101
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Sakamoto Y, Zaha S, Nagasawa S, Miyake S, Kojima Y, Suzuki A, Suzuki Y, Seki M. Long-read whole-genome methylation patterning using enzymatic base conversion and nanopore sequencing. Nucleic Acids Res 2021; 49:e81. [PMID: 34019650 PMCID: PMC8373077 DOI: 10.1093/nar/gkab397] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 04/09/2021] [Accepted: 04/30/2021] [Indexed: 12/14/2022] Open
Abstract
Long-read whole-genome sequencing analysis of DNA methylation would provide useful information on the chromosomal context of gene expression regulation. Here we describe the development of a method that improves the read length generated by using the bisulfite-sequencing-based approach. In this method, we combined recently developed enzymatic base conversion, where an unmethylated cytosine (C) should be converted to thymine (T), with nanopore sequencing. After methylation-sensitive base conversion, the sequencing library was constructed using long-range polymerase chain reaction. This type of analysis is possible using a minimum of 1 ng genomic DNA, and an N50 read length of 3.4–7.6 kb is achieved. To analyze the produced data, which contained a substantial number of base mismatches due to sequence conversion and an inaccurate base read of the nanopore sequencing, a new analytical pipeline was constructed. To demonstrate the performance of long-read methylation sequencing, breast cancer cell lines and clinical specimens were subjected to analysis, which revealed the chromosomal methylation context of key cancer-related genes, allele-specific methylated genes, and repetitive or deletion regions. This method should convert the intractable specimens for which the amount of available genomic DNA is limited to the tractable targets.
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Affiliation(s)
- Yoshitaka Sakamoto
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, Japan
| | - Suzuko Zaha
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, Japan
| | - Satoi Nagasawa
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, Japan
| | - Shuhei Miyake
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, Japan
| | - Yasuyuki Kojima
- Division of Breast and Endocrine Surgery, Department of Surgery, St. Marianna University School of Medicine, Kawasaki, Kanagawa, Japan
| | - Ayako Suzuki
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, Japan
| | - Yutaka Suzuki
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, Japan
| | - Masahide Seki
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, Japan
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102
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Beck D, Ben Maamar M, Skinner MK. Genome-wide CpG density and DNA methylation analysis method (MeDIP, RRBS, and WGBS) comparisons. Epigenetics 2021; 17:518-530. [PMID: 33975521 PMCID: PMC9067529 DOI: 10.1080/15592294.2021.1924970] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
Genome-wide DNA methylation analysis is one of the most common epigenetic processes analysed for genome characterization and differential DNA methylation assessment. Previous genome-wide analysis has suggested an important variable in DNA methylation methods involves CpG density. The current study was designed to investigate the CpG density in a variety of different species genomes and correlate this to various DNA methylation analysis data sets. The majority of all genomes had >90% of the genome in the low density 1-3 CpG/100 bp category, while <10% of the genome was in the higher density >5 CpG/100 bp category. Similar observations with human, rat, bird, and fish genomes were observed. The methylated DNA immunoprecipitation (MeDIP) procedure uses the anti-5-methylcytosine antibody immunoprecipitation followed by next-generation sequencing (MeDIP-Seq). The MeDIP procedure is biased to lower CpG density of <5 CpG/100 bp, which corresponds to >95% of the genome. The reduced representation bisulphite (RRBS) protocol generally identifies DMRs in higher CpG density regions of ≥3 CpG/100 bp which corresponds to approximately 20% of the genome. The whole-genome bisulphite (WGBS) analyses resulted in higher CpG densities, often greater than 10 CpG/100bp. WGBS generally identifies ≥2 CpG/100bp, which corresponds to approximately 50% of the genome. Limitations and potential optimization approaches for each method are discussed. None of the procedures can provide complete genome-wide assessment of the genome, but MeDIP-Seq provides coverage of the highest percentage. Observations demonstrate that CpG density is a critical variable in DNA methylation analysis, and different molecular techniques focus on distinct genomic regions.
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Affiliation(s)
- Daniel Beck
- Center for Reproductive Biology, School of Biological Sciences, Washington State University, Pullman, WA, USA
| | - Millissia Ben Maamar
- Center for Reproductive Biology, School of Biological Sciences, Washington State University, Pullman, WA, USA
| | - Michael K Skinner
- Center for Reproductive Biology, School of Biological Sciences, Washington State University, Pullman, WA, USA
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103
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Villicaña S, Bell JT. Genetic impacts on DNA methylation: research findings and future perspectives. Genome Biol 2021; 22:127. [PMID: 33931130 PMCID: PMC8086086 DOI: 10.1186/s13059-021-02347-6] [Citation(s) in RCA: 83] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 04/09/2021] [Indexed: 12/17/2022] Open
Abstract
Multiple recent studies highlight that genetic variants can have strong impacts on a significant proportion of the human DNA methylome. Methylation quantitative trait loci, or meQTLs, allow for the exploration of biological mechanisms that underlie complex human phenotypes, with potential insights for human disease onset and progression. In this review, we summarize recent milestones in characterizing the human genetic basis of DNA methylation variation over the last decade, including heritability findings and genome-wide identification of meQTLs. We also discuss challenges in this field and future areas of research geared to generate insights into molecular processes underlying human complex traits.
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Affiliation(s)
- Sergio Villicaña
- Department of Twin Research and Genetic Epidemiology, St. Thomas’ Hospital, King’s College London, 3rd Floor, South Wing, Block D, London, SE1 7EH UK
| | - Jordana T. Bell
- Department of Twin Research and Genetic Epidemiology, St. Thomas’ Hospital, King’s College London, 3rd Floor, South Wing, Block D, London, SE1 7EH UK
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104
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Current Advances in DNA Methylation Analysis Methods. BIOMED RESEARCH INTERNATIONAL 2021; 2021:8827516. [PMID: 33824878 PMCID: PMC8007345 DOI: 10.1155/2021/8827516] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 02/04/2021] [Accepted: 03/01/2021] [Indexed: 12/18/2022]
Abstract
DNA methylation is one of the epigenetic changes, which plays a major role in regulating gene expression and, thus, many biological processes and diseases. There are several methods for determining the methylation of DNA samples. However, selecting the most appropriate method for answering biological questions appears to be a challenging task. The primary methods in DNA methylation focused on identifying the state of methylation of the examined genes and determining the total amount of 5-methyl cytosine. The study of DNA methylation at a large scale of genomic levels became possible following the use of microarray hybridization technology. The new generation of sequencing platforms now allows the preparation of genomic maps of DNA methylation at the single-open level. This review includes the majority of methods available to date, introducing the most widely used methods, the bisulfite treatment, biological identification, and chemical cutting along with their advantages and disadvantages. The techniques are then scrutinized according to their robustness, high throughput capabilities, and cost.
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105
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The Genetic Component of Seagrass Restoration: What We Know and the Way Forwards. WATER 2021. [DOI: 10.3390/w13060829] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Seagrasses are marine flowering plants providing key ecological services and functions in coasts and estuaries across the globe. Increased environmental changes fueled by human activities are affecting their existence, compromising natural habitats and ecosystems’ biodiversity and functioning. In this context, restoration of disturbed seagrass environments has become a worldwide priority to reverse ecosystem degradation and to recover ecosystem functionality and associated services. Despite the proven importance of genetic research to perform successful restoration projects, this aspect has often been overlooked in seagrass restoration. Here, we aimed to provide a comprehensive perspective of genetic aspects related to seagrass restoration. To this end, we first reviewed the importance of studying the genetic diversity and population structure of target seagrass populations; then, we discussed the pros and cons of different approaches used to restore and/or reinforce degraded populations. In general, the collection of genetic information and the development of connectivity maps are critical steps for any seagrass restoration activity. Traditionally, the selection of donor population preferred the use of local gene pools, thought to be the best adapted to current conditions. However, in the face of rapid ocean changes, alternative approaches such as the use of climate-adjusted or admixture genotypes might provide more sustainable options to secure the survival of restored meadows. Also, we discussed different transplantation strategies applied in seagrasses and emphasized the importance of long-term seagrass monitoring in restoration. The newly developed information on epigenetics as well as the application of assisted evolution strategies were also explored. Finally, a view of legal and ethical issues related to national and international restoration management is included, highlighting improvements and potential new directions to integrate with the genetic assessment. We concluded that a good restoration effort should incorporate: (1) a good understanding of the genetic structure of both donors and populations being restored; (2) the analysis of local environmental conditions and disturbances that affect the site to be restored; (3) the analysis of local adaptation constraints influencing the performances of donor populations and native plants; (4) the integration of distribution/connectivity maps with genetic information and environmental factors relative to the target seagrass populations; (5) the planning of long-term monitoring programs to assess the performance of the restored populations. The inclusion of epigenetic knowledge and the development of assisted evolution programs are strongly hoped for the future.
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106
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Ross SE, Hesselson D, Bogdanovic O. Developmental Accumulation of Gene Body and Transposon Non-CpG Methylation in the Zebrafish Brain. Front Cell Dev Biol 2021; 9:643603. [PMID: 33748137 PMCID: PMC7978034 DOI: 10.3389/fcell.2021.643603] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 02/08/2021] [Indexed: 12/13/2022] Open
Abstract
DNA methylation predominantly occurs at CG dinucleotides in vertebrate genomes; however, non-CG methylation (mCH) is also detectable in vertebrate tissues, most notably in the nervous system. In mammals it is well established that mCH is targeted to CAC trinucleotides by DNMT3A during nervous system development where it is enriched in gene bodies and associated with transcriptional repression. Nevertheless, the conservation of developmental mCH accumulation and its deposition by DNMT3A is largely unexplored and has yet to be functionally demonstrated in other vertebrates. In this study, by analyzing DNA methylomes and transcriptomes of zebrafish brains, we identified enrichment of mCH at CAC trinucleotides (mCAC) at defined transposon motifs as well as in developmentally downregulated genes associated with developmental and neural functions. We further generated and analyzed DNA methylomes and transcriptomes of developing zebrafish larvae and demonstrated that, like in mammals, mCH accumulates during post-embryonic brain development. Finally, by employing CRISPR/Cas9 technology, we unraveled a conserved role for Dnmt3a enzymes in developmental mCAC deposition. Overall, this work demonstrates the evolutionary conservation of developmental mCH dynamics and highlights the potential of zebrafish as a model to study mCH regulation and function during normal and perturbed development.
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Affiliation(s)
- Samuel E Ross
- Genomics and Epigenetics Division, Garvan Institute of Medical Research, Sydney, NSW, Australia.,Faculty of Medicine, St Vincent's Clinical School, University of New South Wales, Sydney, NSW, Australia
| | - Daniel Hesselson
- Centenary Institute, The University of Sydney, Sydney, NSW, Australia.,Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Ozren Bogdanovic
- Genomics and Epigenetics Division, Garvan Institute of Medical Research, Sydney, NSW, Australia.,School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
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107
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Arora I, Tollefsbol TO. Computational methods and next-generation sequencing approaches to analyze epigenetics data: Profiling of methods and applications. Methods 2021; 187:92-103. [PMID: 32941995 PMCID: PMC7914156 DOI: 10.1016/j.ymeth.2020.09.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 09/08/2020] [Accepted: 09/10/2020] [Indexed: 12/20/2022] Open
Abstract
Epigenetics is mainly comprised of features that regulate genomic interactions thereby playing a crucial role in a vast array of biological processes. Epigenetic mechanisms such as DNA methylation and histone modifications influence gene expression by modulating the packaging of DNA in the nucleus. A plethora of studies have emphasized the importance of analyzing epigenetics data through genome-wide studies and high-throughput approaches, thereby providing key insights towards epigenetics-based diseases such as cancer. Recent advancements have been made towards translating epigenetics research into a high throughput approach such as genome-scale profiling. Amongst all, bioinformatics plays a pivotal role in achieving epigenetics-related computational studies. Despite significant advancements towards epigenomic profiling, it is challenging to understand how various epigenetic modifications such as chromatin modifications and DNA methylation regulate gene expression. Next-generation sequencing (NGS) provides accurate and parallel sequencing thereby allowing researchers to comprehend epigenomic profiling. In this review, we summarize different computational methods such as machine learning and other bioinformatics tools, publicly available databases and resources to identify key modifications associated with epigenetic machinery. Additionally, the review also focuses on understanding recent methodologies related to epigenome profiling using NGS methods ranging from library preparation, different sequencing platforms and analytical techniques to evaluate various epigenetic modifications such as DNA methylation and histone modifications. We also provide detailed information on bioinformatics tools and computational strategies responsible for analyzing large scale data in epigenetics.
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Affiliation(s)
- Itika Arora
- Department of Biology, University of Alabama at Birmingham, 1300 University Boulevard, Birmingham, AL 35294, USA.
| | - Trygve O Tollefsbol
- Department of Biology, University of Alabama at Birmingham, 1300 University Boulevard, Birmingham, AL 35294, USA; Comprehensive Center for Healthy Aging, University of Alabama Birmingham, 1530 3rd Avenue South, Birmingham, AL 35294, USA; Comprehensive Cancer Center, University of Alabama Birmingham, 1802 6th Avenue South, Birmingham, AL 35294, USA; Nutrition Obesity Research Center, University of Alabama Birmingham, 1675 University Boulevard, Birmingham, AL 35294, USA; Comprehensive Diabetes Center, University of Alabama Birmingham, 1825 University Boulevard, Birmingham, AL 35294, USA.
