Basic Study
Copyright ©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Aug 7, 2022; 28(29): 3869-3885
Published online Aug 7, 2022. doi: 10.3748/wjg.v28.i29.3869
N-linked glycoproteomic profiling in esophageal squamous cell carcinoma
Qi-Wei Liu, Hao-Jie Ruan, Wei-Xia Chao, Meng-Xiang Li, Ye-Lin Jiao, Douglas G Ward, She-Gan Gao, Yi-Jun Qi
Qi-Wei Liu, Hao-Jie Ruan, Wei-Xia Chao, Meng-Xiang Li, She-Gan Gao, Yi-Jun Qi, Henan Key Laboratory of Microbiome and Esophageal Cancer Prevention and Treatment; Henan Key Laboratory of Cancer Epigenetics; Cancer Hospital, The First Affiliated Hospital, College of Clinical Medicine, Henan University of Science and Technology, Luoyang 471003, Henan Province, China
Ye-Lin Jiao, Department of Pathology, The First People’s Hospital of Luo Yang, Luoyang 471000, Henan Province, China
Douglas G Ward, Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, United Kingdom
Author contributions: Qi YJ and Gao SG designed and coordinated the study; Liu QW, Ruan HJ, Chao WX, Li MX, Jiao YL, and Ward DG performed the experiments, and acquired and analyzed the data; Qi YJ and Ward DG wrote the manuscript; and all authors approved the final version of the article.
Supported by National Natural Science Foundation of China, No. 81072039 and No. 81872037.
Institutional review board statement: The study was approved by the Ethics Committee of the Medical School, Henan University, China (ethics ref: 108) and conducted in accordance with the ethical guidelines of the 1975 Declaration of Helsinki.
Conflict-of-interest statement: All authors report no relevant conflicts of interest for this article.
Data sharing statement: No additional data are available.
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: Yi-Jun Qi, MD, PhD, Professor, Henan Key Laboratory of Microbiome and Esophageal Cancer Prevention and Treatment; Henan Key Laboratory of Cancer Epigenetics; Cancer Hospital, The First Affiliated Hospital, College of Clinical Medicine, Henan University of Science and Technology, No. 29 Jinghua Road, Luoyang 471003, Henan Province, China. qiyijun@haust.edu.cn
Received: January 14, 2022
Peer-review started: January 14, 2022
First decision: April 12, 2022
Revised: April 26, 2022
Accepted: July 6, 2022
Article in press: July 6, 2022
Published online: August 7, 2022
Processing time: 200 Days and 16.2 Hours
ARTICLE HIGHLIGHTS
Research background

Recent large-scale “omics” studies in esophageal squamous cell carcinoma (ESCC) have identified a myriad of aberrations at the levels of genome, epigenome, transcriptome, proteome, etc., revealing the high molecular heterogeneity of ESCC. However, protein post-translational modifications, such as glycosylation and phosphorylation, which provide additional significant biological insights, are missing.

Research motivation

The sugar chains of glycoproteins are involved in numerous physiological and pathological conditions. More than 50% of current cancer biomarkers are glycoproteins.

Research objectives

To identify N-linked glycoproteins associated with ESCC after isolation of N-linked glycoproteins using tandem multilectin affinity chromatography.

Research methods

N-linked glycoproteins were isolated from ESCC and adjacent non-tumor tissue samples using multilectin affinity chromatography. Two-dimensional gel electrophoresis (2-DE)-based and isobaric tags for relative and absolute quantification (iTRAQ) labeling-based mass spectrometry quantitation were performed in parallel to profile the N-linked glycoproteome in ESCC, followed by validation of candidate glycoprotein biomarkers using Western blot.

Research results

A total of 411 differentially expressed N-linked glycoproteins (DEGs) with potential glycosylation sites on proteins were identified by 2-DE-based and iTRAQ labeling-based quantitation, demonstrating the outperformance of iTRAQ labeling-based quantitation over 2-DE. These DEGs exhibited distinctive compositions in functional categories from differentially expressed proteins in ESCC. Western blot analysis validated the up-regulation of total procathepsin D and high-mannose procathepsin D, and the down-regulation of total haptoglobin, high-mannose clusterin, and GlcNAc/sialic acid-containing fraction of 14-3-3ζ in ESCC tissues. The serum levels of glycosylated fractions of clusterin, proline-arginine-rich end leucine-rich repeat protein, and haptoglobin in patients with ESCC were remarkably higher than those in healthy controls.

Research conclusions

This study identified the aberrant N-linked glycoproteome associated with ESCC, which will be a valuable resource for future investigations.

Research perspectives

In-depth characterization of the composition and structure of glycans associated with proteins can shed more lights on biological insights and clinical relevance of the identified DEGs in ESCC.