P65DEREGULATED MICRORNAS IN SERUM AS BIOMARKERS FOR GLIOMA

INTRODUCTION: Gliomas, including glioblastoma, release both microvesicles containing microRNA (miRNA) and miRNA-protein complexes which can be isolated from biological fluids such as serum. Circulating miRNA can be used as biomarkers for earlier diagnosis, predicting response to treatment and for prognostic information. The aim of this study was to identify a panel of circulating miRNA biomarkers for glioma. METHOD: MiRNAs were isolated from the sera of GBM (n = 26) and control patients (n = 23), using phenol-chloroform extraction. The relative expression of 84 miRNAs was determined using qRT-PCR. 26 miRNAs were selected for further analysis and a final panel of three miRNAs were analysed in a larger patient set. Data were normalised using a synthetic spike-in and analysed using the delta Ct method. Statistical significance was determined using a Mann-Whitney t-test and one way ANOVA with a Bonferroni post-hoc test, a p-value <0.05 was considered significant. RESULTS: Three miRNAs were differentially expressed in the sera of GBM patients compared to controls. MiRNA-X was significantly up-regulated in the sera of a subset of GBM patients,these individuals exhibited an increased survival time compared to those with no up-regulation in miRNA-X shown by Kaplan-Meier survival analysis. MiRNA-Y was found to be significantly down-regulated in the sera of male GBM patients. MiRNA-Z was significantly up-regulated in the sera of GBM patients over the age of 60 compared to age matched controls. CONCLUSION: In summary, we have identified three miRNAs that could be used as a diagnostic panel for GBM. Further investigation will determine their role in glioblastoma and validate their use as biomarkers.