A comparison of expression of neoplastic potential of carcinogen-transformed human fibroblasts in nude mice and in chick embryonic skin.

Human foreskin fibroblasts transformed by representative chemicals from five different classes of chemical carcinogens, some requiring enzymatic activation and direct acting carcinogens, produced cell populations that exhibited anchorage-independent growth and expression of neoplastic potential in either nude mice or chick-embryonic skin (CES). There is a high degree of correlation between tumor incidence and invasiveness of CES. The unique feature of CES is the rapidity of expression of cellular neoplasia and interpretation of the simulated tumor in 4 d as a simulated fibrosarcoma. This method represents a system that can be used to evaluate human carcinogens in vitro in 6 to 10 wk.