Changes in the expression of Sialyl-Lewisx, a hepatic necroinflammation-associated carbohydrate neoantigen, in human hepatocellular carcinomas

Abstract

BACKGROUND: Malignant transformation of cells is associated with the change in their carbohydrate antigens. Sialyl-Lewisx (SLEX) is a necroinflammation-associated carbohydrate antigen (NICA) of liver cells, because it is newly expressed in chronic inflammatory liver diseases. The authors addressed whether this type of carbohydrate antigen shows cancer-associated changes. METHODS: Expression of SLEX and its related structures was studied immunohistochemically using the well characterized monoclonal antibodies in 13 small and 6 advanced hepatocellular carcinomas (HCC). RESULTS: SLEX was negative in 7 small HCC, which were well differentiated histologically. Both negative and positive cells were observed in 6 other small HCC. When positive, SLEX was expressed membranously or cytoplasmically. The membrane positive HCC cells were well differentiated. Cytoplasmic expression was observed in the less differentiated cells. The SLEX-negative cells were associated with any degree of differentiation. In six advanced HCC, the expression of SLEX could also be correlated with their histologic differentiation. HCC expressed sialyl-type 2 chain N-acetyllactosamine (2-NAcLc), but not 2-NAcLc, Lewisx, and Lewisy. CONCLUSIONS: SLEX, a NICA, showed HCC-associated changes that were dependent on the levels of HCC cell differentiation. Suppression and reactivation of alpha 1-3fucosyl-transferase was a possible enzymatic basis for the observed changes.