Monoclonal Antibodies Against Human Germ Cell Tumors: Usefulness as Tumor Markers and Differentiation Markers

Establishment of monoclonal antibodies against human germ cell tumors which detected cell surface antigens, 2A2 and 2G10 (subclass; IgM) are described. Distributions of these antigens in human tumors were studied immunohisto-chemically. They were expressed on immature endodermal components often seen in yolk sac tumors but not on the other solid tumors in childhood. Regarding their specificities on human germ cell tumor, we have established an ELISA system to detect these antigens from patient's sera. In normal and fetal tissue, on the other hand, they showed quite different distributions. In the kidney, for example, 2A2 and 2G10 were present on collecting tubules and proximal/distal tubules respectively which were already observed in fetal kidney, gestational ages 10 weeks. These results indicate the usefulness of these antibodies as the markers for human germ cell tumors and also for somatic cell differentiation.