Theranostics 2020; 10(7):3022-3034. doi:10.7150/thno.42507 This issue
1. Departamento de Bioquímica y Biología Molecular, Facultad de Óptica y Optometría, Universidad Complutense de Madrid, 28037 Madrid, Spain.
2. UFIEC, Chronic Disease Programme, Instituto de Salud Carlos III, Majadahonda 28220, Madrid, Spain.
3. Departamento de Química Analítica, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain
4. Gastroenterology Unit, Hospital Universitario Clínico San Carlos, E-28040, Madrid, Spain
5. Pathology Department, University Hospital Gregorio Marañon, E-28007 Madrid, Spain
6. Unitat de Recerca Biomèdica, Hospital Universitari Sant Joan, Institut d´Investigació Sanitària Pere Virgili, Universitat Rovira i Virgili, Reus (Spain).
7. Department of Radiation Oncology, Hospital Universitari Sant Joan, Institut d´Investigació Sanitària Pere Virgili, Universitat Rovira i Virgili, Reus (Spain).
8. Medical Oncology Department, Hospital Universitario La Paz, E-28046, Madrid, Spain.
9. Departamento de Medicina, Facultad de Medicina, Instituto de Investigaciones Biomédicas "Alberto Sols", CSIC-UAM, E-28029, Madrid, Spain.
* Co-senior authors
Background and Purpose: The humoral immune response in cancer patients can be used for early detection of the disease. Autoantibodies raised against tumor-associated antigens (TAAs) are promising clinical biomarkers for reliable cancer diagnosis, prognosis, and therapy monitoring. In this study, an electrochemical disposable multiplexed immunosensing platform able to integrate difficult- and easy-to-express colorectal cancer (CRC) TAAs is reported for the sensitive determination of eight CRC-specific autoantibodies.
Methods: The electrochemical immunosensing approach involves the use of magnetic microcarriers (MBs) as solid supports modified with covalently immobilized HaloTag fusion proteins for the selective capture of specific autoantibodies. After magnetic capture of the modified MBs onto screen-printed carbon working electrodes, the amperometric responses measured using the hydroquinone (HQ)/H2O2 system were related to the levels of autoantibodies in plasma.
Results: The biosensing platform was applied to the analysis of autoantibodies against 8 TAAs described for the first time in this work in plasma samples from healthy asymptomatic individuals (n=3), and patients with high-risk of developing CRC (n=3), and from patients already diagnosed with colorectal (n=3), lung (n=2) or breast (n=2) cancer. The developed bioplatform demonstrated an improved discrimination between CRC patients and controls (asymptomatic healthy individuals and breast and lung cancer patients) compared to an ELISA-like luminescence test.
Conclusions: The proposed methodology uses a just-in-time produced protein in a simpler protocol, with low sample volume, and involves cost-effective instrumentation, which could be used in a high-throughput manner for reliable population screening to facilitate the detection of early CRC patients at affordable cost.
Keywords: colorectal cancer, biosensor, early cancer detection, electrochemical bioplatforms, halotag fusion proteins, liquid biopsy