ACS Nano. 2018 Apr 24;12(4):3311-3320. doi: 10.1021/acsnano.7b08199. Epub 2018 Mar 28.
Pancreatic ductal adenocarcinoma (PDAC) typically has nonspecific symptoms and is often found too late to treat. Because diagnosis of PDAC involves complex, invasive, and expensive procedures, screening populations at increased risk will depend on developing rapid, sensitive, specific, and cost-effective tests. Exosomes, which are nanoscale vesicles shed into blood from tumors, have come into focus as valuable entities for noninvasive liquid biopsy diagnostics. However, rapid capture and analysis of exosomes with their protein and other biomarkers have proven difficult. Here, we present a simple method integrating capture and analysis of exosomes and other extracellular vesicles directly from whole blood, plasma, or serum onto an AC electrokinetic microarray chip. In this process, no pretreatment or dilution of sample is required, nor is it necessary to use capture antibodies or other affinity techniques. Subsequent on-chip immunofluorescence analysis permits specific identification and quantification of target biomarkers within as little as 30 min total time. In this initial validation study, the biomarkers glypican-1 and CD63 were found to reflect the presence of PDAC and thus were used to develop a bivariate model for detecting PDAC. Twenty PDAC patient samples could be distinguished from 11 healthy subjects with 99% sensitivity and 82% specificity. In a smaller group of colon cancer patient samples, elevated glypican-1 was observed for metastatic but not for nonmetastatic disease. The speed and simplicity of ACE exosome capture and on-chip biomarker detection, combined with the ability to use whole blood, will enable seamless "sample-to-answer" liquid biopsy screening and improve early stage cancer diagnostics.
胰腺导管腺癌 (PDAC) 通常具有非特异性症状,并且通常发现得太晚而无法治疗。由于 PDAC 的诊断涉及复杂、侵入性和昂贵的程序,因此对高危人群进行筛查将取决于开发快速、敏感、特异性和具有成本效益的测试。外泌体是从肿瘤中释放到血液中的纳米级囊泡,已成为非侵入性液体活检诊断有价值的实体。然而,快速捕获和分析外泌体及其蛋白质和其他生物标志物一直很困难。在这里,我们提出了一种简单的方法,可将外泌体和其他细胞外囊泡的捕获和分析直接整合到 AC 电动微阵列芯片上,从全血、血浆或血清中进行。在这个过程中,不需要对样品进行预处理或稀释,也不需要使用捕获抗体或其他亲和技术。随后的芯片上免疫荧光分析允许在最短 30 分钟的总时间内对目标生物标志物进行特异性识别和定量。在这项初步验证研究中,发现聚糖蛋白 1 和 CD63 这两种生物标志物反映了 PDAC 的存在,因此用于开发用于检测 PDAC 的双变量模型。20 个 PDAC 患者样本可以与 11 个健康受试者区分开来,敏感性为 99%,特异性为 82%。在一个较小的结肠癌患者样本组中,观察到转移性疾病的聚糖蛋白 1 升高,但非转移性疾病则没有。ACE 外泌体捕获和芯片上生物标志物检测的速度和简单性,结合使用全血的能力,将实现无缝的“样本到答案”液体活检筛查,并改善早期癌症诊断。