scholarly journals HPV Infection Leaves a DNA Methylation Signature in Oropharyngeal Cancer Affecting Both Coding Genes and Transposable Elements

Cancers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 3621
Author(s):  
Diego Camuzi ◽  
Luisa Aguirre Buexm ◽  
Simone de Queiroz Chaves Lourenço ◽  
Davide Degli Esposti ◽  
Cyrille Cuenin ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Transposable Elements ◽  
Hpv Infection ◽  
Cpg Methylation ◽  
Long Terminal Repeats ◽  
Regulate Gene Expression ◽  
Hpv Status ◽  
Line1 Methylation ◽  
Hpv Oncoproteins

HPV oncoproteins can modulate DNMT1 expression and activity, and previous studies have reported both gene-specific and global DNA methylation alterations according to HPV status in head and neck cancer. However, validation of these findings and a more detailed analysis of the transposable elements (TEs) are still missing. Here we performed pyrosequencing to evaluate a 5-CpG methylation signature and Line1 methylation in an oropharyngeal squamous cell carcinoma (OPSCC) cohort. We further evaluated the methylation levels of the TEs, their correlation with gene expression and their impact on overall survival (OS) using the TCGA cohort. In our dataset, the 5-CpG signature distinguished HPV-positive and HPV-negative OPSCC with 66.67% sensitivity and 84.33% specificity. Line1 methylation levels were higher in HPV-positive cases. In the TCGA cohort, Line1, Alu and long terminal repeats (LTRs) showed hypermethylation in a frequency of 60.5%, 58.9% and 92.3%, respectively. ZNF541 and CCNL1 higher expression was observed in HPV-positive OPSCC, correlated with lower methylation levels of promoter-associated Alu and LTR, respectively, and independently associated with better OS. Based on our findings, we may conclude that a 5-CpG methylation signature can discriminate OPSCC according to HPV status with high accuracy and TEs are differentially methylated and may regulate gene expression in HPV-positive OPSCC.

Biopsychosocial pathways to mental health and disease across the lifespan: The emerging role of epigenetics

2020 ◽  
pp. 190-206
Author(s):  
Charlotte A.M. Cecil
Keyword(s):  
Gene Expression ◽  
Mental Health ◽  
Dna Methylation ◽  
Mental Illness ◽  
Psychiatric Disorders ◽  
Regulate Gene Expression ◽  
Health And Disease ◽  
Regulate Gene ◽  
Epigenetic Processes

The biopsychosocial (BPS) model of psychiatry has had a major impact on our modern conceptualization of mental illness as a complex, multi-determined phenomenon. Yet, interdisciplinary BPS work remains the exception, rather than the rule in psychiatry. It has been suggested that this may stem in part from a failure of the BPS model to clearly delineate the mechanisms through which biological, psychological, and social factors co-act in the development of mental illness. This chapter discusses how epigenetic processes that regulate gene expression, such as DNA methylation, are fast emerging as a candidate mechanism for BPS interactions, with potentially widespread implications for the way that psychiatric disorders are understood, assessed, and, perhaps in future, even treated.

scholarly journals Impact of Transposable Elements on Methylation and Gene Expression across Natural Accessions of Brachypodium distachyon

2020 ◽  
Vol 12 (11) ◽  
pp. 1994-2001 ◽  
Author(s):  
Michele Wyler ◽  
Christoph Stritt ◽  
Jean-Claude Walser ◽  
Célia Baroux ◽  
Anne C Roulin
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Transposable Elements ◽  
Brachypodium Distachyon ◽  
Large Fraction ◽  
Expression Patterns ◽  
Specific Gene ◽  
Differential Gene ◽  
The Relationship ◽  
Silent State

Abstract Transposable elements (TEs) constitute a large fraction of plant genomes and are mostly present in a transcriptionally silent state through repressive epigenetic modifications, such as DNA methylation. TE silencing is believed to influence the regulation of adjacent genes, possibly as DNA methylation spreads away from the TE. Whether this is a general principle or a context-dependent phenomenon is still under debate, pressing for studying the relationship between TEs, DNA methylation, and nearby gene expression in additional plant species. Here, we used the grass Brachypodium distachyon as a model and produced DNA methylation and transcriptome profiles for 11 natural accessions. In contrast to what is observed in Arabidopsis thaliana, we found that TEs have a limited impact on methylation spreading and that only few TE families are associated with a low expression of their adjacent genes. Interestingly, we found that a subset of TE insertion polymorphisms is associated with differential gene expression across accessions. Thus, although not having a global impact on gene expression, distinct TE insertions may contribute to specific gene expression patterns in B. distachyon.

