Transformation of feline embryo cells in culture by a chemical carcinogen.

A feline embryo cell line was treated in vitro with various levels of 7,12-dimethylbenz[a]anthracene (DMBA) or dimethyl sulfoxide (control). Repeat treatment of DMBA only induced in vitro transformation of feline embryo cells following clonal growth and selection. The morphologically altered cells formed large cell aggregates and grew in this aggregate form when suspended in liquid growth medium above an agar base, formed colonies in soft agar, and grew to high saturation densities. However, no progressively growing tumors were produced when cells were inoculated into nude athymic mice. The transformed lines were negative for feline oncornavirus-associated cell membrane antigen (FOCMA).