Glycosylation in Cancer: Enzymatic Basis for Alterations in N-Glycan Branching

Abstract

Aberrant glycosylation is the basic phenomenon found in almost all types of experimental and clinical cancer tissues and/or cell lines, and many glycosyl epitopes are known to constitute so-called tumor-associated carbohydrate antigens (TACAs). Many lines of evidence suggest that these cancer-related glycosyl epitopes play functional roles in a variety of pathophysiologic events in cancer, such as cell metastasis and invasion, apart from their potential values as diagnostic and/or prognostic glyco-biomarkers. This chapter describes a brief summary on the aberrant glycosylation in cancer, the related glycosyltransferases, and their roles in cancer development and progression. The chapter focuses on the glycosyltransferases responsible for N-glycan branching; those include N-acetylglucosaminyltransferase (GnT)-III, GnT-IV, and GnT-V and fucosyltransferase (FUT) 8.