conserved higher-order chromosomal structures. Genome Biol 2020; 21:16. [PMID: 31973766 PMCID: PMC6979391 DOI: 10.1186/s13059-019-1916-8] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Accepted: 12/08/2019] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Transposable elements (TEs) make up half of mammalian genomes and shape genome regulation by harboring binding sites for regulatory factors. These include binding sites for architectural proteins, such as CTCF, RAD21, and SMC3, that are involved in tethering chromatin loops and marking domain boundaries. The 3D organization of the mammalian genome is intimately linked to its function and is remarkably conserved. However, the mechanisms by which these structural intricacies emerge and evolve have not been thoroughly probed. RESULTS Here, we show that TEs contribute extensively to both the formation of species-specific loops in humans and mice through deposition of novel anchoring motifs, as well as to the maintenance of conserved loops across both species through CTCF binding site turnover. The latter function demonstrates the ability of TEs to contribute to genome plasticity and reinforce conserved genome architecture as redundant loop anchors. Deleting such candidate TEs in human cells leads to the collapse of conserved loop and domain structures. These TEs are also marked by reduced DNA methylation and bear mutational signatures of hypomethylation through evolutionary time. CONCLUSIONS TEs have long been considered a source of genetic innovation. By examining their contribution to genome topology, we show that TEs can contribute to regulatory plasticity by inducing redundancy and potentiating genetic drift locally while conserving genome architecture globally, revealing a paradigm for defining regulatory conservation in the noncoding genome beyond classic sequence-level conservation.
Collapse
Affiliation(s)
- Mayank Nk Choudhary
- The Edison Family Center for Genome Sciences & Systems Biology, Department of Genetics, Washington University, 4515 McKinley Avenue, Campus Box 8510, St. Louis, MO, 63110, USA
| | - Ryan Z Friedman
- The Edison Family Center for Genome Sciences & Systems Biology, Department of Genetics, Washington University, 4515 McKinley Avenue, Campus Box 8510, St. Louis, MO, 63110, USA
| | - Julia T Wang
- The Edison Family Center for Genome Sciences & Systems Biology, Department of Genetics, Washington University, 4515 McKinley Avenue, Campus Box 8510, St. Louis, MO, 63110, USA
| | - Hyo Sik Jang
- The Edison Family Center for Genome Sciences & Systems Biology, Department of Genetics, Washington University, 4515 McKinley Avenue, Campus Box 8510, St. Louis, MO, 63110, USA
| | - Xiaoyu Zhuo
- The Edison Family Center for Genome Sciences & Systems Biology, Department of Genetics, Washington University, 4515 McKinley Avenue, Campus Box 8510, St. Louis, MO, 63110, USA
| | - Ting Wang
- The Edison Family Center for Genome Sciences & Systems Biology, Department of Genetics, Washington University, 4515 McKinley Avenue, Campus Box 8510, St. Louis, MO, 63110, USA.
| |
Collapse
|
117
|
Lou C, Goodier JL, Qiang R. A potential new mechanism for pregnancy loss: considering the role of LINE-1 retrotransposons in early spontaneous miscarriage. Reprod Biol Endocrinol 2020; 18:6. [PMID: 31964400 PMCID: PMC6971995 DOI: 10.1186/s12958-020-0564-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 01/07/2020] [Indexed: 12/14/2022] Open
Abstract
LINE1 retrotransposons are mobile DNA elements that copy and paste themselves into new sites in the genome. To ensure their evolutionary success, heritable new LINE-1 insertions accumulate in cells that can transmit genetic information to the next generation (i.e., germ cells and embryonic stem cells). It is our hypothesis that LINE1 retrotransposons, insertional mutagens that affect expression of genes, may be causal agents of early miscarriage in humans. The cell has evolved various defenses restricting retrotransposition-caused mutation, but these are occasionally relaxed in certain somatic cell types, including those of the early embryo. We predict that reduced suppression of L1s in germ cells or early-stage embryos may lead to excessive genome mutation by retrotransposon insertion, or to the induction of an inflammatory response or apoptosis due to increased expression of L1-derived nucleic acids and proteins, and so disrupt gene function important for embryogenesis. If correct, a novel threat to normal human development is revealed, and reverse transcriptase therapy could be one future strategy for controlling this cause of embryonic damage in patients with recurrent miscarriages.
Collapse
Affiliation(s)
- Chao Lou
- Department of Genetics, Northwest Women’s and Children’s Hospital, 1616 Yanxiang Road, Xi’an, Shaanxi Province People’s Republic of China
| | - John L. Goodier
- 0000 0001 2171 9311grid.21107.35McKusick-Nathans Deartment of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD USA
| | - Rong Qiang
- Department of Genetics, Northwest Women’s and Children’s Hospital, 1616 Yanxiang Road, Xi’an, Shaanxi Province People’s Republic of China
| |
Collapse
|
118
|
Briggs EM, Spadafora C, Logan SK. A re-evaluation of LINE-1 ORF2 expression in LNCaP prostate cancer cells. Mob DNA 2020; 10:51. [PMID: 31890047 PMCID: PMC6935485 DOI: 10.1186/s13100-019-0196-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Accepted: 12/16/2019] [Indexed: 12/15/2022] Open
Abstract
Background We previously examined expression of Long Interspersed Element-1 (LINE-1) in a variety of prostate cancer cells including hormone-dependent LNCaP cells. These studies demonstrated expression and sub-cellular localization of LINE-1 proteins, ORF1p, with antibody 4H1, and ORF2p, with antibody chA1-L1. Results Here we conduct immunoprecipitation/mass spectrometry analysis using chA1-L1 antibody against ORF2p in LNCaP cells. Our results indicate that antigens detected by the antibody include the transcriptional regulator BCLAF1. We show that chA1-L1 recognizes BCLAF1 using siRNA knockdown and overexpression of a tagged BCLAF1. We also show that chA1-L1 antibody recognizes ORF2p in HEK293 cells overexpressing LINE-1. Further, analysis of ORF2p (chA1-L1) and BCLAF1 foci using immunofluorescence in LNCaP cells showed significant colocalization. Conclusions Overall, our findings indicate that chA1-L1 antibody recognizes both BCLAF1 and ORF2p but the majority of antigen recognized in LNCaP cells is BCLAF1.
Collapse
Affiliation(s)
- Erica M Briggs
- 1Departments of Biochemistry and Molecular Pharmacology, New York University School of Medicine, Alexandria Center for Life Sciences, 450 East 29th Street, Room 323, New York, NY 10016 USA
| | - Corrado Spadafora
- 3Institute of Translational Pharmacology, National Research Council, Rome, Italy
| | - Susan K Logan
- 1Departments of Biochemistry and Molecular Pharmacology, New York University School of Medicine, Alexandria Center for Life Sciences, 450 East 29th Street, Room 323, New York, NY 10016 USA.,2Departments of Urology, New York University School of Medicine, Alexandria Center for Life Sciences, 450 East 29th Street, Room 323, New York, NY 10016 USA
| |
Collapse
|
119
|
Moradi Sarabi M, Mohammadrezaei Khorramabadi R, Zare Z, Eftekhar E. Polyunsaturated fatty acids and DNA methylation in colorectal cancer. World J Clin Cases 2019; 7:4172-4185. [PMID: 31911898 PMCID: PMC6940323 DOI: 10.12998/wjcc.v7.i24.4172] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 11/27/2019] [Accepted: 12/13/2019] [Indexed: 02/05/2023] Open
Abstract
Colorectal cancer (CRC) has been designated a major global problem, especially due to its high prevalence in developed countries. CRC mostly occurs sporadically (75%-80%), and only 20%-25% of patients have a family history. Several processes are involved in the development of CRC such as a combination of genetic and epigenetic alterations. Epigenetic changes, including DNA methylation play a vital role in the progression of CRC. Complex interactions between susceptibility genes and environmental factors, such as a diet and sedentary lifestyle, lead to the development of CRC. Clinical and experimental studies have confirmed the beneficial effects of dietary polyunsaturated fatty acids (PUFAs) in preventing CRC. From a mechanistic viewpoint, it has been suggested that PUFAs are pleiotropic agents that alter chromatin remodeling, membrane structure and downstream cell signaling. Moreover, PUFAs can alter the epigenome via modulation of DNA methylation. In this review, we summarize recent investigations linking PUFAs and DNA methylation-associated CRC risk.
Collapse
Affiliation(s)
- Mostafa Moradi Sarabi
- Department of Biochemistry and Genetics, School of Medicine, Lorestan University of Medical Sciences, Khorramabad 381251698, Iran
| | - Reza Mohammadrezaei Khorramabadi
- Department of Biochemistry and Genetics, School of Medicine, Lorestan University of Medical Sciences, Khorramabad 381251698, Iran
| | - Zohre Zare
- Department of Pharmaceutics, School of Pharmacy, Lorestan University of Medical Sciences, Khorramabad 381251698, Iran
| | - Ebrahim Eftekhar
- Molecular Medicine Research Center, Hormozgan Health Institute, Hormozgan University of Medical Sciences, Bandar Abbas 7919915519, Iran
| |
Collapse
|
120
|
Dan H, Zhang S, Zhou Y, Guan Q. DNA Methyltransferase Inhibitors: Catalysts For Antitumour Immune Responses. Onco Targets Ther 2019; 12:10903-10916. [PMID: 31849494 PMCID: PMC6913319 DOI: 10.2147/ott.s217767] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 10/02/2019] [Indexed: 12/15/2022] Open
Abstract
Epigenetics is a kind of heritable change that involves the unaltered DNA sequence and can have effects on gene expression. The regulatory mechanism mainly includes DNA methylation, histone modification and non-coding RNA regulation. DNA methylation is currently the most studied aspect of epigenetics. It is widely present in eukaryotic cells and is the most important epigenetic mark in the regulation of gene expression in the cell. DNA methyltransferase inhibitors (DNMTi) have been increasingly recognized in the field of cancer immunotherapy, have been approved for the treatment of acute myeloid leukaemia (AML) and are widely being used in clinical trials of cancer immunotherapies. DNMTi promote the reactivation of tumour suppressor genes, enhance tumour immunogenicity, and stimulate a variety of immune cells to secrete cytokines that exert cytotoxic effects, promote tumour cell death, including macrophages, natural killer (NK) cells and CD8+ T cells, and upregulate major histocompatibility complex (MHC) class I expression levels. Here, we mainly summarize the epigenetics related to DNMTi and their regulation of the antitumour immune response and DNMTi combined with immuno-therapeutics or histone deacetylase inhibitors to demonstrate the great development potential and clinical application value of DNMTi.
