An integrated analysis of genome-wide DNA methylation and genetic variants underlying etoposide-induced cytotoxicity in European and African populations

2014 ◽  
pp. 928-938 ◽  
Author(s):  
Ruowang Li ◽  
Dokyoon Kim ◽  
Scott M. Dudek ◽  
Marylyn D. Ritchie
Keyword(s):  
Dna Methylation ◽  
Genetic Variants ◽  
Integrated Analysis ◽  
Genome Wide ◽  
African Populations

scholarly journals Epigenome-wide association study of seizures in childhood and adolescence

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Doretta Caramaschi ◽  
Charlie Hatcher ◽  
Rosa H. Mulder ◽  
Janine F. Felix ◽  
Charlotte A. M. Cecil ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Genetic Variants ◽  
Mendelian Randomization ◽  
Independent Study ◽  
Childhood And Adolescence ◽  
Parents And Children ◽  
Genome Wide ◽  
Common Genetic Variants ◽  
The Brain ◽  
Avon Longitudinal Study

AbstractThe occurrence of seizures in childhood is often associated with neurodevelopmental impairments and school underachievement. Common genetic variants associated with epilepsy have been identified and epigenetic mechanisms have also been suggested to play a role. In this study, we analyzed the association of genome-wide blood DNA methylation with the occurrence of seizures in ~ 800 children from the Avon Longitudinal Study of Parents and Children, UK, at birth (cord blood), during childhood, and adolescence (peripheral blood). We also analyzed the association between the lifetime occurrence of any seizures before age 13 with blood DNA methylation levels. We sought replication of the findings in the Generation R Study and explored causality using Mendelian randomization, i.e., using genetic variants as proxies. The results showed five CpG sites which were associated cross-sectionally with seizures either in childhood or adolescence (1–5% absolute methylation difference at pFDR < 0.05), although the evidence of replication in an independent study was weak. One of these sites was located in the BDNF gene, which is highly expressed in the brain, and showed high correspondence with brain methylation levels. The Mendelian randomization analyses suggested that seizures might be causal for changes in methylation rather than vice-versa. In conclusion, we show a suggestive link between seizures and blood DNA methylation while at the same time exploring the limitations of conducting such study.

scholarly journals A Genome-Wide mQTL Analysis in Human Adipose Tissue Identifies Genetic Variants Associated with DNA Methylation, Gene Expression and Metabolic Traits

PLoS ONE ◽  
2016 ◽  
Vol 11 (6) ◽  
pp. e0157776 ◽  
Author(s):  
Petr Volkov ◽  
Anders H. Olsson ◽  
Linn Gillberg ◽  
Sine W. Jørgensen ◽  
Charlotte Brøns ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Adipose Tissue ◽  
Genetic Variants ◽  
Human Adipose Tissue ◽  
Metabolic Traits ◽  
Genome Wide ◽  
A Genome

scholarly journals Epigenome-wide association study of seizures in childhood and adolescence

2019 ◽  
Author(s):  
Doretta Caramaschi ◽  
Charlie Hatcher ◽  
Rosa H. Mulder ◽  
Janine F. Felix ◽  
Charlotte A. M. Cecil ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Genetic Variants ◽  
Cognitive Skills ◽  
Mendelian Randomization ◽  
Independent Study ◽  
Childhood And Adolescence ◽  
Parents And Children ◽  
Genome Wide ◽  
Common Genetic Variants ◽  
The Brain

ABSTRACTThe occurrence of seizures in childhood is often associated with neurodevelopmental impairments and school underachievement. Common genetic variants associated with epilepsy have been identified and epigenetic mechanisms have also been suggested to play a role. In this study we analysed the association of genome-wide blood DNA methylation with the occurrence of seizures in ∼800 children from the Avon Longitudinal Study of Parents and Children, UK, at birth (cord blood), during childhood and adolescence (peripheral blood). We also analysed the association between the lifetime occurrence of any seizures before age 13 with blood DNA methylation levels. We sought replication of the findings in the Generation R Study and explored causality using Mendelian randomization, i.e. using genetic variants as proxies. The results showed five CpG sites which were associated cross-sectionally with seizures either in childhood or adolescence (1-5% absolute methylation difference at pFDR<0.05), although the evidence of replication in an independent study was weak. One of these sites was located in the BDNF gene, which is highly expressed in the brain, and showed high correspondence with brain methylation levels. The Mendelian randomization analyses suggested that seizures might be causal for changes in methylation rather than vice-versa. In addition, seizure-associated methylation changes could affect other outcomes such as growth, cognitive skills and educational attainment. In conclusion, we present a link between seizures and DNA methylation which suggests that DNA methylation changes might mediate some of the effects of seizures on growth and neurodevelopment.

