The Role of Epstein-Barr Virus (EBV) Infected Gastric Cancer in Increasing microRNA124 (miR-124) Promoter Methylation and Enhancer of Zeste Homolog 2 (EZH2) Gene Expression.

The tumor suppressor microRNAs, miR-21, miR-124, and miR-494, participate in the controlling several cellular processes. To assess target miRNAs promoter methylation levels, we investigated 304 pairs of gastric cancer (GC) tissues and non-tumor tissues. We used a commercial real-time polymerase chain reaction (RT-PCR) for Epstein-Barr virus (EBV) and Helicobacter pylori kit to detect EBV and H. pylori DNA in GC tissues. After finding hypermethylation in the promoter of the miR-124 gene, we evaluated its expression level using quantitative PCR (qPCR). Bioinformatics analysis confirmed miR-124 as a target of enhancer of Zeste homolog 2 (EZH2). Additionally, qPCR confirmed the association between EZH2 and miR-124. EBV and H. pylori DNA were detected in 9.5% and 15.1% of GC patients, respectively. Our findings also revealed significant differences in the miR-124 methylation levels among EBV-infected GC patients, H. pylori infected GC patients, GC patients without EBV and H. pylori infection, and non-tumor tissue. Bioinformatics and qPCR assays suggested an inverse relationship between the expression levels of EZH2 and miR-124 in EBV-infected GC patients. Our data revealed hypermethylation of the miR-124 promoter and significant reduction in its expression in EBV-infected GC tissues. It is possible that miR-124 may target EZH2 by binding to the 3'-UTR of the EZH2 gene, thus potentially contributing to the development of EBV-infected GC.

Prevalence of HIV, hepatitis B virus, hepatitis C virus, drug use, and sexual behaviors among street children in Iran: A systematic review and meta-analysis.

Background and Aims: Street children face a disproportionately higher risk of human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) due to high-risk sexual and drug use practices. We aimed to estimate the prevalence of these infections and related risk behaviors among street children in Iran. Methods: We searched PubMed, Web of Science (ISI), Embase, Scopus, and Google Scholar for the English-language records and Iranian databases, including SID, Magiran, and IRANDOC for the Farsi-language records up to September 18, 2022. Random effects analysis was used to obtain prevalence estimates for each condition. Homogeneity across included studies was assessed using I 2. Results: We extracted data from 18 eligible studies, representing 5646 children (83.2% boys), with a mean age of 10.2 (range: 5-18). The prevalence of HIV, HBV, and HCV were 0.79% (95% confidence intervals [CIs]: 0.0-5.56), 1.97% (95% CI: 1.01-3.19), and 1.88% (95% CI: 0.74-3.46), respectively. The prevalence of lifetime drug use and sexual abuse was 8.32% (95% CI: 4.83-12.62) and 10.18% (95% CI: 3.02-20.67) among street children, respectively. Conclusion: The estimated prevalence of HIV, HBV, and HCV among street children in Iran was higher than the estimates in the general population. Moreover, drug use and the experience of sexual abuse were prevalent among this population. These findings suggest the need for targeted prevention programs for street children in Iran.