Rejoining of DNA strand breaks induced by propylene oxide and epichlorohydrin in human diploid fibroblasts

✍ Scribed by Miroslav Chovanec; Maria Näslund; Irina Spivak; Maria Dušinská; Björn Cedervall; Ada Kolman

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 153 KB
• Volume: 32
• Category: Article
• ISSN: 0893-6692
• DOI: 10.1002/(sici)1098-2280(1998)32:3<223::aid-em4>3.0.co;2-9

✦ Synopsis

The repair kinetics of DNA single-and double-PO, respectively, were rejoined within 4 hr after the strand breaks (SSBs, DSBs) induced with two carcin-treatment (a half-life of Ç2.5 hr), with little further ogenic epoxides, propylene oxide (PO) and epichl-repair thereafter. At lower dose of ECH (1 mMh) a orohydrin (ECH), was studied in human diploid fi-half-life for DSBs rejoining was estimated to be Ç2 broblasts. The methods used were: alkaline DNA hr; however, only 29% of DSBs were rejoined unwinding (ADU), the comet assay, and pulsed field within 2 hr at the higher dose of 2 mMh. After 18 gel electrophoresis (PFGE). About 70% of SSBs, hr, the rejoining following treatment with a lower measured by ADU, were rejoined after the treat-dose was negligible. At a higher dose, a rapid acment with 5 mMh and 10 mMh of PO within 20 hr, cumulation of DSBs was observed, probably as the and the half-life was estimated to be Ç15 hr. On result of cell death and DNA degradation. The rethe other hand, effective rejoining of SSBs after ECH sults demonstrate the capability of human diploid treatment was observed only at a dose of 1 mMh (a fibroblasts to repair DNA SSBs and DSBs at low-tohalf-life of Ç15 hr), whereas after 2 mMh treatment, moderate doses of the epoxides. A weak capacity only 26% of SSBs could be rejoined within 20 hr. to rejoin DNA strand breaks induced by higher Furthermore, the use of the comet assay demon-doses of ECH may be a consequence of its higher strated that DNA strand breaks were effectively re-DNA alkylation activity and approximately 10 times joined after PO and ECH treatment at doses of 5-higher toxicity compared to PO.