Identifying EGFR-Expressed Cells and Detecting EGFR Multi-Mutations at Single-Cell Level by Microfluidic Chip

• Main Authors: Ren Li, Mingxing Zhou, Jine Li, Zihua Wang, Weikai Zhang, Chunyan Yue, Yan Ma, Hailin Peng, Zewen Wei, Zhiyuan Hu
• Format: Article
• Language: English
• Published: SpringerOpen 2017-11-01
• Series: Nano-Micro Letters
• Subjects: EGFR mutation; Single-cell analysis; Microfluidic chip; Tyrosine kinase inhibitor
• Online Access: http://link.springer.com/article/10.1007/s40820-017-0168-y

Abstract EGFR mutations companion diagnostics have been proved to be crucial for the efficacy of tyrosine kinase inhibitor targeted cancer therapies. To uncover multiple mutations occurred in minority of EGFR-mutated cells, which may be covered by the noises from majority of un-mutated cells, is currently becoming an urgent clinical requirement. Here we present the validation of a microfluidic-chip-based method for detecting EGFR multi-mutations at single-cell level. By trapping and immunofluorescently imaging single cells in specifically designed silicon microwells, the EGFR-expressed cells were easily identified. By in situ lysing single cells, the cell lysates of EGFR-expressed cells were retrieved without cross-contamination. Benefited from excluding the noise from cells without EGFR expression, the simple and cost-effective Sanger’s sequencing, but not the expensive deep sequencing of the whole cell population, was used to discover multi-mutations. We verified the new method with precisely discovering three most important EGFR drug-related mutations from a sample in which EGFR-mutated cells only account for a small percentage of whole cell population. The microfluidic chip is capable of discovering not only the existence of specific EGFR multi-mutations, but also other valuable single-cell-level information: on which specific cells the mutations occurred, or whether different mutations coexist on the same cells. This microfluidic chip constitutes a promising method to promote simple and cost-effective Sanger’s sequencing to be a routine test before performing targeted cancer therapy.