Carcinogen induced mutation in somatic cells leads to genetic instability, which is considered as an important facet of carcinogenesis. Agents that inhibit DNA adduct formation, stimulate DNA repair mechanisms, and possess antioxidant functions are considered as antigenotoxic agents. Genistein, the major isoflavone of soy products, protects animals against experimentally induced mammary and pro...

7,12-Dimethylbenz(a)anthracene (DMBA) rapidly suppresses hematopoietic progenitors, measured as colony forming units (CFU), in mouse bone marrow (BM) leading to mature cell losses as replenishment fails. These losses are mediated by Cyp1b1, independent of the AhR, despite induction of Cyp1b1. BM mesenchymal progenitor cells (MPC) may mediate these responses since basal Cyp1b1 is minimally induc...

NRH:Quinone oxidoreductase 2 (NQO2) is an enzyme that catalyzes the reductive metabolism of quinones. C57BL/6 NQO2-/- mice lacking NQO2 gene expression were generated in our laboratory. The dorsal skin of NQO2-deficient mice was exposed to 7,12-dimethylbenz(a)anthracene (DMBA) or benzo(a)pyrene alone (complete carcinogen) or with 12-O-tetradecanoylphorbol-13-acetate (TPA) (initiation/promotion ...

In the experimental rat leukemia system, induced by repeated 7,12-dimethylbenz(a)anthracene (DMBA) pulses, the sensitivity of the spleen colony-forming hematopoietic stem cells (CFU-s) to the cytocidal action of a challenging DMBA injection (35 mg/kg body weight) varied with the number of pulses already applied and the organ source of CFU-s (femoral bone marrow or spleen). Assessment of the fra...

As reações do ciclopaladado catiônico [Pd(N,C-dmba)(MeCN) 2 ](NO 3 ) (1) (dmba = N,Ndimetilbenzilamina), como os pré-ligantes 3,5-dimetilpirazol (Hdmpz); 2-quinolinatiol (qnSH) e 1,1’-bis(difenilfosfina)ferroceno (dppf) levaram à formação dos compostos, respectivamente, [Pd(N,C-dmba)(Hdmpz)(ONO 2 )]0.5CH 2 Cl 2 (2), [Pd(N,C-dmba)(qnSH)(ONO 2 )] 0.5CH 2 Cl 2 (3) e [Pd(N,C-dmba)(dppf)](NO 3 ) (4)...

The R-ras gene encodes a small GTPase that is a member of the Ras family. Despite close sequence similarities, R-Ras is functionally distinct from the prototypic Ras proteins; no transformative activity and no activating mutations of R-Ras in human malignancies have been reported for it. R-Ras activity appears inhibitory towards tumour proliferation and invasion, and to promote cellular quiesce...

The effects of hyperbaric oxygen (HBO) on mouse skin two-stage chemical carcinogenesis were examined. Six-week-old inbred CD-1 female mice were divided into the following five groups: group 1, normoxia and application of 25 nmol 7,12-dimethylbenz[a]anthracene (DMBA) and 8.5 nmol 12-O-tetradecanoylphorbol-13-acetate (TPA) (n=19); group 2, HBO and DMBA/TPA (n=21); group 3, HBO and DMBA/acetone (n...

Our aim was to explore anti-cell proliferative and anti-angiogenic potential of andrographolide by analyzing the expression pattern of cell proliferative (PCNA, Cyclin D1) and angiogenic (VEGF) markers during 7, 12-dimethylbenz(a)anthracene (DMBA) induced hamster buccal pouch carcinogenesis. DMBA painting three times a week for 14 weeks in the buccal pouch of golden Syrian hamsters resulted in ...

The present study evaluated the chemopreventive potential of (6)-paradol, a pungent phenolic constituent of ginger, on 7,12-dimethylbenz(a)anthracene (DMBA)-induced hamster buccal pouch carcinogenesis. The mechanistic pathway for the chemopreventive potential of (6)-paradol was evaluated by measuring the status of tumor incidence, volume and burden as well as by analyzing the status of phase II...

In the hormonally responsive 7,12-dimethylbenz(a)anthracene (DMBA)- or N-nitrosomethylurea (NMU)-induced mammary carcinomas, regulatory mechanisms have been altered such that these tumors retain their hormonal dependence for growth but possess only a limited ability to synthesize the mammary gland-specific milk proteins. Quantitation of casein mRNA levels revealed that very low levels of casein...