title: Protein chip based miniaturized assay for the simultaneous quantitative monitoring of cancer biomarkers in tissue extracts.
abstract: 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.
authors.affiliation: Oncoscore AG, Riehen, Switzerland.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Weissenstein
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Schneider
authors.forename: Michael
authors.initials: M
authors.lastname: Pawlak
authors.forename: Jonas
authors.initials: J
authors.lastname: Cicenas
authors.forename: Serenella
authors.initials: S
authors.lastname: Eppenberger-Castori
authors.forename: Peter
authors.initials: P
authors.lastname: Oroszlan
authors.forename: Sabine
authors.initials: S
authors.lastname: Ehret
authors.forename: Anneke
authors.initials: A
authors.lastname: Geurts-Moespot
authors.forename: Fred C G J
authors.initials: FC
authors.lastname: Sweep
authors.forename: Urs
authors.initials: U
authors.lastname: Eppenberger
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis*; D001943:Breast Neoplasms / Q000737:chemistry*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007118:Immunoassay / Q000379:methods*; D017395:Plasminogen Activator Inhibitor 1 / Q000032:analysis; D040081:Protein Array Analysis / Q000295:instrumentation / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013223:Statistics as Topic; D014020:Tissue Extracts / Q000737:chemistry*; D014568:Urokinase-Type Plasminogen Activator / Q000032:analysis; D042461:Vascular Endothelial Growth Factor A / Q000032:analysis
chemical_list: D014408:Biomarkers, Tumor; D017395:Plasminogen Activator Inhibitor 1; D014020:Tissue Extracts; D042461:Vascular Endothelial Growth Factor A; D014568:Urokinase-Type Plasminogen Activator