Simple method for quantitative analysis of N-linked glycoproteins in hepatocellular carcinoma specimens.
Changes in N-linked glycan structures are related to the initiation and progression of hepatocellular carcinoma (HCC), one of the most common fatal cancers worldwide. In this study, we describe a simple and an efficient strategy for the selective identification and quantitation of N-linked glycoproteins that does not require extensive enrichment steps prior to MS/MS analysis. With this approach, N-linked glycoprotein differences between the plasma of healthy and HCC patients were selectively quantified after iTRAQ labeling. We identified a total of 14 N-linked glycopeptides with higher expression in HCC patient plasma than in healthy controls (>or=1.5 fold). Additionally, we characterized alterations in the glycan structures of vitronectin (Asn-169, 242) and antithrombin III (Asn-225) that were identified in HCC patient plasma. The intact glycopeptides with native glycan structures were also elevated in HCC tumor tissue. Taken together, these data support the utility of our approach for high throughput global profiling and quantification of the N-linked glycopeptides to identify disease biomarkers.
Lee
Hyoung-Joo
HJ
Department of Biochemistry and Biomedical Sciences, College of Life Sciences and Biotechnology, World Class University Program, Yonsei Proteome Research Center and Biomedical Proteome Research Center, Yonsei University, Seoul 120-749, Korea.
Na
Keun
K
Choi
Eun-Young
EY
Kim
Kyung Sik
KS
Kim
Hoguen
H
Paik
Young-Ki
YK
D000595:Amino Acid Sequence; D000990:Antithrombin III / Q000032:analysis; D014408:Biomarkers, Tumor / Q000097:blood*; D006528:Carcinoma, Hepatocellular / Q000097:blood*; D006023:Glycoproteins / Q000097:blood*; D006801:Humans; D007553:Isotope Labeling; D008113:Liver Neoplasms / Q000097:blood*; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000097:blood; D015203:Reproducibility of Results; D053719:Tandem Mass Spectrometry / Q000379:methods; D019096:Vitronectin / Q000097:blood
D014408:Biomarkers, Tumor; D006023:Glycoproteins; D010446:Peptide Fragments; D019096:Vitronectin; D000990:Antithrombin III