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

• Published in: Medicine (Baltimore) 2024-03, Vol.103 (12), p.e36534-e36534
• Main Authors: Ghoreshi, Zohreh-Al-Sadat, Rezaei Zadeh Rukerd, Mohammad, Askarpour, Hedyeh, Kheirkhah Vakilabad, Ali Asghar, Nakhaie, Mohsen, Abbaszadeh Afshar, Mohammad Javad, Behboudi, Emad, Charostad, Javad, Arefinia, Nasir
• Format: Article
• Language: English
• Subjects: DNA; DNA Methylation; Enhancer of Zeste Homolog 2 Protein - genetics; Epstein-Barr Virus Infections - complications; Epstein-Barr Virus Infections - genetics; Epstein-Barr Virus Infections - pathology; Gene Expression; Herpesvirus 4, Human - genetics; Humans; MicroRNAs - genetics; Observational Study; Stomach Neoplasms - pathology
• ISSN: 0025-7974; 1536-5964
• DOI: 10.1097/MD.0000000000036534

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.