[Association between polymorphisms of metabolic genes and telomere length in workers exposed to polycyclic aromatic hydrocarbon].

OBJECTIVE: To investigate the association between the polymorphisms of metabolic genes and telomere length of genomic DNA in peripheral blood of workers exposed to polycyclic aromatic hydrocarbons (PAHs). METHODS: One hundred and forty five coke-oven workers exposed to PAHs and sixty eight non-exposed medical staffs were recruited in this study. Urinary 1-hydroxypyrene (1-OHP) served as the internal exposure dose of PAHs for all subjects. Relative telomere length (RTL) of genomic DNA in peripheral blood was used as telomere length and measured by real-time PCR. Polymorphisms of metabolic genes were detected by PCR-based methods. RESULTS: Compared with control group, the exposure group shown a decreased RTL (1.10 +/- 0.75 vs 1.43 +/- 1.06, P < 0.05). In the coke-oven workers, after adjusting the sex, age, cigarettes per day and urinary 1-OHP, RTL (1.25 +/- 0.93) of workers with CT genotype at the CYP1A1 3801 T > C was significantly longer than that (0.93 +/- 0.51) of workers with TT genotype (P < 0.05). RTL (0.90 +/- 0.58) of individuals with the Tyr/His genotype at mEH Tyr113His was significantly shorter than that (1.24 +/- 0.90) of individuals with the Tyr/Tyr genotype (P < 0.05). RTL (1.02 +/- 0.64) of individuals with the CT genotype at AHR rs10250822 was significantly shorter than that (1.36 +/- 1.14) of individuals with the CC genotype (P < 0.05). RTL (0.93 +/- 0.54) of individuals with the AT genotype at AHR rs10247158 was significantly shorter than that (1.19 +/- 0.84) of individuals with the AA genotype (P < 0.05). CONCLUSION: The results of present study suggested that PAHs exposure could induce the shorted RTL, CYP1A1, mEH, AHR polymorphisms might influence the change of telomere length of genomic DNA in peripheral blood of workers exposed to PAHs.

[Association between telomere length and occupational polycyclic aromatic hydrocarbons exposure].

OBJECTIVE: To explore the association between polycyclic aromatic hydrocarbons (PAHs) exposure and telomere length (TL), so as to investigate the effective biomarkers to evaluate the genetic damage in peripheral blood of workers exposed to PAHs. METHODS: The exposure group consisted of 145 coke-oven workers (including 30 top-oven workers, 76 side-oven workers and 39 bottom-oven workers), and the non-exposure control group comprised 68 medical staffs. At 6 hours after the weekend duty shift, the samples of urine and 1 ml venous blood were collected from each subject. Airborne benzene-soluble matter (BSM) and particulate-phase B(a)P in the working environment of coke-oven and controls were sampled and analyzed. The concentration of urinary 1-hydroxypyrene (1-OHPyr) was determined. A real-time PCR method was used to determine the relative telomere length (RTL) of genomic DNA in peripheral blood. The relationship between the RTL and external exposure of PAHs, the potential factors which might have influence on TL were analyzed. RESULTS: The medians of air BSM and particulate-phase B(a)P were higher in coke-oven (BSM: 328.6 µg/m(3); B(a)P: 926.9 ng/m(3)) than those in control working environment (BSM:97.8 µg/m(3); B(a)P: 49.1 ng/m(3)). The level of 1-OHPyr among coke-oven workers was significantly higher than that of non-exposed group (12.2 µmol/mol Cr vs 0.7 µmol/mol Cr; t = 26.971, P < 0.01). RTL in coke-oven workers were significantly shorter than those of controls (1.10 ± 0.75 vs 1.43 ± 1.06; t = 2.263, P = 0.026), and after adjusting for cigarettes per day and urinary 1-OHPyr, the significant difference was still observed (F(adju) = 5.496, P(adju) = 0.020). Stratification analysis found that RTL among the male and non-drinking groups in coke-oven workers were shorter than those the same sex and alcohol using status in controls (1.08 ± 0.73 vs 1.51 ± 1.10, F = 9.212, P = 0.003; 0.96 ± 0.38 vs 1.26 ± 0.46, F = 6.484, P = 0.012). Significant correlation between RTL and age was found (r = -0.284, P = 0.019) in non-exposure group. CONCLUSION: PAH-exposure has effect on TL of genomic DNA in peripheral blood, which is mainly observed in the male and non-drinking groups between PAH-exposed workers and controls. It indicates that TL of genomic DNA in peripheral blood might be an effective biomarker as PAH-induced genetic damage.

[Using HPLC-MS/MS method to analyze monohydroxy metabolites of PAHs in urine].