scholarly journals Stress-induced gene expression and behavior are controlled by DNA methylation and methyl donor availability in the dentate gyrus

2016 ◽  
Vol 113 (17) ◽  
pp. 4830-4835 ◽  
Author(s):  
Emily A. Saunderson ◽  
Helen Spiers ◽  
Karen R. Mifsud ◽  
Maria Gutierrez-Mecinas ◽  
Alexandra F. Trollope ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Dentate Gyrus ◽  
Crucial Role ◽  
Histone H3 ◽  
Behavioral Responses ◽  
Cpg Methylation ◽  
Granule Neurons ◽  
Methyl Donor ◽  
And Behavior

Stressful events evoke long-term changes in behavioral responses; however, the underlying mechanisms in the brain are not well understood. Previous work has shown that epigenetic changes and immediate-early gene (IEG) induction in stress-activated dentate gyrus (DG) granule neurons play a crucial role in these behavioral responses. Here, we show that an acute stressful challenge [i.e., forced swimming (FS)] results in DNA demethylation at specific CpG (5′-cytosine–phosphate–guanine-3′) sites close to the c-Fos (FBJ murine osteosarcoma viral oncogene homolog) transcriptional start site and within the gene promoter region of Egr-1 (early growth response protein 1) specifically in the DG. Administration of the (endogenous) methyl donor S-adenosyl methionine (SAM) did not affect CpG methylation and IEG gene expression at baseline. However, administration of SAM before the FS challenge resulted in an enhanced CpG methylation at the IEG loci and suppression of IEG induction specifically in the DG and an impaired behavioral immobility response 24 h later. The stressor also specifically increased the expression of the de novo DNA methyltransferase Dnmt3a [DNA (cytosine-5-)-methyltransferase 3 alpha] in this hippocampus region. Moreover, stress resulted in an increased association of Dnmt3a enzyme with the affected CpG loci within the IEG genes. No effects of SAM were observed on stress-evoked histone modifications, including H3S10p-K14ac (histone H3, phosphorylated serine 10 and acetylated lysine-14), H3K4me3 (histone H3, trimethylated lysine-4), H3K9me3 (histone H3, trimethylated lysine-9), and H3K27me3 (histone H3, trimethylated lysine-27). We conclude that the DNA methylation status of IEGs plays a crucial role in FS-induced IEG induction in DG granule neurons and associated behavioral responses. In addition, the concentration of available methyl donor, possibly in conjunction with Dnmt3a, is critical for the responsiveness of dentate neurons to environmental stimuli in terms of gene expression and behavior.

scholarly journals Impact of transposable elements on methylation and gene expression across natural accessions of Brachypodium distachyon

2020 ◽  
Author(s):  
Michele Wyler ◽  
Christoph Stritt ◽  
Jean-Claude Walser ◽  
Célia Baroux ◽  
Anne C. Roulin
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Transposable Elements ◽  
Plant Species ◽  
Brachypodium Distachyon ◽  
Expression Patterns ◽  
Small Subset ◽  
Molecular Evidence ◽  
Specific Gene ◽  
Plant Genomes

AbstractTransposable elements (TEs) constitute a large fraction of plant genomes and are mostly present in a transcriptionally silent state through repressive epigenetic modifications such as DNA methylation. TE silencing is believed to influence the regulation of adjacent genes, possibly as DNA methylation spreads away from the TE. Whether this is a general principle or a context-dependent phenomenon is still under debate, pressing for studying the relationship between TEs, DNA methylation and nearby gene expression in additional plant species. Here we used the grass Brachypodium distachyon as a model and produced DNA methylation and transcriptome profiles for eleven natural accessions. In contrast to what is observed in Arabidopsis thaliana, we found that TEs have a limited impact on methylation spreading and that only few TE families are associated to a low expression of their adjacent genes. Interestingly, we found that a subset of TE insertion polymorphisms is associated with differential gene expression across accessions. Thus, although not having a global impact on gene expression, distinct TE insertions may contribute to specific gene expression patterns in B. distachyon.Significance statementTransposable elements (TEs) are a major component of plant genomes and a source of genetic and epigenetic innovations underlying adaptation to changing environmental conditions. Yet molecular evidence linking TE silencing and nearby gene expression are lacking for many plant species. We show that in the model grass Brachypodium DNA methylation spreads over very short distances around TEs, with an influence on gene expression for a small subset of TE families.

