ObjectiveTo investigate the difference of DNA methylation before and after bariatric surgery.MethodThe relevant literatures of the research on the changes of DNA methylation level and gene expression regulation in blood and tissues before and after bariatric surgery were retrieved and reviewed.ResultsDNA methylation was an important method of epigenetic regulation in organisms and its role in bariatric surgery had been paid more and more attention in recent years. Existing studies had found that there were changes of DNA methylation in blood and tissues before and after bariatric surgery. The degree of methylation varies with different follow-up time after bariatric surgery and the same gene had different degrees of methylation in different tissues, and some even had the opposite results.ConclusionsDNA methylation levels before and after bariatric surgery are different in different tissues. And studies with larger sample size and longer follow-up time are needed, to further reveal relationship among DNA methylation, obesity, and bariatric surgery.
ObjectiveTo explore the clinical significance of promoter hypermethylation of O6-methylguanine-DNA methyltransferase (MGMT) in cholangiocarcinoma. MethodsPromoter methylation status of MGMT gene and expression of MGMT protein were detected in cholangiocarcinoma by methylationspecific PCR and immunohistochemical staining, respectively. ResultsAberrant methylation of MGMT gene was detected in 17 patients (47.2%). Twentyone cases showed negative immunoreactivities. Of 21 patients with negative MGMT expression, 14 patients had aberrant methylation of MGMT gene. In 15 patients with positive MGMT expression, aberrant methylation of MGMT gene was only found in three cases. There was a negative correlation between promoter methylation status of MGMT gene and the expression of MGMT protein (rs=-0.816, Plt;0.05). Promoter methylation status of MGMT gene was related to depth of invasion, degree of differentiation, and TNM stage (Plt;0.05), but not to age of patient, gender, pathological type, and lymph node metastasis (Pgt;0.05). ConclusionsHypermethylation of MGMT promoter is a frequency molecular event in cholangiocarcinoma and may be involved in carcinogenesis. Methylation status of MGMT gene may be used to evaluate malignant degree of cholangiocarcinoma.
ObjectiveRecent advancements in the researches on cholangiocarcinoma (CC) related genes methylation in CC were reviewed and the clinical significances of aberrant DNA methylation for the diagnosis and treatment of CC were discussed. MethodsRelevant literatures about the relation between CC-related genes methylation and CC published recently were collected and reviewed. ResultsThe genesis of CC resulted from abnormal expressions of many genes. Many researches had shown that the abnormal methylation of CC-related genes had a close relation with CC. Epigenetic alteration had been acknowledged as an important mechanism contributing to early CC carcinogenesis. ConclusionsAbnormal methylation of CC-related genes is related with CC. The detection of CC-related genes methylation might provide new specific biomarkers for early noninvasive diagnosis of this disease. Using epigenetic agents such as azacytidine to modulate the activities of DNA methyltransferase and reverse the methylation status of CC-related gene might be an attractive strategy for future treatment of CC, which could be combined with conventional therapies.
Lung cancer is the most common malignant tumor in the world and the leading cause of cancer-related death. Due to the lack of effective early diagnosis methods, the prognosis of lung cancer is poor, but compared with advanced lung cancer, the survival rate of early lung cancer is greatly improved. Therefore, early diagnosis of lung cancer is crucial. As a major epigenetic modification, DNA methylation plays an important role in the development of lung cancer. A large number of studies have shown that detection of tumor suppressor gene methylation is an ideal early diagnosis method for lung cancer. With the continuous improvement of detection technology, methylation detection of multiple genes can be achieved. And it is found that multi-gene methylation combined detection of tissue samples obtained by minimally invasive operation such as puncture of diseased tissue and puncture of lymph node tissue, as well as the noninvasive samples such as peripheral blood, bronchoalveolar lavage fluid and sputum have higher detection rate and higher sensitivity and specificity than single gene methylation. It is an ideal method for early diagnosis of lung cancer.
