scholarly journals PCR-Based Methods for Detecting Single-Locus DNA Methylation Biomarkers in Cancer Diagnostics, Prognostics, and Response to Treatment

2009 ◽  
Vol 55 (8) ◽  
pp. 1471-1483 ◽  
Author(s):  
Lasse Sommer Kristensen ◽  
Lise Lotte Hansen
Keyword(s):  
Dna Methylation ◽  
Epigenetic Modification ◽  
Cancer Diagnostics ◽  
Response To Therapy ◽  
Response To Treatment ◽  
Diagnostic Tools ◽  
Promoter Regions ◽  
Advantages And Disadvantages ◽  
Specific Pcr ◽  
Methylation Patterns

Abstract Background: DNA methylation is a highly characterized epigenetic modification of the human genome that is implicated in cancer. The altered DNA methylation patterns found in cancer cells include not only global hypomethylation but also discrete hypermethylation of specific genes. In particular, numerous tumor suppressor genes undergo epigenetic silencing because of hypermethylated promoter regions. Some of these genes are considered promising DNA methylation biomarkers for early cancer diagnostics, and some have been shown to be valuable for predicting prognosis or the response to therapy. Content: PCR-based methods that use sodium bisulfite–treated DNA as a template are generally accepted as the most analytically sensitive and specific techniques for analyzing DNA methylation at single loci. A number of new methods, such as methylation-specific fluorescent amplicon generation (MS-FLAG), methylation-sensitive high-resolution melting (MS-HRM), and sensitive melting analysis after real-time methylation-specific PCR (SMART-MSP), now complement the traditional PCR-based methods and promise to be valuable diagnostic tools. In particular, the HRM technique shows great potential as a diagnostic tool because of its closed-tube format and cost-effectiveness. Summary: Numerous traditional and new PCR-based methods have been developed for detecting DNA methylation at single loci. All have characteristic advantages and disadvantages, particularly with regard to use in clinical settings.

A role for poly(ADP-ribosyl)ation in DNA methylation

2003 ◽  
Vol 81 (3) ◽  
pp. 197-208 ◽  
Author(s):  
Giuseppe Zardo ◽  
Anna Reale ◽  
Giovanna De Matteis ◽  
Serena Buontempo ◽  
Paola Caiafa
Keyword(s):  
Dna Methylation ◽  
Gene Silencing ◽  
Control Mechanism ◽  
Epigenetic Modification ◽  
Housekeeping Genes ◽  
Promoter Regions ◽  
Epigenetic Events ◽  
Aberrant Dna Methylation ◽  
Methylation Patterns ◽  
Histone Methylation And Acetylation

The aberrant DNA methylation of promoter regions of housekeeping genes leads to gene silencing. Additional epigenetic events, such as histone methylation and acetylation, also play a very important role in the definitive repression of gene expression by DNA methylation. If the aberrant DNA methylation of promoter regions is the starting or the secondary event leading to the gene silencing is still debated. Mechanisms controlling DNA methylation patterns do exist although they have not been ultimately proven. Our data suggest that poly(ADP-ribosyl)ation might be part of this control mechanism. Thus an additional epigenetic modification seems to be involved in maintaining tissue and cell-type methylation patterns that when formed during embryo development, have to be rigorously conserved in adult organisms.Key words: DNA methylation, chromatin, poly(ADP-ribosyl)ation.

scholarly journals DNA Methylation Events as Markers for Diagnosis and Management of Acute Myeloid Leukemia and Myelodysplastic Syndrome

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Geórgia Muccillo Dexheimer ◽  
Jayse Alves ◽  
Laura Reckziegel ◽  
Gabrielle Lazzaretti ◽  
Ana Lucia Abujamra
Keyword(s):  
Dna Methylation ◽  
Acute Myeloid Leukemia ◽  
Myelodysplastic Syndrome ◽  
Myeloid Leukemia ◽  
Epigenetic Modification ◽  
Dynamic Change ◽  
Cellular Transformation ◽  
Response To Therapy ◽  
Response To Treatment ◽  
Acute Myeloid

