chrysarobin/hyperplasia

The present study was designed to further investigate the role of reactive oxygen species in the mechanism of action of anthrone tumor promoters. To accomplish this, the effects of several antioxidants on the induction of epidermal ornithine decarboxylase (ODC) activity, epidermal hyperplasia, skin

The skin tumor-promoting ability of 1,8-dihydroxy-3-methyl-9-anthrone (chrysarobin) was compared with that of 12-O-tetradecanoylphorbol-13-acetate (TPA) and 1,8-dihydroxy-9-anthrone (anthralin) in SENCAR mice. Although dose-response comparisons indicated that chrysarobin was several orders of

Histologic changes induced in SENCAR skin following a single treatment with chrysarobin (1,8-dihydroxy-3-methyl-9-anthrone) exhibited differences in time course from that observed with 12-O-tetradecanoylphorbol-13-acetate (TPA). Although not significantly different, maximum elevations in epidermal

Skin carcinogenesis can be operationally and mechanistically divided into at least three major stages - initiation, promotion and progression. Variations among stocks and strains of mice to susceptibility to multistage skin carcinogenesis appear to be more related to alterations in tumor promotion

The study presented here was designed to further investigate the role of transforming growth factor-alpha (TGF alpha) in skin tumor promotion by examining the ability of 12-O-tetradecanoylphorbol-13-acetate (TPA) and several non-phorbol ester promoters to alter TGF alpha mRNA and protein levels in

The effects of multiple applications of 12-O-tetradecanoyl-phorbol-13-acetate (TPA, 6.8 nmol), teleocidin (6.8 nmol), 1,8-dihydroxy-3-methyl-9-anthrone (chrysarobin, 220 nmol), mezerein (6.8 nmol), 4-O-Methyl-TPA (4-O-Me-TPA, 150 micrograms) and benzoyl peroxide (BzP, 20 mg) on the skin of DBA/2 and

The present study has compared different mouse stocks and strains with known sensitivity to phorbol ester skin tumor promotion for their sensitivities to skin tumor promotion by a prototypic organic peroxide (benzoyl peroxide, BzPo) and anthrone (chrysarobin, Chr) tumor promoter. Following

The inhibition of gap-junctional intercellular communication (GJIC) between initiated and surrounding normal cells by tumor promoters is believed to be important in the promotion stage of carcinogenesis. Therefore, we examined the effect of skin-tumor promoters on the expression of the

The effects of promoter treatments prior to initiation on subsequent promotion by mezerein were examined in SENCAR mice. Groups of mice received two applications of various complete as well as first and second stage promoters given at various time intervals prior to initiation ranging from 3 days to

Previous work from our laboratory demonstrated that 12-O-tetradecanoylphorbol-13-acetate (TPA) or a synthetic diacylglycerol induced significantly higher epidermal ornithine decarboxylase (ODC) activity in C57BL/6 than in DBA/2 mice. To understand further the genetic basis for this strain

Insulin-like growth factor-1 (IGF-1) and its receptor are believed to play an important role in mitogenesis and neoplastic transformation. The purpose of this study was to further examine the role of IGF-1 during tumor promotion in mouse skin. HK1.IGF1 transgenic mice, which overexpress IGF-1 in

Glucocorticoid hormones are very potent inhibitors of keratinocyte proliferation. Their function is mediated by the glucocorticoid receptor (GR) which is highly expressed in mouse epidermis. In the study reported here we compared the effect of 12-O-tetradecanoyl-phorbol-13-acetate (TPA) and

The present study was designed to further investigate the role of the epidermal growth factor receptor (EGFr) in mouse skin tumor promotion by evaluating the status of the EGFr in tumor promoter-treated mouse epidermis and in mouse skin tumors. Female SENCAR mice received three topical treatments of

The present study investigated a possible role for Ca2+ in skin tumor promotion by anthrones. This was accomplished by testing the effects of two Ca2+ antagonists, verapamil and 3,4,5-trimethoxybenzoic acid 8-(diethylamino) octyl ester (TMB-8), on tumor promotion and promoter-related effects induced