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108
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Nunn A, Otto C, Stadler PF, Langenberger D. Comprehensive benchmarking of software for mapping whole genome bisulfite data: from read alignment to DNA methylation analysis. Brief Bioinform 2021; 22:6146770. [PMID: 33624017 PMCID: PMC8425420 DOI: 10.1093/bib/bbab021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 12/30/2020] [Indexed: 01/23/2023] Open
Abstract
Whole genome bisulfite sequencing is currently at the forefront of epigenetic analysis, facilitating the nucleotide-level resolution of 5-methylcytosine (5mC) on a genome-wide scale. Specialized software have been developed to accommodate the unique difficulties in aligning such sequencing reads to a given reference, building on the knowledge acquired from model organisms such as human, or Arabidopsis thaliana. As the field of epigenetics expands its purview to non-model plant species, new challenges arise which bring into question the suitability of previously established tools. Herein, nine short-read aligners are evaluated: Bismark, BS-Seeker2, BSMAP, BWA-meth, ERNE-BS5, GEM3, GSNAP, Last and segemehl. Precision-recall of simulated alignments, in comparison to real sequencing data obtained from three natural accessions, reveals on-balance that BWA-meth and BSMAP are able to make the best use of the data during mapping. The influence of difficult-to-map regions, characterized by deviations in sequencing depth over repeat annotations, is evaluated in terms of the mean absolute deviation of the resulting methylation calls in comparison to a realistic methylome. Downstream methylation analysis is responsive to the handling of multi-mapping reads relative to mapping quality (MAPQ), and potentially susceptible to bias arising from the increased sequence complexity of densely methylated reads.
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Affiliation(s)
- Adam Nunn
- ecSeq Bioinformatics GmbH, Sternwartenstraße 29, 04103, Saxony, Germany.,Institut für Informatik, Universität Leipzig, Härtelstraße 16-18, 04107, Saxony, Germany
| | - Christian Otto
- ecSeq Bioinformatics GmbH, Sternwartenstraße 29, 04103, Saxony, Germany
| | - Peter F Stadler
- Institut für Informatik, Universität Leipzig, Härtelstraße 16-18, 04107, Saxony, Germany
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109
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Whalley C, Payne K, Domingo E, Blake A, Richman S, Brooks J, Batis N, Spruce R, Mehanna H, Nankivell P, Beggs AD. Ultra-Low DNA Input into Whole Genome Methylation Assays and Detection of Oncogenic Methylation and Copy Number Variants in Circulating Tumour DNA. EPIGENOMES 2021; 5:6. [PMID: 33777442 PMCID: PMC7610445 DOI: 10.3390/epigenomes5010006] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 02/06/2021] [Accepted: 02/12/2021] [Indexed: 11/28/2022] Open
Abstract
Abnormal CpG methylation in cancer is ubiquitous and generally detected in tumour specimens using a variety of techniques at a resolution encompassing single CpG loci to genome wide coverage. Analysis of samples with very low DNA inputs, such as formalin fixed (FFPE) biopsy specimens from clinical trials or circulating tumour DNA is challenging at the genome-wide level because of lack of available input. We present the results of low input experiments into the Illumina Infinium HD methylation assay on FFPE specimens and ctDNA samples. METHODS For all experiments, the Infinium HD assay for methylation was used. In total, forty-eight FFPE specimens were used at varying concentrations (lowest input 50 ng); eighteen blood derived specimens (lowest input 10 ng) and six matched ctDNA input (lowest input 10 ng)/fresh tumour specimens (lowest input 250 ng) were processed. Downstream analysis was performed in R/Bioconductor for quality control metrics and differential methylation analysis as well as copy number calls. RESULTS Correlation coefficients for CpG methylation were high at the probe level averaged R2 = 0.99 for blood derived samples and R2 > 0.96 for the FFPE samples. When matched ctDNA/fresh tumour samples were compared, R2 > 0.91 between the two. Results of differential methylation analysis did not vary significantly by DNA input in either the blood or FFPE groups. There were differences seen in the ctDNA group as compared to their paired tumour sample, possibly because of enrichment for tumour material without contaminating normal. Copy number variants observed in the tumour were generally also seen in the paired ctDNA sample with good concordance via DQ plot. CONCLUSIONS The Illumina Infinium HD methylation assay can robustly detect methylation across a range of sample types, including ctDNA, down to an input of 10 ng. It can also reliably detect oncogenic methylation changes and copy number variants in ctDNA. These findings demonstrate that these samples can now be accessed by methylation array technology, allowing analysis of these important sample types.
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Affiliation(s)
- Celina Whalley
- Institute of Cancer & Genomic Sciences, University of Birmingham, Vincent Drive, Birmingham B15 2TT, UK; (C.W.); (K.P.); (J.B.); (N.B.); (R.S.); (H.M.); (P.N.)
| | - Karl Payne
- Institute of Cancer & Genomic Sciences, University of Birmingham, Vincent Drive, Birmingham B15 2TT, UK; (C.W.); (K.P.); (J.B.); (N.B.); (R.S.); (H.M.); (P.N.)
| | - Enric Domingo
- Department of Oncology, Nuffield Department of Medicine, University of Oxford, Oxford OX3 7BN, UK; (E.D.); (A.B.)
| | - Andrew Blake
- Department of Oncology, Nuffield Department of Medicine, University of Oxford, Oxford OX3 7BN, UK; (E.D.); (A.B.)
| | - Susan Richman
- Pathology and Data Analytics, Leeds Institute of Medical Research, St James University Hospital, Leeds LS2 9JT, UK;
| | - Jill Brooks
- Institute of Cancer & Genomic Sciences, University of Birmingham, Vincent Drive, Birmingham B15 2TT, UK; (C.W.); (K.P.); (J.B.); (N.B.); (R.S.); (H.M.); (P.N.)
| | - Nikolaos Batis
- Institute of Cancer & Genomic Sciences, University of Birmingham, Vincent Drive, Birmingham B15 2TT, UK; (C.W.); (K.P.); (J.B.); (N.B.); (R.S.); (H.M.); (P.N.)
| | - Rachel Spruce
- Institute of Cancer & Genomic Sciences, University of Birmingham, Vincent Drive, Birmingham B15 2TT, UK; (C.W.); (K.P.); (J.B.); (N.B.); (R.S.); (H.M.); (P.N.)
| | | | - Hisham Mehanna
- Institute of Cancer & Genomic Sciences, University of Birmingham, Vincent Drive, Birmingham B15 2TT, UK; (C.W.); (K.P.); (J.B.); (N.B.); (R.S.); (H.M.); (P.N.)
| | - Paul Nankivell
- Institute of Cancer & Genomic Sciences, University of Birmingham, Vincent Drive, Birmingham B15 2TT, UK; (C.W.); (K.P.); (J.B.); (N.B.); (R.S.); (H.M.); (P.N.)
| | - Andrew D. Beggs
- Institute of Cancer & Genomic Sciences, University of Birmingham, Vincent Drive, Birmingham B15 2TT, UK; (C.W.); (K.P.); (J.B.); (N.B.); (R.S.); (H.M.); (P.N.)
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110
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Li CC, Dong YH, Zou X, Luo X, Shen D, Hu J, Zhang CY. Label-Free and Template-Free Chemiluminescent Biosensor for Sensitive Detection of 5-Hydroxymethylcytosine in Genomic DNA. Anal Chem 2021; 93:1939-1943. [PMID: 33427439 DOI: 10.1021/acs.analchem.0c05419] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
5-Hydroxymethylcytosine (5hmC) is a modified base present at low levels in various mammalian cells, and it plays essential roles in gene expression, DNA demethylation, and genomic reprogramming. Herein, we develop a label-free and template-free chemiluminescent biosensor for sensitive detection of 5hmC in genomic DNAs based on 5hmC-specific glucosylation, periodate (IO4+) oxidation, biotinylation, and terminal deoxynucleotidyl transferase (TdT)-assisted isothermal amplification strategy, which we term hmC-GLIB-IAS. This hmC-GLIB-IAS exhibits distinct advantages of bisulfite-free, improved sensitivity, and genome-wide analysis of 5hmC at constant reaction temperature without the involvement of either specially labeled nucleic acid probes or specific templates for signal amplification. This method can sensitively detect 5hmC with a detection limit of 2.07 × 10-13 M, and it can detect 5hmC in the whole genome DNA with a detection limit of 3.92 × 10-5 ng/μL. Moreover, this method can distinguish 5hmC from 5-methylcytosine (5mC) and cytosine (C) and even discriminate 0.1% 5hmC in the mixture of 5hmC-DNA and 5mC-DNA. Importantly, this hmC-GLIB-IAS strategy enables genome-wide analysis without the involvement of either isotope-labeled substrates or specific antibodies, providing a powerful platform to detect 5hmC in real genomic DNA with high reproducibility and accuracy.
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Affiliation(s)
- Chen-Chen Li
- College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Shandong Provincial Key Laboratory of Clean Production of Fine Chemicals, Shandong Normal University, Jinan, Shandong 250014, China.,Key Laboratory of Optic-electric Sensing and Analytical Chemistry for Life Science, MOE; Shandong Key Laboratory of Biochemical Analysis; Key Laboratory of Analytical Chemistry for Life Science in Universities of Shandong; College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao, Shandong 266042, P. R. China
| | - Yue-Hong Dong
- College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Shandong Provincial Key Laboratory of Clean Production of Fine Chemicals, Shandong Normal University, Jinan, Shandong 250014, China
| | - Xiaoran Zou
- College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Shandong Provincial Key Laboratory of Clean Production of Fine Chemicals, Shandong Normal University, Jinan, Shandong 250014, China
| | - Xiliang Luo
- Key Laboratory of Optic-electric Sensing and Analytical Chemistry for Life Science, MOE; Shandong Key Laboratory of Biochemical Analysis; Key Laboratory of Analytical Chemistry for Life Science in Universities of Shandong; College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao, Shandong 266042, P. R. China
| | - Dazhong Shen
- College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Shandong Provincial Key Laboratory of Clean Production of Fine Chemicals, Shandong Normal University, Jinan, Shandong 250014, China
| | - Juan Hu
- College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Shandong Provincial Key Laboratory of Clean Production of Fine Chemicals, Shandong Normal University, Jinan, Shandong 250014, China
| | - Chun-Yang Zhang
- College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Shandong Provincial Key Laboratory of Clean Production of Fine Chemicals, Shandong Normal University, Jinan, Shandong 250014, China
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111
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Hearn J, Plenderleith F, Little TJ. DNA methylation differs extensively between strains of the same geographical origin and changes with age in Daphnia magna. Epigenetics Chromatin 2021; 14:4. [PMID: 33407738 PMCID: PMC7789248 DOI: 10.1186/s13072-020-00379-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 12/12/2020] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Patterns of methylation influence lifespan, but methylation and lifespan may also depend on diet, or differ between genotypes. Prior to this study, interactions between diet and genotype have not been explored together to determine their influence on methylation. The invertebrate Daphnia magna is an excellent choice for testing the epigenetic response to the environment: parthenogenetic offspring are identical to their siblings (making for powerful genetic comparisons), they are relatively short lived and have well-characterised inter-strain life-history trait differences. We performed a survival analysis in response to caloric restriction and then undertook a 47-replicate experiment testing the DNA methylation response to ageing and caloric restriction of two strains of D. magna. RESULTS Methylated cytosines (CpGs) were most prevalent in exons two to five of gene bodies. One strain exhibited a significantly increased lifespan in response to caloric restriction, but there was no effect of food-level CpG methylation status. Inter-strain differences dominated the methylation experiment with over 15,000 differently methylated CpGs. One gene, Me31b, was hypermethylated extensively in one strain and is a key regulator of embryonic expression. Sixty-one CpGs were differentially methylated between young and old individuals, including multiple CpGs within the histone H3 gene, which were hypermethylated in old individuals. Across all age-related CpGs, we identified a set that are highly correlated with chronological age. CONCLUSIONS Methylated cytosines are concentrated in early exons of gene sequences indicative of a directed, non-random, process despite the low overall DNA methylation percentage in this species. We identify no effect of caloric restriction on DNA methylation, contrary to our previous results, and established impacts of caloric restriction on phenotype and gene expression. We propose our approach here is more robust in invertebrates given genome-wide CpG distributions. For both strain and ageing, a single gene emerges as differentially methylated that for each factor could have widespread phenotypic effects. Our data showed the potential for an epigenetic clock at a subset of age positions, which is exciting but requires confirmation.
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Affiliation(s)
- Jack Hearn
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Fiona Plenderleith
- The James Hutton Institute, Craigiebuckler, Aberdeen, UK
- School of Biological Sciences, University of Aberdeen, Aberdeen, UK
| | - Tom J. Little
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
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112
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Abstract
A complete understanding of the dynamics and function of cytosine modifications in mammalian biology is lacking. Central to achieving this understanding is the availability of techniques that permit sensitive and specific genome-wide mapping of DNA modifications in mammalian DNA. The last decade has seen the development of a vast arsenal of novel profiling approaches enabling epigeneticists to tackle research questions that were previously out of reach. Here, we review the techniques currently available for profiling DNA modifications in mammals, discuss their strengths and weaknesses, and speculate on the future direction of DNA modification profiling technologies.
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Affiliation(s)
- Antonio Lentini
- Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden
| | - Colm E Nestor
- Department of Biomedical and Clinical Sciences (BKV), Crown Princess Victoria Children's Hospital, Linköping University, Linköping, Sweden.
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113
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Drag MH, Kilpeläinen TO. Cell-free DNA and RNA-measurement and applications in clinical diagnostics with focus on metabolic disorders. Physiol Genomics 2020; 53:33-46. [PMID: 33346689 DOI: 10.1152/physiolgenomics.00086.2020] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Circulating cell-free DNA (cfDNA) and RNA (cfRNA) hold enormous potential as a new class of biomarkers for the development of noninvasive liquid biopsies in many diseases and conditions. In recent years, cfDNA and cfRNA have been studied intensely as tools for noninvasive prenatal testing, solid organ transplantation, cancer screening, and monitoring of tumors. In obesity, higher cfDNA concentration indicates accelerated cellular turnover of adipocytes during expansion of adipose mass and may be directly involved in the development of adipose tissue insulin resistance by inducing inflammation. Furthermore, cfDNA and cfRNA have promising diagnostic value in a range of obesity-related metabolic disorders, such as nonalcoholic fatty liver disease, type 2 diabetes, and diabetic complications. Here, we review the current and future applications of cfDNA and cfRNA within clinical diagnostics, discuss technical and analytical challenges in the field, and summarize the opportunities of using cfDNA and cfRNA in the diagnostics and prognostics of obesity-related metabolic disorders.
