Establishment and characterization of a new clonal strain derived from human benign gastric teratoma.

Various kinds of cell-types such as squamous epithelial cells, columnar epithelial cells, sarcomatous cells and fibroblast-like cells proliferated in vitro during the initial period of the primary culture from the human benign gastric tridermal teratoma. The fibroblast-like cells designated HOGT clonal strain were established from a single cell of primary cultures. The HOGT clonal strain grew well and 70 serial passages were successively carried out within 17 months. Although the HOGT cells are karyologically normal, when transplanted into the subcutis of nude mice they produced a benign tridermal teratoma. The results obtained from cell culture and heterotransplantation of teratoma strain enabled us to hypothesize that the graft (tridermal teratoma) in mice may arise from a pluripotent stem cell.