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Jafari Roshan S, Mansoori Y, Hosseini SR, Sabour D, Daraei A. Genetic variations in ATM and H2AX loci contribute to risk of hematological abnormalities in individuals exposed to BTEX chemicals. J Clin Lab Anal 2022; 36:e24321. [PMID: 35235704 PMCID: PMC8993635 DOI: 10.1002/jcla.24321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Revised: 02/17/2022] [Accepted: 02/19/2022] [Indexed: 11/20/2022] Open
Abstract
Background Loci controlling DNA double‐strand breaks (DSBs) repair play an important role in defending against the harmful health effects of benzene, toluene, ethylbenzene, and xylene (BTEX), but their gene variants may alter their repair capacity. The aim of the current study was to determine the relationship of functional polymorphisms ATM‐rs228589 A>T, WRN‐rs1800392 G>T and H2AX‐rs7759 A>G in DBS repair loci with the abnormal hematological indices in workers who exposed to BTEXs. Methods We included 141 cases with one or more abnormal hematological parameters, who had been occupationally exposed to BTEX chemicals and 152 controls with a similar exposure condition but without any abnormal hematological parameters. Atmospheric concentrations of BTEXs were measured and whole blood samples were taken from the participants to determine hematologic parameters and SNP genotyping. Results Results showed that T allele of ATM‐rs228589 and G allele of H2AX‐rs7759 had a higher frequency in cases than controls (p = 0.012 and p = 0.001, respectively). Also, AT and TT genotypes of ATM‐rs228589 and AG and GG genotypes of H2AX‐rs7759 were higher in cases compared to controls. The AT and TT genotypes of ATM‐rs228589 have significant associations with a risk of hematological abnormalities in the codominant (AT vs. AA, p = 0.018), dominant (AT + TT vs. AA, p = 0.010) and overdominant (AT vs. AA + TT, p = 0.037) models. The GG and AG genotypes of H2AX‐rs7759 were in relation with increased risk of abnormal hematological indices under codominant (GA vs. AA, p = 0.009 & GG vs. AA, p = 0.005), dominant (AG + GG vs. AA, p = 0.001), and recessive (GG vs. AA + AG, p = 0.025) models. Conclusions These observations may help to understand the mechanisms of BTEX hematotoxicity and identify useful biomarkers of risk assessment for workers exposed to BTEX.
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Affiliation(s)
- Samaneh Jafari Roshan
- Student Research Committee, Babol University of Medical Sciences, Babol, Iran.,Department of Medical Genetics, School of Medicine, Babol University of Medical Sciences, Babol, Iran
| | - Yaser Mansoori
- Noncommunicable Diseases Research Center, Fasa University of Medical Sciences, Fasa, Iran
| | - Seyed Reza Hosseini
- Social Determinants of Health Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran
| | - Davood Sabour
- Department of Medical Genetics, School of Medicine, Babol University of Medical Sciences, Babol, Iran
| | - Abdolreza Daraei
- Cellular and Molecular Biology Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran
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Luo H, Zhai L, Qiu W, Liang H, Yu L, Li Y, Xiong M, Guo J, Tang H. p16 loss facilitate hydroquinone-induced malignant transformation of TK6 cells through promoting cell proliferation and accelerating the cell cycle progression. ENVIRONMENTAL TOXICOLOGY 2021; 36:1591-1599. [PMID: 33932074 DOI: 10.1002/tox.23155] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 04/17/2021] [Indexed: 06/12/2023]
Abstract
The p16INK4A is a multifunction gene that includes regulation of the cell cycle, apoptosis, senescence and tumor development. However, the effects of p16 in hydroquinone-induced malignant transformation of TK6 cells remain unclear. The present study aimed to explore whether p16 loss facilitate malignant transformation in TK6 cells. The results demonstrated that p16/Rb signal pathway was suppressed in hydroquinone-induced malignant transformation of TK6 cells. We further confirmed that p16 loss stimulated cell proliferation, and accelerated cell cycle progression in vitro and in vivo. The immunoblotting analysis indicated that p16 regulated cell cycle progression via Rb and p53. Therefore, we conclude that p16 is involved in HQ-induced malignant transformation associated with suppressing Rb and p53 which resulting in accelerating the cell cycle progression.
