Changes in N-linked glycosylation are known to occur during the development of cancer. For example, increased branching of oligosaccharides has been associated with metastasis and has been correlated to tumor progression in human cancers of the breast, colon and melanomas. Increases in core fucosylation have also been associated with the development of hepatocellular carcinoma (HCC). Chronic infection with the hepatitis B virus is associated with more than 55% of all cases of hepatocellular carcinoma. We show here that increased levels of core fucosylation can be observed via glycan analysis of total serum and are associated with the development of HCC. In a blinded study, the serum glycoproteins derived from people diagnosed with HBV induced liver cancer were found to possess a dramatically higher level of fucosylation. This change occurs on both immunoglobulin molecules and on other serum glycoproteins. Targeted glycoproteomic analysis was used to identify those glycoproteins that are hyperfucosylated in cancer. In total, 19 proteins were found to be hyperfucosylated in cancer. The potential of these proteins as biomarkers of cancer is discussed.

Changes in N-linked glycosylation are known to occur during the development of cancer. For example, we have previously reported changes in N-linked glycosylation that occur with the development of hepatocellular carcinoma (HCC) and, through the use of glycoproteomics, identified many of those proteins containing altered glycan structures. To advance these studies and further explore the glycoproteome, we performed N-linked glycan analysis from serum samples depleted of the major acute phase proteins, followed by targeted lectin extraction of those proteins containing changes in glycosylation. Using this method, changes in glycosylation, specifically increased amounts of core and outer arm fucosylation were observed in the depleted samples. The identities of those proteins containing core and outer arm fucose were identified in the serum patients with HCC. The usefulness of some of these proteins in the diagnosis of HCC was determined through the analysis of over 300 patient samples using a high-throughput plate based approach. Greatest performance was achieved with fucosylated hemopexin, which had an AUROC of 0.9515 with an optimal sensitivity of 92% and a specificity of 92%.

Hepatitis B and C viruses are major causative agents of liver fibrosis, cirrhosis, and liver cancer. Using comparative glycoproteomics, we identified a glycoprotein that is altered both in amount and in glycosylation as a function of liver fibrosis and cirrhosis. Specifically, this altered glycoprotein is an immunoglobulin G (IgG) molecule reactive to the heterophilic alpha-Gal epitope [Gal␣-1-3Gal␤1-(3)4GlcNAc-R]. While similar changes in glycosylation have been observed in several autoimmune diseases, the specific immunoglobulins and their antigen recognition profiles were not determined. Thus, we provide the first report identifying the specific antigenic recognition profile of an immunoglobulin molecule containing altered glycosylation as a function of liver disease. This change in glycosylation allowed increased reactivity with several fucose binding lectins and permitted the development of a plate-based assay to measure this change. Increased lectin reactivity was observed in 100% of the more than 200 individuals with stage III or greater fibrosis and appeared to be correlated with the degree of fibrosis. The reason for the alteration in the glycosylation of anti-Gal IgG is currently unclear but may be related to the natural history of the disease and may be useful in the noninvasive detection of fibrosis and cirrhosis.