OBJECTIVE: To establish a HPLC-MS/MS method for the simultaneous determination of 4 monohydroxy metabolites of polycyclic aromatic hydrocarbons (PAHs) in urine, including 1-naphthol, 2-naphthol, 3-phenanthrol and 1-pyrenol). METHODS: After being treated by enzymatic hydrolysis, urine samples were purified by liquid-liquid extraction, evaporated under nitrogen to constant volume and examined by HPLC-MS/MS. Target compounds were quantified by internal standard calibration curve. RESULTS: The reproducibility and precision were improved by internal standard calibration. The recovery of four target compounds were in the range of 89.7%-103.0%. The precision of intra- and inter-batch was 1.0%-4.2% and 1.8%-5.8% respectively. The limits of quantification was 0.2 microg/L for 1-naphthol, 2-naphthol and 1-pyrenol and the limits of quantification was 0.1 microg/L for 3-phenanthrol. CONCLUSION: The sensitivity, reproducibility and recovery of HPLC-MS/MS method were good for the analysis of 1-naphthol, 2-naphthol, 3-phenanthrol and 1-pyrenol in the urine of people on occupational and nonoccupational exposure to PAHs.

Biomarkers measured by cytokinesis-block micronucleus cytome assay for evaluating genetic damages induced by polycyclic aromatic hydrocarbons.

Coke oven workers are regularly exposed to polycyclic aromatic hydrocarbons (PAHs) and have a high risk for lung cancer. Limited evidence has demonstrated a direct link between exposure to PAHs and early genetic damage in exposed workers. The cytokinesis-block micronucleus (CBMN) cytome assay is a comprehensive system for measuring DNA damage and cytotoxicity. In the current study, we investigated different chromosomal damage endpoints including micronuclei (MN), nucleoplasmic bridges (NPBs) and nuclear buds (NBUDs), in 141 PAH-exposed subjects and 66 unexposed controls. The frequencies of MN, NPBs and NBUDs were all significantly higher in PAH-exposed workers than in controls (2.4-, 5-, and 3-fold, respectively). We further classified the PAH-exposed workers into different PAHs exposure groups based on their work positions on the oven and their urinary 1-hydroxypyrene and found that the frequencies of NPBs and NBUDs increased with the increasing level of both external and internal PAHs exposure levels. Similar trend was not found for MN due to the reduced MN frequency in the highest PAHs exposure group compared with the second highest PAHs exposure group. Using principal component analysis, we confirmed that the frequencies of NPBs and NBUDs are more sensitive to reflect the external or internal levels of PAHs exposure. In PAH-exposed subjects, NPB and NBUD frequencies were influenced by gender and females have lower frequencies of NPB and NBUD. Taken together, our observations indicate that NPBs and NBUDs are more sensitive and reliable biomarkers for genetic damages induced by PAHs and could potentially be used for the biomonitoring of genotoxin-exposed populations.

Uridine diphosphoglucuronosyltransferase 1A7 gene polymorphism and susceptibility to chromosomal damage among polycyclic aromatic hydrocarbons exposed workers.

OBJECTIVE: The aim of this study was to explore the relationship between UGT1A7 gene polymorphisms and susceptibility to chromosomal damage among polycyclic aromatic hydrocarbons (PAH)-exposed workers. METHODS: Blood and urine samples of 140 PAH-exposed workers and 66 non-PAH-exposed workers were collected. The polymorphisms of UGT1A7, cytokinesis-block micronucleus (CBMN) and 1-hydroxypyrene were analyzed. RESULTS: UGT1A7 codon 208 Arg carriers exhibited significantly higher CBMN frequencies than did the Trp/Trp (P < 0.05). Stratification analysis revealed that the significant association between CBMN frequencies and the polymorphisms of UGT1A7 Asn129Lys, Arg131Lys, and Trp208Arg was most pronounced. Moreover, higher CBMN frequencies were found among subjects with *3 allele than those with *1 allele (P = 0.008) in younger PAH-exposed workers. CONCLUSION: Polymorphisms of UGT1A7 gene may alter the severity of PAH-induced chromosomal damage among the exposed workers.

Antaxia-telangiectasia mutated gene polymorphisms and susceptibility to chromosomal damage among polycyclic aromatic hydrocarbons exposed workers.