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Affiliation(s)
- Hao Luo
- Department of Environmental and Occupational Health, Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, China
| | - Lu Zhai
- Department of Environmental and Occupational Health, Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, China
| | - Weifeng Qiu
- Department of Environmental and Occupational Health, Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, China
| | - Hairong Liang
- Department of Environmental and Occupational Health, Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, China
| | - Lei Yu
- Department of Environmental and Occupational Health, Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, China
| | - Yuan Li
- Department of Environmental and Occupational Health, Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, China
| | - Mengyun Xiong
- Department of Environmental and Occupational Health, Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, China
| | - Jiaying Guo
- Department of Environmental and Occupational Health, Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, China
| | - Huanwen Tang
- Department of Environmental and Occupational Health, Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, China
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Gagné JP, Lachapelle S, Garand C, Tsofack SP, Coulombe Y, Caron MC, Poirier GG, Masson JY, Lebel M. Different non-synonymous polymorphisms modulate the interaction of the WRN protein to its protein partners and its enzymatic activities. Oncotarget 2018; 7:85680-85696. [PMID: 27863399 PMCID: PMC5349866 DOI: 10.18632/oncotarget.13341] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Accepted: 09/27/2016] [Indexed: 12/25/2022] Open
Abstract
Werner syndrome (WS) is characterized by the premature onset of several age-associated pathologies including cancer. The protein defective in WS patients (WRN) is a helicase/exonuclease involved in DNA replication and repair. Here, we present the results of a large-scale proteome analysis that has been undertaken to determine protein partners of different polymorphic WRN proteins found with relatively high prevalence in the human population. We expressed different fluorescently tagged-WRN (eYFP-WRN) variants in human 293 embryonic kidney cells (HEK293) and used a combination of affinity-purification and mass spectrometry to identify different compositions of WRN-associated protein complexes. We found that a WRN variant containing a phenylalanine residue at position 1074 and an arginine at position 1367 (eYFP-WRN(F-R)) possesses more affinity for DNA-PKc, KU86, KU70, and PARP1 than a variant containing a leucine at position 1074 and a cysteine at position 1367 (eYFP-WRN(L-C)). Such results were confirmed in a WRN-deficient background using WS fibroblasts. Interestingly, the exonuclase activity of WRN recovered from immunoprecipitated eYFP-WRN(L-C) variant was lower than the eYFP-WRN(F-R) in WS cells. Finally, HEK293 cells and WS fibroblasts overexpressing the eYFP-WRN(F-R) variant were more resistant to the benzene metabolite hydroquinone than cells expressing the eYFP-WRN(L-C) variant. These results indicate that the protein-protein interaction landscape of WRN is subject to modulation by polymorphic amino acids, a characteristic associated with distinctive cell survival outcome.
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Affiliation(s)
- Jean-Philippe Gagné
- Centre de Recherche du CHU de Québec, Pavillon CHUL Université Laval, Faculté de Médecine, Québec, Canada
| | - Sophie Lachapelle
- Centre de Recherche sur le Cancer de l'Université Laval, Hôpital Hôtel-Dieu de Québec, Québec, Québec, Canada
| | - Chantal Garand
- Centre de Recherche du CHU de Québec, Pavillon CHUL Université Laval, Faculté de Médecine, Québec, Canada
| | - Serges P Tsofack
- Centre de Recherche du CHU de Québec, Pavillon CHUL Université Laval, Faculté de Médecine, Québec, Canada
| | - Yan Coulombe
- Centre de Recherche sur le Cancer de l'Université Laval, Hôpital Hôtel-Dieu de Québec, Québec, Québec, Canada
| | - Marie-Christine Caron
- Centre de Recherche sur le Cancer de l'Université Laval, Hôpital Hôtel-Dieu de Québec, Québec, Québec, Canada
| | - Guy G Poirier
- Centre de Recherche du CHU de Québec, Pavillon CHUL Université Laval, Faculté de Médecine, Québec, Canada
| | - Jean-Yves Masson
- Centre de Recherche sur le Cancer de l'Université Laval, Hôpital Hôtel-Dieu de Québec, Québec, Québec, Canada
| | - Michel Lebel
- Centre de Recherche du CHU de Québec, Pavillon CHUL Université Laval, Faculté de Médecine, Québec, Canada
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Hydroquinone-induced malignant transformation of TK6 cells by facilitating SIRT1-mediated p53 degradation and up-regulating KRAS. Toxicol Lett 2016; 259:133-142. [DOI: 10.1016/j.toxlet.2016.08.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2016] [Revised: 07/27/2016] [Accepted: 08/07/2016] [Indexed: 12/18/2022]
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5
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Li Z, Wang C, Zhu J, Bai Y, Wang W, Zhou Y, Zhang S, Liu X, Zhou S, Huang W, Bi Y, Wang H. The possible role of liver kinase B1 in hydroquinone-induced toxicity of murine fetal liver and bone marrow hematopoietic stem cells. ENVIRONMENTAL TOXICOLOGY 2016; 31:830-841. [PMID: 25534963 DOI: 10.1002/tox.22094] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Revised: 12/02/2014] [Accepted: 12/07/2014] [Indexed: 06/04/2023]
Abstract
Epidemiological studies suggest that the increasing incidence of childhood leukemia may be due to maternal exposure to benzene, which is a known human carcinogen; however, the mechanisms involved remain unknown. Liver Kinase B1 (LKB1) acts as a regulator of cellular energy metabolism and functions to regulate hematopoietic stem cell (HSC) homeostasis. We hypothesize that LKB1 contributes to the deregulation of fetal or bone hematopoiesis caused by the benzene metabolite hydroquinone (HQ). To evaluate this hypothesis, we compared the effects of HQ on murine fetal liver hematopoietic stem cells (FL-HSCs) and bone marrow hematopoietic stem cells (BM-HSCs). FL-HSCs and BM-HSCs were isolated and enriched by a magnetic cell sorting system and exposed to various concentrations of HQ (0, 1.25, 2.5, 5, 10, 20, and 40 μM) for 24 h. We found that the inhibition of differentiation and growth, as well as the apoptosis rate of FL-HSCs, induced by HQ were consistent with the changes in BM-HSCs. Furthermore, G1 cell cycle arrest was observed in BM-HSCs and FL-HSCs in response to HQ. Importantly, FL-HSCs were more sensitive than BM-HSCs after exposure to HQ. The highest induction of LKB1 and adenosine monophosphate-activated protein kinase (AMPK) was observed with a much lower concentration of HQ in FL-HSCs than in BM-HSCs. LKB1 may play a critical role in apoptosis and cell cycle arrest of HQ-treated HSCs. This research has developed innovative ideas concerning benzene-induced hematopoietic toxicity or embryotoxicity, which can provide a new experimental evidence for preventing childhood leukemia. © 2014 Wiley Periodicals, Inc. Environ Toxicol 31: 830-841, 2016.
