title: 7-Alkylguanine adducts of styrene oxide determined by 32P-postlabeling in DNA and human embryonal lung fibroblasts (HEL).
abstract: The modified 32P-postlabeling method was used for the detection of N-7-(2-hydroxy-phenylethyl) guanine adducts in DNA and human embryonal lung (HEL) cells treated in vitro with styrene oxide (SO). The total recovery of 7-alkylguanine adducts of styrene oxide in DNA analysed by 32P-postlabeling assay was 4.1 +/- 0.6%. The disappearance of 7-alkyldeoxyguanosine monophosphate adducts from SO-modified DNA at 37 degrees C showed a half-life of 19 h. The levels of 7-alkylguanine DNA adducts and single-strand breaks (SSBs) in DNA were determined in HEL cells treated with SO for 3 and 18 h. In the 3 h treatment there was a concentration-dependent increase of both 7-alkylguanine adducts and SSBs in DNA (r = 0.98, P = 0.012 and r = 0.99, P = 0.003, respectively). We found a significant correlation between 7-alkylguanine DNA adducts and SSBs in DNA (r = 0.98, P = 0.011). In HEL cells approximately 3-fold higher levels of both 7-alkylguanine DNA adducts and SSB in DNA were found after the SO (100 microM) treatment for 3 h than after the treatment for 18 h. A significant concentration-dependent increase was found only for SSB ( r = 0.95, P = 0.024) in the 18 h treatment with SO. There was no significant correlation between 7-alkylguanine adducts and SSBs (r = 0.72, P = 0.15). Our data suggest relatively fast removal of both 7-alkylguanine adducts of SO and DNA SSBs.
authors.affiliation: Laboratory of Genetic Ecotoxicology, Regional Institute of Hygiene of Central Bohemia, Prague, Czech Republic.
authors.forename: P
authors.initials: P
authors.lastname: Vodicka
authors.forename: R
authors.initials: R
authors.lastname: Stetina
authors.forename: R
authors.initials: R
authors.lastname: Kumar
authors.forename: K
authors.initials: K
authors.lastname: Plna
authors.forename: K
authors.initials: K
authors.lastname: Hemminki
mesh_terms: D001345:Autoradiography; D002460:Cell Line; D002851:Chromatography, High Pressure Liquid; D018736:DNA Adducts; D004277:DNA, Single-Stranded / Q000187:drug effects*; D004852:Epoxy Compounds / Q000633:toxicity*; D006801:Humans; D008168:Lung / Q000166:cytology / Q000187:drug effects / Q000196:embryology; D009153:Mutagens / Q000633:toxicity*; D010761:Phosphorus Radioisotopes; D013056:Spectrophotometry, Ultraviolet
chemical_list: D018736:DNA Adducts; D004277:DNA, Single-Stranded; D004852:Epoxy Compounds; D009153:Mutagens; D010761:Phosphorus Radioisotopes; C013690:styrene oxide