MICROVESICLE SURFACE PROTEIN DETECTION AS A POTENTIAL BIOMARKER IN COLORECTAL CANCER

Abstract Introduction Colorectal cancer (CRC) is the third leading cause of death from cancer in the world; early detection is a key factor for patient´s prognosis. Microvesicles (MVs) are subcellular structures delimited by lipid bilayer intimately involved in physio-pathological processes such as cancer. Our objective is the characterization and detection of surface proteins in plasma derived MVs, as well as their usefulness as a tool in the detection of CRC. Methods Circulating MVs in peripheral blood of healthy individuals, with adenomas, high grade adenoma or carcinoma were isolated and characterized. MVs CD9, CD147 and EpCaM MVs surface proteins quantification was performed using an innovative lateral flow immunoassay (LFIA) developed in our laboratory. Results The characterization of the plasma MVs confirmed our previous observations, presenting a lower concentration of MVs in the groups of high-grade adenoma and mainly CRC. However, the carcinoma group presents a higher amount of protein per MV suggesting a greater MV´s complexity in this group. The analysis of surface antigens by LFIA show an unexpectedly significant reduction of these proteins in the carcinoma group. Conclusions The detection of antigens on the surface of MVs by LFIA may be able to discriminate patients with CRC and could emerge as an alternative test that complements CRC screening programs.