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Cox LA, Thompson WJ, Mundt KA. Interventional probability of causation (IPoC) with epidemiological and partial mechanistic evidence: benzene vs. formaldehyde and acute myeloid leukemia (AML). Crit Rev Toxicol 2024; 54:252-289. [PMID: 38753561 DOI: 10.1080/10408444.2024.2337435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Accepted: 03/25/2024] [Indexed: 05/18/2024]
Abstract
INTRODUCTION Causal epidemiology for regulatory risk analysis seeks to evaluate how removing or reducing exposures would change disease occurrence rates. We define interventional probability of causation (IPoC) as the change in probability of a disease (or other harm) occurring over a lifetime or other specified time interval that would be caused by a specified change in exposure, as predicted by a fully specified causal model. We define the closely related concept of causal assigned share (CAS) as the predicted fraction of disease risk that would be removed or prevented by a specified reduction in exposure, holding other variables fixed. Traditional approaches used to evaluate the preventable risk implications of epidemiological associations, including population attributable fraction (PAF) and the Bradford Hill considerations, cannot reveal whether removing a risk factor would reduce disease incidence. We argue that modern formal causal models coupled with causal artificial intelligence (CAI) and realistically partial and imperfect knowledge of underlying disease mechanisms, show great promise for determining and quantifying IPoC and CAS for exposures and diseases of practical interest. METHODS We briefly review key CAI concepts and terms and then apply them to define IPoC and CAS. We present steps to quantify IPoC using a fully specified causal Bayesian network (BN) model. Useful bounds for quantitative IPoC and CAS calculations are derived for a two-stage clonal expansion (TSCE) model for carcinogenesis and illustrated by applying them to benzene and formaldehyde based on available epidemiological and partial mechanistic evidence. RESULTS Causal BN models for benzene and risk of acute myeloid leukemia (AML) incorporating mechanistic, toxicological and epidemiological findings show that prolonged high-intensity exposure to benzene can increase risk of AML (IPoC of up to 7e-5, CAS of up to 54%). By contrast, no causal pathway leading from formaldehyde exposure to increased risk of AML was identified, consistent with much previous mechanistic, toxicological and epidemiological evidence; therefore, the IPoC and CAS for formaldehyde-induced AML are likely to be zero. CONCLUSION We conclude that the IPoC approach can differentiate between likely and unlikely causal factors and can provide useful upper bounds for IPoC and CAS for some exposures and diseases of practical importance. For causal factors, IPoC can help to estimate the quantitative impacts on health risks of reducing exposures, even in situations where mechanistic evidence is realistically incomplete and individual-level exposure-response parameters are uncertain. This illustrates the strength that can be gained for causal inference by using causal models to generate testable hypotheses and then obtaining toxicological data to test the hypotheses implied by the models-and, where necessary, refine the models. This virtuous cycle provides additional insight into causal determinations that may not be available from weight-of-evidence considerations alone.
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Affiliation(s)
- Louis A Cox
- Cox Associates and University of Colorado, Denver, CO, USA
| | | | - Kenneth A Mundt
- Independent Consultants in Epidemiology, Amherst, MA, USA
- Adjunct Professor of Epidemiology, University of Massachusetts, Amherst, MA, USA
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Vermeulen R, Lan Q, Qu Q, Linet MS, Zhang L, Li G, Portengen L, Vlaanderen J, Sungkyoon K, Hayes RB, Yin S, Smith MT, Rappaport SM, Rothman N. Nonlinear low dose hematotoxicity of benzene; a pooled analyses of two studies among Chinese exposed workers. ENVIRONMENT INTERNATIONAL 2023; 177:108007. [PMID: 37290291 DOI: 10.1016/j.envint.2023.108007] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Revised: 05/23/2023] [Accepted: 05/29/2023] [Indexed: 06/10/2023]
Abstract
BACKGROUND Impairment of the hematopoietic system is one of the primary adverse health effects from exposure to benzene. We previously have shown that exposure to benzene at low levels (<1 ppm) affects the blood forming system and that these effects were proportionally stronger at lower versus higher levels of benzene exposure. This observation is potentially explained by saturation of enzymatic systems. METHODS Here we extend these analyses by detailed modeling of the exposure response association of benzene and its major metabolites (i.e. catechol, muconic acid, phenol, and hydroquinone) on peripheral white blood cell (WBC) counts and its major cell-subtypes (i.e. granulocytes, lymphocytes, and monocytes) using two previously published cross-sectional studies among occupationally exposed Chinese workers. RESULTS Supra-linear exposure response associations were observed between air benzene concentrations (range ∼ 0.1 - 100 ppm) and WBC counts and its cell-subtypes, with a larger than proportional decrease in cell counts at lower than at higher levels of benzene exposure. The hematotoxicity associations were largely similar in shape when the analyses were repeated with benzene urinary metabolites suggesting that enzymatic saturation is not a full explanation of the observed non-linearity with WBC endpoints. DISCUSSION We hypothesize that the flattening of the exposure response curve especially at higher benzene exposure levels may reflect a response by the bone marrow to maintain hematopoietic homeostasis. Toxicity to the bone marrow and an induced hyper-proliferative response could both contribute to risk of subsequently developing a hematopoietic malignancy. Additional work is needed to explore this hypothesis.
