The Study of EGFR Expression on Malignant Skin Tumor and Molecular Labelling Using Gold Nanoparticles

Background: The potential benefits of a molecular characterization of cancer are clear. Because of this, there is pressing need to perform in vivo imaging of the molecular features of cancer. However, before designing an appropriate molecular targeting technique utiilizing a cancer-related target molecule such as epidermal growth factor receptor (EGFR), it is necessary to characterize the exact expression of the target molecule. Objective: The objective of this study was twofold. Our first goal was to characterize the expression of EGFR in skin cancer, and second, to develop nanoparticles conjugated with antibodies, demonstrating their use as optical probes for detecting cancer cells in vitro. Methods: We performed immunhistochemical analysis of EGFR expression in skin cancer using monoclonal antibodies. Gold nanoparticles were synthesized and allowed to conjugate to anti-EGFR in epithelial cancer tissue. Following an incubabtion period, we recorded surface plasmon resonance images using gold nanoparticles conjugated to anti-EGFR antibodies. Results: Specific membranous binding of EGFR was detected in all of the 10 non-melanoma skin cancers. Surface plasmon resonance images using gold nanoparticles also showed light scattering around tumor cells. Conclusion: These ex vivo results demonstrate that optical imaging using gold nanoparticles can allow selective detection of human epithelial cancer cells. Our study demonstrates the potential of gold nanoparticles to target, probe, and illuminate cancer cells making them an effective biomolecular cancer detection tool.