Identification of microRNA-205 as a potential prognostic indicator for human glioma

Altered microRNA-205 (miR-205) expression has been found in glioma tissue samples and cell lines; however, the clinical significance of this is unclear. The aim of this study was to confirm the miR-205 expression pattern in human glioma and to investigate its clinical relevance. Quantitative reverse-transcription polymerase chain reaction assays showed that miR-205 expression was significantly lower in glioma tissues than in non-neoplastic brain tissues (P<0.001). Statistical analysis revealed a significant correlation between low miR-205 expression and both high grade glioma (World Health Organization [WHO] criteria, P=0.008) and a low Karnofsky performance status score (P=0.02). Survival analysis demonstrated that the cumulative 5-year overall survival rate of patients with glioma in the high miR-205 expression group was significantly higher than that in the low miR-205 expression group (P<0.001). Multivariate Cox regression analysis further indicated that miR-205 expression (P=0.01) and WHO grade (P=0.01) were independent prognostic indicators of the overall survival of patients with glioma. Moreover, subgroup analyses revealed that the cumulative 5-year overall survival rate of patients with high grade (III-IV) glioma was significantly worse for the low miR-205 expression group than for the high miR-205 expression group (P<0.001), but no significant difference was found for patients with low grade (I-II) glioma (P=0.09). In conclusion, down-regulation of miR-205 was associated with glioma progression. Our data are the first to suggest that miR-205 holds potential as a prognostic factor for glioma, especially for patients with advanced disease.