Collapse
Affiliation(s)
- Huimin Dan
- Gansu Province Key Laboratory of Gastrointestinal Diseases, The First Hospital of Lanzhou University, Lanzhou University, Lanzhou, Gansu Province, People's Republic of China
| | - Shanshan Zhang
- Gansu Province Key Laboratory of Gastrointestinal Diseases, The First Hospital of Lanzhou University, Lanzhou University, Lanzhou, Gansu Province, People's Republic of China
| | - Yongning Zhou
- Gansu Province Key Laboratory of Gastrointestinal Diseases, The First Hospital of Lanzhou University, Lanzhou University, Lanzhou, Gansu Province, People's Republic of China
| | - Quanlin Guan
- Gansu Province Key Laboratory of Gastrointestinal Diseases, The First Hospital of Lanzhou University, Lanzhou University, Lanzhou, Gansu Province, People's Republic of China
| |
Collapse
|
121
|
Bogutz AB, Brind'Amour J, Kobayashi H, Jensen KN, Nakabayashi K, Imai H, Lorincz MC, Lefebvre L. Evolution of imprinting via lineage-specific insertion of retroviral promoters. Nat Commun 2019; 10:5674. [PMID: 31831741 PMCID: PMC6908575 DOI: 10.1038/s41467-019-13662-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 11/14/2019] [Indexed: 01/09/2023] Open
Abstract
Imprinted genes are expressed from a single parental allele, with the other allele often silenced by DNA methylation (DNAme) established in the germline. While species-specific imprinted orthologues have been documented, the molecular mechanisms underlying the evolutionary switch from biallelic to imprinted expression are unknown. During mouse oogenesis, gametic differentially methylated regions (gDMRs) acquire DNAme in a transcription-guided manner. Here we show that oocyte transcription initiating in lineage-specific endogenous retroviruses (ERVs) is likely responsible for DNAme establishment at 4/6 mouse-specific and 17/110 human-specific imprinted gDMRs. The latter are divided into Catarrhini- or Hominoidea-specific gDMRs embedded within transcripts initiating in ERVs specific to these primate lineages. Strikingly, imprinting of the maternally methylated genes Impact and Slc38a4 was lost in the offspring of female mice harboring deletions of the relevant murine-specific ERVs upstream of these genes. Our work reveals an evolutionary mechanism whereby maternally silenced genes arise from biallelically expressed progenitors. Although many species-specific imprinted genes have been identified, how the evolutionary switch from biallelic to imprinted expression occurs is still unknown. Here authors find that lineage-specific ERVs active as oocyte promoters can induce de novo DNA methylation at gDMRs and imprinting.
Collapse
Affiliation(s)
- Aaron B Bogutz
- Department of Medical Genetics, Molecular Epigenetics Group, Life Sciences Institute, University of British Columbia, Vancouver, BC, V6T 1Z3, Canada
| | - Julie Brind'Amour
- Department of Medical Genetics, Molecular Epigenetics Group, Life Sciences Institute, University of British Columbia, Vancouver, BC, V6T 1Z3, Canada
| | - Hisato Kobayashi
- Department of Embryology, Nara Medical University, Kashihara, Nara, 634-8521, Japan
| | - Kristoffer N Jensen
- Department of Medical Genetics, Molecular Epigenetics Group, Life Sciences Institute, University of British Columbia, Vancouver, BC, V6T 1Z3, Canada
| | - Kazuhiko Nakabayashi
- Division of Developmental Genomics, Research Institute, National Center for Child Health and Development, Setagaya, Tokyo, 157-8535, Japan
| | - Hiroo Imai
- Molecular Biology Section, Department of Cellular and Molecular Biology, Primate Research Institute, Kyoto University, Inuyama, Aichi, 484-8506, Japan
| | - Matthew C Lorincz
- Department of Medical Genetics, Molecular Epigenetics Group, Life Sciences Institute, University of British Columbia, Vancouver, BC, V6T 1Z3, Canada.
| | - Louis Lefebvre
- Department of Medical Genetics, Molecular Epigenetics Group, Life Sciences Institute, University of British Columbia, Vancouver, BC, V6T 1Z3, Canada.
| |
Collapse
|
122
|
Tirnaz S, Batley J. DNA Methylation: Toward Crop Disease Resistance Improvement. TRENDS IN PLANT SCIENCE 2019; 24:1137-1150. [PMID: 31604599 DOI: 10.1016/j.tplants.2019.08.007] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 08/13/2019] [Accepted: 08/22/2019] [Indexed: 05/23/2023]
Abstract
Crop diseases, in conjunction with climate change, are a major threat to global crop production. DNA methylation is an epigenetic mark and is involved in plants' biological processes, including development, stress adaptation, and genome evolution. By providing a new source of variation, DNA methylation introduces novel direction to both scientists and breeders with its potential in disease resistance enhancement. Here, we discuss the impact of pathogen-induced DNA methylation modifications on a host's transcriptome reprogramming and genome stability, as part of the plant's defense mechanisms. We also highlight the knowledge gaps that need to be investigated for understanding the entire role of DNA methylation in plant pathogen interactions. This will ultimately assist breeders toward improving resistance and decreasing yield losses.
Collapse
Affiliation(s)
- Soodeh Tirnaz
- School of Biological Sciences, University of Western Australia, Perth, WA, 6009, Australia
| | - Jacqueline Batley
- School of Biological Sciences, University of Western Australia, Perth, WA, 6009, Australia.
| |
Collapse
|
123
|
Böck J, Remmele CW, Dittrich M, Müller T, Kondova I, Persengiev S, Bontrop RE, Ade CP, Kraus TFJ, Giese A, El Hajj N, Schneider E, Haaf T. Cell Type and Species-specific Patterns in Neuronal and Non-neuronal Methylomes of Human and Chimpanzee Cortices. Cereb Cortex 2019; 28:3724-3739. [PMID: 30085031 PMCID: PMC6132288 DOI: 10.1093/cercor/bhy180] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 07/13/2018] [Indexed: 12/04/2022] Open
Abstract
Epigenetic changes have likely contributed to the large size and enhanced cognitive abilities of the human brain which evolved within the last 2 million years after the human–chimpanzee split. Using reduced representation bisulfite sequencing, we have compared the methylomes of neuronal and non-neuronal cells from 3 human and 3 chimpanzee cortices. Differentially methylated regions (DMRs) with genome-wide significance were enriched in specific genomic regions. Intraspecific methylation differences between neuronal and non-neuronal cells were approximately 3 times more abundant than interspecific methylation differences between human and chimpanzee cell types. The vast majority (>90%) of human intraspecific DMRs (including DMRs in retrotransposons) were hypomethylated in neurons, compared with glia. Intraspecific DMRs were enriched in genes associated with different neuropsychiatric disorders. Interspecific DMRs were enriched in genes showing human-specific brain histone modifications. Human–chimpanzee methylation differences were much more frequent in non-neuronal cells (n. DMRs = 666) than in neurons (n. DMRs = 96). More than 95% of interspecific DMRs in glia were hypermethylated in humans. Although without an outgroup we cannot assign whether a change in methylation occurred in the human or chimpanzee lineage, our results are consistent with a wave of methylation affecting several hundred non-neuronal genes during human brain evolution.
Collapse
Affiliation(s)
- Julia Böck
- Institute of Human Genetics, Julius Maximilians University Würzburg, Würzburg, Germany
| | - Christian W Remmele
- Department of Bioinformatics, Julius Maximilians University Würzburg, Würzburg Germany
| | - Marcus Dittrich
- Institute of Human Genetics, Julius Maximilians University Würzburg, Würzburg, Germany.,Department of Bioinformatics, Julius Maximilians University Würzburg, Würzburg Germany
| | - Tobias Müller
- Department of Bioinformatics, Julius Maximilians University Würzburg, Würzburg Germany
| | - Ivanela Kondova
- Biomedical Primate Research Center, 2288 GJ Rijswijk, The Netherlands
| | | | - Ronald E Bontrop
- Biomedical Primate Research Center, 2288 GJ Rijswijk, The Netherlands
| | - Carsten P Ade
- Institute of Biochemistry and Molecular Biology, Julius Maximilians University Würzburg, Würzburg, Germany
| | - Theo F J Kraus
- Center for Neuropathology and Prion Research, Ludwig Maximilians University Munich, Munich, Germany
| | - Armin Giese
- Center for Neuropathology and Prion Research, Ludwig Maximilians University Munich, Munich, Germany
| | - Nady El Hajj
- Institute of Human Genetics, Julius Maximilians University Würzburg, Würzburg, Germany
| | - Eberhard Schneider
- Institute of Human Genetics, Julius Maximilians University Würzburg, Würzburg, Germany
| | - Thomas Haaf
- Institute of Human Genetics, Julius Maximilians University Würzburg, Würzburg, Germany
| |
Collapse
|
124
|
Li J, Chen N, Gong X. Prognostic implications of aberrantly expressed methylation‑driven genes in hepatocellular carcinoma: A study based on The Cancer Genome Atlas. Mol Med Rep 2019; 20:5304-5314. [PMID: 31661127 DOI: 10.3892/mmr.2019.10771] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 08/30/2019] [Indexed: 11/06/2022] Open
Abstract
RNA‑Sequencing and methylation data for hepatocellular carcinoma (HCC) were downloaded from The Cancer Genome Atlas (TCGA). The aberrantly expressed methylation‑driven genes in HCC and normal tissues were identified using the Limma package and the MethylMix algorithm. The Database for Annotation, Visualization and Integrated Discovery and ConsensusPathDB were used for Gene Ontology (GO) enrichment and pathway analysis. Univariate and multivariate Cox regression analyses were used to construct a prognostic risk model of HCC. Survival curve and receiver operating characteristic (ROC) curves were applied to evaluate the clinical utility of the risk model. A total of 238 methylation‑driven genes were successfully identified from cancer and normal tissues. GO enrichment analysis indicated that these genes functioned in the extracellular space, interfering with lipid metabolism in hepatocytes and regulating adaptive immune responses. In total, 14 relevant pathways were identified. The following prognostic risk model was generated: Risk score=CALML3 (degree of methylation) x (‑4.860) + CCNI2 x (2.071) + TNFRSF12A x (‑3.369) + IFITM1 x (1.203) + ENPP7P13 x (‑1.366) + DDT x (2.139) + RASAL2‑AS1 x (‑1.384) + ANKRD22 x (‑3.215). The median risk score (0.970) derived from this model was set as cutoff value for assigning patients to high‑ or low‑risk group. The 5‑year survival rate was 35.8% [95% confidence interval (CI)=27.1‑47.4%] in the high‑risk group and 61.7% (95% CI=51.4‑74.2%) in the low‑risk group (P<0.0001). The ROC curve showed an area under the curve of 0.742, indicating that this model is appropriate for predicting the survival rate of patients. Furthermore, the methylation and expression levels of two key genes, tumor necrosis factor superfamily member 12A and D‑dopachrome decarboxylase, were significantly associated with prognosis and were correlated with cg00510447, cg26808293, cg11060661 and cg16132339 methylation. In conclusion, a prognostic risk model for HCC is proposed based on the bioinformatic analysis of methylation‑driven genes. The findings of the present study may improve understanding of the pathogenesis and prognosis of HCC.
