Oncogenic role of microRNAs in brain tumors

Abstract

MicroRNAs (miRNAs) are short non-protein-coding RNAs that function as key regulators of diverse biological processes through negative control on gene expression at the post-transcriptional level. Emerging evidence indicates that miRNAs play an important role in the development of human cancers, with their deregulation resulting in altered activity of downstream tumor suppressors, oncogenes and other signaling molecules. Recent years have seen considerable progress in miRNA research in brain tumors, particularly in glioblastomas and medulloblastomas, providing novel insights into the pathogenesis of these malignant lesions. Expression profiling has unveiled miRNA signatures that not only distinguish brain tumors from normal tissues, but can also differentiate histotypes or molecular subtypes with altered genetic pathways. Moreover, specific miRNA subsets may have potential diagnostic and prognostic values in some brain tumors. Several deregulated miRNAs uncovered in glioblastomas and medulloblastomas have their gene targets and the associated genetic pathways identified. This review summarizes recent findings of miRNA study in brain tumors.

Host–virus interactions during hepatitis C virus infection: a complex and dynamic molecular biosystem

“…Probing the miRNA milieu has already facilitated the discovery of many oncogenes (reviewed in ref. [119][120][121][122]. Similar studies with regards to HCV have revealed valuable knowledge with regards to host-virus interactions.…”

The role of the PI3K/AKT/mTOR pathway in brain tumor metastasis

“…[111] In MB, miR-21 suppression inhibited tumor migration. [112] MiR-183 has a pro-tumorigenic effect in the MYC-driven MB subgroup through the inhibition of apoptosis, deregulation of the mTOR pathway and modulation of cell motility and migration. [113] During the EMT process, malignant cells start to intravasate into the surrounding blood vessels in order to migrate to other parts of the body.…”

The oncogenic RNA-binding protein Musashi1 is regulated by tumor suppressor miRNAs

“…Putative tumor suppressor miRNAs selected as candidates for Msi1 regulation includes miR-34a, miR-101, miR-128, miR-137 and miR-138. [30][31][32][33][34][35][36][37][38] A synopsis of their profiling studies, mRNA targets and impact on biological functions is summarized in Table 1. These miRNAs have decreased or no expression in brain tumors, as compared to normal brain tissue.…”