During the onset and progression of hematological malignancies, many changes occur in cellular epigenome, such as hypo- or hypermethylation of CpG islands in promoter regions. DNA methylation is an epigenetic modification that regulates gene expression and is a key event for tumorigenesis. The continuous search for biomarkers that signal early disease, indicate prognosis, and act as therapeutic targets has led to studies investigating the role of DNA in cancer onset and progression. This review focuses on DNA methylation changes as potential biomarkers for diagnosis, prognosis, response to treatment, and early toxicity in acute myeloid leukemia and myelodysplastic syndrome. Here, we report that distinct changes in DNA methylation may alter gene function and drive malignant cellular transformation during several stages of leukemogenesis. Most of these modifications occur at an early stage of disease and may predict myeloid/lymphoid transformation or response to therapy, which justifies its use as a biomarker for disease onset and progression. Methylation patterns, or its dynamic change during treatment, may also be used as markers for patient stratification, disease prognosis, and response to treatment. Further investigations of methylation modifications as therapeutic biomarkers, which may correlate with therapeutic response and/or predict treatment toxicity, are still warranted.

Examination of the dynamics of global DNA methylation pattern establishment during spermatogenesiss

2007 ◽  
Vol 30 (4) ◽  
pp. 90
Author(s):  
Kirsten Niles ◽  
Sophie La Salle ◽  
Christopher Oakes ◽  
Jacquetta Trasler
Keyword(s):  
Dna Methylation ◽  
Germ Cell ◽  
Germ Cells ◽  
Epigenetic Modification ◽  
Methylation Pattern ◽  
Chromosome 9 ◽  
Specific Gene ◽  
Global Methylation ◽  
Dna Methylation Pattern ◽  
Methylation Patterns

Background: DNA methylation is an epigenetic modification involved in gene expression, genome stability, and genomic imprinting. In the male, methylation patterns are initially erased in primordial germ cells (PGCs) as they enter the gonadal ridge; methylation patterns are then acquired on CpG dinucleotides during gametogenesis. Correct pattern establishment is essential for normal spermatogenesis. To date, the characterization and timing of methylation pattern acquisition in PGCs has been described using a limited number of specific gene loci. This study aimed to describe DNA methylation pattern establishment dynamics during male gametogenesis through global methylation profiling techniques in a mouse model. Methods: Using a chromosome based approach, primers were designed for 24 regions spanning chromosome 9; intergenic, non-repeat, non-CpG island sequences were chosen for study based on previous evidence that these types of sequences are targets for testis-specific methylation events. The percent methylation was determined in each region by quantitative analysis of DNA methylation using real-time PCR (qAMP). The germ cell-specific pattern was determined by comparing methylation between spermatozoa and liver. To examine methylation in developing germ cells, spermatogonia from 2 day- and 6 day-old Oct4-GFP (green fluorescent protein) mice were isolated using fluorescence activated cell sorting. Results: As compared to liver, four loci were hypomethylated and five loci were hypermethylated in spermatozoa, supporting previous results indicating a unique methylation pattern in male germ cells. Only one region was hypomethylated and no regions were hypermethylated in day 6 spermatogonia as compared to mature spermatozoa, signifying that the bulk of DNA methylation is established prior to type A spermatogonia. The methylation in day 2 spermatogonia, germ cells that are just commencing mitosis, revealed differences of 15-20% compared to day 6 spermatogonia at five regions indicating that the most crucial phase of DNA methylation acquisition occurs prenatally. Conclusion: Together, these studies provide further evidence that germ cell methylation patterns differ from those in somatic tissues and suggest that much of methylation at intergenic sites is acquired during prenatal germ cell development. (Supported by CIHR)

scholarly journals Profiling DNA Methylation Based on Next-Generation Sequencing Approaches: New Insights and Clinical Applications

Genes ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 429 ◽  
Author(s):  
Daniela Barros-Silva ◽  
C. Marques ◽  
Rui Henrique ◽  
Carmen Jerónimo
Keyword(s):  
Dna Methylation ◽  
Next Generation Sequencing ◽  
High Throughput Sequencing ◽  
Epigenetic Modification ◽  
Response To Therapy ◽  
Next Generation ◽  
Sequencing Technologies ◽  
Prognosis And Prediction ◽  
Novel Biomarkers ◽  
Generation Sequencing