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Affiliation(s)
- Markus H Drag
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Tuomas O Kilpeläinen
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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114
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Ross SE, Angeloni A, Geng FS, de Mendoza A, Bogdanovic O. Developmental remodelling of non-CG methylation at satellite DNA repeats. Nucleic Acids Res 2020; 48:12675-12688. [PMID: 33271598 PMCID: PMC7736785 DOI: 10.1093/nar/gkaa1135] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 11/03/2020] [Accepted: 11/06/2020] [Indexed: 12/15/2022] Open
Abstract
In vertebrates, DNA methylation predominantly occurs at CG dinucleotides however, widespread non-CG methylation (mCH) has been reported in mammalian embryonic stem cells and in the brain. In mammals, mCH is found at CAC trinucleotides in the nervous system, where it is associated with transcriptional repression, and at CAG trinucleotides in embryonic stem cells, where it positively correlates with transcription. Moreover, CAC methylation appears to be a conserved feature of adult vertebrate brains. Unlike any of those methylation signatures, here we describe a novel form of mCH that occurs in the TGCT context within zebrafish mosaic satellite repeats. TGCT methylation is inherited from both male and female gametes, remodelled during mid-blastula transition, and re-established during gastrulation in all embryonic layers. Moreover, we identify DNA methyltransferase 3ba (Dnmt3ba) as the primary enzyme responsible for the deposition of this mCH mark. Finally, we observe that TGCT-methylated repeats are specifically associated with H3K9me3-marked heterochromatin suggestive of a functional interplay between these two gene-regulatory marks. Altogether, this work provides insight into a novel form of vertebrate mCH and highlights the substrate diversity of vertebrate DNA methyltransferases.
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Affiliation(s)
- Samuel E Ross
- Genomics and Epigenetics Division, Garvan Institute of Medical Research, Sydney, New South Wales 2010, Australia
- St Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, New South Wales 2010, Australia
| | - Allegra Angeloni
- Genomics and Epigenetics Division, Garvan Institute of Medical Research, Sydney, New South Wales 2010, Australia
- St Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, New South Wales 2010, Australia
| | - Fan-Suo Geng
- Genomics and Epigenetics Division, Garvan Institute of Medical Research, Sydney, New South Wales 2010, Australia
- St Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, New South Wales 2010, Australia
| | - Alex de Mendoza
- School of Biological and Chemical Sciences, Queen Mary University of London, London, E1 4NS, UK
| | - Ozren Bogdanovic
- Genomics and Epigenetics Division, Garvan Institute of Medical Research, Sydney, New South Wales 2010, Australia
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia
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115
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Yin Y, Li J, Li J, Lee M, Zhao S, Guo L, Li J, Zhang M, Huang Y, Li XN, Deng Z, Sun D. LiBis: an ultrasensitive alignment augmentation for low-input bisulfite sequencing. Brief Bioinform 2020; 22:6034045. [PMID: 33316060 DOI: 10.1093/bib/bbaa332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 10/18/2020] [Accepted: 10/25/2020] [Indexed: 11/14/2022] Open
Abstract
The cell-free DNA (cfDNA) methylation profile in liquid biopsy has been utilized to diagnose early-stage disease and estimate therapy response. However, typical clinical procedures are capable of purifying only very small amounts of cfDNA. Whole-genome bisulfite sequencing (WGBS) is the gold standard for measuring DNA methylation; however, WGBS using small amounts of fragmented DNA introduces a critical challenge for data analysis, namely a low-mapping ratio. The resulting low sequencing depth and low coverage of CpG sites genome-wide is a bottleneck for the clinical application of cfDNA-based WGBS assays. We developed LiBis (Low-input Bisulfite Sequencing), a novel method for low-input WGBS data alignment. By dynamically clipping initially unmapped reads and remapping clipped fragments, we judiciously rescued those reads and uniquely aligned them to the genome. By substantially increasing the mapping ratio by up to 88%, LiBis dramatically improved the number of informative CpGs and the precision in quantifying the methylation status of individual CpG sites. LiBis significantly improved the cost efficiency of low-input WGBS experiments by dynamically removing contamination introduced by random priming. The high sensitivity and cost effectiveness afforded by LiBis for low-input samples will allow the discovery of genetic and epigenetic features suitable for downstream analysis and biomarker identification using liquid biopsy.
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Affiliation(s)
- Yue Yin
- Texas A&M University College of Medicine
| | - Jia Li
- Texas A&M University College of Medicine
| | - Jin Li
- Texas A&M University College of Medicine
| | | | | | | | | | | | - Yun Huang
- Texas A&M University College of Medicine
| | - Xiao-Nan Li
- Northwestern University Feinberg School of Medicine
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116
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Galardi F, De Luca F, Romagnoli D, Biagioni C, Moretti E, Biganzoli L, Di Leo A, Migliaccio I, Malorni L, Benelli M. Cell-Free DNA-Methylation-Based Methods and Applications in Oncology. Biomolecules 2020; 10:E1677. [PMID: 33334040 PMCID: PMC7765488 DOI: 10.3390/biom10121677] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 12/07/2020] [Accepted: 12/14/2020] [Indexed: 12/11/2022] Open
Abstract
Liquid biopsy based on cell-free DNA (cfDNA) enables non-invasive dynamic assessment of disease status in patients with cancer, both in the early and advanced settings. The analysis of DNA-methylation (DNAm) from cfDNA samples holds great promise due to the intrinsic characteristics of DNAm being more prevalent, pervasive, and cell- and tumor-type specific than genomics, for which established cfDNA assays already exist. Herein, we report on recent advances on experimental strategies for the analysis of DNAm in cfDNA samples. We describe the main steps of DNAm-based analysis workflows, including pre-analytics of cfDNA samples, DNA treatment, assays for DNAm evaluation, and methods for data analysis. We report on protocols, biomolecular techniques, and computational strategies enabling DNAm evaluation in the context of cfDNA analysis, along with practical considerations on input sample requirements and costs. We provide an overview on existing studies exploiting cell-free DNAm biomarkers for the detection and monitoring of cancer in early and advanced settings, for the evaluation of drug resistance, and for the identification of the cell-of-origin of tumors. Finally, we report on DNAm-based tests approved for clinical use and summarize their performance in the context of liquid biopsy.
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Affiliation(s)
- Francesca Galardi
- «Sandro Pitigliani» Translational Research Unit, Hospital of Prato, 59100 Prato, Italy; (F.G.); (F.D.L.); (I.M.); (L.M.)
| | - Francesca De Luca
- «Sandro Pitigliani» Translational Research Unit, Hospital of Prato, 59100 Prato, Italy; (F.G.); (F.D.L.); (I.M.); (L.M.)
| | - Dario Romagnoli
- Bioinformatics Unit, Hospital of Prato, 59100 Prato, Italy; (D.R.); (C.B.)
| | - Chiara Biagioni
- Bioinformatics Unit, Hospital of Prato, 59100 Prato, Italy; (D.R.); (C.B.)
- «Sandro Pitigliani» Medical Oncology Department, Hospital of Prato, 59100 Prato, Italy; (E.M.); (L.B.); (A.D.L.)
| | - Erica Moretti
- «Sandro Pitigliani» Medical Oncology Department, Hospital of Prato, 59100 Prato, Italy; (E.M.); (L.B.); (A.D.L.)
| | - Laura Biganzoli
- «Sandro Pitigliani» Medical Oncology Department, Hospital of Prato, 59100 Prato, Italy; (E.M.); (L.B.); (A.D.L.)
| | - Angelo Di Leo
- «Sandro Pitigliani» Medical Oncology Department, Hospital of Prato, 59100 Prato, Italy; (E.M.); (L.B.); (A.D.L.)
| | - Ilenia Migliaccio
- «Sandro Pitigliani» Translational Research Unit, Hospital of Prato, 59100 Prato, Italy; (F.G.); (F.D.L.); (I.M.); (L.M.)
| | - Luca Malorni
- «Sandro Pitigliani» Translational Research Unit, Hospital of Prato, 59100 Prato, Italy; (F.G.); (F.D.L.); (I.M.); (L.M.)
- «Sandro Pitigliani» Medical Oncology Department, Hospital of Prato, 59100 Prato, Italy; (E.M.); (L.B.); (A.D.L.)
| | - Matteo Benelli
- Bioinformatics Unit, Hospital of Prato, 59100 Prato, Italy; (D.R.); (C.B.)
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117
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Genome-wide DNA methylation analysis of breast cancer MCF-7 / Taxol cells with MeDIP-Seq. PLoS One 2020; 15:e0241515. [PMID: 33306680 PMCID: PMC7732127 DOI: 10.1371/journal.pone.0241515] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Accepted: 09/16/2020] [Indexed: 11/19/2022] Open
Abstract
Breast cancer (BC) is the most frequently diagnosed tumor in women worldwide. Although the combination of surgery and Taxol chemotherapy can achieve a certain therapeutic effect, patients often develop drug-resistance, resulting in a poor prognosis. Therefore, it is significative to seek the molecular mechanism of chemotherapy resistance. Recent studies have found that abnormal epigenetic regulation in breast cells changes the expression of key genes, which can lead to the occurrence, development, and maintenance of cancer, even related to the development of drug-resistance. Therefore, in this study, we performed methylated DNA immunoprecipitation-sequencing (MeDIP-seq) to reveal the difference in methylation between breast cancer drug-resistant cells and sensitive cells. A total of 55076 differentially methylated genes (DMGs) were detected, including 21061 hypermethylated DMGs and 34015 hypomethylated DMGs. Moreover, Gene Ontology (GO) analysis and KEGG pathway analysis reveal the function and pathway of screening genes. These results indicate that DNA methylation may be involved in regulating the occurrence and development of breast cancer.
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118
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Lee I, Razaghi R, Gilpatrick T, Molnar M, Gershman A, Sadowski N, Sedlazeck FJ, Hansen KD, Simpson JT, Timp W. Simultaneous profiling of chromatin accessibility and methylation on human cell lines with nanopore sequencing. Nat Methods 2020; 17:1191-1199. [PMID: 33230324 PMCID: PMC7704922 DOI: 10.1038/s41592-020-01000-7] [Citation(s) in RCA: 93] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 10/17/2020] [Indexed: 12/30/2022]
Abstract
Probing epigenetic features on DNA has tremendous potential to advance our understanding of the phased epigenome. In this study, we use nanopore sequencing to evaluate CpG methylation and chromatin accessibility simultaneously on long strands of DNA by applying GpC methyltransferase to exogenously label open chromatin. We performed nanopore sequencing of nucleosome occupancy and methylome (nanoNOMe) on four human cell lines (GM12878, MCF-10A, MCF-7 and MDA-MB-231). The single-molecule resolution allows footprinting of protein and nucleosome binding, and determination of the combinatorial promoter epigenetic signature on individual molecules. Long-read sequencing makes it possible to robustly assign reads to haplotypes, allowing us to generate a fully phased human epigenome, consisting of chromosome-level allele-specific profiles of CpG methylation and chromatin accessibility. We further apply this to a breast cancer model to evaluate differential methylation and accessibility between cancerous and noncancerous cells.
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Affiliation(s)
- Isac Lee
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Roham Razaghi
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Timothy Gilpatrick
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Michael Molnar
- Ontario Institute for Cancer Research, Toronto, Ontario, Canada
| | - Ariel Gershman
- Department of Molecular Biology and Genetics, Johns Hopkins University, Baltimore, MD, USA
| | - Norah Sadowski
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Fritz J Sedlazeck
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, USA
| | - Kasper D Hansen
- Department of Biostatistics, Johns Hopkins School of Public Health, Baltimore, MD, USA
| | - Jared T Simpson
- Ontario Institute for Cancer Research, Toronto, Ontario, Canada
- Department of Computer Science, University of Toronto, Toronto, Ontario, Canada
| | - Winston Timp
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA.
- Department of Molecular Biology and Genetics, Johns Hopkins University, Baltimore, MD, USA.
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119
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Saha D, Norvil AB, Lanman NA, Gowher H. Simplified MethylRAD Sequencing to Detect Changes in DNA Methylation at Enhancer Elements in Differentiating Embryonic Stem Cells. EPIGENOMES 2020; 4:24. [PMID: 33828860 PMCID: PMC8023688 DOI: 10.3390/epigenomes4040024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Accepted: 09/28/2020] [Indexed: 11/17/2022] Open
Abstract
Differential DNA methylation is characteristic of gene regulatory regions, such as enhancers, which mostly constitute low or intermediate CpG content in their DNA sequence. Consequently, quantification of changes in DNA methylation at these sites is challenging. Given that DNA methylation across most of the mammalian genome is maintained, the use of genome-wide bisulfite sequencing to measure fractional changes in DNA methylation at specific sites is an overexertion which is both expensive and cumbersome. Here, we developed a MethylRAD technique with an improved experimental plan and bioinformatic analysis tool to examine regional DNA methylation changes in embryonic stem cells (ESCs) during differentiation. The transcriptional silencing of pluripotency genes (PpGs) during ESC differentiation is accompanied by PpG enhancer (PpGe) silencing mediated by the demethylation of H3K4me1 by LSD1. Our MethylRAD data show that in the presence of LSD1 inhibitor, a significant fraction of LSD1-bound PpGe fails to gain DNA methylation. We further show that this effect is mostly observed in PpGes with low/intermediate CpG content. Underscoring the sensitivity and accuracy of MethylRAD sequencing, our study demonstrates that this method can detect small changes in DNA methylation in regulatory regions, including those with low/intermediate CpG content, thus asserting its use as a method of choice for diagnostic purposes.
