Carcinogenesis in the mammary gland is thought to involve carcinogen-induced initiation in mammary epithelial cells. Recent experiments have demonstrated that the mammary stroma can be a target of carcinogenic agents, which results in the stroma positively affecting carcinogenesis. To determine whether the stroma or epithelium is the primary target in chemically induced mouse mammary tumorigene...

Treatment of Chironomus polytene chromosomes with the ultimate carcinogen benzo[a]pyrene diol epoxide I or in vivo administration of the parent hydrocarbon to larvae indicates that the carcinogen interacts with the genome in a nonrandom manner. Visualization of the carcinogen-DNA binding sites by immunofluorescence reveals that, in vivo, some sites are preferentially modified. The combined effe...

Inducers of phase II detoxifying enzymes have been studied as chemopreventive agents for a variety of cancers. Phase II detoxifying enzymes may play a significant role in preventing carcinogen-induced colon cancer at the initiation and post-initiation stage, but the contribution of NAD(P) H:quinone oxidoreductase 1 (NQO1) to this effect remains unclear. Using the carcinogen-induced colon cancer...

The effect of hepatocarcinogen administration in vivo on the induction of pleiotropic drug resistance was studied in primary monolayer cultures of adult rat hepatocytes using a cytotoxicity assay in vitro. Dietary 2-acetylaminofluorene, 3'-methyl-4-dimethylaminoazobenzene, aflatoxin B1, ethionine, and diethylnitrosamine rapidly induced resistance to doses of Adriamycin, methotrexate, cyclohexim...