Glycomic Analysis of Cancer

Abstract

Remarkable alterations in oligosaccharide structures are associated with many human diseases, including cancers. Numerous clinicopathological and biochemical studies have suggested the involvement of aberrant glycosylation in cancer malignancy, such as metastasis and invasion. Furthermore, altered carbohydrate determinants, including tumor-associated carbohydrate antigens such as SLea (CA19-9), have been utilized as useful tumor markers for the diagnosis of cancer. Cancer glycomic analysis (i.e., precise and comprehensive analysis of altered oligosaccharides in cancer tissues and sera) is a widely used tool for (1) investigating the involvement of glycosylation in cancer malignancy and (2) discovering novel carbohydrate tumor marker candidates. Comprehensive clinico-glycomic studies of glycosphingolipids of colorectal cancers have revealed specific alterations related to malignant transformation, as well as characteristic alterations associated with clinical features. Glycomic analyses of colorectal cancers and pancreatic cancers revealed the presence of two kinds of novel fucogangliosides, sialylated type1H (Lewis-negative specific antigen) and sialylated type2H, both of which are isomers of sialyl Lex and sialyl Lea. The accumulation of free oligosaccharides in human cancers has been elucidated. Free Neu5Ac-containing complex-type N-glycans accumulated in pancreatic cancers. In addition to these free oligosaccharides, free KDN-containing complex-type N-glycans accumulated in prostate cancers. N-linked and O-linked glycans have also been targets for cancer glycomics. In particular, extensive studies of serum glycomic analyses have been performed to find novel glycan cancer biomarker utilizing newly developed high-throughput platform technologies. It is anticipated that these cancer glycomic studies will lead to the discovery of glycan biomarker or therapy targets for cancers.