The aim was to explore the relationship between the ataxia-telangiectasia mutated (ATM) gene polymorphisms and susceptibility to cytokinesis-block micronucleus among workers exposed to polycyclic aromatic hydrocarbons (PAH). Blood and urine samples of 140 PAH-exposed workers and 66 non-PAH-exposed workers were collected. Seven tagging single nucleotide polymorphisms in ATM gene were selected by pariwise r(2) method and minor allele frequency cutoff of 0.05 from Chinese genotype data in HapMap project. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to analyze the polymorphisms of ATM rs600931, rs652311, rs227060, rs227292, rs624366, rs189037 and rs228589. The results showed that ATM rs600931 AG and AG+AA genotypes exhibited significantly higher cytokinesis-block micronucleus (CBMN) frequency (11.14+/-6.91 per thousand and 10.57+/-6.82 per thousand) than did the GG genotype (7.66+/-5.69 per thousand, P=0.015 and 0.038, respectively). The subjects with rs189037 GA and GA+AA genotypes exhibited significantly higher CBMN frequency (10.99+/-6.90 per thousand and 10.51+/-6.76 per thousand) than that of the GG genotype (7.72+/-5.82 per thousand, P=0.018 and 0.035, respectively). The PAH-exposed workers with rs624366 GC and GC+CC genotypes exhibited significantly higher CBMN frequency (11.34+/-6.74 per thousand and 10.73+/-6.62 per thousand) than did the GG genotype (7.61+/-6.07 per thousand, P=0.001 and 0.003, respectively). rs227092 GT genotype exhibited significantly higher CBMN frequency (10.78+/-6.60 per thousand) than did the GG genotype (7.91+/-6.30 per thousand, P=0.025) among the PAH-exposed workers. The haplotype pairs GGGGTGC/AAACATT exhibited significantly higher CBMN frequency (12.05+/-7.40 per thousand) than did the GGGGTGC/GGGGTGC (7.51+/-6.19 per thousand, P=0.007) among the PAH-exposed group. In conclusion, it is suggested that the polymorphisms of ATM were associated with the CBMN frequencies among PAH-exposed workers.

[Association between polycyclic aromatic hydrocarbons exposure levels and nucleoplasmic bridge and nuclear bud frequencies in coke-oven workers].

OBJECTIVE: To seek new effect biomarkers as to evaluating the chromosomal damage in peripheral blood lymphocytes in coke-oven workers who were exposed to polycyclic aromatic hydrocarbons (PAHs). METHODS: One hundred and fifty-eight coke-oven workers and 69 controls were recruited in this study. Nucleoplasmic bridges and nuclear buds were counted as indicators of chromosomal damage in terms of cytokinesis-block micronucleus (CBMN) test. Occupational history, age, sex, smoking and alcohol using status of all subjects were collected by questionnaire. RESULTS: Frequencies of nucleoplasmic bridge in coke-oven workers were (9.41 +/- 3.73)% per hundred, and the frequencies of nuclear buds were (7.13 +/- 4.01)% per hundred, which were significantly higher (P < 0.01) than those of controls (1.88 +/- 1.49)% per hundred and (2.20 +/- 1.73)% per hundred respectively. The dose-effect relationships between nucleoplasmic bridges or nuclear buds and PAHs exposure levels were identified. Compared with male coke-oven workers, female workers had less nucleoplasmic bridges or nuclear buds. No effects of age, smoking and alcohol using were found on nucleoplasmic bridges or nuclear buds among coke-oven workers. CONCLUSION: Nucleoplasmic bridges and nuclear buds might be effect biomarkers in coke-oven workers.

Association of aryl hydrocarbon receptor gene polymorphisms and urinary 1-hydroxypyrene in polycyclic aromatic hydrocarbon-exposed workers.

Polycyclic aromatic hydrocarbons (PAH) in coke oven emissions could cause lung cancer in human. Individual's genotype of the metabolic enzymes and early biological changes were known to be associated with the susceptibility of cancer development. Knowledge of metabolic gene polymorphisms, which affect on the urinary 1-hydroxypyrene (1-OHP), could benefit us in understanding the interindividual difference in the mechanism of PAH-induced carcinogenesis. In this study, we investigated the association of aryl hydrocarbon receptor (AhR) gene polymorphisms and urinary 1-OHP. One hundred forty-seven workers exposed to PAH and 69 nonexposure workers were recruited. Seven tagging single nucleotide polymorphisms in AhR gene were selected by pariwise r(2) method and minor allele frequency cutoff of 0.05 from Chinese genotype data in HapMap project. These seven tagging single nucleotide polymorphisms were genotyped by PCR-based methods. Multivariate analysis of covariance revealed that the levels of 1-OHP in PAH-exposed workers carrying genotype CT were lower than workers carrying wild genotype TT at loci rs10250822 and rs2282885 of AhR gene (P = 0.032 and 0.044, respectively). In PAH-exposed workers, the urinary 1-OHP levels showed a linear correlation (P(trend) = 0.041) with the genotypes at locus rs2282885, especially in low and moderate exposure groups. In contrast, no significant association was found between urinary 1-OHP level and AhR genotypes among nonexposed workers. Our findings indicated that polymorphisms of AhR gene were associated with the level of 1-OHP among PAH-exposed workers, suggesting that AhR-mediated signaling might contribute to individual susceptibility to PAH exposure.