Collapse
Affiliation(s)
- Jinzhong Li
- Department of Gastroenterology, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong 510000, P.R. China
| | - Ning Chen
- Department of General Medicine, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong 510000, P.R. China
| | - Xiaobing Gong
- Department of Gastroenterology, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong 510000, P.R. China
| |
Collapse
|
125
|
Maierhofer A, Flunkert J, Oshima J, Martin GM, Poot M, Nanda I, Dittrich M, Müller T, Haaf T. Epigenetic signatures of Werner syndrome occur early in life and are distinct from normal epigenetic aging processes. Aging Cell 2019; 18:e12995. [PMID: 31259468 PMCID: PMC6718529 DOI: 10.1111/acel.12995] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 05/24/2019] [Accepted: 06/05/2019] [Indexed: 12/11/2022] Open
Abstract
Werner Syndrome (WS) is an adult-onset segmental progeroid syndrome. Bisulfite pyrosequencing of repetitive DNA families revealed comparable blood DNA methylation levels between classical (18 WRN-mutant) or atypical WS (3 LMNA-mutant and 3 POLD1-mutant) patients and age- and sex-matched controls. WS was not associated with either age-related accelerated global losses of ALU, LINE1, and α-satellite DNA methylations or gains of rDNA methylation. Single CpG methylation was analyzed with Infinium MethylationEPIC arrays. In a correspondence analysis, atypical WS samples clustered together with the controls and were clearly separated from classical WS, consistent with distinct epigenetic pathologies. In classical WS, we identified 659 differentially methylated regions (DMRs) comprising 3,656 CpG sites and 613 RefSeq genes. The top DMR was located in the HOXA4 promoter. Additional DMR genes included LMNA, POLD1, and 132 genes which have been reported to be differentially expressed in WRN-mutant/depleted cells. DMRs were enriched in genes with molecular functions linked to transcription factor activity and sequence-specific DNA binding to promoters transcribed by RNA polymerase II. We propose that transcriptional misregulation of downstream genes by the absence of WRN protein contributes to the variable premature aging phenotypes of WS. There were no CpG sites showing significant differences in DNA methylation changes with age between WS patients and controls. Genes with both WS- and age-related methylation changes exhibited a constant offset of methylation between WRN-mutant patients and controls across the entire analyzed age range. WS-specific epigenetic signatures occur early in life and do not simply reflect an acceleration of normal epigenetic aging processes.
Collapse
Affiliation(s)
- Anna Maierhofer
- Institute of Human Genetics Julius Maximilians University Würzburg Germany
| | - Julia Flunkert
- Institute of Human Genetics Julius Maximilians University Würzburg Germany
| | - Junko Oshima
- Department of Pathology University of Washington Seattle Washington USA
- Department of Clinical Cell Biology and Medicine, Graduate School of Medicine Chiba University Chiba Japan
| | - George M. Martin
- Department of Pathology University of Washington Seattle Washington USA
| | - Martin Poot
- Institute of Human Genetics Julius Maximilians University Würzburg Germany
| | - Indrajit Nanda
- Institute of Human Genetics Julius Maximilians University Würzburg Germany
| | - Marcus Dittrich
- Institute of Human Genetics Julius Maximilians University Würzburg Germany
- Department of Bioinformatics Julius Maximilians University Würzburg Germany
| | - Tobias Müller
- Department of Bioinformatics Julius Maximilians University Würzburg Germany
| | - Thomas Haaf
- Institute of Human Genetics Julius Maximilians University Würzburg Germany
| |
Collapse
|
126
|
Canli T. A model of human endogenous retrovirus (HERV) activation in mental health and illness. Med Hypotheses 2019; 133:109404. [PMID: 31557593 DOI: 10.1016/j.mehy.2019.109404] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 09/18/2019] [Indexed: 01/04/2023]
Abstract
Despite strong evidence for the heritability of major depressive disorder (MDD), efforts to identify causal genes have been disappointing. Furthermore, although there is strong support for life stress as a major predictor of MDD, there are also considerable individual differences in susceptibility and resilience that remain poorly understood. Efforts to identify specific gene-by-environment risk factors produced results that were initially encouraging, but that were not supported by later large-scale studies. Here I propose a novel mechanism that could address the "missing heritability" of MDD, the role of environmental risk factors, and individual differences in susceptibility and resilience. This mechanism focuses on a class of transposable elements, Human Endogenous Retroviruses (HERVs), which make up approximately 8% of the human genome as the result of ancient retroviral infections that entered mammalian germ lines throughout the course of evolution. My primary hypothesis is that exposure to either exogenous viruses or traumatic experiences can activate HERVs in the brain to cause depressive (and possibly other psychiatric) symptoms. My secondary hypothesis is that individual differences in vulnerability or resilience result from the balance of activated HERVs with pathogenic versus protective functions in the brain. Future research can test these hypotheses by analysis of postmortem human brain tissue from donors with known viral or trauma histories; animal studies manipulating HERV expression; cell culture studies examining regulatory mechanisms of HERV expression; and from brain imaging studies of individuals with known HERV-expression. Such research may reveal novel functions of HERVs in neural tissue and may lead to a new generation of psychiatric interventions designed to target aberrant HERV activation.
Collapse
MESH Headings
- Animals
- Brain/virology
- Cells, Cultured
- Cytokines/physiology
- Depressive Disorder, Major/etiology
- Depressive Disorder, Major/genetics
- Depressive Disorder, Major/immunology
- Depressive Disorder, Major/virology
- Disease Models, Animal
- Endogenous Retroviruses/genetics
- Endogenous Retroviruses/physiology
- Environmental Exposure
- Epigenesis, Genetic
- Gene Expression Regulation, Viral
- Gene-Environment Interaction
- Genes, Viral
- Humans
- Intercellular Signaling Peptides and Proteins/physiology
- Mice, Transgenic
- Models, Biological
- Models, Psychological
- Schizophrenia/pathology
- Schizophrenia/virology
- Stress, Psychological
- Terminal Repeat Sequences/genetics
- Virus Activation
- Virus Diseases/complications
- Virus Diseases/psychology
Collapse
Affiliation(s)
- Turhan Canli
- Departments of Psychology and Psychiatry, Stony Brook University, Stony Brook, NY 11794-2500, USA.
| |
Collapse
|
127
|
Cajuso T, Sulo P, Tanskanen T, Katainen R, Taira A, Hänninen UA, Kondelin J, Forsström L, Välimäki N, Aavikko M, Kaasinen E, Ristimäki A, Koskensalo S, Lepistö A, Renkonen-Sinisalo L, Seppälä T, Kuopio T, Böhm J, Mecklin JP, Kilpivaara O, Pitkänen E, Palin K, Aaltonen LA. Retrotransposon insertions can initiate colorectal cancer and are associated with poor survival. Nat Commun 2019; 10:4022. [PMID: 31492840 PMCID: PMC6731219 DOI: 10.1038/s41467-019-11770-0] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 07/31/2019] [Indexed: 12/20/2022] Open
Abstract
Genomic instability pathways in colorectal cancer (CRC) have been extensively studied, but the role of retrotransposition in colorectal carcinogenesis remains poorly understood. Although retrotransposons are usually repressed, they become active in several human cancers, in particular those of the gastrointestinal tract. Here we characterize retrotransposon insertions in 202 colorectal tumor whole genomes and investigate their associations with molecular and clinical characteristics. We find highly variable retrotransposon activity among tumors and identify recurrent insertions in 15 known cancer genes. In approximately 1% of the cases we identify insertions in APC, likely to be tumor-initiating events. Insertions are positively associated with the CpG island methylator phenotype and the genomic fraction of allelic imbalance. Clinically, high number of insertions is independently associated with poor disease-specific survival. Retrotransposons are usually dormant in healthy tissue, but become activated during malignancy. Here, in colorectal cancer, Cajuso et al. show that retrotransposon activity associates with clinical features of the disease.
