Thomsen–Friedenreich antigen
Thomsen–Friedenreich antigen is a disaccharide. It is usually present on cell surfaces in a cryptic form covered by N-Acetylneuraminic acid moieties, and is released into circulation in many different cancers.Abstract
The Thomsen–Friedenreich antigen represents a tumor-associated molecule, which is assumed to be one of the few chemically well-defined antigens with a proven association with malignancy. In order to analyze the role of the carbohydrate structure Gal-GalNAc for gastrointestinal tumors, Balb/c mice with MCF-7 breast tumor cells were immunized, together with synthetic Gal-GalNAc linked to a BSA carrier. One monoclonal antibody was established that recognizes the Thomsen–Friedenreich antigen according to the biochemical and serological analysis presented here.
In contrast to studies performed in the past, immunohistochemical results using the antibody 82-A6 did not exhibit a reactivity clearly restricted to tumors. Preliminary biochemical analysis revealed that the T-determinant is detectable in the high-molecular weight range, suggesting that the Gal-GalNAc epitope is found on mucin-like glycoproteins. Tumor restriction of the Thomsen–Friedenreich antigen may therefore be determined either by the protein backbone or by the beta-glycosidic linkage of the carbohydrate structure to the protein.