[Association between nucleotide excision repair gene polymorphisms and chromosomal damage in coke-oven workers].

OBJECTIVE: To investigate the association of polymorphisms of nucleotide excision repair genes and chromosomal damage in peripheral blood lymphocytes among coke-oven workers. METHODS: The genotypes of ERCC1 C19007T, ERCC2 C22541A, ERCC2 G23591A, ERCC2 A35931C, ERCC4 T30028C, ERCC5 G3507C and ERCC6 A3368G among 140 coke-oven workers and 66 non-coke-oven controls were determined by PCR-PFLP methods. Chromosomal damage was detected by cytokinesis-block micronucleus (CBMN) assay. RESULTS: Multivariate analysis of covariance revealed that in coke-oven workers, the ERCC1 19007 CC genotype exhibited significantly higher CBMN frequency [(1.05 +/- 0.68)%] than did the CT [(0.81 +/- 0.66)%] (P = 0.01) or TT [(0.66 +/- 0.37)%] (P = 0.05) or CT + TT genotypes [(0.75 +/- 0.63)%] (P = 0.004). For the ERCC6 A3368G polymorphism, AA genotype exhibited significantly higher CBMN frequency [(1.00 +/- 0.69)%] than did the AG [(0.67 +/- 0.42)%] (P = 0.05) or AG + GG genotypes [(0.66 +/- 0.41)%] (P = 0.02). Stratification analysis found the significant association between the two polymorphisms, ERCC1 C19007T and ERCC6 A3368G, and the CBMN frequencies were most pronounced in older workers. In addition, for the polymorphism of ERCC2 G23591A, GA carriers had significantly higher CBMN frequencies [(1.40 +/- 0.63)%] than those GG carriers [(0.98 +/- 0.59)%] (P = 0.01) in older workers. CONCLUSIONS: Our results suggested that polymorphisms of ERCC1 C19007T, ERCC6 A3368G and ERCC2 G23591A were associated with the CBMN frequencies in coke-oven workers.

[Association of XRCC1 polymorphisms and chromosomal damage levels in coke-oven workers].

OBJECTIVE: To investigate the association of XRCC1 polymorphisms and chromosomal damage levels in peripheral blood lymphocyte in coke-oven workers. METHODS: The study included 141 coke-oven workers who exposed to a high level of polycyclic aromahaplotpetic hydrocarbon and 66 non-exposed controls. Urinary 1-hydroxypyrene and chromosome damage in peripheral lymphocyte were measured. Four -tagging single nucleotide polymorphisms in XRCC1 gene, including C26304T, G27466A, G28152A and G36189A, were detected and the XRCC1 haplotypes were estimated by using an extension of Clark algorithm. The associations between haplotype pairs and micronuclei data were assessed by analysis of covariance in the exposed and non-exposed groups. RESULTS: The geometric means of urinary 1-hydroxypyrene levels in coke-oven workers and the controls were 12.0 and 0.7 micromol/mol Cr respectively (P < 0.01). The cytokinesis-block micronucleus cytokinesis-block micronucleus frequencies (number of micronucleus per 1 000 binucleated lymphocytes) was significantly higher in coke-oven workers (0.95 +/- 0.66)% than in the controls (0.40 +/- 0.36)%, P < 0.01. The haplotype CGGG was associated with the decreased frequencies of total micronucleus, and the haplotypes TGGG (P = 0.01) and CGAG (P < 0.05) were associated with the increased frequencies of total micronucleus in the multivariate analysis with adjustment for covariates among coke-oven workers. CONCLUSIONS: The genetic polymorphisms of XRCC1 gene could influence the chromosome damage levels in coke-oven workers.

[Association of metabolic and DNA repair enzyme gene polymorphisms and DNA damage in coke-oven workers].

