title: 1,2,3,4-Diepoxybutane-induced DNA-protein cross-linking in human fibrosarcoma (HT1080) cells.
abstract: 1,2,3,4-Diepoxybutane (DEB) is the key carcinogenic metabolite of 1,3-butadiene (BD), an important industrial and environmental chemical present in urban air and in cigarette smoke. DEB is a genotoxic bis-electrophile capable of cross-linking cellular biomolecules to form DNA-DNA and DNA-protein cross-links (DPCs). In the present work, mass spectrometry-based proteomics was employed to characterize DEB-mediated DNA-protein cross-linking in human fibrosarcoma (HT1080) cells. Over 150 proteins including histones, high mobility group proteins, transcription factors, splicing factors, and tubulins were found among those covalently cross-linked to chromosomal DNA in the presence of DEB. A large portion of the cross-linked proteins are known factors involved in DNA binding, transcriptional regulation, cell signaling, DNA repair, and DNA damage response. HPLC-ESI(+)-MS/MS analysis of total proteolytic digests revealed the presence of 1-(S-cysteinyl)-4-(guan-7-yl)-2,3-butanediol conjugates, confirming that DEB forms DPCs between cysteine thiols within proteins and the N-7 guanine positions within DNA. However, relatively high concentrations of DEB were required to achieve significant DPC formation, indicating that it is a poor cross-linking agent as compared to antitumor nitrogen mustards and platinum compounds.
authors.affiliation: Department of Medicinal Chemistry and Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota 55455, USA.
authors.forename: Teshome B
authors.initials: TB
authors.lastname: Gherezghiher
authors.forename: Xun
authors.initials: X
authors.lastname: Ming
authors.forename: Peter W
authors.initials: PW
authors.lastname: Villalta
authors.forename: Colin
authors.initials: C
authors.lastname: Campbell
authors.forename: Natalia Y
authors.initials: NY
authors.lastname: Tretyakova
mesh_terms: D000595:Amino Acid Sequence; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D003432:Cross-Linking Reagents / Q000737:chemistry* / Q000494:pharmacology; D004247:DNA / Q000737:chemistry / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism; D004852:Epoxy Compounds / Q000737:chemistry* / Q000494:pharmacology; D005354:Fibrosarcoma; D015894:Genome, Human; D006801:Humans; D058977:Molecular Sequence Annotation; D011485:Protein Binding; D020543:Proteome / Q000737:chemistry* / Q000378:metabolism; D040901:Proteomics; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry
chemical_list: D003432:Cross-Linking Reagents; D004268:DNA-Binding Proteins; D004852:Epoxy Compounds; D020543:Proteome; C007366:diepoxybutane; D004247:DNA