Personalized Diagnostics: Receptor Specific Gold Nanorods Used For Accurate Diagnosis Of Egfr Expression In Human Tumor Tissues

Proceedings: AACR Annual Meeting 2014; April 5-9, 2014; San Diego, CA Objective: The purpose of this study was to apply the enhanced surface chemistry and imaging properties of gold nanorods to the area of tumor protein diagnostics in order to give an accurate, quantifiable interpretation of a patient's biomarker status. The epidermal growth factor receptor (EGFR; HER1) is a cell surface receptor that regulates cell migration, adhesion, and proliferation. EGFR is commonly overexpressed in a variety of cancers. EGFR expression testing has been mandated by insurance companies in many areas before therapy can be given. Current methods of EGFR evaluation have been shown to be unreliable, thus EGFR was chosen as a target of interest for our studies. Methods: Gold nanorods (GNR) of aspect ratio 3:4 were prepared using an established seed-mediated growth method. The GNR were then PEGylated and conjugated with a unique modified peptide that has shown specific affinity for the EGF receptor. The product was characterized to show stability and presence of surface-bound peptide. The compound known as GNR-1070 was used to examine correlations between EGFR expression and gold present on the membranes of human cell lines and paraffin-embedded tissue samples. Results: In cell lines that are known to express EGFR, gold particles were identified bound to the membranes. The amount of bound gold correlated with the degree of EGFR expression of each cell line. Histochemical analysis of paraffin-embedded human tissue lines also correlated with the amount of gold bound to the membranes of the tissues. Conclusion: Gold nanorods conjugated with receptor-specific peptides can be used to give an accurate evaluation of protein expression in human cell lines and tissue samples. Citation Format: Chuck Caldwell, Ajit Zambre, Dhananjay Suresh, Gerald Arthur, Raghuraman Kannan. Personalized diagnostics: Receptor specific gold nanorods used for accurate diagnosis of EGFR expression in human tumor tissues. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1903. doi:10.1158/1538-7445.AM2014-1903