CHANGES IN THE EXPRESSION OF SIALYL-LEWIS(X), A HEPATIC NECROINFLAMMATION-ASSOCIATED CARBOHYDRATE NEOANTIGEN, IN HUMAN HEPATOCELLULAR CARCINOMAS

Background. Malignant transformation of cells is associated with the c hange in their carbohydrate antigens. Sialyl-Lewis(x) (SLEX) is a necr oinflammation-associated carbohydrate antigen (NICA) of liver cells, b ecause it is newly expressed in chronic inflammatory liver diseases. T he authors addressed whether this type of carbohydrate antigen shows c ancer-associated changes. Methods. Expression of SLEX and its related structures was studied immunohistochemically using the well characteri zed monoclonal antibodies in 13 small and 6 advanced hepatocellular ca rcinomas (HCC). Results. SLEX was negative in 7 small HCC, which were well differentiated histologically. Both negative and positive cells w ere observed in 6 other small HCC. When positive, SLEX was expressed m embranously or cytoplasmically. The membrane positive HCC cells were w ell differentiated. Cytoplasmic expression was observed in the less di fferentiated cells. The SLEX-negative cells were associated with any d egree of differentiation. In six advanced HCC, the expression of SLEX could also be correlated with their histologic differentiation. HCC ex pressed sialyl-type 2 chain N-acetyllactosamine (2-NAcLc), but not 2-N AcLc, Lewis(x), and Lewis(y). Conclusions. SLEX, a NICA, showed HCC-as sociated changes that were dependent on the levels of HCC cell differe ntiation. Suppression and reactivation of alpha1-3fucosyl-transferase was a possible enzymatic basis for the observed changes.