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Affiliation(s)
- Zhen Li
- Department of Occupational and Environmental Health, School of Public Health, Wuhan University, Wuhan, Hubei, People's Republic of China
- Hubei Key Laboratory of Allergy and Immune-Related Diseases, Wuhan, Hubei, People's Republic of China
- Hubei Biomass-Resource Chemistry and Environmental Biotechnology Key Laboratory, Wuhan University, Wuhan, Hubei, People's Republic of China
| | - Chunhong Wang
- Department of Occupational and Environmental Health, School of Public Health, Wuhan University, Wuhan, Hubei, People's Republic of China
- Hubei Key Laboratory of Allergy and Immune-Related Diseases, Wuhan, Hubei, People's Republic of China
- Hubei Biomass-Resource Chemistry and Environmental Biotechnology Key Laboratory, Wuhan University, Wuhan, Hubei, People's Republic of China
| | - Jie Zhu
- Department of Occupational and Environmental Health, School of Public Health, Wuhan University, Wuhan, Hubei, People's Republic of China
- Hubei Key Laboratory of Allergy and Immune-Related Diseases, Wuhan, Hubei, People's Republic of China
- Hubei Biomass-Resource Chemistry and Environmental Biotechnology Key Laboratory, Wuhan University, Wuhan, Hubei, People's Republic of China
| | - YuE Bai
- Department of Occupational and Environmental Health, School of Public Health, Wuhan University, Wuhan, Hubei, People's Republic of China
- Hubei Key Laboratory of Allergy and Immune-Related Diseases, Wuhan, Hubei, People's Republic of China
- Hubei Biomass-Resource Chemistry and Environmental Biotechnology Key Laboratory, Wuhan University, Wuhan, Hubei, People's Republic of China
| | - Wei Wang
- Department of Occupational and Environmental Health, School of Public Health, Wuhan University, Wuhan, Hubei, People's Republic of China
- Hubei Key Laboratory of Allergy and Immune-Related Diseases, Wuhan, Hubei, People's Republic of China
- Hubei Biomass-Resource Chemistry and Environmental Biotechnology Key Laboratory, Wuhan University, Wuhan, Hubei, People's Republic of China
| | - Yanfeng Zhou
- Department of Occupational and Environmental Health, School of Public Health, Wuhan University, Wuhan, Hubei, People's Republic of China
- Hubei Key Laboratory of Allergy and Immune-Related Diseases, Wuhan, Hubei, People's Republic of China
- Hubei Biomass-Resource Chemistry and Environmental Biotechnology Key Laboratory, Wuhan University, Wuhan, Hubei, People's Republic of China
| | - Shaozun Zhang
- Department of Occupational and Environmental Health, School of Public Health, Wuhan University, Wuhan, Hubei, People's Republic of China
- Hubei Key Laboratory of Allergy and Immune-Related Diseases, Wuhan, Hubei, People's Republic of China
- Hubei Biomass-Resource Chemistry and Environmental Biotechnology Key Laboratory, Wuhan University, Wuhan, Hubei, People's Republic of China
| | - Xiangxiang Liu
- Department of Occupational and Environmental Health, School of Public Health, Wuhan University, Wuhan, Hubei, People's Republic of China
- Hubei Key Laboratory of Allergy and Immune-Related Diseases, Wuhan, Hubei, People's Republic of China
- Hubei Biomass-Resource Chemistry and Environmental Biotechnology Key Laboratory, Wuhan University, Wuhan, Hubei, People's Republic of China
| | - Sheng Zhou
- Department of Occupational and Environmental Health, School of Public Health, Wuhan University, Wuhan, Hubei, People's Republic of China
- Hubei Key Laboratory of Allergy and Immune-Related Diseases, Wuhan, Hubei, People's Republic of China
- Hubei Biomass-Resource Chemistry and Environmental Biotechnology Key Laboratory, Wuhan University, Wuhan, Hubei, People's Republic of China
| | - Wenting Huang
- Department of Occupational and Environmental Health, School of Public Health, Wuhan University, Wuhan, Hubei, People's Republic of China
- Hubei Key Laboratory of Allergy and Immune-Related Diseases, Wuhan, Hubei, People's Republic of China
- Hubei Biomass-Resource Chemistry and Environmental Biotechnology Key Laboratory, Wuhan University, Wuhan, Hubei, People's Republic of China
| | - Yongyi Bi
- Department of Occupational and Environmental Health, School of Public Health, Wuhan University, Wuhan, Hubei, People's Republic of China
- Hubei Key Laboratory of Allergy and Immune-Related Diseases, Wuhan, Hubei, People's Republic of China
- Hubei Biomass-Resource Chemistry and Environmental Biotechnology Key Laboratory, Wuhan University, Wuhan, Hubei, People's Republic of China
| | - Hong Wang
- Department of Occupational and Environmental Health, School of Public Health, Wuhan University, Wuhan, Hubei, People's Republic of China
- Hubei Key Laboratory of Allergy and Immune-Related Diseases, Wuhan, Hubei, People's Republic of China
- Hubei Biomass-Resource Chemistry and Environmental Biotechnology Key Laboratory, Wuhan University, Wuhan, Hubei, People's Republic of China
