Transformation of rat embryo cells in vitro by chemical carcinogens.

The in vitro transformation of mouse and hamster cells by chemical carcinogens has been described and well established. (1—5, 8, 13, 19, 20). Most in vitro transformations of cell cultures by chemical carcinogens yielded sarcomas upon reinsertion into syngeneic hosts. Transformation of rat embryo cells by 4-nitroquinoline 1-oxide (15) and fluorenylhydroxamic acids (7) has been reported recently. However, there is no evidence for the transformation of rat embryo cells by polycyclic aromatic hydrocarbons. This communication re ports results of experiments showing that rat embryo cells can be transformed in vitro by polycyclic aromatic hydrocarbons and that these transformed cells produce tumors when injected into newborn rats. 4-day intervals. For the 1st 4 subcultures, the cells were maintained in Eagle's minimum essential medium with 0.1 mM