Detail of "57-97-6"

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Lack of an effect of dietary retinoids in chemical carcinogenesis of the mouse mammary gland: inverse relationship between mammary tumor cell anaplasia and retinoid efficacy

Lack of an effect of dietary retinoids in chemical carcinogenesis of the mouse mammary gland: inverse relationship between mammary tumor cell anaplasia and retinoid efficacy. Welsch, Clifford W.; DeHoog, Jane V.; Moon, Richard C. (Dep. Anat., Michigan State Univ., East Lansing, MI 48824, USA). Carcinogenesis (London), 5(10), 1301-4 (English) 1984. CODEN: CRNGDP. ISSN: 0143-3334. DOCUMENT TYPE: Journal CA Section: 18 (Animal Nutrition) Section cross-reference(s): 14 Feeding of retinyl acetate [127-47-9] (0.2 mM) or N-(4-hydroxyphenyl) retinamide (4-HPR) [65646-68-6] (1.0 mM) for 27 wk to female BD2F1 mice previously treated with a series of gastric intubations of 7,12-dimethylbenzanthracene (DMBA) [57-97-6], did not significantly affect the incidence of mammary tumors. In the retinyl acetate study, 75 retinyl acetate-fed mice developed 31 mammary adenocarcinomas and 19 mammary adenoacanthomas (42 total mammary tumors). In the 4-HPR study, 74 4-HPR fed mice developed 45 mammary adenocarcinomas and 41 mammary adenoacanthomas (86 total mammary tumors) whereas 74 control mice developed 29 mammary adenocarcinomas and 44 mammary adenoacanthomas (73 total mammary tumors). Retinoid treatments did not significantly affect body wt. gains or mortality rates. These results provide evidence that carcinogen induced mouse mammary gland tumorigenesis in vivo is not influenced by hyperalimentation of dietary retinoids.

Differentiation of cultured epidermal keratinocytes related to sterol metabolism and its retardation by chemical carcinogens

Differentiation of cultured epidermal keratinocytes related to sterol metabolism and its retardation by chemical carcinogens. Okamoto, Tetsuji; Moroyama, Takamasa; Morita, Tomoo; Yoshiga, Koji; Takada, Kazuaki; Okuda, Kyuichiro (Sch. Dent., Hiroshima Univ., Hiroshima 734, Japan). Biochim. Biophys. Acta, 805(2), 143-51 (English) 1984. CODEN: BBACAQ. ISSN: 0006-3002. DOCUMENT TYPE: Journal CA Section: 4 (Toxicology) The amt. of 5b-cholest-7-en-3b-ol (I) [16826-36-1] of mouse dorsal skin was increased after parturition until 10 days of age, reaching a max. I/5-cholesten-3b (II) [57-88-5] ratio of 0.43. [2-14C]acetate was incorporated almost exclusively into II in the basal cell culture of epidermal keratinocytes. However, when the concn. of Ca was changed from 0.07 to 1.9 mM to induce terminal differentiation of keratinocytes, a definite amt. of radioactive acetate was incorporated into I. The extent of the incorporation was increased at least until 72 h after changing medium, and the ratio of radioactive I/radioactive II was constantly increased in this period, indicating that the accumulation of I in the cell is concomitant with the differentiation of the cell. Pretreatment with chem. carcinogens such as 7,12-dimethylbenz[a]anthracene [57-97-6] and 20-methylcholanthrene [56-49-5] inhibited the incorporation of radioactive acetate into I in the high-Ca medium at least for the initial 24-h. After that, the incorporation was gradually restored to the normal level. Pretreatment with a tumor promoter, such as 12-O-tetradecanoylphorbol 13-acetate, however, did not inhibit the incorporation. Thus, sterol metab. is suggested to be a useful indicator for differentiation of epidermal keratinocytes.