The role of microRNAs in medulloblastoma

Medulloblastomas (MBs) are the most frequent brain tumors in children and remained a major therapeutic challenge. Clinical and histopathological features are used for disease classification and patient prognostication. Currently, several molecular studies using transcriptomic and genomic approaches suggested the existence of four molecular subtypes, increasing the complexity, and knowledge of MB biology. Despite these significant advances, the molecular basis of MBs is not fully understood. MicroRNAs (miRNAs) are a group of small nonprotein coding RNA molecules that target genes by inducing mRNA degradation or translational repression. They represent an evolutionary conserved mechanism that controls fundamental cellular processes, such as development, differentiation, metabolism, proliferation, and apoptosis. Aberrant expression of miRNAs correlates with various cancers. This altered expression can arise from mutation, methylation, deletion, and gain of miRNA-encoding regions. We here review the knowledge of miRNAs in MBs. The expression patterns of miRNAs in MBs were comprehensively evaluated and their diagnostic, prognostic, and therapeutic biomarker role assessed. miRNAs are important players in MB tumorigenesis and their therapeutic exploitation can constitute an alternative approach to this devastating disease.