Protein chip based miniaturized assay for the simultaneous quantitative monitoring of cancer biomarkers in tissue extracts

Protein chip based miniaturized assay for the simultaneous quantitative monitoring of cancer biomarkers in tissue extracts
Weissenstein U, Schneider MJ, Pawlak M, Cicenas J, Eppenberger-Castori S, Oroszlan P, Ehret S, Geurts-Moespot A, Sweep FC, Eppenberger U
Proteomics. 2006; 6 (5): 1427-1436. DOI: 10.1002/pmic.200500078

A multiplexed fluorescence immunoassay using a novel planar waveguide technology-based microarray system, ZeptoMARK (Zeptosens), was developed to detect simultaneously urokinase-type plasminogen activator (uPA), plasminogen activator inhibitor-1 (PAI-1), and vascular endothelial growth factor (VEGF) in extracts of breast cancer tissues. The three analytes assay was cross-validated with single-analyte ELISA/chemiluminescence immunosorbent assay tests, revealing good correlations and enhanced assay sensitivities (LODs) of 1 pg/mL for uPA, 33 pg/mL for PAI-1, and 1 pg/mL for VEGF. Values were well within the 80-120% limits for assay recovery and within the +/-20% limits for assay precision. The uPA, PAI-1, and VEGF results obtained from 50 breast cancer cytosols using the protein array system demonstrated that the microarray-based multiplexed assay is a sensitive and robust tool to be used for the simultaneous quantification of cancer markers in small breast cancer tissue samples (core biopsies). The miniaturized, multiplexed assay format has a potential to be used for the quantitative analysis of a larger set of validated markers with significance in disease management. Pubmed