Quantitation of putative colorectal cancer biomarker candidates in serum extracellular vesicles by targeted proteomics

Abstract

At the moment, there is no sensitive clinical test for detecting early-stage colorectal cancer (CRC). Target proteomics has enabled high-throughput verification of hundreds of biomarker candidate proteins. Using this technology, we verified 725 previously reported CRC biomarker candidate proteins that are functionally correlated with CRC in extracellular vesicles (EVs) from patients. Of these, 356 proteins were quantified, and 34 peptides (22 proteins) showed significant differences in the serum EVs between healthy controls and CRC patients of two independent cohorts (n = 77 and 84). These peptides were evaluated as single or multiple markers, and four single peptides in annexin family proteins and eight combinations of peptides showed area under the curve > 0.9 for discriminating between healthy controls and CRC patients. The sensitivities of annexins A3, A4, and A11 peptides for detecting early-stage CRC greatly exceed those of carcinoembryonic antigen. These peptides are promising biomarkers for early detection of CRC.

Proteomics of Extracellular Vesicles: Update on Their Composition, Biological Roles and Potential Use as Diagnostic Tools in Atherosclerotic Cardiovascular Diseases

“…An additional separation step of the extracted EV proteins is usually performed before MS analysis using either gel electrophoresis [ 125 ] or LC [ 126 , 127 ] to facilitate proteomic analysis removing the contaminants in the sample. Moreover, specific separation methods for the study of post-translational modifications of EV proteins have also been applied in many proteomic studies.…”

Proteomic Analysis of Extracellular Vesicles for Cancer Diagnostics

“…In cancer EV studies, SRM/MRM is one of the promising strategies to evaluate potential biomarkers using large scale clinical samples. Shiromizu et al examined serum‐EVs from healthy donors and patients with colorectal cancer (CRC) using SRM/MRM analysis . Among the 356 quantified proteins (stable isotope‐peptide labeled), 34 peptides from 22 proteins showed a significant difference between healthy and CRC patients .…”

“…Shiromizu et al examined serum‐EVs from healthy donors and patients with colorectal cancer (CRC) using SRM/MRM analysis . Among the 356 quantified proteins (stable isotope‐peptide labeled), 34 peptides from 22 proteins showed a significant difference between healthy and CRC patients . Further data analysis identified that annexins A3, A4, and A11 peptides may serve as promising biomarkers for early CRC detection …”

Exploring the key communicator role of exosomes in cancer microenvironment through proteomics

“…Not only ascites, but also serum exosome can be a good diagnostic marker. Annexin proteins, and tspan 1 from the serum exosome are suggested colon cancer diagnostic markers [35,117]. However, most cancer derived exosomes, as mentioned in breast and lung cancer derived exosomes as above, contain a lot more annexin and tetraspanin proteins than normal control derived exosome.…”