Oncology Department, Fujian Medical University Union Hospital, Fujian Provincial Key Laboratory of Translational Cancer Medicine, Fuzhou 350001, China.
Sinopharm Dongfeng General Hospital, Hubei University of Medicine, Shiyan 442008, China.
Molecules. 2022 Aug 22;27(16):5338. doi: 10.3390/molecules27165338.
Exosomal MicroRNA-21 (miRNA-21, miR-21) is significantly up-regulated in blood samples of patients with lung cancer. Exosomal-derived miR-21 can be used as a promising biomarker for the early diagnosis of lung cancer. This paper develops a fluorescent biosensor based on the combination of magnetic nanoparticles (MNPs), cascade strand displacement reaction (CSDR) and CRISPR/Cas12a to detect the exosomal miR-21 from lung cancer. The powerful separation performance of MNPs can eliminate the potential interference of matrix and reduce the background signal, which is very beneficial for the improvement of specificity and sensitivity. The CSDR can specifically transform one miR-21 into plenty of DNA which can specifically trigger the trans-cleavage nuclease activity of Cas12a, resulting in the cleavage of ssDNA bi-labeled with fluorescent and a quencher. Under the optimized experimental conditions, the developed fluorescence biosensor exhibited high sensitivity and specificity towards the determination of exosomal-derived miR-21 with a linear range from 10 to 1 × 10 fM and a low detection limit of about 0.89 fM. Most importantly, this method can be successfully applied to distinguish the exosomal miR-21 from the lung cancer patients and the healthy people.
外泌体 microRNA-21（miRNA-21，miR-21）在肺癌患者的血液样本中显著上调。外泌体衍生的 miR-21 可作为肺癌早期诊断的有前途的生物标志物。本文开发了一种基于磁性纳米粒子（MNPs）、级联链置换反应（CSDR）和 CRISPR/Cas12a 的组合的荧光生物传感器，用于检测来自肺癌的外泌体 miR-21。MNPs 的强大分离性能可以消除基质的潜在干扰并降低背景信号，这非常有利于提高特异性和灵敏度。CSDR 可以将一个 miR-21 特异性地转化为大量的 DNA，这些 DNA 可以特异性地触发 Cas12a 的转切割核酸酶活性，导致带有荧光和猝灭剂的 ssDNA 双标记的切割。在优化的实验条件下，所开发的荧光生物传感器对衍生自外泌体的 miR-21 的测定表现出高灵敏度和特异性，线性范围为 10 到 1×10 fM，检测限约为 0.89 fM。最重要的是，该方法可成功应用于区分肺癌患者和健康人的外泌体 miR-21。
