MiR-21: A key player in glioblastoma pathogenesis.

Glioblastoma multiform (GBM) is one of common cancers worldwide which has high rate among various populations. Despite serious efforts worldwide, GBM remains a deadly disease which is associated with poor prognosis. Multiple lines evidence indicated that deregulation of a variety of cellular and molecular pathways are related with GBM pathogenesis. Among of various targets involved in GBM pathogenesis, microRNAs (miRNAs) have been emerged as targets which deregulation of them are related with various stages of GBM. These molecules are small non-coding RNAs which could affect on a variety of cellular and molecular pathways involved in GBM. It has been showed that deregulation of them are associated with initiation and progression of GBM. MiR-21 is one of important miRNAs involved in GBM pathogenesis. A large number studies indicated that this miRNA could affect on a variety of cellular and molecular pathways such as insulin-like growth factor (IGF)-binding protein-3 (IGFBP3), RECK, and TIMP3. Exosomes are one of important players in GBM pathogenesis. Among of various exosomes, exosomal miR-21 may has key roles in GBM pathogenesis. These findings indicated that miR-21 has critical roles in GBM pathogenesis and could be used as diagnostic and therapeutic biomarkers for GBM patients. Here, we summarized the roles of miR-21 and exosomal miR-21 in GBM pathogenesis. Moreover, we highlighted utilization of miR-21 as diagnostic and therapeutic biomarker for GBM patients.