Collapse
Affiliation(s)
- Tatiana Cajuso
- Applied Tumor Genomics Research Program, Faculty of Medicine University of Helsinki, Biomedicum Helsinki, PO Box 63, (Haartmaninkatu 8), FI-00014, Helsinki, Finland.,Department of Medical and Clinical Genetics, Medicum, University of Helsinki, Biomedicum Helsinki, PO Box 63, (Haartmaninkatu 8), FI-00014, Helsinki, Finland
| | - Päivi Sulo
- Applied Tumor Genomics Research Program, Faculty of Medicine University of Helsinki, Biomedicum Helsinki, PO Box 63, (Haartmaninkatu 8), FI-00014, Helsinki, Finland.,Department of Medical and Clinical Genetics, Medicum, University of Helsinki, Biomedicum Helsinki, PO Box 63, (Haartmaninkatu 8), FI-00014, Helsinki, Finland
| | - Tomas Tanskanen
- Applied Tumor Genomics Research Program, Faculty of Medicine University of Helsinki, Biomedicum Helsinki, PO Box 63, (Haartmaninkatu 8), FI-00014, Helsinki, Finland.,Department of Medical and Clinical Genetics, Medicum, University of Helsinki, Biomedicum Helsinki, PO Box 63, (Haartmaninkatu 8), FI-00014, Helsinki, Finland
| | - Riku Katainen
- Applied Tumor Genomics Research Program, Faculty of Medicine University of Helsinki, Biomedicum Helsinki, PO Box 63, (Haartmaninkatu 8), FI-00014, Helsinki, Finland.,Department of Medical and Clinical Genetics, Medicum, University of Helsinki, Biomedicum Helsinki, PO Box 63, (Haartmaninkatu 8), FI-00014, Helsinki, Finland
| | - Aurora Taira
- Applied Tumor Genomics Research Program, Faculty of Medicine University of Helsinki, Biomedicum Helsinki, PO Box 63, (Haartmaninkatu 8), FI-00014, Helsinki, Finland.,Department of Medical and Clinical Genetics, Medicum, University of Helsinki, Biomedicum Helsinki, PO Box 63, (Haartmaninkatu 8), FI-00014, Helsinki, Finland
| | - Ulrika A Hänninen
- Applied Tumor Genomics Research Program, Faculty of Medicine University of Helsinki, Biomedicum Helsinki, PO Box 63, (Haartmaninkatu 8), FI-00014, Helsinki, Finland.,Department of Medical and Clinical Genetics, Medicum, University of Helsinki, Biomedicum Helsinki, PO Box 63, (Haartmaninkatu 8), FI-00014, Helsinki, Finland
| | - Johanna Kondelin
- Applied Tumor Genomics Research Program, Faculty of Medicine University of Helsinki, Biomedicum Helsinki, PO Box 63, (Haartmaninkatu 8), FI-00014, Helsinki, Finland.,Department of Medical and Clinical Genetics, Medicum, University of Helsinki, Biomedicum Helsinki, PO Box 63, (Haartmaninkatu 8), FI-00014, Helsinki, Finland
| | - Linda Forsström
- Applied Tumor Genomics Research Program, Faculty of Medicine University of Helsinki, Biomedicum Helsinki, PO Box 63, (Haartmaninkatu 8), FI-00014, Helsinki, Finland.,Department of Medical and Clinical Genetics, Medicum, University of Helsinki, Biomedicum Helsinki, PO Box 63, (Haartmaninkatu 8), FI-00014, Helsinki, Finland
| | - Niko Välimäki
- Applied Tumor Genomics Research Program, Faculty of Medicine University of Helsinki, Biomedicum Helsinki, PO Box 63, (Haartmaninkatu 8), FI-00014, Helsinki, Finland.,Department of Medical and Clinical Genetics, Medicum, University of Helsinki, Biomedicum Helsinki, PO Box 63, (Haartmaninkatu 8), FI-00014, Helsinki, Finland
| | - Mervi Aavikko
- Applied Tumor Genomics Research Program, Faculty of Medicine University of Helsinki, Biomedicum Helsinki, PO Box 63, (Haartmaninkatu 8), FI-00014, Helsinki, Finland.,Department of Medical and Clinical Genetics, Medicum, University of Helsinki, Biomedicum Helsinki, PO Box 63, (Haartmaninkatu 8), FI-00014, Helsinki, Finland
| | - Eevi Kaasinen
- Applied Tumor Genomics Research Program, Faculty of Medicine University of Helsinki, Biomedicum Helsinki, PO Box 63, (Haartmaninkatu 8), FI-00014, Helsinki, Finland.,Department of Medical and Clinical Genetics, Medicum, University of Helsinki, Biomedicum Helsinki, PO Box 63, (Haartmaninkatu 8), FI-00014, Helsinki, Finland
| | - Ari Ristimäki
- Applied Tumor Genomics Research Program, Faculty of Medicine University of Helsinki, Biomedicum Helsinki, PO Box 63, (Haartmaninkatu 8), FI-00014, Helsinki, Finland.,Department of Pathology, HUSLAB, University of Helsinki and Helsinki University Hospital, (Haartmaninkatu 3), FI-00290, Helsinki, Finland
| | - Selja Koskensalo
- Department of Gastrointestinal Surgery, Helsinki University Hospital, University of Helsinki, (Haartmaninkatu 4), FI-00290, Helsinki, Finland
| | - Anna Lepistö
- Department of Gastrointestinal Surgery, Helsinki University Hospital, University of Helsinki, (Haartmaninkatu 4), FI-00290, Helsinki, Finland
| | - Laura Renkonen-Sinisalo
- Department of Gastrointestinal Surgery, Helsinki University Hospital, University of Helsinki, (Haartmaninkatu 4), FI-00290, Helsinki, Finland
| | - Toni Seppälä
- Department of Gastrointestinal Surgery, Helsinki University Hospital, University of Helsinki, (Haartmaninkatu 4), FI-00290, Helsinki, Finland
| | - Teijo Kuopio
- Biological and Environmental Science, University of Jyväskylä, PO Box 35, (Seminaarinkatu 15), FI-40014, Jyväskylä, Finland.,Department of Pathology, Central Finland Health Care District, (Keskussairaalantie 19), FI-40620 Jyväskylä, Finland
| | - Jan Böhm
- Department of Pathology, Central Finland Health Care District, (Keskussairaalantie 19), FI-40620 Jyväskylä, Finland
| | - Jukka-Pekka Mecklin
- Department of Surgery, Jyväskylä Central Hospital, (Keskussairaalantie 19), FI-40620, Jyväskylä, Finland.,Department of Health Sciences, Faculty of Sport and Health Sciences, University of Jyväskylä, PO Box 35, (Seminaarinkatu 15), FI-40014, Jyväskylä, Finland
| | - Outi Kilpivaara
- Applied Tumor Genomics Research Program, Faculty of Medicine University of Helsinki, Biomedicum Helsinki, PO Box 63, (Haartmaninkatu 8), FI-00014, Helsinki, Finland.,Department of Medical and Clinical Genetics, Medicum, University of Helsinki, Biomedicum Helsinki, PO Box 63, (Haartmaninkatu 8), FI-00014, Helsinki, Finland
| | - Esa Pitkänen
- Applied Tumor Genomics Research Program, Faculty of Medicine University of Helsinki, Biomedicum Helsinki, PO Box 63, (Haartmaninkatu 8), FI-00014, Helsinki, Finland.,Department of Medical and Clinical Genetics, Medicum, University of Helsinki, Biomedicum Helsinki, PO Box 63, (Haartmaninkatu 8), FI-00014, Helsinki, Finland
| | - Kimmo Palin
- Applied Tumor Genomics Research Program, Faculty of Medicine University of Helsinki, Biomedicum Helsinki, PO Box 63, (Haartmaninkatu 8), FI-00014, Helsinki, Finland.,Department of Medical and Clinical Genetics, Medicum, University of Helsinki, Biomedicum Helsinki, PO Box 63, (Haartmaninkatu 8), FI-00014, Helsinki, Finland
| | - Lauri A Aaltonen
- Applied Tumor Genomics Research Program, Faculty of Medicine University of Helsinki, Biomedicum Helsinki, PO Box 63, (Haartmaninkatu 8), FI-00014, Helsinki, Finland. .,Department of Medical and Clinical Genetics, Medicum, University of Helsinki, Biomedicum Helsinki, PO Box 63, (Haartmaninkatu 8), FI-00014, Helsinki, Finland.
| |
Collapse
|
128
|
Noshay JM, Anderson SN, Zhou P, Ji L, Ricci W, Lu Z, Stitzer MC, Crisp PA, Hirsch CN, Zhang X, Schmitz RJ, Springer NM. Monitoring the interplay between transposable element families and DNA methylation in maize. PLoS Genet 2019; 15:e1008291. [PMID: 31498837 PMCID: PMC6752859 DOI: 10.1371/journal.pgen.1008291] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 09/19/2019] [Accepted: 07/05/2019] [Indexed: 12/15/2022] Open
Abstract
DNA methylation and epigenetic silencing play important roles in the regulation of transposable elements (TEs) in many eukaryotic genomes. A majority of the maize genome is derived from TEs that can be classified into different orders and families based on their mechanism of transposition and sequence similarity, respectively. TEs themselves are highly methylated and it can be tempting to view them as a single uniform group. However, the analysis of DNA methylation profiles in flanking regions provides evidence for distinct groups of chromatin properties at different TE families. These differences among TE families are reproducible in different tissues and different inbred lines. TE families with varying levels of DNA methylation in flanking regions also show distinct patterns of chromatin accessibility and modifications within the TEs. The differences in the patterns of DNA methylation flanking TE families arise from a combination of non-random insertion preferences of TE families, changes in DNA methylation triggered by the insertion of the TE and subsequent selection pressure. A set of nearly 70,000 TE polymorphisms among four assembled maize genomes were used to monitor the level of DNA methylation at haplotypes with and without the TE insertions. In many cases, TE families with high levels of DNA methylation in flanking sequence are enriched for insertions into highly methylated regions. The majority of the >2,500 TE insertions into unmethylated regions result in changes in DNA methylation in haplotypes with the TE, suggesting the widespread potential for TE insertions to condition altered methylation in conserved regions of the genome. This study highlights the interplay between TEs and the methylome of a major crop species.
Collapse
Affiliation(s)
- Jaclyn M. Noshay
- Department of Plant and Microbial Biology, University of Minnesota, St. Paul MN, United States of America
| | - Sarah N. Anderson
- Department of Plant and Microbial Biology, University of Minnesota, St. Paul MN, United States of America
| | - Peng Zhou
- Department of Plant and Microbial Biology, University of Minnesota, St. Paul MN, United States of America
| | - Lexiang Ji
- Institute of Bioinformatics, University of Georgia, Athens GA, United States of America
| | - William Ricci
- Department of Plant Biology, University of Georgia, Athens GA, United States of America
| | - Zefu Lu
- Department of Genetics, University of Georgia, Athens GA, United States of America
| | - Michelle C. Stitzer
- Department of Plant Sciences, University of California Davis, Davis CA, United States of America
| | - Peter A. Crisp
- Department of Plant and Microbial Biology, University of Minnesota, St. Paul MN, United States of America
| | - Candice N. Hirsch
- Department of Agronomy and Plant Genetics, University of Minnesota, St. Paul MN, United States of America
| | - Xiaoyu Zhang
- Department of Plant Biology, University of Georgia, Athens GA, United States of America
| | - Robert J. Schmitz
- Department of Genetics, University of Georgia, Athens GA, United States of America
| | - Nathan M. Springer
- Department of Plant and Microbial Biology, University of Minnesota, St. Paul MN, United States of America
| |
Collapse
|
129
|
Abstract
Transposable elements (TEs) are mobile DNA sequences that colonize genomes and threaten genome integrity. As a result, several mechanisms appear to have emerged during eukaryotic evolution to suppress TE activity. However, TEs are ubiquitous and account for a prominent fraction of most eukaryotic genomes. We argue that the evolutionary success of TEs cannot be explained solely by evasion from host control mechanisms. Rather, some TEs have evolved commensal and even mutualistic strategies that mitigate the cost of their propagation. These coevolutionary processes promote the emergence of complex cellular activities, which in turn pave the way for cooption of TE sequences for organismal function.
