Conditions Permitting Solid Tumor Formation of Teratocarcinoma Cells in Allogeneic Mice

In this report, the growth capacity of murine ascitic teratocarcinomas (embryoid bodies, EBs) was studied in certain strains of allogeneic mice. When EB was intravenously injected into Balb/c mice, various types of tumor colonies were formed with various types of differentiated tissues in the lung, as in the case of syngeneic 129/Sv mice. Tumor colonies in the abdomen of Balb/c and other allogeneic mice formed by the intraperitoneal injection of EB, however, contained merely undifferentiated embryonal carcinoma cells (EC cells) and sometimes some primitive tissues, too. Analysis of lung colonies (LCs) from EBs in Balb/c mice indicated that EC cells are a potent target for being rejected but they can escape this rejection by differentiating into various types of tissues cells.