miRNA Multiplayers in glioma. From bench to bedside

Glioblastoma multiforme (GBM) is the most common type of malignant gliomas, characterized by genetic instability, intratumoral histopathological variability and unpredictable clinical behavior. Disappointing results in the treatment of gliomas with surgery, radiation and chemotherapy have fuelled a search for a new therapeutic targets and treatment modalities. A novel small non-coding RNA molecules, microRNAs (miRNAs), appear to represent one of the most attractive target molecules contributing to the pathogenesis of various types of tumors. They play crucial roles in tumorigenesis, angiogenesis, invasion and apoptosis. Some miRNAs are also associated with clinical outcome and chemo- and radiotherapy resistance. Moreover, miRNA have the potential to affect the responses to molecular-targeted therapies and they also might be associated with cancer stem cell properties, affecting tumor maintenance and progression. The expression profiles of miRNAs are also useful for subclassification of GBM, what underscores the heterogeneity of diseases that all share the same WHO histopathological grade. Importantly, molecular subtypes of GBM appear to correlate with clinical phenotypes, tumor characteristic and treatment outcomes. miRNAs are then biological markers with possible diagnostic and prognostic potential. They could also serve as one of the promising treatment targets in human glioblastoma.