Lazarová Monika, Slamenová Darina
Cancer Research Institute of Slovak Academy of Sciences, Laboratory of Mutagenesis and Carcinogenesis, Vlárska 7, 83391 Bratislava, Slovak Republic.
Mutat Res. 2004 Feb 14;557(2):167-75.
Genotoxicity of complex mixtures of organic compounds adsorbed onto ambient air particles (extractable organic matter, EOM) collected in Teplice (Czech Republic) as well as genotoxicity of the indirectly acting carcinogens benzo[a]pyrene (B[a]P) and 5,9-dimethyl-7H-dibenzo[c,g]carbazole (5,9-diMeDBC) was studied in human HepG2 and Caco-2 cells cultured in vitro. The level of DNA breaks was detected by conventional single-cell gel electrophoresis (alkaline comet assay). The level of DNA breaks+oxidative DNA lesions was assessed by modified single-cell gel electrophoresis. The indirectly acting chemical carcinogens studied were able to induce DNA breaks as well as oxidative DNA damage in both cell lines, but stronger DNA-damaging effects were observed in HepG2 cells, which contain a higher level of metabolic enzymes. Treatment of cells with the complex mixtures showed a dose-dependent increase of DNA breaks in HepG2 cells as well as in Caco-2 cells, with seasonal differences. Winter samples of EOM from Teplice (TP-W) were more effective in inducing DNA damage than summer samples (TP-S). Both mixtures caused significant oxidative DNA damage in HepG2 cells. The effect was less evident in cells treated with higher concentrations of TP-W, since the comet assay is limited by saturation at a higher level of DNA damage. Possible reduction of B[a]P-, 5,9-diMeDBC- or EOM-induced DNA damage by Vitamins E and C was evaluated in HepG2 cells only. Pre-treatment of these cells with either one of the vitamins considerably reduced the levels of both DNA breaks and oxidative DNA lesions induced by all compounds investigated.
研究了吸附在捷克特普利采采集的环境空气颗粒（可提取有机物，EOM）上的有机化合物复杂混合物的遗传毒性，以及间接作用致癌物苯并[a]芘（B[a]P）和5,9-二甲基-7H-二苯并[c,g]咔唑（5,9-二甲基DBC）在体外培养的人HepG2和Caco-2细胞中的遗传毒性。通过传统的单细胞凝胶电泳（碱性彗星试验）检测DNA断裂水平。通过改良的单细胞凝胶电泳评估DNA断裂+氧化性DNA损伤水平。所研究的间接作用化学致癌物能够在两种细胞系中诱导DNA断裂以及氧化性DNA损伤，但在含有较高水平代谢酶的HepG2细胞中观察到更强的DNA损伤效应。用复杂混合物处理细胞显示，HepG2细胞和Caco-2细胞中的DNA断裂呈剂量依赖性增加，且存在季节差异。特普利采的冬季EOM样本（TP-W）比夏季样本（TP-S）在诱导DNA损伤方面更有效。两种混合物均在HepG2细胞中引起显著的氧化性DNA损伤。在用较高浓度的TP-W处理的细胞中，这种效应不太明显，因为彗星试验在较高水平的DNA损伤时受到饱和度的限制。仅在HepG2细胞中评估了维生素E和C对B[a]P -、5,9-二甲基DBC -或EOM诱导的DNA损伤的可能减轻作用。用这两种维生素中的任何一种对这些细胞进行预处理，都能显著降低所有研究化合物诱导的DNA断裂和氧化性DNA损伤水平。
