Li Lie, Jiang Huishan, Meng Xiangxian, Wen Xiaohong, Guo Qiuping, Li Zenghui, Wang Jie, Ren Yazhou, Wang Kemin
College of Biology, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Key Laboratory for Bio-Nanotechnology and Molecule Engineering of Hunan Province, Changsha, 410082, China.
College of Biology, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Key Laboratory for Bio-Nanotechnology and Molecule Engineering of Hunan Province, Changsha, 410082, China.
Talanta. 2021 Feb 1;223(Pt 1):121724. doi: 10.1016/j.talanta.2020.121724. Epub 2020 Oct 1.
Highly sensitive detection of cancer cells is of great importance for evaluating cancer development and improving survival rates. Here, we developed a split aptamer mediated proximity-induced hybridization chain reaction (HCR) strategy to meet this purpose. In this strategy, two split aptamer initiator probes, Sp-a and Sp-b, and two HCR hairpin probes, H1 and H2 were designed. The split aptamer initiator probes contained two components, split aptamer domains being responsible for target recognition, and the split initiator parts serving as the HCR promoter. In the presence of target cells, Sp-a and Sp-b would self-assemble on the cell surfaces, allowing the formation of an intact nicked initiator to activate the HCR reaction. Benefit from low background split aptamers and HCR amplification, this strategy presented high sensitivity in quantitative detection with a detection limit of 18 cells in 150 μL of binding buffer. Moreover, the approach exhibited excellent specificity to target cells in 10% fetal bovine serum and mixed cell samples, which was favorable for clinical diagnosis in complex biological environment. In addition, by changing the split aptamers attached to the split initiator, the proposed strategy can be expanded to detect various kinds of target cells. It may provide a novel and useful applicable platform for the sensitive detection of cancer cells in biomedicine and tumor-related studies.
癌细胞的高灵敏度检测对于评估癌症发展和提高生存率至关重要。在此，我们开发了一种分裂适体介导的邻近诱导杂交链式反应（HCR）策略来实现这一目的。在该策略中，设计了两种分裂适体引发探针Sp-a和Sp-b以及两种HCR发夹探针H1和H2。分裂适体引发探针包含两个组分，负责靶标识别的分裂适体结构域以及作为HCR启动子的分裂引发部分。在存在靶细胞的情况下，Sp-a和Sp-b会在细胞表面自组装，形成完整的带切口引发剂以激活HCR反应。受益于低背景的分裂适体和HCR扩增，该策略在定量检测中表现出高灵敏度，在150μL结合缓冲液中的检测限为18个细胞。此外，该方法在10%胎牛血清和混合细胞样本中对靶细胞表现出优异的特异性，这有利于在复杂生物环境中的临床诊断。此外，通过改变连接到分裂引发剂上的分裂适体，所提出的策略可以扩展到检测各种靶细胞。它可能为生物医学和肿瘤相关研究中癌细胞的灵敏检测提供一个新颖且有用的应用平台。
