False Biomarker Discovery due to Reactivity of a Commercial ELISA for CUZD1 with Cancer Antigen CA125
Abstract
BACKGROUND: By using proteomics and bioinformatics, we have previously identified a group of highly pancreas-specific proteins as candidate pancreatic ductal adenocarcinoma (PDAC) biomarkers. With the use of commercially available ELISAs, the performance of some of these candidates was initially evaluated in a relatively small serum cohort (n = 100 samples). This phase revealed that CUB and zona pellucida-like domains protein 1 (CUZD1) may represent a new, promising PDAC biomarker. METHODS: We performed detailed experiments to investigate the specificity of the commercial CUZD1 ELISA assay. CUZD1 was expressed in house in both bacteria and yeast expression systems. Recombinant CUZD1 and biological samples containing CUZD1, as well as commercial CUZD1 ELISA standards, were analyzed by Western blot, size exclusion HPLC, and mass spectrometry (LC-MS Orbitrap). RESULTS: We confirmed that instead of CUZD1, the commercial assay is recognizing a nonhomologous, known cancer antigen [cancer antigen 125 (CA125)]. CONCLUSIONS: We conclude that poor characterization of commercial ELISA assays is a factor that could lead to false biomarker discovery. To our knowledge, this is the first report documenting that a commercial ELISA marketed for one analyte (CUZD1) may, in fact, recognize a different, nonhomologous antigen (CA125).
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- Authors
- Prassas, I., Brinc, D., Farkona, S., Leung, F., Dimitromanolakis, A., Chrystoja, C. C., Brand, R., Kulasingam, V., Blasutig, I. M., & Diamandis, E. P.
- Affiliations
- Mount Sinai Hospital (CA)
- University of Toronto (CA)
- University of Pittsburgh (US)
- University Health Network (CA)
- Corresponding author
- Diamandis, Eleftherios P
- ORCID
- Venue
- Clinical Chemistry
- Publisher
- Oxford University Press (OUP)
- Published
- 2014-02-01
- Volume
- 60
- Issue
- 2
- Pages
- 381-388
- ISSN
- 0009-9147 (ISSN-L)
- 1530-8561
- OpenAlex
- W2100823111
- Cited by
- 52
- References
- 20
- Citations by year
- 2026: 2 · 2025: 6 · 2024: 5 · 2023: 1 · 2022: 4 · 2021: 3 · 2020: 1 · 2019: 1 · 2018: 7 · 2017: 5 · 2016: 5 · 2015: 6 · 2014: 5 · 2013: 1
- FWCI
- 3.03
- Type
- journal article
- Language
- en
- Open access
- closed
- Licence
- academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model (vor)
- Locations
- Clinical Chemistry (publishedVersion)
- PubMed (publishedVersion)
- Topics
- Health Sciences › Medicine › Oncology › Pancreatic and Hepatic Oncology Research
- Health Sciences › Medicine › Physiology › Clinical Laboratory Practices and Quality Control
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Advanced Biosensing Techniques and Applications
- Keywords
- CA125, assay cross-reactivity, recombinant protein characterization
- MeSH terms
- Calibration, Chromatography, Gel, Chromatography, High Pressure Liquid, Enzyme-Linked Immunosorbent Assay, False Negative Reactions, Humans, Membrane Proteins, Pancreatic Neoplasms, Sensitivity and Specificity, Reproducibility of Results, CA-125 Antigen, Carcinoma, Pancreatic Ductal, Cell Line, Tumor, Tandem Mass Spectrometry, Early Detection of Cancer
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