An Integrated Microfluidic Chip and Its Clinical Application for Circulating Tumor Cell Isolation and Single‐Cell Analysis

Circulating tumor cells (CTCs) represent invasive tumor cell populations and provide a noninvasive solution to the clinical management and research of tumors. Characterization of CTCs at single-cell resolution enables the comprehensive understanding of tumor heterogeneity and may benefit the diagnosis and treatment of cancer patients. However, most efforts have been made on enumeration and detection of CTCs, while little focus has been directed to single-cell study. Herein, an integrated microfluidic platform for single-cell isolation and analysis was established. After validating this platform on lung cancer cell lines, we detected and isolated single CTCs from the peripheral blood samples of 20 cancer patients before and after one treatment cycle. Furthermore, we performed single-cell whole-exome DNA sequencing on a single CTC from the peripheral blood sample of a representative early stage lung cancer patient. Among the blood samples of 20 patients, 15 of them were positive for CTC detection (75.0% detectable rate). Single-cell analysis revealed detailed genetic variations of the CTC, while six new gene mutations were detected in both single CTC and surgical specimen. This study provides a useful tool for the isolation and analysis of single CTCs from peripheral blood samples, which not only facilitates the early diagnosis of cancers but also helps to unravel the genetic information of tumor at a single-cell level. © 2019 International Society for Advancement of Cytometry.