scholarly journals Integrative analysis of genome-wide DNA methylation and single-nucleotide polymorphism identified ACSM5 as a suppressor of lumbar ligamentum flavum hypertrophy

2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Yanlin Cao ◽  
Yenan Zhan ◽  
Sujun Qiu ◽  
Zhong Chen ◽  
Kaiqin Gong ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Single Nucleotide Polymorphism ◽  
Ligamentum Flavum ◽  
Global Analysis ◽  
Integrated Analysis ◽  
Polymorphism Analysis ◽  
Nucleotide Polymorphism ◽  
Single Nucleotide ◽  
Genome Wide ◽  
A Genome

Abstract Background Hypertrophy of ligamentum flavum (HLF) is a common lumbar degeneration disease (LDD) with typical symptoms of low back pain and limb numbness owing to an abnormal pressure on spinal nerves. Previous studies revealed HLF might be caused by fibrosis, inflammatory, and other bio-pathways. However, a global analysis of HLF is needed severely. Methods A genome-wide DNA methylation and single-nucleotide polymorphism analysis were performed from five LDD patients with HLF and five LDD patients without HLF. Comprehensive integrated analysis was performed using bioinformatics analysis and the validated experiments including Sanger sequencing, methylation-specific PCR, qPCR and ROC analysis. Furthermore, the function of novel genes in ligamentum flavum cells (LFCs) was detected to explore the molecular mechanism in HLF through knock down experiment, overexpression experiment, CCK8 assay, apoptosis assay, and so on. Results We identified 69 SNP genes and 735 661 differentially methylated sites that were enriched in extracellular matrix, inflammatory, and cell proliferation. A comprehensive analysis demonstrated key genes in regulating the development of HLF including ACSM5. Furthermore, the hypermethylation of ACSM5 that was mediated by DNMT1 led to downregulation of ACSM5 expression, promoted the proliferation and fibrosis, and inhibited the apoptosis of LFCs. Conclusion This study revealed that DNMT1/ACSM5 signaling could enhance HLF properties in vitro as a potential therapeutic strategy for HLF.

Genome-wide DNA methylation and expression patterns of microRNAs in relation to breast cancer subtypes among American women of African and European ancestry

2020 ◽  
Author(s):  
Zhihong Gong ◽  
Jianhong Chen ◽  
Jie Wang ◽  
Song Liu ◽  
Christine B. Ambrosone ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Dna Methylation ◽  
Racial Differences ◽  
Mirna Expression ◽  
Expression Patterns ◽  
European Ancestry ◽  
Integrated Analysis ◽  
American Women ◽  
Mirna Genes ◽  
Genome Wide

Abstract Background: Aggressive high-grade, estrogen receptor negative (ER-) breast cancer is more common among American women of African ancestry (AA) than those of European ancestry (EA). The reasons remain largely unknown. Epigenetic mechanisms, particularly DNA methylation and altered microRNA (miRNA) expression, may contribute to racial differences in breast cancer. However, few studies have specifically characterized genome-wide DNA methylation-based modifications at the miRNA level in relation to ER+ and ER- breast cancer, and their functional role in the regulation of miRNA expression, especially among high risk AA women. Methods: In this study, genome-wide DNA methylation and miRNA expression profiling was performed using the Illumina Infinium HumanMethylation450 Bead Chip platform and miRNA sequencing (miRNA-seq) in breast tumors from both AA and EA women. Results: The genome-wide methylation screen identified a total of 7,191 unique CpGs mapped to 1,292 miRNA genes, which correspond to 2,035 unique mature miRNAs. Cluster analysis of these miRNA-associated methylation loci showed a clear pattern of ER-subtype differences. We identified differentially methylated loci (DMLs: (|delta β|)>0.10, FDR<0.05) between ER- and ER+ tumor subtypes, including 290 DMLs shared in both races, 317 and 136 were specific to AA and EA women, respectively. Integrated analysis of DNA methylation and corresponding miRNA expression identified certain DMLs whose methylation levels were significantly correlated with the expression of relevant miRNAs, such as multiple CpGs within miR-190b and miR-135b highly negatively correlated with their expression. Further target prediction and pathway analysis showed that these DNA methylation-dysregulated miRNAs are involved in multiple cancer-related pathways, including cell cycle G1-S growth factor, cytoskeleton remodeling, angiogenesis, EMT, and others such as signal transduction TGF-β, Wnt, NOTCH, and ESR1-mediated signaling pathways. Conclusions: Our results suggest that DNA methylation changes within miRNA genes are associated with altered miRNA expression, which may contribute to the network of subtype- and race-related tumor biological differences in breast cancer. These findings shed light on the epigenetic regulation of miRNA expression and provide insights into the relations of clinical-relevant miRNAs to their target genes and to serve as potential preventative and therapeutic targets.

