An overview of viral and nonviral delivery systems for microRNA

MicroRNAs (miRNAs) are small endogenous noncoding RNAs that direct posttranscriptional regulation of gene expression. Mature miRNAs function as components of RNA-induced silencing complex and interact directly with the 3’-untranslated region of the target mRNA. The target mRNA is then cleaved when the full complementarity of miRNA-mRNA is achieved. For partial complementarity, the translation of the target mRNA is repressed. It has been estimated that about one-third of human genes are regulated by miRNAs.[1] Deregulation of miRNAs has been found in many diseases including cancer, neurologic disease, metabolic disorders, and cardiovascular disease.