Analysis of DNA Methylation and Transcription During Granulopoiesis Reveals Timed Methylation Changes in Low CpG Areas That Correlate with Changed Transcriptional Activity.

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 2334-2334
Author(s):  
Rönnerblad Michelle ◽  
Olofsson Tor ◽  
Iyadh Douagi ◽  
Sören Lehmann ◽  
Karl Ekwall ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Conflicts Of Interest ◽  
Cell Types ◽  
Cpg Methylation ◽  
Epigenetic Mechanism ◽  
450K Array ◽  
Chi Square ◽  
Heterochromatin Formation ◽  
Chi Square Test

Abstract Abstract 2334 Accumulating evidence demonstrates that epigenetic changes, including DNA methylation play a central role in differentiation, providing cellular memory and stabilizing lineage choice in hematopoiesis1–3. DNA methylation is an important epigenetic mechanism involved in transcriptional regulation, heterochromatin formation and the normal development of many organisms. In this study we investigated the DNA methylome and transcriptome of human cells in four separate differentiation stages in granulopoiesis, ranging from the multipotent Common Myeloid progenitor (CMP) to terminally differentiated bone marrow neutrophils (PMN). To this end we employed HumanMethylation 450 BeadChip (450K array) from Illumina with extensive genomic coverage and mRNA expression arrays (Illumina). Temporally distinct methylation changes during granulopoiesis Differential methylation between two cell stages was defined as an average difference in β value of at least 0.17 (p ≤ 0.05). We detected 12132 DMSs during granulopoiesis. Of these the majority showed decreased methylation during granulopoeisis (10771 CpGs) and a smaller set gained methylation (1658 CpGs). Strikingly, increases in methylation predominantly occur between CMP and GMP, the two least mature cell types. Some CpGs also show increased methylation in the GMP-PMC transition, while very few CpG sites increase at the final stage of differentiation from PMC to PMN. Although reduction of methylation occurs at all stages of granulopoiesis, the greatest change is between GMP and PMC. It is striking that the DNA methylation patterns preferentially change at points of lineage restriction, and that the greatest change occurs upon loss of oligopotency between GMP and PMC. DMSs within CGIs were greatly underrepresented (p<0.001 with chi-square test), while DMSs were overrepresented in shelves (p<0.001) and open sea (p<0.001). Thus, methylation appears to be more dynamic outside of CGIs during granulocytic development. For all regions the variation within enhancers was greater than outside of enhancers indicating greater methylation changes in enhancers compared to non-enhancers. In addition, CpGs in enhancer regions are significantly enriched in the list of DMSs (p<0.001, chi-square test) further supporting the observation that enhancer regions display dynamic DNA methylation changes during granulopoiesis. Changes in gene expression correlate with DNA methylation changes There was a significant overlap between genes showing decreased methylation and genes with increased expression as well as for the reverse comparison between genes with increased methylation and decreased expression. Thus, support a general anticorrelation between DNA methylation and gene expression. Azurophilic granule proteins showed increased expression peaking in PMC and a rapid decrease toward PMN. CpG methylation levels for those genes decreased concomitantly with the peak in expression. We report cell population specific changes of DNA methylation levels. The main reduction of CpG methylation coincides with the loss of oligopotency at the transition from GMP-PMC. This suggests a role of DNA methylation in regulating cell plasticity and lineage choice. Disclosures: No relevant conflicts of interest to declare.

scholarly journals DNA methylation subpatterns at distinct regulatory regions in human early embryos

Open Biology ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 180131 ◽  
Author(s):  
Rongsong Luo ◽  
Chunling Bai ◽  
Lei Yang ◽  
Zhong Zheng ◽  
Guanghua Su ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Correlation Analysis ◽  
Promoter Region ◽  
Promoter Regions ◽  
Regulate Gene Expression ◽  
Early Embryos ◽  
Candidate Promoter ◽  
Single Base Resolution ◽  
Genomic Regions

