Selective Protection of Nuclease-Sensitive Sites in siRNA Prolongs Silencing Effect
Selective Protection of Nuclease-Sensitive Sites in siRNA Prolongs Silencing Effect
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DOI：
10.1089/oli.2008.0162
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发表时间：
2009-06-01
期刊：
影响因子：
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通讯作者：
Chernolovskaya, Elena L.
中科院分区：
文献类型：
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作者：
Volkov, Anton A.;Kruglova, Natal'ya S.;Chernolovskaya, Elena L.
小干扰 RNA (siRNA) 被认为是特定基因沉默的有效药物；然而，siRNA 的核酸酶敏感性限制了其生物医学应用。迄今为止，尚未开发出通用的方法来提高 siRNA 的核酸酶抗性，同时保持低毒性和高活性。在这项研究中，我们提出了一种对 siRNA 进行位点特异性修饰的算法，该算法基于在血清存在下对 siRNA 的核酸酶敏感位点进行定位，然后在确定的切割位置掺入核糖核苷酸的 2'-O-甲基类似物。我们发现，对核酸酶敏感位点的保护显着增强了 siRNA 的核酸酶抗性，并且仅略微降低了沉默效率。与相同序列的未修饰、部分修饰或随机修饰的 siRNA 相比，所有核酸酶敏感位点的修饰延长了 siRNA 沉默效应的持续时间。这项研究表明，核酸酶敏感位点的靶向化学修饰可以为疾病相关基因的控制提供高效的基于 siRNA 的治疗方法。
Small interfering RNAs (siRNAs) are considered as potent agents for specific gene silencing; however, nuclease sensitivity of siRNA limits their biomedical applications. Till date, no universal methodology has been developed to improve the nuclease resistance of siRNA, preserving low toxicity and high activity. In this study, we proposed an algorithm for the site-specific modification of siRNAs based on the mapping of their nuclease-sensitive sites in the presence of serum followed by the incorporation of 2'-O-methyl analogs of ribonucleotides at the identified positions of cleavage. We found that the protection of nuclease-sensitive sites considerably enhanced nuclease resistance of siRNA and only slightly reduced the efficiency of silencing. Modification of all nuclease-sensitive sites prolonged the duration of the silencing effect of the siRNA compared to nonmodified, partially modified, or randomly modified siRNA of the same sequence. This study showed that the targeted chemical modification of nuclease-sensitive sites could provide highly efficient siRNA-based therapeutics for the control of disease-related genes.