miR-512-3p as a Potential Biomarker of Poor Outcome in Pediatric Medulloblastoma.

The tumorigenesis of medulloblastoma (MB), the most frequent malignant brain tumor in children, is not completely known. MicroRNA (miRNA) expression profiles have been associated with human cancers; however, the role played by miRNAs in pediatric MB has been poorly explored. Global miRNA expression in MB and non-neoplastic cerebellum samples was evaluated by microarray assay. Nine miRNAs (miR-31-5p, -329, -383, -433, -485-3p, -485-5p, -491, -512-3p, and 539-5p) in 51 pediatric MB and 7 pediatric non-neoplastic cerebellum samples were chosen for validation by qRT-PCR. The validated miRNAs were less expressed in the MB samples than in the non-neoplastic controls. In our cohort of patients, higher miR-512-3p expression was associated with incomplete degree of resection, classification as high risk, classification as group 4, and poor overall survival. In silico analysis in an independent cohort of MB patients identified that some of the miR-512-3p target genes were also correlated with prognostic features. Our results have shown that miR-512-3p could be associated with poor clinical outcomes in pediatric MB, suggesting that miR-512-3p is a potential biomarker of prognosis.