Precision N‐glycoproteomics reveals elevated LacdiNAc as a novel signature of intrahepatic cholangiocarcinoma

Abstract

Primary liver cancer, mainly comprising hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC), remains a major global health problem. Although ICC is clinically different from HCC, their molecular differences are still largely unclear. In this study, precision N‐glycoproteomic analysis was performed on both ICC and HCC tumors as well as paracancer tissues to investigate their aberrant site‐specific N‐glycosylation. By using our newly developed glycoproteomic methods and novel algorithm, termed ‘StrucGP’, a total of 486 N‐glycan structures attached on 1235 glycosites were identified from 894 glycoproteins in ICC and HCC tumors. Notably, glycans with uncommon LacdiNAc (GalNAcβ1‐4GlcNAc) structures were distinguished from their isomeric glycans. In addition to several bi‐antennary and/or bisecting glycans that were commonly elevated in ICC and HCC, a number of LacdiNAc‐containing, tri‐antennary, and core‐fucosylated glycans were uniquely increased in ICC. More interestingly, almost all LacdiNAc‐containing N‐glycopeptides were enhanced in ICC tumor but not in HCC tumor, and this phenomenon was further confirmed by lectin histochemistry and the high expression of β1‐4 GalNAc transferases in ICC at both mRNA and protein expression levels. The novel N‐glycan alterations uniquely detected in ICC provide a valuable resource for future studies regarding to the discovery of ICC diagnostic biomarkers, therapeutic targets, and mechanism investigations.

O-GlcNAcylation of Keratin 18 coordinates TCA cycle to promote cholangiocarcinoma progression

“…53,54 Glyco-biomarkers such as CA19-9 and CEA are up-regulated in CCA and exhibit diagnostic value. 55,56 Glyco-analytical methodologies including lectin blot, [57][58][59] glycan microarray 60 and glycoproteomic analysis [61][62][63][64] have been utilized to probe the glycobiology in CCA. In addition, abnormal sialylation, [65][66][67][68] fucosylation 69,70 and O-linked Nacetylgalactosamine (GalNAc) modification (O-GalNAcylation) 60,[71][72][73] have also been implicated in prognostic outcome in human cholangiocarcinoma.…”

Robust Glycoproteomics Platform Reveals a Tetra‐Antennary Site‐Specific Glycan Capping with Sialyl‐Lewis Antigen for Early Detection of Gastric Cancer

“…[12] Li et al detected the increase of LacdiNAc-containing N-glycans on 10 glycosites of 8 glycoproteins as a feature of intrahepatic cholangiocarcinoma using isotopic labeling-based quantitative N-glycoproteomic analysis. [13] These studies highlighted the potential of sitespecific glycans in tumor diagnosis using novel glycoproteomics approaches.…”

“…Recent advances in sample preparations, data acquisition methods, and spectra deciphering software have greatly facilitated highly sensitive profiling of site-specific glycosylation in cancer research. [12][13][14][15][16][17] For instance, Cao et al detected upregulated core-fucosylation at the N-glycosite 603 of EGFR in HCC via a sequential treatment of intact glycopeptides with enzymes (STAGE) strategy. [12] Li et al detected the increase of LacdiNAc-containing N-glycans on 10 glycosites of 8 glycoproteins as a feature of intrahepatic cholangiocarcinoma using isotopic labeling-based quantitative N-glycoproteomic analysis.…”

“…Recent advances in sample preparations, data acquisition methods, and spectra deciphering software have greatly facilitated highly sensitive profiling of site‐specific glycosylation in cancer research. [ 12 , 13 , 14 , 15 , 16 , 17 ] For instance, Cao et al detected upregulated core‐fucosylation at the N‐glycosite 603 of EGFR in HCC via a sequential treatment of intact glycopeptides with enzymes (STAGE) strategy. [ 12 ] Li et al.…”