MicroRNA processing, role of GW182 Scaffolding proteins in RNA interference and Potential roles of let-7, miR-15 and miR-29 families as tumor suppressors

MicroRNAs are class of non-coding RNAs which are involved in many fundamental cellular and physiological process such as cell differentiation, proliferation and regulation of cell cycle and apoptosis. The vast majority of microRNAs are transcribed from non-coding regions (introns) of genes into primary miRNAs, which are then processed into precursor miRNAs and, lastly, microRNAs. Humans have at least 277 genes that are making microRNAs and these are conserved in mammals. MicroRNAs control gene expression by the sequence-specific targeting of mRNAs, which results in translational repression or mRNA destruction. Recent research has revealed that miRNAs have a role in tumor development, progression, and metastasis. MiRNA function dysregulation is linked to a growing variety of human disorders, including cancer, with miRNAs serving as tumor suppressors or oncogenes (oncomiRs). This review attempts to offer a snapshot of aspects of miRNA biogenesis, processing, role of GW182 scaffold proteins in microRNA mediated gene silencing and potential role of some microRNA families as tumor suppressors.