Glycosylation in Cancer

Structural alterations of the glycan chains attached to glycoproteins and glycolipids are present in all types of malignomas investigated to date, including adenocarcinomas, sarcomas and haematological malignancies. They occur in humans as well as in animals including experimental models of malignancy, regardless of the type, cause, or stage of the tumour. The biochemical and genomic characterization of the enzymatic machineries involved in glycan biosynthesis in cancer cells shows that tumour-associated glycosylation changes are a critical part of tumour initiation and progression. Experimental studies and epidemiological findings give clear evidence that tumour-associated glycans bear functional significance in the invasive and metastatic growth of malignancies, for immunological tumour defence and, hence, influence the clinical outcome and the prognosis of cancer patients. Tumour-associated glycan changes are, moreover, targets for new pharmacological and immunological therapy methods and serve as important clinical biomarkers for diagnosis, particularly for monitoring disease progression and therapeutic efficacy. This chapter provides an overview of the major types of changes of glycosylation, genetic and biochemical mechanisms contributing to cancer-associated glycosylation, functional consequences for tumour growth and the clinical significance in cancer diagnosis, monitoring and treatment.