Use of targeted glycoproteomics to identify serum glycoproteins that correlate with liver cancer in woodchucks and humans

Abstract

Chronic infection with hepatitis B virus (HBV) is associated with the majority of hepatocellular carcinoma (HCC).The diagnosis of HCC is usually made in the late stages of the disease, when treatment options are limited and prognosis is poor. We therefore have developed a method of glycoproteomic analysis in an attempt to discover serum markers that can assist in the early detection of HBV-induced liver cancer. Briefly, a comparative method for analysis of oligosaccharides released from serum glycoproteins and for recovery and identification of proteins with aberrant glycosylation, as a function of cancer diagnosis, is described. The model we have used is the woodchuck (Marmota monax), which shares similarities in the glycosylation pattern associated with liver proteins in human HCC. In this report, we show that woodchucks diagnosed with HCC have dramatically higher levels of serumassociated core ␣-1,6-linked fucose, as compared with woodchucks without a diagnosis of HCC. The coupling of this methodology with 2D gel proteomics has permitted the identification of several glycoproteins with altered glycosylation as a function of cancer. One such glycoprotein, Golgi Protein 73 (GP73), was found to be elevated and hyperfucosylated in animals with HCC. Further, the study showed GP73 to be elevated in the serum of people with a diagnosis of HCC, providing a validation of our approach. The potential of this technology for biomarker discovery and the implications of increased levels of GP73 in liver cancer are discussed.glycomics ͉ hepatitis B virus ͉ hepatocellular carcinoma ͉ proteomics

Prognostic Value of Serum AFP, AFP-L3, and GP73 in Monitoring Short-term Treatment Response and Recurrence of Hepatocellular Carcinoma after Radiofrequency Ablation

“…GP73 was originally described as a resident Golgi type II transmembrane protein expressed primarily in epithelial cells of many human tissues. GP73 antigen expression is barely detectable in healthy subjects, but it is elevated modestly in virus carriers, moderately in patients with cirrhosis, and dramatically in patients with HCC (Block et al, 2005). Mao et al (Mao et al, 2010) compared serum GP73 and AFP levels in 4217 human subjects in a multicenter study in 2010, finding that the sensitivity and specificity of GP73 level for the detection of HCC were 74.6% and 97.4%, respectively, significantly higher than the corresponding values for AFP level.…”

Bladder Cancer Associated Glycoprotein Signatures Revealed by Urinary Proteomic Profiling

“…27 Accordingly, the alteration in protein glycosylation which occurs through varying the heterogeneity of glycosylation sites or changing the glycan structure of proteins on the cell surface and in body fluids has been shown to correlate with the development of numerous disease states, including cancer. 28 Indeed, many clinical biomarkers and therapeutic targets in cancer are glycoproteins 29 such as CA125 in ovarian cancer, Her2/neu in breast cancer, and prostatespecific antigen (PSA) in prostate cancer. PSA is one of the best characterized examples of a secreted glycoprotein used in cancer diagnostics, and its glycoforms have been described.…”

Serum Golgi Phosphoprotein 2 level: A better marker than alpha-fetoprotein for diagnosing early hepatocellular carcinoma

“…3 A recent study showed that GOLPH2 was detected in human serum, and it was found to be elevated in the serum and tissue in the woodchuck model of HCC in comparison with the nonneoplastic liver. 4 Thus, GOLPH2 may be a potential marker for the early detection of HCC.…”