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. Deregulation of miRNAs has been found in many diseases including cancer, neurologic disease, metabolic disorders, and cardiovascular disease.
Due to the important function of miRNAs, miRNA therapy has attracted significant attention. miRNA therapy could be categorized into two mechanisms, according to deregulation status of the target mRNA: miRNA replacement therapy that restores the miRNA expression by transduction of exogenous miRNA, and miRNA inhibition therapy that inhibits the miRNA expression by designing anti-miRNA oligonucleotides known as antagomirs.[2,3] Currently, both viral and nonviral miRNA delivery systems are used, and there are advantages and disadvantages for each approach. Read more...