Department of Microbiology and Immunology, Dodson Interdisciplinary Immunotherapy Institute and Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, Florida, USA.
Mol Ther Nucleic Acids. 2012 Oct 16;1(10):e51. doi: 10.1038/mtna.2012.41.
Oligonucleotide aptamer-mediated in vivo cell targeting of small interfering RNAs (siRNAs) is emerging as a useful approach to enhance the efficacy and reduce the adverse effects resulting from siRNA-mediated genetic interference. A current main impediment in aptamer-mediated siRNA targeting is that the activity of the siRNA is often compromised when conjugated to an aptamer, often requiring labor intensive and time consuming design and testing of multiple configurations to identify a conjugate in which the siRNA activity has not been significantly reduced. Here, we show that the thermal stability of the siRNA is an important parameter of siRNA activity in its conjugated form, and that siRNAs with lower melting temperature (T(m)) are not or are minimally affected when conjugated to the 3' end of 2'F-pyrimidine-modified aptamers. In addition, the configuration of the aptamer-siRNA conjugate retains activity comparable with the free siRNA duplex when the passenger strand is co-transcribed with the aptamer and 3' overhangs on the passenger strand are removed. The approach described in this paper significantly reduces the time and effort necessary to screening siRNA sequences that retain biological activity upon aptamer conjugation, facilitating the process of identifying candidate aptamer-siRNA conjugates suitable for in vivo testing.Molecular Therapy - Nucleic Acids (2012) 1, e51; doi:10.1038/mtna.2012.41; published online 16 October 2012.
寡核苷酸适体介导的小干扰 RNA（siRNA）体内细胞靶向作为增强功效和降低由 siRNA 介导的遗传干扰引起的不良反应的有用方法正在出现。适体介导的 siRNA 靶向的当前主要障碍是，当与适体缀合时，siRNA 的活性通常会受到损害，通常需要费力和耗时的设计和测试多个配置以鉴定其中 siRNA 活性未显著降低的缀合物。在这里，我们表明 siRNA 的热稳定性是其缀合形式中 siRNA 活性的重要参数，并且当与 2'-F-嘧啶修饰的适体的 3'末端缀合时，具有较低熔点（Tm）的 siRNA 不会或最小化受到影响。此外，当与适体共转录并且去除过客链上的 3'突出时，适体-siRNA 缀合物的构型保留与游离 siRNA 双链体相当的活性。本文中描述的方法大大减少了筛选在与适体缀合后保留生物活性的 siRNA 序列所需的时间和精力，从而促进了鉴定适合体内测试的候选适体-siRNA 缀合物的过程。分子治疗-核酸（2012 年）1，e51；doi:10.1038/mtna.2012.41；在线发表 2012 年 10 月 16 日。
