Establishment and characteristics of a new human choriocarcinoma cell line and its production of tumor markers]

A human gestational uterine choriocarcinoma cell line (NJG) was established in vitro. The NJG cell line had been subcultured more than 73 times over 7 years. The cells consisted mainly of Langhans-like cells, while multinucleated cells were occasionally seen. The cells grew in a monolayered sheet, showing a tendency to pile up, with the population doubling in 80 hrs. Electron-microscopically, desmosomes were characteristically observed, which suggested that the cultured cells were of epithelial origin. Chromosomal analysis revealed aneuploidy with a hypertriploid mode and 4 marker chromosomes. Immunocyto- and-histochemical staining for tumor markers of the cultured cells and the transplanted tumors to nude mice showed close similarity. SP1 was occasionally demonstrated and PP5 was faintly stained only in the heterotransplanted tumors, although PP10 and PP12 were not demonstrable. HCG was localized not only in syncytial cells, but also in Langhans cells, and syncytial cells without hCG were also observed in the tumors. A single cell clone was also established from the original NJG cells by a limiting dilution method. The heterotransplanted tumor consisted of Langhans and syncytial cells, indicating that both cells originated from the same cell.