Aberrant Glycosphingolipid Expression and Mambrane Organization in Tumor Cells : Consequences on Tumor-Host Interactions

More than 20 years ago [1], the pioneering work of Dr. Sen-itiroh Hakomori formed the basis for the concept that aberrant glycosylation is a general feature of human cancer. The term "aberrant glycosylation" describes the altered expression of oligosaccharide epitopes associated with both glycolipid and glycoprotein antigens in human cancer. This event is the consequence of at least two different metabolic mechanisms: (1) the impairment of specific glycosylation steps ("incomplete synthesis") and (2) the transcriptional induction of genes encoding for glycosyltransferases or carbohydrate transporters ("neosynthesis") [2]. Both mechanisms contribute to the accumulation of antigen-carrying tumor-associated epitopes that were originally defined by their ability to raise the production of specific antibodies and subsequently characterized on the basis of their molecular structure. The discovery of oligosaccharide tumor-associated antigens provided useful diagnostic tools and opened the field of tumor glycobiology, which developed tremendously in the following decades.