Concomitant microRNA-31 downregulation and radixin upregulation predicts advanced tumor progression and unfavorable prognosis in patients with gliomas.

Purpose: To clarify the clinical significance of microRNA-31 (miR-31) and radixin (RDX) in human glioma.

Methods: Quantitative real-time polymerase chain reaction (qRT-PCR) analysis was used to characterize the expression patterns of miR-31 and RDX mRNA in 108 glioma and 20 normal brain tissues. The associations of miR-31 and RDX mRNA expressions with clinicopathologic factors and prognosis of glioma patients were also statistically analyzed.

Results: The expression levels of miR-31 in glioma tissues were significantly lower than those in normal brain tissues (P<0.001), while RDX mRNA was significantly overexpressed in glioma tissues compared with normal brain tissues (P<0.001). There was a negative correlation between miR-31 and RDX mRNA expression in glioma tissues (r=-0.69, P=0.01). Additionally, concomitant miR-31 downregulation and RDX upregulation (miR-31-low/RDX-high) was significantly associated with advanced pathological grade (P=0.001) and low Karnofsky performance score (P=0.01). Moreover, Kaplan-Meier survival and Cox regression analyses showed that the glioma patients with miR-31-low/RDX-high expression had poorest overall survival (P<0.001) and conjoined expression of miR-31-low/RDX-high was an independent prognostic indicator of glioma (P=0.01). Furthermore, subgroup analyses showed that miR-31-low/RDX-high expression was significantly associated with poor overall survival in glioma patients with high pathological grades (for grade III-IV: P<0.001).

Conclusions: Our findings have implications concerning the importance of concomitant miR-31 downregulation and RDX upregulation in tumor progression and poor prognosis of patients with gliomas. A combined detection of miR-31/RDX expression may benefit us in predicting clinical outcomes of glioma patients with high pathological grades.