ABSTRACT
The sugar chains of complex carbohydrates are generally thought to play a role in a variety of biological and pathophysiological processes such as adhesion, sorting, cell growth, differentiation and carcinogenesis. Cell surface membrane glycoproteins undergo cancer-associated changes with respect to their carbohydrate moieties and the structural changes may occur as a result of enhancement of glycosyltransferases or glycosidases which are associated with the biosynthetic or degradation processes, respectively. In most of cases, however, the structural changes in glycoproteins in cancer tissues are due to the activation of glycosyltransferases.
