Abstract 5569: N-glycosylation in cultured cells and hepatocellular carcinoma

Purpose: Incidence of hepatocellular cancer (HCC) continues to increase primarily due to hepatitis C viral (HCV) infection. Prognosis and survival of patients is highly affected by the disease stage at the time of diagnosis. Our mass spectrometric study evaluated N-glycans during the progression of HCV infection to cancer. Glycosylation of immunoglobulins and other serum proteins was examined in cultured cells and in serum of patients with hepatocellular carcinoma. Methods and Results: Protein associated N-glycans were released with PNGaseF and analyzed by MALDI-TOF/TOF analysis following solid phase permethylation. Analysis of less than 0.04 ml of serum led to relative quantification of 70 N-glycan structures. Immunoaffinity isolation of immunoglobulins and other serum proteins allowed us to study protein-specific glycosylation. Progression of HCV infection to HCC was strongly associated with changes in the glycosylation of immunoglobulins. In a pilot case-control study (25 HCC cases and 35 controls), N-glycosylation of eight glycans was significantly different in HCC compared to chronic liver disease controls. The glycosylation of serum proteins was further compared to the proteins secreted by the Huh-7.5 cell line. Conclusion: This study demonstrates mass spectrometric analysis of 70 N-glycans in serum, cultured cells, and isolated proteins. Our results show that the analysis of permethylated N-glycans helps to define changes associated with the progression of HCV infection to HCC. Evaluation of glycan abundance suggests the potential to use glycans for the detection of liver disease. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5569.