A direct comparison of anti-microRNA oligonucleotide potency.
OBJECTIVE
Cataloguing endogenous miRNA targets by inhibiting miRNA function is fundamental to understanding the biological importance of each miRNA in gene regulatory pathways. Methods to down-regulate miRNA activity may help treat diseases where over-expression of miRNAs relates to the underlying pathophysiology. This study objectively evaluates the in vitro potency of different anti-miRNA oligonucleotides (AMOs) using various design and modification strategies described in the literature as well as some novel modification strategies.


METHODS
MiR21 and miR16 AMOs, containing chemical modifications such as 2'-O-methyl RNA, locked nucleic acid and 2'-Fluoro bases with or without phosphorothioate linkages, were directly compared by transfection into HeLa cells using a dual-luciferase reporter assay to quantify miRNA inhibition.


RESULTS
Potency for the various AMOs ranged from inactive at high dose (50 nM) to strongly inhibitory at both high and low dose (1 nM). Including phosphorothioate linkages improved nuclease stability and generally increased functional potency.


CONCLUSIONS
Incorporating high binding affinity modifications, such as LNA and 2'F bases, increases AMO potency while maintaining specificity; nevertheless, use of low dose is preferred when using high potency reagents to minimize the potential for cross reactivity. 2'OMe/LNA chimeras with PS modifications were the most potent constructs tested for miRNA inhibition in vitro.
Lennox
Kim A
KA
Integrated DNA Technologies, 1710 Commercial Park, Coralville, Iowa 52241, USA. klennox@idtdna.com
Behlke
Mark A
MA
D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D018929:Cell Culture Techniques; D002851:Chromatography, High Pressure Liquid; D004795:Enzyme Stability; D006367:HeLa Cells; D006801:Humans; D049409:Luciferases, Firefly / Q000235:genetics; D049410:Luciferases, Renilla / Q000235:genetics; D008297:Male; D051379:Mice; D035683:MicroRNAs / Q000037:antagonists & inhibitors* / Q000235:genetics; D008969:Molecular Sequence Data; D016376:Oligonucleotides, Antisense / Q000737:chemistry / Q000235:genetics / Q000494:pharmacology*; D010957:Plasmids; D012260:Ribonucleases / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization; D014162:Transfection
D035683:MicroRNAs; D016376:Oligonucleotides, Antisense; D049410:Luciferases, Renilla; D049409:Luciferases, Firefly; D012260:Ribonucleases