Polysaccharides In Cancer

Abstract

Polysaccharides, both free and associated with other body constituents, form a significant part of living cell. The diverse functions suggested for the polysaccharides range from their being an energy source (glycogen), blood group determinants (blood group polysaccharides), anticoagulants (heparins), structural material of ground substance and extracellular cement (mucoproteins), and secretions (mucoids) to being the components of certain hormones (glycoprotein hormones). A survey of literature has indicated that many of these polysaccharides are present in cancer tissues, animal as well as human. It is also found that certain transplantable animal hepatomas possess remarkable capacity to form and store glycogen. This chapter focuses on the homopolysaccharide-glycogen and discusses its general characteristics and isolation processes. It covers the detection of glycogen by histochemical, electron, microscopic, and radioautographic means, along with the biosynthesis of glycogen. It also outlines the research made in this field regarding the presence of glycogen in certain human tumors, including brain tumor, bone tumor, breast tumor, carcinoma of the bladder, and cancer of the cervix. The chapter also lists the effect of various cancer-causing agents on glycogen metabolism in liver, inlcuding X-irradiation, nitrosamines, ethionine, carbon tetrachloride, azo dyes, and aminofluorenes, and various studies that were conducted on glycogen in certain transplantable tumors. It studies the chemical composition and biosynthesis of major mucopolysaccharides—that is, heparin, hyaluronic acid, and chondroitin sulphates, and examines the effect of mucopolysaccharides on tumor growth.