DNA methylation is an epigenetic modification that plays a pivotal role in regulating gene expression and, consequently, influences a wide variety of biological processes and diseases. The advances in next-generation sequencing technologies allow for genome-wide profiling of methyl marks both at a single-nucleotide and at a single-cell resolution. These profiling approaches vary in many aspects, such as DNA input, resolution, coverage, and bioinformatics analysis. Thus, the selection of the most feasible method according with the project’s purpose requires in-depth knowledge of those techniques. Currently, high-throughput sequencing techniques are intensively used in epigenomics profiling, which ultimately aims to find novel biomarkers for detection, diagnosis prognosis, and prediction of response to therapy, as well as to discover new targets for personalized treatments. Here, we present, in brief, a portrayal of next-generation sequencing methodologies’ evolution for profiling DNA methylation, highlighting its potential for translational medicine and presenting significant findings in several diseases.

scholarly journals Fetal and Neonatal Exposure to the Endocrine Disruptor Methoxychlor Causes Epigenetic Alterations in Adult Ovarian Genes

Endocrinology ◽  
2009 ◽  
Vol 150 (10) ◽  
pp. 4681-4691 ◽  
Author(s):  
Aparna Mahakali Zama ◽  
Mehmet Uzumcu
Keyword(s):  
Dna Methylation ◽  
Dna Methyltransferase ◽  
Ovarian Function ◽  
Endocrine Disrupting Chemicals ◽  
Neonatal Exposure ◽  
Dna Hypermethylation ◽  
Promoter Regions ◽  
Altered Expression ◽  
Arbitrarily Primed Pcr ◽  
Methylation Patterns

Abstract Exposure to endocrine-disrupting chemicals during development could alter the epigenetic programming of the genome and result in adult-onset disease. Methoxychlor (MXC) and its metabolites possess estrogenic, antiestrogenic, and antiandrogenic activities. Previous studies showed that fetal/neonatal exposure to MXC caused adult ovarian dysfunction due to altered expression of key ovarian genes including estrogen receptor (ER)-β, which was down-regulated, whereas ERα was unaffected. The objective of the current study was to evaluate changes in global and gene-specific methylation patterns in adult ovaries associated with the observed defects. Rats were exposed to MXC (20 μg/kg·d or 100 mg/kg·d) between embryonic d 19 and postnatal d 7. We performed DNA methylation analysis of the known promoters of ERα and ERβ genes in postnatal d 50–60 ovaries using bisulfite sequencing and methylation-specific PCRs. Developmental exposure to MXC led to significant hypermethylation in the ERβ promoter regions (P < 0.05), whereas the ERα promoter was unaffected. We assessed global DNA methylation changes using methylation-sensitive arbitrarily primed PCR and identified 10 genes that were hypermethylated in ovaries from exposed rats. To determine whether the MXC-induced methylation changes were associated with increased DNA methyltransferase (DNMT) levels, we measured the expression levels of Dnmt3a, Dnmt3b, and Dnmt3l using semiquantitative RT-PCR. Whereas Dnmt3a and Dnmt3l were unchanged, Dnmt3b expression was stimulated in ovaries of the 100 mg/kg MXC group (P < 0.05), suggesting that increased DNMT3B may cause DNA hypermethylation in the ovary. Overall, these data suggest that transient exposure to MXC during fetal and neonatal development affects adult ovarian function via altered methylation patterns.

scholarly journals DNA methylation patterns–based subtype distinction and identification of soft tissue sarcoma prognosis

2020 ◽  
Author(s):  
Zhengyuan Wu ◽  
Miao Yu ◽  
Jing-yuan Fan ◽  
Zhen-pei Wen ◽  
Tian-yu Ren ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Soft Tissue ◽  
Clinical Features ◽  
Soft Tissue Sarcomas ◽  
Survival Prediction ◽  
Biological Functions ◽  
Promoter Regions ◽  
Patient Prognosis ◽  
Selection Operator ◽  
Methylation Patterns