Collapse
Affiliation(s)
- Rachel L Cosby
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14853, USA
| | - Ni-Chen Chang
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14853, USA
| | - Cédric Feschotte
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14853, USA
| |
Collapse
|
130
|
Scelfo A, Fachinetti D. Keeping the Centromere under Control: A Promising Role for DNA Methylation. Cells 2019; 8:cells8080912. [PMID: 31426433 PMCID: PMC6721688 DOI: 10.3390/cells8080912] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2019] [Revised: 08/06/2019] [Accepted: 08/15/2019] [Indexed: 01/22/2023] Open
Abstract
In order to maintain cell and organism homeostasis, the genetic material has to be faithfully and equally inherited through cell divisions while preserving its integrity. Centromeres play an essential task in this process; they are special sites on chromosomes where kinetochores form on repetitive DNA sequences to enable accurate chromosome segregation. Recent evidence suggests that centromeric DNA sequences, and epigenetic regulation of centromeres, have important roles in centromere physiology. In particular, DNA methylation is abundant at the centromere, and aberrant DNA methylation, observed in certain tumors, has been correlated to aneuploidy and genomic instability. In this review, we evaluate past and current insights on the relationship between centromere function and the DNA methylation pattern of its underlying sequences.
Collapse
Affiliation(s)
- Andrea Scelfo
- Institut Curie, PSL Research University, CNRS, UMR144, 26 rue d'Ulm, 75005 Paris, France.
| | - Daniele Fachinetti
- Institut Curie, PSL Research University, CNRS, UMR144, 26 rue d'Ulm, 75005 Paris, France.
| |
Collapse
|
131
|
The diverse roles of DNA methylation in mammalian development and disease. Nat Rev Mol Cell Biol 2019; 20:590-607. [PMID: 31399642 DOI: 10.1038/s41580-019-0159-6] [Citation(s) in RCA: 1079] [Impact Index Per Article: 215.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/08/2019] [Indexed: 12/22/2022]
Abstract
DNA methylation is of paramount importance for mammalian embryonic development. DNA methylation has numerous functions: it is implicated in the repression of transposons and genes, but is also associated with actively transcribed gene bodies and, in some cases, with gene activation per se. In recent years, sensitive technologies have been developed that allow the interrogation of DNA methylation patterns from a small number of cells. The use of these technologies has greatly improved our knowledge of DNA methylation dynamics and heterogeneity in embryos and in specific tissues. Combined with genetic analyses, it is increasingly apparent that regulation of DNA methylation erasure and (re-)establishment varies considerably between different developmental stages. In this Review, we discuss the mechanisms and functions of DNA methylation and demethylation in both mice and humans at CpG-rich promoters, gene bodies and transposable elements. We highlight the dynamic erasure and re-establishment of DNA methylation in embryonic, germline and somatic cell development. Finally, we provide insights into DNA methylation gained from studying genetic diseases.
Collapse
|
132
|
Pfeifer GP, Szabó PE, Song J. Protein Interactions at Oxidized 5-Methylcytosine Bases. J Mol Biol 2019:S0022-2836(19)30501-7. [PMID: 31401118 DOI: 10.1016/j.jmb.2019.07.039] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 07/31/2019] [Indexed: 12/19/2022]
Abstract
5-Methylcytosine (5mC), the major modified DNA base in mammalian cells, can be oxidized enzymatically to 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC), and 5-carboxylcytosine (5caC) by the Ten-Eleven-Translocation (TET) family of proteins. Whereas 5fC and 5caC are recognized and removed by base excision repair proteins, the 5hmC base accumulates to substantial levels in certain cell types such as brain-derived neurons and is viewed as a relatively stable DNA base. As such, the existence of "reader" proteins that recognize 5hmC would be a logical assumption, and various searches have been undertaken to identify proteins that specifically bind to 5hmC and the other oxidized 5mC bases. However, the existence of definitive 5hmC "readers" has remained unclear and proteins interacting specifically with 5fC or 5caC are also very few. On the other hand, 5hmC is incapable of interacting with a number of proteins that recognize 5mC at CpG sequences, suggesting that 5hmC is an anti-reader modification that may serve to displace 5mC readers from DNA. In this review article, we discuss candidate proteins that may interact with oxidized 5mC bases.
Collapse
Affiliation(s)
- Gerd P Pfeifer
- Center for Epigenetics, Van Andel Institute, Grand Rapids, MI 49503, USA.
| | - Piroska E Szabó
- Center for Epigenetics, Van Andel Institute, Grand Rapids, MI 49503, USA
| | - Jikui Song
- Department of Biochemistry, University of California Riverside, Riverside, CA 92521, USA
| |
Collapse
|
133
|
Schmitz RJ, Lewis ZA, Goll MG. DNA Methylation: Shared and Divergent Features across Eukaryotes. Trends Genet 2019; 35:818-827. [PMID: 31399242 DOI: 10.1016/j.tig.2019.07.007] [Citation(s) in RCA: 121] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 07/01/2019] [Accepted: 07/15/2019] [Indexed: 02/02/2023]
Abstract
Chemical modification of nucleotide bases in DNA provides one mechanism for conveying information in addition to the genetic code. 5-methylcytosine (5mC) represents the most common chemically modified base in eukaryotic genomes. Sometimes referred to simply as DNA methylation, in eukaryotes 5mC is most prevalent at CpG dinucleotides and is frequently associated with transcriptional repression of transposable elements. However, 5mC levels and distributions are variable across phylogenies, and emerging evidence suggests that the functions of DNA methylation may be more diverse and complex than was previously appreciated. We summarize the current understanding of DNA methylation profiles and functions in different eukaryotic lineages.
Collapse
Affiliation(s)
- Robert J Schmitz
- Department of Genetics, University of Georgia, Athens, GA 30602, USA
| | - Zachary A Lewis
- Department of Microbiology, University of Georgia, Athens, GA 30602, USA
| | - Mary G Goll
- Department of Genetics, University of Georgia, Athens, GA 30602, USA.
| |
Collapse
|
134
|
Human placental methylome in the interplay of adverse placental health, environmental exposure, and pregnancy outcome. PLoS Genet 2019; 15:e1008236. [PMID: 31369552 PMCID: PMC6675049 DOI: 10.1371/journal.pgen.1008236] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The placenta is the interface between maternal and fetal circulations, integrating maternal and fetal signals to selectively regulate nutrient, gas, and waste exchange, as well as secrete hormones. In turn, the placenta helps create the in utero environment and control fetal growth and development. The unique epigenetic profile of the human placenta likely reflects its early developmental separation from the fetus proper and its role in mediating maternal–fetal exchange that leaves it open to a range of exogenous exposures in the maternal circulation. In this review, we cover recent advances in DNA methylation in the context of placental function and development, as well as the interaction between the pregnancy and the environment.
Collapse
|
135
|
Abstract
Maintenance of genome stability requires control over the expression of transposable elements (TEs), whose activity can have substantial deleterious effects on the host. Chemical modification of DNA is a commonly used strategy to achieve this, and it has long been argued that the emergence of 5-methylcytosine (5mC) in many species was driven by the requirement to silence TEs. Potential roles in TE regulation have also been suggested for other DNA modifications, such as N6-methyladenine and oxidation derivatives of 5mC, although the underlying mechanistic relationships are poorly understood. Here, we discuss current evidence implicating DNA modifications and DNA-modifying enzymes in TE regulation across different species.
Collapse
Affiliation(s)
- Özgen Deniz
- Blizard Institute, Barts and The London School of Medicine and Dentistry, QMUL, London, UK
| | - Jennifer M Frost
- Blizard Institute, Barts and The London School of Medicine and Dentistry, QMUL, London, UK
| | - Miguel R Branco
- Blizard Institute, Barts and The London School of Medicine and Dentistry, QMUL, London, UK.
| |
Collapse
|
136
|
Jönsson ME, Ludvik Brattås P, Gustafsson C, Petri R, Yudovich D, Pircs K, Verschuere S, Madsen S, Hansson J, Larsson J, Månsson R, Meissner A, Jakobsson J. Activation of neuronal genes via LINE-1 elements upon global DNA demethylation in human neural progenitors. Nat Commun 2019; 10:3182. [PMID: 31320637 PMCID: PMC6639357 DOI: 10.1038/s41467-019-11150-8] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 06/20/2019] [Indexed: 01/14/2023] Open
Abstract
DNA methylation contributes to the maintenance of genomic integrity in somatic cells, in part through the silencing of transposable elements. In this study, we use CRISPR-Cas9 technology to delete DNMT1, the DNA methyltransferase key for DNA methylation maintenance, in human neural progenitor cells (hNPCs). We observe that inactivation of DNMT1 in hNPCs results in viable, proliferating cells despite a global loss of DNA CpG-methylation. DNA demethylation leads to specific transcriptional activation and chromatin remodeling of evolutionarily young, hominoid-specific LINE-1 elements (L1s), while older L1s and other classes of transposable elements remain silent. The activated L1s act as alternative promoters for many protein-coding genes involved in neuronal functions, revealing a hominoid-specific L1-based transcriptional network controlled by DNA methylation that influences neuronal protein-coding genes. Our results provide mechanistic insight into the role of DNA methylation in silencing transposable elements in somatic human cells, as well as further implicating L1s in human brain development and disease. DNA methylation plays an important role in silencing transposable elements. Here the authors find that loss of DNMT1 and DNA methylation leads to transcriptional activation and chromatin remodelling of evolutionarily young—hominoid-specific —LINE-1 elements which then act as alternative promoters for neuronal genes.
Collapse
Affiliation(s)
- Marie E Jönsson
- Wallenberg Neuroscience Center and Lund Stem Cell Center, Laboratory of Molecular Neurogenetics, Department of Experimental Medical Science, BMC A11, Lund University, 221 84, Lund, Sweden
| | - Per Ludvik Brattås
- Wallenberg Neuroscience Center and Lund Stem Cell Center, Laboratory of Molecular Neurogenetics, Department of Experimental Medical Science, BMC A11, Lund University, 221 84, Lund, Sweden
| | - Charlotte Gustafsson
- Center for Hematology and Regenerative Medicine Huddinge, Karolinska Institute, 141 52, Stockholm, Sweden
| | - Rebecca Petri
- Wallenberg Neuroscience Center and Lund Stem Cell Center, Laboratory of Molecular Neurogenetics, Department of Experimental Medical Science, BMC A11, Lund University, 221 84, Lund, Sweden
| | - David Yudovich
- Division of Molecular Medicine and Gene Therapy, Department of Laboratory Medicine and Lund Stem Cell Center, BMC A12, Lund University, 221 84, Lund, Sweden
| | - Karolina Pircs
- Wallenberg Neuroscience Center and Lund Stem Cell Center, Laboratory of Molecular Neurogenetics, Department of Experimental Medical Science, BMC A11, Lund University, 221 84, Lund, Sweden
| | - Shana Verschuere
- Wallenberg Neuroscience Center and Lund Stem Cell Center, Laboratory of Molecular Neurogenetics, Department of Experimental Medical Science, BMC A11, Lund University, 221 84, Lund, Sweden
| | - Sofia Madsen
- Wallenberg Neuroscience Center and Lund Stem Cell Center, Laboratory of Molecular Neurogenetics, Department of Experimental Medical Science, BMC A11, Lund University, 221 84, Lund, Sweden
| | - Jenny Hansson
- Laboratory of Proteomic Hematology, Department of Laboratory Medicine and Lund Stem Cell Center, BMC B12, Lund University, 221 84, Lund, Sweden
| | - Jonas Larsson
- Division of Molecular Medicine and Gene Therapy, Department of Laboratory Medicine and Lund Stem Cell Center, BMC A12, Lund University, 221 84, Lund, Sweden
| | - Robert Månsson
- Center for Hematology and Regenerative Medicine Huddinge, Karolinska Institute, 141 52, Stockholm, Sweden
| | - Alexander Meissner
- Department of Genome Regulation, Max Planck Institute for Molecular Genetics, 14195, Berlin, Germany
| | - Johan Jakobsson
- Wallenberg Neuroscience Center and Lund Stem Cell Center, Laboratory of Molecular Neurogenetics, Department of Experimental Medical Science, BMC A11, Lund University, 221 84, Lund, Sweden.
