Poster abstracts
Poster number 44 submitted by Xijun Piao
The effect of chemical modifications on thermal and in vivo stability of phi29 bacteriophage RNA three-way junction
Xijun Piao (College of Pharmacy & Center for RNA Nanobiotechnology and Nanomedicine), Hongzhi Wang (College of Pharmacy & Center for RNA Nanobiotechnology and Nanomedicine), Daniel W. Binzel (College of Pharmacy & Center for RNA Nanobiotechnology and Nanomedicine), Peixuan Guo (College of Pharmacy; Center for RNA Nanobiotechnology and Nanomedicine; College of Medicine; Dorothy M. Davis Heart and Lung Research Institute; James Comprehensive Cancer Center)
Abstract:
The RNA three-way junction (3WJ) derived from phi29 bacteriophage DNA packaging motor has recently been used as a vehicle for targeted drug delivery. The high thermal stability and strong resistance to in vivo degradation of this nucleic acid-based platform are crucial to retain hybridized and intact 3WJ. Here we report the effects of different chemical modifications on the thermal and in vivo stability of this 3WJ. It was found that the thermal stability gradually increased by chemical modification in the order of phosphorothioate DNA < DNA < RNA < 2'-F < LNA. This is supported by the studies on strand displacement and the melting of homogeneous and heterogeneous 3WJs. By simply mixing different chemically-modified oligonucleotides, the thermal stability of this 3WJ can be tuned to cover a wide range of melting temperatures (Tm's) from 21.2 oC to over 95 oC. The LNA 3WJ was found resistant to boiling temperature denaturation, 8 M urea denaturation and 50% serum degradation. Interveinal injection of fluorescent LNA/2’-F hybrid 3WJs into mice and analysis of urine revealed its exceptional in vivo stability. It is thus concluded that incorporation of LNA into RNA nanoparticles derived from phi29 3WJ can extend the in vivo half-life of the RNA nanoparticles and it is thus expected to improve the pharmacokinetics profile of phi29 3WJ.
References:
Xijun Piao, Hongzhi Wang, Daniel W Binzel, and Peixuan Guo*, “Assessment and Comparison of Thermal Stability and In vivo stability of Phosphorothioate-DNA, DNA, RNA, 2’-F RNA and LNA in the Context of Phi29 pRNA 3WJ”, RNA, 2018, 24, 67-76.
Keywords: Three-way junction, thermal stability, in vivo stability