DNA methylation has been investigated for many years, but recent technologies have allowed for single-cell- and single-base-resolution DNA methylation datasets and more accurate assessment of DNA methylation dynamics at the key genomic regions that regulate gene expression in human early embryonic development. In this study, the region from upstream 20 kb to downstream 20 kb of RefSeq gene was selected and divided into 12 distinct regions (up20, up10, up5, up2, 5'UTR, exon, intron, 3'UTR, down2, down5, down10 and down20). The candidate promoter region (TSS ± 2 kb) was further divided into 20 consecutive subregions, which were termed ‘bins’. The DNA methylation dynamics of these regions were systematically analysed along with their effects on gene expression in human early embryos. The dynamic DNA methylation subpatterns at the distinct genomic regions with a focus on promoter regions were mapped. For the 12 distinct genomic regions, up2 and 5'UTR had the lowest DNA methylation levels, and their methylation dynamics were different with other regions. The region 3'UTR had the highest DNA methylation levels, and the correlation analysis with gene expression proved that it was a feature of transcribed genes. For the 20 bins in promoter region, the CpG densities showed a normal distribution pattern, and the trend of the methylated CpG counts was inverse with the DNA methylation levels, especially for the bin 1 (downstream 200 bp of the TSS). Through the correlation analysis between DNA methylation and gene expression, the current study finally revealed that the region bin −4 to 6 (800 bp upstream to 1200 bp downstream of the TSS) was the best candidate for the promoter region in human early embryos, and bin 1 was the putative key regulator of gene activity. This study provided a global and high-resolution view of DNA methylation subpatterns at the distinct genomic regions in human early embryos.

Reproductive technologies for the future: a role for epigenetics

2013 ◽  
Vol 53 (9) ◽  
pp. 954 ◽  
Author(s):  
Caroline G. Walker ◽  
Murray D. Mitchell
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Early Pregnancy ◽  
Reproductive Technologies ◽  
Vitamin Supplementation ◽  
Regulate Gene Expression ◽  
Positive Effects ◽  
One Carbon Metabolism ◽  
Aberrant Dna Methylation ◽  
B Vitamin

Epigenetic mechanisms, such as DNA methylation, regulate gene expression and, subsequently, phenotype, without changing the underlying DNA sequence. It is well established that the environment and nutrition can regulate methylation and, therefore, modify phenotype. In this review, regulation of DNA methylation and in particular, the influence of B-vitamin on one-carbon metabolism is outlined, and how deficiency or supplementation with B-vitamins, such as folate, can influence disease. Evidence is provided for the roles of B-vitamin in regulating reproduction and how deficiency of B-vitamin may be impacting dairy cattle fertility. Results from our laboratory provide evidence for an association between DNA methylation and gene expression in the endometrium during early pregnancy. It is, therefore, hypothesised that DNA methylation may regulate the uterine response to the embryo during early pregnancy and that aberrant DNA methylation during this time may jeopardise pregnancy success. Further research is required to establish if B-vitamin supplementation can improve reproductive success and if this effect is via changes to DNA methylation and gene expression in the endometrium, or via positive effects on oocyte and embryo development.

scholarly journals Human Papillomavirus Drives Tumor Development Throughout the Head and Neck: Improved Prognosis Is Associated With an Immune Response Largely Restricted to the Oropharynx

2016 ◽  
Vol 34 (34) ◽  
pp. 4132-4141 ◽  
Author(s):  
Ankur Chakravarthy ◽  
Stephen Henderson ◽  
Stephen M. Thirdborough ◽  
Christian H. Ottensmeier ◽  
Xiaoping Su ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Human Papillomavirus ◽  
Head And Neck ◽  
Squamous Cell ◽  
Survival Data ◽  
Squamous Cell Carcinomas ◽  
Causal Role ◽  
Anatomic Site ◽  
Hpv Status

