The DNA methylation landscape in cancer

Abstract As one of the most abundant and well-studied epigenetic modifications, DNA methylation plays an essential role in normal development and cellular biology. Global alterations to the DNA methylation landscape contribute to alterations in the transcriptome and deregulation of cellular pathways. Indeed, improved methods to study DNA methylation patterning and dynamics at base pair resolution and across individual DNA molecules on a genome-wide scale has highlighted the scope of change to the DNA methylation landscape in disease states, particularly during tumorigenesis. More recently has been the development of DNA hydroxymethylation profiling techniques, which allows differentiation between 5mC and 5hmC profiles and provides further insights into DNA methylation dynamics and remodeling in tumorigenesis. In this review, we describe the distribution of DNA methylation and DNA hydroxymethylation in different genomic contexts, first in normal cells, and how this is altered in cancer. Finally, we discuss DNA methylation profiling technologies and the most recent advances in single-cell methods, bisulfite-free approaches and ultra-long read sequencing techniques.

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Single molecule-level detection and long read-based phasing of epigenetic variations in bacterial methylomes

10.1101/007823 ◽

2014 ◽

Author(s):

John Beaulaurier ◽

Shijia Zhu ◽

Robert Sebra ◽

Xue-Song Zhang ◽

Chaggai Rosenbluh ◽

...

Keyword(s):

Dna Methylation ◽

Single Molecule ◽

Population Level ◽

Bacterial Strains ◽

Smrt Sequencing ◽

Bacterial Populations ◽

Single Molecule Level ◽

Genome Wide ◽

A Genome ◽

Long Read

Comprehensive genome-wide analyses of bacterial DNA methylation have not been possible until the recent advent of single molecule, real-time (SMRT) sequencing. This technology enables the direct detection of N6-methyladenine (6mA) and 4-methylcytosine (4mC) at single nucleotide resolution on a genome-wide scale. The distributions of these two major types of DNA methylation, along with 5-methylcytosine (5mC), comprise the bacterial methylome, some rare exceptions notwithstanding. SMRT sequencing has already revealed marked diversity in bacterial methylomes as well as the existence of heterogeneity of methylation in cells in single bacterial colonies, where such ‘epigenetic’ variation can enable bacterial populations to rapidly adapt to changing conditions. However, current methods for studying bacterial methylomes using SMRT sequencing mainly rely on population-level summaries that do not provide the single-cell resolution necessary for dissecting the epigenetic heterogeneity in bacterial populations. Here, we present a novel SMRT sequencing-based framework, consisting of two complementary methods, for single molecule-level detection of DNA methylation and assessment of methyltransferase activity through single molecule-level long read-based epigenetic phasing. Using seven bacterial strains and integrating data from SMRT and Illumina sequencing, we show that our method yields significantly improved resolution compared to existing population-level methods, and reveals several distinct types of epigenetic heterogeneity. Our approach enables new investigations of the complex architecture and dynamics of bacterial methylomes and provides a powerful new tool for the study of bacterial epigenetic control.

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Interaction between Microsatellite Instability (MSI) and Tumor DNA Methylation in the Pathogenesis of Colorectal Carcinoma

Cancers ◽

10.3390/cancers13194956 ◽

2021 ◽

Vol 13 (19) ◽

pp. 4956

Author(s):

Farzana Jasmine ◽

Zahidul Haq ◽

Mohammed Kamal ◽

Maruf Raza ◽

Gustavo da Silva ◽

...

Keyword(s):

