Viability of polyploid organisms in lower vertebrates including fish provides an additional tool to investigate genetic mechanisms of neoplastic transformation caused by carcinogens. Here we present data on differential sensitivity of diploid and triploid zebrafish (Danio rerio) to N-nitrosodimethylamine (NDMA) induced hepatocarcinogenesis. The effect of the carcinogen was studied in 100 diploi...

The effects of dietary unsaturated and saturated fats on chemically induced colon carcinogenesis were examined in male Donryu rats. The rats were fed two types of semipurified diets consisting of 5% linoleic acid or 4.7% stearic acid plus 0.3% essential fatty acid as dietary fats. The rats were treated with azoxymethane (7.4 mg/kg body weight) s.c. once a week for 11 weeks and sacrificed 15 wee...

Antibodies have been developed against a wide array of carcinogen-DNA adducts as well as UV-damaged or oxidized bases. Their sensitivity for the detection of DNA damage in humans has been demonstrated in numerous studies of occupational, dietary, environmental, clinical, and lifestyle exposures. Unlike the postlabeling assay that can detect multiple hydrophobic carcinogen adducts in a single ex...

Because of a possible etiologic link between mutations and carcinogenesis, we compared fibroblasts derived from skin biopsies of several patients with hereditary cutaneous malignant melanoma and the dysplastic nevus syndrome for sensitivity to the mutagenic and/or cytotoxic effect of broad-spectrum simulated sunlight and of a UV mimetic carcinogen, 4-nitroquinoline 1-oxide (4NQO). The genetic m...

A method has been developed to assess the metabolism and mutagenic activation of carcinogens using human and rodent hepatocytes in vitro. A slicing technique which was especially useful for nonperfusable biopsy and resected surgical human liver tissue was used to prepare the hepatocytes. Metabolites of the model carcinogen 2-acetylaminofluorene (AAF) produced by human and rat hepatocytes were s...

The effects of dietary unsaturated and saturated fats on chemically induced colon carcinogenesis were examined in male Donryu rats. The rats were fed two types of semipurified diets consisting of 5% linoleic acid or 4.7% stearic acid plus 0.3% essential fatty acid as dietary fats. The rats were treated with azoxymethane (7.4 mg/kg body weight) s.c. once a week for 11 weeks and sacrificed 15 wee...

In considering the explanation of the recognized influence of the solvent upon the carcinogenic effectiveness of a dissolved carcinogen we have focussed our attention upon the physical factors which affect the availability of the carcinogen to the tissues in situ. An attempted formulation (see Discussion) of a possible mechanism of transfer from the solvent to the nearby affected tissue suggest...

1,25-Dihydroxyvitamin D(3) (1,25D(3)) is the biologically active form of vitamin D(3) that interacts with the nuclear vitamin D(3) receptor (VDR) to modulate gene expression in a tissue-specific fashion. 1,25D(3) is a potent regulator of cell proliferation, differentiation and apoptosis in a variety of cell types, including keratinocytes. In these studies, we assessed the sensitivity of mice ho...

Energy restriction (ER) to control weight is a potential strategy for breast cancer prevention. The protective effects of habitual continuous energy restriction (CER) and weight loss on breast tumour formation have been conclusively demonstrated in animal studies over the past 100 years, and more recently in women using data from observational studies and bariatric surgery. Intermittent energy ...