| |
Collapse
|
137
|
Wang S, Zhang C, Hasson D, Desai A, SenBanerjee S, Magnani E, Ukomadu C, Lujambio A, Bernstein E, Sadler KC. Epigenetic Compensation Promotes Liver Regeneration. Dev Cell 2019; 50:43-56.e6. [PMID: 31231040 PMCID: PMC6615735 DOI: 10.1016/j.devcel.2019.05.034] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 04/02/2019] [Accepted: 05/16/2019] [Indexed: 12/19/2022]
Abstract
Two major functions of the epigenome are to regulate gene expression and to suppress transposons. It is unclear how these functions are balanced during physiological challenges requiring tissue regeneration, where exquisite coordination of gene expression is essential. Transcriptomic analysis of seven time points following partial hepatectomy identified the epigenetic regulator UHRF1, which is essential for DNA methylation, as dynamically expressed during liver regeneration in mice. UHRF1 deletion in hepatocytes (Uhrf1HepKO) caused genome-wide DNA hypomethylation but, surprisingly, had no measurable effect on gene or transposon expression or liver homeostasis. Partial hepatectomy of Uhrf1HepKO livers resulted in early and sustained activation of proregenerative genes and enhanced liver regeneration. This was attributed to redistribution of H3K27me3 from promoters to transposons, effectively silencing them and, consequently, alleviating repression of liver regeneration genes, priming them for expression in Uhrf1HepKO livers. Thus, epigenetic compensation safeguards the genome against transposon activation, indirectly affecting gene regulation.
Collapse
Affiliation(s)
- Shuang Wang
- Department of Medicine/Division of Liver Diseases, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Chi Zhang
- Program in Biology, New York University Abu Dhabi, Abu Dhabi, P.O. Box 129188, United Arab Emirates
| | - Dan Hasson
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Anal Desai
- Division of Gastroenterology, Department of Medicine, Brigham and Women's Hospital, Boston, MA 02115, USA
| | - Sucharita SenBanerjee
- Division of Gastroenterology, Department of Medicine, Brigham and Women's Hospital, Boston, MA 02115, USA; College of Arts and Sciences, Wentworth Institute of Technology, 504 Parker St., Boston, MA 02115, USA
| | - Elena Magnani
- Program in Biology, New York University Abu Dhabi, Abu Dhabi, P.O. Box 129188, United Arab Emirates
| | - Chinweike Ukomadu
- Division of Gastroenterology, Department of Medicine, Brigham and Women's Hospital, Boston, MA 02115, USA
| | - Amaia Lujambio
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Liver Cancer Program, Division of Liver Diseases, Department of Medicine, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Precision Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Emily Bernstein
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Kirsten C Sadler
- Department of Medicine/Division of Liver Diseases, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Program in Biology, New York University Abu Dhabi, Abu Dhabi, P.O. Box 129188, United Arab Emirates.
| |
Collapse
|
138
|
Bourgeois Y, Boissinot S. On the Population Dynamics of Junk: A Review on the Population Genomics of Transposable Elements. Genes (Basel) 2019; 10:genes10060419. [PMID: 31151307 PMCID: PMC6627506 DOI: 10.3390/genes10060419] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 05/05/2019] [Accepted: 05/21/2019] [Indexed: 01/18/2023] Open
Abstract
Transposable elements (TEs) play an important role in shaping genomic organization and structure, and may cause dramatic changes in phenotypes. Despite the genetic load they may impose on their host and their importance in microevolutionary processes such as adaptation and speciation, the number of population genetics studies focused on TEs has been rather limited so far compared to single nucleotide polymorphisms (SNPs). Here, we review the current knowledge about the dynamics of transposable elements at recent evolutionary time scales, and discuss the mechanisms that condition their abundance and frequency. We first discuss non-adaptive mechanisms such as purifying selection and the variable rates of transposition and elimination, and then focus on positive and balancing selection, to finally conclude on the potential role of TEs in causing genomic incompatibilities and eventually speciation. We also suggest possible ways to better model TEs dynamics in a population genomics context by incorporating recent advances in TEs into the rich information provided by SNPs about the demography, selection, and intrinsic properties of genomes.
Collapse
Affiliation(s)
- Yann Bourgeois
- New York University Abu Dhabi, P.O. 129188, Saadiyat Island, Abu Dhabi, United Arab Emirates.
| | - Stéphane Boissinot
- New York University Abu Dhabi, P.O. 129188, Saadiyat Island, Abu Dhabi, United Arab Emirates.
| |
Collapse
|
139
|
Bar S, Benvenisty N. Epigenetic aberrations in human pluripotent stem cells. EMBO J 2019; 38:embj.2018101033. [PMID: 31088843 DOI: 10.15252/embj.2018101033] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 03/13/2019] [Accepted: 03/15/2019] [Indexed: 12/14/2022] Open
Abstract
Human pluripotent stem cells (hPSCs) are being increasingly utilized worldwide in investigating human development, and modeling and discovering therapies for a wide range of diseases as well as a source for cellular therapy. Yet, since the first isolation of human embryonic stem cells (hESCs) 20 years ago, followed by the successful reprogramming of human-induced pluripotent stem cells (hiPSCs) 10 years later, various studies shed light on abnormalities that sometimes accumulate in these cells in vitro Whereas genetic aberrations are well documented, epigenetic alterations are not as thoroughly discussed. In this review, we highlight frequent epigenetic aberrations found in hPSCs, including alterations in DNA methylation patterns, parental imprinting, and X chromosome inactivation. We discuss the potential origins of these abnormalities in hESCs and hiPSCs, survey the different methods for detecting them, and elaborate on their potential consequences for the different utilities of hPSCs.
Collapse
Affiliation(s)
- Shiran Bar
- Department of Genetics, The Azrieli Center for Stem Cells and Genetic Research, Silberman Institute of Life Sciences, The Hebrew University, Jerusalem, Israel
| | - Nissim Benvenisty
- Department of Genetics, The Azrieli Center for Stem Cells and Genetic Research, Silberman Institute of Life Sciences, The Hebrew University, Jerusalem, Israel
| |
Collapse
|
140
|
Pan-cancer genomic analysis links 3'UTR DNA methylation with increased gene expression in T cells. EBioMedicine 2019; 43:127-137. [PMID: 31056473 PMCID: PMC6558231 DOI: 10.1016/j.ebiom.2019.04.045] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 04/09/2019] [Accepted: 04/23/2019] [Indexed: 01/12/2023] Open
Abstract
Background Investigations into the function of non-promoter DNA methylation have yielded new insights into the epigenetic regulation of gene expression. However, integrated genome-wide non-promoter DNA methylation and gene expression analyses across a wide number of tumour types and corresponding normal tissues have not been performed. Methods To investigate the impact of non-promoter DNA methylation on cancer pathogenesis, we performed a large-scale analysis of gene expression and DNA methylation profiles, finding enrichment in the 3’UTR DNA methylation positively correlated with gene expression. Filtering for genes in which 3’UTR DNA methylation strongly correlated with gene expression yielded a list of genes enriched for functions involving T cell activation. Findings The important immune checkpoint gene Havcr2 showed a substantial increase in 3’UTR DNA methylation upon T cell activation and subsequent upregulation of gene expression in mice. Furthermore, this increase in Havcr2 gene expression was abrogated by treatment with decitabine. Interpretation These findings indicate that the 3’UTR is a functionally relevant DNA methylation site. Additionally, we show a potential novel mechanism of HAVCR2 regulation in T cells, providing new insights for modulating immune checkpoint blockade.
Collapse
|
141
|
Jiang JC, Upton KR. Human transposons are an abundant supply of transcription factor binding sites and promoter activities in breast cancer cell lines. Mob DNA 2019; 10:16. [PMID: 31061680 PMCID: PMC6486989 DOI: 10.1186/s13100-019-0158-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Accepted: 04/01/2019] [Indexed: 12/22/2022] Open
Abstract
Background Transposable elements (TE) are commonly regarded as “junk DNA” with no apparent regulatory roles in the human genome. However, a growing body of evidence demonstrates that some TEs exhibit regulatory activities in a range of biological pathways and diseases, with notable examples in bile metabolism and innate immunity. TEs are typically suppressed by epigenetic modifications in healthy somatic tissues, which prevents both undesirable effects of insertional mutagenesis, and also unwanted gene activation. Interestingly, TEs are widely reported to be dysregulated in epithelial cancers, and while much attention has been paid to their effects on genome instability, relatively little has been reported on their effects on gene regulation. Here, we investigated the contribution of TEs to the transcriptional regulation in breast cancer cell lines. Results We found that a subset of TE subfamilies were enriched in oncogenic transcription factor binding sites and also harboured histone marks associated with active transcription, raising the possibility of these subfamilies playing a broad role in breast cancer transcriptional regulation. To directly assess promoter activity in triple negative breast cancer cell lines, we identified four breast cancer-associated genes with putative TE-derived promoters. TE deletion confirmed a contribution to promoter activity in all cases, and for two examples the promoter activity was almost completely contained within the TE. Conclusions Our findings demonstrate that TEs provide abundant oncogenic transcription factor binding sites in breast cancer and that individual TEs contain substantial promoter activity. Our findings provide further evidence for transcriptional regulation of human genes through TE exaptation by demonstrating the regulatory potential of TEs in multiple breast cancer cell lines. Electronic supplementary material The online version of this article (10.1186/s13100-019-0158-3) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Jiayue-Clara Jiang
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD 4072 Australia
| | - Kyle R Upton
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD 4072 Australia
| |
Collapse
|
142
|
Jeong H, Arif B, Caetano-Anollés G, Kim KM, Nasir A. Horizontal gene transfer in human-associated microorganisms inferred by phylogenetic reconstruction and reconciliation. Sci Rep 2019; 9:5953. [PMID: 30976019 PMCID: PMC6459891 DOI: 10.1038/s41598-019-42227-5] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Accepted: 03/27/2019] [Indexed: 12/21/2022] Open
Abstract
Horizontal gene transfer (HGT) is widespread in the evolution of prokaryotes, especially those associated with the human body. Here, we implemented large-scale gene-species phylogenetic tree reconstructions and reconciliations to identify putative HGT-derived genes in the reference genomes of microbiota isolated from six major human body sites by the NIH Human Microbiome Project. Comparisons with a control group representing microbial genomes from diverse natural environments indicated that HGT activity increased significantly in the genomes of human microbiota, which is confirmatory of previous findings. Roughly, more than half of total genes in the genomes of human-associated microbiota were transferred (donated or received) by HGT. Up to 60% of the detected HGTs occurred either prior to the colonization of the human body or involved bacteria residing in different body sites. The latter could suggest 'genetic crosstalk' and movement of bacterial genes within the human body via hitherto poorly understood mechanisms. We also observed that HGT activity increased significantly among closely-related microorganisms and especially when they were united by physical proximity, suggesting that the 'phylogenetic effect' can significantly boost HGT activity. Finally, we identified several core and widespread genes least influenced by HGT that could become useful markers for building robust 'trees of life' and address several outstanding technical challenges to improve the phylogeny-based genome-wide HGT detection method for future applications.