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Shen H, McHale CM, Haider SI, Jung C, Zhang S, Smith MT, Zhang L. Identification of Genes That Modulate Susceptibility to Formaldehyde and Imatinib by Functional Genomic Screening in Human Haploid KBM7 Cells. Toxicol Sci 2016; 151:10-22. [PMID: 27008852 DOI: 10.1093/toxsci/kfw032] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Though current functional genomic screening systems are useful for investigating human susceptibility to chemical toxicity, they have limitations. Well-established, high-throughput yeast mutant screens identify only evolutionarily conserved processes. RNA interference can be applied in human cells but is limited by incomplete gene knockout and off-target effects. Human haploid cell screening is advantageous as it requires knockdown of only a single copy of each gene. A human haploid cell mutant library (KBM7-Mu), derived from a chronic myeloid leukemia (CML) patient, was recently developed and has been used to identify genes that modulate sensitivity to infectious agents and pharmaceutical drugs. Here, we sought to improve the KBM7-Mu screening process to enable efficient screening of environmental chemicals. We developed a semi-solid medium based screening approach that cultures individual mutant colonies from chemically resistant cells, faster (by 2-3 weeks) and with less labor than the original liquid medium-based approach. As proof of principle, we identified genetic mutants that confer resistance to the carcinogen formaldehyde (FA, 12 genes, 18 hits) and the CML chemotherapeutic agent imatinib (6 genes, 13 hits). Validation experiments conducted on KBM7 mutants lacking each of the 18 genes confirmed resistance of 6 FA mutants (CTC1, FCRLA, GOT1, LPR5, M1AP, and MAP2K5) and 1 imatinib-resistant mutant (LYRM9). Despite the improvements to the method, it remains technically challenging to limit false positive findings. Nonetheless, our findings demonstrate the broad applicability of this optimized haploid approach to screen toxic chemicals to identify novel susceptibility genes and gain insight into potential mechanisms of toxicity.
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Affiliation(s)
- Hua Shen
- Superfund Research Program, School of Public Health, University of California, Berkeley, California 94720
| | - Cliona M McHale
- Superfund Research Program, School of Public Health, University of California, Berkeley, California 94720
| | - Syed I Haider
- Superfund Research Program, School of Public Health, University of California, Berkeley, California 94720
| | - Cham Jung
- Superfund Research Program, School of Public Health, University of California, Berkeley, California 94720
| | - Susie Zhang
- Superfund Research Program, School of Public Health, University of California, Berkeley, California 94720
| | - Martyn T Smith
- Superfund Research Program, School of Public Health, University of California, Berkeley, California 94720
| | - Luoping Zhang
- Superfund Research Program, School of Public Health, University of California, Berkeley, California 94720
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7
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Shen H, McHale CM, Smith MT, Zhang L. Functional genomic screening approaches in mechanistic toxicology and potential future applications of CRISPR-Cas9. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2015; 764:31-42. [PMID: 26041264 DOI: 10.1016/j.mrrev.2015.01.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Revised: 01/14/2015] [Accepted: 01/16/2015] [Indexed: 01/25/2023]
Abstract
Characterizing variability in the extent and nature of responses to environmental exposures is a critical aspect of human health risk assessment. Chemical toxicants act by many different mechanisms, however, and the genes involved in adverse outcome pathways (AOPs) and AOP networks are not yet characterized. Functional genomic approaches can reveal both toxicity pathways and susceptibility genes, through knockdown or knockout of all non-essential genes in a cell of interest, and identification of genes associated with a toxicity phenotype following toxicant exposure. Screening approaches in yeast and human near-haploid leukemic KBM7 cells have identified roles for genes and pathways involved in response to many toxicants but are limited by partial homology among yeast and human genes and limited relevance to normal diploid cells. RNA interference (RNAi) suppresses mRNA expression level but is limited by off-target effects (OTEs) and incomplete knockdown. The recently developed gene editing approach called clustered regularly interspaced short palindrome repeats-associated nuclease (CRISPR)-Cas9, can precisely knock-out most regions of the genome at the DNA level with fewer OTEs than RNAi, in multiple human cell types, thus overcoming the limitations of the other approaches. It has been used to identify genes involved in the response to chemical and microbial toxicants in several human cell types and could readily be extended to the systematic screening of large numbers of environmental chemicals. CRISPR-Cas9 can also repress and activate gene expression, including that of non-coding RNA, with near-saturation, thus offering the potential to more fully characterize AOPs and AOP networks. Finally, CRISPR-Cas9 can generate complex animal models in which to conduct preclinical toxicity testing at the level of individual genotypes or haplotypes. Therefore, CRISPR-Cas9 is a powerful and flexible functional genomic screening approach that can be harnessed to provide unprecedented mechanistic insight in the field of modern toxicology.
