Cellular Repair of DNA–DNA Cross-Links Induced by 1,2,3,4-Diepoxybutane

International Journal of Molecular Sciences

Amanda Degner¹  Bhaskar Malayappan¹  Dewakar Sangaraju¹  Susith Wickramaratne¹  Natalia Tretyakova¹  Lisa N. Chesner²  Colin Campbell²  Shira Yomtoubian² 

[1] Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455, USA;Department of Pharmacology, University of Minnesota, Minneapolis, MN 55455, USA;

关键词: interstrand DNA-DNA crosslink;    DNA repair;    Fanconi anemia;    nucleotide excision repair;    homologous recombination;    Chinese hamster lung fibroblast;    1,2,3,4-diepoxybutane;    DNA double strand break;   

DOI  :  10.3390/ijms18051086

来源: DOAJ

【 摘 要 】

Xenobiotic-induced interstrand DNA–DNA cross-links (ICL) interfere with transcription and replication and can be converted to toxic DNA double strand breaks. In this work, we investigated cellular responses to 1,4-bis-(guan-7-yl)-2,3-butanediol (bis-N7G-BD) cross-links induced by 1,2,3,4-diepoxybutane (DEB). High pressure liquid chromatography electrospray ionization tandem mass spectrometry (HPLC-ESI+-MS/MS) assays were used to quantify the formation and repair of bis-N7G-BD cross-links in wild-type Chinese hamster lung fibroblasts (V79) and the corresponding isogenic clones V-H1 and V-H4, deficient in the XPD and FANCA genes, respectively. Both V-H1 and V-H4 cells exhibited enhanced sensitivity to DEB-induced cell death and elevated bis-N7G-BD cross-links. However, relatively modest increases of bis-N7G-BD adduct levels in V-H4 clones did not correlate with their hypersensitivity to DEB. Further, bis-N7G-BD levels were not elevated in DEB-treated human clones with defects in the XPA or FANCD2 genes. Comet assays and γ-H2AX focus analyses conducted with hamster cells revealed that ICL removal was associated with chromosomal double strand break formation, and that these breaks persisted in V-H4 cells as compared to control cells. Our findings suggest that ICL repair in cells with defects in the Fanconi anemia repair pathway is associated with aberrant re-joining of repair-induced double strand breaks, potentially resulting in lethal chromosome rearrangements.

【 授权许可】

Unknown