Imad Tarhoni1, Cristina L Fhied2, Mark Pool2, Michael J Liptay3, Philip Bonomi4, Christopher W Seder3, Jeffrey A Borgia1,2. 1. a Departments of Biochemistry , Rush University Medical Center , Chicago , IL, USA. 2. b Departments of Pathology , Rush University Medical Center , Chicago , IL, USA. 3. c Departments of Cardiovascular and Thoracic Surgery , Rush University Medical Center , Chicago , IL, USA. 4. d Departments of Medical Oncology , Rush University Medical Center , Chicago , IL, USA.
Abstract
BACKGROUND: Angiogenesis is associated with tumor progression in a range of malignancies. Herein, we develop custom immunobead assays for several mechanistically important targets and evaluated these against sera from cohorts of non-small cell lung cancer (NSCLC) patients. METHODS: Antigen "capture" antibodies for midkine, syndecan-1, and ANGPTL4 were independently conjugated to MagPlex® Microspheres using standard carbodiimide/NHS-based chemistry. These reagents served as the basis for quantitative sandwich assay assembly using biotinylated detection antibodies and R-phycoerythrin-conjugated streptavidin reporter system. Standard curves were created using dilution series of recombinant target proteins with assay performance characteristics calculated, accordingly. Finally, we evaluated a range of serum samples from NSCLC patients (n = 32) to verify assay performance. RESULTS: Multiplexed assays for midkine, syndecan-1, and ANGPTL4 were developed with three orders of magnitude in dynamic range, excellent intra- and inter-assay precision, and accuracy parameters (<10%, and <15% variability, respectively). Detection and quantifications limits were suitable for the three assays to efficiently evaluate sera across a range of disease stages with a four-fold dilution factor. CONCLUSION: We successfully developed and analytically validated a 3-plex immunobead assay for quantifying midkine, syndecan-1, and ANGPTL4 in patient sera. This multiplexed assay will provide an important tool for future studies delineating the role of angiogenesis in lung cancer progression.
BACKGROUND: Angiogenesis is associated with tumor progression in a range of malignancies. Herein, we develop custom immunobead assays for several mechanistically important targets and evaluated these against sera from cohorts of non-small cell lung cancer (NSCLC) patients. METHODS: Antigen "capture" antibodies for midkine, syndecan-1, and ANGPTL4 were independently conjugated to MagPlex® Microspheres using standard carbodiimide/NHS-based chemistry. These reagents served as the basis for quantitative sandwich assay assembly using biotinylated detection antibodies and R-phycoerythrin-conjugated streptavidin reporter system. Standard curves were created using dilution series of recombinant target proteins with assay performance characteristics calculated, accordingly. Finally, we evaluated a range of serum samples from NSCLCpatients (n = 32) to verify assay performance. RESULTS: Multiplexed assays for midkine, syndecan-1, and ANGPTL4 were developed with three orders of magnitude in dynamic range, excellent intra- and inter-assay precision, and accuracy parameters (<10%, and <15% variability, respectively). Detection and quantifications limits were suitable for the three assays to efficiently evaluate sera across a range of disease stages with a four-fold dilution factor. CONCLUSION: We successfully developed and analytically validated a 3-plex immunobead assay for quantifying midkine, syndecan-1, and ANGPTL4 in patient sera. This multiplexed assay will provide an important tool for future studies delineating the role of angiogenesis in lung cancer progression.