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β-1,3-Glucan/antisense oligonucleotide complex stabilized with phosphorothioation and its gene suppression
Shinichi Mochizuki1, Kazuo Sakurai, Kazuo Sakaurai
1Department of Chemistry and Biochemistry, The University of Kitakyushu, Wakamatsu-ku, Fukuoka, Japan.
Bioorganic Chemistry
|August 3, 2010
Summary
Antisense oligonucleotides (ASOs) with varying phosphorothioate (PS) content were complexed with schizophyllan (SPG). Increased PS content enhanced SPG complexation and thermal stability, with similar gene suppression efficacy.
Area of Science:
- Biochemistry
- Molecular Biology
- Drug Delivery
Background:
- Antisense oligonucleotides (ASOs) are crucial in gene therapy, with phosphorothioate (PS) analogues widely used for enhanced nuclease resistance.
- However, PS modifications can lead to non-specific side effects, necessitating investigation into optimal PS content.
- Schizophyllan (SPG), a β-1,3-glucan, shows potential for stabilizing oligonucleotide complexes.
Purpose of the Study:
- To investigate the impact of varying phosphorothioate (PS) content in antisense oligonucleotides (ASOs) on their complexation with schizophyllan (SPG).
- To evaluate the thermal stability and gene suppression efficacy of these SPG-ASO complexes.
- To explore the potential for reduced PS content in therapeutic oligonucleotides.
Main Methods:
- Preparation of complexes using schizophyllan (SPG) and ASOs with a dA₄₀ tail of varying PS content.
- Assessment of complexation ability and thermal stability through various biophysical techniques.
- Evaluation of gene suppression activity of the complexes in relevant biological systems.
Main Results:
- Increased PS content in the dA₄₀ tail of ASOs significantly improved complexation with SPG.
- The resulting SPG-ASO complexes exhibited enhanced thermal stability.
- Gene suppression efficacy of ASOs was comparable regardless of PS backbone modification, suggesting therapeutic sequences do not require full PS modification.
Conclusions:
- The study demonstrates that incorporating varying PS content in ASOs can optimize their complexation with SPG, leading to more stable therapeutic delivery systems.
- Reduced PS content in the antisense sequence backbone is feasible without compromising gene suppression ability, potentially mitigating PS-related side effects.
- These findings offer valuable insights into the interaction between β-1,3-glucan and DNA, aiding the development of improved therapeutic oligonucleotide delivery strategies.
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