scholarly journals A pooling-based approach to mapping genetic variants associated with DNA methylation

2015 ◽  
Author(s):  
Irene Miriam Kaplow ◽  
Julia L MacIsaac ◽  
Sarah M Mah ◽  
Lisa M McEwen ◽  
Michael S Kobor ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Genetic Variants ◽  
Statistical Power ◽  
Epigenetic Modification ◽  
Chromatin Accessibility ◽  
Ctcf Binding ◽  
Sequencing Data ◽  
Individual Level ◽  
Novel Approach ◽  
Genome Wide

DNA methylation is an epigenetic modification that plays a key role in gene regulation. Previous studies have investigated its genetic basis by mapping genetic variants that are associated with DNA methylation at specific sites, but these have been limited to microarrays that cover less than 2% of the genome and cannot account for allele-specific methylation (ASM). Other studies have performed whole-genome bisulfite sequencing on a few individuals, but these lack statistical power to identify variants associated with DNA methylation. We present a novel approach in which bisulfite-treated DNA from many individuals is sequenced together in a single pool, resulting in a truly genome-wide map of DNA methylation. Compared to methods that do not account for ASM, our approach increases statistical power to detect associations while sharply reducing cost, effort, and experimental variability. As a proof of concept, we generated deep sequencing data from a pool of 60 human cell lines; we evaluated almost twice as many CpGs as the largest microarray studies and identified over 2,000 genetic variants associated with DNA methylation. We found that these variants are highly enriched for associations with chromatin accessibility and CTCF binding but are less likely to be associated with traits indirectly linked to DNA, such as gene expression and disease phenotypes. In summary, our approach allows genome-wide mapping of genetic variants associated with DNA methylation in any tissue of any species, without the need for individual-level genotype or methylation data.

scholarly journals Integrated analysis of the methylome and transcriptome of chickens with fatty liver hemorrhagic syndrome

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Xiaodong Tan ◽  
Ranran Liu ◽  
Yonghong Zhang ◽  
Xicai Wang ◽  
Jie Wang ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Fatty Acid ◽  
Fatty Liver ◽  
Negative Relationship ◽  
Integrated Analysis ◽  
Pathway Enrichment Analysis ◽  
Gene Body ◽  
Genome Wide ◽  
A Genome ◽  
Differentially Methylated Genes

Abstract Background DNA methylation, a biochemical modification of cytosine, has an important role in lipid metabolism. Fatty liver hemorrhagic syndrome (FLHS) is a serious disease and is tightly linked to lipid homeostasis. Herein, we compared the methylome and transcriptome of chickens with and without FLHS. Results We found genome-wide dysregulated DNA methylation pattern in which regions up- and down-stream of gene body were hypo-methylated in chickens with FLHS. A total of 4155 differentially methylated genes and 1389 differentially expressed genes were identified. Genes were focused when a negative relationship between mRNA expression and DNA methylation in promoter and gene body were detected. Based on pathway enrichment analysis, we found expression of genes related to lipogenesis and oxygenolysis (e.g., PPAR signaling pathway, fatty acid biosynthesis, and fatty acid elongation) to be up-regulated with associated down-regulated DNA methylation. In contrast, genes related to cellular junction and communication pathways (e.g., vascular smooth muscle contraction, phosphatidylinositol signaling system, and gap junction) were inhibited and with associated up-regulation of DNA methylation. Conclusions In the current study, we provide a genome-wide scale landscape of DNA methylation and gene expression. The hepatic hypo-methylation feature has been identified with FLHS chickens. By integrated analysis, the results strongly suggest that increased lipid accumulation and hepatocyte rupture are central pathways that are regulated by DNA methylation in chickens with FLHS.

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