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Affiliation(s)
- Debapriya Saha
- Department of Biochemistry, Purdue University, West Lafayette, IN 47907, USA; (D.S.); (A.B.N.)
| | - Allison B. Norvil
- Department of Biochemistry, Purdue University, West Lafayette, IN 47907, USA; (D.S.); (A.B.N.)
| | - Nadia A. Lanman
- Purdue University Center for Cancer Research, Purdue University, West Lafayette, IN 47907, USA;
- Department of Comparative Pathobiology, Purdue University, West Lafayette, IN 47907, USA
| | - Humaira Gowher
- Department of Biochemistry, Purdue University, West Lafayette, IN 47907, USA; (D.S.); (A.B.N.)
- Purdue University Center for Cancer Research, Purdue University, West Lafayette, IN 47907, USA;
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120
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Molecular Plasticity in Animal Pigmentation: Emerging Processes Underlying Color Changes. Integr Comp Biol 2020; 60:1531-1543. [DOI: 10.1093/icb/icaa142] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Synopsis
Animal coloration has been rigorously studied and has provided morphological implications for fitness with influences over social behavior, predator–prey interactions, and sexual selection. In vertebrates, its study has developed our understanding across diverse fields ranging from behavior to molecular biology. In the search for underlying molecular mechanisms, many have taken advantage of pedigree-based and genome-wide association screens to reveal the genetic architecture responsible for pattern variation that occurs in early development. However, genetic differences do not provide a full picture of the dynamic changes in coloration that are most prevalent across vertebrates at the molecular level. Changes in coloration that occur in adulthood via phenotypic plasticity rely on various social, visual, and dietary cues independent of genetic variation. Here, I will review the contributions of pigment cell biology to animal color changes and recent studies describing their molecular underpinnings and function. In this regard, conserved epigenetic processes such as DNA methylation play a role in lending plasticity to gene regulation as it relates to chromatophore function. Lastly, I will present African cichlids as emerging models for the study of pigmentation and molecular plasticity for animal color changes. I posit that these processes, in a dialog with environmental stimuli, are important regulators of variation and the selective advantages that accompany a change in coloration for vertebrate animals.
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121
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He X, Xu W, Ding F, Xu C, Li Y, Chen H, Shen J. Reaction-Based Ratiometric and Colorimetric Chemosensor for Bioimaging of Biosulfite in Live Cells, Zebrafish, and Food Samples. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:11774-11781. [PMID: 32886514 DOI: 10.1021/acs.jafc.0c03983] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
In this work, a reaction-based ratiometric and colorimetric sensor was designed and synthesized for probing bisulfite (HSO3-) by coupling coumarin (CM) with barbituric (BA) moiety. Further tests have shown that CM-BA has high selectivity and sensitivity for the recognition of HSO3-, which can be applied for the detection of HSO3- in environmental and biological systems very effectively. The fluorescence intensity ratios (F462/F568) exhibited an outstanding HSO3--dependent response with ultrafast response time (within 20 s) and a lower detection limit (105 nM). Meanwhile, the color of the CM-BA solution changed from green to colorless during the recognition process, and its fluorescence changed from green to blue. The mechanism of response is confirmed by the density functional theory (DFT) model. In summary, CM-BA has demonstrated low toxicity and good permeability, which can be applied for imaging HSO3- in cells and zebrafish safely and effectively. Besides, this novel sensor CM-BA successfully realized the quantification of the concentration of HSO3- in paper strips and food samples.
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Affiliation(s)
- Xiaojun He
- School of Ophthalmology & Optometry, School of Biomedical Engineering, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Wei Xu
- School of Ophthalmology & Optometry, School of Biomedical Engineering, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Feng Ding
- Department of Microbiology & Immunology, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Chuchu Xu
- School of Stomatology, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Yahui Li
- School of Ophthalmology & Optometry, School of Biomedical Engineering, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Hong Chen
- Luoyang Key Laboratory of Organic Functional Molecules, College of Food and Drug, Luoyang Normal University, Luoyang, Henan 471934, China
| | - Jianliang Shen
- School of Ophthalmology & Optometry, School of Biomedical Engineering, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
- Engineering Research Center of Clinical Functional Materials and Diagnosis & Treatment Devices of Zhejiang Province, Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, Zhejiang 325001, China
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122
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Msuite: A High-Performance and Versatile DNA Methylation Data-Analysis Toolkit. PATTERNS 2020; 1:100127. [PMID: 33294868 PMCID: PMC7691389 DOI: 10.1016/j.patter.2020.100127] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 09/08/2020] [Accepted: 09/16/2020] [Indexed: 12/28/2022]
Abstract
DNA methylation is a pervasive and important epigenetic regulator in mammalian genome. For DNA methylome profiling, emerging bisulfite-free methods have demonstrated desirable superiority over the conventional bisulfite-treatment-based approaches, although current analysis software could not make full use of their advantages. In this work, we present Msuite, an easy-to-use, all-in-one data-analysis toolkit. Msuite implements a unique 4-letter analysis mode specifically optimized for emerging protocols; it also integrates quality controls, methylation call, and data visualizations. Msuite demonstrates substantial performance improvements over current state-of-the-art tools as well as fruitful functionalities, thus holding the potential to serve as an optimal toolkit to facilitate DNA methylome studies. Source codes and testing datasets for Msuite are freely available at https://github.com/hellosunking/Msuite/. Msuite provides a unique 4-letter analysis mode for emerging bisulfite-free protocols Msuite outperforms current tools in terms of higher accuracy and lower resource usage Msuite has integrated quality control and fruitful data-visualization utilities Msuite provides an all-in-one solution for DNA methylation data analysis
DNA methylation is an essential epigenetic modification responsible for many biological regulation pathways. Despite the fact that various high-throughput methods have been developed for base-resolution DNA methylome profiling, DNA methylation data analysis remains a complex and challenging task. Here, we present Msuite, which has integrated quality control, read alignment, methylation call, and fruitful data-visualization functionalities, aiming to offer an all-in-one package for most of the current DNA methylation profiling assays. Msuite also provides dedicated support for emerging bisulfite-free protocols and outperforms the current tools in terms of higher accuracy and lower computational resource requirement. Hence, Msuite could serve as the optimal toolkit for DNA methylation data analysis as well as facilitating the popularization of emerging bisulfite-free protocols.
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123
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Li S, Tollefsbol TO. DNA methylation methods: Global DNA methylation and methylomic analyses. Methods 2020; 187:28-43. [PMID: 33039572 DOI: 10.1016/j.ymeth.2020.10.002] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Revised: 10/02/2020] [Accepted: 10/05/2020] [Indexed: 12/13/2022] Open
Abstract
DNA methylation provides a pivotal layer of epigenetic regulation in eukaryotes that has significant involvement for numerous biological processes in health and disease. The function of methylation of cytosine bases in DNA was originally proposed as a "silencing" epigenetic marker and focused on promoter regions of genes for decades. Improved technologies and accumulating studies have been extending our understanding of the roles of DNA methylation to various genomic contexts including gene bodies, repeat sequences and transcriptional start sites. The demand for comprehensively describing DNA methylation patterns spawns a diversity of DNA methylation profiling technologies that target its genomic distribution. These approaches have enabled the measurement of cytosine methylation from specific loci at restricted regions to single-base-pair resolution on a genome-scale level. In this review, we discuss the different DNA methylation analysis technologies primarily based on the initial treatments of DNA samples: bisulfite conversion, endonuclease digestion and affinity enrichment, involving methodology evolution, principles, applications, and their relative merits. This review may offer referable information for the selection of various platforms for genome-wide analysis of DNA methylation.
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Affiliation(s)
- Shizhao Li
- Department of Biology, University of Alabama at Birmingham, Birmingham, AL, United States.
| | - Trygve O Tollefsbol
- Department of Biology, University of Alabama at Birmingham, Birmingham, AL, United States; Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL, United States; Nutrition Obesity Research Center, University of Alabama at Birmingham, Birmingham, AL, United States; Comprehensive Center for Healthy Aging, University of Alabama at Birmingham, Birmingham, AL, United States; Comprehensive Diabetes Center, University of Alabama at Birmingham, Birmingham, AL, United States.
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124
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Feng S, Zhong Z, Wang M, Jacobsen SE. Efficient and accurate determination of genome-wide DNA methylation patterns in Arabidopsis thaliana with enzymatic methyl sequencing. Epigenetics Chromatin 2020; 13:42. [PMID: 33028374 PMCID: PMC7542392 DOI: 10.1186/s13072-020-00361-9] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 09/18/2020] [Indexed: 12/31/2022] Open
Abstract
Background 5′ methylation of cytosines in DNA molecules is an important epigenetic mark in eukaryotes. Bisulfite sequencing is the gold standard of DNA methylation detection, and whole-genome bisulfite sequencing (WGBS) has been widely used to detect methylation at single-nucleotide resolution on a genome-wide scale. However, sodium bisulfite is known to severely degrade DNA, which, in combination with biases introduced during PCR amplification, leads to unbalanced base representation in the final sequencing libraries. Enzymatic conversion of unmethylated cytosines to uracils can achieve the same end product for sequencing as does bisulfite treatment and does not affect the integrity of the DNA; enzymatic methylation sequencing may, thus, provide advantages over bisulfite sequencing. Results Using an enzymatic methyl-seq (EM-seq) technique to selectively deaminate unmethylated cytosines to uracils, we generated and sequenced libraries based on different amounts of Arabidopsis input DNA and different numbers of PCR cycles, and compared these data to results from traditional whole-genome bisulfite sequencing. We found that EM-seq libraries were more consistent between replicates and had higher mapping and lower duplication rates, lower background noise, higher average coverage, and higher coverage of total cytosines. Differential methylation region (DMR) analysis showed that WGBS tended to over-estimate methylation levels especially in CHG and CHH contexts, whereas EM-seq detected higher CG methylation levels in certain highly methylated areas. These phenomena can be mostly explained by a correlation of WGBS methylation estimation with GC content and methylated cytosine density. We used EM-seq to compare methylation between leaves and flowers, and found that CHG methylation level is greatly elevated in flowers, especially in pericentromeric regions. Conclusion We suggest that EM-seq is a more accurate and reliable approach than WGBS to detect methylation. Compared to WGBS, the results of EM-seq are less affected by differences in library preparation conditions or by the skewed base composition in the converted DNA. It may therefore be more desirable to use EM-seq in methylation studies.
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Affiliation(s)
- Suhua Feng
- Department of Molecular, Cell and Developmental Biology, University of California at Los Angeles, Los Angeles, CA, 90095, USA.,Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, University of California at Los Angeles, Los Angeles, CA, 90095, USA
| | - Zhenhui Zhong
- Department of Molecular, Cell and Developmental Biology, University of California at Los Angeles, Los Angeles, CA, 90095, USA
| | - Ming Wang
- Department of Molecular, Cell and Developmental Biology, University of California at Los Angeles, Los Angeles, CA, 90095, USA
| | - Steven E Jacobsen
- Department of Molecular, Cell and Developmental Biology, University of California at Los Angeles, Los Angeles, CA, 90095, USA. .,Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, University of California at Los Angeles, Los Angeles, CA, 90095, USA. .,Howard Hughes Medical Institute, University of California at Los Angeles, Los Angeles, CA, 90095, USA.
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125
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Jiang Q, Ang JYJ, Lee AY, Cao Q, Li KY, Yip KY, Leung DCY. G9a Plays Distinct Roles in Maintaining DNA Methylation, Retrotransposon Silencing, and Chromatin Looping. Cell Rep 2020; 33:108315. [PMID: 33113380 DOI: 10.1016/j.celrep.2020.108315] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 09/05/2020] [Accepted: 10/06/2020] [Indexed: 12/15/2022] Open
Abstract
G9a is a lysine methyltransferase that regulates epigenetic modifications, transcription, and genome organization. However, whether these properties are dependent on one another or represent distinct functions of G9a remains unclear. In this study, we observe widespread DNA methylation loss in G9a depleted and catalytic mutant embryonic stem cells. Furthermore, we define how G9a regulates chromatin accessibility, epigenetic modifications, and transcriptional silencing in both catalytic-dependent and -independent manners. Reactivated retrotransposons provide alternative promoters and splice sites leading to the upregulation of neighboring genes and the production of chimeric transcripts. Moreover, while topologically associated domains and compartment A/B definitions are largely unaffected, the loss of G9a leads to altered chromatin states, aberrant CTCF and cohesin binding, and differential chromatin looping, especially at retrotransposons. Taken together, our findings reveal how G9a regulates the epigenome, transcriptome, and higher-order chromatin structures in distinct mechanisms.
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Affiliation(s)
- Qinghong Jiang
- Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Julie Y J Ang
- Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Ah Young Lee
- Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Qin Cao
- Department of Computer Science and Engineering, The Chinese University of Hong Kong, Hong Kong, China
| | - Kelly Y Li
- Department of Computer Science and Engineering, The Chinese University of Hong Kong, Hong Kong, China
| | - Kevin Y Yip
- Department of Computer Science and Engineering, The Chinese University of Hong Kong, Hong Kong, China
| | - Danny C Y Leung
- Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong, China.
