Induced skin tumor

Mathews-Roth M. M. and Krinsky N. I. (1984). Effect of dietary fat level on UV-B induced skin tumors, and anti-tumor action of beta-carotene. Photochem Photobiol 40(5) 671-673. 

Klecak, G., Urbach, E. and Urwyler, H. (1997) Fluoroquinolone antibacterials enhance UVA-induced skin tumors. Journal of Photochemistry and Photobiology B, Biology, 37, 174-181. 

Ornithine decarboxylase activity. Fixed oil (4.5%), Clupeidae brevortia tyrannus (4%), and Zea mays (1.5%) fixed oil (7.5%), Clupeidae brevortia tyrannus (1%), and Zea mays (1.5%) fixed oil (8.5%) and Zea mays (1.5%), administered orally to mice for 1 year, were active vs benzoyl peroxide-induced ornithine decarboxylase activity Oil, administered to 30 ultraviolet (UV)-irradiated Senear and SKH-1 mice at doses of 1/14% (A diet), 7.9/7.1% (B diet), and 15/0% (C diet) corn oil/coco-nut oil for 6 weeks, produced no increase in enzyme activity. The level of ornithine decarboxylase activity in the UV-irradiated mice fed diet A was significantly higher than in mice fed the B or C diet. In the SKH-1 mice, ornithine decarboxylase activity was increased by 3 weeks and was significantly higher in mice fed diet C than in mice fed diet A. There was no significant effect of dietary fat on UV-induced skin tumor incidence ". 

Skin 1 Inhibition of 7,12-dimethylbenz[a Janthracene (DMBA 2)/TPA induced skin tumors (Topical application) [8,3739-42]... 

Skin 11 Inhibition of DMBA/TPA induced skin tumors (Oral application) [43]... 

Assay for Iinhibition of DMBA/TPA Induced Skin Tumors in Mice... 

Huang et al. [70] have evaluated the effects of chlorogenic acids on tumor promotion in an animal study using CD-I mice. Chlorogenic, caffeic and ferulic acids inhibit the induction of ornithine decarboxylase by 12-O-tetradecanoylphorbol-13-acetate (TPA). TPA-mediated DNA synthesis has been weakly inhibited, but TPA-induced skin tumor promotion has been markedly inhibited by these compounds. 

Wang ZY, Khan WA, Bickers DR, Mukhtar H. 1989. Protection against polycyclic aromatic hydrocarbon-induced skin tumor initiation in mice by green tea polyphenols. Carcinogenesis 10 411-415. 

Application of 2-nitrophenol or 4-nitrophenol (dissolved in dioxane) to the shaved backs of mice in doses of 47 mg nitrophenol/kg/day for 12 weeks did not induce skin tumors or lesions that could be considered precancerous in nature (Boutwell and Bosch 1959). These results should be interpreted with caution, since no other site was examined and the duration of the study may have been too short for evaluating carcinogenic potential. 

Skin-2 Inhibition of DMBA/teleocidin B induced skin tumors... 

Spalding JW, French JE, Tice RR, Furedi-Machacek M, Haseman JK, Tennant RW (1999) Development of a transgenic mouse model for carcinogenesis bioassays evaluation of chemically induced skin tumors in Tg.AC mice. Toxicological Science 49 241-254... 

Dermal exposure to benzene did not induce skin tumors in mice (Bull et al. 1986). No papillomas developed in mice that were given a 2-week, 800 mg/kg/day topical application of benzene as the initiator and a 1 pg topical application of 12-o-tetradecanoylphorbol-13-acetate 3 times a week for 20 weeks and observed for 52 weeks (Bull et al. 1986). The authors concluded that it is difficult to estimate benzene-induced tumor incidence after dermal exposure, and that mouse skin may not be the optimal study system. This is because of the high rate of false-negative responses to chemicals, like benzene, with recognized carcinogenic activity. 

Bai Y, Edamatsu H, Maeda S, Saito H, Suzuki N, Satoh T, Kataoka T. Crucial role of phospholipase cepsilon in chemical carcinogen-induced skin tumor development. Cancer Res. 2004 64 8808-8810. 

Human papillomavirus has been implicated as a co-factor in the pathogenesis of arsenic-induced skin tumors (23). 

Benzo[a]pyrene-induced skin tumors were decreased in diet restricted ABC, C57, and Swiss strains of mice. Interestingly, it was demonstrated that the decrease in tumor incidence is independent of any particular source of calories. Contrary to the popular belief of low-fat or low-carb diets, it was demonstrated that decrease in cancers following DR depends mainly upon reduction in the total number of calories rather than decrease in calories coming from either only fat or carbohydrates. Since the first reports in the 1940s to 1950s, the anticarcinogenic effect of DR on chemical-induced tumors has been extensively studied in various tissues and after exposure to a variety of chemicals. 

UV is known to induce nonmelanoma skin cancer. Ethanol and aloe emodin alone do not induce skin tumors in the absence of UV. When an ethanol solution of aloe emodin was painted onto the skin of mice in conjunction with UVB exposure, the mice developed melanin-containing skin tumors. The mechanism for the observed carcinogenesis induction by the mixture is unknown, 91... 

The PAHs tend to be irritating to the skin. In addition, benzo(a)pyrene has been shown to cause immunological/lymphoreticular effects evidence as contact hypersensitivity or suppression of this response to other sensitizers. The PAHs classified as B2 carcinogens induce skin tumors following intermediate dermal application to animals (ATSDR 1995f). 

Study with hr/hr Oslo mice, decreased the latency period for the appearance of DMBA-induced skin tumors. The report of this study did not mention if non-neoplastic skin lesions were produced by exposure with 4% formaldehyde solutions. 

Complete Carcinogenesis Studies. Studies in laboratory animals have demonstrated the ability of benz[a]anthracene, benzo[b]fluoranthene, benzo[j]fluoranthene, benzo[a]pyrene, chrysene, dibenz[a,h,]anthracene, and indeno[1,2,3-c,d]pyrene to induce skin tumors (i.e., they are complete carcinogens) following intermediate dermal exposure. Anthracene, fluoranthene, fluorene, phenanthrene, and pyrene do not act as complete carcinogens. The data supporting these conclusions are discussed below by chemical. Only those studies considered adequate and reliable with respect to study design and adequacy of reporting are presented in Table 2-3. 

Chronic dermal application of up to 1 % fluoranthene to the backs of mice did not induce skin tumors following a lifetime of application (Hoffmann et al. 1972 Horton and Christian 1974 Wynder and Hoffmann 1959a). 

Inhibition of A -nitrobis-(2-hydroxypropyl)amine (BHP) induced pancreatic tumors Inhibition of DMBA/TPA induced skin tumors Inhibition of DMBA/teleocidin B induced skin tumors Inhibition of DMBA/fumonsin-Bl induced skin tumors Inhibition ofNOR-l/TPA induced skin tumors Inhibition of DMBA/okadaic acid induced skin tumors Inhibition of DMBA/mineral oil induced skin tumors... 

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