OBJECTIVE: To investigate the association of polymorphisms of metabolic and DNA repair enzyme genes and DNA damage in peripheral blood lymphocytes in coke-oven workers. METHODS: One hundred and forty-four coke-oven workers and 50 controls were recruited in this study. Urinary 1-hydroxypyrene (1-OHP) levels were measured as the internal dose of polycyclic aromatic hydrocarbons exposure. DNA damage was detected by alkaline comet assay, and the value of 1.74 was used as the cut-off value to determine whether the individual's DNA damage was positive. The genotypes of CYP1A1, CYP2E1, GSTP1, NQO1, mEH and XRCC1 were determined by PCR-based methods. With adjustment for urinary 1-OHP, age, sex, multiple analysis of covariance was used to study the association between genotypes and the ln-transformed olive TM and multiple logistic regression was used to calculate the adjusted OR and the 95% CI for the risk of DNA damage. RESULTS: In 144 coke-oven workers, with adjustment for urinary 1-OHP, coking history and sex, the olive TM was significantly higher with XRCC1 280His allele than those with Arg allele (5.6 vs. 2.8, P < 0.01). The subjects with XRCC1 280His allele also have significantly higher risk for DNA damage than subjects with Arg allele (adjusted OR = 2.66, 95% CI = 1.00-7.14, P = 0.05) and the subjects with GSTP1 104Val allele have higher risk for DNA damage than subjects with Ile allele (adjusted OR = 1.90, 95% CI = 0.94-3.85, P = 0.07). CONCLUSION: XRCC1 and GSTP1 polymorphisms might influence the susceptibility of DNA damage in occupational PAH-exposed coke-oven workers.

The association of XRCC1 haplotypes and chromosomal damage levels in peripheral blood lymphocyte among coke-oven workers.

Theoretically, a haplotype has a higher level of heterozygosity than individual single nucleotide polymorphism (SNP) and the association study based on the haplotype may have an increased power for detecting disease associations compared with SNP-based analysis. In this study, we investigated the effects of four haplotype-tagging SNPs (htSNP) and the inferred haplotype pairs of the X-ray cross-complementing group 1 (XRCC1) gene on chromosome damage detected by the cytokinesis-block micronucleus assay. The study included 141 coke-oven workers with exposure to a high level of polycyclic aromatic hydrocarbons and 66 nonexposed controls. The frequencies of total MN and MNed cells were borderline associated with the Arg(194)Trp polymorphism (P = 0.053 and P = 0.050, respectively) but not associated with the Arg(280)His, Arg(399)Gln and Gln(632)Gln polymorphisms among coke-oven workers. Five haplotypes, including CGGG, TGGG, CAGG, CGAG, and CGGA, were inferred based on the four htSNPs of XRCC1 gene. The haplotype CGGG was associated with the decreased frequencies of total MN and MNed cells, and the haplotypes TGGG and CGAG were associated with the increased frequencies of total MN and MNed cells with adjustment for covariates among coke-oven workers. This study showed that the haplotypes derived from htSNPs in the XRCC1 gene were more likely than single SNPs to correlate with the polycyclic aromatic hydrocarbon-induced chromosome damage among coke-oven workers.

[Preliminary study on naphthalene-metabolites-albumin adduct as an exposure biomarker for coke oven workers].

OBJECTIVE: To study albumin adduct with naphthalene metabolites, namely 1,2-naphthoquinone (1,2-NPQ) and 1,4-naphthoquinone (1,4-NPQ), as a potential biomarker for intermediate/long-term exposure to polycyclic aromatic hydrocarbons (PAH) in coke oven workers. METHODS: Twenty-eight coke oven workers and 22 control workers were recruited from a cokery. Spot urine and venous blood samples were collected from the workers after four continuously working days and personal information was obtained by questionnaire. Plasma albumin adduct was detected with gas chromatography-mass spectrometry. RESULTS: Albumin adduct with 1,2- & 1,4-NPQ (1,2-NPQ and 1,4-NPQ), respectively, were detected in all coke oven workers and controls. Median plasma level of 1,2-NPQ-Alb in coke oven workers was significantly higher than that in controls (76.6 pmol/g vs. 44.9 pmol/g, P < 0.01). However, there was no significant difference in plasma median level of 1,4-NPQ-Alb between the two groups (48.6 pmol/g vs. 44.2 pmol/g, P > 0.05). Plasma level of 1,2-NPQ-Alb was significantly higher than that of 1,4-NPQ-Alb in coke oven workers. Urine levels of naphthalene, 1-naphthol, 2-naphthol and 1-pyrenol in coke oven workers correlated significantly with their plasma level of 1,2-NPQ-Alb (Pearson coefficient of correlation greater than 0.371, P < 0.01), but did not do significantly with 1,4-NPQ-Alb. CONCLUSION: Plasma level of 1,2-NPQ-Alb could effectively reflect their magnitude of personal internal dose of exposure to air PAH, so it could be used as a potential biomarker to evaluate their intermediate/long-term exposure to PAH in coke oven workers.