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126
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Smith AR, Wheildon G, Lunnon K. Invited Review – A 5‐year update on epigenome‐wide association studies of DNA modifications in Alzheimer’s disease: progress, practicalities and promise. Neuropathol Appl Neurobiol 2020; 46:641-653. [DOI: 10.1111/nan.12650] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 07/10/2020] [Accepted: 07/12/2020] [Indexed: 12/12/2022]
Affiliation(s)
- A. R. Smith
- University of Exeter Medical School College of Medicine and Health Exeter University Exeter UK
| | - G. Wheildon
- University of Exeter Medical School College of Medicine and Health Exeter University Exeter UK
| | - K. Lunnon
- University of Exeter Medical School College of Medicine and Health Exeter University Exeter UK
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127
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The Absence of C-5 DNA Methylation in Leishmania donovani Allows DNA Enrichment from Complex Samples. Microorganisms 2020; 8:microorganisms8081252. [PMID: 32824654 PMCID: PMC7463849 DOI: 10.3390/microorganisms8081252] [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: 07/11/2020] [Revised: 08/12/2020] [Accepted: 08/12/2020] [Indexed: 11/21/2022] Open
Abstract
Cytosine C5 methylation is an important epigenetic control mechanism in a wide array of eukaryotic organisms and generally carried out by proteins of the C-5 DNA methyltransferase family (DNMTs). In several protozoans, the status of this mechanism remains elusive, such as in Leishmania, the causative agent of the disease leishmaniasis in humans and a wide array of vertebrate animals. In this work, we showed that the Leishmania donovani genome contains a C-5 DNA methyltransferase (DNMT) from the DNMT6 subfamily, whose function is still unclear, and verified its expression at the RNA level. We created viable overexpressor and knock-out lines of this enzyme and characterized their genome-wide methylation patterns using whole-genome bisulfite sequencing, together with promastigote and amastigote control lines. Interestingly, despite the DNMT6 presence, we found that methylation levels were equal to or lower than 0.0003% at CpG sites, 0.0005% at CHG sites, and 0.0126% at CHH sites at the genomic scale. As none of the methylated sites were retained after manual verification, we conclude that there is no evidence for DNA methylation in this species. We demonstrated that this difference in DNA methylation between the parasite (no detectable DNA methylation) and the vertebrate host (DNA methylation) allowed enrichment of parasite vs. host DNA using methyl-CpG-binding domain columns, readily available in commercial kits. As such, we depleted methylated DNA from mixes of Leishmania promastigote and amastigote DNA with human DNA, resulting in average Leishmania:human enrichments from 62× up to 263×. These results open a promising avenue for unmethylated DNA enrichment as a pre-enrichment step before sequencing Leishmania clinical samples.
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128
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Smigielski L, Jagannath V, Rössler W, Walitza S, Grünblatt E. Epigenetic mechanisms in schizophrenia and other psychotic disorders: a systematic review of empirical human findings. Mol Psychiatry 2020; 25:1718-1748. [PMID: 31907379 DOI: 10.1038/s41380-019-0601-3] [Citation(s) in RCA: 77] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 11/05/2019] [Accepted: 11/07/2019] [Indexed: 12/26/2022]
Abstract
Schizophrenia and other psychotic disorders are highly debilitating psychiatric conditions that lack a clear etiology and exhibit polygenic inheritance underlain by pleiotropic genes. The prevailing explanation points to the interplay between predisposing genes and environmental exposure. Accumulated evidence suggests that epigenetic regulation of the genome may mediate dynamic gene-environment interactions at the molecular level by modulating the expression of psychiatric phenotypes through transcription factors. This systematic review summarizes the current knowledge linking schizophrenia and other psychotic disorders to epigenetics, based on PubMed and Web of Science database searches conducted according to the PRISMA guidelines. Three groups of mechanisms in case-control studies of human tissue (i.e., postmortem brain and bio-fluids) were considered: DNA methylation, histone modifications, and non-coding miRNAs. From the initial pool of 3,204 records, 152 studies met our inclusion criteria (11,815/11,528, 233/219, and 2,091/1,827 cases/controls for each group, respectively). Many of the findings revealed associations with epigenetic modulations of genes regulating neurotransmission, neurodevelopment, and immune function, as well as differential miRNA expression (e.g., upregulated miR-34a, miR-7, and miR-181b). Overall, actual evidence moderately supports an association between epigenetics and schizophrenia and other psychotic disorders. However, heterogeneous results and cross-tissue extrapolations call for future work. Integrating epigenetics into systems biology may critically enhance research on psychosis and thus our understanding of the disorder. This may have implications for psychiatry in risk stratification, early recognition, diagnostics, precision medicine, and other interventional approaches targeting epigenetic fingerprints.
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Affiliation(s)
- Lukasz Smigielski
- Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital of Psychiatry Zurich, University of Zurich, Zurich, Switzerland. .,The Zurich Program for Sustainable Development of Mental Health Services (ZInEP), University Hospital of Psychiatry Zurich, Zurich, Switzerland.
| | - Vinita Jagannath
- Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital of Psychiatry Zurich, University of Zurich, Zurich, Switzerland.,Merck Sharp & Dohme (MSD) R&D Innovation Centre, London, UK
| | - Wulf Rössler
- The Zurich Program for Sustainable Development of Mental Health Services (ZInEP), University Hospital of Psychiatry Zurich, Zurich, Switzerland.,Department of Psychiatry, Psychotherapy and Psychosomatics, University Hospital of Psychiatry, University of Zurich, Zurich, Switzerland.,Department of Psychiatry and Psychotherapy, Charité Universitätsmedizin, Berlin, Germany.,Laboratory of Neuroscience, Institute of Psychiatry, Universidade de São Paulo, São Paulo, Brazil
| | - Susanne Walitza
- Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital of Psychiatry Zurich, University of Zurich, Zurich, Switzerland.,The Zurich Program for Sustainable Development of Mental Health Services (ZInEP), University Hospital of Psychiatry Zurich, Zurich, Switzerland.,Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland.,Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Edna Grünblatt
- Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital of Psychiatry Zurich, University of Zurich, Zurich, Switzerland.,Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland.,Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
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Erger F, Nörling D, Borchert D, Leenen E, Habbig S, Wiesener MS, Bartram MP, Wenzel A, Becker C, Toliat MR, Nürnberg P, Beck BB, Altmüller J. cfNOMe - A single assay for comprehensive epigenetic analyses of cell-free DNA. Genome Med 2020; 12:54. [PMID: 32580754 PMCID: PMC7315486 DOI: 10.1186/s13073-020-00750-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Accepted: 06/02/2020] [Indexed: 02/07/2023] Open
Abstract
Cell-free DNA (cfDNA) analysis has become essential in cancer diagnostics and prenatal testing. We present cfNOMe, a two-in-one method of measuring cfDNA cytosine methylation and nucleosome occupancy in a single assay using non-disruptive enzymatic cytosine conversion and a custom bioinformatic pipeline. We show that enzymatic cytosine conversion better preserves cfDNA fragmentation information than does bisulfite conversion. Whereas previously separate experiments were required to study either epigenetic marking, cfNOMe delivers reliable results for both, enabling more comprehensive and inexpensive epigenetic cfDNA profiling. cfNOMe has the potential to advance biomarker discovery and diagnostic usage in diseases with systemic perturbations of cfDNA composition.
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Affiliation(s)
- Florian Erger
- Cologne Center for Genomics, University of Cologne, Cologne, Germany. .,Institute of Human Genetics, Faculty of Medicine and University Hospital Cologne, Cologne, Germany. .,Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany.
| | - Deborah Nörling
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Domenica Borchert
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Esther Leenen
- Department of Nephrology, Transplantation and Medical Intensive Care, University Witten/Herdecke, Medical Center Cologne-Merheim, Cologne, Germany
| | - Sandra Habbig
- Department of Pediatrics, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Michael S Wiesener
- Department of Nephrology and Hypertension, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Malte P Bartram
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany.,Department II of Internal Medicine, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Andrea Wenzel
- Institute of Human Genetics, Faculty of Medicine and University Hospital Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Christian Becker
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Mohammad R Toliat
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Peter Nürnberg
- Cologne Center for Genomics, University of Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Bodo B Beck
- Institute of Human Genetics, Faculty of Medicine and University Hospital Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Janine Altmüller
- Cologne Center for Genomics, University of Cologne, Cologne, Germany. .,Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany.
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130
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Teschendorff AE. A comparison of epigenetic mitotic-like clocks for cancer risk prediction. Genome Med 2020; 12:56. [PMID: 32580750 PMCID: PMC7315560 DOI: 10.1186/s13073-020-00752-3] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Accepted: 06/10/2020] [Indexed: 12/19/2022] Open
Abstract
Background DNA methylation changes that accrue in the stem cell pool of an adult tissue in line with the cumulative number of cell divisions may contribute to the observed variation in cancer risk among tissues and individuals. Thus, the construction of epigenetic “mitotic” clocks that can measure the lifetime number of stem cell divisions is of paramount interest. Methods Building upon a dynamic model of DNA methylation gain in unmethylated CpG-rich regions, we here derive a novel mitotic clock (“epiTOC2”) that can directly estimate the cumulative number of stem cell divisions in a tissue. We compare epiTOC2 to a different mitotic model, based on hypomethylation at solo-WCGW sites (“HypoClock”), in terms of their ability to measure mitotic age of normal adult tissues and predict cancer risk. Results Using epiTOC2, we estimate the intrinsic stem cell division rate for different normal tissue types, demonstrating excellent agreement (Pearson correlation = 0.92, R2 = 0.85, P = 3e−6) with those derived from experiment. In contrast, HypoClock’s estimates do not (Pearson correlation = 0.30, R2 = 0.09, P = 0.29). We validate these results in independent datasets profiling normal adult tissue types. While both epiTOC2 and HypoClock correctly predict an increased mitotic rate in cancer, epiTOC2 is more robust and significantly better at discriminating preneoplastic lesions characterized by chronic inflammation, a major driver of tissue turnover and cancer risk. Our data suggest that DNA methylation loss at solo-WCGWs is significant only when cells are under high replicative stress and that epiTOC2 is a better mitotic age and cancer risk prediction model for normal adult tissues. Conclusions These results have profound implications for our understanding of epigenetic clocks and for developing cancer risk prediction or early detection assays. We propose that measurement of DNAm at the 163 epiTOC2 CpGs in adult pre-neoplastic lesions, and potentially in serum cell-free DNA, could provide the basis for building feasible pre-diagnostic or cancer risk assays. epiTOC2 is freely available from 10.5281/zenodo.2632938
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Affiliation(s)
- Andrew E Teschendorff
- CAS Key Laboratory of Computational Biology, CAS-MPG Partner Institute for Computational Biology, Shanghai Institute of Nutrition and Health, Shanghai Institute for Biological Sciences, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai, 200031, China. .,UCL Cancer Institute, University College London, 72 Huntley Street, London, WC1E 6BT, UK.
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131
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Lam D, Luu PL, Song JZ, Qu W, Risbridger GP, Lawrence MG, Lu J, Trau M, Korbie D, Clark SJ, Pidsley R, Stirzaker C. Comprehensive evaluation of targeted multiplex bisulphite PCR sequencing for validation of DNA methylation biomarker panels. Clin Epigenetics 2020; 12:90. [PMID: 32571390 PMCID: PMC7310104 DOI: 10.1186/s13148-020-00880-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 06/04/2020] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND DNA methylation is a well-studied epigenetic mark that is frequently altered in diseases such as cancer, where specific changes are known to reflect the type and severity of the disease. Therefore, there is a growing interest in assessing the clinical utility of DNA methylation as a biomarker for diagnosing disease and guiding treatment. The development of an accurate loci-specific methylation assay, suitable for use on low-input clinical material, is crucial for advancing DNA methylation biomarkers into a clinical setting. A targeted multiplex bisulphite PCR sequencing approach meets these needs by allowing multiple DNA methylated regions to be interrogated simultaneously in one experiment on limited clinical material. RESULTS Here, we provide an updated protocol and recommendations for multiplex bisulphite PCR sequencing (MBPS) assays for target DNA methylation analysis. We describe additional steps to improve performance and reliability: (1) pre-sequencing PCR optimisation which includes assessing the optimal PCR cycling temperature and primer concentration and (2) post-sequencing PCR optimisation to achieve uniform coverage of each amplicon. We use a gradient of methylated controls to demonstrate how PCR bias can be assessed and corrected. Methylated controls also allow assessment of the sensitivity of methylation detection for each amplicon. Here, we show that the MBPS assay can amplify as little as 0.625 ng starting DNA and can detect methylation differences of 1% with a sequencing coverage of 1000 reads. Furthermore, the multiplex bisulphite PCR assay can comprehensively interrogate multiple regions on 1-5 ng of formalin-fixed paraffin-embedded DNA or circulating cell-free DNA. CONCLUSIONS The MBPS assay is a valuable approach for assessing methylated DNA regions in clinical samples with limited material. The optimisation and additional quality control steps described here improve the performance and reliability of this method, advancing it towards potential clinical applications in biomarker studies.
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Affiliation(s)
- Dilys Lam
- Epigenetics Research Laboratory, Genomics and Epigenetics Division, Garvan Institute of Medical Research, Sydney, New South Wales, 2010, Australia
| | - Phuc-Loi Luu
- Epigenetics Research Laboratory, Genomics and Epigenetics Division, Garvan Institute of Medical Research, Sydney, New South Wales, 2010, Australia
- St Vincent's Clinical School, UNSW Sydney, Sydney, New South Wales, 2010, Australia
| | - Jenny Z Song
- Epigenetics Research Laboratory, Genomics and Epigenetics Division, Garvan Institute of Medical Research, Sydney, New South Wales, 2010, Australia
| | - Wenjia Qu
- Epigenetics Research Laboratory, Genomics and Epigenetics Division, Garvan Institute of Medical Research, Sydney, New South Wales, 2010, Australia
| | - Gail P Risbridger
- Monash Partners Comprehensive Cancer Consortium, Monash Biomedicine Discovery Institute Cancer Program, Prostate Cancer Research Group, Department of Anatomy and Developmental Biology, Monash University, Clayton, VIC, 3800, Australia
- Cancer Research Division, Peter MacCallum Cancer Centre, Melbourne, VIC, 3000, Australia
- Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Mitchell G Lawrence
- Monash Partners Comprehensive Cancer Consortium, Monash Biomedicine Discovery Institute Cancer Program, Prostate Cancer Research Group, Department of Anatomy and Developmental Biology, Monash University, Clayton, VIC, 3800, Australia
- Cancer Research Division, Peter MacCallum Cancer Centre, Melbourne, VIC, 3000, Australia
- Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Jennifer Lu
- Centre for Personalised Nanomedicine, Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, St Lucia, Queensland, 4072, Australia
| | - Matt Trau
- Centre for Personalised Nanomedicine, Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, St Lucia, Queensland, 4072, Australia
| | - Darren Korbie
- Centre for Personalised Nanomedicine, Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, St Lucia, Queensland, 4072, Australia
| | - Susan J Clark
- Epigenetics Research Laboratory, Genomics and Epigenetics Division, Garvan Institute of Medical Research, Sydney, New South Wales, 2010, Australia
- St Vincent's Clinical School, UNSW Sydney, Sydney, New South Wales, 2010, Australia
| | - Ruth Pidsley
- Epigenetics Research Laboratory, Genomics and Epigenetics Division, Garvan Institute of Medical Research, Sydney, New South Wales, 2010, Australia.
