Abstract
MicroRNAs (miRs) transferred by exosomes can function as non-invasive potential biomarkers for the diagnosis and prognosis in various types of cancer. The present study examined the diagnostic and prognostic value of serum exosomal-(exo-)miR-210 levels in association with hypoxic conditions in patients with glioma. Serum levels of exo-miR-210 were determined by quantitative PCR in samples obtained from patients with glioma. Patients were divided into low-and high-expression exo-miR-210 groups according to the median expression value. Statistical analyses were conducted to examine the potential value of exo-miR-210 in predicting the diagnosis and prognosis of patients with glioma. A significant increase in serum exo-miR-210 levels was observed in patients with glioma compared with healthy controls. Additionally, the expression levels of exo-miR-210 were increased with ascending pathological grades. Furthermore, expression levels of miR-210 in serum exosomes from patients with glioblastoma were markedly decreased following surgery and upregulated once more at the recurrences of primary tumors, indicating that exo-miR-210 could reflect alterations in malignant glioma loads. In addition, Kaplan-Meier analysis was performed to analyze overall survival (OS) time. Patients with malignant glioma with high exo-miR-210 expression exhibited a poorer OS compared with patients with low expression. Importantly, univariate and multivariate Cox regression analysis revealed that the expression levels of exo-miR-210 in glioma serum samples were independently associated with OS. Finally, increased serum exo-miR-210 expression was positively associated with high levels of hypoxia-inducible factor 1a and reflected hypoxia in patients with glioma. In conclusion, serum levels of exo-miR-210 may serve as a diagnostic, prognostic and hypoxic biomarker to reflect glioma status and hypoxic signatures.