DNA methylation profiles in precancerous tissue and cancers: carcinogenetic risk estimation and prognostication based on DNA methylation status

Epigenomics ◽  
2010 ◽  
Vol 2 (3) ◽  
pp. 467-481 ◽  
Author(s):  
Eri Arai ◽  
Yae Kanai
Keyword(s):  
Dna Methylation ◽  
Risk Estimation ◽  
Methylation Status ◽  
Precancerous Tissue

DNA Methylation Status of Mash2 in Lungs of Somatic Cell Cloning Bovines*

2010 ◽  
Vol 37 (9) ◽  
pp. 960-966 ◽  
Author(s):  
Jie CHEN ◽  
Dong-Jie LI ◽  
Cui ZHANG ◽  
Ning LI ◽  
Shi-Jie LI
Keyword(s):  
Dna Methylation ◽  
Somatic Cell ◽  
Methylation Status ◽  
Cell Cloning

scholarly journals Epigenetic Changes During Mechanically Induced Osteogenic Lineage Commitment

2015 ◽  
Vol 137 (2) ◽  
Author(s):  
Julia C. Chen ◽  
Mardonn Chua ◽  
Raymond B. Bellon ◽  
Christopher R. Jacobs
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Shear Stress ◽  
Fluid Shear Stress ◽  
Methylation Status ◽  
Lineage Commitment ◽  
Fluid Shear ◽  
Osteogenic Lineage ◽  
Osteogenic Markers ◽  
Heterochromatin Structure

Osteogenic lineage commitment is often evaluated by analyzing gene expression. However, many genes are transiently expressed during differentiation. The availability of genes for expression is influenced by epigenetic state, which affects the heterochromatin structure. DNA methylation, a form of epigenetic regulation, is stable and heritable. Therefore, analyzing methylation status may be less temporally dependent and more informative for evaluating lineage commitment. Here we analyzed the effect of mechanical stimulation on osteogenic differentiation by applying fluid shear stress for 24 hr to osteocytes and then applying the osteocyte-conditioned medium (CM) to progenitor cells. We analyzed gene expression and changes in DNA methylation after 24 hr of exposure to the CM using quantitative real-time polymerase chain reaction and bisulfite sequencing. With fluid shear stress stimulation, methylation decreased for both adipogenic and osteogenic markers, which typically increases availability of genes for expression. After only 24 hr of exposure to CM, we also observed increases in expression of later osteogenic markers that are typically observed to increase after seven days or more with biochemical induction. However, we observed a decrease or no change in early osteogenic markers and decreases in adipogenic gene expression. Treatment of a demethylating agent produced an increase in all genes. The results indicate that fluid shear stress stimulation rapidly promotes the availability of genes for expression, but also specifically increases gene expression of later osteogenic markers.

scholarly journals DNA methylation differs extensively between strains of the same geographical origin and changes with age in Daphnia magna

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Jack Hearn ◽  
Fiona Plenderleith ◽  
Tom J. Little
Keyword(s):  
Dna Methylation ◽  
Caloric Restriction ◽  
Daphnia Magna ◽  
Single Gene ◽  
Methylation Status ◽  
Strain Differences ◽  
Life History Trait ◽  
Food Level ◽  
Epigenetic Clock ◽  
Age Related

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.

scholarly journals DNA methylome signatures of prenatal exposure to synthetic glucocorticoids in hippocampus and peripheral whole blood of female guinea pigs in early life

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Aya Sasaki ◽  
Margaret E. Eng ◽  
Abigail H. Lee ◽  
Alisa Kostaki ◽  
Stephen G. Matthews
Keyword(s):  
Dna Methylation ◽  
Whole Blood ◽  
Guinea Pigs ◽  
Critical Role ◽  
Methylation Status ◽  
Peripheral Tissues ◽  
Epigenetic Biomarkers ◽  
Differentially Methylated Genes ◽  
Increased Risk ◽  
Synthetic Glucocorticoids

AbstractSynthetic glucocorticoids (sGC) are administered to women at risk of preterm delivery, approximately 10% of all pregnancies. In animal models, offspring exposed to elevated glucocorticoids, either by administration of sGC or endogenous glucocorticoids as a result of maternal stress, show increased risk of developing behavioral, endocrine, and metabolic dysregulation. DNA methylation may play a critical role in long-lasting programming of gene regulation underlying these phenotypes. However, peripheral tissues such as blood are often the only accessible source of DNA for epigenetic analyses in humans. Here, we examined the hypothesis that prenatal sGC administration alters DNA methylation signatures in guinea pig offspring hippocampus and whole blood. We compared these signatures across the two tissue types to assess epigenetic biomarkers of common molecular pathways affected by sGC exposure. Guinea pigs were treated with sGC or saline in late gestation. Genome-wide modifications of DNA methylation were analyzed at single nucleotide resolution using reduced representation bisulfite sequencing in juvenile female offspring. Results indicate that there are tissue-specific as well as common methylation signatures of prenatal sGC exposure. Over 90% of the common methylation signatures associated with sGC exposure showed the same directionality of change in methylation. Among differentially methylated genes, 134 were modified in both hippocampus and blood, of which 61 showed methylation changes at identical CpG sites. Gene pathway analyses indicated that prenatal sGC exposure alters the methylation status of gene clusters involved in brain development. These data indicate concordance across tissues of epigenetic programming in response to alterations in glucocorticoid signaling.