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Affiliation(s)
- Roel Vermeulen
- Institute for Risk Assessment Sciences, Utrecht University, Utrecht, the Netherlands
| | - Qing Lan
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, DHHS, Bethesda, MD 20892, United States
| | - Qingshan Qu
- Nelson Institute of Environmental Medicine, New York University School of Medicine, Tuxedo, NY, United States
| | - Martha S Linet
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, DHHS, Bethesda, MD 20892, United States
| | - Luoping Zhang
- School of Public Health, University of California, Berkeley, CA 94720, United States
| | - Guilan Li
- Chinese Center for Disease Control and Prevention, Beijing, China
| | - Lutzen Portengen
- Institute for Risk Assessment Sciences, Utrecht University, Utrecht, the Netherlands
| | - Jelle Vlaanderen
- Institute for Risk Assessment Sciences, Utrecht University, Utrecht, the Netherlands
| | - Kim Sungkyoon
- School of Public Health, Seoul National University, Seoul, Republic of Korea
| | | | - Songnian Yin
- Chinese Center for Disease Control and Prevention, Beijing, China
| | - Martyn T Smith
- School of Public Health, University of California, Berkeley, CA 94720, United States
| | - Stephen M Rappaport
- School of Public Health, University of California, Berkeley, CA 94720, United States
| | - Nathaniel Rothman
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, DHHS, Bethesda, MD 20892, United States
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Abstract
Historically, benzene has been widely used in a large variety of applications. Occupational exposure limits (OELs) were set for benzene as it was found to be acutely toxic, causing central nervous system depression at high exposures. OELs were lowered when it was discovered that chronic exposure to benzene could cause haematotoxicity. After confirmation that benzene is a human carcinogen causing acute myeloid leukaemia and possibly other blood malignancies, OEL were further lowered. The industrial application of benzene as solvent is almost completely discontinued but it is still used as feedstock for the production of other materials, such as styrene. Occupational exposure to benzene may also occur since it is present in crude oil, natural gas condensate and a variety of petroleum products and because benzene can be formed in combustion of organic material. In the past few years, lower OELs for benzene in the range of 0.05-0.25 ppm have been proposed or were already established to protect workers from benzene-induced cancer. The skin is an important potential route of exposure and relatively more important at lower OELs. Consequently, human biomonitoring - which integrates all exposure routes - is routinely applied to control overall exposure to benzene. Several potential biomarkers have been proposed and investigated. For compliance check of the current low OELs, urinary S-phenylmercapturic acid (S-PMA), urinary benzene and blood benzene are feasible biomarkers. S-PMA appears to be the most promising biomarker but proper validation of biomarker levels corresponding to airborne benzene concentrations below 0.25 ppm are needed.
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Affiliation(s)
- Peter J Boogaard
- AFSG - Division of Toxicology, Wageningen University, Wageningen, The Netherlands
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Sager TM, Joseph P, Umbright CM, Hubbs AF, Barger M, Kashon ML, Fedan JS, Roberts JR. Biological effects of inhaled crude oil vapor. III. Pulmonary inflammation, cytotoxicity, and gene expression profile. Inhal Toxicol 2023; 35:241-253. [PMID: 37330949 PMCID: PMC10658288 DOI: 10.1080/08958378.2023.2224394] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 06/04/2023] [Indexed: 06/20/2023]
Abstract
OBJECTIVE Workers may be exposed to vapors emitted from crude oil in upstream operations in the oil and gas industry. Although the toxicity of crude oil constituents has been studied, there are very few in vivo investigations designed to mimic crude oil vapor (COV) exposures that occur in these operations. The goal of the current investigation was to examine lung injury, inflammation, oxidant generation, and effects on the lung global gene expression profile following a whole-body acute or sub-chronic inhalation exposure to COV. MATERIALS AND METHODS To conduct this investigation, rats were subjected to either a whole-body acute (6 hr) or a sub-chronic (28 d) inhalation exposure (6 hr/d × 4 d/wk × 4 wk) to COV (300 ppm; Macondo well surrogate oil). Control rats were exposed to filtered air. One and 28 d after acute exposure, and 1, 28, and 90 d following sub-chronic exposure, bronchoalveolar lavage was performed on the left lung to collect cells and fluid for analyses, the apical right lobe was preserved for histopathology, and the right cardiac and diaphragmatic lobes were processed for gene expression analyses. RESULTS No exposure-related changes were identified in histopathology, cytotoxicity, or lavage cell profiles. Changes in lavage fluid cytokines indicative of inflammation, immune function, and endothelial function after sub-chronic exposure were limited and varied over time. Minimal gene expression changes were detected only at the 28 d post-exposure time interval in both the exposure groups. CONCLUSION Taken together, the results from this exposure paradigm, including concentration, duration, and exposure chamber parameters, did not indicate significant and toxicologically relevant changes in markers of injury, oxidant generation, inflammation, and gene expression profile in the lung.
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Affiliation(s)
- Tina M Sager
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV, USA
| | - Pius Joseph
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV, USA
| | - Christina M Umbright
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV, USA
| | - Ann F Hubbs
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV, USA
| | - Mark Barger
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV, USA
| | - Michael L Kashon
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV, USA
| | - Jeffrey S Fedan
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV, USA
| | - Jenny R Roberts
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV, USA
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Phillips RV, Wei L, Cardenas A, Hubbard AE, McHale CM, Vermeulen R, Wei H, Smith MT, Zhang L, Lan Q, Rothman N. Epigenome-wide association studies of occupational exposure to benzene and formaldehyde. Epigenetics 2022; 17:2259-2277. [PMID: 36017556 PMCID: PMC9665125 DOI: 10.1080/15592294.2022.2115604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 08/04/2022] [Accepted: 08/17/2022] [Indexed: 11/03/2022] Open
Abstract
Sufficient evidence supports a relationship between certain myeloid neoplasms and exposure to benzene or formaldehyde. DNA methylation could underlie benzene- and formaldehyde-induced health outcomes, but data in exposed human populations are limited. We conducted two cross-sectional epigenome-wide association studies (EWAS), one in workers exposed to benzene and another in workers exposed to formaldehyde. Using HumanMethylation450 BeadChips, we investigated differences in blood cell DNA methylation among 50 benzene-exposed subjects and 48 controls, and among 31 formaldehyde-exposed subjects and 40 controls. We performed CpG-level and regional-level analyses. In the benzene EWAS, we found genome-wide significant alterations, i.e., FWER-controlled P-values <0.05, in the mean and variance of methylation at 22 and 318 CpG sites, respectively, and in mean methylation of a large genomic region. Pathway analysis of genes corresponding to benzene-associated differential methylation sites revealed an impact on the AMPK signalling pathway. In formaldehyde-exposed subjects compared to controls, 9 CpGs in the DUSP22 gene promoter had genome-wide significant decreased methylation variability and a large region of the HOXA5 promoter with 44 CpGs was hypomethylated. Our findings suggest that DNA methylation may contribute to the pathogenesis of diseases related to benzene and formaldehyde exposure. Aberrant expression and methylation of HOXA5 previously has been shown to be clinically significant in myeloid leukaemias. The tumour suppressor gene DUSP22 is a potential biomarker of exposure to formaldehyde, and irregularities have been associated with multiple exposures and diseases.
