Nonhomologous DNA end joining and chromosome aberrations in human embryonic lung fibroblasts treated with environmental pollutants.
In order to evaluate the ability of a representative polycyclic aromatic hydrocarbon (PAH) and PAH-containing complex mixtures to induce double strand DNA breaks (DSBs) and repair of damaged DNA in human embryonic lung fibroblasts (HEL12469 cells), we investigated the effect of benzo[a]pyrene (B[a]P) and extractable organic matter (EOM) from ambient air particles <2.5μm (PM2.5) on nonhomologous DNA end joining (NHEJ) and induction of stable chromosome aberrations (CAs). PM2.5 was collected in winter and summer 2011 in two Czech cities differing in levels and sources of air pollutants. The cells were treated for 24h with the following concentrations of tested chemicals: B[a]P: 1μM, 10μM, 25μM; EOMs: 1μg/ml, 10μg/ml, 25μg/ml. We tested several endpoints representing key steps leading from DSBs to the formation of CAs including histone H2AX phosphorylation, levels of proteins Ku70, Ku80 and XRCC4 participating in NHEJ, in vitro ligation activity of nuclear extracts of the HEL12469 cells and the frequency of stable CAs assessed by whole chromosome painting of chromosomes 1, 2, 4, 5, 7 and 17 using fluorescence in situ hybridization. Our results show that 25μM of B[a]P and most of the tested doses of EOMs induced DSBs as indicated by H2AX phosphorylation. DNA damage was accompanied by induction of XRCC4 expression and an increased frequency of CAs. Translocations most frequently affected chromosome 7. We observed only a weak induction of Ku70/80 expression as well as ligation activity of nuclear extracts. In summary, our data suggest the induction of DSBs and NHEJ after treatment of human embryonic lung fibroblasts with B[a]P and complex mixtures containing PAHs.
Department of Genetic Ecotoxicology, Institute of Experimental Medicine AS CR, Prague, Czech Republic. Electronic address: prossner@biomed.cas.cz.
Pavel
P
Rossner
Department of Genetic Ecotoxicology, Institute of Experimental Medicine AS CR, Prague, Czech Republic.
Andrea
A
Rossnerova
Department of Genetic Ecotoxicology, Institute of Experimental Medicine AS CR, Prague, Czech Republic.
Olena
O
Beskid
Department of Genetic Ecotoxicology, Institute of Experimental Medicine AS CR, Prague, Czech Republic.
Nana
N
Tabashidze
Department of Genetic Ecotoxicology, Institute of Experimental Medicine AS CR, Prague, Czech Republic.
Helena
H
Libalova
Department of Genetic Ecotoxicology, Institute of Experimental Medicine AS CR, Prague, Czech Republic.
Katerina
K
Uhlirova
Department of Genetic Ecotoxicology, Institute of Experimental Medicine AS CR, Prague, Czech Republic.
Jan
J
Topinka
Department of Genetic Ecotoxicology, Institute of Experimental Medicine AS CR, Prague, Czech Republic.
Radim J
RJ
Sram
D034961:Antigens, Nuclear / Q000235:genetics / Q000378:metabolism; D001564:Benzo(a)pyrene / Q000633:toxicity*; D002460:Cell Line; D002877:Chromosomes, Human / Q000235:genetics / Q000378:metabolism*; D018153:Czech Republic; D059766:DNA End-Joining Repair / Q000187:drug effects* / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004622:Embryo, Mammalian / Q000378:metabolism* / Q000473:pathology; D004785:Environmental Pollutants / Q000633:toxicity*; D005347:Fibroblasts / Q000378:metabolism* / Q000473:pathology; D006657:Histones / Q000235:genetics / Q000378:metabolism; D006801:Humans; D000072200:Ku Autoantigen; D008168:Lung / Q000378:metabolism* / Q000473:pathology; D052638:Particulate Matter; D010766:Phosphorylation / Q000187:drug effects / Q000235:genetics; D014178:Translocation, Genetic / Q000187:drug effects*; D014506:Urban Renewal
D034961:Antigens, Nuclear; D004268:DNA-Binding Proteins; D004785:Environmental Pollutants; C468783:H2AX protein, human; D006657:Histones; D052638:Particulate Matter; C101467:XRCC4 protein, human; D001564:Benzo(a)pyrene; C000606509:Xrcc6 protein, human; D000072200:Ku Autoantigen
Benzo[a]pyrene; Chromosome aberrations; Double-strand DNA breaks; Extractable organic matter; Nonhomologous DNA end joining repair