Comprehensive analysis of competitive endogenous RNA network in colorectal cancer

Background: Colorectal cancer (CRC) is a leading cause of cancer-related deaths worldwide. Growing evidence supports a role for noncoding RNAs (ncRNAs) in CRC. In particular, they form competitive endogenous RNA (ceRNA) networks involved in the regulation of mRNA expression. However, the role of these networks in the pathogenesis of CRC is not fully understood. The aim of this study was to elucidate the role of circRNA/lncRNA-miRNA-mRNA systems in CRC pathogenesis based on the construction of a ceRNA network. Methods: RNA expression profiles were obtained from public datasets in the Gene Expression Omnibus (GEO) database and used for further analysis by online databases and tools. Results: In total, 245 circRNAs, 1,666 lncRNAs, 5 miRNAs, and 934 mRNAs were differentially expressed in CRC samples. Functional enrichment analysis identified altered biological functions related to the mRNAs in the ceRNA network, and it was found that the oxytocin signaling pathway was significantly enriched (P<0.05) in genes with differential expression in CRC. Additionally, we established a protein-protein interaction (PPI) network and identified 10 hub genes for the construction of circRNA/lncRNA-miRNA-hub gene regulatory modules. Conclusions: We identified several ncRNAs with a possible pathogenetic role in CRC and built a CRC-specific ceRNA network. The results of our study provide novel insights into the molecular events implicated in CRC.