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Affiliation(s)
- Rachael V. Phillips
- School of Public Health, University of California at Berkeley, Berkeley, CA, USA
| | - Linqing Wei
- School of Public Health, University of California at Berkeley, Berkeley, CA, USA
| | - Andres Cardenas
- School of Public Health, University of California at Berkeley, Berkeley, CA, USA
| | - Alan E. Hubbard
- School of Public Health, University of California at Berkeley, Berkeley, CA, USA
| | - Cliona M. McHale
- School of Public Health, University of California at Berkeley, Berkeley, CA, USA
| | - Roel Vermeulen
- Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Universiteit Utrecht (UU), Utrecht, The Netherlands
| | - Hu Wei
- Division of Cancer Epidemiology and Genetics, Occupational and Environmental Epidemiology Branch, NCI, NIH, DHHS, Bethesda, MD, USA
| | - Martyn T. Smith
- School of Public Health, University of California at Berkeley, Berkeley, CA, USA
| | - Luoping Zhang
- School of Public Health, University of California at Berkeley, Berkeley, CA, USA
| | - Qing Lan
- Division of Cancer Epidemiology and Genetics, Occupational and Environmental Epidemiology Branch, NCI, NIH, DHHS, Bethesda, MD, USA
| | - Nathaniel Rothman
- Division of Cancer Epidemiology and Genetics, Occupational and Environmental Epidemiology Branch, NCI, NIH, DHHS, Bethesda, MD, USA
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Evaluating Phenotypic and Transcriptomic Responses Induced by Low-Level VOCs in Zebrafish: Benzene as an Example. TOXICS 2022; 10:toxics10070351. [PMID: 35878256 PMCID: PMC9324908 DOI: 10.3390/toxics10070351] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Revised: 06/23/2022] [Accepted: 06/24/2022] [Indexed: 11/16/2022]
Abstract
Urban environments are plagued by complex mixtures of anthropogenic volatile organic compounds (VOCs), such as mixtures of benzene, toluene, ethylene, and xylene (BTEX). Sources of BTEX that drive human exposure include vehicle exhaust, industrial emissions, off-gassing of building material, as well as oil spillage and leakage. Among the BTEX mixture, benzene is the most volatile compound and has been linked to numerous adverse health outcomes. However, few studies have focused on the effects of low-level benzene on exposure during early development, which is a susceptible window when hematological, immune, metabolic, and detoxification systems are immature. In this study, we used zebrafish to conduct a VOC exposure model and evaluated phenotypic and transcriptomic responses following 0.1 and 1 ppm benzene exposure during the first five days of embryogenesis (n = 740 per treatment). The benzene body burden was 2 mg/kg in 1 ppm-exposed larval zebrafish pools and under the detection limit in 0.1 ppm-exposed fish. No observable phenotypic changes were found in both larvae except for significant skeletal deformities in 0.1 ppm-exposed fish (p = 0.01) compared with unexposed fish. Based on transcriptomic responses, 1 ppm benzene dysregulated genes that were implicated with the development of hematological system, and the regulation of oxidative stress response, fatty acid metabolism, immune system, and inflammatory response, including apob, nfkbiaa, serpinf1, foxa1, cyp2k6, and cyp2n13 from the cytochrome P450 gene family. Key genes including pik3c2b, pltp, and chia.2 were differentially expressed in both 1 and 0.1 ppm exposures. However, fewer transcriptomic changes were induced by 0.1 ppm compared with 1 ppm. Future studies are needed to determine if these transcriptomic responses during embryogenesis have long-term consequences at levels equal to or lower than 1 ppm.
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Chow PW, Abd Hamid Z, Mathialagan RD, Rajab NF, Shuib S, Sulong S. Clastogenicity and Aneugenicity of 1,4-Benzoquinone in Different Lineages of Mouse Hematopoietic Stem/Progenitor Cells. TOXICS 2021; 9:toxics9050107. [PMID: 34065823 PMCID: PMC8150741 DOI: 10.3390/toxics9050107] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Revised: 05/03/2021] [Accepted: 05/07/2021] [Indexed: 11/16/2022]
Abstract
Previous reports on hematotoxicity and leukemogenicity related to benzene exposure highlighted its adverse effects on hematopoiesis. Despite the reported findings, studies concerning the mechanism of benzene affecting chromosomal integrity in lineage-committed hematopoietic stem/progenitor cells (HSPCs) remain unclear. Here, we studied the clastogenicity and aneugenicity of benzene in lineage-committed HSPCs via karyotyping. Isolated mouse bone marrow cells (MBMCs) were exposed to the benzene metabolite 1,4-benzoquinone (1,4-BQ) at 1.25, 2.5, 5, 7, and 12 μM for 24 h, followed by karyotyping. Then, the chromosomal aberration (CA) in 1,4-BQ-exposed hematopoietic progenitor cells (HPCs) comprising myeloid, Pre-B lymphoid, and erythroid lineages were evaluated following colony-forming cell (CFC) assay. Percentage of CA, predominantly via Robertsonian translocation (Rb), was increased significantly (p < 0.05) in MBMCs and all progenitors at all concentrations. As a comparison, Pre-B lymphoid progenitor demonstrated a significantly higher percentage of CA (p < 0.05) than erythroid progenitor at 1.25, 2.5, and 7 μM as well as a significantly higher percentage (p < 0.05) than myeloid progenitor at 7 μM of 1,4-BQ. In conclusion, 1,4-BQ induced CA, particularly via Rb in both MBMCs and HPCs, notably via a lineage-dependent response. The role of lineage specificity in governing the clastogenicity and aneugenicity of 1,4-BQ deserves further investigation.
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Affiliation(s)
- Paik Wah Chow
- Biomedical Science Programme and Center for Diagnostic, Therapeutic and Investigative Studies, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur 50300, Malaysia; (P.W.C.); (R.D.M.)
| | - Zariyantey Abd Hamid
- Biomedical Science Programme and Center for Diagnostic, Therapeutic and Investigative Studies, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur 50300, Malaysia; (P.W.C.); (R.D.M.)
