title: Lipid-conjugated 27-nucleotide double-stranded RNAs with dicer-substrate potency enhance RNAi-mediated gene silencing.
abstract: 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.
authors.affiliation: Department of Life Science, Faculty of Pharmacy, Yasuda Women's University, Hiroshima, Japan. kubo-t@yasuda-u.ac.jp
authors.forename: Takanori
authors.initials: T
authors.lastname: Kubo
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Yanagihara
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Takei
authors.forename: Keichiro
authors.initials: K
authors.lastname: Mihara
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Sato
authors.forename: Toshio
authors.initials: T
authors.lastname: Seyama
mesh_terms: D045744:Cell Line, Tumor; D020868:Gene Silencing / Q000502:physiology*; D006367:HeLa Cells; D006801:Humans; D008055:Lipids / Q000737:chemistry*; D019308:Palmitic Acid / Q000737:chemistry; D034622:RNA Interference / Q000502:physiology; D012330:RNA, Double-Stranded / Q000737:chemistry* / Q000235:genetics*; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics*
chemical_list: D008055:Lipids; C086724:Lipofectamine; D012330:RNA, Double-Stranded; D042461:Vascular Endothelial Growth Factor A; D019308:Palmitic Acid