Journal ArticleDOI
Induction of mouse epidermal ornithine decarboxylase activity and skin tumors by 7, 12-dimethylbenz[a]anthracene: modulation by retinoic acid and 7,8-benzoflavone
Reads0
Chats0
TLDR
The results indicate that DMBA-induced ODC activity may be an important component of the mechanism of DMBA carcinogenesis, and the protective effect of retinoic acid on skin carcinogenesis is not universal; it inhibits skin tumor formation by some agents and not by others.Abstract:
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 acid (0.17-68 nmol), a potent inhibitor of both the induction of ODC activity and tumor formation by the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA), failed to inhibit both the induction of ODC activity and tumor formation by DMBA. In contrast, 7,8-benzoflavone (367 nmol), which did not inhibit the induction of ODC activity by TPA, effectively inhibited the induction of ODC activity as well as the formation of skin tumors caused by DMBA. These results indicate that (a) the mechanism of the induction of ODC activity and tumor formation by a complete carcinogen appears to be different from that of the tumor promoter TPA, (b) DMBA-induced ODC activity may be an important component of the mechanism of DMBA carcinogenesis, and (c) the protective effect of retinoic acid on skin carcinogenesis is not universal; it inhibits skin tumor formation by some agents and not by others.read more
Citations
More filters
Journal Article
Chemoprevention of Cancer
TL;DR: This Perspective deals with the areas in cancer control that this field addresses, the promise that it holds, and the problems that must be solved in order to realize its goals.
Book ChapterDOI
Cellular Biology and Biochemistry of the Retinoids
TL;DR: In this paper, the cellular biology and biochemistry of the retinoids are discussed and the effects of retinoid on cell differentiation in many different types of epithelia.
Journal ArticleDOI
Multistage carcinogenesis in mouse skin
TL;DR: The mouse skin model of multistage carcinogenesis has for many years provided a conceptual framework for studying carcinogenesis mechanisms and potential means for inhibiting specific stages of carcinogenesis, and a summary of known inhibitors of specific stages and their proposed mechanisms of action is reviewed.
Journal ArticleDOI
Growth inhibition of transformed cells correlates with their junctional communication with normal cells.
TL;DR: It is shown that the growth inhibition of various chemically and virally transformed cell types in culture is inhibited when they are in contact with normal cell types, and that the cell-to-cell membrane channels of gap junctions are the likely conduits of the signals for this growth control.
Journal ArticleDOI
Epidermal expression of the translation inhibitor programmed cell death 4 suppresses tumorigenesis.
TL;DR: The results extend to an in vivo model the observations that Pdcd4 inhibits both translation initiation and AP-1 activation while decreasing benign tumor development and malignant progression, and seem to validate translation initiation as a novel target for cancer prevention.