- Correspondence: ; Tel.: +60-3-9289-7196
| | - Ramya Dewi Mathialagan
- Biomedical Science Programme and Center for Diagnostic, Therapeutic and Investigative Studies, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur 50300, Malaysia; (P.W.C.); (R.D.M.)
| | - Nor Fadilah Rajab
- Biomedical Science Programme and Center for Healthy Ageing & Wellness, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur 50300, Malaysia;
| | - Salwati Shuib
- Department of Pathology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur 56000, Malaysia;
| | - Sarina Sulong
- Human Genome Center, School of Medical Sciences, Health Campus, Universiti Sains Malaysia, Kelantan 16150, Malaysia;
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Cellular and Molecular Mechanisms of Environmental Pollutants on Hematopoiesis. Int J Mol Sci 2020; 21:ijms21196996. [PMID: 32977499 PMCID: PMC7583016 DOI: 10.3390/ijms21196996] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 09/20/2020] [Accepted: 09/21/2020] [Indexed: 02/07/2023] Open
Abstract
Hematopoiesis is a complex and intricate process that aims to replenish blood components in a constant fashion. It is orchestrated mostly by hematopoietic progenitor cells (hematopoietic stem cells (HSCs)) that are capable of self-renewal and differentiation. These cells can originate other cell subtypes that are responsible for maintaining vital functions, mediate innate and adaptive immune responses, provide tissues with oxygen, and control coagulation. Hematopoiesis in adults takes place in the bone marrow, which is endowed with an extensive vasculature conferring an intense flow of cells. A myriad of cell subtypes can be found in the bone marrow at different levels of activation, being also under constant action of an extensive amount of diverse chemical mediators and enzymatic systems. Bone marrow platelets, mature erythrocytes and leukocytes are delivered into the bloodstream readily available to meet body demands. Leukocytes circulate and reach different tissues, returning or not returning to the bloodstream. Senescent leukocytes, specially granulocytes, return to the bone marrow to be phagocytized by macrophages, restarting granulopoiesis. The constant high production and delivery of cells into the bloodstream, alongside the fact that blood cells can also circulate between tissues, makes the hematopoietic system a prime target for toxic agents to act upon, making the understanding of the bone marrow microenvironment vital for both toxicological sciences and risk assessment. Environmental and occupational pollutants, therapeutic molecules, drugs of abuse, and even nutritional status can directly affect progenitor cells at their differentiation and maturation stages, altering behavior and function of blood compounds and resulting in impaired immune responses, anemias, leukemias, and blood coagulation disturbances. This review aims to describe the most recently investigated molecular and cellular toxicity mechanisms of current major environmental pollutants on hematopoiesis in the bone marrow.
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Mathialagan RD, Abd Hamid Z, Ng QM, Rajab NF, Shuib S, Binti Abdul Razak SR. Bone Marrow Oxidative Stress and Acquired Lineage-Specific Genotoxicity in Hematopoietic Stem/Progenitor Cells Exposed to 1,4-Benzoquinone. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17165865. [PMID: 32823552 PMCID: PMC7459782 DOI: 10.3390/ijerph17165865] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Revised: 08/05/2020] [Accepted: 08/07/2020] [Indexed: 12/23/2022]
Abstract
Hematopoietic stem/progenitor cells (HSPCs) are susceptible to benzene-induced genotoxicity. However, little is known about the mechanism of DNA damage response affecting lineage-committed progenitors for myeloid, erythroid, and lymphoid. Here, we investigated the genotoxicity of a benzene metabolite, 1,4-benzoquinone (1,4-BQ), in HSPCs using oxidative stress and lineage-directed approaches. Mouse bone marrow cells (BMCs) were exposed to 1,4-BQ (1.25–12 μM) for 24 h, followed by oxidative stress and genotoxicity assessments. Then, the genotoxicity of 1,4-BQ in lineage-committed progenitors was evaluated using colony forming cell assay following 7–14 days of culture. 1,4-BQ exposure causes significant decreases (p < 0.05) in glutathione level and superoxide dismutase activity, along with significant increases (p < 0.05) in levels of malondialdehyde and protein carbonyls. 1,4-BQ exposure induces DNA damage in BMCs by significantly (p < 0.05) increased percentages of DNA in tail at 7 and 12 μM and tail moment at 12 μM. We found crucial differences in genotoxic susceptibility based on percentages of DNA in tail between lineage-committed progenitors. Myeloid and pre-B lymphoid progenitors appeared to acquire significant DNA damage as compared with the control starting from a low concentration of 1,4-BQ exposure (2.5 µM). In contrast, the erythroid progenitor showed significant damage as compared with the control starting at 5 µM 1,4-BQ. Meanwhile, a significant (p < 0.05) increase in tail moment was only notable at 7 µM and 12 µM 1,4-BQ exposure for all progenitors. Benzene could mediate hematological disorders by promoting bone marrow oxidative stress and lineage-specific genotoxicity targeting HSPCs.
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Affiliation(s)
- Ramya Dewi Mathialagan
- Biomedical Science Programme and Centre for Diagnostic, Therapeutic and Investigative Studies, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur 53000, Malaysia; (R.D.M.); (Q.M.N.)
| | - Zariyantey Abd Hamid
- Biomedical Science Programme and Centre for Diagnostic, Therapeutic and Investigative Studies, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur 53000, Malaysia; (R.D.M.); (Q.M.N.)
- Correspondence:
| | - Qing Min Ng
- Biomedical Science Programme and Centre for Diagnostic, Therapeutic and Investigative Studies, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur 53000, Malaysia; (R.D.M.); (Q.M.N.)
| | - Nor Fadilah Rajab
- Biomedical Science Programme and Center for Healthy Ageing & Wellness, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur 53000, Malaysia;
| | - Salwati Shuib
- Department of Pathology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Yaacob Latif, Bandar Tun Razak, Cheras, Kuala Lumpur 56000, Malaysia;
| | - Siti Razila Binti Abdul Razak
- Oncological and Radiological Sciences Cluster, Advanced Medical & Dental Institute, Universiti Sains Malaysia, Kepala Batas Bertam, Pulau Pinang 13200, Malaysia;
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Dewi R, Hamid ZA, Rajab NF, Shuib S, Razak SA. Genetic, epigenetic, and lineage-directed mechanisms in benzene-induced malignancies and hematotoxicity targeting hematopoietic stem cells niche. Hum Exp Toxicol 2019; 39:577-595. [PMID: 31884827 DOI: 10.1177/0960327119895570] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Benzene is a known hematotoxic and leukemogenic agent with hematopoietic stem cells (HSCs) niche being the potential target. Occupational and environmental exposure to benzene has been linked to the incidences of hematological disorders and malignancies. Previous studies have shown that benzene may act via multiple modes of action targeting HSCs niche, which include induction of chromosomal and micro RNA aberrations, leading to genetic and epigenetic modification of stem cells and probable carcinogenesis. However, understanding the mechanism linking benzene to the HSCs niche dysregulation is challenging due to complexity of its microenvironment. The niche is known to comprise of cell populations accounted for HSCs and their committed progenitors of lymphoid, erythroid, and myeloid lineages. Thus, it is fundamental to address novel approaches via lineage-directed strategy to elucidate precise mechanism involved in benzene-induced toxicity targeting HSCs and progenitors of different lineages. Here, we review the key genetic and epigenetic factors that mediate hematotoxicological effects by benzene and its metabolites in targeting HSCs niche. Overall, the use of combined genetic, epigenetic, and lineage-directed strategies targeting the HSCs niche is fundamental to uncover the key mechanisms in benzene-induced hematological disorders and malignancies.
