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Effect
of dietary vitamin A or N-acetylcysteine on ethylnitrosourea-induced rat gliomas
Ross DA, Kish P, Muraszko KM, Blaivas M, Strawderman M.
Brain Tumor Research Laboratory, University of Michigan Medical
Center, USA.
It is our hypothesis that low grade gliomas are the glial counterparts of other
precancerous lesions such as colon polyps and, therefore, suitable targets for
chemoprevention.
Steps in the molecular progression of gliomas have been described, indicating
that an accumulation of abnormalities is required for progression to a high
grade and interruption of this progression might be possible.
An animal model of chemical glial carcinogenesis was used to test this
hypothesis.
Pregnant rats were injected intravenously with ENU (ethylnitrosourea) on the
18th day of gestation to induce gliomas in the offspring, which were randomized
to receive control diet, diet supplemented with vitamin A palmitate, or diet
supplemented with N-acetylcysteine.
Animals exposed to ENU and receiving a control diet developed brain tumors and
had a shortened life expectancy compared with rats unexposed to ENU.
The animals treated with NAC showed no statistically significant delay in the
time to tumor and no change in the histologic grade of the tumors when compared
with animals receiving control diet, but the time to death from any cause of NAC
treated animals differed significantly from untreated animals.
Animals receiving high dose VA had statistically significantly prolonged time to
tumor, survived significantly longer than untreated animals, but had no
reduction in the total number of tumors or change in the histologic grade of
their tumors.
The theoretical basis of these results is likely due to the putative mechanism
of action of these agents.
These data indicate that glioma chemoprevention is possible and deserves further
exploration.
PMID: 9874183 [PubMed - indexed for MEDLINE]
Source: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9874183&dopt=Abstract
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