Hunan Provincial Key Laboratory of Micro & Nano Materials Interface Science, College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083, Hunan, People's Republic of China.
Henan Province of Key Laboratory of New Optoelectronic Functional Materials, Anyang Normal University, Anyang, 455000, Henan, People's Republic of China.
Sci Rep. 2022 Sep 27;12(1):16093. doi: 10.1038/s41598-022-20453-8.
Abnormal expression levels of miRNA are associated with various tumor diseases, for example, glioma tumors are characterized by the up-regulation of miRNA-182. Surface plasmon resonance (SPR) assay for miRNA-182 from glioma patients was performed via DNA walking amplification strategy. The duplex between aminated swing arm DNA (swDNA) and block DNA (blDNA), and aminated track DNA (trDNA) with a biotin tag were tethered on the poly(ethylene glycol) (PEG)-modified chips. Upon formation of miRNA/blDNA duplex, the SPR signal decreased with the walking process of swDNA, as the biotinylated fragment of trDNA (biotin-TTGGAGT) was detached from the sensor surface caused by the nicking endonuclease Nb.BbvCI. Such a repeated hybridization and cleavage cycle occurred continuously and the detachment of more biotinylated fragments of trDNA from the chips led to the attachment of fewer streptavidin (SA) molecules and then smaller SPR signals. MiRNA-182 with concentrations ranging from 5.0 fM to 1.0 pM could be readily determined and a detection limit of 0.62 fM was achieved. The proposed method was highly selective and possessed remarkable capability for evaluating the expression levels of miRNA-182 in serum samples from healthy donors and glioma patients. The sensing protocol holds great promise for early diagnosis of cancer patients.
miRNA 的异常表达水平与各种肿瘤疾病有关，例如，神经胶质瘤肿瘤的特征是 miRNA-182 的上调。通过 DNA 行走扩增策略对神经胶质瘤患者的 miRNA-182 进行表面等离子体共振（SPR）分析。带氨基的摆动臂 DNA（swDNA）和带有生物素标记的阻断 DNA（blDNA）与氨基跟踪 DNA（trDNA）之间的双链体被连接到聚乙二醇（PEG）修饰的芯片上。形成 miRNA/blDNA 双链体后，随着 swDNA 的行走过程，SPR 信号降低，因为带生物素的 trDNA 片段（biotin-TTGGAGT）由于内切核酸酶 Nb.BbvCI 的切割而从传感器表面脱离。这种重复的杂交和切割循环不断发生，更多的生物素化 trDNA 片段从芯片上脱离导致更少的链霉亲和素（SA）分子附着，从而导致更小的 SPR 信号。可以轻松测定浓度范围为 5.0 fM 至 1.0 pM 的 miRNA-182，检测限达到 0.62 fM。该方法具有高度选择性，能够显著评估健康供体和神经胶质瘤患者血清样本中 miRNA-182 的表达水平。该传感方案有望用于癌症患者的早期诊断。
