Functional profiling of circulating tumor cells with an integrated vortex capture and single-cell protease activity assay
Functional profiling of circulating tumor cells with an integrated vortex capture and single-cell protease activity assay
复制标题
DOI：
10.1073/pnas.1803884115
复制
发表时间：
2018-10-02
影响因子：
11.1
通讯作者：
Di Carlo, Dino
中科院分区：
文献类型：
--
作者：
Dhar, Manjima;Lam, Jeffrey Nam;Di Carlo, Dino
假设肿瘤细胞使用蛋白水解酶来促进侵袭。循环肿瘤细胞（CTC）是否分泌这些酶来帮助转移尚不清楚。需要一种定量和高通量的方法来测定CTC分泌来解决这个问题。我们开发了一种集成的微流控系统，该系统在15分钟内将1 mL全血中> 100，000倍的罕见癌细胞浓缩到由检测试剂组成的50，000个2 nL液滴中。该系统按大小分离CTC，交换CTC周围的液体以去除污染物，引入基质金属蛋白酶（MMP）底物，并将CTC封装到微滴中。我们发现前列腺癌患者的CTC具有高于基线水平的MMP活性（1.7至200倍）。CTC的活性通常高于来自同一患者的白细胞（平均CTC/白细胞MMP活性比，2.6 +/-1.5）。CTC的更高MMP活性表明活性蛋白水解过程，其可以促进侵袭或免疫逃避，并且是相关的表型生物标志物，使得能够进行抗MMP疗法的伴随诊断。
Tumor cells are hypothesized to use proteolytic enzymes to facilitate invasion. Whether circulating tumor cells (CTCs) secrete these enzymes to aid metastasis is unknown. A quantitative and high-throughput approach to assay CTC secretion is needed to address this question. We developed an integrated microfluidic system that concentrates rare cancer cells >100,000-fold from 1 mL of whole blood into similar to 50,000 2-nL drops composed of assay reagents within 15 min. The system isolates CTCs by size, exchanges fluid around CTCs to remove contaminants, introduces a matrix metalloprotease (MMP) substrate, and encapsulates CTCs into microdroplets. We found CTCs from prostate cancer patients possessed above baseline levels of MMP activity (1.7- to 200-fold). Activity of CTCs was generally higher than leukocytes from the same patient (average CTC/leukocyte MMP activity ratio, 2.6 +/- 1.5). Higher MMP activity of CTCs suggests active proteolytic processes that may facilitate invasion or immune evasion and be relevant phenotypic biomarkers enabling companion diagnostics for anti-MMP therapies.