DNA HYPERMETHYLATION ON MULTIPLE CpG ISLANDS ASSOCIATED WITH INCREASED DNA METHYLTRANSFERASE DNMT1 PROTEIN EXPRESSION DURING MULTISTAGE UROTHELIAL CARCINOGENESIS

2005 ◽  
Vol 173 (5) ◽  
pp. 1767-1771 ◽  
Author(s):  
TOHRU NAKAGAWA ◽  
YAE KANAI ◽  
SAORI USHIJIMA ◽  
TADAICHI KITAMURA ◽  
TADAO KAKIZOE ◽  
...  
2020 ◽  
Vol 40 (8) ◽  
pp. 1854-1869
Author(s):  
Keith A. Strand ◽  
Sizhao Lu ◽  
Marie F. Mutryn ◽  
Linfeng Li ◽  
Qiong Zhou ◽  
...  

Objective: Our recent work demonstrates that PTEN (phosphatase and tensin homolog) is an important regulator of smooth muscle cell (SMC) phenotype. SMC-specific PTEN deletion promotes spontaneous vascular remodeling and PTEN loss correlates with increased atherosclerotic lesion severity in human coronary arteries. In mice, PTEN overexpression reduces plaque area and preserves SMC contractile protein expression in atherosclerosis and blunts Ang II (angiotensin II)-induced pathological vascular remodeling, suggesting that pharmacological PTEN upregulation could be a novel therapeutic approach to treat vascular disease. Approach and Results: To identify novel PTEN activators, we conducted a high-throughput screen using a fluorescence based PTEN promoter-reporter assay. After screening ≈3400 compounds, 11 hit compounds were chosen based on level of activity and mechanism of action. Following in vitro confirmation, we focused on 5-azacytidine, a DNMT1 (DNA methyltransferase-1) inhibitor, for further analysis. In addition to PTEN upregulation, 5-azacytidine treatment increased expression of genes associated with a differentiated SMC phenotype. 5-Azacytidine treatment also maintained contractile gene expression and reduced inflammatory cytokine expression after PDGF (platelet-derived growth factor) stimulation, suggesting 5-azacytidine blocks PDGF-induced SMC de-differentiation. However, these protective effects were lost in PTEN-deficient SMCs. These findings were confirmed in vivo using carotid ligation in SMC-specific PTEN knockout mice treated with 5-azacytidine. In wild type controls, 5-azacytidine reduced neointimal formation and inflammation while maintaining contractile protein expression. In contrast, 5-azacytidine was ineffective in PTEN knockout mice, indicating that the protective effects of 5-azacytidine are mediated through SMC PTEN upregulation. Conclusions: Our data indicates 5-azacytidine upregulates PTEN expression in SMCs, promoting maintenance of SMC differentiation and reducing pathological vascular remodeling in a PTEN-dependent manner.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bokyung Ahn ◽  
Yang Seok Chae ◽  
Soo Kyung Lee ◽  
Moa Kim ◽  
Hyeon Soo Kim ◽  
...  

AbstractAdenylate kinase 5 (AK5) belongs to the adenylate kinase family that catalyses reversible phosphate transfer between adenine nucleotides, and it is related to various energetic signalling mechanisms. However, the role of AK5 in colorectal cancer (CRC) has not been reported. In this study, AK5 was significantly hypermethylated in CRC compared to adjacent normal tissues (P < 0.0001) and normal tissues (P = 0.0015). Although the difference in mRNA expression was not statistically significant in all of them, the selected 49 cases of CRC tissues with AK5 hypermethylation with the cut off value of 40% showed a significant inverse correlation with mRNA expression (P = 0.0003). DNA methylation of AK5 promoter significantly decreased and AK5 expression recovered by 5-aza-2′-deoxycytidine, DNA methyltransferase inhibitor in CRC cell lines. In addition, AK5 promoter activity significantly decreased due to DNA methyltransferase, and it increased due to 5-aza. Moreover, AK5 regulated the phosphorylated AMPK and mTOR phosphorylation and inhibited the cell migration and cell invasion in CRC cell lines. Furthermore, low AK5 expression is associated with poor differentiation (P = 0.014). These results demonstrate that the AK5 promoter is frequently hypermethylated and induced methylation-mediated gene down-regulation. AK5 expression regulates AMPK/mTOR signalling and may be closely related to metastasis in colorectal adenocarcinoma.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Yng-Tay Chen ◽  
Wei-De Lin ◽  
Wen-Ling Liao ◽  
Ya-Ching Tsai ◽  
Jiunn-Wang Liao ◽  
...  

