microRNA

microRNAs are a recently described class of short ribonucleic acids of 22-27 nucleotides in length, implicated in the regulation of hundreds of genes and an area of increasing interest in glioma research.

microRNAs are processed in the nucleus by Drosha then exported out into the cytoplasm by exportin-5. The hairpin of the miRNA is then cleaved off by Dicer. microRNAs are unwound to produce single-stranded RNA, which are loaded onto the RNA-induced silencing complex (RISC). RISC facilitates recognition of complementary strands of RNA in the cell, which are then cleaved, inhibiting translation of these mRNAs into proteins.

The use of microarrays has enabled the large-scale identification of miRNAs altered in pathological states. Studies to date have identified significant alteration in the expression of microRNAs mir-21, mir-181 and mir-128 in glioblastomas. Further research into the role of miRNAs in this field may reveal novel diagnostic and therapeutic strategies in the treatment of malignant glioblastoma.