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Affiliation(s)
- R Dewi
- Biomedical Science Programme and Centre of Applied and Health Sciences, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - Z Abdul Hamid
- Biomedical Science Programme and Centre of Applied and Health Sciences, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - N F Rajab
- Biomedical Science Programme and Centre of Applied and Health Sciences, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - S Shuib
- Department of Pathology, Universiti Kebangsaan Malaysia Medical Centre, Jalan Yaacob Latif, Bandar Tun Razak, Kuala Lumpur, Malaysia
| | - Sr Abdul Razak
- Oncological and Radiological Sciences Cluster, Advanced Medical & Dental Institute, Universiti Sains Malaysia, Pulau Pinang, Malaysia
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Krewski D, Andersen ME, Tyshenko MG, Krishnan K, Hartung T, Boekelheide K, Wambaugh JF, Jones D, Whelan M, Thomas R, Yauk C, Barton-Maclaren T, Cote I. Toxicity testing in the 21st century: progress in the past decade and future perspectives. Arch Toxicol 2019; 94:1-58. [DOI: 10.1007/s00204-019-02613-4] [Citation(s) in RCA: 124] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 11/05/2019] [Indexed: 12/19/2022]
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12
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Jørgensen KM, Færgestad Mosleth E, Hovde Liland K, Hopf NB, Holdhus R, Stavrum AK, Gjertsen BT, Kirkeleit J. Global Gene Expression Response in Peripheral Blood Cells of Petroleum Workers Exposed to Sub-Ppm Benzene Levels. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2018; 15:ijerph15112385. [PMID: 30373255 PMCID: PMC6266895 DOI: 10.3390/ijerph15112385] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 10/21/2018] [Accepted: 10/24/2018] [Indexed: 01/14/2023]
Abstract
Altered gene expression in pathways relevant to leukaemogenesis, as well as reduced levels of circulating lymphocytes, have been reported in workers that were exposed to benzene concentrations below 1 ppm. In this study, we analysed whole blood global gene expression patterns in a worker cohort with altered levels of T cells and immunoglobulins IgM and IgA at three time points; pre-shift, post-shift (after three days), and post-recovery (12 hours later). Eight benzene exposed tank workers performing maintenance work in crude oil cargo tanks with a mean benzene exposure of 0.3 ppm (range 0.1–0.5 ppm) and five referents considered to be unexposed were examined by gene expression arrays. By using our data as independent validation, we reanalysed selected genes that were reported to be altered from previous studies of workers being exposed to sub-ppm benzene levels Four out of six genes previously proposed as marker genes in chronically exposed workers separated benzene exposed workers from unexposed referents (CLEC5, ACSL1, PRG2, IFNB1). Even better separation of benzene exposed workers and referents was observed for short-term exposure for genes in the Jak-STAT pathway, particularly elevated expression of IL6 and reduced expression of IL19.
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Affiliation(s)
- Katarina M Jørgensen
- Department of Clinical Science, University of Bergen, P.O. Box 7804, N-5020 Bergen, Norway.
- Institute of Marine Research, P.O. Box 1870 Nordnes, N-5817 Bergen, Norway.
| | | | - Kristian Hovde Liland
- Nofima AS, Osloveien 1, N-1430 Ås, Norway.
- Faculty of Science and Technology, Norwegian University of Life Sciences, NO-1430 Ås, Norway.
| | - Nancy B Hopf
- Institute for Work and Health (IST), Universities of Lausanne and Geneva, CH-1066 Lausanne-Epalinges, Switzerland.
| | - Rita Holdhus
- Department of Clinical Science, University of Bergen, P.O. Box 7804, N-5020 Bergen, Norway.
- Department of Medical Genetics, Haukeland University Hospital, P.O. Box 1400, N-5021 Bergen, Norway.
| | - Anne-Kristin Stavrum
- Department of Clinical Science, University of Bergen, P.O. Box 7804, N-5020 Bergen, Norway.
- Department of Medical Genetics, Haukeland University Hospital, P.O. Box 1400, N-5021 Bergen, Norway.
| | - Bjørn Tore Gjertsen
- Center for Cancer Biomarkers (CCBIO), Department of Clinical Science, Precision Oncology Research Group, University of Bergen, P.O. Box 7804, N-5020 Bergen, Norway.
| | - Jorunn Kirkeleit
- Department of Clinical Science, University of Bergen, P.O. Box 7804, N-5020 Bergen, Norway.
- Department of Global Public Health and Primary Care, University of Bergen, P.O. Box 7804, N-5020 Bergen, Norway.
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13
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Schiffman C, McHale CM, Hubbard AE, Zhang L, Thomas R, Vermeulen R, Li G, Shen M, Rappaport SM, Yin S, Lan Q, Smith MT, Rothman N. Identification of gene expression predictors of occupational benzene exposure. PLoS One 2018; 13:e0205427. [PMID: 30300410 PMCID: PMC6177191 DOI: 10.1371/journal.pone.0205427] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 09/25/2018] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Previously, using microarrays and mRNA-Sequencing (mRNA-Seq) we found that occupational exposure to a range of benzene levels perturbed gene expression in peripheral blood mononuclear cells. OBJECTIVES In the current study, we sought to identify gene expression biomarkers predictive of benzene exposure below 1 part per million (ppm), the occupational standard in the U.S. METHODS First, we used the nCounter platform to validate altered expression of 30 genes in 33 unexposed controls and 57 subjects exposed to benzene (<1 to ≥5 ppm). Second, we used SuperLearner (SL) to identify a minimal number of genes for which altered expression could predict <1 ppm benzene exposure, in 44 subjects with a mean air benzene level of 0.55±0.248 ppm (minimum 0.203ppm). RESULTS nCounter and microarray expression levels were highly correlated (coefficients >0.7, p<0.05) for 26 microarray-selected genes. nCounter and mRNA-Seq levels were poorly correlated for 4 mRNA-Seq-selected genes. Using negative binomial regression with adjustment for covariates and multiple testing, we confirmed differential expression of 23 microarray-selected genes in the entire benzene-exposed group, and 27 genes in the <1 ppm-exposed subgroup, compared with the control group. Using SL, we identified 3 pairs of genes that could predict <1 ppm benzene exposure with cross-validated AUC estimates >0.9 (p<0.0001) and were not predictive of other exposures (nickel, arsenic, smoking, stress). The predictive gene pairs are PRG2/CLEC5A, NFKBI/CLEC5A, and ACSL1/CLEC5A. They play roles in innate immunity and inflammatory responses. CONCLUSIONS Using nCounter and SL, we validated the altered expression of multiple mRNAs by benzene and identified gene pairs predictive of exposure to benzene at levels below the US occupational standard of 1ppm.