Abstract Background: Soft tissue sarcomas (STSs) are heterogeneous at the clinical with a variable tendency of aggressive behavior. Methods: In this study, we constructed a specific DNA methylation-based classification to identify the distinct prognosis-subtypes of STSs based on the DNA methylation spectrum from the TCGA database.Results: Eventually, samples were clustered into four subgroups, and their survival curves were distinct from each other. Meanwhile, the samples in each subgroup reflected differentially in several clinical features. Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis was also conducted on the genes of the corresponding promoter regions of the above‐described specific methylation sites, revealing that these genes were mainly concentrated in certain cancer‑associated biological functions and pathways. In addition, we calculated the differences among clustered methylation sites and performed the specific methylation sites with LASSO algorithm. The selection operator algorithm was employed to derive a risk signature model, and a prognostic signature based on these methylation sites performed well for risk stratification in STSs patients. At last, a nomogram consisted of clinical features and risk score was developed for the survival prediction. Conclusion: In conclusion, this study declares that DNA methylation-based STSs subtype classification is highly relevant for future development of personalized therapy as it identifies the prediction value of patient prognosis.

scholarly journals The interplay between DNA methylation and sequence divergence in recent human evolution

2015 ◽  
Author(s):  
Irene Hernando-Herraez ◽  
Holger Heyn ◽  
Marcos Fernandez-Callejo ◽  
Enrique Vidal ◽  
Hugo Fernandez-Bellon ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Transcription Factor ◽  
Binding Sites ◽  
Incomplete Lineage Sorting ◽  
Epigenetic Modification ◽  
Transcription Factor Binding Sites ◽  
Transcription Factor Binding ◽  
Factor Binding ◽  
Methylation Patterns ◽  
Human Specific

DNA methylation is a key regulatory mechanism in mammalian genomes. Despite the increasing knowledge about this epigenetic modification, the understanding of human epigenome evolution is in its infancy. We used whole genome bisulfite sequencing to study DNA methylation and nucleotide divergence between human and great apes. We identified 360 and 210 differentially hypo- and hypermethylated regions (DMRs) in humans compared to non-human primates and estimated that 20% and 36% of these regions, respectively, were detectable throughout several human tissues. Human DMRs were enriched for specific histone modifications and contrary to expectations, the majority were located distal to transcription start sites, highlighting the importance of regions outside the direct regulatory context. We also found a significant excess of endogenous retrovirus elements in human-specific hypomethylated regions suggesting their association with local epigenetic changes. We also reported for the first time a close interplay between inter-species genetic and epigenetic variation in regions of incomplete lineage sorting, transcription factor binding sites and human differentially hypermethylated regions. Specifically, we observed an excess of human-specific substitutions in transcription factor binding sites located within human DMRs, suggesting that alteration of regulatory motifs underlies some human-specific methylation patterns. We also found that the acquisition of DNA hypermethylation in the human lineage is frequently coupled with a rapid evolution at nucleotide level in the neighborhood of these CpG sites. Taken together, our results reveal new insights into the mechanistic basis of human-specific DNA methylation patterns and the interpretation of inter-species non-coding variation.

scholarly journals Stochastic Modeling Reveals Kinetic Heterogeneity in Post-replication DNA Methylation

2019 ◽  
Author(s):  
Luis Busto-Moner ◽  
Julien Morival ◽  
Arjang Fahim ◽  
Zachary Reitz ◽  
Timothy L. Downing ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Dna Methylation ◽  
Rate Constants ◽  
Cytosine Methylation ◽  
Temporal Dynamics ◽  
Epigenetic Modification ◽  
Embryonic Stem ◽  
Likelihood Estimation ◽  
Dna Methyltransferases ◽  
Methylation Patterns

AbstractDNA methylation is a heritable epigenetic modification that plays an essential role in mammalian development. Genomic methylation patterns are dynamically maintained, with DNA methyltransferases mediating inheritance of methyl marks onto nascent DNA over cycles of replication. A recently developed experimental technique employing immunoprecipitation of bromodeoxyuridine labeled nascent DNA followed by bisulfite sequencing (Repli-BS) measures post-replication temporal evolution of cytosine methylation, thus enabling genome-wide monitoring of methylation maintenance. In this work, we combine statistical analysis and stochastic mathematical modeling to analyze Repli-BS data from human embryonic stem cells. We estimate site-specific kinetic rate constants for the restoration of methyl marks on >10 million uniquely mapped cytosines within the CpG (cytosine-phosphate-guanine) dinucleotide context across the genome using Maximum Likelihood Estimation. We find that post-replication remethylation rate constants span approximately two orders of magnitude, with half-lives of per-site recovery of steady-state methylation levels ranging from shorter than ten minutes to five hours and longer. Furthermore, we find that kinetic constants of maintenance methylation are correlated among neighboring CpG sites. Stochastic mathematical modeling provides insight to the biological mechanisms underlying the inference results, suggesting that enzyme processivity and/or collaboration can produce the observed kinetic correlations. Our combined statistical/mathematical modeling approach expands the utility of genomic datasets and disentangles heterogeneity in methylation patterns arising from replication-associated temporal dynamics versus stable cell-to-cell differences.

