EXPRESSION OF LEWIS(X) SUGAR STRUCTURE IN THE LIVER METASTASIS OF MOUSE COLON-CARCINOMA (COLON-26) CELLS

Immunohistochemical aspects of the process of experimentally induced metastasis were examined by light and electron microscopy employing a series of labeled carbohydrate-specific monoclonal antibodies as probes. Liver metastasis was induced by injecting mouse colon carcinoma cell (colon 26) into the spleen of Balb/c mice. Labeled anti-Lewis(x) (Le(x)) antibody stained the metastasized colon 26 cells strongly compared with the heterogeneous and faint staining in non-metastasized tumor foci in the spleen or in the subcutaneous space. Other antibodies having specificities for Lewis-related antigens other than Le(x), e.g. those against Le(y), Le(a), Le(b), sialyl Lex and sialyl Le(a), did not show any differences in binding between metastasized cells and non-metastasized tumor foci. Immunoelectron microscopy revealed the expression of Le(x)-carbohydrate in the plasma membranes as well as in the intercellular spaces of metastasized colon 26 cells in the liver. Based on these results, it is likely that sugar chains containing the Le(x)-carbohydrate structure are involved in the interactions between colon 26 cells and hepatic cells during the process of liver metastasis.