- St Vincent's Clinical School, UNSW Sydney, Sydney, New South Wales, 2010, Australia.
| | - Clare Stirzaker
- Epigenetics Research Laboratory, Genomics and Epigenetics Division, Garvan Institute of Medical Research, Sydney, New South Wales, 2010, Australia.
- St Vincent's Clinical School, UNSW Sydney, Sydney, New South Wales, 2010, Australia.
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132
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Wu P, Gao Y, Guo W, Zhu P. Using local alignment to enhance single-cell bisulfite sequencing data efficiency. Bioinformatics 2020; 35:3273-3278. [PMID: 30859188 DOI: 10.1093/bioinformatics/btz125] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 01/29/2019] [Accepted: 02/15/2019] [Indexed: 11/14/2022] Open
Abstract
MOTIVATION Single-cell bisulfite sequencing (BS-seq) techniques have been developed for DNA methylation heterogeneity detection and studies with limited materials. However, the data deficiency such as low read mapping ratio is still a critical issue. RESULTS We comprehensively characterize single-cell BS-seq data and reveal chimerical molecules to be the major source of alignment failures. These chimerical molecules are produced by recombination of genomic proximal sequences with microhomology regions (MR) after bisulfite conversion. In addition, we find DNA methylation within MR is highly variable, suggesting the necessity of removing these regions to accurately estimate DNA methylation levels. We further develop scBS-map to perform quality control and local alignment of bisulfite sequencing data, chimerical molecule determination and MR removal. Using scBS-map, we show remarkable increases in uniquely mapped reads, genomic coverage and number of CpG sites, and recover more functional elements with precise DNA methylation estimation. AVAILABILITY AND IMPLEMENTATION The scBS-map software is freely available at https://github.com/wupengomics/scBS-map. SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Peng Wu
- State Key Laboratory of Experimental Hematology, Institute of Hematology and Blood Disease Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, China.,Center for Stem Cell Medicine, Chinese Academy of Medical Sciences, Tianjin, China.,Department of Stem Cell & Regenerative Medicine, Peking Union Medical College, Tianjin, China
| | - Yan Gao
- Center for Breast Cancer Prevention and TherapyTianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin, China.,Key Laboratory of Cancer Prevention and Therapy, Tianjin, China.,Tianjin's Clinical Research Center for Cancer, Tianjin, China.,Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin, China
| | - Weilong Guo
- State Key Laboratory for Agrobiotechnology, College of Agronomy and Biotechnology, China Agricultural University, Beijing, China
| | - Ping Zhu
- State Key Laboratory of Experimental Hematology, Institute of Hematology and Blood Disease Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, China.,Center for Stem Cell Medicine, Chinese Academy of Medical Sciences, Tianjin, China.,Department of Stem Cell & Regenerative Medicine, Peking Union Medical College, Tianjin, China
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133
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Development and optimization of the VISAGE basic prototype tool for forensic age estimation. Forensic Sci Int Genet 2020; 48:102322. [PMID: 32574993 DOI: 10.1016/j.fsigen.2020.102322] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 04/22/2020] [Accepted: 06/03/2020] [Indexed: 01/03/2023]
Abstract
The VISAGE (VISible Attributes through GEnomics) consortium aims to develop, optimize and validate prototype tools to broaden the use of DNA intelligence methods in forensic routine laboratories. This includes age estimation based on the quantification of DNA methylation at specific CpG sites. Here, we present the VISAGE basic prototype tool for age estimation targeting 32 CpGs from five genes ELOVL2, MIR29B2CHG (herein, MIR29B2C), FHL2, TRIM59 and KLF14. The assay interrogates these well described age markers by multiplex PCR for bisulfite converted DNA and massively parallel sequencing on a MiSeq FGx instrument. We describe protocol optimizations including tests on five bisulfite conversion kits and an evaluation of the assay's reproducibility and sensitivity with artificially methylated DNA standards. We observed robust quantification of methylation levels with a mean standard deviation of 1.4 % across ratios. Sensitivity tests showed no increase of variability down to 20 ng DNA input into bisulfite conversion with a median difference below 1.6 % between technical replicates.
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134
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Enhancer DNA methylation: implications for gene regulation. Essays Biochem 2020; 63:707-715. [PMID: 31551326 DOI: 10.1042/ebc20190030] [Citation(s) in RCA: 77] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 09/08/2019] [Accepted: 09/10/2019] [Indexed: 12/13/2022]
Abstract
DNA methylation involves the addition of a methyl group to the fifth carbon of the pyrimidine cytosine ring (5-methylcytosine, 5mC). 5mC is widespread in vertebrate genomes where it is predominantly found within CpG dinucleotides. In mammals, 5mC participates in long-term silencing processes such as X-chromosome inactivation, genomic imprinting, somatic silencing of germline genes, and silencing of repetitive DNA elements. The evidence for 5mC as a dynamic gene-regulatory mechanism is mostly limited to specific examples, and is far from being completely understood. Recent work from diverse model systems suggests that 5mC might not always act as a dominant repressive mechanism and that hypermethylated promoters and enhancers can be permissive to transcription in vivo and in vitro. In this review, we discuss the links between 5mC and enhancer activity, and evaluate the role of this biochemical mechanism in various biological contexts.
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135
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Peng X, Li HD, Wu FX, Wang J. Identifying the tissues-of-origin of circulating cell-free DNAs is a promising way in noninvasive diagnostics. Brief Bioinform 2020; 22:5840077. [PMID: 32427285 DOI: 10.1093/bib/bbaa060] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 03/16/2020] [Accepted: 03/25/2020] [Indexed: 12/18/2022] Open
Abstract
Advances in sequencing technologies facilitate personalized disease-risk profiling and clinical diagnosis. In recent years, some great progress has been made in noninvasive diagnoses based on cell-free DNAs (cfDNAs). It exploits the fact that dead cells release DNA fragments into the circulation, and some DNA fragments carry information that indicates their tissues-of-origin (TOOs). Based on the signals used for identifying the TOOs of cfDNAs, the existing methods can be classified into three categories: cfDNA mutation-based methods, methylation pattern-based methods and cfDNA fragmentation pattern-based methods. In cfDNA mutation-based methods, the SNP information or the detected mutations in driven genes of certain diseases are employed to identify the TOOs of cfDNAs. Methylation pattern-based methods are developed to identify the TOOs of cfDNAs based on the tissue-specific methylation patterns. In cfDNA fragmentation pattern-based methods, cfDNA fragmentation patterns, such as nucleosome positioning or preferred end coordinates of cfDNAs, are used to predict the TOOs of cfDNAs. In this paper, the strategies and challenges in each category are reviewed. Furthermore, the representative applications based on the TOOs of cfDNAs, including noninvasive prenatal testing, noninvasive cancer screening, transplantation rejection monitoring and parasitic infection detection, are also reviewed. Moreover, the challenges and future work in identifying the TOOs of cfDNAs are discussed. Our research provides a comprehensive picture of the development and challenges in identifying the TOOs of cfDNAs, which may benefit bioinformatics researchers to develop new methods to improve the identification of the TOOs of cfDNAs.
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137
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Zhang Z, Yan J, Li Z. Peroxotungstate oxidation-mediated two-phase amplification system (POM-TPAS) for bisulfite-free quantification of locus-specific 5-hydroxymethylcytosine. Chem Commun (Camb) 2020; 56:3111-3114. [PMID: 32090228 DOI: 10.1039/d0cc00167h] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The peroxotungstate oxidation-mediated two-phase amplification system (POM-TPAS) is applied for the first time to the sensitive detection of locus-specific 5-hydroxymethylcytosine (5hmC) in DNA with low non-specific amplification. This strategy greatly shortens reaction time, improves sensitivity, and reduces non-specific amplification.
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Affiliation(s)
- Zhenhao Zhang
- Key Laboratory of Applied Surface and Colloid Chemistry Ministry of Education, Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710062, Shaanxi Province, P. R. China.
| | - Jingli Yan
- Key Laboratory of Applied Surface and Colloid Chemistry Ministry of Education, Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710062, Shaanxi Province, P. R. China.
| | - Zhengping Li
- Key Laboratory of Applied Surface and Colloid Chemistry Ministry of Education, Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710062, Shaanxi Province, P. R. China.
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138
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Liu C, Cui X, Zhao BS, Narkhede P, Gao Y, Liu J, Dou X, Dai Q, Zhang LS, He C. DNA 5-Methylcytosine-Specific Amplification and Sequencing. J Am Chem Soc 2020; 142:4539-4543. [PMID: 32077696 DOI: 10.1021/jacs.9b12707] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
DNA 5-methylcytosine (5mC)-specific mapping has been hampered by severe DNA degradation and the presence of 5-hydroxymethylcytosine (5hmC) using the conventional bisulfite sequencing approach. Here, we present a 5mC-specific whole-genome amplification method (5mC-WGA), with which we achieved 5mC retention during DNA amplification from limited input down to 10 pg scale with limited interference from 5hmC signals, providing DNA 5mC methylome with high reproducibility and accuracy.
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Affiliation(s)
- Chang Liu
- Department of Chemistry, Department of Biochemistry and Molecular Biology, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, United States.,Howard Hughes Medical Institute, The University of Chicago, Chicago, Illinois 60637, United States
| | - Xiaolong Cui
- Department of Chemistry, Department of Biochemistry and Molecular Biology, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, United States.,Howard Hughes Medical Institute, The University of Chicago, Chicago, Illinois 60637, United States
| | - Boxuan Simen Zhao
- Department of Genetics, Stanford University, Stanford, California 94305, United States
| | - Pradnya Narkhede
- Department of Chemistry, University of Cambridge, Cambridge CB2 0SP, U.K
| | - Yawei Gao
- Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Jun Liu
- Department of Chemistry, Department of Biochemistry and Molecular Biology, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, United States.,Howard Hughes Medical Institute, The University of Chicago, Chicago, Illinois 60637, United States
| | - Xiaoyang Dou
- Department of Chemistry, Department of Biochemistry and Molecular Biology, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, United States.,Howard Hughes Medical Institute, The University of Chicago, Chicago, Illinois 60637, United States
| | - Qing Dai
- Department of Chemistry, Department of Biochemistry and Molecular Biology, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, United States.,Howard Hughes Medical Institute, The University of Chicago, Chicago, Illinois 60637, United States
| | - Li-Sheng Zhang
- Department of Chemistry, Department of Biochemistry and Molecular Biology, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, United States.,Howard Hughes Medical Institute, The University of Chicago, Chicago, Illinois 60637, United States
| | - Chuan He
- Department of Chemistry, Department of Biochemistry and Molecular Biology, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, United States.,Howard Hughes Medical Institute, The University of Chicago, Chicago, Illinois 60637, United States
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139
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García-Gutiérrez MS, Navarrete F, Sala F, Gasparyan A, Austrich-Olivares A, Manzanares J. Biomarkers in Psychiatry: Concept, Definition, Types and Relevance to the Clinical Reality. Front Psychiatry 2020; 11:432. [PMID: 32499729 PMCID: PMC7243207 DOI: 10.3389/fpsyt.2020.00432] [Citation(s) in RCA: 116] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 04/28/2020] [Indexed: 12/12/2022] Open
Abstract
During the last years, an extraordinary effort has been made to identify biomarkers as potential tools for improving prevention, diagnosis, drug response and drug development in psychiatric disorders. Contrary to other diseases, mental illnesses are classified by diagnostic categories with a broad variety list of symptoms. Consequently, patients diagnosed from the same psychiatric illness present a great heterogeneity in their clinical presentation. This fact together with the incomplete knowledge of the neurochemical alterations underlying mental disorders, contribute to the limited efficacy of current pharmacological options. In this respect, the identification of biomarkers in psychiatry is becoming essential to facilitate diagnosis through the developing of markers that allow to stratify groups within the syndrome, which in turn may lead to more focused treatment options. In order to shed light on this issue, this review summarizes the concept and types of biomarkers including an operational definition for therapeutic development. Besides, the advances in this field were summarized and sorted into five categories, which include genetics, transcriptomics, proteomics, metabolomics, and epigenetics. While promising results were achieved, there is a lack of biomarker investigations especially related to treatment response to psychiatric conditions. This review includes a final conclusion remarking the future challenges required to reach the goal of developing valid, reliable and broadly-usable biomarkers for psychiatric disorders and their treatment. The identification of factors predicting treatment response will reduce trial-and-error switches of medications facilitating the discovery of new effective treatments, being a crucial step towards the establishment of greater personalized medicine.