scholarly journals Dynamic DNA Methylation in Plant Growth and Development

2018 ◽  
Vol 19 (7) ◽  
pp. 2144 ◽  
Author(s):  
Arthur Bartels ◽  
Qiang Han ◽  
Pooja Nair ◽  
Liam Stacey ◽  
Hannah Gaynier ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Plant Growth ◽  
Growth And Development ◽  
Genome Stability ◽  
Epigenetic Modification ◽  
Plant Growth And Development ◽  
Complex Dynamic ◽  
Dynamic Changes ◽  
The Common ◽  
Methylation Patterns

DNA methylation is an epigenetic modification required for transposable element (TE) silencing, genome stability, and genomic imprinting. Although DNA methylation has been intensively studied, the dynamic nature of methylation among different species has just begun to be understood. Here we summarize the recent progress in research on the wide variation of DNA methylation in different plants, organs, tissues, and cells; dynamic changes of methylation are also reported during plant growth and development as well as changes in response to environmental stresses. Overall DNA methylation is quite diverse among species, and it occurs in CG, CHG, and CHH (H = A, C, or T) contexts of genes and TEs in angiosperms. Moderately expressed genes are most likely methylated in gene bodies. Methylation levels decrease significantly just upstream of the transcription start site and around transcription termination sites; its levels in the promoter are inversely correlated with the expression of some genes in plants. Methylation can be altered by different environmental stimuli such as pathogens and abiotic stresses. It is likely that methylation existed in the common eukaryotic ancestor before fungi, plants and animals diverged during evolution. In summary, DNA methylation patterns in angiosperms are complex, dynamic, and an integral part of genome diversity after millions of years of evolution.

scholarly journals The Impact of Natural Dietary Compounds and Food-Borne Mycotoxins on DNA Methylation and Cancer

Cells ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 2004 ◽  
Author(s):  
Terisha Ghazi ◽  
Thilona Arumugam ◽  
Ashmika Foolchand ◽  
Anil A. Chuturgoon
Keyword(s):  
Dna Methylation ◽  
Bioactive Compounds ◽  
Epigenetic Modification ◽  
Bioactive Molecules ◽  
Methyl Donors ◽  
Food Borne ◽  
One Carbon Metabolism ◽  
Aberrant Dna Methylation ◽  
Methylation Patterns ◽  
The Impact

Cancer initiation and progression is an accumulation of genetic and epigenetic modifications. DNA methylation is a common epigenetic modification that regulates gene expression, and aberrant DNA methylation patterns are considered a hallmark of cancer. The human diet is a source of micronutrients, bioactive molecules, and mycotoxins that have the ability to alter DNA methylation patterns and are thus a contributing factor for both the prevention and onset of cancer. Micronutrients such as betaine, choline, folate, and methionine serve as cofactors or methyl donors for one-carbon metabolism and other DNA methylation reactions. Dietary bioactive compounds such as curcumin, epigallocatechin-3-gallate, genistein, quercetin, resveratrol, and sulforaphane reactivate essential tumor suppressor genes by reversing aberrant DNA methylation patterns, and therefore, they have shown potential against various cancers. In contrast, fungi-contaminated agricultural foods are a source of potent mycotoxins that induce carcinogenesis. In this review, we summarize the existing literature on dietary micronutrients, bioactive compounds, and food-borne mycotoxins that affect DNA methylation patterns and identify their potential in the onset and treatment of cancer.

Sign in / Sign up

Export Citation Format

Share Document