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GSTM1 polymorphism associated with the formation of acrylamide-mercapturic acids in acrylamide-exposed works
Abstracts / Toxicology Letters 196S (2010) S37–S351
the genotoxic effect on the occupationally exposure personnel to cancer chemotherapeutic agents has been studied. Blood samples from a total of 16 subjects (experimental group) who were nurses involved in the preparation, handling or administration of cancer chemotherapeutic agents were analyzed for DNA damage by using the single cell electrophoresis assay (comet assay). In parallel, blood samples from 16 nurses from the same hospital who were not exposed to chemotherapeutic agents were also analyzed and compared with the experimental group. The incidence of DNA single strand breaks (SSB) in peripheral mononuclear blood cells was evaluated by using the parameter of %DNA in the comet tail. Data were initially checked for normality, homoscedasticity and homogeneity of variance. An unpaired Studentˇıs t-test between the median values of the two groups revealed a statistically significant increase of SSB in the group involved in the preparation, handling or administration of cancer chemotherapeutic agents (P < 0.01). Different epidemiological health data of the subjects (e.g. age, smoking and dietary habits) were also evaluated and correlated with the observed DNA damage as possible confounding variables. Our data demonstrate clearly genotoxic effects related to occupational exposure to chemotherapeutics, indicating insufficient safety design and practices. They also suggest that the SSBs could be an appropriate biomarker for evaluating genotoxicity in these employees. The comet assay in peripheral blood could provide an easy tool of the Health and Safety Department in hospitals for the exposure monitoring. doi:10.1016/j.toxlet.2010.03.280
P104-025 GSTM1 polymorphism associated with the formation of acrylamide-mercapturic acids in acrylamide-exposed works K.Y. Wu 1 , N.Y.F. Huang 2 , M.L. Chen 2 , S.N. Uang 3 , S.H. Liou 4 , M.F. Chen 4 1
National Taiwan University, 2 National Yang-Ming University, Institute of Occupational Safety and Health, 4 National Health Research Institutes
3
Acrylamide (AA), an animal carcinogen and neurotoxicant, widely used in industry and present in tabcco smoke and hightemperature processed foods. Ubiquitous exposures to AA have been of great concerns. AA and its active metabolite glycidamide can be detoxified by glutathione transferase and further metabolized to form 3 mercapturic acids, abbreviated as AAMA, GAMA2, and GAMA3. The objective of this paper was to study the effects of the interactions between AA exposures and genetic polymorphisms of phase I and II metabolic enzymes on the urinary levels of the 3 MAs. Total 51 AA-exposed and 34 control workers were recruited. Personal samples, blood, and pre-shift and post-shift urine samples were collected. Airborne AA was analyzed by using an isotope-dilution GC/MS method. Urinary AAMA, GAMA2, and GAMA3 were analyzed with an isotope-dilution LC-MS/MS operated under MRM. The PCR-RFLP method was applied to analyze CYP2E1, GST, and mEH genetic polymorphisms. Chemical analysis revealed that workers were exposed to AA in the range from 0.006 to 0.051 mg/m3 with a mean at 0.023 mg/m3 . Statistical analysis demonstrates that AA-exposed workers excreted significantly higher levels of AAMA, GAMA2, and GAMA3 than the control group. Multiple linear regressions show that AA exposures and GSTM1 genotype were significantly associated with the formation of AAMA and GAMAs (GAMA2 + GAMA3). GSTM1 was also significantly associated with the ratios of GAMAs/AAMA (0.005–0.013). These results demonstrate that only a small proportion of AA absorbed is
S75
metabolized to glycidamide which can be detoxified by GSTM1 in humans. doi:10.1016/j.toxlet.2010.03.281
