Microregional HER2/HER3 density on cancer cells based on multi-point binding detection using nanoparticle-modified...

Area of Science:

• Biotechnology
• Nanotechnology
• Biophysics

Background:

• Accurate quantification of protein expression and microregional density is crucial for precision medicine, cancer diagnostics, and predicting drug efficacy.
• Current techniques for evaluating protein expression on tissue sections lack sufficient accuracy for clinical outcome predictions.
• There is a need for advanced methods to precisely measure antigen densities at the microregional level.

Purpose of the Study:

• To develop and validate a novel atomic force microscopy (AFM)-based method for quantifying microregional antigen density.
• To assess the potential of this new method for improving cancer diagnostics and precision medicine applications.
• To demonstrate the method's ability to detect subtle differences in antigen distribution.

Main Methods:

• Modification of an AFM cantilever with nanoparticles coated with streptavidin (SA).
• Measurement of adhesion forces between SA-coated nanoparticles and biotinylated antibodies targeting specific antigens (HER2, HER3) on cancer cell lines (SKOV3, AU565, MCF7).
• Analysis of adhesion force histograms to determine microregional antigen densities at sub-30 nm resolution.

Main Results:

• The developed AFM method successfully generated unique adhesion force histograms for different cancer cell lines.
• These histograms reflected distinct microregional densities of human epidermal growth factor receptor type 2 (HER2) and type 3 (HER3).
• Higher adhesion forces correlated with multi-point bindings, enabling detection of antigen density variations.

Conclusions:

• The novel AFM-based method provides a sensitive approach for evaluating microregional antigen densities.
• This technique holds promise for advancing precision medicine by enabling more accurate cancer diagnosis and treatment response prediction.
• The method's ability to resolve nanoscale antigen distribution offers new insights into cancer biology.