Dna Methylation ◽

Microsatellite Instability ◽

Checkpoint Inhibitors ◽

Paired Comparison ◽

Paired Samples ◽

Anova Model ◽

Genome Wide ◽

A Genome ◽

Wide Scale ◽

Tumor Dna

In colorectal cancer (CRC), the role of microsatellite instability (MSI) is well known. In a genome-wide scale, for the first time, we explored whether differential methylation is associated with MSI. We analyzed 250 paired samples from 125 CRC patients (m = 72, f = 53) at different stages. Of them, 101 had left-sided CRC, 30 had MSI, 34 had somatic mutation in KRAS proto-oncogene (KRAS), and 6 had B-Raf proto-oncogene (BRAF) exon 15p.V600E mutation. MSI was more frequent in right-sided tumors (54% vs. 17%, p = 0.003). Among the microsatellite stable (MSS) CRC, a paired comparison revealed 1641 differentially methylated loci (DML) covering 686 genes at FDR 0.001 with delta beta ≥ 20%. Similar analysis in MSI revealed 6209 DML covering 2316 genes. ANOVA model including interaction (Tumor*MSI) revealed 23,322 loci, where the delta beta was different among MSI and MSS patients. Our study shows an association between MSI and tumor DNA methylation in the pathogenesis of CRC. Given the interaction seen in this study, it may be worth considering the MSI status while looking for methylation markers in CRC. The study also indicates an opportunity for potential use of certain immune checkpoint inhibitors (CTLA4 and HAVCR2 inhibitors) in CRC with MSI.

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Genome-wide DNA methylation profiling in anorexia nervosa discordant identical twins

Translational Psychiatry ◽

10.1038/s41398-021-01776-y ◽

2022 ◽

Vol 12 (1) ◽

Author(s):

C. Iranzo-Tatay ◽

D. Hervas-Marin ◽

L. M. Rojo-Bofill ◽

D. Garcia ◽

F. J. Vaz-Leal ◽

...

Keyword(s):

Dna Methylation ◽

Anorexia Nervosa ◽

Whole Blood ◽

Monozygotic Twin ◽

Psychological Traits ◽

Metabolic Traits ◽

Genome Wide ◽

A Genome ◽

Dna Methylation Profiling ◽

Methylation Profiling

AbstractUp until now, no study has looked specifically at epigenomic landscapes throughout twin samples, discordant for Anorexia nervosa (AN). Our goal was to find evidence to confirm the hypothesis that epigenetic variations play a key role in the aetiology of AN. In this study, we quantified genome-wide patterns of DNA methylation using the Infinium Human DNA Methylation EPIC BeadChip array (“850 K”) in DNA samples isolated from whole blood collected from a group of 7 monozygotic twin pairs discordant for AN. Results were then validated performing a genome-wide DNA methylation profiling using DNA extracted from whole blood of a group of non-family-related AN patients and a group of healthy controls. Our first analysis using the twin sample revealed 9 CpGs associated to a gene. The validation analysis showed two statistically significant CpGs with the rank regression method related to two genes associated to metabolic traits, PPP2R2C and CHST1. When doing beta regression, 6 of them showed statistically significant differences, including 3 CpGs associated to genes JAM3, UBAP2L and SYNJ2. Finally, the overall pattern of results shows genetic links to phenotypes which the literature has constantly related to AN, including metabolic and psychological traits. The genes PPP2R2C and CHST1 have both been linked to the metabolic traits type 2 diabetes through GWAS studies. The genes UBAP2L and SYNJ2 have been related to other psychiatric comorbidity.

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Genome-Wide Analysis of Cell-Free DNA Methylation Profiling with MeDIP-Seq Identified Potential Biomarkers for Colorectal Cancer

10.21203/rs.3.rs-643331/v1 ◽

2021 ◽

Author(s):

Xin Zhang ◽

Tao Li ◽

Qiang Niu ◽

Chang Jiang Qin ◽

Ming Zhang ◽

...

Keyword(s):

Colorectal Cancer ◽

Dna Methylation ◽

Cancer Patients ◽

Cell Free Dna ◽

Free Dna ◽

Genome Wide ◽

A Genome ◽

Colorectal Cancer Patients ◽

Methylation Profiling ◽

Potential Biomarkers

Abstract Background: To verify the feasibility of genome-wide plasma cell-free DNA(cfDNA) methylation profiling for early diagnosis of colorectal cancer.Methods: We performed a genome-wide cfDNA methylation profiling study of colorectal cancer patients by methylated DNA immunoprecipitation coupled with high throughput sequencing (MeDIP-seq).Results: Compared with the control group, 939 differentially methylated regions (DMRs) located in promoter regions were found in colorectal cancer patients, 16 of these DMRs were hypermethylated and the remaining 923 were hypomethylated. In addition, these hypermethylated genes, mainly including PRDM14, RALYL, ELMOD1, and TMEM132E, were validated and confirmed in colorectal cancer by using publicly available DNA methylation data.Conclusions: Our study indicates that MeDIP-seq can be used as an optimal approach for analyzing cfDNA methylomes, and the differentially methylated genes obtained by MeDIP-seq can be used as potential biomarkers for clinical application in patients with colorectal cancer.

