Proteomics Approaches for the Discovery of Potential Enzymatic Biomarkers for Early Diagnosis of Breast Cancer

Abstract

Breast cancer (BC) is one of the leading causes of death in Canadian women, with an average survival rate of 5 years after diagnosis. Early detection of BC can greatly improve patient outcomes and survival. However, a non-invasive BC detection method is not currently available in clinics. Recent studies suggest that proteins from small extracellular vesicles (sEVs) could be promising biomarkers for non-invasive BC early-stage diagnosis. sEVs are membrane-enclosed vesicles secreted by cells that drive different stages of carcinogenesis in BC. The purpose of this work was to analyze different published proteomics datasets to identify enzymes that could be potentially used as diagnostic biomarkers. Three cell line studies were compared, and overlapping BC proteins were highlighted with proteins found in sEVs from blood and plasma. In total, 106 proteins were selected based on the cell line studies, of which 40 have been identified in blood/plasma sEVs. These 106 proteins were mostly enriched with cell–cell signaling and DNA repair terms based on GO analysis. Furthermore, these 40 proteins contained 11 enzymes that can be explored as potential BC biomarkers. Future validation of enzymes using cancer cell lines and blood from BC patients remains to be determined.