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Affiliation(s)
- Hua Shen
- Superfund Research Program, Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, CA 94720, USA
| | - Cliona M McHale
- Superfund Research Program, Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, CA 94720, USA
| | - Martyn T Smith
- Superfund Research Program, Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, CA 94720, USA
| | - Luoping Zhang
- Superfund Research Program, Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, CA 94720, USA.
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8
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Zhang L, McHale CM, Greene N, Snyder RD, Rich IN, Aardema MJ, Roy S, Pfuhler S, Venkatactahalam S. Emerging approaches in predictive toxicology. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2014; 55:679-688. [PMID: 25044351 PMCID: PMC4749138 DOI: 10.1002/em.21885] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Accepted: 06/19/2014] [Indexed: 05/29/2023]
Abstract
Predictive toxicology plays an important role in the assessment of toxicity of chemicals and the drug development process. While there are several well-established in vitro and in vivo assays that are suitable for predictive toxicology, recent advances in high-throughput analytical technologies and model systems are expected to have a major impact on the field of predictive toxicology. This commentary provides an overview of the state of the current science and a brief discussion on future perspectives for the field of predictive toxicology for human toxicity. Computational models for predictive toxicology, needs for further refinement and obstacles to expand computational models to include additional classes of chemical compounds are highlighted. Functional and comparative genomics approaches in predictive toxicology are discussed with an emphasis on successful utilization of recently developed model systems for high-throughput analysis. The advantages of three-dimensional model systems and stem cells and their use in predictive toxicology testing are also described.
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Affiliation(s)
- Luoping Zhang
- Genes and Environment Laboratory, Division of Environmental Health and Sciences, School of Public Health, University of California, Berkeley, California
| | - Cliona M. McHale
- Genes and Environment Laboratory, Division of Environmental Health and Sciences, School of Public Health, University of California, Berkeley, California
| | - Nigel Greene
- Compound Safety Prediction, Worldwide Medicinal Chemistry, Pfizer World-wide R&D, Groton, Connecticut
| | | | | | - Marilyn J. Aardema
- Marilyn Aardema Consulting, LLC, Fairfield Ohio
- Toxicology Division, BioReliance Corporation, Rockville, Maryland
| | - Shambhu Roy
- Toxicology Division, BioReliance Corporation, Rockville, Maryland
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9
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Garige M, Sharma S. Cellular deficiency of Werner syndrome protein or RECQ1 promotes genotoxic potential of hydroquinone and benzo[a]pyrene exposure. Int J Toxicol 2014; 33:373-81. [PMID: 25228686 DOI: 10.1177/1091581814547422] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The 5 known RecQ helicases in humans (RECQ1, BLM, WRN, RECQL4, and RECQ5) have demonstrated roles in diverse genome maintenance mechanisms but their functions in safeguarding the genome from environmental toxicants are poorly understood. Here, we have evaluated a potential role of WRN (mutated in Werner syndrome) and RECQ1 (the most abundant homolog of WRN) in hydroquinone (HQ)- and benzo[a]pyrene (BaP)-induced genotoxicity. Silencing of WRN or RECQ1 expression in HeLa cells increased their sensitivity to HQ and BaP but elicited distinct DNA damage response. The RECQ1-depleted cells exhibited increased replication protein A phosphorylation, Chk1 activation, and DNA double-strand breaks (DSBs) as compared to control or WRN-depleted cells following exposure to BaP treatment. The BaP-induced DSBs in RECQ1-depleted cells were dependent on DNA-dependent protein kinase activity. Notably, loss of WRN in RECQ1-depleted cells ameliorated BaP toxicity. Collectively, our results provide first indication of nonredundant participation of WRN and RECQ1 in protection from the potentially carcinogenic effects of BaP and HQ.
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Affiliation(s)
- Mamatha Garige
- Department of Biochemistry and Molecular Biology, College of Medicine, Howard University, NW, Washington, DC, USA
| | - Sudha Sharma
- Department of Biochemistry and Molecular Biology, College of Medicine, Howard University, NW, Washington, DC, USA
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10
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McHale CM, Smith MT, Zhang L. Application of toxicogenomic profiling to evaluate effects of benzene and formaldehyde: from yeast to human. Ann N Y Acad Sci 2014; 1310:74-83. [PMID: 24571325 DOI: 10.1111/nyas.12382] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Genetic variation underlies a significant proportion of the individual variation in human susceptibility to toxicants. The primary current approaches to identify gene-environment (GxE) associations, genome-wide association studies and candidate gene association studies, require large exposed and control populations and an understanding of toxicity genes and pathways, respectively. This limits their application in the study of GxE associations for the leukemogens benzene and formaldehyde, whose toxicity has long been a focus of our research. As an alternative approach, our published work has applied innovative in vitro functional genomics testing systems, including unbiased functional screening assays in yeast and a near-haploid human bone marrow cell line. Through comparative genomic and computational analyses of the resulting data, human genes and pathways that may modulate susceptibility to benzene and formaldehyde were identified, and the roles of several genes in mammalian cell models were validated. In populations occupationally exposed to low levels of benzene, we applied peripheral blood mononuclear cell transcriptomics and chromosome-wide aneuploidy studies in lymphocytes. In this review, we describe our comprehensive toxicogenomic approach and the potential mechanisms of toxicity and susceptibility genes identified for benzene and formaldehyde, as well as related studies conducted by other researchers.