Objective To investigate the effects of DNA methyltransferase inhibitor (DNMTi) and histone deacetylase inhibitor (HDCAi) on expression of E-cadherin gene and invasiveness of cholangiocarcinoma cell. Methods According to different treatment, the QBC939 cells were divided into four groups: blank control group, hydralazine group, valproic acid group and hydralazine and valproic acid combined group. After 48 h, the expression of E-cadherin was evaluated by reverse transcription-PCR (RT-PCR), mehtylation specific PCR (MSP) and Western blot, the invasiveness of QBC939 cells was evaluated by Transwell method. Results There was no expression of E-cadherin mRNA and protien in blank control group and valproic acid group. The expressions of E-cadherin mRNA and protien in hydralazine and valproic acid combined group were higher than those in hydralazine group ( P ＜ 0.01), while the invasiveness of QBC939 cells of hydralazine and valproic acid combined group was much lower than that of blank control group, hydralazine group and valproic acid group ( P ＜ 0.01). Conclusion DNMTi and HDACi can synergistically re-express E-cadherin gene and weaken the invasiveness of QBC939 cell, which plays an important part in treatment of cholangiocarcinoma.
Pulmonary arterial hypertension (PAH) is a fatal and complex disease characterized by multifactorial involvement in pulmonary vascular remodeling, leading to heart failure. It is difficult to treat and has a poor long-term prognosis. Recent studies highlight the significant role of epigenetic modulation in the pathophysiological progression of PAH, offering new therapeutic approaches to improve clinical outcomes. This article summarizes the role of epigenetic modulation in the development and progression of PAH, focusing on deoxyribonucleic acid methylation, ribonucleic acid methylation, histone modifications, and non-coding ribonucleic acid, in order to understand the role of epigenetic modulation in PAH and identifying new evaluation indexes and therapeutic targets, thereby improving the prognosis of PAH.
Objective To identify the N6-methyladenosine (m6A)-related characteristic genes analyzed by gene clustering and immune cell infiltration in myocardial ischemia-reperfusion injury (MI/RI) after cardiopulmonary bypass through machine learning. Methods The differential genes associated with m6A methylation were screened by the dataset GSE132176 in GEO, the samples of the dataset were clustered based on the differential gene expression profile, and the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis of the differential genes of the m6A cluster after clustering were performed to determine the gene function of the m6A cluster. R software was used to determine the better models in machine learning of support vector machine (SVM) model and random forest (RF) model, which were used to screen m6A-related characteristic genes in MI/RI, and construct characteristic gene nomogram to predict the incidence of disease. R software was used to analyze the correlation between characteristic genes and immune cells, and the online website was used to build a characteristic gene regulatory network. Results In this dataset, a total of 5 m6A-related differential genes were screened, and the gene expression profiles were divided into two clusters for cluster analysis. The enrichment analysis of m6A clusters showed that these genes were mainly involved in regulating monocytes differentiation, response to lipopolysaccharides, response to bacteria-derived molecules, cellular response to decreased oxygen levels, DNA transcription factor binding, DNA-binding transcription activator activity, RNA polymerase Ⅱ specificity, NOD-like receptor signaling pathway, fluid shear stress and atherosclerosis, tumor necrosis factor signaling pathway, interleukin-17 signaling pathway. The RF model was determined by R software as the better model, which determined that METTL3, YTHDF1, RBM15B and METTL14 were characteristic genes of MI/RI, and mast cells, type 1 helper lymphocytes (Th1), type 17 helper lymphocytes (Th17), and macrophages were found to be associated with MI/RI after cardiopulmonary bypass in immune cell infiltration. Conclusion The four characteristic genes METTL3, YTHDF1, RBM15B and METTL14 are obtained by machine learning, while cluster analysis and immune cell infiltration analysis can better reveal the pathophysiological process of MI/RI.