Purpose In squamous cell carcinomas of the head and neck (HNSCC), the increasing incidence of oropharyngeal squamous cell carcinomas (OPSCCs) is attributable to human papillomavirus (HPV) infection. Despite commonly presenting at late stage, HPV-driven OPSCCs are associated with improved prognosis compared with HPV-negative disease. HPV DNA is also detectable in nonoropharyngeal (non-OPSCC), but its pathogenic role and clinical significance are unclear. The objectives of this study were to determine whether HPV plays a causal role in non-OPSCC and to investigate whether HPV confers a survival benefit in these tumors. Methods Meta-analysis was used to build a cross-tissue gene-expression signature for HPV-driven cancer. Classifiers trained by machine-learning approaches were used to predict the HPV status of 520 HNSCCs profiled by The Cancer Genome Atlas project. DNA methylation data were similarly used to classify 464 HNSCCs and these analyses were integrated with genomic, histopathology, and survival data to permit a comprehensive comparison of HPV transcript-positive OPSCC and non-OPSCC. Results HPV-driven tumors accounted for 4.1% of non-OPSCCs. Regardless of anatomic site, HPV+ HNSCCs shared highly similar gene expression and DNA methylation profiles; nonkeratinizing, basaloid histopathological features; and lack of TP53 or CDKN2A alterations. Improved overall survival, however, was largely restricted to HPV-driven OPSCCs, which were associated with increased levels of tumor-infiltrating lymphocytes compared with HPV-driven non-OPSCCs. Conclusion Our analysis identified a causal role for HPV in transcript-positive non-OPSCCs throughout the head and neck. Notably, however, HPV-driven non-OPSCCs display a distinct immune microenvironment and clinical behavior compared with HPV-driven OPSCCs.

scholarly journals The plant mobile domain proteins MAIN and MAIL1 interact with the phosphatase PP7L to regulate gene expression and silence transposable elements in Arabidopsis thaliana

2019 ◽  
Author(s):  
Melody Nicolau ◽  
Nathalie Picault ◽  
Julie Descombin ◽  
Yasaman Jami-Alahmadi ◽  
Suhua Feng ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Arabidopsis Thaliana ◽  
Transposable Elements ◽  
Genome Stability ◽  
Phylogenetic Analyses ◽  
Dna Repeats ◽  
Functional Protein ◽  
Developmental Processes ◽  
Phosphoprotein Phosphatase

ABSTRACTTransposable elements (TEs) are DNA repeats that must remain silenced to ensure cell integrity. Several epigenetic pathways including DNA methylation and histone modifications are involved in the silencing of TEs, and in the regulation of gene expression. In Arabidopsis thaliana, the TE-derived plant mobile domain (PMD) proteins have been involved in TE silencing, genome stability, and control of developmental processes. Using a forward genetic screen, we found that the PMD protein MAINTENANCE OF MERISTEMS (MAIN) acts synergistically and redundantly with DNA methylation to silence TEs. We found that MAIN and its close homolog MAIN-LIKE 1 (MAIL1) interact together, as well as with the phosphoprotein phosphatase (PPP) PP7-like (PP7L). Remarkably, main, mail1, pp7l single and mail1 pp7l double mutants display similar developmental phenotypes, and share common subsets of upregulated TEs and misregulated genes. Finally, phylogenetic analyses of PMD and PP7-type PPP domains among the Eudicot lineage suggest neo-association processes between the two protein domains to potentially generate new protein function. We propose that, through this interaction, the PMD and PPP domains may constitute a functional protein module required for the proper expression of a common set of genes, and for silencing of TEs.AUTHOR SUMMARYThe plant mobile domain (PMD) is a protein domain of unknown function that is widely spread in the angiosperm plants. Although most PMDs are associated with repeated DNA sequences called transposable elements (TEs), plants have domesticated the PMD to produce genic versions that play important roles within the cell. In Arabidopsis thaliana, MAINTENANCE OF MERISTEMS (MAIN) and MAIN-LIKE 1 (MAIL1) are genic PMDs that are involved in genome stability, developmental processes, and silencing of TEs. The mechanisms involving MAIN and MAIL1 in these cellular processes remain elusive. Here, we show that MAIN, MAIL1 and the phosphoprotein phosphatase (PPP) named PP7-like (PP7L) interact to form a protein complex that is required for the proper expression of genes, and the silencing of TEs. Phylogenetic analyses revealed that PMD and PP7-type PPP domains are evolutionary connected, and several plant species express proteins carrying both PMD and PPP domains. We propose that interaction of PMD and PPP domains would create a functional protein module involved in mechanisms regulating gene expression and repressing TEs.

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