The cellular response to genotoxic treatment depends on the cell line used. Although tumor cell lines are widely used for genotoxicity tests, the interpretation of the results may be potentially hampered by changes in cellular processes caused by malignant transformation. In our study we used normal human embryonic lung fibroblasts (HEL12469 cells) and tested their response to treatment with benzo[a]pyrene (B[a]P) and extractable organic matter (EOM) from ambient air particles <2.5 µm (PM2.5) collected in two Czech cities differing in levels and sources of air pollution. We analyzed multiple endpoints associated with exposure to polycyclic aromatic hydrocarbons (PAHs) including the levels of bulky DNA adducts and the nucleotide excision repair (NER) response [expression of XPE, XPC and XPA genes on the level of mRNA and proteins, unscheduled DNA synthesis (UDS)]. EOMs were collected in the winter and summer of 2011 in two Czech cities with different levels and sources of air pollution. The effects of the studied compounds were analyzed in the presence (+S9) and absence (-S9) of the rat liver microsomal S9 fraction. The levels of bulky DNA adducts were highest after treatment with B[a]P, followed by winter EOMs; their induction by summer EOMs was weak. The induction of both mRNA and protein expression was observed, with the most pronounced effects after treatment with B[a]P (-S9); the response induced by EOMs from both cities and seasons was substantially weaker. The expression of DNA repair genes was not accompanied by the induction of UDS activity. In summary, our results indicate that the tested compounds induced low levels of DNA damage and affected the expression of NER genes; however, nucleotide excision repair was not induced.

• MeSH
• adukty DNA MeSH
• buněčné linie MeSH
• DNA vazebné proteiny genetika   metabolismus   MeSH
• fibroblasty účinky léků   metabolismus   MeSH
• látky znečišťující vzduch chemie   toxicita   MeSH
• látky znečišťující životní prostředí chemie   toxicita   MeSH
• lidé MeSH
• messenger RNA genetika   MeSH
• oprava DNA * MeSH
• pevné částice chemie   toxicita   MeSH
• plíce MeSH
• polycyklické aromatické uhlovodíky chemie   toxicita   MeSH
• proliferace buněk účinky léků   MeSH
• regulace genové exprese účinky léků   MeSH
• xeroderma pigmentosum - protein skupiny A genetika   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The effects of the lesions induced by single, site-specific 1,2-GG or 1,3-GTG intrastrand adducts of cis-diamminedichloroplatinum(II) formed in oligodeoxyribonucleotide duplexes on energetics of DNA were examined by means of differential scanning calorimetry. These effects were correlated with affinity of these duplexes for damaged-DNA binding-proteins XPA and RPA; this affinity was examined by gel electrophoresis. The results confirm that rigid DNA bending is the specific determinant responsible for high-affinity interactions of XPA with damaged DNA, but that an additional important factor, which affects affinity of XPA to damaged DNA, is a change of thermodynamic stability of DNA induced by the damage. In addition, the results also confirm that RPA preferentially binds to DNA distorted so that hydrogen bonds between complementary bases are interrupted. RPA also binds to non-denaturational distortions in double-helical DNA, but affinity of RPA to these distortions is insensitive to alterations of thermodynamic stability of damaged DNA.

• MeSH
• diferenciální skenovací kalorimetrie MeSH
• DNA vazebné proteiny chemie   metabolismus   MeSH
• DNA chemie   metabolismus   MeSH
• financování organizované MeSH
• konformace nukleové kyseliny MeSH
• poškození DNA MeSH
• replikační protein A chemie   metabolismus   MeSH
• sekvence nukleotidů MeSH
• termodynamika MeSH
• vazebná místa MeSH
• vodíková vazba MeSH
• xeroderma pigmentosum - protein skupiny A chemie   metabolismus   MeSH