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Affiliation(s)
- Courtney Schiffman
- School of Public Health, University of California, Berkeley, California, United States of America
| | - Cliona M. McHale
- School of Public Health, University of California, Berkeley, California, United States of America
| | - Alan E. Hubbard
- School of Public Health, University of California, Berkeley, California, United States of America
| | - Luoping Zhang
- School of Public Health, University of California, Berkeley, California, United States of America
| | - Reuben Thomas
- School of Public Health, University of California, Berkeley, California, United States of America
| | - Roel Vermeulen
- Institute of Risk assessment Sciences, Utrecht University, Utrecht, the Netherlands
| | - Guilan Li
- Institute of Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Min Shen
- Occupational and Environmental Epidemiology Branch, Division of Cancer Epidemiology and Genetics, NCI, NIH, DHHS, Bethesda, Maryland, United States of America
| | - Stephen M. Rappaport
- School of Public Health, University of California, Berkeley, California, United States of America
| | - Songnian Yin
- Institute of Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Qing Lan
- Occupational and Environmental Epidemiology Branch, Division of Cancer Epidemiology and Genetics, NCI, NIH, DHHS, Bethesda, Maryland, United States of America
| | - Martyn T. Smith
- School of Public Health, University of California, Berkeley, California, United States of America
| | - Nathaniel Rothman
- Occupational and Environmental Epidemiology Branch, Division of Cancer Epidemiology and Genetics, NCI, NIH, DHHS, Bethesda, Maryland, United States of America
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14
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Sauer E, Gauer B, Nascimento S, Nardi J, Göethel G, Costa B, Correia D, Matte U, Charão M, Arbo M, Duschl A, Moro A, Garcia SC. The role of B7 costimulation in benzene immunotoxicity and its potential association with cancer risk. ENVIRONMENTAL RESEARCH 2018; 166:91-99. [PMID: 29883905 DOI: 10.1016/j.envres.2018.05.029] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 05/24/2018] [Accepted: 05/26/2018] [Indexed: 06/08/2023]
Abstract
Benzene is a recognized human carcinogen; however, there are still some gaps in the knowledge regarding the mechanism of toxicity of this organic solvent and potential early biomarkers for the damage caused by it. In a previous study, our research group demonstrated that the adhesion molecules of the immune system (B7.1 and B7.2) could be potential biomarkers in the early detection of immunotoxicity caused by benzene exposure. Therefore, this study was developed to deepen the understanding regarding this important topic, aiming to contribute to the comprehension of the benzene toxicity mechanism mediated by B7.1 and B7.2 and its potential association with the risk of carcinogenicity. B7.1 and B7.2 protein expression in blood monocytes and B7.1 and B7.2 gene expression in PBMCs were evaluated. Additionally, complement C3 and C4 levels in serum were measured, as well as p53 gene expression in PBMCs. Seventy-four gas station workers (GSW group) and 71 non-occupationally exposed subjects (NEG) were evaluated. Our results demonstrated decreased levels of B7.1 and B7.2 protein and gene expression in the GSW group compared to the NEG (n = 71) (p < 0.01). Along the same lines, decreased levels of the complement system were observed in the GSW group (p < 0.01), demonstrating the impairment of this immune system pathway as well. Additionally, a reduction was observed in p53 gene expression in the GSA group (p < 0.01). These alterations were associated with both the benzene exposure biomarker evaluated, urinary trans, trans-muconic acid, and with exposure time (p < 0.05). Moreover, strong correlations were observed between the gene expression of p53 vs. B7.1 (r = 0.830; p < 0.001), p53 vs. B7.2 (r = 0.685; p < 0.001), and B7.1 vs. B7.2 (r = 0.702; p < 0.001). Taken together, these results demonstrate that the immune system co-stimulatory molecule pathway is affected by benzene exposure. Also, the decrease in p53 gene expression, even at low exposure levels, reinforces the carcinogenicity effect of benzene in this pathway. Therefore, our results suggest that the promotion of immune evasion together with a decrease in p53 gene expression may play an important role in the benzene toxicity mechanism. However, further and targeted studies are needed to confirm this proposition.
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Affiliation(s)
- Elisa Sauer
- Laboratório de Toxicologia (LATOX), Departamento de Análises, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil; Programa de Pós Graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Bruna Gauer
- Laboratório de Toxicologia (LATOX), Departamento de Análises, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil; Programa de Pós Graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Sabrina Nascimento
- Laboratório de Toxicologia (LATOX), Departamento de Análises, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil; Programa de Pós Graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Jessica Nardi
- Laboratório de Toxicologia (LATOX), Departamento de Análises, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil; Programa de Pós Graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Gabriela Göethel
- Laboratório de Toxicologia (LATOX), Departamento de Análises, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil; Programa de Pós Graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Bárbara Costa
- Laboratório de Toxicologia (LATOX), Departamento de Análises, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Douglas Correia
- Laboratório de Toxicologia (LATOX), Departamento de Análises, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil; Programa de Pós Graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Ursula Matte
- Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Mariele Charão
- Instituto de Ciências das Saúde, Universidade Feevale, Novo Hamburgo, RS, Brazil
| | - Marcelo Arbo
- Laboratório de Toxicologia (LATOX), Departamento de Análises, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil; Programa de Pós Graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Albert Duschl
- Department of Molecular Biology, University of Salzburg, Salzburg, Austria
| | - Angela Moro
- Faculdade Especializada na Área de Saúde do Rio Grande do Sul, Passo Fundo, RS, Brazil
| | - Solange Cristina Garcia
- Laboratório de Toxicologia (LATOX), Departamento de Análises, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil; Programa de Pós Graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil.
