Abstract B177: Detection and quantification of ligand-receptor interactions in formalin-fixed paraffin embedded samples by a novel proximity-based assay

Abstract

Abstract Aberrant activation of membrane receptors frequently occurs in human carcinomas. Detection of phosphorylated receptors is commonly used as an indicator of receptor activation in formalin-fixed paraffin embedded (FFPE) sections, a format used to preserve human tissue samples. This is the only format for readily available tissues from clinical trials and patient disease management. However, phosphorylation is generally less stable and consequently, less reproducible which can, in a clinical setting lead to ambiguous data. Here, we describe an alternative, novel approach to detect and quantify activation of receptors in FFPE samples. We used the ligand/receptor, HGF/c-MET as our model system. HGF is the only known ligand of c-MET and ligand binding causes activation of the c-MET receptor. Using, the VeraTag technology, a proximity-based assay, validated antibodies were used to detect and quantify total c-MET and total HGF in FFPE samples as well as to detect and quantify ligand stimulated and endogenous HGF/c-MET interactions in FFPE cell line pellets. The detection was validated in human non-small cell lung and stomach carcinoma FFPE samples. Our data demonstrate a novel approach to detect and quantify ligand-receptor interactions by VeraTag proximity-based assays that can be widely applied to measure activation of receptors in archived FFPE human tissue samples. Citation Information: Mol Cancer Ther 2009;8(12 Suppl):B177.