scholarly journals DNA Methylation Based Molecular Subtypes Predict Prognosis in Breast Cancer Patients

2021 ◽  
Vol 28 ◽  
pp. 107327482098851
Author(s):  
Zeng-Hong Wu ◽  
Yun Tang ◽  
Yan Zhou
Keyword(s):  
Breast Cancer ◽  
Dna Methylation ◽  
Molecular Subtypes ◽  
Methylation Status ◽  
The Cancer Genome Atlas ◽  
Training Dataset ◽  
Consensus Clustering ◽  
Breast Cancer Patients ◽  
Cancer Subtypes ◽  
Novel Biomarkers

Background: Epigenetic changes are tightly linked to tumorigenesis development and malignant transformation’ However, DNA methylation occurs earlier and is constant during tumorigenesis. It plays an important role in controlling gene expression in cancer cells. Methods: In this study, we determining the prognostic value of molecular subtypes based on DNA methylation status in breast cancer samples obtained from The Cancer Genome Atlas database (TCGA). Results: Seven clusters and 204 corresponding promoter genes were identified based on consensus clustering using 166 CpG sites that significantly influenced survival outcomes. The overall survival (OS) analysis showed a significant prognostic difference among the 7 groups (p<0.05). Finally, a prognostic model was used to estimate the results of patients on the testing set based on the classification findings of a training dataset DNA methylation subgroups. Conclusions: The model was found to be important in the identification of novel biomarkers and could be of help to patients with different breast cancer subtypes when predicting prognosis, clinical diagnosis and management.

scholarly journals Epigenetic Contribution and Genomic Imprinting Dlk1-Dio3 miRNAs in Systemic Lupus Erythematosus

Genes ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 680
Author(s):  
Rujuan Dai ◽  
Zhuang Wang ◽  
S. Ansar Ahmed
Keyword(s):  
Systemic Lupus Erythematosus ◽  
Dna Methylation ◽  
Lupus Erythematosus ◽  
Critical Role ◽  
Methylation Status ◽  
Transcriptional Level ◽  
Dna Hypomethylation ◽  
Systemic Lupus ◽  
Multiple Organs ◽  
Genetic Imprinting

Systemic lupus erythematosus (SLE) is a multifactorial autoimmune disease that afflicts multiple organs, especially kidneys and joints. In addition to genetic predisposition, it is now evident that DNA methylation and microRNAs (miRNAs), the two major epigenetic modifications, are critically involved in the pathogenesis of SLE. DNA methylation regulates promoter accessibility and gene expression at the transcriptional level by adding a methyl group to 5′ cytosine within a CpG dinucleotide. Extensive evidence now supports the importance of DNA hypomethylation in SLE etiology. miRNAs are small, non-protein coding RNAs that play a critical role in the regulation of genome expression. Various studies have identified the signature lupus-related miRNAs and their functional contribution to lupus incidence and progression. In this review, the mutual interaction between DNA methylation and miRNAs regulation in SLE is discussed. Some lupus-associated miRNAs regulate DNA methylation status by targeting the DNA methylation enzymes or methylation pathway-related proteins. On the other hand, DNA hyper- and hypo-methylation are linked with dysregulated miRNAs expression in lupus. Further, we specifically discuss the genetic imprinting Dlk1-Dio3 miRNAs that are subjected to DNA methylation regulation and are dysregulated in several autoimmune diseases, including SLE.

scholarly journals Correlation of methylation status in MTHFR promoter region with recurrent pregnancy loss

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Mai Mahmoud Shaker ◽  
Taghreed Abdelmoniem shalabi ◽  
Khalda said Amr
Keyword(s):  
Dna Methylation ◽  
Dna Sequences ◽  
Promoter Region ◽  
Pregnancy Loss ◽  
Recurrent Pregnancy Loss ◽  
Methylation Status ◽  
Control Group ◽  
Case Group ◽  
Methyl Radical ◽  
Fertile Women

