Histochemically demonstrable changes in cell surface carbohydrates of human germ cell tumors

Cell surface carbohydrate chains of human germ cell tumors were investigated histochemically using peanut agglutinin (PNA), Dolichos biflorus agglutinin (DBA), Ulex europaeus agglutinin I (UEA-1), and anti-I-(Ma) antibody. Of 16 cases of embryonal carcinoma in adult testis, peanut agglutinin, a lectin specific for terminal beta-galactosyl residues, bound to the surface of tumor cells in 11 cases, D. biflorus agglutinin, a lectin specific for terminal alpha-N-acetyl galactosamine residues, in 10, and U. europaeus agglutinin, a lectin specific for terminal alpha-L-fucosyl residues in 7. I-(Ma) antigen, a branched carbohydrate chain composed of three N-acetyl lactosamine units, was found in 12 cases as well. The cell surface of tubular or organoid architecture tended to be positive for some of these four reagents, whereas that of a papillary pattern tended to be negative. All yolk sac tumors (three in adult testis, 10 in infantile testis, and four in ovary) were positive for peanut and U. europaeus agglutinins and anti-I-(Ma) antibody but were negative for D. biflorus agglutinin. Seventeen of 18 seminomas (in adult testis) and one dysgerminoma (in ovary) did not react with these four reagents. Four choriocarcinomas (three in testis and one in ovary) were not positive for any of them either. In 10 cases of immature teratoma, the appearance of the binding sites to these lectins and antibody depended on the direction of differentiation and the degree of maturity. These findings suggest that carbohydrate chains of human germ cell tumors change greatly in the process of differentiation from embryonal carcinoma cells to somatic cell (teratoid) component or yolk sac carcinoma component, and that histochemical detection of the binding sites described may assist in the classification of germ cell tumors, in spite of the lack of precise knowledge about the biologic role of cell surface carbohydrates.