Faculty Collaboration Database

Evidence for the metabolism of tumor promoter organic hydroperoxides into free radicals by human carcinoma skin keratinocytes: an ESR-spin trapping study. Carcinogenesis 1989 Aug;10(8):1499-503

Date

08/01/1989

Pubmed ID

2473853

DOI

10.1093/carcin/10.8.1499

Scopus ID

2-s2.0-0024336057 (requires institutional sign-in at Scopus site)   57 Citations

Abstract

Humans are exposed to various peroxy and hydroperoxy compounds which are in use in the cosmetic, pharmaceutical and polymer industries and which are also generated as a result of the peroxidative metabolic conversion of certain lipids. This study was designed to determine whether the organic hydroperoxides, tert-butyl hydroperoxide, cumene hydroperoxide and tert-butyl peroxybenzoate are metabolized by human carcinoma skin keratinocytes to free radicals. Incubation of keratinocytes prepared from cutaneous squamous cell carcinoma in phosphate-buffered saline (pH 7.4) containing desferrioxamine with tert-butyl hydroperoxide, cumene hydroperoxide and tert-butyl peroxybenzoate in the presence of spin trap (3,5-dibromonitrosobenzene sulfonic acid) resulted in the generation of corresponding methyl radical adducts. Prior heating of the cells to 100 degrees C abolished the generation of radical adducts. The addition of ethanol to the reaction mixture also inhibited formation of radical adducts. These data provide the first direct evidence that human carcinoma skin cells can generate free radicals from organic hydroperoxides. Since free radicals are suggested to be involved in the cascade of events occurring during tumor promotion this metabolic capacity may be an important determinant of human cancer risk for hydroperoxides.

Author List

Athar M, Mukhtar H, Bickers DR, Khan IU, Kalyanaraman B

Author

Balaraman Kalyanaraman PhD Professor in the Biophysics department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Benzene Derivatives
Benzenesulfonates
Benzoates
Carcinoma, Squamous Cell
Cell Line
Electron Spin Resonance Spectroscopy
Epidermis
Free Radicals
Humans
Keratins
Kinetics
Nitroso Compounds
Peroxides
Skin Neoplasms
Spin Labels
tert-Butylhydroperoxide