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Quinone-induced DNA single strand breaks in rat hepatocytes and human chronic myelogenous leukaemic K562 cells.
- Source :
-
Biochemical pharmacology [Biochem Pharmacol] 1992 Jul 22; Vol. 44 (2), pp. 215-21. - Publication Year :
- 1992
-
Abstract
- In rat hepatocytes exposed to the quinones menadione and 2,3-dimethoxy-1,4-naphthoquinone (2,3-diOMe-1,4-NQ) a decrease in NAD+ is observed. DNA damage and activation of poly(ADP-ribose)polymerase are often associated with a decrease in NAD+. Using rat hepatocytes and human myeloid leukaemic cells (K562), we examined the extent of DNA damage induced by these quinones at non-toxic concentrations, i.e. at concentrations at which the cells completely exclude the dye trypan blue. Both quinones caused significant DNA damage at very low concentrations (5-100 microM). With 2,3-diOME-1,4-NQ (15 microM) or menadione (15 microM) single strand breaks (SSB) were observed at very early time points (less than 5 min), reaching a maximum between 20 and 30 min. Most SSB were repaired within 45 min of the removal of the quinones. Whilst extensive repair was observed within 4 hr of the removal of 2,3-diOMe-1,4-NQ (15 microM), only partial repair was observed following exposure to menadione (15 microM). SSB induced by 2,3-diOMe-1,4-NQ (15 microM) were completely inhibited by the iron chelator 1,10-phenanthroline (25 microM), whereas in cells exposed to menadione (15 microM) they were only partially inhibited. Finally, although the membrane integrity of K562 cells was unaffected by exposure to high concentrations of both quinones (less than or equal to 400 microM), cytostasis was observed at much lower concentrations (50 microM). Our results demonstrate that at very low concentrations these quinones induce extensive DNA damage possibly caused by hydroxyl radicals. The DNA damage was accompanied by an early cytostasis but no loss of membrane integrity.
- Subjects :
- Animals
Cell Division drug effects
DNA Damage
Dose-Response Relationship, Drug
Humans
Liver metabolism
NAD metabolism
Naphthoquinones antagonists & inhibitors
Phenanthrolines pharmacology
Rats
Trypan Blue
Tumor Cells, Cultured metabolism
Vitamin K antagonists & inhibitors
DNA, Single-Stranded drug effects
Liver drug effects
Naphthoquinones pharmacology
Tumor Cells, Cultured drug effects
Vitamin K physiology
Subjects
Details
- Language :
- English
- ISSN :
- 0006-2952
- Volume :
- 44
- Issue :
- 2
- Database :
- MEDLINE
- Journal :
- Biochemical pharmacology
- Publication Type :
- Academic Journal
- Accession number :
- 1642637
- Full Text :
- https://doi.org/10.1016/0006-2952(92)90003-2