MicroRNAs are 21-25 nucleotide small, non-coding RNAs that post-transcriptionally repress the expression of protein- coding genes through binding to the 3' untranslated regions

MicroRNAs (miRNAs) are frequently dysregulated in glioblastoma (GBM) patients. It has been discovered that highly stable extracellular miRNAs circulate in the blood of both healthy individuals and patients. miRNAs in serum of patients with GBM and normal controls were analyzed by microarray analysis. The relevant bioinformatic analysis of the predicted target genes (gene ontology, pathway, gene network analysis) were performed. The miRNA microarray reveals differentially expressed miRNAs in serum between the GBM and normal controls. Of the 752 miRNAs, 115 miRNAs were upregulated in the GBM group, and 24 miRNAs were downregulated (fold change ≥2.0, P<0.01). By further analysis, we found that miR-576-5p, miR-340 and miR-626 were significantly overexpressed, but miR-320, let-7g-5p and miR-7-5P showed significantly low expression in GBM patients. By further bioinformatic analysis, we found that they possibly play important roles in the regulation of glioma signaling pathways. In summary, the six miRNAs are significant distinct in the peripheral blood of patients with GBM pathologies. These data suggest that the miRNA profile of the peripheral blood may serve as a new biomarker for glioma diagnosis with high specificity and sensitivity.