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Affiliation(s)
- Maria Salud García-Gutiérrez
- Instituto de Neurociencias, Universidad Miguel Hernández-CSIC, Alicante, Spain.,Red Temática de Investigación Cooperativa en Salud (RETICS), Red de Trastornos Adictivos, Instituto de Salud Carlos III, MICINN and FEDER, Madrid, Spain
| | - Francisco Navarrete
- Instituto de Neurociencias, Universidad Miguel Hernández-CSIC, Alicante, Spain.,Red Temática de Investigación Cooperativa en Salud (RETICS), Red de Trastornos Adictivos, Instituto de Salud Carlos III, MICINN and FEDER, Madrid, Spain
| | - Francisco Sala
- Instituto de Neurociencias, Universidad Miguel Hernández-CSIC, Alicante, Spain
| | - Ani Gasparyan
- Instituto de Neurociencias, Universidad Miguel Hernández-CSIC, Alicante, Spain.,Red Temática de Investigación Cooperativa en Salud (RETICS), Red de Trastornos Adictivos, Instituto de Salud Carlos III, MICINN and FEDER, Madrid, Spain
| | | | - Jorge Manzanares
- Instituto de Neurociencias, Universidad Miguel Hernández-CSIC, Alicante, Spain.,Red Temática de Investigación Cooperativa en Salud (RETICS), Red de Trastornos Adictivos, Instituto de Salud Carlos III, MICINN and FEDER, Madrid, Spain
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140
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Merkel A, Fernández-Callejo M, Casals E, Marco-Sola S, Schuyler R, Gut IG, Heath SC. gemBS: high throughput processing for DNA methylation data from bisulfite sequencing. Bioinformatics 2019; 35:737-742. [PMID: 30137223 DOI: 10.1093/bioinformatics/bty690] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Revised: 07/18/2018] [Accepted: 08/20/2018] [Indexed: 02/07/2023] Open
Abstract
MOTIVATION DNA methylation is essential for normal embryogenesis and development in mammals and can be captured at single base pair resolution by whole genome bisulfite sequencing (WGBS). Current available analysis tools are becoming rapidly outdated as they lack sensible functionality and efficiency to handle large amounts of data now commonly created. RESULTS We developed gemBS, a fast high-throughput bioinformatics pipeline specifically designed for large scale BS-Seq analysis that combines a high performance BS-mapper (GEM3) and a variant caller specifically for BS-Seq data (BScall). gemBS provides genotype information and methylation estimates for all genomic cytosines in different contexts (CpG and non-CpG) and a set of quality reports for comprehensive and reproducible analysis. gemBS is highly modular and can be easily automated, while producing robust and accurate results. AVAILABILITY AND IMPLEMENTATION gemBS is released under the GNU GPLv3+ license. Source code and documentation are freely available from www.statgen.cat/gemBS. SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Angelika Merkel
- Centro Nacional de Análisis Genómico (CNAG-CRG), Centre de Regulacio Genómico (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Marcos Fernández-Callejo
- Centro Nacional de Análisis Genómico (CNAG-CRG), Centre de Regulacio Genómico (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Eloi Casals
- Centro Nacional de Análisis Genómico (CNAG-CRG), Centre de Regulacio Genómico (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain
| | | | - Ronald Schuyler
- Department of Immunology and Microbiology, University of Colorado, Aurora, CO, USA
| | - Ivo G Gut
- Centro Nacional de Análisis Genómico (CNAG-CRG), Centre de Regulacio Genómico (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain.,Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Simon C Heath
- Centro Nacional de Análisis Genómico (CNAG-CRG), Centre de Regulacio Genómico (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain.,Universitat Pompeu Fabra (UPF), Barcelona, Spain
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141
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Active Demethylation of Non-CpG Moieties in Animals: A Neglected Research Area. Int J Mol Sci 2019; 20:ijms20246272. [PMID: 31842376 PMCID: PMC6940975 DOI: 10.3390/ijms20246272] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 12/09/2019] [Accepted: 12/10/2019] [Indexed: 11/17/2022] Open
Abstract
The functional role of cytosine methylation in the CpG moieties of DNA, is well established in several biological functions. The interplay between CpG methylation and hypomethylation is a well-known mechanism of modulation of gene expression. However, the role of non-CpG methylation and active dynamics of demethylation is not clearly recognized. Although some evidence exists of a role of active non-CpG demethylation in the fast dynamics of transcriptional activation in animals, few studies deal with this topic. At present, active demethylation of non-CpG moieties is a neglected research area, in spite of the promise of significant novelties.
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142
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Miura F, Shibata Y, Miura M, Sangatsuda Y, Hisano O, Araki H, Ito T. Highly efficient single-stranded DNA ligation technique improves low-input whole-genome bisulfite sequencing by post-bisulfite adaptor tagging. Nucleic Acids Res 2019; 47:e85. [PMID: 31114914 PMCID: PMC6736019 DOI: 10.1093/nar/gkz435] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Revised: 04/03/2019] [Accepted: 05/07/2019] [Indexed: 12/29/2022] Open
Abstract
Whole-genome bisulfite sequencing (WGBS) is the current gold standard of methylome analysis. Post-bisulfite adaptor tagging (PBAT) is an increasingly popular WGBS protocol because of high sensitivity and low bias. PBAT originally relied on two rounds of random priming for adaptor-tagging of single-stranded DNA (ssDNA) to attain high efficiency but at a cost of library insert length. To overcome this limitation, we developed terminal deoxyribonucleotidyl transferase (TdT)-assisted adenylate connector-mediated ssDNA (TACS) ligation as an alternative to random priming. In this method, TdT attaches adenylates to the 3′-end of input ssDNA, which are then utilized by RNA ligase as an efficient connector to the ssDNA adaptor. A protocol that uses TACS ligation instead of the second random priming step substantially increased the lengths of PBAT library fragments. Moreover, we devised a dual-library strategy that splits the input DNA to prepare two libraries with reciprocal adaptor polarity, combining them prior to sequencing. This strategy ensured an ideal base–color balance to eliminate the need for DNA spike-in for color compensation, further improving the throughput and quality of WGBS. Adopting the above strategies to the HiSeq X Ten and NovaSeq 6000 platforms, we established a cost-effective, high-quality WGBS, which should accelerate various methylome analyses.
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Affiliation(s)
- Fumihito Miura
- Department of Biochemistry, Kyushu University Graduate School of Medical Sciences, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.,Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency (JST), 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Yukiko Shibata
- Department of Biochemistry, Kyushu University Graduate School of Medical Sciences, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Miki Miura
- Department of Biochemistry, Kyushu University Graduate School of Medical Sciences, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Yuhei Sangatsuda
- Department of Biochemistry, Kyushu University Graduate School of Medical Sciences, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Osamu Hisano
- Department of Biochemistry, Kyushu University Graduate School of Medical Sciences, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Hiromitsu Araki
- Department of Biochemistry, Kyushu University Graduate School of Medical Sciences, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Takashi Ito
- Department of Biochemistry, Kyushu University Graduate School of Medical Sciences, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
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143
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Werner B, Yuwono NL, Henry C, Gunther K, Rapkins RW, Ford CE, Warton K. Circulating cell-free DNA from plasma undergoes less fragmentation during bisulfite treatment than genomic DNA due to low molecular weight. PLoS One 2019; 14:e0224338. [PMID: 31652288 PMCID: PMC6814277 DOI: 10.1371/journal.pone.0224338] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 10/10/2019] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Methylation patterns in circulating cell-free DNA are potential biomarkers for cancer and other pathologies. Currently, bisulfite treatment underpins most DNA methylation analysis methods, however, it is known to fragment DNA. Circulating DNA is already short, and further fragmentation during bisulfite treatment is of concern, as it would potentially reduce the sensitivity of downstream assays. METHODS We used high molecular weight genomic DNA to compare fragmentation and recovery following bisulfite treatment with 2 commercially available kits (Qiagen). The bisulfite treated DNA was visualised on an agarose gel and quantified by qPCR. We also bisulfite treated, visualised and quantitated circulating DNA from plasma. RESULTS There was no difference in DNA fragmentation between the two kits tested, however, the Epitect Fast kit gave better recovery than the standard Epitect kit, with the same conversion efficiency. We also found that bisulfite treated circulating DNA migrates as distinct bands on agarose gels, suggesting that, in contrast to genomic DNA, it remains largely intact following treatment. Bisulfite treatment of 129 and 234 base PCR products confirmed that this was due to the short length of the circulating DNA fragments. Compared to double stranded DNA, bisulfite treated single stranded DNA gives a very weak signal on gel electrophoresis. CONCLUSIONS DNA fragmentation during bisulfite treatment does not contribute to loss of sensitivity in methylation analysis of circulating DNA. The absence of DNA fragments below approximately 170 bases from agarose gel images of purified circulating DNA raises the possibility that these fragments are single stranded following the DNA extraction step.
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Affiliation(s)
- Bonnita Werner
- School of Women’s and Children’s Health, University of New South Wales, Kensington, Sydney, Australia
| | - Nicole Laurencia Yuwono
- School of Women’s and Children’s Health, University of New South Wales, Kensington, Sydney, Australia
| | - Claire Henry
- School of Women’s and Children’s Health, University of New South Wales, Kensington, Sydney, Australia
| | - Kate Gunther
- School of Women’s and Children’s Health, University of New South Wales, Kensington, Sydney, Australia
| | - Robert William Rapkins
- School of Women’s and Children’s Health, University of New South Wales, Kensington, Sydney, Australia
| | - Caroline Elizabeth Ford
- School of Women’s and Children’s Health, University of New South Wales, Kensington, Sydney, Australia
| | - Kristina Warton
- School of Women’s and Children’s Health, University of New South Wales, Kensington, Sydney, Australia
- Genomics and Epigenetics Division, Garvan Institute of Medical Research, Darlinghurst, Sydney, Australia
- * E-mail:
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144
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Lan VTT, Trang VL, Ngan NT, Son HV, Toan NL. An Internal Control for Evaluating Bisulfite Conversion in the Analysis of Short Stature Homeobox 2 Methylation in Lung Cancer. Asian Pac J Cancer Prev 2019; 20:2435-2443. [PMID: 31450918 PMCID: PMC6852808 DOI: 10.31557/apjcp.2019.20.8.2435] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2019] [Accepted: 08/01/2019] [Indexed: 12/17/2022] Open
Abstract
Objective: The methylation status is considered as powerful diagnostic, prognostic, and predictive biomarkers. However, the limited DNA amount and conversion efficiency after bisulfite treatment are considerable hindrances in quantitative methylation analysis. In this study, we designed an artificial internal control (IC) system that contained the cytosine-free fragment (CFF) following CpG sequences of the SHOX2 promoter whose methylation status has been described as a valuable biomarker of lung cancer. Its performance in quantifying DNA recovery and bisulfite conversion efficiency as well as in detecting false-positive SHOX2 methylation was determined on samples from lung cancer patients. Material and Methods: The IC system is composed of two pConIC and pUnIC plasmids that both contain a cytosine-free (CF) sequence derived from the CFF and the CpG containing SHOX2 sequences. They are identical in sequence, except that in the ConIC insert, all cytosines have been converted into thymines. Thus, the ConIC can be used as calibrator of 100% bisulfite conversion efficiency, while the UnIC is the indicator in order to evaluate the DNA recovery, bisulfite conversion efficiency of the SHOX2 promoter sequence by quantitative real time PCR. Results: The copy number of the target sequences impacted on both DNA recovery rates and bisulfite conversion efficiency. An amount of 0.005 ng pUnIC (106 copies) showed recovery rate of 18%, similar to that of pConIC, and a bisulfite conversion efficiency of the SHOX2 reaching 98.7%. On the contrary, higher copy number of pUnIC showed incomplete conversion (<85%) and over recovery (~42%). Using this calibrator/indicator couple, we were able to detect false-positive SHOX2 methylation (3.77% instead of 0.03%) due to incomplete bisulfite conversion.Conclusion: Our results proposed a customizable internal control using the ConIC/UnIC as calibrator/indicator to quantify simultaneously and accurately the DNA recovery and bisulfite conversion efficiencies of individual sequence as well as whole genome in methylation assays, thus promoting the validation of standardized clinical DNA methylation biomarker values to progress toward clinical applications
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Affiliation(s)
| | - Vu Lan Trang
- Sorbonne Universités, UPMC Univ. Paris 06, École normale supérieure, PSL Research University, CNRS, INSERM, APHP, Laboratoire des Biomolécules (LBM), Paris, France
| | | | | | - Nguyen Linh Toan
- Department of Pathophysiology, Medical University, Ha Dong, Vietnam
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145
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Zhou L, Ng HK, Drautz-Moses DI, Schuster SC, Beck S, Kim C, Chambers JC, Loh M. Systematic evaluation of library preparation methods and sequencing platforms for high-throughput whole genome bisulfite sequencing. Sci Rep 2019; 9:10383. [PMID: 31316107 PMCID: PMC6637168 DOI: 10.1038/s41598-019-46875-5] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Accepted: 07/05/2019] [Indexed: 01/30/2023] Open
Abstract
Whole genome bisulfite sequencing (WGBS), with its ability to interrogate methylation status at single CpG site resolution epigenome-wide, is a powerful technique for use in molecular experiments. Here, we aim to advance strategies for accurate and efficient WGBS for application in future large-scale epidemiological studies. We systematically compared the performance of three WGBS library preparation methods with low DNA input requirement (Swift Biosciences Accel-NGS, Illumina TruSeq and QIAGEN QIAseq) on two state-of-the-art sequencing platforms (Illumina NovaSeq and HiSeq X), and also assessed concordance between data generated by WGBS and methylation arrays. Swift achieved the highest proportion of CpG sites assayed and effective coverage at 26x (P < 0.001). TruSeq suffered from the highest proportion of PCR duplicates, while QIAseq failed to deliver across all quality metrics. There was little difference in performance between NovaSeq and HiSeq X, with the exception of higher read duplication rate on the NovaSeq (P < 0.05), likely attributable to the higher cluster densities on its flow cells. Systematic biases exist between WGBS and methylation arrays, with lower precision observed for WGBS across the range of depths investigated. To achieve a level of precision broadly comparable to the methylation array, a minimum coverage of 100x is recommended.
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Affiliation(s)
- Li Zhou
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, 308232, Singapore
| | - Hong Kiat Ng
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, 308232, Singapore
| | - Daniela I Drautz-Moses
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, 637551, Singapore
| | - Stephan C Schuster
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, 637551, Singapore
| | - Stephan Beck
- University College London Cancer Institute, London, WC1E 6BT, United Kingdom
| | | | - John Campbell Chambers
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, 308232, Singapore.,Department of Epidemiology and Biostatistics, Imperial College London, London, W2 1PG, United Kingdom.,Department of Cardiology, Ealing Hospital, London North West Healthcare NHS Trust, Southall, UB1 3HW, United Kingdom.,Imperial College Healthcare NHS Trust, London, W12 0HS, United Kingdom
| | - Marie Loh
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, 308232, Singapore. .,Department of Epidemiology and Biostatistics, Imperial College London, London, W2 1PG, United Kingdom. .,Translational Laboratory in Genetic Medicine, Agency for Science, Technology and Research (A*STAR), Singapore, 138648, Singapore.