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DNA Methylation at ATP11A cg11702988 Is a Biomarker of Lung Disease Severity in Cystic Fibrosis: A Longitudinal Study

Genes ◽

10.3390/genes12030441 ◽

2021 ◽

Vol 12 (3) ◽

pp. 441

Author(s):

Fanny Pineau ◽

Davide Caimmi ◽

Sylvie Taviaux ◽

Maurane Reveil ◽

Laura Brosseau ◽

...

Keyword(s):

Cystic Fibrosis ◽

Dna Methylation ◽

Clinical Trials ◽

Lung Disease ◽

Disease Severity ◽

Genome Wide ◽

A Genome ◽

Lung Disease Severity ◽

Epigenetic Biomarker

Cystic fibrosis (CF) is a chronic genetic disease that mainly affects the respiratory and gastrointestinal systems. No curative treatments are available, but the follow-up in specialized centers has greatly improved the patient life expectancy. Robust biomarkers are required to monitor the disease, guide treatments, stratify patients, and provide outcome measures in clinical trials. In the present study, we outline a strategy to select putative DNA methylation biomarkers of lung disease severity in cystic fibrosis patients. In the discovery step, we selected seven potential biomarkers using a genome-wide DNA methylation dataset that we generated in nasal epithelial samples from the MethylCF cohort. In the replication step, we assessed the same biomarkers using sputum cell samples from the MethylBiomark cohort. Of interest, DNA methylation at the cg11702988 site (ATP11A gene) positively correlated with lung function and BMI, and negatively correlated with lung disease severity, P. aeruginosa chronic infection, and the number of exacerbations. These results were replicated in prospective sputum samples collected at four time points within an 18-month period and longitudinally. To conclude, (i) we identified a DNA methylation biomarker that correlates with CF severity, (ii) we provided a method to easily assess this biomarker, and (iii) we carried out the first longitudinal analysis of DNA methylation in CF patients. This new epigenetic biomarker could be used to stratify CF patients in clinical trials.

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A Genome-Wide Integrative Association Study of DNA Methylation and Gene Expression Data and Later Life Cognitive Functioning in Monozygotic Twins

Frontiers in Neuroscience ◽

10.3389/fnins.2020.00233 ◽

2020 ◽

Vol 14 ◽

Cited By ~ 1

Author(s):

Mette Soerensen ◽

Dominika Marzena Hozakowska-Roszkowska ◽

Marianne Nygaard ◽

Martin J. Larsen ◽

Veit Schwämmle ◽

...

Keyword(s):

Gene Expression ◽

Dna Methylation ◽

Cognitive Functioning ◽

Association Study ◽

Gene Expression Data ◽

Monozygotic Twins ◽

Later Life ◽

Expression Data ◽

Genome Wide ◽

A Genome

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A genome-wide screen for differentially methylated long noncoding RNAs identified that lncAC007255.8 is regulated by promoter DNA methylation in Beas-2B cells malignantly transformed by NNK

Toxicology Letters ◽

10.1016/j.toxlet.2021.04.013 ◽

2021 ◽

Author(s):

Enzhao Chen ◽

Jiaxin Zhou ◽

Enwu Xu ◽

Cheng Zhang ◽

Jiayu Liu ◽

...