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Affiliation(s)
- Cliona M McHale
- Genes and Environment Laboratory, Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, California
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11
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Abstract
Patients with some progeroid syndromes, such as Werner syndrome, exhibit atherosclerotic cardiovascular disease (CVD) at a young age as a manifestation of premature aging. Recent studies have revealed that most progeroid syndromes are caused by genetic defects in specific molecules involved in the DNA damage response, a cornerstone of genome stability. Ionizing radiation is one of the most potent genotoxic stimuli and causes various kinds of DNA damage. Further, there is increasing evidence that therapeutic radiation treatments can cause cardiovascular complications. Here, we describe the DNA damage and subsequent response, review recent advances in the understanding of the molecular basis of progeroid syndromes (especially those syndromes that involve CVD), review the pathological and epidemiological analysis of radiation-induced CVD, and discuss the possible role of DNA damage and the DNA damage response in the pathogenesis of atherosclerotic CVD.
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Affiliation(s)
- Takafumi Ishida
- Department of Cardiovascular Medicine, Graduate School of Biomedical and Health Sciences, Hiroshima University
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12
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Genotoxicity of hydroquinone in A549 cells. Cell Biol Toxicol 2013; 29:213-27. [DOI: 10.1007/s10565-013-9247-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Accepted: 05/20/2013] [Indexed: 11/25/2022]
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McHale CM, Zhang L, Smith MT. Current understanding of the mechanism of benzene-induced leukemia in humans: implications for risk assessment. Carcinogenesis 2012; 33:240-52. [PMID: 22166497 PMCID: PMC3271273 DOI: 10.1093/carcin/bgr297] [Citation(s) in RCA: 205] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2011] [Revised: 11/21/2011] [Accepted: 12/07/2011] [Indexed: 01/01/2023] Open
Abstract
Benzene causes acute myeloid leukemia and probably other hematological malignancies. As benzene also causes hematotoxicity even in workers exposed to levels below the US permissible occupational exposure limit of 1 part per million, further assessment of the health risks associated with its exposure, particularly at low levels, is needed. Here, we describe the probable mechanism by which benzene induces leukemia involving the targeting of critical genes and pathways through the induction of genetic, chromosomal or epigenetic abnormalities and genomic instability, in a hematopoietic stem cell (HSC); stromal cell dysregulation; apoptosis of HSCs and stromal cells and altered proliferation and differentiation of HSCs. These effects modulated by benzene-induced oxidative stress, aryl hydrocarbon receptor dysregulation and reduced immunosurveillance, lead to the generation of leukemic stem cells and subsequent clonal evolution to leukemia. A mode of action (MOA) approach to the risk assessment of benzene was recently proposed. This approach is limited, however, by the challenges of defining a simple stochastic MOA of benzene-induced leukemogenesis and of identifying relevant and quantifiable parameters associated with potential key events. An alternative risk assessment approach is the application of toxicogenomics and systems biology in human populations, animals and in vitro models of the HSC stem cell niche, exposed to a range of levels of benzene. These approaches will inform our understanding of the mechanisms of benzene toxicity and identify additional biomarkers of exposure, early effect and susceptibility useful for risk assessment.
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Affiliation(s)
| | | | - Martyn T. Smith
- Division of Environmental Health Sciences, Genes and Environment Laboratory, School of Public Health, University of California, Berkeley, CA 94720-7356, USA
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North M, Tandon VJ, Thomas R, Loguinov A, Gerlovina I, Hubbard AE, Zhang L, Smith MT, Vulpe CD. Genome-wide functional profiling reveals genes required for tolerance to benzene metabolites in yeast. PLoS One 2011; 6:e24205. [PMID: 21912624 PMCID: PMC3166172 DOI: 10.1371/journal.pone.0024205] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2010] [Accepted: 08/06/2011] [Indexed: 11/18/2022] Open
Abstract
Benzene is a ubiquitous environmental contaminant and is widely used in industry. Exposure to benzene causes a number of serious health problems, including blood disorders and leukemia. Benzene undergoes complex metabolism in humans, making mechanistic determination of benzene toxicity difficult. We used a functional genomics approach to identify the genes that modulate the cellular toxicity of three of the phenolic metabolites of benzene, hydroquinone (HQ), catechol (CAT) and 1,2,4-benzenetriol (BT), in the model eukaryote Saccharomyces cerevisiae. Benzene metabolites generate oxidative and cytoskeletal stress, and tolerance requires correct regulation of iron homeostasis and the vacuolar ATPase. We have identified a conserved bZIP transcription factor, Yap3p, as important for a HQ-specific response pathway, as well as two genes that encode putative NAD(P)H:quinone oxidoreductases, PST2 and YCP4. Many of the yeast genes identified have human orthologs that may modulate human benzene toxicity in a similar manner and could play a role in benzene exposure-related disease.