The regulation of epigenetics on bone marrow mesenchymal stem cells (BMSCs) has been a research hot spot in medical area. This paper mainly summarizes the progress of the regulation of DNA methylation, histone acetylation, small interfering RNA (siRNA) induced gene silence and microRNA (miRNA) on BMSCs. Our analysis shows that the regulation of epigenetics on BMSCs plays a significant role in the repair of bone tissue, nervous tissue and cardiac muscle.
Objective To investigate the role of DNA methylation on regulation of cell apoptosis and proliferation in ischemia-reperfusion of small intestine. Methods Thirty-five male Wistar rats were randomly divided into normal group， sham operation group， and ischemia-reperfusion group. The apoptotic cell was assessed by TUNEL and electron microscopy and the expression of Ki-67 was examined by immunohistochemistry in the small intestinal parts （villi epithe-lium， crypt epithelium， and lamina propria mucosa of small intestine）. The DNA methylation was detected by DNA histo-endonuclease-linked detection of methylated DNA sites. Results ①The apoptotic positive cells increased at 3 h， 6 h，and 12 h after ischemia-reperfusion in the villi epithelium， crypt epithelium， and lamina propria mucosa of small intestine as compared with the normal group and sham operation group （P＜0.01）；Moreover， the apoptotic cells in the lamina propria mucosa of small intestine were identified as T cells by electron microscopy. ②The expressions of Ki-67 markedly increased at 3 h， 6 h， 12 h， and 24 h after ischemia-reperfusion in the villi epithelium cells as compared with the normal group and sham operation group （P＜0.01）. ③The weak expression of DNA methylation was found in the villi epith-elium and crypt epithelium in the normal group and sham operation group， the b expression was examined in the crypt epithelium cells nearby stem cell site in the ischemia-reperfusion of small intestine， the change of expression was gradually weak from crypt epithelium to villi epithelium. Conclusion This initial results indicate that the DNA methyl-ation in the ischemia-reperfusion of small intestine might regulate cell apoptosis and proliferation.
ObjectiveTo explore the accuracy of machine learning algorithms based on SHOX2 and RASSF1A methylation levels in predicting early-stage lung adenocarcinoma pathological types. MethodsA retrospective analysis was conducted on formalin-fixed paraffin-embedded (FFPE) specimens from patients who underwent lung tumor resection surgery at Affiliated Hospital of Nantong University from January 2021 to January 2023. Based on the pathological classification of the tumors, patients were divided into three groups: a benign tumor/adenocarcinoma in situ (BT/AIS) group, a minimally invasive adenocarcinoma (MIA) group, and an invasive adenocarcinoma (IA) group. The methylation levels of SHOX2 and RASSF1A in FFPE specimens were measured using the LungMe kit through methylation-specific PCR (MS-PCR). Using the methylation levels of SHOX2 and RASSF1A as predictive variables, various machine learning algorithms (including logistic regression, XGBoost, random forest, and naive Bayes) were employed to predict different lung adenocarcinoma pathological types. ResultsA total of 272 patients were included. The average ages of patients in the BT/AIS, MIA, and IA groups were 57.97, 61.31, and 63.84 years, respectively. The proportions of female patients were 55.38%, 61.11%, and 61.36%, respectively. In the early-stage lung adenocarcinoma prediction model established based on SHOX2 and RASSF1A methylation levels, the random forest and XGBoost models performed well in predicting each pathological type. The C-statistics of the random forest model for the BT/AIS, MIA, and IA groups were 0.71, 0.72, and 0.78, respectively. The C-statistics of the XGBoost model for the BT/AIS, MIA, and IA groups were 0.70, 0.75, and 0.77, respectively. The naive Bayes model only showed robust performance in the IA group, with a C-statistic of 0.73, indicating some predictive ability. The logistic regression model performed the worst among all groups, showing no predictive ability for any group. Through decision curve analysis, the random forest model demonstrated higher net benefit in predicting BT/AIS and MIA pathological types, indicating its potential value in clinical application. ConclusionMachine learning algorithms based on SHOX2 and RASSF1A methylation levels have high accuracy in predicting early-stage lung adenocarcinoma pathological types.