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In order to discover new cancer chemopreventive agents from natural or synthetic products, a structurally diverse class of chemopreventive agents was evaluated using in vitro biomarker of inhibition of 12-O-tetradecanoylphorbol 13-acetate (TPA)-induced ornithine decarboxylase (ODC) activity in
m-Chloroperoxybenzoic acid (CPBA) was tested for its ability to induce the ornithine decarboxylase (ODC) marker of skin tumor promotion. In contrast to benzoyl peroxide, dicumyl peroxide, and 2-butanol peroxide, 5 mg of CPBA applied twice at a 72-h interval induce ODC activity at least as much as 3
alpha-Difluoromethylornithine (DFMO), an irreversible inhibitor of ornithine decarboxylase, inhibited B16 melanoma-induced angiogenesis in chick embryo chorioallantoic membrane and subsequently the growth of the tumor on the chorioallantoic membrane. These inhibitions were reversed by exogenous
Garlic oil, onion oil and one of its constituents, dipropenyl sulfide, all increase, to diverse degrees, glutathione (GSH) peroxidase (GSH:H2O2 oxidoreductase, EC 1.11.1.9) activity in isolated epidermal cells incubated in the presence or absence of the potent tumor promoter
Application of a single large dose (3.6 micromol) or smaller weekly repeated doses (0.2 micromol) of 7,12-dimethylbenz[a]anthracene (DMBA) to the skin of CD-1 mice led to a 20 to 50-fold increase in epidermal ornithine decarboxylase (ODC) (EC 4.1.1.17) activity as well as tumor formation. Retinoic
More than one application of the potent tumor-promoting agent, 12-O-tetradecanoylphorbol-13-acetate (TPA), to mouse skin at intervals of more than 48 h led to a larger induction of ornithine decarboxylase (EC 4.1.1.17; ODC) than did a single application. In contrast, at intervals of less than 24 h,
The activity and gene expression of ornithine decarboxylase (ODC, an indicator of tumour promotion) were induced by the phorbol ester tumour promoter, 12-O-tetradecanoylphorbol-13-acetate (TPA), in mouse skin. In the present study, the effect of colchicine, a microtubule-disrupting agent, on ODC
12-O-Tetradecanoyl phorbol-13-acetate (TPA), a tumor promoter, stimulates DNA synthesis in mouse epidermal cells in vivo and in vitro. This response appears to be mediated through polyamine metabolism because ornithine decarboxylase (L-ornithine carboxy-lyase, EC 4.1.1.17)activity is markedly
Deguelin, a plant-derived rotenoid, mediates potent chemopreventive responses through transcriptional regulation of phorbol ester-induced ornithine decarboxylase (ODC) activity. To explore the mechanism of this effect, the activity of this compound was evaluated with a number of model systems. Using
We investigated the use of ornithine alpha-ketoglutarate in treatment of rats bearing Morris hepatoma 7777. Rats received diets containing either ornithine alpha-ketoglutarate, which has been used in other catabolic states (i.e. injury, sepsis), or an isonitrogenous, isocaloric diet containing
The nonprotein amino acid ornithine is the major source of polyamines in mammalian physiological systems. Increased urinary polyamine levels have been demonstrated in humans with varied types of cancers. The metabolism of DL-[1-14C]ornithine monohydrochloride in rats with either Walker 256 carcinoma
Consumption of argemone oil (AO) contaminated edible oil causes "Epidemic Dropsy". Previously, we have shown that AO and isolated sanguinarine possess genotoxicity and skin tumor initiating activity. Here, we evaluate tumor-promoting potential of AO/sanguinarine alkaloid and investigate the
BACKGROUND
Nonsmall cell lung carcinomas (NSCLCs) are associated with very dismal prognoses, and adjuvant chemotherapy, including irinotecan, taxanes, platin, and vinca alkaloid derivatives, offer patients only slight clinical benefits. Part of the chemoresistance of NSCLC results from the
Both alpha-difluoromethyl ornithine (DFMO) and methylglyoxal bis (guanylhydrazone) (MGBG) inhibit sequential enzymatic reactions in the pathway of polyamine biosynthesis. Since polyamines may be important factors in proliferation of cancer cells and DFMO combined with MGBG has shown synergistic
The tumor promoter 12-O-tetradecanoylphorbol-13-acetate and the antileukemic agent mezerein are diterpene esters of plant origin with certain structural similarities. Both compounds, when applied topically to mouse skin, were equipotent on a molar basis in inducing hyperplasia, inflammation, and