Enrichment of differentially expressed eRNAs in cancer-related pathways in gastric cancer

Introduction & Objectives: Enhancer RNAs (eRNAs) are a class of the non-coding RNAs that are involving in the regulation of gene transcription. Alterations in eRNAs expression has been reported in several cancer types. In the current study, we utilized eRic database to analyze the differentially expressed eRNAs in gastric cancer tissues from TCGA cohort to determine the molecular mechanisms involved in tumorigenesis.Materials & Methods: Differentially expressed eRNAs were selected based on their fold change and adjusted p-values, which were provided by the eRic database based on the data from gastric cancer samples of TCGA cohort. The inclusion criteria were set as follows: false discovery rate (FDR) < 0.05 and |log2(fold change)| > 1. To understand the biological meaning behind the large list of upregulated eRNAs, target genes of them were extracted and enrichment analysis was performed using Enrichr tool.Results: In total, 724 differentially expressed eRNAs (693 upregulated and 31 downregulated) were identified in gastric cancer in comparison with normal tissues. Then, we determined target genes of the upregulated eRNAs which were 859 genes. Our results revealed that these target genes were significantly enriched in various biological processes of Gene Ontology (GO) terms such as regulation of gene expression (GO: 0010468), regulation of mRNA processing (GO: 0050684), regulation of transcription from RNA polymerase II promoter (GO: 0006357) and associated with cellular components such as RNA polymerase II transcription factor complex (GO: 0090575), nuclear transcription factor complex (GO: 0044798) and nuclear chromatin (GO: 0000790). Pathway analysis showed that the genes were mainly involved in tumorigenesis-associated pathways such as Wnt Signaling Pathway, Gastric Cancer Network and EGF/EGFR Signaling Pathway.Conclusion: These findings increase our understanding of the molecular mechanisms of gastric cancer mediated by eRNAs and will aid in identifying potential targets for diagnostic and therapeutic usage.