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146
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Ellers J, Visser M, Mariën J, Kraaijeveld K, Lammers M. The Importance of Validating the Demethylating Effect of 5-aza-2'-deoxycytidine in Model Species (A Comment on Cook et al., "DNA Methylation and Sex Allocation in the Parasitoid Wasp Nasonia vitripennis"). Am Nat 2019; 194:422-431. [PMID: 31553212 DOI: 10.1086/704247] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The use of DNA demethylating agents has been popular in epigenetic studies. Recently, Cook and colleagues, in a 2015 American Naturalist article, claimed an effect of 5-aza-2'-deoxycytidine (5-aza-dC) on the sex ratio of a parasitoid wasp without verifying its effect on DNA methylation. We repeated the 5-aza-dC feeding treatment to test its effectiveness. We used bisulfite amplicon sequencing of 10 genes that either were heavily methylated, previously showed a response to 5-aza-dC, or were suggested to regulate fatty acid synthesis epigenetically, and we demonstrate that wasps fed 5-aza-dC did not show reduced DNA methylation at these loci. Therefore, the conclusion that demethylation shifts sex ratios upward needs reconsideration.
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147
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Sun K, Jiang P, Cheng SH, Cheng THT, Wong J, Wong VWS, Ng SSM, Ma BBY, Leung TY, Chan SL, Mok TSK, Lai PBS, Chan HLY, Sun H, Chan KCA, Chiu RWK, Lo YMD. Orientation-aware plasma cell-free DNA fragmentation analysis in open chromatin regions informs tissue of origin. Genome Res 2019; 29:418-427. [PMID: 30808726 PMCID: PMC6396422 DOI: 10.1101/gr.242719.118] [Citation(s) in RCA: 134] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 01/25/2019] [Indexed: 12/14/2022]
Abstract
Cell-free DNA (cfDNA) in human plasma is a class of biomarkers with many current and potential future diagnostic applications. Recent studies have shown that cfDNA molecules are not randomly fragmented and possess information related to their tissues of origin. Pathologies causing death of cells from particular tissues result in perturbations in the relative distribution of DNA from the affected tissues. Such tissue-of-origin analysis is particularly useful in the development of liquid biopsies for cancer. It is therefore of value to accurately determine the relative contributions of the tissues to the plasma DNA pool in a simultaneous manner. In this work, we report that in open chromatin regions, cfDNA molecules show characteristic fragmentation patterns reflected by sequencing coverage imbalance and differentially phased fragment end signals. The latter refers to differences in the read densities of sequences corresponding to the orientation of the upstream and downstream ends of cfDNA molecules in relation to the reference genome. Such cfDNA fragmentation patterns preferentially occur in tissue-specific open chromatin regions where the corresponding tissues contributed DNA into the plasma. Quantitative analyses of such signals allow measurement of the relative contributions of various tissues toward the plasma DNA pool. These findings were validated by plasma DNA sequencing data obtained from pregnant women, organ transplantation recipients, and cancer patients. Orientation-aware plasma DNA fragmentation analysis therefore has potential diagnostic applications in noninvasive prenatal testing, organ transplantation monitoring, and cancer liquid biopsy.
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Affiliation(s)
- Kun Sun
- Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong SAR, 999077, China.,Department of Chemical Pathology, The Chinese University of Hong Kong, Hong Kong SAR, 999077, China
| | - Peiyong Jiang
- Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong SAR, 999077, China.,Department of Chemical Pathology, The Chinese University of Hong Kong, Hong Kong SAR, 999077, China
| | - Suk Hang Cheng
- Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong SAR, 999077, China.,Department of Chemical Pathology, The Chinese University of Hong Kong, Hong Kong SAR, 999077, China
| | - Timothy H T Cheng
- Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong SAR, 999077, China.,Department of Chemical Pathology, The Chinese University of Hong Kong, Hong Kong SAR, 999077, China
| | - John Wong
- Department of Surgery, The Chinese University of Hong Kong, Hong Kong SAR, 999077, China
| | - Vincent W S Wong
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong SAR, 999077, China
| | - Simon S M Ng
- Department of Surgery, The Chinese University of Hong Kong, Hong Kong SAR, 999077, China
| | - Brigette B Y Ma
- Department of Clinical Oncology, The Chinese University of Hong Kong, Hong Kong SAR, 999077, China
| | - Tak Y Leung
- Department of Obstetrics and Gynaecology, The Chinese University of Hong Kong, Hong Kong SAR, 999077, China
| | - Stephen L Chan
- Department of Clinical Oncology, The Chinese University of Hong Kong, Hong Kong SAR, 999077, China
| | - Tony S K Mok
- Department of Clinical Oncology, The Chinese University of Hong Kong, Hong Kong SAR, 999077, China
| | - Paul B S Lai
- Department of Surgery, The Chinese University of Hong Kong, Hong Kong SAR, 999077, China
| | - Henry L Y Chan
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong SAR, 999077, China
| | - Hao Sun
- Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong SAR, 999077, China.,Department of Chemical Pathology, The Chinese University of Hong Kong, Hong Kong SAR, 999077, China
| | - K C Allen Chan
- Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong SAR, 999077, China.,Department of Chemical Pathology, The Chinese University of Hong Kong, Hong Kong SAR, 999077, China
| | - Rossa W K Chiu
- Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong SAR, 999077, China.,Department of Chemical Pathology, The Chinese University of Hong Kong, Hong Kong SAR, 999077, China
| | - Y M Dennis Lo
- Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong SAR, 999077, China.,Department of Chemical Pathology, The Chinese University of Hong Kong, Hong Kong SAR, 999077, China
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148
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Lai KP, Wang SY, Li JW, Tong Y, Chan TF, Jin N, Tse A, Zhang JW, Wan MT, Tam N, Au DWT, Lee BY, Lee JS, Wong AST, Kong RYC, Wu RSS. Hypoxia Causes Transgenerational Impairment of Ovarian Development and Hatching Success in Fish. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:3917-3928. [PMID: 30844260 DOI: 10.1021/acs.est.8b07250] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Hypoxia is a pressing environmental problem in both marine and freshwater ecosystems globally, and this problem will be further exacerbated by global warming in the coming decades. Recently, we reported that hypoxia can cause transgenerational impairment of sperm quality and quantity in fish (in F0, F1, and F2 generations) through DNA methylome modifications. Here, we provide evidence that female fish ( Oryzias melastigma) exposed to hypoxia exhibit reproductive impairments (follicle atresia and retarded oocyte development), leading to a drastic reduction in hatching success in the F2 generation of the transgenerational group, although they have never been exposed to hypoxia. Further analyses show that the observed transgenerational impairments in ovarian functions are related to changes in the DNA methylation and expression pattern of two gene clusters that are closely associated with stress-induced cell cycle arrest and cell apoptosis. The observed epigenetic and transgenerational alterations suggest that hypoxia may pose a significant threat to the sustainability of natural fish populations.
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Affiliation(s)
- Keng Po Lai
- Department of Chemistry , The City University of Hong Kong , Hong Kong SAR , China
- State Key Laboratory of Marine Pollution , The City University of Hong Kong , Hong Kong SAR , China
| | - Simon Yuan Wang
- Division of Newborn Medicine , Children's Hospital Boston , 300 Longwood Avenue , Boston , Massachusetts 02115 , United States
- Department of Pediatrics , Harvard Medical School , Boston , Massachusetts 02115 , United States
| | - Jing Woei Li
- Department of Chemistry , The City University of Hong Kong , Hong Kong SAR , China
| | - Yin Tong
- School of Biological Sciences , The University of Hong Kong , Hong Kong SAR , China
| | - Ting Fung Chan
- School of Life Sciences , The Chinese University of Hong Kong , Hong Kong SAR , China
- Partner State Key Laboratory of Agrobiotechnology , The Chinese University of Hong Kong , Hong Kong SAR , China
| | - Nana Jin
- School of Life Sciences , The Chinese University of Hong Kong , Hong Kong SAR , China
| | - Anna Tse
- School of Biological Sciences , The University of Hong Kong , Hong Kong SAR , China
| | - Jiang Wen Zhang
- School of Biological Sciences , The University of Hong Kong , Hong Kong SAR , China
| | - Miles Teng Wan
- Department of Chemistry , The City University of Hong Kong , Hong Kong SAR , China
| | - Nathan Tam
- Department of Chemistry , The City University of Hong Kong , Hong Kong SAR , China
| | - Doris Wai Ting Au
- Department of Chemistry , The City University of Hong Kong , Hong Kong SAR , China
- State Key Laboratory of Marine Pollution , The City University of Hong Kong , Hong Kong SAR , China
| | - Bo-Young Lee
- Department of Biological Science, College of Science , Sungkyunkwan University , Suwon , South Korea
| | - Jae-Seong Lee
- Department of Biological Science, College of Science , Sungkyunkwan University , Suwon , South Korea
| | - Alice Sze Tsai Wong
- School of Biological Sciences , The University of Hong Kong , Hong Kong SAR , China
| | - Richard Yuen Chong Kong
- Department of Chemistry , The City University of Hong Kong , Hong Kong SAR , China
- State Key Laboratory of Marine Pollution , The City University of Hong Kong , Hong Kong SAR , China
| | - Rudolf Shiu Sun Wu
- State Key Laboratory of Marine Pollution , The City University of Hong Kong , Hong Kong SAR , China
- Department of Science and Environmental Studies , The Education University of Hong Kong , Hong Kong SAR , China
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149
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Liu Y, Siejka-Zielińska P, Velikova G, Bi Y, Yuan F, Tomkova M, Bai C, Chen L, Schuster-Böckler B, Song CX. Bisulfite-free direct detection of 5-methylcytosine and 5-hydroxymethylcytosine at base resolution. Nat Biotechnol 2019; 37:424-429. [PMID: 30804537 DOI: 10.1038/s41587-019-0041-2] [Citation(s) in RCA: 217] [Impact Index Per Article: 43.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 01/22/2019] [Indexed: 02/07/2023]
Abstract
Bisulfite sequencing has been the gold standard for mapping DNA modifications including 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC) for decades1-4. However, this harsh chemical treatment degrades the majority of the DNA and generates sequencing libraries with low complexity2,5,6. Here, we present a bisulfite-free and base-level-resolution sequencing method, TET-assisted pyridine borane sequencing (TAPS), for detection of 5mC and 5hmC. TAPS combines ten-eleven translocation (TET) oxidation of 5mC and 5hmC to 5-carboxylcytosine (5caC) with pyridine borane reduction of 5caC to dihydrouracil (DHU). Subsequent PCR converts DHU to thymine, enabling a C-to-T transition of 5mC and 5hmC. TAPS detects modifications directly with high sensitivity and specificity, without affecting unmodified cytosines. This method is nondestructive, preserving DNA fragments over 10 kilobases long. We applied TAPS to the whole-genome mapping of 5mC and 5hmC in mouse embryonic stem cells and show that, compared with bisulfite sequencing, TAPS results in higher mapping rates, more even coverage and lower sequencing costs, thus enabling higher quality, more comprehensive and cheaper methylome analyses.
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Affiliation(s)
- Yibin Liu
- Ludwig Institute for Cancer Research, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Paulina Siejka-Zielińska
- Ludwig Institute for Cancer Research, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Gergana Velikova
- Ludwig Institute for Cancer Research, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Ying Bi
- Ludwig Institute for Cancer Research, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Fang Yuan
- Ludwig Institute for Cancer Research, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Peking University, Beijing, China
| | - Marketa Tomkova
- Ludwig Institute for Cancer Research, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Chunsen Bai
- Ludwig Institute for Cancer Research, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- College of Chemistry, Nankai University, Tianjin, China
| | - Lei Chen
- Ludwig Institute for Cancer Research, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Center for Mitochondrial Biology and Medicine and Center for Translational Medicine, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Benjamin Schuster-Böckler
- Ludwig Institute for Cancer Research, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
| | - Chun-Xiao Song
- Ludwig Institute for Cancer Research, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
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150
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Olova N, Krueger F, Andrews S, Oxley D, Berrens RV, Branco MR, Reik W. Correction to: Comparison of whole-genome bisulfite sequencing library preparation strategies identifies sources of biases affecting DNA methylation data. Genome Biol 2019; 20:43. [PMID: 30795792 PMCID: PMC6385436 DOI: 10.1186/s13059-019-1656-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 02/14/2019] [Indexed: 11/10/2022] Open
Abstract
Following publication of the original article [1], it was reported that the incorrect "Additional file 3" was published. The correct additional file is given below.
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Affiliation(s)
- Nelly Olova
- Epigenetics Programme, The Babraham Institute, Cambridge, CB22 3AT, UK.,Present address: MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, EH4 2XU, UK
| | - Felix Krueger
- Bioinformatics Group, The Babraham Institute, Cambridge, CB22 3AT, UK
| | - Simon Andrews
- Bioinformatics Group, The Babraham Institute, Cambridge, CB22 3AT, UK
| | - David Oxley
- Mass Spectrometry Facility, The Babraham Institute, Cambridge, CB22 3AT, UK
| | - Rebecca V Berrens
- Epigenetics Programme, The Babraham Institute, Cambridge, CB22 3AT, UK
| | - Miguel R Branco
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, E1 2AT, London, UK.
| | - Wolf Reik
- Epigenetics Programme, The Babraham Institute, Cambridge, CB22 3AT, UK. .,Wellcome Trust Sanger Institute, Hinxton, CB10 1SA, UK. .,Centre for Trophoblast Research, University of Cambridge, Cambridge, CB2 3EG, UK.
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