P104-026 Toxic effects of ethyl tertiary butyl ether exposure as modified by ALDH2 gene in mice R.S. Wang, K. Ohtani, M. Suda, Z. Weng Japan National Institute of Occupational Safety and Health, Japan Ethyl tertiary butyl ether (ETBE) is biomass energy and it has been used by mixing with gasoline in some countries in recent years. Previous studies showed that ETBE may cause damage to liver and kidneys at high concentrations in animals. The causative species is yet to be identified, but aldehydes produced during the metabolism of ETBE may be critical. These intermediates show a variety of toxic effects in body, and its detoxification is mainly dependent on aldehyde dehydrogenase 2 (ALDH2). However, approximately 40% East Asians lack the enzyme activity. We studied if there is difference in the toxic effects of ETBE using ALDH2 knockout and wild type mice. METHODS: ALDH2+/+ (KO mice) and C57BL/6 strain (WT mice) were exposed to ETBE at 0, 500, 1750 and 5000 ppm ETBE, 6 h/day and 5 days/week, for 13 weeks. Blood, liver and epididymides were sampled 20 h after the last exposure. RESULTS: Increase in the ratio of liver/body weight was only observed in 5000 ppm exposure of both WT and KO mice, and the mean of serum AST and ALT was not elevated in any exposure groups. On the other hand, the ratio of epididymides to body weight was decreased at 1750 and 5000 ppm ETBE exposure, but the atrophy was only observed in KO, but not WT mice. The percentage of motile sperm was lower in 5000 ppm group of WT mice, but it was decreased in all three exposure groups of KO mice. Similarly, the increase of static sperm was found from 500 ppm exposure in KO mice, but it was only detected at 5000 ppm in WT mice. These results indicated that ALDH2 genetic polymorphisms may modify the toxic effects of ETBE. We thank Ms. S. Watanabe for her assistance in the manipulation of the animals. doi:10.1016/j.toxlet.2010.03.282
P104-027 Formaldehyde occupational exposure: Genotoxic evaluation S. Costa 1 , S. Silva 1 , C. Costa 1 , P. Coelho 1 , C. Pina 1 , J. Gaspar 2 , A. Tavares 3 , J.P. Teixeira 1 National Institute of Health,Porto, Portugal, 2 Faculty of Medical Sciences UNL, Lisbon, Portugal, 3 Regional Health Administration, Lisbon and Tagus Valley Health Authority, Portugal
1
Given its economic importance and widespread use, formaldehyde (FA) is an important industrial compound to witch many people is exposed both environmentally and/or occupationally. Because of its sensitising properties, irritating effects and potential cancer hazard, FA is of great environmental health interest. The highest level of human exposure to this aldehyde occurs in occupational settings, namely in pathology and anatomy laboratories. In order to evaluate the potential health effects due to long-term occupational exposure to FA a group of pathology/anatomy workers was tested for a variety of biological endpoints: micronuclei (MN); sister chromatid exchange (SCE)- and comet assay (comet tail length, TL). In addition, the frequency of polymorphic genes of xenobiotic metabolising
the genotoxic effect on the occupationally exposure personnel to cancer chemotherapeutic agents has been studied. Blood samples from a total of 16 subjects (experimental group) who were nurses involved in the preparation, handling or administration of cancer chemotherapeutic agents were analyzed for DNA damage by using the single cell electrophoresis assay (comet assay). In parallel, blood samples from 16 nurses from the same hospital who were not exposed to chemotherapeutic agents were also analyzed and compared with the experimental group. The incidence of DNA single strand breaks (SSB) in peripheral mononuclear blood cells was evaluated by using the parameter of %DNA in the comet tail. Data were initially checked for normality, homoscedasticity and homogeneity of variance. An unpaired Studentˇıs t-test between the median values of the two groups revealed a statistically significant increase of SSB in the group involved in the preparation, handling or administration of cancer chemotherapeutic agents (P < 0.01). Different epidemiological health data of the subjects (e.g. age, smoking and dietary habits) were also evaluated and correlated with the observed DNA damage as possible confounding variables. Our data demonstrate clearly genotoxic effects related to occupational exposure to chemotherapeutics, indicating insufficient safety design and practices. They also suggest that the SSBs could be an appropriate biomarker for evaluating genotoxicity in these employees. The comet assay in peripheral blood could provide an easy tool of the Health and Safety Department in hospitals for the exposure monitoring. doi:10.1016/j.toxlet.2010.03.280
P104-025 GSTM1 polymorphism associated with the formation of acrylamide-mercapturic acids in acrylamide-exposed works K.Y. Wu 1 , N.Y.F. Huang 2 , M.L. Chen 2 , S.N. Uang 3 , S.H. Liou 4 , M.F. Chen 4 1
National Taiwan University, 2 National Yang-Ming University, Institute of Occupational Safety and Health, 4 National Health Research Institutes
3
