Increased levels of tetra-antennary N-linked glycan but not core fucosylation are associated with hepatocellular carcinoma tissue.

Abstract

Alterations in glycosylation have long been associated with the development of cancer. In the case of primary hepatocellular carcinoma (HCC), one alteration that has often been associated is increased amounts of fucose attached to the N-glycans of serum proteins secreted by the liver. In an effort to determine the origin of this increased fucosylation, we have conducted N-linked glycan analysis of HCC tissue, the surrounding nontumor tissue, and compared this to tissue from a nondiseased adult liver. Surprisingly, no difference in the level of fucosylation was observed from the three donor groups, suggesting that the increased levels of fucosylation observed in serum of those with HCC is not the result of increased synthesis of fucosylated proteins in the cancer tissue. On the other hand, increased levels of a tetra-antennary glycan were observed in the HCC tissue as compared with the surrounding tissue or to the nondiseased livers. This represents, to our knowledge, one of the first reports associating increased levels of branching with the development of HCC. The identification of increased levels of tetra-antennary glycan on liver tumor tissue, as opposed to adjacent or nondiseased tissue may lead to improved detection of HCC.