scholarly journals Electrochemically detecting DNA methylation in the EN1 gene promoter: implications for understanding ageing and disease

2020 ◽  
Vol 40 (11) ◽  
Author(s):  
Amy E. Morgan ◽  
Katie D. Acutt ◽  
Mark T. Mc Auley

Abstract There is a growing need for biomarkers which predict age-onset pathology. Although this is challenging, the methylome offers significant potential. Cancer is associated with the hypermethylation of many gene promoters, among which are developmental genes. Evolutionary theory suggests developmental genes arbitrate early-late life trade-offs, causing epimutations that increase disease vulnerability. Such genes could predict age-related disease. The aim of this work was to optimise an electrochemical procedure for the future investigation of a broad range of ageing-related pathologies. An electrochemical approach, which adopted three analytical techniques, was used to investigate DNA methylation in the engrailed-1 (EN1) gene promoter. Using synthetic single-stranded DNA, one technique was able to detect DNA at concentrations as low as 10 nM, with methylation status distinguishable at concentrations >25 nM. A negative correlation could be observed between % methylation of a heterogeneous solution and the key electrochemical parameter, charge transfer resistance (Rct; r = −0.982, P<0.01). The technique was applied to the breast cancer cell line Michigan Cancer Foundation-7 (MCF-7), where a similar correlation was observed (r = −0.965, P<0.01). These results suggest electrochemistry can effectively measure DNA methylation at low concentrations of DNA. This has implications for the future detection of age-related disease.

2014 ◽  
Vol 58 (1) ◽  
pp. 82-89 ◽  
Author(s):  
Stephane Flaviane de Oliveira Bezerra ◽  
Ludimila de Araújo Costa ◽  
Priscylla Alves Nascimento de Freitas ◽  
Naila Francis Paulo de Oliveira

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Jack Hearn ◽  
Fiona Plenderleith ◽  
Tom J. Little

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.


2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Zijian Chen ◽  
Zenghong Huang ◽  
Yanxin Luo ◽  
Qi Zou ◽  
Liangliang Bai ◽  
...  

Abstract Background Neurotrophic tropomyosin receptor kinases (NTRKs) are a gene family function as oncogene or tumor suppressor gene in distinct cancers. We aimed to investigate the methylation and expression profiles and prognostic value of NTRKs gene in colorectal cancer (CRC). Methods An analysis of DNA methylation and expression profiles in CRC patients was performed to explore the critical methylations within NTRKs genes. The methylation marker was validated in a retrospectively collected cohort of 229 CRC patients and tested in other tumor types from TCGA. DNA methylation status was determined by quantitative methylation-specific PCR (QMSP). Results The profiles in six CRC cohorts showed that NTRKs gene promoter was more frequently methylated in CRC compared to normal mucosa, which was associated with suppressed gene expression. We identified a specific methylated region within NTRK3 promoter targeted by cg27034819 and cg11525479 that best predicted survival outcome in CRC. NTRK3 promoter methylation showed independently predictive value for survival outcome in the validation cohort (P = 0.004, HR 2.688, 95% CI [1.355, 5.333]). Based on this, a nomogram predicting survival outcome was developed with a C-index of 0.705. Furthermore, the addition of NTRK3 promoter methylation improved the performance of currently-used prognostic model (AIC: 516.49 vs 513.91; LR: 39.06 vs 43.64, P = 0.032). Finally, NTRK3 promoter methylation also predicted survival in other tumors, including pancreatic cancer, glioblastoma and stomach adenocarcinoma. Conclusions This study highlights the essential value of NTRK3 methylation in prognostic evaluation and the potential to improve current prognostic models in CRC and other tumors.


2014 ◽  
Vol 34 (suppl_1) ◽  
Author(s):  
Jessilyn Dunn ◽  
Haiwei Qiu ◽  
Soyeon Kim ◽  
Daudi Jjingo ◽  
Ryan Hoffman ◽  
...  

Atherosclerosis preferentially occurs in arterial regions of disturbed blood flow (d-flow), which alters gene expression, endothelial function, and atherosclerosis. Here, we show that d-flow regulates genome-wide DNA methylation patterns in a DNA methyltransferase (DNMT)-dependent manner. We found that d-flow induced expression of DNMT1, but not DNMT3a or DNMT3b, in mouse arterial endothelium in vivo and in cultured endothelial cells by oscillatory shear (OS) compared to unidirectional laminar shear in vitro. The DNMT inhibitor 5-Aza-2’deoxycytidine (5Aza) or DNMT1 siRNA significantly reduced OS-induced endothelial inflammation. Moreover, 5Aza reduced lesion formation in two atherosclerosis models using ApoE-/- mice (western diet for 3 months and the partial carotid ligation model with western diet for 3 weeks). To identify the 5Aza mechanisms, we conducted two genome-wide studies: reduced representation bisulfite sequencing (RRBS) and transcript microarray using endothelial-enriched gDNA and RNA, respectively, obtained from the partially-ligated left common carotid artery (LCA exposed to d-flow) and the right contralateral control (RCA exposed to s-flow) of mice treated with 5Aza or vehicle. D-flow induced DNA hypermethylation in 421 gene promoters, which was significantly prevented by 5Aza in 335 genes. Systems biological analyses using the RRBS and the transcriptome data revealed 11 mechanosensitive genes whose promoters were hypermethylated by d-flow but rescued by 5Aza treatment. Of those, five genes contain hypermethylated cAMP-response-elements in their promoters, including the transcription factors HoxA5 and Klf3. Their methylation status could serve as a mechanosensitive master switch in endothelial gene expression. Our results demonstrate that d-flow controls epigenomic DNA methylation patterns in a DNMT-dependent manner, which in turn alters endothelial gene expression and induces atherosclerosis.


