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

Area of Science:

• Oncology
• Biotechnology
• Genomics

Background:

• Epidermal Growth Factor Receptor (EGFR) mutations are key targets for tyrosine kinase inhibitor (TKI) cancer therapies.
• Detecting multiple EGFR mutations in rare cancer cell populations is clinically significant but challenging due to noise from wild-type cells.

Purpose of the Study:

• To validate a novel microfluidic chip-based method for single-cell level detection of EGFR multi-mutations.
• To enable cost-effective and precise identification of actionable mutations for targeted cancer therapy.

Main Methods:

• Single cells were trapped and immunofluorescently imaged on a microfluidic chip with silicon microwells to identify EGFR-expressing cells.
• EGFR-expressing cells were lysed in situ, and their lysates were retrieved without cross-contamination.
• Sanger sequencing was employed to detect EGFR multi-mutations, leveraging the exclusion of non-expressing cells to reduce noise.

Main Results:

• The microfluidic chip successfully identified EGFR-expressing cells and enabled precise detection of three key drug-related EGFR mutations.
• The method accurately identified mutations in samples with a low percentage of EGFR-mutated cells.
• The chip provided single-cell resolution, indicating which specific cells harbored mutations and if multiple mutations coexisted on the same cell.

Conclusions:

• The microfluidic chip-based method offers a sensitive and cost-effective approach for detecting EGFR multi-mutations at the single-cell level.
• This technology can enhance the utility of Sanger sequencing for routine clinical testing prior to EGFR-TKI targeted cancer therapy.
• The method facilitates personalized medicine by revealing mutation status at the individual cell level.