All-trans beta-carotene enhances mitogenic responses and ornithine decarboxylase activity of BALB/c 3T3 fibroblast cells induced by tumor promoter and fetal bovine serum but suppresses mutagen-dependent umu C gene expression in Salmonella typhimurium (TA 1535/pSK 1002).
Although previous epidemiological studies have indicated that beta-carotene is an important agent for the chemical prevention against carcinogenesis, a recent prospective study has strikingly suggested that supplementation with beta-carotene significantly increased the incidence of some types of cancer (The alpha-Tocopherol and beta-Carotene Cancer Prevention Study Group, New Engl. J. Med., 330 (1994) 1031-1035). To analyze the discrepancy of this problem, the authors analyze the effects of beta-carotene on biochemical and biological events associated with carcinogenesis by in vitro experiments. (1) All-trans beta-carotene enhanced the proliferation and DNA synthesis of BALB/c 3T3 cells induced by a tumor promoter, 12-O-tetradecanoyl-phorbol-13-acetate (TPA) and fetal bovine serum, although beta-carotene itself did not show mitogenic activity. (2) All-trans beta-carotene caused a remarkable stimulation for the early induction of ornithine decarboxylase (ODC) activity after the stimulation of TPA and fetal bovine serum. (3) All-trans beta-carotene exhibited significant antimutagenic activity which suppresses umu C gene expression in Salmonella typhimurium (TA 1535/pSK 1002) induced by a typical mutagen, 2-aminoanthracene (2-AA). These experimental results suggest that all-trans beta-carotene might cause beneficial and harmful effects on different phases of carcinogenesis.
Okai
Y
Y
Division of Food and Nutrition, Osaka Kun-ei Women's College, Japan.
Higashi-Okai
K
K
Yano
Y
Y
Otani
S
S
D016475:3T3 Cells / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D000818:Animals; D000873:Anthracenes / Q000633:toxicity; D016587:Antimutagenic Agents / Q000494:pharmacology* / Q000633:toxicity; D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000235:genetics; D002273:Carcinogens / Q000633:toxicity*; D002338:Carotenoids / Q000494:pharmacology* / Q000633:toxicity; D002417:Cattle; D002455:Cell Division / Q000187:drug effects; D004247:DNA / Q000096:biosynthesis / Q000187:drug effects; D004259:DNA-Directed DNA Polymerase; D004347:Drug Interactions; D004790:Enzyme Induction / Q000187:drug effects; D029968:Escherichia coli Proteins; D005312:Fetal Blood; D015870:Gene Expression / Q000187:drug effects; D051379:Mice; D008807:Mice, Inbred BALB C; D009153:Mutagens / Q000633:toxicity; D009955:Ornithine Decarboxylase / Q000096:biosynthesis / Q000187:drug effects / Q000378:metabolism*; D012486:Salmonella typhimurium / Q000187:drug effects* / Q000235:genetics* / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000633:toxicity*; D019207:beta Carotene
D000873:Anthracenes; D016587:Antimutagenic Agents; D001426:Bacterial Proteins; D002273:Carcinogens; D029968:Escherichia coli Proteins; D009153:Mutagens; D019207:beta Carotene; D002338:Carotenoids; C006593:2-anthramine; D004247:DNA; C078202:UmuC protein, E coli; D004259:DNA-Directed DNA Polymerase; D009955:Ornithine Decarboxylase; D013755:Tetradecanoylphorbol Acetate