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15
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Boogaard PJ. The low-dose benzene debate needs a sharp blade. Chem Biol Interact 2017; 278:239-241. [PMID: 28655485 DOI: 10.1016/j.cbi.2017.06.023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 06/12/2017] [Accepted: 06/22/2017] [Indexed: 11/30/2022]
Affiliation(s)
- Peter J Boogaard
- Shell Health, Shell International bv, Wageningen University & Research, The Netherlands
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16
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Jiménez-Garza O, Guo L, Byun HM, Carrieri M, Bartolucci GB, Barrón-Vivanco BS, Baccarelli AA. Aberrant promoter methylation in genes related to hematopoietic malignancy in workers exposed to a VOC mixture. Toxicol Appl Pharmacol 2017; 339:65-72. [PMID: 29217486 DOI: 10.1016/j.taap.2017.12.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 11/30/2017] [Accepted: 12/03/2017] [Indexed: 12/20/2022]
Abstract
Occupational exposure to volatile organic compounds (VOCs) may cause hematopoietic malignancy, either by single exposure to benzene or possibly due to a concomitant exposure to several VOCs. Since oxidative stress, inflammation and DNA repair pathways are closely involved in cancer development, the effect of VOC exposure on expression of proteins involved in these pathways has been studied, but epigenetic changes have not been well described. Here, DNA methylation status following occupational exposure to a VOC mixture was assessed by bisulfite sequencing of the promoter regions of seven genes involved in the mentioned pathways. Peripheral blood samples and individual-level VOC exposure data were obtained from healthy leather shoe factory workers (LS, n=40) and gas station attendants (GS, n=36), as well as a reference group of university employees (C, n=66). Exposure levels for acetone, ethylbenzene, methyl ethyl ketone, n-hexane, toluene and xylene were higher in LS (p<0.001); benzene and methyl acetate levels were higher in GS (p<0.001). TOP2A, SOD1, and TNF-α promoter methylation status was increased in LS (p<0.05). In LS, we also found significant correlations between GSTP1 promoter methylation and both iNOS (r=0.37, p=0.008) and COX-2 (r=-0.38, p=0.007) methylation. In exposed groups, ethylbenzene exposure levels showed a significant correlation with TOP2A methylation (β=0.33). Our results show early, toxic effects at the epigenetic level caused by occupational exposure to high levels of a VOC mixture. These subcellular modifications may represent the initial mechanism of toxicity leading to hematopoietic malignancy, possibly due to a synergistic, hematotoxic effect of VOC mixtures.
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Affiliation(s)
- Octavio Jiménez-Garza
- Health Sciences Division, University of Guanajuato, León, Campus. Blvd. Puente del Mienio 1001, Fracción del Predio San Carlos, C.P. 37670 León Guanajuato, Mexico.
| | - Liqiong Guo
- Department of Occupational & Environmental Health, Tianjin Medical University, No.22 Qixiangtai Road, Heping District, Tianjin 300070, China
| | - Hyang-Min Byun
- Human Nutrition Research Centre, Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne NE4 5PL, United Kingdom
| | - Mariella Carrieri
- Department of Cardiologic, Thoracic and Vascular Science, University of Padova, Via Giustiniani, 2, 35128 Padova, Italy
| | - Giovanni Battista Bartolucci
- Department of Cardiologic, Thoracic and Vascular Science, University of Padova, Via Giustiniani, 2, 35128 Padova, Italy
| | - Briscia Socorro Barrón-Vivanco
- The Laboratory of Environmental Toxicology and Pollution, Autonomous University of Nayarit, Av de la Cultura Amado Nervo S/N, CP 36000 Tepic, Nayarit, Mexico
| | - Andrea A Baccarelli
- The Laboratory of Human Environmental Epigenetics, Harvard T.H. Chan School of Public Health, 677 Huntington Avenue, Boston, MA 02115, USA
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17
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Cox LA, Schnatter AR, Boogaard PJ, Banton M, Ketelslegers HB. Non-parametric estimation of low-concentration benzene metabolism. Chem Biol Interact 2017; 278:242-255. [DOI: 10.1016/j.cbi.2017.08.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 07/14/2017] [Accepted: 08/10/2017] [Indexed: 11/25/2022]
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18
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Jiménez-Garza O, Guo L, Byun HM, Carrieri M, Bartolucci GB, Zhong J, Baccarelli AA. Promoter methylation status in genes related with inflammation, nitrosative stress and xenobiotic metabolism in low-level benzene exposure: Searching for biomarkers of oncogenesis. Food Chem Toxicol 2017; 109:669-676. [DOI: 10.1016/j.fct.2017.08.019] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 08/15/2017] [Indexed: 12/13/2022]
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19
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Cote I, Andersen ME, Ankley GT, Barone S, Birnbaum LS, Boekelheide K, Bois FY, Burgoon LD, Chiu WA, Crawford-Brown D, Crofton KM, DeVito M, Devlin RB, Edwards SW, Guyton KZ, Hattis D, Judson RS, Knight D, Krewski D, Lambert J, Maull EA, Mendrick D, Paoli GM, Patel CJ, Perkins EJ, Poje G, Portier CJ, Rusyn I, Schulte PA, Simeonov A, Smith MT, Thayer KA, Thomas RS, Thomas R, Tice RR, Vandenberg JJ, Villeneuve DL, Wesselkamper S, Whelan M, Whittaker C, White R, Xia M, Yauk C, Zeise L, Zhao J, DeWoskin RS. The Next Generation of Risk Assessment Multi-Year Study-Highlights of Findings, Applications to Risk Assessment, and Future Directions. ENVIRONMENTAL HEALTH PERSPECTIVES 2016; 124:1671-1682. [PMID: 27091369 PMCID: PMC5089888 DOI: 10.1289/ehp233] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Revised: 10/30/2015] [Accepted: 03/29/2016] [Indexed: 05/19/2023]
Abstract
