Human Embryonal Cell Carcinoma in Nude Mice1

A lymph node metastasis specimen from a human testicular embryonal carcinoma with elements of a choriocarcinoma was successfully xenotransplanted into nude mice and maintained until the tenth animal passage. Electron microscopy of the tu mors in nude mice revealed details consistent with their epithelial origin. The xenotransplants retained the ability to synthesize human choriogonadotropic hormone during all animal passages, as evidenced by radioimmunoassay and immunoperoxidase staining techniques. The /J-humanchoriogonadotropic hormone serum level correlated significantly with the tumor volume (p < 0.05). The average amount of 0-human choriogonadotropic hor mone measured in the serum of 94 animals was 587.8 ng/ml, ranging from 5 to 4000 ng/ml. The chromosomal analysis of tumors in nude mice revealed a human chromosomal pattern with modal numbers between 55 and 60 chromosomes, and a consistent trisomy of chromosome 1.