Effects of genetic polymorphisms of metabolic enzymes on cytokinesis-block micronucleus in peripheral blood lymphocyte among coke-oven workers.

Exploring the associations between genetic polymorphisms of metabolic enzymes and susceptibility to polycyclic aromatic hydrocarbon (PAH)-induced chromosomal damage is of great significance for understanding PAH carcinogenesis. Cytochrome P450, glutathione S-transferase, microsomal epoxide hydrolase, NAD(P)H:quinone oxidoreductase, and N-acetyltransferase are PAH-metabolizing enzymes. In this study, we genotyped for the polymorphisms of these genes and assessed their effects on cytokinesis-block micronucleus (CBMN) frequencies in peripheral blood lymphocytes among 141 coke-oven workers and 66 non-coke-oven worker controls. The geometric means of urinary 1-hydroxypyrene levels in coke-oven workers and the controls were 12.0 and 0.7 micromol/mol creatinine, respectively (P < 0.01). The CBMN frequency (number of micronuclei per 1,000 binucleated lymphocytes) was significantly higher in coke-oven workers (9.5 +/- 6.6 per thousand) than in the controls (4.0 +/- 3.6 per thousand; P < 0.01). Among the coke-oven workers, age was positively associated with CBMN frequency; the mEH His113 variant genotype exhibited significantly lower CBMN frequency (8.5 +/- 6.5 per thousand) than did the Tyr113/Tyr113 genotype (11.3 +/- 6.4 per thousand; P < 0.01); the low mEH activity phenotype exhibited a lower CBMN frequency (8.6 +/- 6.8 per thousand) than did the high mEH activity phenotype (13.2 +/- 6.7 per thousand; P = 0.01); the GSTP1 Val105/Val105 genotype exhibited a higher CBMN frequency (15.0 +/- 5.8 per thousand) than did the GSTP1 Ile105/Ile105 or Ile105/Val105 genotypes (9.3 +/- 6.5 per thousand; P < 0.01); the joint effect of high mEH activity phenotype and GSTM1 null genotype on CBMN frequencies was also found. Gene-environment interactions between occupational PAH exposure and polymorphisms of mEH and/or GSTM1 were also evident. These results indicate that the mEH, GSTP1, and GSTM1 polymorphisms may play a role in sensitivity or genetic susceptibility to the genotoxic effects of PAH exposure in the coke-oven workers.

[Effect of genetic polymorphisms of microsomal epoxide hydrolase on urinary 1-hydroxypyrene levels in coke oven workers].

OBJECTIVE: To investigate the associations of polymorphisms of metabolic enzyme genes with urinary 1-hydroxypyrene levels in coke oven workers. METHODS: One hundred and forty-eight workers from a coke oven plant and 69 controls without occupational PAHs exposure were selected in this study. Urinary 1-hydroxypyrene was detected by high performance liquid chromatography with florescence detector. The genotypes at I462V site in exon 7 of CYP1A1 gene, GSTM1, GSTT1, I105V site in GSTP1gene, Pst1 and Dra1 sites in CYP2E1 gene, P187S site in NQO1 gene, Kpn1, BamH1 and Taq1 sites in NAT2 gene, and H113Y, R139H sites in mEH gene were determined by PCR-based methods. Personal information including occupational exposure history, age, sex, smoking and drinking status was collected by the questionnaire. RESULTS: The level of urinary 1-hydroxypyrene in coke oven workers [(5.61 +/- 1.04) mol/mol Cr] was higher than that in control [(0.74 +/- 0.32) micro mol/mol Cr]. After adjusting external occupational exposure category and smoking, coke oven workers with variant homozygotes at H113Y site of mEH gene had significantly higher urinary 1-hydroxypyrene concentrations than those with heterozygotes, and wild homozygotes (6.41 +/- 1.09 vs. 6.24 +/- 1.08, and 4.62 +/- 0.95 micro mol/mol Cr, P < 0.05), and gene-gene interaction was found between CYP1A1 and mEH. CONCLUSION: Genetic polymorphism of mEH gene could be a susceptible biomarker in coke oven workers which was involved in the individual susceptibility on metabolism of PAHs.

[Relationship of polycyclic aromatic hydrocarbon exposure with peripheral blood lymphocyte DNA damage in coke oven workers].

