THE RISING WORLD OF MICRORNAS:ONCOGENES AND TUMOR SUPPRESSORS IN CANCER

Abstract

The sequencing of the human genome has revealed that the bulk of the genome is transcribed into noncoding RNAs, including microRNAs. These microRNAs are deregulated in cancer where they regulate a wide array of functions associated with tumorigenesis. Glioblastoma (GBM) is the most common and aggressive primary intracranial tumor of the adult brain. miRNAs are short noncoding RNAs that broadly regulate gene expression. They exert their actions via transcriptional, post-transcriptional, and epigenetic mechanisms that are poorly understood. Numerous miRNAs are deregulated in GBM, where their expression levels can serve as biomarkers. They can act as either oncogenes or tumor suppressors in GBM by targeting the expression of numerous tumor-suppressors or oncogenes. miRNAs regulate all GBM malignancy aspects including cell proliferation, survival, motility, migration, invasion, angiogenesis, cancer stem cell biology, microenvironment modulation, immune escape, and therapy resistance. MiRNAs can also be secreted via exosomes or microvesicles in body .uids, where they can be used as diagnosis and/or prognosis biomarkers. Considering their deep involvement in GBM malignancy, numerous studies are currently undertaken to exploit miRNAs as therapeutic agents or targets. This short review summarizes the biogenesis, deregulation, functions, mechanisms of action, and clinical applications of miRNAs in GBM