Overexpression of microRNA-155 predicts poor prognosis in glioma patients

MicroRNA-155 is highly expressed in many malignant tumors with poor prognosis, which regulates cell apoptosis, proliferation, invasion, metastasis, tumor angiogenesis, and metabolism. This study aims at investigating the clinical significance of miR-155 expression in human gliomas. Real-time quantitative PCR was used to detect the expression levels of miR-155 in 131 glioma and 16 normal brain tissues. The association of miR-155 expression with clinicopathological factors and prognosis of glioma patients were analyzed. The expression levels of miR-155 were significantly higher in glioma tissues than that in normal brain tissues (P < 0.001), which was associated with high pathological grade (P < 0.001) and low Karnofsky Performance Status score (P = 0.022). As a result of Kaplan-Meier survival and Cox regression analyses, overall survival (OS) rates and progression-free survival were significantly poorer in high-expression group relative to low-expression group (both P < 0.001). Furthermore, miR-155 expression was significantly associated with poor OS (P < 0.001) and PFS (P = 0.001) in glioma patients who had high pathological grades (III-IV) as calculated by subgroup analyses. These findings reveal that miR-155 expression might be an independent prognostic factor and a therapeutic target for human glioma.