Differential expression of microRNA-210 in gliomas of variable cell origin and correlation between increased expression levels and disease progression in astrocytic tumours.

INTRODUCTION The microRNA, miR-210, is frequently associated with hypoxia induction, and an increase in its levels is often correlated with poor prognosis in many solid tumours. The present study examines the levels of miR-210 in glioma tumours of multiple origins to determine if an association can be established with disease progression. MATERIAL AND METHODS Tissue samples were acquired from normal brain tissue, oligodendroglial tumours and astrocytic tumours. The astrocytic tumours were further divided by grade: diffuse astrocytomas (WHO grade II), anaplastic astrocytomas (WHO grade III), and glioblastoma (WHO grade IV). The expression of miR-210 was examined by real-time quantitative RT-PCR. The correlation of the expression of miR-210 and astrocytic tumour grade was analyzed by the Spearman correlation test. RESULTS MiR-210 presents a differential expression depending on the origin of the glioma. Oligodendroglial tumours exhibit a significantly reduced level of miR-210 as compared with normal brain tissue. In contrast, astrocytic tumours demonstrate significantly increased levels of miR-210. Furthermore, the expression of miR-210 is positively correlated with the grade of astrocytic tumour, in the following order: grade IV > grade III > grade II > normal brain tissue (p < 0.05). CONCLUSIONS MiR-210 levels can be potentially established as a biomarker for pathological diagnosis of malignant astrocytic tumour progression. In addition, the expression of miR-210 can be utilized as an additional identification measure of glioma tumour origin.