Characterization of a human chorionic gonadotropin-producing testicular choriocarcinoma cell line

A testicular choriocarcinoma cell line designated JHTK-1 was established in vitro from a mixed germ cell tumor xenografted into nude mice, and may prove to be the first human choriocarcinoma cell line of testicular origin in long-term culture. The cells have been kept in culture for three years and produce human chorionic gonadotropin persistently. The chromosome number distribution ranged from tetraploidy to septaploidy, and trypsin G-band karyotyping showed that all the chromosomes were of human origin. Dibutyryl cyclic adenosine monophosphate at a concentration of 1 mM caused more than 15-fold stimulation of human chorionic gonadotropin secretion with morphological alteration in JHTK-1 cells. This suggests that dibutyryl cyclic adenosine monophosphate induces the differentiation of cytotrophoblastic cells into syncytiotrophoblastic cells among JHTK-1 cells. When JHTK-1 cells were heterotransplanted into the subcutis of BALB/c nude mice, large cystic tumors were produced with histological characteristics similar to choriocarcinoma.