title: Chemically modified symmetric and asymmetric duplex RNAs: an enhanced stability to nuclease degradation and gene silencing effect.
abstract: The present study accents on the relationship between dicing, nuclease stability, and RNAi activity of various types of chemically modified symmetric and asymmetric dsRNAs, covalently bound with amino-groups or cholesterol at one or both terminals. All modified dsRNAs were subjected to cleavage by recombinant Dicer enzyme. They possessed a high resistance to nuclease degradation in cell cultured medium and an excellent RNAi activity in viable cells. The best stability and RNAi activity was detected for 5'-sense amino-modified RNAs. These modifications manifested also a high long-term gene silencing effect within seven days post-transfection, while the RNAi activity of the native 21nt siRNA expired within two days. The conjugation of dsRNA with cholesterol at 5'-sense end resulted in easy intracellular delivery without transfection reagents. After a direct transfection in cells, the cholesterol-conjugated 27nt dsRNA possessed a higher RNAi activity than cholesterol-conjugated 21nt siRNA.
authors.affiliation: On-site Sensing and Diagnosis Research Laboratory, National Institute of Advanced Industrial Science and Technology (AIST), 807-1 Shuku-machi, Tosu 841-0052, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Kubo
authors.forename: Zhivko
authors.initials: Z
authors.lastname: Zhelev
authors.forename: Hideki
authors.initials: H
authors.lastname: Ohba
authors.forename: Rumiana
authors.initials: R
authors.lastname: Bakalova
mesh_terms: D001483:Base Sequence; D002784:Cholesterol / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D008954:Models, Biological; D008969:Molecular Sequence Data; D034622:RNA Interference; D012323:RNA Processing, Post-Transcriptional; D012330:RNA, Double-Stranded / Q000737:chemistry* / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D043244:Ribonuclease III / Q000378:metabolism; D012260:Ribonucleases / Q000737:chemistry*; D014162:Transfection
chemical_list: D012330:RNA, Double-Stranded; D011994:Recombinant Proteins; D002784:Cholesterol; D012260:Ribonucleases; D043244:Ribonuclease III