Keyword(s):

Dna Methylation ◽

Noncoding Rnas ◽

Long Noncoding Rnas ◽

Genome Wide ◽

A Genome ◽

Promoter Dna Methylation ◽

Promoter Dna

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Stable DNMT3L overexpression in SH-SY5Y neurons recreates a facet of the genome-wide Down syndrome DNA methylation signature

Epigenetics & Chromatin ◽

10.1186/s13072-021-00387-7 ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Benjamin I. Laufer ◽

J. Antonio Gomez ◽

Julia M. Jianu ◽

Janine M. LaSalle

Keyword(s):

Dna Methylation ◽

Down Syndrome ◽

Neuronal Differentiation ◽

Molecular Mechanisms ◽

Cpg Island ◽

Differential Methylation ◽

Chromosome 21 ◽

Pairwise Comparisons ◽

Genome Wide ◽

A Genome

Abstract Background Down syndrome (DS) is characterized by a genome-wide profile of differential DNA methylation that is skewed towards hypermethylation in most tissues, including brain, and includes pan-tissue differential methylation. The molecular mechanisms involve the overexpression of genes related to DNA methylation on chromosome 21. Here, we stably overexpressed the chromosome 21 gene DNA methyltransferase 3L (DNMT3L) in the human SH-SY5Y neuroblastoma cell line and assayed DNA methylation at over 26 million CpGs by whole genome bisulfite sequencing (WGBS) at three different developmental phases (undifferentiated, differentiating, and differentiated). Results DNMT3L overexpression resulted in global CpG and CpG island hypermethylation as well as thousands of differentially methylated regions (DMRs). The DNMT3L DMRs were skewed towards hypermethylation and mapped to genes involved in neurodevelopment, cellular signaling, and gene regulation. Consensus DNMT3L DMRs showed that cell lines clustered by genotype and then differentiation phase, demonstrating sets of common genes affected across neuronal differentiation. The hypermethylated DNMT3L DMRs from all pairwise comparisons were enriched for regions of bivalent chromatin marked by H3K4me3 as well as differentially methylated sites from previous DS studies of diverse tissues. In contrast, the hypomethylated DNMT3L DMRs from all pairwise comparisons displayed a tissue-specific profile enriched for regions of heterochromatin marked by H3K9me3 during embryonic development. Conclusions Taken together, these results support a mechanism whereby regions of bivalent chromatin that lose H3K4me3 during neuronal differentiation are targeted by excess DNMT3L and become hypermethylated. Overall, these findings demonstrate that DNMT3L overexpression during neurodevelopment recreates a facet of the genome-wide DS DNA methylation signature by targeting known genes and gene clusters that display pan-tissue differential methylation in DS.

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F-Box Genes in the Wheat Genome and Expression Profiling in Wheat at Different Developmental Stages

Genes ◽

10.3390/genes11101154 ◽

2020 ◽

Vol 11 (10) ◽

pp. 1154

Author(s):

Min Jeong Hong ◽

Jin-Baek Kim ◽

Yong Weon Seo ◽

Dae Yeon Kim

Keyword(s):

Developmental Stages ◽

Brachypodium Distachyon ◽

Triticum Aestivum L ◽

Wheat Genome ◽

Post Translational Modification ◽

Genome Wide ◽

A Genome ◽

High Sequence Homology ◽

Wide Scale

Genes of the F-box family play specific roles in protein degradation by post-translational modification in several biological processes, including flowering, the regulation of circadian rhythms, photomorphogenesis, seed development, leaf senescence, and hormone signaling. F-box genes have not been previously investigated on a genome-wide scale; however, the establishment of the wheat (Triticum aestivum L.) reference genome sequence enabled a genome-based examination of the F-box genes to be conducted in the present study. In total, 1796 F-box genes were detected in the wheat genome and classified into various subgroups based on their functional C-terminal domain. The F-box genes were distributed among 21 chromosomes and most showed high sequence homology with F-box genes located on the homoeologous chromosomes because of allohexaploidy in the wheat genome. Additionally, a synteny analysis of wheat F-box genes was conducted in rice and Brachypodium distachyon. Transcriptome analysis during various wheat developmental stages and expression analysis by quantitative real-time PCR revealed that some F-box genes were specifically expressed in the vegetative and/or seed developmental stages. A genome-based examination and classification of F-box genes provide an opportunity to elucidate the biological functions of F-box genes in wheat.

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