Galectin-1 Expression in Tumors and Its Role in Cancer Cell Adhesion

Glycosylation of biological macromolecules is a common posttranslational modification. But despite its ubiquity not much is known about exact functions and mechanisms of action of particular glycosylation types on proteins and lipids. It is noted that glycosylation pattern changes during development of some malignancies [5, 13, 17]. Some of these changes were proposed for use in diagnostics of cancer [11]. Functional significance of alterations in glycosylation remains unknown. Role of glycosylation in cell physiology becomes better understandable as molecules, recognizing particular carbohydrate modifications, become known and characterized. These proteins, which have binding sites for specific monoor oligosaccharides, are named lectins. Several lectins were studied in relation to cancer, some plant lectins were shown to have antimetastatic effect [15]. There are many types of lectins with specificity to different carbohydrates and distinct properties [12]. Galectins is the family of beta-galactoside binding lectins [3]. They have common binding specificity to sugars similar in structure to lactose and all share the same protein motif (galectin signature) in carbohydrate recognition