Pharmacodynamic and Pharmacokinetic Properties of Full Phosphorothioate Small Interfering RNAs for Gene Silencing In Vivo


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Date

2021-06

Publication Type

Journal Article

ETH Bibliography

yes

Citations

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Data

Abstract

State-of-the-art small interfering RNA (siRNA) therapeutics such as givosiran and fitusiran are constructed from three variable components: a fully-modified RNA core that conveys metabolic stability, a targeting moiety that mediates target-cell uptake, and a linker. This structural complexity poses challenges for metabolite characterization and risk assessment after long-term patient exposure. In this study, we show that basic phosphorothioate modification of a siRNA targeting the oncoprotein Lin28B provides a useful increase in metabolic stability, without greatly compromising potency. We found that its stability in vitro matched that of nanoparticle-free patisiran in serum and surpassed it in liver tritosome extracts, although it did not reach the stability of the fitusiran siRNA core structure. Liver and kidney were the main sites of accumulation after its subcutaneous administration in mice. Despite the lack of a delivery agent-free antitumor effect, we anticipate our study to be a starting point to develop alternative siRNA scaffolds that can be degraded into naturally-occurring metabolites and help alleviate the aforementioned challenges. Furthermore, Lin28B is a promising target for cancers, and the development of such simplified siRNA analogs, possibly together with novel targeting units, holds potential.

Publication status

published

Editor

Book title

Volume

31 (3)

Pages / Article No.

237 - 244

Publisher

Mary Ann Liebert

Event

Edition / version

Methods

Software

Geographic location

Date collected

Date created

Subject

phosphorothioate; SiRNA; backbone; delivery; stability

Organisational unit

03760 - Hall, Jonathan / Hall, Jonathan check_circle

Notes

Funding

169612 - Chemical Approaches to Functionalize Human microRNAs (SNF)

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