Document Detail


Modification of the cytotoxic activity of mitomycin C by oxygen and ascorbic acid in Chinese hamster ovary cells and a repair-deficient mutant.
MedLine Citation:
PMID:  3084075     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The cellular and molecular damage produced by mitomycin C (MMC) in Chinese hamster ovary cells, AA8-4, and a repair deficient mutant of this line, UV-20, was studied by utilizing a system in which oxygen levels could be altered and monitored in solution during acute drug exposures. The cytotoxic activity of MMC decreased from hypoxic conditions to 1% oxygen in solution, while from 1 to 20% there was little change. The relative level of DNA cross-linking in cells was examined under these conditions by alkaline elution and found to increase as cell survival decreased. Utilizing a cell-free assay which detects formation of alkylating species it was confirmed that, while alkylation was observed under aerobic conditions, overall levels increased in the absence of oxygen. The presence of ascorbic acid in the exposure medium (0.284 mM) increased the aerobic but not the hypoxic cytotoxicity of MMC. This resulted in a diminished differential toxicity for cells exposed under aerobic versus hypoxic conditions in the presence of ascorbic acid. When ascorbic acid was present, net alkylation increased under aerobic conditions but was unchanged under hypoxic conditions. One interpretation of these results is that at least two mechanisms of activation of MMC to toxic intermediates may be present in these cells.
Authors:
R S Marshall; A M Rauth
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Cancer research     Volume:  46     ISSN:  0008-5472     ISO Abbreviation:  Cancer Res.     Publication Date:  1986 Jun 
Date Detail:
Created Date:  1986-06-25     Completed Date:  1986-06-25     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  2984705R     Medline TA:  Cancer Res     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  2709-13     Citation Subset:  IM    
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MeSH Terms
Descriptor/Qualifier:
Alkylation
Animals
Ascorbic Acid / pharmacology*
Biotransformation
Cell Survival / drug effects
Cells, Cultured
Cricetinae
Cricetulus
DNA / metabolism
DNA Repair*
Female
Hydrogen Peroxide / metabolism
Mitomycin
Mitomycins / metabolism,  pharmacology*
Mutation
Oxygen / pharmacology*
Chemical
Reg. No./Substance:
0/Mitomycins; 50-07-7/Mitomycin; 50-81-7/Ascorbic Acid; 7722-84-1/Hydrogen Peroxide; 7782-44-7/Oxygen; 9007-49-2/DNA

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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