ABSTRACT
Glycoproteins on cell surfaces and in secretions are heterogeneously N-and O-glycosylated, with mucins being extremely highly glycosylated, carrying a multitude of different O-glycan structures. Not only the expression of speciˆc proteins but also the patterns of their glycans are usually altered in cancer and can differ between tissue origin, cell type, progression of tumors, stage of disease, and stage and site of metastasis. There are no rules that apply to all cancer cells, and often the expression
8.1 Introduction to Tumor Glycosylation ............................................................ 177 8.2 Functions of Glycoprotein-Bound Glycans .................................................. 178
8.2.1 Role of Glycans in Glycoprotein Functions ...................................... 178 8.2.2 Adhesion and Invasion of Tumor Cells ............................................. 179 8.2.3 Selectins in Cancer ........................................................................... 180 8.2.4 Galectins ........................................................................................... 181
8.3 Cancer-Speciˆc Glycan Structures and Markers .......................................... 182 8.3.1 O-Glycan Structures in Cancer ........................................................ 183 8.3.2 Mucins in Cancer .............................................................................. 184 8.3.3 O-GlcNAc in Cancer ........................................................................ 186 8.3.4 N-Glycan Structures in Cancer ......................................................... 187
8.4 Biosynthesis and Glycodynamics of Tumor-Associated Structures ............. 189 8.4.1 General Mechanisms of Glycoprotein Biosynthesis ......................... 189 8.4.2 Role of Aberrant O-Glycosylation Pathways in Cancer ................... 190 8.4.3 Synthesis of N-Glycans in Cancer Cells ........................................... 196
8.5 Development of Cancer Diagnosis and Therapy Targeting Glycosylation ................................................................................................ 198
8.5.1 Tumor Vaccines ................................................................................ 198 8.5.2 Glycosylation Inhibitors .................................................................... 199
8.6 Conclusions and Future Applications in Cancer Research ...........................202 Acknowledgments ..................................................................................................203 References ..............................................................................................................203