Collapse
Affiliation(s)
- Hyeonsoo Jeong
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA.,School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, United States
| | - Bushra Arif
- Department of Biosciences, COMSATS University Islamabad, Park Road, Tarlai Kalan, Islamabad, Pakistan
| | | | - Kyung Mo Kim
- Division of Polar Life Sciences, Korea Polar Research Institute, Incheon, Republic of Korea.
| | - Arshan Nasir
- Department of Biosciences, COMSATS University Islamabad, Park Road, Tarlai Kalan, Islamabad, Pakistan.
| |
Collapse
|
143
|
Abed M, Verschueren E, Budayeva H, Liu P, Kirkpatrick DS, Reja R, Kummerfeld SK, Webster JD, Gierke S, Reichelt M, Anderson KR, Newman RJ, Roose-Girma M, Modrusan Z, Pektas H, Maltepe E, Newton K, Dixit VM. The Gag protein PEG10 binds to RNA and regulates trophoblast stem cell lineage specification. PLoS One 2019; 14:e0214110. [PMID: 30951545 PMCID: PMC6450627 DOI: 10.1371/journal.pone.0214110] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Accepted: 03/15/2019] [Indexed: 01/03/2023] Open
Abstract
Peg10 (paternally expressed gene 10) is an imprinted gene that is essential for placental development. It is thought to derive from a Ty3-gyspy LTR (long terminal repeat) retrotransposon and retains Gag and Pol-like domains. Here we show that the Gag domain of PEG10 can promote vesicle budding similar to the HIV p24 Gag protein. Expressed in a subset of mouse endocrine organs in addition to the placenta, PEG10 was identified as a substrate of the deubiquitinating enzyme USP9X. Consistent with PEG10 having a critical role in placental development, PEG10-deficient trophoblast stem cells (TSCs) exhibited impaired differentiation into placental lineages. PEG10 expressed in wild-type, differentiating TSCs was bound to many cellular RNAs including Hbegf (Heparin-binding EGF-like growth factor), which is known to play an important role in placentation. Expression of Hbegf was reduced in PEG10-deficient TSCs suggesting that PEG10 might bind to and stabilize RNAs that are critical for normal placental development.
Collapse
Affiliation(s)
- Mona Abed
- Physiological Chemistry Department, Genentech, South San Francisco, California, United States of America
| | - Erik Verschueren
- Protein Chemistry Department, Genentech, South San Francisco, California, United States of America
| | - Hanna Budayeva
- Protein Chemistry Department, Genentech, South San Francisco, California, United States of America
| | - Peter Liu
- Protein Chemistry Department, Genentech, South San Francisco, California, United States of America
| | - Donald S. Kirkpatrick
- Protein Chemistry Department, Genentech, South San Francisco, California, United States of America
| | - Rohit Reja
- Bioinformatics and Computational Biology Department, Genentech, South San Francisco, California, United States of America
| | - Sarah K. Kummerfeld
- Bioinformatics and Computational Biology Department, Genentech, South San Francisco, California, United States of America
| | - Joshua D. Webster
- Pathology Department, Genentech, South San Francisco, California, United States of America
| | - Sarah Gierke
- Pathology Department, Genentech, South San Francisco, California, United States of America
| | - Mike Reichelt
- Pathology Department, Genentech, South San Francisco, California, United States of America
| | - Keith R. Anderson
- Molecular Biology Department, Genentech, South San Francisco, California, United States of America
| | - Robert J. Newman
- Molecular Biology Department, Genentech, South San Francisco, California, United States of America
| | - Merone Roose-Girma
- Molecular Biology Department, Genentech, South San Francisco, California, United States of America
| | - Zora Modrusan
- Molecular Biology Department, Genentech, South San Francisco, California, United States of America
| | - Hazal Pektas
- The Center for Reproductive Sciences, Division of Neonatology, University of California, San Francisco, California, United States of America
| | - Emin Maltepe
- The Center for Reproductive Sciences, Division of Neonatology, University of California, San Francisco, California, United States of America
| | - Kim Newton
- Physiological Chemistry Department, Genentech, South San Francisco, California, United States of America
| | - Vishva M. Dixit
- Physiological Chemistry Department, Genentech, South San Francisco, California, United States of America
- * E-mail:
| |
Collapse
|
144
|
Li C, Xiong W, Liu X, Xiao W, Guo Y, Tan J, Li Y. Hypomethylation at non-CpG/CpG sites in the promoter of HIF-1α gene combined with enhanced H3K9Ac modification contribute to maintain higher HIF-1α expression in breast cancer. Oncogenesis 2019; 8:26. [PMID: 30940798 PMCID: PMC6445832 DOI: 10.1038/s41389-019-0135-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 02/26/2019] [Accepted: 03/18/2019] [Indexed: 02/06/2023] Open
Abstract
HIF-1α has a broad impact on tumors, including enhanced utilization of glucose, tumor cell stemness, migration, metastasis and so on. In pilot study, we found that the expression of HIF-1α significantly increased in breast cancer cell lines and tissue samples with higher malignant behaviors and decreased in luminal subtype breast cancer cells and tissue samples. We analyzed and found there is one large CpG island in HIF-1α promoter around transcription start site, and the hypermethylation occurred at these CpGs and their surrounding non-CpGs sites. Epigenetic events driving tumorigenesis has been characterized. However, knowledge is lacking on the non-CpGs methylation of HIF-1α promoter in breast cancer cells. We validated that non-CpGs methylation can directly regulate HIF-1α expression by luciferase activity assay. We also found DNMT3a and Mecp2 play vital role in methylation at non-CpGs and CpGs sites. In addition, we noticed that H3K9ac modification could promote the transcription of HIF-1α in MDA-MB-231 cells by binding to the region contained hypomethylated non-CpG and CpG sites. Taken together, the hypomethylation status at non-CpG and CpG loci in HIF-1α promoter and H3K9ac modification together contribute to maintain higher HIF-1αactivity in invasive breast cancer cells when compared with the non-invasive breast cancer cells, which may establish a tissue-specific epigenetic modification pattern and point to the new directions for future understanding breast cancer therapy.
Collapse
Affiliation(s)
- Chun Li
- The central laboratory, of Cancer Hospital of Shantou University Medical College, No.7 Raoping Road, Shantou, 515031, China
- Department of Pathology, of Cancer Hospital of Shantou University Medical College, No.7 Raoping Road, Shantou, 515031, China
| | - Wei Xiong
- The central laboratory, of Cancer Hospital of Shantou University Medical College, No.7 Raoping Road, Shantou, 515031, China
| | - Xiong Liu
- The central laboratory, of Cancer Hospital of Shantou University Medical College, No.7 Raoping Road, Shantou, 515031, China
| | - Wenjun Xiao
- The central laboratory, of Cancer Hospital of Shantou University Medical College, No.7 Raoping Road, Shantou, 515031, China
| | - Yuxian Guo
- The central laboratory, of Cancer Hospital of Shantou University Medical College, No.7 Raoping Road, Shantou, 515031, China
| | - Junyu Tan
- The central laboratory, of Cancer Hospital of Shantou University Medical College, No.7 Raoping Road, Shantou, 515031, China
| | - Yaochen Li
- The central laboratory, of Cancer Hospital of Shantou University Medical College, No.7 Raoping Road, Shantou, 515031, China.
| |
Collapse
|
145
|
Centromere Repeats: Hidden Gems of the Genome. Genes (Basel) 2019; 10:genes10030223. [PMID: 30884847 PMCID: PMC6471113 DOI: 10.3390/genes10030223] [Citation(s) in RCA: 88] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 03/07/2019] [Accepted: 03/11/2019] [Indexed: 01/08/2023] Open
Abstract
Satellite DNAs are now regarded as powerful and active contributors to genomic and chromosomal evolution. Paired with mobile transposable elements, these repetitive sequences provide a dynamic mechanism through which novel karyotypic modifications and chromosomal rearrangements may occur. In this review, we discuss the regulatory activity of satellite DNA and their neighboring transposable elements in a chromosomal context with a particular emphasis on the integral role of both in centromere function. In addition, we discuss the varied mechanisms by which centromeric repeats have endured evolutionary processes, producing a novel, species-specific centromeric landscape despite sharing a ubiquitously conserved function. Finally, we highlight the role these repetitive elements play in the establishment and functionality of de novo centromeres and chromosomal breakpoints that underpin karyotypic variation. By emphasizing these unique activities of satellite DNAs and transposable elements, we hope to disparage the conventional exemplification of repetitive DNA in the historically-associated context of ‘junk’.