Acrylamide (AA), an animal carcinogen and neurotoxicant, widely used in industry and present in tabcco smoke and hightemperature processed foods. Ubiquitous exposures to AA have been of great concerns. AA and its active metabolite glycidamide can be detoxified by glutathione transferase and further metabolized to form 3 mercapturic acids, abbreviated as AAMA, GAMA2, and GAMA3. The objective of this paper was to study the effects of the interactions between AA exposures and genetic polymorphisms of phase I and II metabolic enzymes on the urinary levels of the 3 MAs. Total 51 AA-exposed and 34 control workers were recruited. Personal samples, blood, and pre-shift and post-shift urine samples were collected. Airborne AA was analyzed by using an isotope-dilution GC/MS method. Urinary AAMA, GAMA2, and GAMA3 were analyzed with an isotope-dilution LC-MS/MS operated under MRM. The PCR-RFLP method was applied to analyze CYP2E1, GST, and mEH genetic polymorphisms. Chemical analysis revealed that workers were exposed to AA in the range from 0.006 to 0.051 mg/m3 with a mean at 0.023 mg/m3 . Statistical analysis demonstrates that AA-exposed workers excreted significantly higher levels of AAMA, GAMA2, and GAMA3 than the control group. Multiple linear regressions show that AA exposures and GSTM1 genotype were significantly associated with the formation of AAMA and GAMAs (GAMA2 + GAMA3). GSTM1 was also significantly associated with the ratios of GAMAs/AAMA (0.005–0.013). These results demonstrate that only a small proportion of AA absorbed is
S75
metabolized to glycidamide which can be detoxified by GSTM1 in humans. doi:10.1016/j.toxlet.2010.03.281
P104-026 Toxic effects of ethyl tertiary butyl ether exposure as modified by ALDH2 gene in mice R.S. Wang, K. Ohtani, M. Suda, Z. Weng Japan National Institute of Occupational Safety and Health, Japan Ethyl tertiary butyl ether (ETBE) is biomass energy and it has been used by mixing with gasoline in some countries in recent years. Previous studies showed that ETBE may cause damage to liver and kidneys at high concentrations in animals. The causative species is yet to be identified, but aldehydes produced during the metabolism of ETBE may be critical. These intermediates show a variety of toxic effects in body, and its detoxification is mainly dependent on aldehyde dehydrogenase 2 (ALDH2). However, approximately 40% East Asians lack the enzyme activity. We studied if there is difference in the toxic effects of ETBE using ALDH2 knockout and wild type mice. METHODS: ALDH2+/+ (KO mice) and C57BL/6 strain (WT mice) were exposed to ETBE at 0, 500, 1750 and 5000 ppm ETBE, 6 h/day and 5 days/week, for 13 weeks. Blood, liver and epididymides were sampled 20 h after the last exposure. RESULTS: Increase in the ratio of liver/body weight was only observed in 5000 ppm exposure of both WT and KO mice, and the mean of serum AST and ALT was not elevated in any exposure groups. On the other hand, the ratio of epididymides to body weight was decreased at 1750 and 5000 ppm ETBE exposure, but the atrophy was only observed in KO, but not WT mice. The percentage of motile sperm was lower in 5000 ppm group of WT mice, but it was decreased in all three exposure groups of KO mice. Similarly, the increase of static sperm was found from 500 ppm exposure in KO mice, but it was only detected at 5000 ppm in WT mice. These results indicated that ALDH2 genetic polymorphisms may modify the toxic effects of ETBE. We thank Ms. S. Watanabe for her assistance in the manipulation of the animals. doi:10.1016/j.toxlet.2010.03.282
P104-027 Formaldehyde occupational exposure: Genotoxic evaluation S. Costa 1 , S. Silva 1 , C. Costa 1 , P. Coelho 1 , C. Pina 1 , J. Gaspar 2 , A. Tavares 3 , J.P. Teixeira 1 National Institute of Health,Porto, Portugal, 2 Faculty of Medical Sciences UNL, Lisbon, Portugal, 3 Regional Health Administration, Lisbon and Tagus Valley Health Authority, Portugal
1
Given its economic importance and widespread use, formaldehyde (FA) is an important industrial compound to witch many people is exposed both environmentally and/or occupationally. Because of its sensitising properties, irritating effects and potential cancer hazard, FA is of great environmental health interest. The highest level of human exposure to this aldehyde occurs in occupational settings, namely in pathology and anatomy laboratories. In order to evaluate the potential health effects due to long-term occupational exposure to FA a group of pathology/anatomy workers was tested for a variety of biological endpoints: micronuclei (MN); sister chromatid exchange (SCE)- and comet assay (comet tail length, TL). In addition, the frequency of polymorphic genes of xenobiotic metabolising