Virchows Arch [Cell Pathol] (1983) 43:241-251 g' chtmsArch/vB 9 Springer-Verlag 1983 Male murine embryonal carcinoma cell line selectively metastatic to the ovaries and adrenals Niles FOX,1'2 Luis DeSouza, 1 Daniela Simon, 2 and Ivan Damjanov 1 1 Department of Pathology and Laboratory Medicine, Hahnemann University, Philadelphia, Pennsylvania 19102 USA 2 Wistar Institute, Philadelphia, Pennsylvania 19104 Summary. Developmentally pluripotent embryonal carcinoma cells were isolated from chromosomally male embryo-derived teratocarcinoma and adapted to in vitro growth without a feeder layer. The uncloned original cell line as well as clones derived from it have a tendency to selectively localize to the ovaries and adrenals upon intravenous injection into adult female mice, but only to the adrenals when injected into male mice. The overall take of injected tumor cells was lower in males and the tumors formed slower in males than in females. These findings suggest that the growth of this karyotypically male embryonal carcinoma could be under hormonal regulation. Key words: Teratocarcinoma - Embryonal carcinoma - Metastasis Introduction Murine teratocarcinomas resemble the equivalent human tumors both bio- logically and morphologically (Solter and Damjanov 1979). However, in contrast to most human teratocarcinomas which metastasize early in the course of clinically overt disease, the murine tumors are only locally invasive and spontaneously metastasizing teratocarcinomas appear to be extremely uncommon. Metastatic growth of murine teratocarcinoma cells can be achieved by intravenous injection of single embryonal carcinoma (EC) cells, the stem cells of teratocarcinoma or embryoid bodies (Ishikawa 1979). The tumor cells injected intravenously usually localize in the lungs and only exception- ally form solid tumors in other organs. Teratocarcinoma stem cell lines which selectively invade the spleen (Auerbach 1977) or the ovaries (Kahan 1979) have also been isolated, indicating that these tumor cells could be used to study the factors determining the selective homing of metastatic cells to various organs. Offprint requests to: I. Damjanov at the above address