Abstract Epigenetics alternation of non-genetic variation and genome-wide association study proven allelic variants may associate with insulin secretion in type 2 diabetes (T2D) development. We analyzed promoter DNA methylation array to evaluate the associated with increased susceptibility to T2D (30 cases, 10 controls) and found 1,091 gene hypermethylated in promoter regions. We performed the association study of T2D and found 698 single nucleotide polymorphisms in exon and promoter sites by using 2,270 subjects (560 cases, 1,710 controls). A comparison of DNA hypermethylation and gene silencing of mouse T2D results in our T2D patients’ results showed that the 5′-nucleotidase, cytosolic II (NT5C2) and fucosyltransferase 8 (FUT8) genes were strongly associated with increased susceptibility to T2D. DNA hypermethylation in promoter regions reduced NT5C2 gene expression, but not FUT8 in T2D patients. NT5C2 protein expression was decreased in pancreatic β-cells from T2D mice. Transient transfection NT5C2 into RIN-m5F cells down-regulated DNA methyltransferase I (DNMT1) expression and up-regulation of the insulin receptor. Moreover, NT5C2 knockdown induced in DNMT1 overexpression and insulin receptor inhibition. Taken together, these results showed that NT5C2 epigenetically regulated insulin receptor in patients and mice with T2D, and maybe provide for T2D therapy strategy.


Endocrinology ◽  
2009 ◽  
Vol 150 (10) ◽  
pp. 4681-4691 ◽  
Author(s):  
Aparna Mahakali Zama ◽  
Mehmet Uzumcu

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 &lt; 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 &lt; 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.


2011 ◽  
Vol 53 (2) ◽  
pp. 167-174 ◽  
Author(s):  
Sylvia Hartmann ◽  
Marcin Szaumkessel ◽  
Itziar Salaverria ◽  
Ronald Simon ◽  
Guido Sauter ◽  
...  

Author(s):  
Priyanka Singh ◽  
Sanjay Kumar Bhadada ◽  
Divya Dahiya ◽  
Uma Nahar Saikia ◽  
Ashutosh Kumar Arya ◽  
...  

Abstract Purpose Glial cells missing 2 (GCM2), a zinc finger-transcription factor, is essentially required for the development of parathyroid glands. We sought to identify if the epigenetic alterations in the GCM2 transcription are involved in the pathogenesis of sporadic parathyroid adenoma. In addition, we examined the association between promoter methylation and histone modifications with disease indices. Experimental design mRNA and protein expression of GCM2 were analyzed by RT-qPCR and immunohistochemistry in 33 adenomatous and 10 control parathyroid tissues. DNA methylation and histone methylation/acetylation of GCM2 promoter were measured by bisulfite sequencing and ChIP-qPCR. Additionally, we investigated the role of epigenetic modifications on GCM2 and DNA methyltransferase 1 (DNMT1) expression in PTH-C1 cells by treating with 5-aza 2’deoxycytidine (DAC) and BRD4770 and assessed for GCM2 mRNA and DNMT1 protein levels. Results mRNA and protein expression of GCM2 were lower in sporadic adenomatous than in control parathyroid tissues. This reduction correlated with hypermethylation (P&lt;0.001) and higher H3K9me3 levels in GCM2 promoter (P&lt;0.04) in adenomas. In PTH-C1 cells, DAC treatment resulted in increased GCM2 transcription and decreased DNMT1 protein expression, while cells treated with the BRD4770 showed reduced H3K9me3 levels but a non-significant change in GCM2 transcription. Conclusion These findings suggest the concurrent association of promoter hypermethylation and higher H3K9me3 with the repression of GCM2 expression in parathyroid adenomas. Treatment with DAC restored GCM2 expression in PTH-C1 cells. Our results showed a possible epigenetic landscape in the tumorigenesis of parathyroid adenoma and also that DAC may be promising avenues of research for parathyroid adenoma therapeutics.


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