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Affiliation(s)
- Matthew North
- Department of Nutritional Science and Toxicology, University of California, Berkeley, California, United States of America
| | - Vickram J. Tandon
- Department of Nutritional Science and Toxicology, University of California, Berkeley, California, United States of America
| | - Reuben Thomas
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, California, United States of America
| | - Alex Loguinov
- Department of Nutritional Science and Toxicology, University of California, Berkeley, California, United States of America
| | - Inna Gerlovina
- Division of Biostatistics, School of Public Health, University of California, Berkeley, California, United States of America
| | - Alan E. Hubbard
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, California, United States of America
- Division of Biostatistics, School of Public Health, University of California, Berkeley, California, United States of America
| | - Luoping Zhang
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, California, United States of America
| | - Martyn T. Smith
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, California, United States of America
| | - Chris D. Vulpe
- Department of Nutritional Science and Toxicology, University of California, Berkeley, California, United States of America
- * E-mail:
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15
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Genotoxicity and apoptosis in Drosophila melanogaster exposed to benzene, toluene and xylene: Attenuation by quercetin and curcumin. Toxicol Appl Pharmacol 2011; 253:14-30. [DOI: 10.1016/j.taap.2011.03.006] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2010] [Revised: 02/11/2011] [Accepted: 03/07/2011] [Indexed: 12/18/2022]
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16
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Epigenetic modification involved in benzene-induced apoptosis through regulating apoptosis-related genes expression. Cell Biol Int 2011; 35:391-6. [DOI: 10.1042/cbi20100256] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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17
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Zhang L, McHale CM, Rothman N, Li G, Ji Z, Vermeulen R, Hubbard AE, Ren X, Shen M, Rappaport SM, North M, Skibola CF, Yin S, Vulpe C, Chanock SJ, Smith MT, Lan Q. Systems biology of human benzene exposure. Chem Biol Interact 2010; 184:86-93. [PMID: 20026094 PMCID: PMC2846187 DOI: 10.1016/j.cbi.2009.12.011] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2009] [Revised: 12/09/2009] [Accepted: 12/10/2009] [Indexed: 01/09/2023]
Abstract
Toxicogenomic studies, including genome-wide analyses of susceptibility genes (genomics), gene expression (transcriptomics), protein expression (proteomics), and epigenetic modifications (epigenomics), of human populations exposed to benzene are crucial to understanding gene-environment interactions, providing the ability to develop biomarkers of exposure, early effect and susceptibility. Comprehensive analysis of these toxicogenomic and epigenomic profiles by bioinformatics in the context of phenotypic endpoints, comprises systems biology, which has the potential to comprehensively define the mechanisms by which benzene causes leukemia. We have applied this approach to a molecular epidemiology study of workers exposed to benzene. Hematotoxicity, a significant decrease in almost all blood cell counts, was identified as a phenotypic effect of benzene that occurred even below 1 ppm benzene exposure. We found a significant decrease in the formation of progenitor colonies arising from bone marrow stem cells with increasing benzene exposure, showing that progenitor cells are more sensitive to the effects of benzene than mature blood cells, likely leading to the observed hematotoxicity. Analysis of transcriptomics by microarray in the peripheral blood mononuclear cells of exposed workers, identified genes and pathways (apoptosis, immune response, and inflammatory response) altered at high (>10 ppm) and low (<1 ppm) benzene levels. Serum proteomics by SELDI-TOF-MS revealed proteins consistently down-regulated in exposed workers. Preliminary epigenomics data showed effects of benzene on the DNA methylation of specific genes. Genomic screens for candidate genes involved in susceptibility to benzene toxicity are being undertaken in yeast, with subsequent confirmation by RNAi in human cells, to expand upon the findings from candidate gene analyses. Data on these and future biomarkers will be used to populate a large toxicogenomics database, to which we will apply bioinformatic approaches to understand the interactions among benzene toxicity, susceptibility genes, mRNA, and DNA methylation through a systems biology approach.
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Affiliation(s)
- Luoping Zhang
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, CA 94720-7356, USA.
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18
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Rossi ML, Ghosh AK, Bohr VA. Roles of Werner syndrome protein in protection of genome integrity. DNA Repair (Amst) 2010; 9:331-44. [PMID: 20075015 DOI: 10.1016/j.dnarep.2009.12.011] [Citation(s) in RCA: 146] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Werner syndrome protein (WRN) is one of a family of five human RecQ helicases implicated in the maintenance of genome stability. The conserved RecQ family also includes RecQ1, Bloom syndrome protein (BLM), RecQ4, and RecQ5 in humans, as well as Sgs1 in Saccharomyces cerevisiae, Rqh1 in Schizosaccharomyces pombe, and homologs in Caenorhabditis elegans, Xenopus laevis, and Drosophila melanogaster. Defects in three of the RecQ helicases, RecQ4, BLM, and WRN, cause human pathologies linked with cancer predisposition and premature aging. Mutations in the WRN gene are the causative factor of Werner syndrome (WS). WRN is one of the best characterized of the RecQ helicases and is known to have roles in DNA replication and repair, transcription, and telomere maintenance. Studies both in vitro and in vivo indicate that the roles of WRN in a variety of DNA processes are mediated by post-translational modifications, as well as several important protein-protein interactions. In this work, we will summarize some of the early studies on the cellular roles of WRN and highlight the recent findings that shed some light on the link between the protein with its cellular functions and the disease pathology.
