[Characteristics of the growth and differentiation of teratocarcinoma OC15S1 in syngeneic and allogeneic mice].

Ascites teratocarcinoma OC15S1 represented by embryoid bodies contains two populations of embryocarcinoma cells with different rates of proliferation and levels of differentiation: diffusely dispersed cells (mitotic cycle 11 h, isotope exchange index 32.7%) and cavity-forming cells (14 h and 23.9%, respectively). Upon transplantation of embryoid bodies to allogeneic C57BL mice the growth of teratocarcinoma is inhibited: ascites tumor does not transform to solid; the number of embryoid bodies is 40 times less than in syngeneic mice; the number of necrotic embryoid bodies increases; the animals do not die. Retransplantation of teratocarcinoma cells from allogeneic C57BL mice to syngeneic 129 mice has demonstrated the presence of stem embryocarcinoma cells which retain their oncogenic properties and the mode of differentiation.