2021 ◽  
Author(s):  
Petros Georgopoulos ◽  
Maria Papaioannou ◽  
Soultana Markopoulou ◽  
Aikaterini Fragou ◽  
George Kouvatseas ◽  
...  

Abstract PurposeThe aim of this study was to explore the diagnostic potential of a panel of five hypermethylated gene promoters in bladder cancer. Individuals with primary BCa and control individuals matching the gender, age and smoking status of the cancer patients were recruited. DNA methylation was assessed for the gene promoters of RASSF1, RARβ, DAPK, hTERT and APC in urine samples collected by spontaneous urination. Fifty patients and 35 healthy controls were recruited, with average age of 70.26 years and average smoking status of 44.78 pack-years. In the BCa group, DNA methylation was detected in 27(61.4%) samples. RASSF1 was methylated in 52.2% of samples. Only 3(13.6%) samples from the control group were methylated, all in the RASSF1 gene promoter. The specificity and sensitivity of this panel of genes to diagnose BCa was 86% and 61% respectively. The RASSF1 gene could diagnose BCa with specificity 86.4% and sensitivity 52.3%. Promoter DNA methylation of this panel of five genes could be further investigated as urine biomarker for the diagnosis of BCa. The RASSF1 could be a single candidate biomarker for predicting BCa patients versus controls. Studies are required in order to develop a geographically adjusted diagnostic biomarker for BCa.Trial registration: ACTRN12620000258954


2018 ◽  
Vol 127 (04) ◽  
pp. 226-233 ◽  
Author(s):  
Makrina Karaglani ◽  
Georgia Ragia ◽  
Maria Panagopoulou ◽  
Ioanna Balgkouranidou ◽  
Evangelia Nena ◽  
...  

AbstractSulfonylureas are insulin secretagogues which act in pancreatic β cells by blocking the KATP channels encoded by KCNJ11 and ABCC8 genes. In the present study, a pharmacoepigenetic approach was applied for the first time, investigating the correlation of KCNJ11 and ABCC8 gene promoter methylation with sulfonylureas-induced mild hypoglycemic events as well as the KCNJ11 E23K genotype. Sodium bisulfite-treated genomic DNA of 171 sulfonylureas treated T2DM patients previously genotyped for KCNJ11 E23K, including 88 that had experienced drug-associated hypoglycemia and 83 that had never experienced hypoglycemia, were analyzed for DNA methylation of KCNJ11 and ABCC8 gene promoters via quantitative Methylation-Specific PCR. KCNJ11 methylation was detected in 19/88 (21.6%) of hypoglycemic and in 23/83 (27.7%) of non-hypoglycemic patients (p=0.353), while ABCC8 methylation in 6/83 (7.2%) of non-hypoglycemic and none (0/88) of the hypoglycemic patients (p=0.012). Methylation in at least one promoter (KCNJ11 or ABCC8) was significantly associated with non-hypoglycemic patients who are carriers of KCNJ11 EK allele (p=0.030). Our data suggest that ABCC8 but not KCNJ11 methylation is associated to hypoglycemic events in sulfonylureas-treated T2DM patients. Furthermore, it is demonstrated that the KCNJ11 E23K polymorphism in association to either of the two genes’ DNA methylation may have protective role against sulfonylurea-induced hypoglycemia.


2012 ◽  
Vol 27 ◽  
pp. 1
Author(s):  
A. Yuan ◽  
D. Peng ◽  
J. Sun ◽  
Y. Du ◽  
W. Li ◽  
...  

PLoS ONE ◽  
2015 ◽  
Vol 10 (3) ◽  
pp. e0120388 ◽  
Author(s):  
Fu-Hui Xiao ◽  
Yong-Han He ◽  
Qi-Gang Li ◽  
Huan Wu ◽  
Long-Hai Luo ◽  
...  

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 4386-4386
Author(s):  
Ye Zhao ◽  
Zi-xing Chen ◽  
Shao-yan Hu ◽  
Jian-nong Cen

Abstract The methylation at CpG island in the promoter region of a gene is one of the important epigenetic mechanism which regulates the gene activity. To study the DNA methylation pattern of WT1 gene promoter region within hematologic neoplastic cell lines and its correlation with WT1 gene expression by using the PCR-based methods. RT-PCR and Methylation-specific PCR were performed to study the WT1 gene expression in 8226, HL-60, Jurkat, K562, KG-1, NB4, Raji, SHI-1, U266 and U937 cell lines and the DNA methylation status in promoter region of WT1 gene. After treatment of U937 cell line by 5-aza-CdR, a demethylation inducing agent, the changes of WT1 gene expression level and the methylation status in its promter region in U937 cells was determined. Our Results showed that HL-60, K562, KG-1, NB4, SHI-1 cell lines demonstrated higher level of WT1 expression, while extremely low level was found in 8226, Jurkat, Raji, U266 and U937. The DNA hypermethylation in WT1 gene promoter region was identified in 8226, Jurkat, Raji, U266 and U937 cell lines. The WT1 gene expression in U937 was markedly enhanced after treatment with 5-aza-CdR in company with the decrease of methylated level and the increase of unmethylated level in its promoter region. These results indicate that modulation of the DNA methylation in WT1 promoter region is one of the epigenetic mechanisms to regulate its expression.


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