title: Insights into glycan biosynthesis in chemically-induced hepatocellular carcinoma in rats: A glycomic analysis.
abstract: OBJECTIVE
  To evaluate the qualitative and quantitative changes in N-linked glycosylation, which occurred in association with diethyl nitrosamine-induced hepatocellular carcinoma (HCC) in rodents.
  
  
  METHODS
  Liver tissues of (1) normal (non-tumor-bearing) rats; and (2) tumor-bearing rats; were collected and were used for histological and GlycanMap analyses. Briefly, GlycanMap analysis is a high-throughput assay that provides a structural and quantitative readout of protein-associated glycans using a unique, automated 96-well assay technology coupled to matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and custom bioinformatics. Histopathological studies were carried out to ensure the development of HCC in the tested animals.
  
  
  RESULTS
  The N-glycomic analysis revealed 5 glycans; Glc₁Man₉GlcNAc₂, Gal₂Man₃GlcNac₄Fuc₁Neu₁, Man₄GlcNac₂, Gal₂Man₃GlcNac₄Neu₃OAc₃, and Man₃GlcNac₅ Fuc₁, which showed significant changes in rat HCC tissues when compared with normal liver tissues. Four glycans were increased (P < 0.05) and Glc₁Man₉GlcNAc₂ was decreased (5.89 ± 0.45 vs 3.54 ± 0.21, P < 0.01) in HCC tissues compared to normal liver tissues. An increase (66.5 ± 1.05 vs 62.7 ± 1.1, P < 0.05) in high-mannose structures in HCC rats was observed compared to normal rats. Importantly, HCC rats showed an increase (P < 0.05) in both tumor-associated carbohydrates and in branched glycans. The changes in glycans correlated well with glycan flow changes reported in the glycan biosynthetic pathway, which indicates the importance of enzyme activities involved in glycan synthesis at different subcellular localizations.
  
  
  CONCLUSIONS
  The reported HCC-associated changes in glycan flow and subcellular localization explain the increase in high mannose glycans and siayl Lewis glycans common in HCC liver tissues.
authors.affiliation: Amr Amin, Asma Bashir, Mohamed Lotfy, Department of Biology, College of Science, UAE University, Al-Ain 15551, United Arab Emirates.
authors.forename: Amr
authors.initials: A
authors.lastname: Amin
authors.affiliation: Amr Amin, Asma Bashir, Mohamed Lotfy, Department of Biology, College of Science, UAE University, Al-Ain 15551, United Arab Emirates.
authors.forename: Asma
authors.initials: A
authors.lastname: Bashir
authors.affiliation: Amr Amin, Asma Bashir, Mohamed Lotfy, Department of Biology, College of Science, UAE University, Al-Ain 15551, United Arab Emirates.
authors.forename: Nazar
authors.initials: N
authors.lastname: Zaki
authors.affiliation: Amr Amin, Asma Bashir, Mohamed Lotfy, Department of Biology, College of Science, UAE University, Al-Ain 15551, United Arab Emirates.
authors.forename: Diane
authors.initials: D
authors.lastname: McCarthy
authors.affiliation: Amr Amin, Asma Bashir, Mohamed Lotfy, Department of Biology, College of Science, UAE University, Al-Ain 15551, United Arab Emirates.
authors.forename: Sanjida
authors.initials: S
authors.lastname: Ahmed
authors.affiliation: Amr Amin, Asma Bashir, Mohamed Lotfy, Department of Biology, College of Science, UAE University, Al-Ain 15551, United Arab Emirates.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Lotfy
mesh_terms: D000818:Animals; D014408:Biomarkers, Tumor / Q000096:biosynthesis*; D006528:Carcinoma, Hepatocellular / Q000139:chemically induced / Q000378:metabolism*; D019295:Computational Biology; D004052:Diethylnitrosamine; D054794:Glycomics / Q000379:methods; D006031:Glycosylation; D057166:High-Throughput Screening Assays; D008114:Liver Neoplasms, Experimental / Q000139:chemically induced / Q000378:metabolism*; D008297:Male; D011134:Polysaccharides / Q000096:biosynthesis*; D017208:Rats, Wistar; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D014408:Biomarkers, Tumor; D011134:Polysaccharides; D004052:Diethylnitrosamine
keywords: Biosynthetic pathways; Glycomics; Hepatocellular carcinoma; Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry