Serum microRNA-210 as a potential noninvasive biomarker for the diagnosis and prognosis of glioma

Abstract

Background: MicroRNA-210 (miR-210) is an oncogenic miRNA previously associated with prognosis in human gliomas, an incurable tumour type of the central nervous system. Here miR-210 was investigated as a potential serum biomarker in the diagnosis and prognosis of glioma.

Methods: Serum was immediately prepared from blood samples collected from patients with glioma grades I-IV at primary diagnosis (n=136) and healthy controls (n=50) from February 2007 to March 2014 in the Department of Neurosurgery of the First Affiliated Hospital of Wannan Medical College (Wuhu, China). Total RNA was isolated from serum. cDNA was synthesised with primers specific for miR-210 and miR-16-1 (internal control), and quantitative real-time RT-PCR was performed. Results were statistically analysed to determine the role of miR-210 in the diagnosis and prognosis of human glioma patients.

Results: An approximately seven-fold increase in miR-210 expression was detected in serum samples from glioblastoma patients relative to healthy controls. A threshold expression value (2.259) was chosen from receiver operator characteristic curves (ROC), and the low and high miR-210 expression groups were analysed by multivariate Cox proportional hazard regression and Kaplan-Meier analyses. Results revealed an association of high serum miR-210 expression with tumour grade and poor patient outcome (P-values <0.001).

Conclusions: Serum miR-210 is a promising diagnostic and prognostic biomarker that can be detected in the peripheral blood of patients with glioma.

Figure 1

MiR-210 is increased in serum from glioblastoma patients relative to healthy controls. Initial screening for miR-210 expression in the training phase, using a small subset of serum specimens from glioma patients. Box plots are shown for miR-210 levels in serum from normal control subjects (n=10) and glioblastoma patients (n=10). Boxes represent interquartile range, and the horizontal line across each box represents the median value. The y axis (log10 scale) represents relative expression of miR-210 where the data were normalised to miR-16-1 expression in sera. Statistical analysis was performed using Mann–Whitney U tests. ***P<0.001.

Figure 2

Increased expression of miR-210 in serum samples from gliomas. (A) Box plots represent serum miR-210 levels in healthy control subjects (Normal; n=40), all patients with astrocytic gliomas (Glioma; n=126), and patients separated based on histological WHO grades I–V (PA, n=13; DA, n=35; AA, n=46; GBM, n=32). The y axis (log10 scale) represents miR-210 expression normalised to miR-16-1. Boxes represent the interquartile range, and the horizontal line across each box represents the median value. Statistically significant differences were determined using the Mann–Whitney U test and the Kruskal–Wallis test. (B) ROC curve analysis based on serum miR-210 levels for distinguishing glioma patients from normal controls. Serum miR-210 yielded an area under the curve (AUC) value of 0.927 (95% confidence interval=0.889–0.964), with 91.27% sensitivity and 72.50% specificity in distinguishing glioma patients from normal controls.

Figure 3

Kaplan–Meier curves for overall survival based on pathological diagnosis of the primary tumour and miR-210 expression in matched serum samples. Kaplan–Meier curves displaying overall survival of (A) patients with high-grade (n=78) vs low-grade tumours (n=48; P<0.001), and (B) patients with high-serum (n=94) vs low-serum miR-210 expression (n=32; P<0.001).