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7,12-Dimethylbenz[a]anthracene
About: 7,12-Dimethylbenz[a]anthracene is a research topic. Over the lifetime, 1717 publications have been published within this topic receiving 40892 citations.
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TL;DR: The protective effect provided by HCG against DMBA-induced mammary tumorigenesis may be attributed to its able to inhibit binding of the carcinogen to mammary cell DNA and to its ability to increase the level of excision repair in the cells.
17 citations
TL;DR: Cultured Syrian hamster embryo cells readily convert both the carcinogenic polycyclic aromatic hydrocarbon, 7,12-dimethylbenz[a]anthracene (DMBA), and its weakly carcinogenic analogue, 5-fluoro-7, 12-dimethylamine (5F-DMBA) to water soluble metabolites, but the latter compound binds to DNA more effectively.
17 citations
TL;DR: The European hamster occupies a special position since all of the DMBA-TPA sensitive two-stage target organs known from the mouse, rabbit, Syrian golden hamster and rat are combined in this animal.
Abstract: Initiation with the carcinogen 7,12-dimethylbenz[a]anthracene followed by promotion with the hyperplasiogenic phorbol ester 12-O-tetradecanoylphorbol-13-acetate carried out on the dorsal skin of European hamsters (Cricetus cricetus L.) led to the formation of a broad spectrum of skin tumors in terms of a two-stage principle. Tumor formation involved the epidermis and its appendages, the connective tissue, and the vascular and pigmentary system. With regard to the sensitivity to initiation with DMBA alone and initiation with DMBA and promotion with TPA the European hamster occupies a special position since all of the DMBA-TPA sensitive two-stage target organs known from the mouse, rabbit, Syrian golden hamster and rat are combined in this animal.
17 citations
TL;DR: The combined results indicate that incomplete spindles caused by BP resulted in aneuploidsy, and the absence of spindle formation caused by DMBA resulted in polyploidy, which suggests that this cell line might be a good tool for studying chemicals that induce numerical chromosome aberrations.
Abstract: We previously reported that benzo[a]pyrene (BP) and 7, 12-dimethylbenz[a]anthracene (DMBA) induce aneuploidy and polyploidy, respectively, in the Chinese hamster cell line V79-MZ in the absence of S9 mix. In the present study we investigated the effect of BP and DMBA on the mitotic spindle. BP caused incomplete spindle formation and DMBA inhibited spindle formation completely. The combined results indicate that incomplete spindles caused by BP resulted in aneuploidy, and the absence of spindle formation caused by DMBA resulted in polyploidy. The induced polyploidy was stable for several serial passages in fresh medium. BP and DMBA induced different chromosome number distributions. After BP treatment, the normal distribution of chromosome number was restored in 4 days. After DMBA treatment, on the other hand, a tetraploid peak was maintained for 2 months following an initial transient broad distribution of chromosome number after 1 day. The results suggest that different mechanisms were involved in the induction of numerical aberrations by BP and DMBA. Furthermore the induction of numerical aberrations by BP and DMBA was reproducible over 5 months of passages. In four clones tested, the frequency of cells with the modal chromosome number in control cultures gradually decreased from 82% on the average just after cloning to 62% 5 months later. BP and DMBA induced characteristic ploidy changes following succeeding cell passages for up to 5 months, indicating that the ability to respond to BP and DMBA was stable for that period of time. Because these findings were specific to V79-MZ cells, this cell line might be a good tool for studying chemicals that induce numerical chromosome aberrations.
17 citations
TL;DR: The present data strongly suggest that anticancer potentiality of (+)-catechin-rich AQCE may be attributable to its ability to positively modulate tumor markers as well as the antioxidant system that could decompose the peroxides and, thereby, offer a protection against lipid peroxidation.
Abstract: Objective. The chemopreventive potential of (+)-catechin-rich extract of Acacia catechu (L.f.) Willd. heartwood (AQCE) was evaluated against human breast adenocarcinoma cell line (MCF-7) and 7,12-dimethylbenz[a]anthracene (DMBA)–induced mammary carcinoma in Balb/c mice. Methods. Cell cytotoxicity was investigated using different colorimetric assays. Apoptosis was observed using diphenylamine assay and fluorescent microscopy. AQCE was further evaluated for antitumor activity against DMBA-induced mammary carcinoma. The levels of tumor markers and oxidative stress were measured. Furthermore, level of transcription factors was measured by enzyme-linked immunosorbent assay. Results. The results showed that administration of AQCE showed a dose-dependent growth inhibition response and DNA fragmentation in MCF-7 cells. Tumor multiplicity was significantly decreased to 42.91% with AQCE when compared with DMBA-treated animals. The levels of tumor markers such as total sialic acid and lipid-associated sialic acid we...
17 citations