Identification of Dysregulated microRNAs in Glioma Using RNA-sequencing

Glioma is the most common malignant brain tumor in central nervous system. Despite advances in the treatment of glioma such as surgery and chemoradiotherapy, most patients are easy to relapse, resulting in adverse clinical outcomes. Hence, effective molecular-targeting treatment may be one of attractive strategies for glioma therapy. The dysregulated microRNAs (miRNAs), one of the candidates of therapeutic targets, are believed to play an important role in the progression of glioma. In this study, we aimed to examine the expression profile of miRNAs in glioma and provide a reference for glioma therapy. Firstly, expression profile of miRNAs in 5 normal brain tissues, 5 low-grade glioma (LGG) tissues and 5 glioblastoma (GBM) tissues was detected by RNA sequencing (RNA-seq). Next, the target genes of differentially expressed miRNAs (DEmiRNAs) were predicted and then GO enrichment and KEGG pathway analysis performed by bioinformatics. Finally, 10 miRNAs which were significantly up- or down-regulated both in GBM and LGG were validated by real-time quantitative PCR (qRT-PCR). RNA-seq results indicated a number of DEmiRNAs in glioma. There were 64 up-regulated miRNAs and 17 down-regulated miRNAs in LGG, and 181 up-regulated miRNAs and 124 down-regulated miRNAs in GBM, respectively. Bioinformatics analysis showed that the target genes of these DEmiRNAs were enriched in various biological processes and signaling pathways such as cell metabolic and developmental process. Selected DEmiRNAs were further confirmed by qRT-PCR. miRNA-10b-5p, miRNA-92b-3p and miRNA-455-5p were significantly up-regulated in both GBM and LGG; while miRNA-542-3p was significantly up-regulated in LGG; miRNA-184 and miRNA-206 were significantly down-regulated in both GBM and LGG; miRNA-766-5p and miRNA-1-3p were significantly down-regulated in GBM. The subject of our study demonstrated several dysregulated miRNAs may serve as a potential therapeutic target for glioma.