Mutation of potassium permanganate- and hydrogen peroxide-treated plasmid pZ189 replicating in CV-1 monkey kidney cells.
We examined the effect of the oxidation of plasmid pZ189 by KMnO4, which does not produce free radicals, and H2O2/Fe(2+)-diethylenetriaminepentaacetic acid (DTPA), which does, on the mutation frequency of pZ189 transfected into monkey kidney CV-1 cells. Treatment with 1.5 mM KMnO4 increased the content of certain modified bases, principally Thy and Cyt modified at C-5 and C-6, by up to 300-fold, as measured by GC/MS; however, the mutation frequency increased only 5-fold above background. 1.0 mM H2O2/0.1 mM Fe(2+)-DTPA treatment, which increased the mutation frequency 10-fold above background, increased the content of certain modified bases by up to 4-fold. Sequence analysis revealed both deletions and point mutations, with a predominance of C-G substitutions, among H2O2/Fe(2+)-DTPA-associated mutations. These data suggest that KMnO4-modified DNA is only weakly mutagenic in DNA replicating in mammalian nuclei, despite substantial production of Thy glycol and other base modifications, whereas H2O2/Fe(2+)-DTPA-modified DNA is more mutagenic. H2O2/Fe(2+)-DTPA generated mutations occur predominantly at C-G base pairs.
Department of Medical Oncology and Therapeutics Research, City of Hope National Medical Center, Duarte, CA 91010.
S A
SA
Akman
G P
GP
Forrest
J H
JH
Doroshow
M
M
Dizdaroglu
D000818:Animals; D001483:Base Sequence; D002522:Chlorocebus aethiops / Q000235:genetics; D004249:DNA Damage; D006861:Hydrogen Peroxide / Q000633:toxicity*; D066298:In Vitro Techniques; D008969:Molecular Sequence Data; D009154:Mutation; D010084:Oxidation-Reduction; D010957:Plasmids / Q000187:drug effects; D011196:Potassium Permanganate / Q000633:toxicity*; D012689:Sequence Homology, Nucleic Acid; D014162:Transfection
D011196:Potassium Permanganate; D006861:Hydrogen Peroxide