title: Effect of the guide strand 3'-end structure on the gene-silencing potency of asymmetric siRNA.
abstract: siRNAs are short dsRNAs that mediate efficient target gene silencing in a sequence-specific manner. We previously developed a novel siRNA structure, called asiRNA (asymmetric siRNA), which alleviates the off-target effects associated with conventional siRNA structures without decreasing target gene silencing potency. In the present study, we explored the effect of the guide strand 3'-end structure on the gene silencing potency of asiRNA. Interestingly, asiRNAs with a 21 nt guide strand solely composed of RNA resulted in gene silencing that was more than 6-fold more efficient compared with the corresponding asiRNA guide strand harbouring a dTdT (deoxythymidine dinucleotide) at its 3'-end. We demonstrated that the molecular basis of potency of the asiRNA with a 21 nt guide strand composed solely of RNA was due to the enhanced formation of the RISC (RNA-induced silencing complex) and increased affinity towards hAgo2 (human Argonaute2). Our observations may assist researchers in designing new asiRNAs with high on-target silencing efficiency with low off-target effects, which is critical for applications in both basic research and therapeutic development.
authors.affiliation: *Global Research Laboratory for RNAi Medicine, Department of Chemistry, Sungkyunkwan University, Suwon 440-746, Republic of Korea.
authors.forename: Sun Woo
authors.initials: SW
authors.lastname: Hong
authors.affiliation: †Department of Agricultural Biotechnology, Seoul National University, Seoul 151-921, Republic of Korea.
authors.forename: June Hyun
authors.initials: JH
authors.lastname: Park
authors.affiliation: *Global Research Laboratory for RNAi Medicine, Department of Chemistry, Sungkyunkwan University, Suwon 440-746, Republic of Korea.
authors.forename: Soyeong
authors.initials: S
authors.lastname: Yun
authors.affiliation: *Global Research Laboratory for RNAi Medicine, Department of Chemistry, Sungkyunkwan University, Suwon 440-746, Republic of Korea.
authors.forename: Chang Han
authors.initials: CH
authors.lastname: Lee
authors.forename: Chanseok
authors.initials: C
authors.lastname: Shin
authors.affiliation: *Global Research Laboratory for RNAi Medicine, Department of Chemistry, Sungkyunkwan University, Suwon 440-746, Republic of Korea.
authors.forename: Dong-ki
authors.initials: DK
authors.lastname: Lee
mesh_terms: D020413:3' Untranslated Regions; D000818:Animals; D060565:Argonaute Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D002460:Cell Line; D002474:Cell-Free System / Q000378:metabolism; D019040:E-Selectin / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D020868:Gene Silencing; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D007700:Kinetics; D051379:Mice; D059372:Nucleotide Motifs; D019859:Proto-Oncogene Proteins c-met / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000737:chemistry / Q000378:metabolism*; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D020413:3' Untranslated Regions; C466422:AGO2 protein, human; D060565:Argonaute Proteins; D019040:E-Selectin; D034741:RNA, Small Interfering; D011994:Recombinant Proteins; C491743:MET protein, human; D019859:Proto-Oncogene Proteins c-met