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Affiliation(s)
- Marie L Rossi
- Laboratory of Molecular Gerontology, National Institute on Aging, Baltimore, MD 21224, USA
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Barreto G, Madureira D, Capani F, Aon-Bertolino L, Saraceno E, Alvarez-Giraldez LD. The role of catechols and free radicals in benzene toxicity: an oxidative DNA damage pathway. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2009; 50:771-80. [PMID: 19449395 DOI: 10.1002/em.20500] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Benzene is a widespread volatile compound and an environmental contaminant. Since it causes important toxic effects in workers exposed to low levels, long-term exposure to this compound has been extensively studied. Leukemia, blood disorders, bone marrow depression, and some types of cancer are directly related to benzene-initiated toxicity. Bioactivation of benzene can lead to the formation of hazardous metabolites such as phenol, hydroquinone, and catechol. Catechol forms semiquinones and reactive quinones that are presumed to play an important role in the generation of reactive oxygen species (ROS). ROS formation can directly induce single and double strand breaks in the DNA, oxidized nucleotides, and hyper-recombination, and consequently produces deleterious genetic changes. In this review, we have addressed the cytotoxic effects of benzene and its main metabolite, catechol, focusing on the oxidative pathway and further DNA damage.
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Ren X, Lim S, Smith MT, Zhang L. Werner syndrome protein, WRN, protects cells from DNA damage induced by the benzene metabolite hydroquinone. Toxicol Sci 2008; 107:367-75. [PMID: 19064679 DOI: 10.1093/toxsci/kfn254] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Werner syndrome (WS) is a rare autosomal progeroid disorder caused by a mutation in the gene encoding the WRN (Werner syndrome protein), a member of the RecQ family of helicases with a role in maintaining genomic stability. Genetic association studies have previously suggested a link between WRN and susceptibility to benzene-induced hematotoxicity. To further explore the role of WRN in benzene-induced hematotoxicity, we used short hairpin RNA to silence endogenous levels of WRN in the human HL60 acute promyelocytic cell line and subsequently exposed the cells to hydroquinone (HQ). Suppression of WRN led to an accelerated cell growth rate, increased susceptibility to hydroquinone-induced cytotoxicity and genotoxicity as measured by the single-cell gel electrophoresis assay, and an enhanced DNA damage response. More specifically, loss of WRN resulted in higher levels of early apoptosis, marked by increases in relative levels of cleaved caspase-7 and cleaved poly (ADP-ribose) polymerase 1, in cells treated with HQ compared with control cells. Our data suggests that WRN plays an important role in the surveillance of and protection against DNA damage induced by HQ. This provides mechanistic support for the link between WRN and benzene-induced hematotoxicity.
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Affiliation(s)
- Xuefeng Ren
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, California 94720, USA
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Lan Q, Zhang L, Shen M, Jo WJ, Vermeulen R, Li G, Vulpe C, Lim S, Ren X, Rappaport SM, Berndt SI, Yeager M, Yuenger J, Hayes RB, Linet M, Yin S, Chanock S, Smith MT, Rothman N. Large-scale evaluation of candidate genes identifies associations between DNA repair and genomic maintenance and development of benzene hematotoxicity. Carcinogenesis 2008; 30:50-8. [PMID: 18978339 DOI: 10.1093/carcin/bgn249] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Benzene is an established human hematotoxicant and leukemogen but its mechanism of action is unclear. To investigate the role of single-nucleotide polymorphisms (SNPs) on benzene-induced hematotoxicity, we analyzed 1395 SNPs in 411 genes using an Illumina GoldenGate assay in 250 benzene-exposed workers and 140 unexposed controls. Highly significant findings clustered in five genes (BLM, TP53, RAD51, WDR79 and WRN) that play a critical role in DNA repair and genomic maintenance, and these regions were then further investigated with tagSNPs. One or more SNPs in each gene were associated with highly significant 10-20% reductions (P values ranged from 0.0011 to 0.0002) in the white blood cell (WBC) count among benzene-exposed workers but not controls, with evidence for gene-environment interactions for SNPs in BLM, WRN and RAD51. Further, among workers exposed to benzene, the genotype-associated risk of having a WBC count <4000 cells/microl increased when using individuals with progressively higher WBC counts as the comparison group, with some odds ratios >8-fold. In vitro functional studies revealed that deletion of SGS1 in yeast, equivalent to lacking BLM and WRN function in humans, caused reduced cellular growth in the presence of the toxic benzene metabolite hydroquinone, and knockdown of WRN using specific short hairpin RNA increased susceptibility of human TK6 cells to hydroquinone toxicity. Our findings suggest that SNPs involved in DNA repair and genomic maintenance, with particular clustering in the homologous DNA recombination pathway, play an important role in benzene-induced hematotoxicity.
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Affiliation(s)
- Qing Lan
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20892, USA.
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