7,12-Dimethylbenz-[a]anthracene (DMBA) is an environmental carcinogen which has a potent ovotoxic affect on rat and mouse ovaries, causing complete follicular depletion resulting in premature ovarian failure. Although the overall effects of DMBA on ovarian folliculogenesis are well known, little is known about the exact molecular mechanisms behind its ovotoxicity. In this study, we characterize...

7,12-Dimethylbenz(a)anthracene (DMBA):deoxyribonucleoside adducts, from enzymic hydrolyses of DNA from mouse embryo cells exposed in culture to [3H]DMBA, can be separated into two fractions on the basis of whether or not they bind to the phenyl boronic acid residues of Servacel DHB. This suggests that these two fractions of adducts are derived from anti and syn bay-region dihydrodiol-epoxides, ...

Polycyclic aromatic hydrocarbons (PAHs) are known immunotoxins and carcinogens. Our laboratory and others have demonstrated that metabolism of these compounds by CYP1B1 is required for carcinogenicity and immunotoxicity to occur. Previously, our laboratory reported significantly decreased bone marrow cellularity in mice following 7,12-dimethlybenz[a]anthracene (DMBA) administration. In addition...

Female Sprague-Dawley 5-day-old rats were given s.c. either 0.05 ml sesame oil, 1.25 mg progesterone, 0.1 mg estradici benzoate, or 1.25 mg testosterone propionate. At 55 days of age all rats were given 20 mg of 7,12-dimethylbenz(a)anthracene (DMBA) by stomach tube. All rats were killed at 190 days of age. Both the estradiol and the testosterone propionate treatments decreased the mammary adeno...

The effect of Eruca sativa seed extract (SE) on nuclear factor kappa B (NF-κB), cyclooxygenase-2 (COX-2) and B-cell lymphoma-2 (Bcl-2) gene expression levels was investigated in rat mammary gland carcinogenesis induced by 7,12 dimethylbenz(α)anthracene (DMBA). DMBA increased NF-κB, COX-2 and Bcl-2 gene expression levels and lipid peroxidation (LP), while, decreased glutathione-S-transferase (GS...

Secondary cultures of hamster embryo cells exposed to 0.5 nmol [G-3H]7,12-dimethylbenz(a)anthracene (DMBA) per ml medium metabolized more than 90% of the DMBA within 48 hr. Samples of medium were extracted with chloroform, methanol, and water. The chloroform phases contained about one-third of the DMBA metabolites; the major chloroform-extractable metabolite was 8,9-dihydro-8,9-dihydroxy-7,12-d...

Sphingosine (SPH) was studied as an inhibitor of skin tumor promotion in skin cancer initiated by 7,12-dimethylbenz[a]-anthracene (DMBA) and promoted by 12-O-tetradecanoylphorbol-13-acetate (TPA). Two tumorigenesis studies were conducted using female Sencar mice treated with 10 nmol DMBA in 0.2 ml acetone at 8 weeks of age and promoted beginning 1 week later with 3.2 nmol TPA applied twice per ...

The identification of a new protein, p73, with structural and functional similarities to p53 protein suggests that a family of p53-like proteins is likely to exist. This study investigated the status of p73 protein in the early stages of 7,12-dimethyl benz[a]anthracene (DMBA)-induced carcinogenesis. Outbred young (6-week-old) male Syrian golden hamsters (Mesocricatus auratus; 40 animals) were r...

Iron body-stores and iron dietary intake have been sporadically reported to increase the risk of cancer in humans. To investigate the effect of iron on the development of mammary tumors, female Sprague-Dawley rats were given dimethylbenz[a]anthracene (DMBA) (5 mg/kg, i.g., 1x) at 55 days of age. Eight days later, rats received iron(II) sulfate s.c. (50 micromol/kg, 2x/week) for 53 weeks. Mammar...