Multiplexed single cell protein expression analysis in solid tumours using a miniaturised microfluidic assay

Area of Science:

• Proteomics
• Cancer Biology
• Translational Medicine

Background:

• Aberrant expression of tumor suppressor protein p53 and its phosphorylation are common in colorectal cancers.
• Investigating protein expression and modification at the single-cell level is crucial for understanding cancer heterogeneity and prognosis.

Purpose of the Study:

• To demonstrate a practical workflow for single cell proteomics in patient-derived colorectal cancer xenografts.
• To assess the viability of microfluidic antibody capture (MAC) technology for quantitative protein analysis at the single-cell level.

Main Methods:

• Utilized patient-derived colorectal cancer xenografts.
• Employed a microfluidic antibody capture (MAC) chip for protein analysis.
• Measured expression of p53 and phosphorylated p53 (at serine-15) in individual cancer cells.

Main Results:

• The MAC technology is effective for quantitative single cell protein expression and phosphorylation analysis.
• Demonstrated feasibility in microscopic amounts of clinically relevant tumor material.
• Revealed significant variability in p53 and phosphorylated p53 levels between individual cancer cells from the same tumor.

Conclusions:

• Single cell proteomics using MAC chips is a viable approach for clinical samples.
• This technology offers a potential translational route for medical diagnostics and therapeutic-associated single cell protein analysis.
• Highlights the power of single cell analysis in studying functional intratumour heterogeneity.