Searching for new biomarkers for colorectal cancer: the value of proteins in extracellular vesicles

Abstract

[eng] Colorectal cancer (CRC) ranks as the fourth most common cancer globally, with a higher incidence in developed countries. Although early diagnosis by fecal occult blood test has decreased mortality rates, CRC remains a significant health concern. Since this diagnosis method gives false positives, the study aims to improve CRC detection by focusing on extracellular vesicles (EVs) as potential biomarkers. EVs, which contain various biomolecules including proteins and genetic material, are secreted by cells and play roles in tumor formation and progression. Their early release in CRC makes them promising for early detection. Samples were collected from 24 patients with positive fecal occult blood tests where EVs were isolated from stool samples using size-exclusion chromatography (SEC) with PURE-EV and IZON columns, remarking a better isolation by IZON. Proteomic analysis of isolated EVs from stool samples identified distinct protein expression patterns between healthy individuals and CRC patients. Key findings included upregulated and downregulated proteins in cancer patients which could be used as biomarkers The study highlights the feasibility of using EVs isolated from stool samples for early CRC detection, providing a non-invasive method to improve diagnostic accuracy and reduce unnecessary colonoscopies. Future research should focus on validating identified biomarkers in larger cohorts.