These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Effects of indole-3-carbinol on lung tumorigenesis and DNA methylation induced by 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and on the metabolism and disposition of NNK in A/J mice.
    Author: Morse MA, LaGreca SD, Amin SG, Chung FL.
    Journal: Cancer Res; 1990 May 01; 50(9):2613-7. PubMed ID: 2328487.
    Abstract:
    The effects of indole-3-carbinol (I3C) on lung neoplasia induced by the tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) were assessed in an A/J mouse pulmonary adenoma bioassay. Mice were administered corn oil or I3C (25 or 125 mumol/mouse/day) by gavage for 4 consecutive days. Two h after the final pretreatment, mice were administered a single dose of NNK (10 mumol/mouse) i.p. Pulmonary adenomas were quantitated 16 wk after NNK dosing. Mice pretreated with corn oil developed 10.7 tumors/mouse; I3C pretreatment at either dose level inhibited tumor multiplicity by approximately 40%. The effects of I3C on NNK-induced DNA methylation in the lungs and livers of A/J mice were assessed using the same dosing regimen as in the bioassay. Both dose levels of I3C inhibited pulmonary O6-methylguanine formation by at least 50%, but enhanced hepatic DNA methylation at 2 or at 6 h after NNK administration. The effects of I3C pretreatment on NNK metabolism were also investigated. Hepatic microsomes of I3C-pretreated mice showed increased formation of alpha-hydroxylation products, while no significant effect of I3C pretreatment was observed in pulmonary microsomes. The effects of I3C on [5-3H]NNK disposition were also evaluated. I3C pretreatment produced lower levels of total radioactivity in the lung when compared with controls. Additionally, lower proportions of NNK and its carcinogenic metabolite 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol were found in the lungs of I3C-pretreated mice. These results demonstrate that I3C inhibits NNK-induced lung neoplasia in A/J mice and suggest that the basis of this inhibition is the decrease in O6-methylguanine formation in A/J lung caused by I3C pretreatment. This decrease in lung DNA methylation appears to be due to the decreased bioavailability of NNK and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol in the lungs of I3C-treated mice which, in turn, may be a result of increased metabolic alpha-hydroxylation of NNK by the liver.
    [Abstract] [Full Text] [Related] [New Search]