title: Synthesis of modified double stranded RNAs containing duplex regions between amide-linked RNA and RNA at both ends and enhanced nuclease resistance.
abstract: Synthetic short-interfering RNA (siRNA) has been a powerful tool to control gene expression. Chemical modification of the 3'-overhang regions of siRNA with amide-linked RNAs improved the exonuclease resistance and was compatible with RNAi function in cultured cells. To improve endonuclease resistance of the siRNA having amide-linked RNA modification at the 3'-terminal regions, we designed and synthesized new modified double stranded RNAs (dsRNAs) the 3'-terminal regions of which were modified with amide-linked RNA moieties and formed duplex structures with the complementary unmodified RNA moieties. The modified dsRNAs showed remarkable increase of stability in cell culture medium containing 10% serum in comparison with the modified siRNAs having 3'-overhang regions of amide-linked RNAs. The result suggests that the resistance of siRNA against endonuclease as well as 3'-exonuclease in serum can be enhanced by the introduction of the structures of amide-linked RNA:unmodified RNA duplexes at both ends of siRNA.
authors.affiliation: Department of Biosciences, Teikyo University of Science and Technology, Uenohara, Yamanashi 409-0193, Japan. iwase@ntu.ac.jp
authors.forename: Reiko
authors.initials: R
authors.lastname: Iwase
authors.forename: Rina
authors.initials: R
authors.lastname: Kurokawa
authors.forename: Junpei
authors.initials: J
authors.lastname: Ueno
mesh_terms: D000577:Amides / Q000737:chemistry; D004722:Endoribonucleases / Q000378:metabolism; D012330:RNA, Double-Stranded / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism; D034741:RNA, Small Interfering / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism; D013816:Thermodynamics
chemical_list: D000577:Amides; D012330:RNA, Double-Stranded; D034741:RNA, Small Interfering; D004722:Endoribonucleases