Diagnostic and Prognostic Potential of Serum Cell-Free microRNA-214 in Glioma

Objective We aimed to expound feasibility of serum cell-free microRNA-214 (miR-214) as a noninvasive biomarker for glioma in this study. Patients and Methods We detected expression of miR-214 in medium from 2 glioma cell lines to confirm whether it is secretory in screening phase. Then, we verified cell-free miR-214 expression in serum samples from an independent set of 100 preoperative patients with glioma, 30 matching postoperative patients, and 100 healthy controls. Results MiR-214 was secreted from glioma cell lines. Extracellular miR-214 levels were significantly overexpressed in preoperative serum from glioma patients with glioma, whereas its expression significantly decreased in matched postoperative serum. Upregulated cell-free miR-214 in serum was significantly associated with higher tumor grade, absence of isocitrate dehydrogenase, and unmethylated methylguanine methyltransferase promoter. Extracellular miR-214 in serum could effectively distinguish patients with glioma from healthy control (area under the curve = 0.885; 95% confidence interval, 0.833–0.926). Moreover, serum cell-free miR-214 was an independent prognostic indicator of overall survival for patients with glioma. Conclusions Serum cell-free miR-214 could serve as a promising noninvasive biomarker of glioma in tumor stratification, early diagnosis, and prognostic evaluation.