Integrated N-glycoproteomics Analysis of Human Saliva for Lung Cancer

J Proteome Res. 2022 Jul 1;21(7):1589-1602. doi: 10.1021/acs.jproteome.1c00701. Epub 2022 Jun 17.

Abstract

Aberrant protein N-glycosylation is a cancer hallmark, which has great potential for cancer detection. However, large-scale and in-depth analysis of N-glycosylation remains challenging because of its high heterogeneity, complexity, and low abundance. Human saliva is an attractive diagnostic body fluid, while few efforts explored its N-glycoproteome for lung cancer. Here, we utilized a zwitterionic-hydrophilic interaction chromatography-based strategy to specifically enrich salivary glycopeptides. Through quantitative proteomics analysis, 1492 and 1234 intact N-glycopeptides were confidently identified from pooled saliva samples of 10 subjects in the nonsmall-cell lung cancer group and 10 subjects in the normal control group. Accordingly, 575 and 404 N-glycosites were revealed for the lung cancer group and normal control group. In particular, 154 N-glycosites and 259 site-specific glycoforms were significantly dysregulated in the lung cancer group. Several N-glycosites located at the same glycoprotein and glycans attached to the same N-glycosites were observed with differential expressions, including haptoglobin, Mucin-5B, lactotransferrin, and α-1-acid glycoprotein 1. These N-glycoproteins were mainly related to inflammatory responses, infectious diseases, and cancers. Our study achieved comprehensive characterization of salivary N-glycoproteome, and dysregulated site-specific glycoforms hold promise for noninvasive detection of lung cancer.

Keywords: HILIC; N-glycosites; intact N-glycopeptides; lung cancer; saliva.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Glycopeptides / analysis
  • Glycoproteins / metabolism
  • Humans
  • Lung Neoplasms* / diagnosis
  • Proteome / metabolism
  • Proteomics
  • Saliva* / chemistry

Substances

  • Glycopeptides
  • Glycoproteins
  • Proteome