Endogenous miRNA-Activated DNA Nanomachine for Intracellular miRNA Imaging and Gene Silencing
Endogenous miRNA-Activated DNA Nanomachine for Intracellular miRNA Imaging and Gene Silencing
复制标题
用于细胞内 miRNA 成像和基因沉默的内源 miRNA 激活 DNA 纳米机器
DOI：
10.1021/acs.analchem.1c02907
复制
发表时间：
2021-10-08
影响因子：
7.4
通讯作者：
Wang, Kemin
中科院分区：
文献类型：
--
作者：
Li, Lie;Ren, Yazhou;Wang, Kemin
开发集诊断和治疗功能于一体的多功能纳米平台在癌症防治中一直是非常理想和具有挑战性的。在这里，我们报告了一种活细胞中的内源性miRNA激活的DNA纳米机器（EMDN），用于同时进行敏感的miRNA成像和可激活的基因沉默。EMDN是由两个功能性DNA单体（R/HP和F）与杂交链反应产生的DNA纳米线间隔杂交而构建的。在EMDN的靶细胞特异性转运后，细胞内let-7a miRNA通过DNA链置换级联启动DNA纳米机器，导致荧光共振能量转移信号放大和许多游离HP序列的释放。HP发夹结构的恢复进一步激活分裂DNA酶，以识别和切割EGR-1 mRNA，从而实现基因沉默治疗。所提出的EMDN显示有效的细胞内化、良好的生物稳定性、快速的反应动力学和避免假阳性信号的能力，从而确保活细胞中可靠的miRNA成像。同时，由细胞内特异性miRNA调控的分裂DNA酶活性的受控激活可能在癌症的精确治疗中具有前景。总的来说，该策略为肿瘤的早期临床诊断和可激活基因治疗提供了一个有价值的纳米平台。
The development of multifunctional nanoplatforms that integrate both diagnostic and therapeutic functions has always been extremely desirable and challenging in the cancer combat. Here, we report an endogenous miRNA-activated DNA nanomachine (EMDN) in living cells for concurrent sensitive miRNA imaging and activatable gene silencing. EMDN is constructed by interval hybridization of two functional DNA monomers (R/HP and F) to a DNA nanowire generated by hybridization chain reaction. After the target cell-specific transportation of EMDN, intracellular let-7a miRNA initiates the DNA nanomachine by DNA strand displacement cascades, resulting in an amplified fluorescence resonance energy-transfer signal and the release of many free HP sequences. The restoration of HP hairpin structures further activates the split-DNAzyme to identify and cleave the EGR-1 mRNA to realize gene silencing therapy. The proposed EMDN shows efficient cell internalization, good biological stability, rapid reaction kinetics, and the ability to avoid false-positive signals, thus ensuring reliable miRNA imaging in living cells. Meanwhile, the controlled activation of the split-DNAzyme activity regulated by the intracellular specific miRNA may be promising in the precise treatment of cancer. Collectively, this strategy provides a valuable nanoplatform for early clinical diagnosis and activatable gene therapy of tumors.