Topinka J, Sevastyanova O, Binkova B, Chvatalova I, Milcova A, Lnenickova Z, Novakova Z, Solansky I, Sram R J
Laboratory of Genetic Ecotoxicology, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic and the Health Institute of Central Bohemia, Vídenská 1083, 142 20 Prague 4, Czech Republic.
Mutat Res. 2007 Nov 1;624(1-2):9-17. doi: 10.1016/j.mrfmmm.2007.02.032. Epub 2007 Apr 19.
The effect of exposure to organic compounds adsorbed onto respirable air particles (<2.5microm) on DNA adducts in lymphocytes was studied in a group of non-smoking policemen (N=109, aged 35+/-0.9 years) working in the downtown area of Prague and spending >8h daily outdoors. Personal exposure to carcinogenic polycyclic aromatic hydrocarbons (c-PAHs) adsorbed on respirable particles was monitored in each subject for 48h before biological sampling. DNA adducts were analyzed by a (32)P-postlabelling assay, and total DNA adduct levels and B[a]P-like spots were determined. Further biomarkers included cotinine levels in urine to control for exposure to tobacco smoke, plasma levels of vitamins A, E and C and polymorphisms of metabolic genotypes (GSTM1, GSTP1, GSTT1, CYP 1A1-Msp I and Ile/Val, MTHFR, MS), DNA repair genotypes (XRCC1, hOGG1 and XPD exons 6 and 23) and the p53 gene (p53 Msp I and BstU I). All the biomarkers of exposure and effect were analyzed repeatedly during a period of one year at 2-3 month intervals (January, March, June, September 2004) to cover periods with high (winter) and low (summer) levels of air pollution. The highest personal exposure to c-PAHs was found in January (8.1+/-8.8ng/m(3)), while the other three sampling periods exhibited 3-4-fold lower c-PAH exposure. The total DNA adducts were only slightly elevated in January (2.08+/-1.60) compared to March (1.66+/-0.65), June (1.96+/-1.73) and September (1.77+/-1.77). B[a]P-like DNA adducts, however, were significantly higher in January than in the March and June sampling periods (0.26+/-0.14 vs. 0.19+/-0.12 and 0.22+/-0.13, respectively; p<0.0001 and p=0.017) indicating that c-PAH exposure probably plays a crucial role in DNA adduct formation in lymphocytes. No effect of individual metabololic or DNA repair genotypes on DNA adduct levels was observed. However, the combination of two genotypes encoding enzymes metabolizing c-PAHs - CYP 1A1 and GSTM1 - was associated with the levels of total and B[a]P-like DNA adducts under conditions of increased exposure to c-PAHs. Our study suggests that DNA adducts in the lymphocytes of subjects exposed to increased c-PAH levels are an appropriate biomarker of a biologically effective dose, directly indicating whether or not the extent of exposure to these compounds is related to an increased mutagenic and carcinogenic risk.
在一组非吸烟警察（N = 109，年龄35±0.9岁）中，研究了暴露于吸附在可吸入空气颗粒（<2.5微米）上的有机化合物对淋巴细胞中DNA加合物的影响。这些警察在布拉格市中心工作，每天在户外工作超过8小时。在进行生物采样前，对每个受试者个人暴露于吸附在可吸入颗粒上的致癌多环芳烃（c-PAHs）的情况进行了48小时监测。通过32P后标记分析法分析DNA加合物，并测定总DNA加合物水平和B[a]P样斑点。其他生物标志物包括尿中可替宁水平以控制烟草烟雾暴露、血浆中维生素A、E和C水平以及代谢基因型（GSTM1、GSTP1、GSTT1、CYP 1A1-Msp I和Ile/Val、MTHFR、MS）、DNA修复基因型（XRCC1、hOGG1和XPD外显子6和23）以及p53基因（p53 Msp I和BstU I）的多态性。在一年时间内，每隔2 - 3个月（2004年1月、3月、6月、9月）对所有暴露和效应的生物标志物进行重复分析，以涵盖空气污染水平高（冬季）和低（夏季）的时期。1月份发现个人暴露于c-PAHs的水平最高（8.1±8.8 ng/m³），而其他三个采样期的c-PAH暴露水平低3 - 4倍。与3月（1.66±0.65）、6月（1.96±1.73）和9月（1.77±1.77）相比，1月份总DNA加合物仅略有升高（2.08±1.60）。然而，1月份B[a]P样DNA加合物显著高于3月和6月的采样期（分别为0.26±0.14 vs. 0.19±0.12和0.22±0.13；p<0.0001和p = 0.017），表明c-PAH暴露可能在淋巴细胞DNA加合物形成中起关键作用。未观察到个体代谢或DNA修复基因型对DNA加合物水平有影响。然而，在暴露于c-PAHs增加的情况下，编码代谢c-PAHs酶的两种基因型——CYP 1A1和GSTM1——的组合与总DNA加合物和B[a]P样DNA加合物水平相关。我们的研究表明，暴露于c-PAH水平升高的受试者淋巴细胞中的DNA加合物是生物有效剂量的合适生物标志物，直接表明这些化合物的暴露程度是否与诱变和致癌风险增加有关。