Collapse
|
146
|
Schumann GG, Fuchs NV, Tristán-Ramos P, Sebe A, Ivics Z, Heras SR. The impact of transposable element activity on therapeutically relevant human stem cells. Mob DNA 2019; 10:9. [PMID: 30899334 PMCID: PMC6408843 DOI: 10.1186/s13100-019-0151-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 02/27/2019] [Indexed: 12/11/2022] Open
Abstract
Human stem cells harbor significant potential for basic and clinical translational research as well as regenerative medicine. Currently ~ 3000 adult and ~ 30 pluripotent stem cell-based, interventional clinical trials are ongoing worldwide, and numbers are increasing continuously. Although stem cells are promising cell sources to treat a wide range of human diseases, there are also concerns regarding potential risks associated with their clinical use, including genomic instability and tumorigenesis concerns. Thus, a deeper understanding of the factors and molecular mechanisms contributing to stem cell genome stability are a prerequisite to harnessing their therapeutic potential for degenerative diseases. Chemical and physical factors are known to influence the stability of stem cell genomes, together with random mutations and Copy Number Variants (CNVs) that accumulated in cultured human stem cells. Here we review the activity of endogenous transposable elements (TEs) in human multipotent and pluripotent stem cells, and the consequences of their mobility for genomic integrity and host gene expression. We describe transcriptional and post-transcriptional mechanisms antagonizing the spread of TEs in the human genome, and highlight those that are more prevalent in multipotent and pluripotent stem cells. Notably, TEs do not only represent a source of mutations/CNVs in genomes, but are also often harnessed as tools to engineer the stem cell genome; thus, we also describe and discuss the most widely applied transposon-based tools and highlight the most relevant areas of their biomedical applications in stem cells. Taken together, this review will contribute to the assessment of the risk that endogenous TE activity and the application of genetically engineered TEs constitute for the biosafety of stem cells to be used for substitutive and regenerative cell therapies.
Collapse
Affiliation(s)
- Gerald G Schumann
- 1Division of Medical Biotechnology, Paul-Ehrlich-Institut, Paul-Ehrlich-Str.51-59, 63225 Langen, Germany
| | - Nina V Fuchs
- 2Host-Pathogen Interactions, Paul-Ehrlich-Institut, Paul-Ehrlich-Str. 51-59, 63225 Langen, Germany
| | - Pablo Tristán-Ramos
- 3GENYO. Centre for Genomics and Oncological Research, Pfizer/University of Granada/Andalusian Regional Government, PTS Granada-Avenida de la Ilustración, 114, 18016 Granada, Spain.,4Department of Biochemistry and Molecular Biology II, Faculty of Pharmacy, University of Granada, Campus Universitario de Cartuja, 18071 Granada, Spain
| | - Attila Sebe
- 1Division of Medical Biotechnology, Paul-Ehrlich-Institut, Paul-Ehrlich-Str.51-59, 63225 Langen, Germany
| | - Zoltán Ivics
- 1Division of Medical Biotechnology, Paul-Ehrlich-Institut, Paul-Ehrlich-Str.51-59, 63225 Langen, Germany
| | - Sara R Heras
- 3GENYO. Centre for Genomics and Oncological Research, Pfizer/University of Granada/Andalusian Regional Government, PTS Granada-Avenida de la Ilustración, 114, 18016 Granada, Spain.,4Department of Biochemistry and Molecular Biology II, Faculty of Pharmacy, University of Granada, Campus Universitario de Cartuja, 18071 Granada, Spain
| |
Collapse
|
147
|
Abstract
DNA methylation inhibitors have become the mainstay for treatment of certain haematological malignancies. In addition to their abilities to reactivate genes, including tumour suppressors, that have acquired DNA methylation during carcinogenesis, they induce the expression of thousands of transposable elements including endogenous retroviruses and latent cancer testis antigens normally silenced by DNA methylation in most somatic cells. This results in a state of viral mimicry in which treated cells mount an innate immune response by turning on viral defence genes and potentially expressing neoantigens. Furthermore, these changes mediated by DNA methylation inhibitors can also alter the function of immune cells relevant to acquired immunity. Additionally, other inhibitors of epigenetic processes, such as histone deacetylases, methylases and demethylases, can elicit similar effects either individually or in combinations with DNA methylation inhibitors. These findings together with rapid development of immunotherapies open new avenues for cancer treatment.
Collapse
Affiliation(s)
- Peter A Jones
- Van Andel Research Institute (VARI), Grand Rapids, MI, USA
| | - Hitoshi Ohtani
- Van Andel Research Institute (VARI), Grand Rapids, MI, USA
| | - Ankur Chakravarthy
- Princess Margaret Cancer Centre, University Health Network (UHN), Toronto, Ontario, Canada
| | - Daniel D De Carvalho
- Princess Margaret Cancer Centre, University Health Network (UHN), Toronto, Ontario, Canada.
- Department of Medical Biophysics, University of Toronto, Toronto, Canada.
| |
Collapse
|
148
|
Lewis L, Chappell GA, Kobets T, O'Brian BE, Sangaraju D, Kosyk O, Bodnar W, Tretyakova NY, Pogribny IP, Rusyn I. Sex-specific differences in genotoxic and epigenetic effects of 1,3-butadiene among mouse tissues. Arch Toxicol 2019; 93:791-800. [PMID: 30552462 PMCID: PMC6451682 DOI: 10.1007/s00204-018-2374-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2018] [Accepted: 12/10/2018] [Indexed: 01/31/2023]
Abstract
Exposure to environmental chemicals has been shown to have an impact on the epigenome. One example is a known human carcinogen 1,3-butadiene which acts primarily by a genotoxic mechanism, but also disrupts the chromatin structure by altering patterns of cytosine DNA methylation and histone modifications. Sex-specific differences in 1,3-butadiene-induced genotoxicity and carcinogenicity are well established; however, it remains unknown whether 1,3-butadiene-associated epigenetic alterations are also sex dependent. Therefore, we tested the hypothesis that inhalational exposure to 1,3-butadiene will result in sex-specific epigenetic alterations. DNA damage and epigenetic effects of 1,3-butadiene were evaluated in liver, lung, and kidney tissues of male and female mice of two inbred strains (C57BL/6J and CAST/EiJ). Mice were exposed to 0 or 425 ppm of 1,3-butadiene by inhalation (6 h/day, 5 days/week) for 2 weeks. Strain- and tissue-specific differences in 1,3-butadiene-induced DNA adducts and crosslinks were detected in the liver, lung and kidney; however, significant sex-specific differences in DNA damage were observed in the lung of C57BL/6J mice only. In addition, we assessed expression of the DNA repair genes and observed a marked upregulation of Mgmt in the kidney in female C57BL/6J mice. Sex-specific epigenetic effects of 1,3-butadiene exposure were evident in alterations of cytosine DNA methylation and histone modifications in the liver and lung in both strains. Specifically, we observed a loss of cytosine DNA methylation in the liver and lung of male and female 1,3-butadiene-exposed C57BL/6J mice, whereas hypermethylation was found in the liver and lung in 1,3-butadiene-exposed female CAST/EiJ mice. Our findings suggest that strain- and sex-specific effects of 1,3-butadiene on the epigenome may contribute to the known differences in cancer susceptibility.
Collapse
Affiliation(s)
- Lauren Lewis
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA
| | - Grace A Chappell
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA
| | - Tetyana Kobets
- Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, NC, USA
| | - Bridget E O'Brian
- Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, NC, USA
| | - Dewakar Sangaraju
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN, USA
| | - Oksana Kosyk
- Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, NC, USA
| | - Wanda Bodnar
- Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, NC, USA
| | - Natalia Y Tretyakova
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN, USA
| | - Igor P Pogribny
- Division of Biochemical Toxicology, National Center for Toxicological Research, Food and Drug Administration, Jefferson, AR, USA
| | - Ivan Rusyn
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA.
| |
Collapse
|
149
|
Huang W, Zhao C, Zhong H, Zhang S, Xia Y, Cai Z. Bisphenol S induced epigenetic and transcriptional changes in human breast cancer cell line MCF-7. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 246:697-703. [PMID: 30616060 DOI: 10.1016/j.envpol.2018.12.084] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 12/07/2018] [Accepted: 12/27/2018] [Indexed: 05/18/2023]
Abstract
In recent years, concerns about using Bisphenol A (BPA) in daily consume products and its effects in many chronic human diseases have prompted the removal of BPA. However, the widely used BPA alternatives, including Bisphenol S (BPS), have a high structural similarity with BPA, suggesting that they may have similar biological effects towards human beings. Indeed, BPS was also found to have endocrine-disrupting effects. Epigenetic mechanism was reported to be involved in BPA-induced biological effects in both in vitro and in vivo models. However, there is no assessment on whether BPS could cause epigenetic changes. In this work, we investigated the possible epigenetic effects of BPS that might induce in human breast cancer cell line MCF-7. We found that BPS could change DNA methylation level of transposons. Besides, methylation status in promoter of breast cancer related genes CDH1, SFN, TNFRSF10C were also changed, which implied that BPS might play a role in the development of breast cancer. Gene expression profiling showed that some genes related to breast cancer progression were upregulated, including THBS4, PPARGC1A, CREB5, COL5A3. Gene ontology (GO) analysis of the differentially expressed genes revealed the significantly changes in PI3K-Akt signaling pathway and extracellular matrix, which were related to the proliferation, migration and invasion of breast cancer cells. These results illustrated that BPS exposure might play roles in the progression of breast cancer.
Collapse
Affiliation(s)
- Wei Huang
- State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong SAR, PR China
| | - Chao Zhao
- State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong SAR, PR China
| | - Huan Zhong
- Department of Biology, Hong Kong Baptist University, Hong Kong SAR, PR China
| | - Shoudong Zhang
- Department of Biology, Hong Kong Baptist University, Hong Kong SAR, PR China
| | - Yiji Xia
- Department of Biology, Hong Kong Baptist University, Hong Kong SAR, PR China
| | - Zongwei Cai
- State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong SAR, PR China.
| |
Collapse
|
150
|
Wnt/β-catenin signaling pathway safeguards epigenetic stability and homeostasis of mouse embryonic stem cells. Sci Rep 2019; 9:948. [PMID: 30700782 PMCID: PMC6353868 DOI: 10.1038/s41598-018-37442-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Accepted: 12/03/2018] [Indexed: 12/22/2022] Open
Abstract
Mouse embryonic stem cells (mESCs) are pluripotent and can differentiate into cells belonging to the three germ layers of the embryo. However, mESC pluripotency and genome stability can be compromised in prolonged in vitro culture conditions. Several factors control mESC pluripotency, including Wnt/β-catenin signaling pathway, which is essential for mESC differentiation and proliferation. Here we show that the activity of the Wnt/β-catenin signaling pathway safeguards normal DNA methylation of mESCs. The activity of the pathway is progressively silenced during passages in culture and this results into a loss of the DNA methylation at many imprinting control regions (ICRs), loss of recruitment of chromatin repressors, and activation of retrotransposons, resulting into impaired mESC differentiation. Accordingly, sustained Wnt/β-catenin signaling maintains normal ICR methylation and mESC homeostasis and is a key regulator of genome stability.
Collapse
|