Abstract Background DNA methylation is an epigenetic process for modifying transcription factors in various genes. Methylenetetrahydrofolate reductase (MTHFR) stimulates synthesis of methyl radical in the homocysteine cycle and delivers methyl groups needed in DNA methylation. Furthermore, numerous studies have linked gene polymorphisms of this enzyme with a larger risk of recurrent pregnancy loss (RPL), yet scarce information is available concerning the association between epigenetic deviations in this gene and RPL. Hypermethylation at precise DNA sequences can function as biomarkers for a diversity of diseases. We aimed by this study to evaluate the methylation status of the promoter region of MTHFR gene in women with RPL compared to healthy fertile women. It is a case–control study. Hundred RPL patients and hundred healthy fertile women with no history of RPL as controls were recruited. MTHFR C677T was assessed by polymerase chain reaction-restriction fragment length polymorphism (RFLP). Quantitative evaluation of DNA methylation was performed by high-resolution melt analysis by real-time PCR. Results The median of percentage of MTHFR promoter methylation in RPL cases was 6.45 [0.74–100] vs. controls was 4.50 [0.60–91.7], P value < 0.001. In the case group, 57 hypermethylated and 43 normo-methylated among RPL patients vs. 40 hypermethylated and 60 normo-methylated among controls, P< 0.005. Frequency of T allele in C677T MTHFR gene among RPL patients was 29% vs. 23% among the control group; C allele vs. T allele: odds ratio (OR) = 1.367 (95% confidence interval (CI) 0.725–2.581). Conclusion Findings suggested a significant association between hypermethylation of the MTHFR promoter region in RPL patients compared to healthy fertile women.

scholarly journals Whole-Genome DNA Methylation Analysis in Hydrogen Peroxide Overproducing Transgenic Tobacco Resistant to Biotic and Abiotic Stresses

Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 178
Author(s):  
Ana L. Villagómez-Aranda ◽  
Luis F. García-Ortega ◽  
Irineo Torres-Pacheco ◽  
Ramón G. Guevara-González
Keyword(s):  
Hydrogen Peroxide ◽  
Dna Methylation ◽  
Transgenic Tobacco ◽  
Stress Responses ◽  
Abiotic Stresses ◽  
Methylation Status ◽  
Physiological Adaptation ◽  
Whole Genome ◽  
Sequencing Analysis ◽  
Biotic And Abiotic Stresses

Epigenetic regulation is a key component of stress responses, acclimatization and adaptation processes in plants. DNA methylation is a stable mark plausible for the inheritance of epigenetic traits, such that it is a potential scheme for plant breeding. However, the effect of modulators of stress responses, as hydrogen peroxide (H2O2), in the methylome status has not been elucidated. A transgenic tobacco model to the CchGLP gene displayed high H2O2 endogen levels correlated with biotic and abiotic stresses resistance. The present study aimed to determine the DNA methylation status changes in the transgenic model to obtain more information about the molecular mechanism involved in resistance phenotypes. The Whole-genome bisulfite sequencing analysis revealed a minimal impact of overall levels and distribution of methylation. A total of 9432 differential methylated sites were identified in distinct genome regions, most of them in CHG context, with a trend to hypomethylation. Of these, 1117 sites corresponded to genes, from which 83 were also differentially expressed in the plants. Several genes were associated with respiration, energy, and calcium signaling. The data obtained highlighted the relevance of the H2O2 in the homeostasis of the system in stress conditions, affecting at methylation level and suggesting an association of the H2O2 in the physiological adaptation to stress functional linkages may be regulated in part by DNA methylation.

Progressive alteration of DNA methylation of Alu, MGMT, MINT2, and TFPI2 genes in colonic mucosa during colorectal cancer development

2021 ◽  
pp. 1-6
Author(s):  
Ben Kang ◽  
Hyun Seok Lee ◽  
Seong Woo Jeon ◽  
Soo Yeun Park ◽  
Gyu Seog Choi ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Dna Methylation ◽  
Healthy Subjects ◽  
Large Scale ◽  
Methylation Status ◽  
Clinical Information ◽  
Field Cancerization ◽  
Aberrant Methylation ◽  
Clinical Value ◽  
Mortality And Morbidity

BACKGROUND: Colorectal cancer (CRC) is one of the leading causes of mortality and morbidity in the world. It is characterized by different pathways of carcinogenesis and is a heterogeneous disease with diverse molecular landscapes that reflect histopathological and clinical information. Changes in the DNA methylation status of colon epithelial cells have been identified as critical components in CRC development and appear to be emerging biomarkers for the early detection and prognosis of CRC. OBJECTIVE: To explore the underlying disease mechanisms and identify more effective biomarkers of CRC. METHODS: We compared the levels and frequencies of DNA methylation in 11 genes (Alu, APC, DAPK, MGMT, MLH1, MINT1, MINT2, MINT3, p16, RGS6, and TFPI2) in colorectal cancer and its precursor adenomatous polyp with normal tissue of healthy subjects using pyrosequencing and then evaluated the clinical value of these genes. RESULTS: Aberrant methylation of Alu, MGMT, MINT2, and TFPI2 genes was progressively accumulated during the normal-adenoma-carcinoma progression. Additionally, CGI methylation occurred either as an adenoma-associated event for APC, MLH1, MINT1, MINT31, p16, and RGS6 or a tumor-associated event for DAPK. Moreover, relatively high levels and frequencies of DAPK, MGMT, and TFPI2 methylation were detected in the peritumoral nonmalignant mucosa of cancer patients in a field-cancerization manner, as compared to normal mucosa from healthy subjects. CONCLUSION: This study identified several biomarkers associated with the initiation and progression of CRC. As novel findings, they may have important clinical implications for CRC diagnostic and prognostic applications. Further large-scale studies are needed to confirm these findings.

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