OBJECTIVE: To investigate the relationship between lymphocyte DNA damage and polycyclic aromatic hydrocarbons (PAHs) exposure in coke oven workers. METHODS: Two hundred and thirty-five coke oven workers and 30 controls were selected in this study. Alkaline single-cell gel electrophoresis was used to evaluate the lymphocyte DNA damage, HPLC was employed to measure 1-hydroxypyrene levels in spot urine samples which were obtained at the end of a workweek (4 days of 8 hours/day) and personal information including occupational exposure, age, sex, smoking and drinking status was collected by the questionnaire. RESULTS: The lymphocyte DNA damage level expressed as olive moment in coke oven workers was significantly higher than that of controls [2.47 (0.22 approximately 46.68) vs 0.94 (0.42 approximately 4.21), P < 0.01], and correlation between urinary 1-hydroxypyrene concentrations and olive moment was found (Spearman Partial correlation coefficient = 0.22, P < 0.01) in coke oven workers. The 1.9 of olive moment value was used as the limit to determine whether the subject DNA damage was positive. The coke oven workers had significantly higher risk in DNA damage (adjusted OR = 5.38, 95% CI = 2.07 approximately 14.08) than did controls, and dose-response relationships were also found between external exposure (exposure category) or internal doses (urinary 1-hydroxypyrene) and DNA damage. CONCLUSION: There are dose-effect and dose-response relationships between PAHs exposure and lymphocyte DNA damage in coke oven workers.

[A study on the inherited susceptibility of chromosomal damage in peripheral blood lymphocytes among coke oven workers].

OBJECTIVE: To investigate the association between polymorphisms of metabolic enzyme genes and chromosomal damage risk in peripheral blood lymphocytes among coke oven workers. METHODS: One hundred and fourty-nine coke oven workers and 24 referents without occupational polycyclic aromatic hydrocarbons (PAH) exposure were recruited in this study. Urinary 1-hydroxypyrene levels were measured as the internal dose of PAH exposure. The 6 per 1 000 of micronucleus value was used as the cut-off value to determine whether the individual's chromosomal damage was positive. The genotypes of CYP1A1, GSTM1, GSTT1, GSTP1, CYP2E1, NQO1, NAT2 and mEH genes were determined by PCR-based methods. Multiple logistic regression was used to calculate the adjusted ORs and the 95% CI for the risk of chromosomal damage and to analyze the gene-gene interaction. RESULTS: In 173 subjects, after adjusting the occupational exposure, age, sex, smoking and drinking status, the subjects with GSTM1 null genotype have significantly higher risk for chromosomal damage than subjects with GSTM1 positive genotype (adjusted OR = 2.01, 95% CI = 1.03 -3.91). Compared with the wild homozygotes at P187S site of NQO1 gene, the variant homozygotes have significantly higher risk for chromosomal damage (adjusted OR = 3.18, 95% CI = 1.18 - 8.62). The subjects with variant allele at H113Y site of mEH gene have significantly lower risk for chromosomal damage (adjusted OR = 0.40, 95% CI = 0.19 - 0.88). No significant associations were found for other gene polymorphisms and chromosomal damage risk. In addition, the gene-gene interactions were also found among GSTM1, NQO1 gene P187S and mEH gene H113Y polymorphisms for the risk of chromosomal damage risk. CONCLUSION: Significant associations between genetic polymorphisms in GSTM1, NQO1 and mEH gene and risk for chromosomal damage were found among occupational PAH-exposed workers, which related to the mechanism of PAH carcinogenesis.

[Genetic damage in peripheral blood lymphocyte of coke oven workers].

OBJECTIVE: To investigate DNA and chromosome damage in peripheral blood lymphocyte of coke oven workers exposed to polycyclic aromatic hydrocarbons (PAHs). METHODS: One hundred and thirty-seven coke oven workers and 50 controls without occupational PAHs exposure were investigated. Comet assay and cytokinesis-block micronucleus (CBMN) detection were used to evaluate DNA and chromosomal damage levels in peripheral blood lymphocyte. Urinary 1-hydroxypyrene level was used to assess the personal internal PAHs exposure dose. Personal information including occupational history, age, sex, smoking and drinking status was collected by questionnaire. RESULTS: Urinary 1-hydroxypyrene level in coke oven workers [(5.76 +/- 1.04) micro mol/mol Cr] was significantly higher than that in controls [(0.70 +/- 0.32) micro mol/mol Cr]. The rate of CBMN and comet tail moment of lymphocyte in coke oven workers [8.0 per thousand (0.0 per thousand - 30.0 per thousand ) and 2.09 (0.31 - 75.41), respectively] were higher than those in controls [3.5 per thousand (0.0 per thousand - 13.0 per thousand ) and 1.05 (0.11 - 6.63), P < 0.05]. In controls, the comet moment in smokers was significantly higher than that in non-smokers [1.44 (0.23 - 6.63) vs 0.81 (0.11 - 3.47), P < 0.05]. According to the length of work, 137 coke oven workers were classified into 3 groups i.e. 0.5 yrs , 16.0 yrs and 22.0 yrs group, and the comet moments were 1.34 (0.31 - 37.84), 2.32 (0.49 - 52.97) and 3.20 (0.45 - 75.41) respectively after adjusting the age, sex, smoking, drinking and level of urinary 1-hydroxy-pyrene. There was a rising tendency along with the increase in length of work. CONCLUSION: Under present PAHs exposure levels, both comet assay and Cytokinesis-block micronucleus test could detect PAHs-induced genotoxicity in coke oven workers, and comet assay is more suitable to assess the cumulative damage effect on DNA.

