Detection of styrene oxide-DNA adducts by 32P-postlabeling.
Liu-F; Rappaport-SM; Rasmussen-J; Bodell-WJ
Carcinogenesis 1988 Aug; 9(8):1401-1404
The formation of DNA adducts by styrene-7,8-oxide (96093) (styrene- oxide) was studied in-vitro. One to 30 microliters (microl) of styrene-oxide were reacted with 0.5 milligram calf thymus DNA, 2'- deoxyguanosine-3'-monophosphate (dGp), 2'-deoxyadenosine-3'- monophosphate (dAp), 2'-deoxycytidine-3'-monophosphate (dCp), or 2'- deoxythymidine-3'-monophosphate (dTp) in a Tris/hydrochloric-acid buffer, pH 7.5, at 37 degrees-C for about 15 hours. The mixtures were assayed for adducts using a phosphorus-32 (P-32) postlabeling technique. Five styrene-oxide/DNA adducts were detected. The overall extent of DNA modification by 5microl styrene-oxide was approximately 4.4x10(-4) adducts per nucleotide. Styrene-oxide formed five adducts with dGp and two with dAp. Thin layer chromatography of the adducts on polyethyleneimine plates showed that the styrene-oxide/DNA adducts were similar to the corresponding DNA adducts. No adducts were detected with dCp or dTp. Additionally 9L cells were treated with 1 millimolar styrene-oxide for 24 hours. The cells were examined for DNA adducts as before. Several adducts were detected; the overall extent of DNA modification by styrene-oxide amounted to 19.5x10(-6) adducts/nucleotide. The adducts seem to be similar to those formed with calf thymus DNA. The authors conclude that guanine is the major site for DNA modification by styrene-oxide. The P-32 postlabeling technique can be used to detect formation of styrene- oxide/DNA adducts.
NIOSH-Publication; NIOSH-Grant; Grants-other; Nucleic-acids; Chemical-binding; In-vitro-studies; Molecular-structure; Epoxides; Organic-chemicals; DNA-adducts
Biomedical & Environ Hlth Scis University of California School of Public Health Berkeley, CA 94720
Other Occupational Concerns; Grants-other
University of California Berkeley, Berkeley, California