Dual immunoplatform to assess senescence biomarkers TIMP-1 and GDF-15: Advancing in the understanding of colorectal cancer

Abstract

In this work, we report the development of electrochemical bioplatforms for both the single determination of TIMP-1 and the simultaneous determination of TIMP-1 and GDF-15, two biomarkers of cellular senescence and prognosis in colorectal cancer (CRC). The designed immunoplatforms rely on a sandwich-type configuration labeled with horseradish peroxidase (HRP) built on magnetic microsupports and involve a pair of specific an tibodies to capture and detect each target protein. Amperometric readout was performed upon trapping the magnetic bioconjugates on the surface of either single or dual disposable carbon electrodes, using the hydro quinone/hydrogen peroxide (HQ/H2O2) system. The attractive analytical performance of the TIMP-1 bio platform, achieving a LOD of 13.0 pg mL‒1 and a dynamic range between 43.4 and 2500 pg mL‒1, led us to exploit it for TIMP-1 determination in cell extracts and tissues of CRC samples. The results showed the possibility of discriminating the metastatic capabilities of cells and detecting CRC patients, after just a simple dilution and in only 60 min. The multiplexing feasibility of the developed immunoplatform allowed the implementation of a dual assay for the simultaneous determination of TIMP-1 (LOD 19.2 pg mL‒1) and GDF-15 (LOD 16.6 pg mL‒1 ). The dual platform was used for the analysis of CRC samples (plasma and cell secretomes) in just 75 min and using a very simple protocol. These characteristics make the developed immunoplatform a very attractive tool to face particularly challenging samples, such as secretomes or plasma from CRC patients, due to the required sensi tivity, thus providing a better snapshot of CRC.