Associations between XRCC1 and ERCC2 polymorphisms and DNA damage in peripheral blood lymphocyte among coke oven workers.

A wide variety of base damages and single-strand breaks formed by reactive oxygen species during metabolic activation of polycyclic aromatic hydrocarbons (PAHs) have been recognized to be involved in PAH carcinogenesis. In this study, alkaline comet assay was used to detect the DNA damage in peripheral blood lymphocytes among 143 coke-oven workers and 50 non-coke-oven workers, and the effects of genetic polymorphisms of XRCC1 and ERCC2 genes on DNA damage were evaluated. The olive tail moment was significantly higher in coke-oven workers than in non-coke-oven workers (2.6, 95% CI=2.1-3.3 versus 1.0, 95% CI=0.8-1.2, p<0.01), and significant correlation between ln-transformed urinary 1-OHP and ln-transformed olive tail moment was found in total population (n=193, Pearson's r=0.393, p<0.001) and in coke-oven workers (n=143, Pearson's r=0.224, p=0.007). The olive tail moment was significantly higher in coke-oven workers with GA genotype of G27466A polymorphism of XRCC1 than those with GG genotype (4.6, 95% CI=2.5-8.7 versus 2.4, 95% CI=1.9-2.9, p<0.01 with adjustment for covariates). No significant associations between C26304T, G28152A and G36189A polymorphisms of XRCC1 and G23591A and A35931C polymorphisms of ERCC2 and olive tail moment were found in both groups. The study showed that the alkaline comet assay is a suitable biomarker in the detection of DNA damage among coke-oven workers and it suggested that the A allele of G27466A polymorphism of XRCC1 may be associated with decreased DNA repair capacity toward PAH-induced base damage and strand breaks.

[A study on the relationship between urinary 1-hydroxypyrene level and early genetic effect among coke oven workers].

OBJECTIVE: To investigate the relationship between the urinary 1-hydroxypyrene level and cytokinesis-block micronucleus and the olive moment of comet assay in peripheral blood lymphocyte in coke oven workers. METHODS: One hundred and thirty-three workers from a coke plant and 28 referents without occupational PAH exposure were recruited in this study. Urinary level of 1-hydroxypyrene was measured by alkaline hydrolysis combined with high performance liquid chromatography as an internal exposure dose, and the DNA and chromosomal damage of peripheral blood lymphocyte were evaluated with comet assay and cytokinesis-block micronucleus method. Personal information including occupational history, age, sex, smoking and alcohol drinking, was collected by questionnaire. RESULTS: There existed a good correlationship between the urinary level of 1-hydroxypyrene and frequency of micronuclei per 1 000 binucleated cells or the olive moment of comet assay in the study subjects, after adjusting for sex, age, smoking and alcohol drinking (r > 0.25, P < 0.01). One hundred and sixty-one subjects were divided into three groups by their urine 1-hydroxypyrene level (expressed as 0.30 - 2.44, 2.45 - 7.09 and 7.10 - 33.10 micro mol/mol Cr), and the geometric means of their urinary levels of 1-hydroxypyrene were 1.14, 4.32 and 12.49 micro mol/mol Cr, respectively. After adjusting for age, sex, smoking and alcohol drinking by multiple nonparametric analysis of covariance, the median of olive moment of comet assay in the group of 7.10 - 33.10 micro mol/mol Cr was 3.67, significantly higher than that in the groups of 0.30 - 2.44 and 2.45 - 7.09; and the micronuclei frequencies in the groups of 2.45 - 7.09 and 7.10 - 33.10 micro mol/mol Cr were 8.00 per thousand and 7.50 per thousand, respectively, significantly higher than that in the group of 0.30 - 2.44 micro mol/mol Cr (6.00 per thousand ). CONCLUSIONS: The comet assay of peripheral blood lymphocyte was more suitable to detect the PAHs-induced early genotoxicity, than the cytokinesis-block micronucleus.