Case Control Study
Copyright ©The Author(s) 2023. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Oncol. Jul 15, 2023; 15(7): 1227-1240
Published online Jul 15, 2023. doi: 10.4251/wjgo.v15.i7.1227
Proteomics-based identification of proteins in tumor-derived exosomes as candidate biomarkers for colorectal cancer
Ge-Yu-Jia Zhou, Dong-Yan Zhao, Teng-Fei Yin, Qian-Qian Wang, Yuan-Chen Zhou, Shu-Kun Yao
Ge-Yu-Jia Zhou, Department of Gastroenterology, China-Japan Friendship Hospital (Institute of Clinical Medical Sciences), Beijing 100029, China
Ge-Yu-Jia Zhou, Dong-Yan Zhao, Shu-Kun Yao, Graduate School, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, China
Teng-Fei Yin, Qian-Qian Wang, Yuan-Chen Zhou, Graduate School, Peking University China-Japan Friendship School of Clinical Medicine, Beijing 100029, China
Shu-Kun Yao, Department of Gastroenterology, China-Japan Friendship Hospital, Beijing 100029, China
Author contributions: Zhou GYJ designed the study, analyzed the data, and drafted the manuscript; Zhao DY and Yin TF provided guidance on experimental procedures; Wang Q and Zhou YC collected the samples and the clinical data; Yao SK supervised the study, revised the manuscript, and obtained the funding; all authors read and approved the final manuscript.
Supported by National Key Development Plan for Precision Medicine Research, No. 2017YFC0910002.
Institutional review board statement: This study was approved by the Ethics Committee of China-Japan Friendship Hospital (No. 2018-116-K85).
Informed consent statement: All study participants, or their legal guardian, provided informed written consent prior to study enrollment.
Conflict-of-interest statement: All authors declare no conflicts of interest for this article.
Data sharing statement: No additional data are available.
STROBE statement: The authors have read the STROBE Statement—checklist of items, and the manuscript was prepared and revised according to the STROBE Statement—checklist of items.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Shu-Kun Yao, Doctor, MD, PhD, Chief Physician, Professor, Department of Gastroenterology, China-Japan Friendship Hospital, No. 2 Yinghua East Road, Chaoyang District, Beijing 100029, China. shukunyao@126.com
Received: March 26, 2023
Peer-review started: March 26, 2023
First decision: April 18, 2023
Revised: April 28, 2023
Accepted: May 25, 2023
Article in press: May 25, 2023
Published online: July 15, 2023
Abstract
BACKGROUND

Colorectal cancer (CRC) is the second leading cause of cancer-related death, with high morbidity worldwide. There is an urgent need to find reliable diagnostic biomarkers of CRC and explore the underlying molecular mechanisms. Exosomes are involved in intercellular communication and participate in multiple pathological processes, serving as an important part of the tumor microenvironment.

AIM

To investigate the proteomic characteristics of CRC tumor-derived exosomes and to identify candidate exosomal protein markers for CRC.

METHODS

In this study, 10 patients over 50 years old who were diagnosed with moderately differentiated adenocarcinoma were recruited. We paired CRC tissues and adjacent normal intestinal tissues (> 5 cm) to form the experimental and control groups. Purified exosomes were extracted separately from each tissue sample. Data-independent acquisition mass spectrometry was implemented in 8 matched samples of exosomes to explore the proteomic expression profiles, and differentially expressed proteins (DEPs) were screened by bioinformatics analysis. Promising exosomal proteins were verified using parallel reaction monitoring (PRM) analysis in 10 matched exosome samples.

RESULTS

A total of 1393 proteins were identified in the CRC tissue group, 1304 proteins were identified in the adjacent tissue group, and 283 proteins were significantly differentially expressed between them. Enrichment analysis revealed that DEPs were involved in multiple biological processes related to cytoskeleton construction, cell movement and migration, immune response, tumor growth and telomere metabolism, as well as ECM-receptor interaction, focal adhesion and mTOR signaling pathways. Six differentially expressed exosomal proteins (NHP2, OLFM4, TOP1, SAMP, TAGL and TRIM28) were validated by PRM analysis and evaluated by receiver operating characteristic curve (ROC) analysis. The area under the ROC curve was 0.93, 0.96, 0.97, 0.78, 0.75, and 0.88 (P < 0.05) for NHP2, OLFM4, TOP1, SAMP, TAGL, and TRIM28, respectively, indicating their good ability to distinguish CRC tissues from adjacent intestinal tissues.

CONCLUSION

In our study, comprehensive proteomic profiles were obtained for CRC tissue exosomes. Six exosomal proteins, NHP2, OLFM4, TOP1, SAMP, TAGL and TRIM28, may be promising diagnostic markers and effective therapeutic targets for CRC, but further experimental investigation is needed.

Keywords: Exosomes, Colorectal cancer, Data-independent acquisition, Parallel reaction monitoring, Biomarker

Core Tip: We innovatively combined high-throughput quantitative proteomics analysis with colorectal cancer (CRC) tissue-originated exosomes. The comprehensive proteomic signature of CRC tissue exosomes was described using data-independent acquisition mass spectrometry, which revealed a mass of differentially expressed exosomal proteins. Six promising exosomal proteins, NHP2, OLFM4, TOP1, SAMP, TAGL and TRIM28, were verified by parallel reaction monitoring analysis and receiver operating characteristic curve analysis. The results indicated that these exosomal proteins could become potential diagnostic markers and effective therapeutic targets for CRC.