Anal Chem. 2020 Mar 17;92(6):4411-4418. doi: 10.1021/acs.analchem.9b05304. Epub 2020 Feb 26.
Quantifying intracellular microRNA (miRNA) is essential for diagnosis and prognosis of diseases because of its importance to the development and progression of complex diseases. The challenge is to develop methods that enable multiplex miRNAs detection in ultralow amounts and over broad concentration ranges. Inspired by the "tentacles" of an octopus, herein, we present a framework nucleic acid (FNA) capture for sensitive, rapid, and multiplexed imaging of miRNAs cancer biomarkers in living cells. The programmable FNA is designed using three DNA triangular prism (DTP) nanostructures carrying two pairs of metastable catalytic hairpin assembled (CHA) probes, AS1411 aptamer, and pendent biotinylated DNA strand in different vertexes and is further assembled via streptavidin to form the multivalent DTP (SA-DTP). The SA-DTP system acts as an octopus that captures the target cancer miRNAs quickly and delivers them preferentially among DTPs' "tentacles" in the SA-DTP system to produce strong, amplified fluorescence for detection. Precise multiplexed imaging of miRNA-155 and miRNA-21 cancer biomarkers' aberrant expression and dynamic change in different cells demonstrates the feasibility of both monitoring disease progression and evaluating therapeutic efficacy.
定量检测细胞内 microRNA（miRNA）对于疾病的诊断和预后至关重要，因为它对复杂疾病的发展和进展具有重要意义。挑战在于开发能够在超低量和广泛浓度范围内检测多重 miRNAs 的方法。受章鱼“触手”的启发，本文提出了一种用于在活细胞中灵敏、快速和多重成像 miRNA 癌症生物标志物的框架核酸（FNA）捕获方法。可编程 FNA 是使用三个携带两对亚稳态催化发夹组装（CHA）探针、AS1411 适体和末端生物素化 DNA 链的 DNA 三角棱柱（DTP）纳米结构设计的，在不同顶点进一步通过链霉亲和素组装形成多价 DTP（SA-DTP）。SA-DTP 系统充当章鱼，可快速捕获靶标癌症 miRNA，并在 SA-DTP 系统中“触手”之间优先传递它们，以产生用于检测的强、放大荧光。对 miRNA-155 和 miRNA-21 癌症生物标志物在不同细胞中的异常表达和动态变化的精确多重成像证明了监测疾病进展和评估治疗效果的可行性。
