Reactivity of fecapentaene-12 toward thiols, DNA, and these constituents in human fibroblasts.
Micromolar concentrations of fecapentaene-12, a mutagen found in human feces, decrease survival measured as colony-forming efficiency and membrane integrity of cultured human fibroblasts. Fecapentaene-12 also decreases the content of cellular free low-molecular-weight thiols including glutathione. Fecapentaene-12 reacts directly with glutathione by causing both decreased levels of free thiol and some concomitant formation of oxidized glutathione, indicating that thiol depletion is a result of both alkylation and oxidative reactions. Exposure of cells to 2 or 5 microM fecapentaene-12 causes significant amounts of DNA-interstrand cross-links and DNA-single strand breaks, respectively, whereas exposure to a higher concentration of fecapentaene-12, i.e., 10 microM, also causes significant DNA-protein cross-links. Results from the reaction of fecapentaene-12 with isolated plasmid DNA parallel the cellular pattern of DNA damage; primarily interstrand cross-links and strand breaks occur also in plasmid DNA. Taken together, these studies show that fecapentaene-12 is a potent cytotoxic and genotoxic agent which can react with cellular thiols and cause several types of DNA damage.
Dypbukt
J M
JM
Department of Toxicology, Karolinska Institutet, Stockholm, Sweden.
Edman
C C
CC
Sundqvist
K
K
Kakefuda
T
T
Plummer
S M
SM
Harris
C C
CC
Grafström
R C
RC
D002478:Cells, Cultured; D003114:Colony-Forming Units Assay; D004249:DNA Damage; D004269:DNA, Bacterial / Q000187:drug effects / Q000648:ultrastructure; D003958:Diamide / Q000494:pharmacology; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D008854:Microscopy, Electron; D009153:Mutagens / Q000494:pharmacology*; D010957:Plasmids / Q000187:drug effects; D011090:Polyenes / Q000494:pharmacology*; D012867:Skin / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D013438:Sulfhydryl Compounds / Q000378:metabolism; D014307:Trioxsalen / Q000494:pharmacology
D004269:DNA, Bacterial; D009153:Mutagens; D011090:Polyenes; D013438:Sulfhydryl Compounds; D003958:Diamide; C037357:1-(1-glycero)dodeca-1,3,5,7,9-pentaene; D005978:Glutathione; D014307:Trioxsalen