Davis Scott, Propp Stephanie, Freier Susan M, Jones Laura E, Serra Martin J, Kinberger Garth, Bhat Balkrishen, Swayze Eric E, Bennett C Frank, Esau Christine
Regulus Therapeutics, Carlsbad, CA 92008, USA.
Nucleic Acids Res. 2009 Jan;37(1):70-7. doi: 10.1093/nar/gkn904. Epub 2008 Nov 16.
Chemically modified antisense oligonucleotides (ASOs) are widely used as a tool to functionalize microRNAs (miRNAs). Reduction of miRNA level after ASO inhibition is commonly reported to show efficacy. Whether this is the most relevant endpoint for measuring miRNA inhibition has not been adequately addressed in the field although it has important implications for evaluating miRNA targeting studies. Using a novel approach to quantitate miRNA levels in the presence of excess ASO, we have discovered that the outcome of miRNA inhibition can vary depending on the chemical modification of the ASO. Although some miRNA inhibitors cause a decrease in mature miRNA levels, we have identified a novel 2'-fluoro/2'-methoxyethyl modified ASO motif with dramatically improved in vivo potency which does not. These studies show there are multiple mechanisms of miRNA inhibition by ASOs and that evaluation of secondary endpoints is crucial for interpreting miRNA inhibition studies.
化学修饰的反义寡核苷酸（ASO）被广泛用作使微小RNA（miRNA）功能化的工具。ASO抑制后miRNA水平的降低通常被报道显示出疗效。尽管这对评估miRNA靶向研究具有重要意义，但该领域尚未充分探讨这是否是衡量miRNA抑制的最相关终点。通过一种在存在过量ASO的情况下定量miRNA水平的新方法，我们发现miRNA抑制的结果可能因ASO的化学修饰而异。虽然一些miRNA抑制剂会导致成熟miRNA水平降低，但我们已经鉴定出一种新型的2'-氟/2'-甲氧基乙基修饰的ASO基序，其体内效力显著提高，但不会导致成熟miRNA水平降低。这些研究表明，ASO对miRNA的抑制存在多种机制，并且评估次要终点对于解释miRNA抑制研究至关重要。
