Identification of microRNA-181 as a promising biomarker for predicting the poor survival in colorectal cancer

Background A series of studies have investigated the vital role of microRNA-181 (miR-181) in the initiation and development of colorectal cancer (CRC), and demonstrated that it might be associated with the prognosis of CRC. However, inconsistent findings have hindered its clinical application. Methods A comprehensive meta-analysis and an integrative bioinformatics analysis were carried out for concluding current available evidence, clarifying the preliminary prognostic value and unfolding the underlying biological function of miR-181 in CRC patients. Results The findings revealed that elevated expression levels of miR-181 were associated with significantly poorer overall survival rates (HR = 1.75, 95% CI: 1.26-2.43, P < .05). Meanwhile, the target genes of miR-181 were identified and enriched into several important gene ontology (GO) categories and signaling pathways including miRNAs in cancer, pathways in cancer, proteoglycans in cancer, colorectal cancer, FoxO signaling pathway, PI3K-Akt signaling pathway, VEGF signaling pathway, HIF-1 signaling pathway, mTOR signaling pathway, and cAMP signaling pathway, which were confirmed highly involved in the initiation and progression of CRC. In addition, the protein-protein interaction (PPI) networks were set up by miR-181 targets to screen hub nodes and significant modules, which were also considerably associated with the molecular pathogenesis of CRC. Conclusions The present study demonstrated that miR-181 could be a promising biomarker with predictive value for prognosis for CRC patients. However, future studies comprising large cohorts from multicenter are warranted to further investigate the biomarker value of miR-181.