Under various conditions of culture and carcinogen treatment, the transformation of liver cells by 3'-methyl-4-dimethylaminoazobenzene (3'-Me-DAB) was studied. Primary liver cell (PLC) cultures from adult male rats and co-cultures with PLCs of ARL-D8 cells of a liver epithelial-like clear cell line from adult female rats were treated with 0.24 mM 3'-Me-DAB for 6 days. Four of 8 carcinogen-treated PLC cultures contained cells with marker chromosomes, and 3 of the 8 cultures contained gamma-glutamyltranspeptidase (GGT)-positive cells. Three of 5 carcinogen-treated co-cultures contained cells with marker chromosomes, and 2 of the 5 co-cultures contained GGT-positive cells. Pure cultures of ARL-D8 cells were treated for 6 or 12 days with 3'-Me-DAB (0.24 mM)-containing-medium perfused through the liver of adult male rats in situ. In the 6-day treatment, none of 5 carcinogen-treated cultures showed chromosomal abnormality or cytochemically exhibited GGT activity. However, in the 12-day treatment, 2 of the 5 carcinogen-treated cultures contained cells with marker chromosomes, and 2 of the 5 cultures contained GGT-positive cells. None of the control cultures exhibited chromosomal abnormality or GGT-positive cells. In summary, transformation markers increased in ARL-D8 cells when they were co-cultured with PLCs.</p
