Decreased expression of microRNA-206 correlates with poor clinical outcome in patients with malignant astrocytomas

MicroRNA-206 (miR-206) has been proved to function as a tumor suppressor in several types of human malignant cancers. More recently, it has been demonstrated that the ectopic expression of miR-206 significantly inhibited the proliferation and promoted apoptosis at the early stages in glioma cell U343. In order to investigate the clinical significance of miR-206 expression in human astrocytoma, quantitative real-time polymerase chain reaction (qRT-PCR) analysis was used to characterize the expression patterns of miR-206 in 108 astrocytoma and 20 normal brain tissues. As the results, the expression levels of miR-206 in astrocytoma tissues were significantly lower than those in normal brain tissues (P < 0.001). Additionally, the decreased expression of miR-206 in astrocytoma was significantly associated with advanced pathological grade (P = 0.008), low Karnofsky performance score (KPS, P = 0.02), and large tumor size (P = 0.01). Moreover, Kaplan-Meier survival and Cox regression analyses showed that low miR-206 expression (P < 0.001) and advanced pathological grade (P = 0.02) were independent factors predicting poor prognosis for astrocytomas. In conclusion, this is the first report of the differential expression of miR-206 in human astrocytoma tissues. MiR-206 could be a valuable marker of astrocytoma progression and low miR-206 expression is associated with poor overall survival in patients with malignant astrocytomas.