A simple G-quadruplex molecular beacon-based biosensor for highly selective detection of microRNA
A simple G-quadruplex molecular beacon-based biosensor for highly selective detection of microRNA
复制标题
一种简单的基于 G-四联体分子信标的生物传感器，用于高选择性检测 microRNA
DOI：
10.1016/j.bios.2016.07.060
复制
发表时间：
2017
影响因子：
12.6
通讯作者：
Fan Xiaolin
中科院分区：
文献类型：
--
作者：
Zhou Hui;Yang Chao;Chen Huifang;Li Xun;Li Yongdong;Fan Xiaolin
MicroRNAs(MiRNAs)家族成员在一碱基变异上通常是不同的。序列的高度同源性对单碱基选择性的miRNA分析提出了挑战。在G-四链分子信标(G4MB)和双链特异性核酸酶(DSN)的基础上，我们研制了一种简单、高选择性的miRNA扩增生物传感器。识别探针为带有G4基序茎的G4MB。在靶miRNAs存在的情况下，G4MB与靶miRNA完美杂交，形成G4MB-miRNA双链。然后，DSN随后切割G4MB-miRNA双链的G4MB，使目标miRNA循环，从而导致荧光信号放大。在没有靶miRNAs的情况下，由于G4基序的保护，DSN不能消化G4MB的茎，从而消除了假阳性信号，产生了低荧光背景。重要的是，G4MB和DSN的强大识别能力使该传感器适合于具有高单碱基选择性的miRNAs检测。与传统的基于线性单链DNA探针-DSN的方法相比，这种基于G4MB-DSN的方法将具有一碱基差异的相似miRNA序列的信号响应从24%降低到6%。此外，这种简单的传感器在癌细胞样本中也表现出很好的适用性，并且在一个样本中具有不同的miRNA靶标的多重能力，使其成为一种很有前途的临床诊断策略。
MicroRNAs (miRNAs) family members are usually different from each other in one-base variation. The high sequence homology poses a challenge for miRNA analysis with single-base selectivity. On the basis of G-quadruplex molecular beacons (G4MB) and duplex-specific nuclease (DSN), we developed a simple and highly selective amplification biosensor for miRNA detection. G4MB with a G4 motif stem is used as recognition probe. In the present of target miRNAs, G4MB hybridizes with target miRNA perfectly and forms a G4MB-miRNA duplex. Then, DSN subsequently cleaves the G4MB of the G4MB-miRNA duplex to recycle the target miRNA, which leads to fluorescence signal amplification. In the absence of target miRNAs, DSN can not digest the stem of G4MB because of the protection of G4 motif, which eliminates the false positive signal, and produces low fluorescence background. Importantly, the powerful discriminating abilities of both G4MB and DSN make the novel sensor suitable for miRNAs detection with high single-base selectivity. Comparing with traditional linear ssDNA probe-DSN-based method, the signal response of similar miRNA sequences with one-base difference has been reduced from 24% to 6% by using this G4MB-DSN-based method. Moreover, this simple sensor also exhibits a good applicability in cancer cell samples and a multiplex capability in one sample with different miRNA targets, making it a promising strategy for clinical diagnostics.