RESUMO
We describe the synthesis and silencing activities of siRNA possessing N(1)-[3,5-bis(hydroxymethyl)phenyl]thymine (b(t)) in their 3'-overhang regions. We found that an siRNA possessing b(t) in the 3'-overhang region was more effective than an siRNA with natural nucleosides and the siRNA possessing 1,3-bis(hydroxymethyl)benzene (b) without a nucleobase at the 3'-overhang region in in vitro experiment using HeLa cells system. Furthermore, the RNA possessing b(t) at its 3'-end was more resistant to nucleolytic hydrolysis by snake venom phosphodiesterase (a 3'-exonuclease) than the RNA possessing the natural nucleoside 2'-deoxythymidine at the 3'-end. Thus, the compound b(t) will be a novel 3'-overhang moiety that can enhance the silencing activity and nuclease-resistant property of siRNAs.
Assuntos
Derivados de Benzeno/síntese química , Endorribonucleases/antagonistas & inibidores , Organofosfatos/síntese química , RNA Interferente Pequeno/síntese química , Timidina/química , Ureia/química , Sequência de Bases , Derivados de Benzeno/química , Endorribonucleases/biossíntese , Células HeLa , Humanos , Desnaturação de Ácido Nucleico , Organofosfatos/química , Diester Fosfórico Hidrolases/química , RNA Interferente Pequeno/química , RNA Interferente Pequeno/farmacologia , Venenos de Serpentes/enzimologia , Relação Estrutura-Atividade , Células Tumorais CultivadasRESUMO
[Chemical reaction: See text] The synthesis and properties of a nucleic acid analogue consisting of a benzene-phosphate backbone are described. The building blocks of the nucleic acid analogue are composed of bis(hydroxymethyl)benzene residues connected to nucleobases via the biaryl-like axis. Stabilities of the duplexes were studied by thermal denaturation. It was found that the thermal stabilities of the duplexes composed of the benzene-phosphate backbone are highly dependent on their sequences. The duplexes with the benzene-phosphate backbone comprised of the mixed sequences were thermally less stable than the natural DNA duplexes, whereas that composed of the homopyrimidine and homopurine sequences was thermally and thermodynamically more stable than the corresponding natural DNA duplex. It was suggested that the analogues more efficiently stabilize the duplexes in a B-form duplex rather than in an A-form duplex. Thus, the duplexes consisting of the benzene-phosphate backbone, especially composed of the homopyrimidine and homopurine sequences, may offer a novel structural motif useful for developing novel materials applicable in the fields of bio- and nanotechnologies.
