Laboratory of Genetic Ecotoxicology, Institute of Experimental Medicine AS CR, Prague 4, Czech Republic.
Mutat Res. 2010 Feb;696(2):114-21. doi: 10.1016/j.mrgentox.2009.12.018. Epub 2010 Jan 14.
We investigated the role of oxidative damage in the mechanism of action of selected individual carcinogenic PAHs (c-PAHs: benzo[a]pyrene, B[a]P; dibenzo[a,l]pyrene, DB[a,l]P), an artificial mixture of c-PAHs (c-PAHs mix) and extractable organic matter (EOM) from urban air particulate matter (PM). Two cell lines (human hepatoma cells, HepG2; human diploid lung fibroblasts, HEL) were treated for 24 and 48h with various concentrations of compounds and mixtures. A panel of oxidative stress markers included 8-oxodeoxyguanosine (8-oxodG), 15-F(2t)-isoprostane (15-F(2t)-IsoP) and protein carbonyl groups. The response of the cell lines to the test compounds was substantially different. In HepG2 cells, oxidative damage to DNA was generally not induced by individual c-PAHs and the c-PAHs mix, but EOM increased 8-oxodG levels in these cells. In HEL cells, none of the compounds induced oxidative DNA damage. Lipid peroxidation, measured as the level of 15-F(2t)-IsoP, was induced by c-PAHs in HepG2 cells only after 48h of incubation, while the effect of EOM was detected already after 24h. In HEL cells, individual c-PAHs and the c-PAH mix generally decreased 15-F(2t)-IsoP levels. This effect was even stronger for EOM treatment. Protein oxidation, assessed as carbonyl levels in cell lysates, was not induced after 24h of treatment with any compound in either cell line. Individual c-PAHs and the c-PAH mix generally induced protein oxidation in both cell lines after 48h treatment, with the exception of DB[a,l]P in HepG2 cells. Oxidative damage to proteins caused by EOM was generally increased in HepG2 cells after 48h of incubation, while in HEL cells the effect was observed for only one dose of EOM. In summary, our results demonstrate the ability of EOM to induce oxidative damage to DNA and lipids after 24h of treatment, and to proteins after 48h, in HepG2 cells, while the effect of c-PAHs was substantially less. The induction of oxidative stress by c-PAHs and EOM in HEL cells was weak.
我们研究了氧化损伤在选定的个别致癌多环芳烃（c-PAHs：苯并[a]芘，B[a]P；二苯并[a,l]芘，DB[a,l]P）、c-PAHs 混合物（c-PAHs mix）和城市空气颗粒物（PM）中可提取有机物（EOM）作用机制中的作用。我们用不同浓度的化合物和混合物处理两种细胞系（人肝癌细胞，HepG2；人二倍体肺成纤维细胞，HEL）24 小时和 48 小时。一组氧化应激标志物包括 8-氧脱氧鸟苷（8-oxodG）、15-F(2t)-异前列腺素（15-F(2t)-IsoP）和蛋白质羰基。细胞系对测试化合物的反应有很大的不同。在 HepG2 细胞中，单个 c-PAHs 和 c-PAHs 混合物一般不会引起 DNA 氧化损伤，但 EOM 会增加这些细胞中 8-oxodG 的水平。在 HEL 细胞中，没有一种化合物能诱导 DNA 氧化损伤。脂质过氧化，以 15-F(2t)-IsoP 的水平来衡量，仅在 HepG2 细胞孵育 48 小时后才被 c-PAHs 诱导，而 EOM 的作用在 24 小时后就被检测到。在 HEL 细胞中，个别 c-PAHs 和 c-PAH 混合物通常会降低 15-F(2t)-IsoP 的水平。EOM 处理的效果更强。用任何化合物处理 24 小时后，在两种细胞系中均未诱导蛋白质氧化，评估方法为细胞裂解物中的羰基水平。24 小时后，个别 c-PAHs 和 c-PAH 混合物通常会诱导两种细胞系中的蛋白质氧化，HepG2 细胞中的 DB[a,l]P 除外。EOM 在 HepG2 细胞中孵育 48 小时后，通常会增加蛋白质氧化引起的氧化损伤，而在 HEL 细胞中，只有一种剂量的 EOM 观察到这种作用。总之，我们的结果表明，EOM 在 HepG2 细胞中，24 小时后即可诱导 DNA 和脂质氧化损伤，48 小时后即可诱导蛋白质氧化损伤，而 c-PAHs 的作用则小得多。c-PAHs 和 EOM 对 HEL 细胞中氧化应激的诱导作用较弱。
