Genotoxic effects of benzo[a]pyrene and dibenzo[a,l]pyrene in a human lung cell line.
Several studies have shown that polycyclic aromatic hydrocarbons (PAHs) produce genotoxic effects in assays performed in vivo and in vitro. This study was undertaken to investigate the ability of benzo[a]pyrene (BP) and dibenzo[a,l]pyrene (DBP) to induce DNA damage in a human lung fibroblast cell line (MRC-5), using sister-chromatid exchanges test (SCEs), the comet assay, and evaluating point mutations in codon 12 of the K-ras protooncogene by polymerase chain reaction-single-strand conformation polymorphisms (PCR-SSCPs) and restriction fragment length polymorphisms (RFLP)-enriched PCR methods. Sister-chromatid exchanges frequencies were significantly increased in cells exposed to benzo[a]pyrene and dibenzo[a,l]pyrene in relation to controls (p < .001). Using the standard alkaline comet assay, significant differences between groups were found for the variable comet moment (CM) when cells were exposed to BP (p < .001) and DBP (p < .001). Nevertheless, PCR-SSCP and RFLP-enriched PCR methods did not show any association between treatments with BP and DBP and K-ras point mutations. The data presented in this study indicated that BP and DBP induced both DNA strand breaks and sister-chromatid exchanges but not significant point mutations at codon 12 of K-ras gene in the MRC-5 cell line.
Mourón
Silvana Andrea
SA
Centro de Investigaciones en Genética Básica y Aplicada (CIGEBA), Facultad de Ciencias Veterinarias, Universidad Nacional de La Plata, La Plata, Argentina.
Grillo
Claudia Alejandra
CA
Dulout
Fernando Noel
FN
Golijow
Carlos Daniel
CD
D001564:Benzo(a)pyrene / Q000633:toxicity*; D001580:Benzopyrenes / Q000633:toxicity*; D002460:Cell Line; D020552:Comet Assay; D004247:DNA / Q000187:drug effects*; D004249:DNA Damage; D005347:Fibroblasts / Q000187:drug effects* / Q000473:pathology; D005786:Gene Expression Regulation / Q000187:drug effects; D011905:Genes, ras / Q000187:drug effects / Q000235:genetics; D006801:Humans; D008168:Lung / Q000166:cytology; D009153:Mutagens / Q000633:toxicity*; D017354:Point Mutation / Q000187:drug effects; D012150:Polymorphism, Restriction Fragment Length; D018807:Polymorphism, Single-Stranded Conformational; D012854:Sister Chromatid Exchange / Q000187:drug effects
D001580:Benzopyrenes; D009153:Mutagens; D001564:Benzo(a)pyrene; D004247:DNA; C041517:dibenzo(a,l)pyrene