Department of Life Science, Faculty of Pharmacy, Yasuda Women's University, Hiroshima, Japan.
Mol Pharm. 2012 May 7;9(5):1374-83. doi: 10.1021/mp2006278. Epub 2012 Apr 24.
Short interfering RNAs (siRNAs), used in RNA interference (RNAi) technology, are powerful tools for target-gene silencing in a sequence-specific manner. In this study, Dicer-substrate 27-nucleotide (nt) double-stranded RNAs (dsRNAs), which are known to have a highly potent RNAi effect, were conjugated with palmitic acid at the 5'-end of the sense strand to enhance intracellular delivery and RNAi efficacy. The palmitic acid-conjugated 27-nt dsRNAs (C16-ds27RNAs) were prepared by our simple synthesis strategy in good yield. The C16-ds27RNAs were cleaved by a Dicer enzyme, leading to the release of 21-nt siRNAs. The high level of stability in serum using C16-ds27RNAs was also confirmed. The C16-ds27RNAs showed enhanced RNAi potency targeted to both an exogenous luciferase and an endogenous vascular endothelial growth factor (VEGF) gene in the presence or absence of a transfection reagent, such as Lipofectamine 2000. In addition, the C16-ds27RNAs had a more potent gene-silencing activity than the other lipid-conjugated 21-nt siRNAs and 27-nt dsRNAs. The C16-ds27RNAs also exhibited significant membrane permeability. These results suggested that the C16-ds27RNAs will be useful for next-generation RNAi molecules that can address the problems of RNAi technology.
短干扰 RNA（siRNA）在 RNA 干扰（RNAi）技术中被用于以序列特异性方式沉默靶基因。在这项研究中，双链 RNA（dsRNA）在 Dicer 底物 27 个核苷酸（nt）处与棕榈酸在正义链的 5' 端连接，以增强细胞内递呈和 RNAi 效果。棕榈酸偶联的 27nt dsRNA（C16-ds27RNAs）是通过我们的简单合成策略以良好的产率制备的。C16-ds27RNAs 被一种 Dicer 酶切割，导致释放出 21nt siRNA。在血清中使用 C16-ds27RNAs 时也证实了其具有很高的稳定性。在存在或不存在转染试剂（如 Lipofectamine 2000）的情况下，C16-ds27RNAs 对外源荧光素酶和内源性血管内皮生长因子（VEGF）基因均表现出增强的 RNAi 效力。此外，C16-ds27RNAs 比其他脂质偶联的 21nt siRNA 和 27nt dsRNA 具有更强的基因沉默活性。C16-ds27RNAs 还表现出显著的膜通透性。这些结果表明，C16-ds27RNAs 将成为下一代 RNAi 分子的有用工具，可解决 RNAi 技术的问题。
