State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering , Nanjing University , Nanjing 210023 , P. R. China.
Department of Pharmaceutical and Biological Chemistry, UCL School of Pharmacy , University College London , London WC1N 1AX , United Kingdom.
ACS Nano. 2018 Nov 27;12(11):10797-10806. doi: 10.1021/acsnano.8b02403. Epub 2018 Oct 24.
The in situ generation of siRNAs in living cells can greatly enhance the specificity and efficiency of gene therapy. Inspired by the natural molecular machines that organize different compartments sequentially in a limited space to facilitate cellular process, this work constructs a DNA nanomachine (DNM) by alternately hybridizing two pairs of DNA/RNA hybrids to a DNA scaffold generated by rolling circle amplification for highly efficient in situ siRNA assembly in living cells. After target cell-specific delivery of DNM, intracellular specific microRNA can work as a trigger to operate the DNM by initiating DNA cascade displacement reaction between DNA/RNA hybrids along the scaffold for continuous generation of siRNAs. Using miR-21 as a model, efficient siRNAs generation is achieved via DNA templated cascade reaction, which demonstrated impressive suppressions to VEGF mRNA and protein expressions in cells and in vivo tumor growth and indicated promising application of the designed strategy in gene therapy.
在活细胞中原位生成 siRNA 可以极大地提高基因治疗的特异性和效率。受自然界中分子机器在有限空间内按顺序组织不同隔室以促进细胞过程的启发，本工作通过交替杂交两对 DNA/RNA 杂合体到滚环扩增产生的 DNA 支架上来构建 DNA 纳米机器（DNM），以在活细胞中高效原位组装 siRNA。在将 DNM 递送至靶细胞后，细胞内特定的 microRNA 可以作为触发物，通过启动支架上 DNA/RNA 杂合体之间的 DNA 级联置换反应来操作 DNM，从而持续生成 siRNA。使用 miR-21 作为模型，通过 DNA 模板化级联反应实现了高效的 siRNA 生成，该反应对细胞中 VEGF mRNA 和蛋白质表达以及体内肿瘤生长具有显著的抑制作用，表明所设计策略在基因治疗中有很好的应用前景。
