Glycoproteomic Discovery of Serological Biomarker Candidates for HCV/HBV Infection-Associated Liver Fibrosis and Hepatocellular Carcinoma

TLDR

We previously proposed a high‑throughput strategy to discover serological biomarker candidates of cancer, focusing on glycoproteins specifically expressed in the target tissues and carrying glycans associated with carcinogenesis. Here, we examined the effectiveness of this strategy for identifying biomarkers to assess liver fibrosis progression and for early detection of hepatocellular carcinoma (HCC). Using lectin array analyses of hepatoma cell line culture media, we captured fucosylated and branched glycopeptides from digests of culture media proteins and sera from HCC patients with liver cirrhosis, identified glycoproteins by IGOT‑LC‑MS, and selected 21 candidates from 744 AAL‑bound glycoproteins based on serum abundance, liver‑specific expression, and antibody availability. All selected candidates showed increased AAL‑reactivity in sera of HCC patients versus healthy volunteers, indicating that the glycoproteomic strategy effectively identifies multiple glyco‑biomarker candidates in a high‑throughput manner. Reference: FEBS J.

Abstract

We previously proposed a high-throughput strategy to discover serological biomarker candidates of cancer. This strategy focuses on a series of candidate glycoproteins that are specifically expressed in the original tissues (cells) of the target cancer and that carry glycan structures associated with carcinogenesis [Narimatsu, H., et al. FEBS J.2010, 277(1), 95-105]. Here, we examined the effectiveness of our strategy in identifying biomarkers to assess progression of liver fibrosis and for the early detection of hepatocellular carcinoma (HCC). On the basis of the results of lectin array analyses in culture media of hepatoma cell lines, we captured glycopeptides carrying AAL-ligands (fucosylated glycans) or DSA-ligands (branched glycans) from digests of culture media proteins and sera from HCC patients with a background of liver cirrhosis (LC). Glycoproteins were identified by the IGOT-LC-MS method. In all, 21 candidates were selected from 744 AAL-bound glycoproteins for further verification according to (i) their abundance in serum, (ii) their specific expression in liver, and (iii) the availability of antibodies to the glycoproteins. All selected candidates showed enhancement of AAL-reactivity in sera of HCC patients compared with that of healthy volunteers (HV). These results indicate that our glycoproteomic strategy is effective for identifying multiple glyco-biomarker candidates in a high-throughput manner.