title: Triazole- and Tetrazole-Bridged Nucleic Acids: Synthesis, Duplex Stability, Nuclease Resistance, and in Vitro and in Vivo Antisense Potency.
abstract: Antisense oligonucleotides are attractive therapeutic agents for several types of disease. One of the most promising modifications of antisense oligonucleotides is the introduction of bridged nucleic acids. As we report here, we designed novel bridged nucleic acids, triazole-bridged nucleic acid (TrNA), and tetrazole-bridged nucleic acid (TeNA), whose sugar conformations are restricted to N-type by heteroaromatic ring-bridged structures. We then successfully synthesized TrNA and TeNA and introduced these monomers into oligonucleotides. In UV-melting experiments, TrNA-modified oligonucleotides exhibited increased binding affinity toward complementary RNA and decreased binding affinity toward complementary DNA, although TeNA-modified oligonucleotides were decomposed under the annealing conditions. Enzymatic degradation experiments demonstrated that introduction of TrNA at the 3'-terminus rendered oligonucleotides resistant to nuclease digestion. Furthermore, we tested the silencing potencies of TrNA-modified antisense oligonucleotides using in vitro and in vivo assays. These experiments revealed that TrNA-modified antisense oligonucleotides induced potent downregulation of gene expression in liver. In addition, TrNA-modified antisense oligonucleotides showed a tendency for increased liver biodistribution. Taken together, our findings indicate that TrNA is a good candidate for practical application in antisense methodology.
authors.affiliation: Graduate School of Pharmaceutical Sciences, Osaka University , 1-6 Yamadaoka, Suita Osaka 565-0871, Japan.|Discovery Research Laboratory for Innovative Frontier Medicines, Shionogi & Co., Ltd. , 3-1-1 Futaba-cho, Toyonaka, Osaka 561-0825, Japan.
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Mitsuoka
authors.affiliation: Graduate School of Pharmaceutical Sciences, Osaka University , 1-6 Yamadaoka, Suita Osaka 565-0871, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Yamamoto
authors.affiliation: Discovery Research Laboratory for Innovative Frontier Medicines, Shionogi & Co., Ltd. , 3-1-1 Futaba-cho, Toyonaka, Osaka 561-0825, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Kugimiya
authors.affiliation: Graduate School of Pharmaceutical Sciences, Osaka University , 1-6 Yamadaoka, Suita Osaka 565-0871, Japan.
authors.forename: Reiko
authors.initials: R
authors.lastname: Waki
authors.affiliation: Graduate School of Pharmaceutical Sciences, Osaka University , 1-6 Yamadaoka, Suita Osaka 565-0871, Japan.
authors.forename: Fumito
authors.initials: F
authors.lastname: Wada
authors.affiliation: Graduate School of Pharmaceutical Sciences, Osaka University , 1-6 Yamadaoka, Suita Osaka 565-0871, Japan.
authors.forename: Saori
authors.initials: S
authors.lastname: Tahara
authors.affiliation: Graduate School of Pharmaceutical Sciences, Osaka University , 1-6 Yamadaoka, Suita Osaka 565-0871, Japan.
authors.forename: Motoki
authors.initials: M
authors.lastname: Sawamura
authors.affiliation: Graduate School of Pharmaceutical Sciences, Osaka University , 1-6 Yamadaoka, Suita Osaka 565-0871, Japan.
authors.forename: Mio
authors.initials: M
authors.lastname: Noda
authors.affiliation: Discovery Research Laboratory for Innovative Frontier Medicines, Shionogi & Co., Ltd. , 3-1-1 Futaba-cho, Toyonaka, Osaka 561-0825, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Fujimura
authors.affiliation: Research Laboratory for Development, Shionogi & Co., Ltd. , 3-1-1 Futaba-cho, Toyonaka, Osaka 561-0825, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Kato
authors.affiliation: Graduate School of Pharmaceutical Sciences, Osaka University , 1-6 Yamadaoka, Suita Osaka 565-0871, Japan.|Faculty of Pharmaceutical Sciences, Tokushima Bunri University , Nishihama, Yamashiro-cho, Tokushima 770-8514, Japan.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Hari
authors.affiliation: Graduate School of Pharmaceutical Sciences, Osaka University , 1-6 Yamadaoka, Suita Osaka 565-0871, Japan.
authors.forename: Satoshi
authors.identifier: 0000-0002-6842-6812
authors.initials: S
authors.lastname: Obika
mesh_terms: D018076:DNA, Complementary / Q000737:chemistry*; D003851:Deoxyribonucleases / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D009690:Nucleic Acid Conformation; D009696:Nucleic Acids / Q000138:chemical synthesis* / Q000737:chemistry; D016376:Oligonucleotides, Antisense / Q000737:chemistry*; D018075:RNA, Complementary / Q000737:chemistry*; D013777:Tetrazoles / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D018076:DNA, Complementary; D009696:Nucleic Acids; D016376:Oligonucleotides, Antisense; D018075:RNA, Complementary; D013777:Tetrazoles; C045574:1H-tetrazole; D003851:Deoxyribonucleases