Anti-miRNA Antisense Oligonucleotides Technology

Abstract

One of the indispensable approaches in miRNA research as well as in miRNA therapy is inhibition or loss-of-function of miRNAs. Multiple steps in pathway for miRNA biogenesis could be targeted for inhibition of miRNA production and maturation. Thus far, nonetheless, the anti-miRNA antisense inhibitor oligoribonucleotides (AMO) technology used to target mature miRNAs has found most value for these applications. Standard AMO is a single-stranded 2′-O-methyl (2′-OMe)-modified oligoribonucleotide fragment exactly antisense to its target miRNA. The AMO technology was initially established in 2004 by Tuschl's laboratory (Laboratory of RNA Molecular Biology, The Rockefeller University) [Meister G, Landthaler M, Dorsett Y, Tuschl T, RNA 10:544–550, 2004] and by Zamore's laboratory (Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School) [Hutvagner G, Simard MJ, Mello CC, Zamore PD, PLoS Biol 2:465–475, 2004]. The idea was however originated from Boutla et al. (Nucleic Acids Res 31:4973–4980, 2003) who used antisense 2′-deoxyoligonucleotides to sequence-specifically inactivate miRNAs in microinjected D. melanogaster embryos. Since then, AMO technology has undergone many important modifications to enhance the efficiency and specificity of miRNA interference. These include cholesterol moiety-conjugated 2′-OMe modified AMOs called antagomiR [Krutzfeldt J, Rajewsky N, Braich R, Rajeev KG, Tuschl T, Manoharan M, Stoffel M, Nature 438:685–689, 2005], locked nucleic acid (LNA)-modified AMOs [Orom UA, Kauppinen S, Lund AH, Gene 372:137–141, 2006; Davis S, Lollo B, Freier S, Esau C, Nucleic Acids Res 34:2294–2304, 2006], 2′-O-methoxyethyl (2′-MOE) [Esau C, Davis S, Murray SF, Yu XX, Pandey SK, Pear M, Watts L, Booten SL, Graham M, McKay R, Subramaniam A, Propp S, Lollo BA, Freier S, Bennett CF, Bhanot S, Monia BP, Cell Metab 3:87–98, 2006; Davis S, Lollo B, Freier S, Esau C, Nucleic Acids Res 34:2294–2304, 2006], 2′-flouro (2′-F) (Davis et al. 2006), phosphorothioate backbone modification and peptide nucleic acid (PNA)-modified AMOs [Fabani MM, Gait MJ, RNA 14:336–346, 2008]. The AMO technology belongs to the “targeting-miRNA” and “miRNA-loss-of-function” strategy. For the sake of clarity and convenience, I here designate all different types of anti-miRNA antisense AMO and the conventional anti-mRNA antisense ASO, though ASO has also been used to refer to anti-miRNA antisense by some authors.