title: Mechanistic relationships between hepatic genotoxicity and carcinogenicity in male B6C3F1 mice treated with polycyclic aromatic hydrocarbon mixtures.
abstract: The genotoxicity of a complex mixture [neutral fraction (NF)] from a wood preserving waste and reconstituted mixture (RM) mimicking the NF with seven major polycyclic aromatic hydrocarbons (PAHs) and benzo(a)pyrene (BaP) was investigated by determining DNA adducts and tumor incidence in male B6C3F1 mice exposed to three different doses of the chemical mixtures. The peak values of DNA adducts were observed after 24 h, and the highest levels of PAH-DNA adducts were exhibited in mice administered NF + BaP, and the highest tumor incidence and mortality were also observed in this group. DNA adduct levels after 1, 7, or 21 days were significantly correlated with animal mortality and incidence of total tumors including liver, lung, and forestomach. However, only hepatic DNA adducts after 7 days significantly correlated with liver tumor incidence. Most proteins involved in DNA repair including ATM, pATR, Chk1, pChk1, DNA PKcs, XRCC1, FANCD2, Ku80, Mre11, and Brca2 were significantly lower in liver tumor tissue compared to non-tumor tissue. Expressions of proteins involved in apoptosis and cell cycle regulation were also significantly different in tumor versus non-tumor tissues, and it is possible that PAH-induced changes in these gene products are important for tumor development and growth.
authors.affiliation: College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, 77843, USA.
authors.forename: Tracie D
authors.initials: TD
authors.lastname: Phillips
authors.forename: Molly
authors.initials: M
authors.lastname: Richardson
authors.forename: Yi-Shing Lisa
authors.initials: YS
authors.lastname: Cheng
authors.forename: Lingyu
authors.initials: L
authors.lastname: He
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: McDonald
authors.forename: Leslie H
authors.initials: LH
authors.lastname: Cizmas
authors.forename: Stephen H
authors.initials: SH
authors.lastname: Safe
authors.forename: Kirby C
authors.initials: KC
authors.lastname: Donnelly
authors.forename: Fen
authors.initials: F
authors.lastname: Wang
authors.forename: Bhagavatula
authors.initials: B
authors.lastname: Moorthy
authors.forename: Guo-Dong
authors.initials: GD
authors.lastname: Zhou
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D001564:Benzo(a)pyrene / Q000737:chemistry / Q000633:toxicity; D002453:Cell Cycle / Q000187:drug effects / Q000235:genetics; D018736:DNA Adducts / Q000378:metabolism*; D004260:DNA Repair; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D005786:Gene Expression Regulation / Q000187:drug effects; D008099:Liver / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D008114:Liver Neoplasms, Experimental / Q000139:chemically induced* / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D008297:Male; D008815:Mice, Inbred Strains; D015394:Molecular Structure; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry / Q000633:toxicity*; D014866:Waste Products / Q000009:adverse effects / Q000032:analysis
chemical_list: D018736:DNA Adducts; D011084:Polycyclic Aromatic Hydrocarbons; D014866:Waste Products; D001564:Benzo(a)pyrene