BACKGROUND The Next Generation (NexGen) of Risk Assessment effort is a multi-year collaboration among several organizations evaluating new, potentially more efficient molecular, computational, and systems biology approaches to risk assessment. This article summarizes our findings, suggests applications to risk assessment, and identifies strategic research directions. OBJECTIVE Our specific objectives were to test whether advanced biological data and methods could better inform our understanding of public health risks posed by environmental exposures. METHODS New data and methods were applied and evaluated for use in hazard identification and dose-response assessment. Biomarkers of exposure and effect, and risk characterization were also examined. Consideration was given to various decision contexts with increasing regulatory and public health impacts. Data types included transcriptomics, genomics, and proteomics. Methods included molecular epidemiology and clinical studies, bioinformatic knowledge mining, pathway and network analyses, short-duration in vivo and in vitro bioassays, and quantitative structure activity relationship modeling. DISCUSSION NexGen has advanced our ability to apply new science by more rapidly identifying chemicals and exposures of potential concern, helping characterize mechanisms of action that influence conclusions about causality, exposure-response relationships, susceptibility and cumulative risk, and by elucidating new biomarkers of exposure and effects. Additionally, NexGen has fostered extensive discussion among risk scientists and managers and improved confidence in interpreting and applying new data streams. CONCLUSIONS While considerable uncertainties remain, thoughtful application of new knowledge to risk assessment appears reasonable for augmenting major scope assessments, forming the basis for or augmenting limited scope assessments, and for prioritization and screening of very data limited chemicals. Citation: Cote I, Andersen ME, Ankley GT, Barone S, Birnbaum LS, Boekelheide K, Bois FY, Burgoon LD, Chiu WA, Crawford-Brown D, Crofton KM, DeVito M, Devlin RB, Edwards SW, Guyton KZ, Hattis D, Judson RS, Knight D, Krewski D, Lambert J, Maull EA, Mendrick D, Paoli GM, Patel CJ, Perkins EJ, Poje G, Portier CJ, Rusyn I, Schulte PA, Simeonov A, Smith MT, Thayer KA, Thomas RS, Thomas R, Tice RR, Vandenberg JJ, Villeneuve DL, Wesselkamper S, Whelan M, Whittaker C, White R, Xia M, Yauk C, Zeise L, Zhao J, DeWoskin RS. 2016. The Next Generation of Risk Assessment multiyear study-highlights of findings, applications to risk assessment, and future directions. Environ Health Perspect 124:1671-1682; http://dx.doi.org/10.1289/EHP233.
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Affiliation(s)
- Ila Cote
- National Center for Environmental Assessment, U.S. Environmental Protection Agency (EPA), Washington, District of Columbia, USA
- Address correspondence to I. Cote, U.S. Environmental Protection Agency, Region 8, Room 8152, 1595 Wynkoop St., Denver, CO 80202-1129 USA. Telephone: (202) 288-9539. E-mail:
| | | | - Gerald T. Ankley
- National Health and Environmental Effects Research Laboratory, U.S. EPA, Duluth, Minnesota, USA
| | - Stanley Barone
- Office of Chemical Safety and Pollution Prevention, U.S. EPA, Washington, District of Columbia, USA
| | - Linda S. Birnbaum
- National Institute of Environmental Health Sciences, and
- National Toxicology Program, National Institutes of Health (NIH), Department of Health and Human Services (DHHS), Research Triangle Park, North Carolina, USA
| | - Kim Boekelheide
- Department of Pathology and Laboratory Medicine, Brown University, Providence, Rhode Island, USA
| | - Frederic Y. Bois
- Unité Modèles pour l’Écotoxicologie et la Toxicologie, Institut National de l’Environnement Industriel et des Risques, Verneuil en Halatte, France
| | - Lyle D. Burgoon
- U.S. Army Engineer Research and Development Center, Research Triangle Park, North Carolina, USA
| | - Weihsueh A. Chiu
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | | | | | - Michael DeVito
- National Institute of Environmental Health Sciences, and
- National Toxicology Program, National Institutes of Health (NIH), Department of Health and Human Services (DHHS), Research Triangle Park, North Carolina, USA
| | - Robert B. Devlin
- National Health and Environmental Effects Research Laboratory, U.S. EPA, Research Triangle Park, North Carolina, USA
| | - Stephen W. Edwards
- National Health and Environmental Effects Research Laboratory, U.S. EPA, Research Triangle Park, North Carolina, USA
| | | | - Dale Hattis
- George Perkins Marsh Institute, Clark University, Worcester, Massachusetts, USA
| | | | - Derek Knight
- European Chemicals Agency, Annankatu, Helsinki, Finland
| | - Daniel Krewski
- McLaughlin Centre for Population Health Risk Assessment, University of Ottawa, Ottawa, Ontario, Canada
| | - Jason Lambert
- National Center for Environmental Assessment, U.S. EPA, Cincinnati, Ohio, USA
| | - Elizabeth Anne Maull
- National Institute of Environmental Health Sciences, and
- National Toxicology Program, National Institutes of Health (NIH), Department of Health and Human Services (DHHS), Research Triangle Park, North Carolina, USA
| | - Donna Mendrick
- National Center for Toxicological Research, Food and Drug Administration, Jefferson, Arkansas, USA
| | | | - Chirag Jagdish Patel
- Department of Biomedical Informatics, Harvard Medical School, Boston, Massachusetts, USA
| | - Edward J. Perkins
- U.S. Army Engineer Research and Development Center, Vicksburg, Mississippi, USA
| | - Gerald Poje
- Grant Consulting Group, Washington, District of Columbia, USA
| | | | - Ivan Rusyn
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - Paul A. Schulte
- Education and Information Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Cincinnati, Ohio, USA
| | - Anton Simeonov
- National Center for Advancing Translational Sciences, NIH, DHHS, Bethesda, Maryland, USA
| | - Martyn T. Smith
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, Berkeley, California, USA
| | - Kristina A. Thayer
- National Institute of Environmental Health Sciences, and
- National Toxicology Program, National Institutes of Health (NIH), Department of Health and Human Services (DHHS), Research Triangle Park, North Carolina, USA
| | | | - Reuben Thomas
- Gladstone Institutes, University of California, San Francisco, San Francisco, California, USA
| | - Raymond R. Tice
- National Institute of Environmental Health Sciences, and
- National Toxicology Program, National Institutes of Health (NIH), Department of Health and Human Services (DHHS), Research Triangle Park, North Carolina, USA
| | - John J. Vandenberg
- National Center for Environmental Assessment, U.S. Environmental Protection Agency (EPA), Washington, District of Columbia, USA
| | - Daniel L. Villeneuve
- National Health and Environmental Effects Research Laboratory, U.S. EPA, Duluth, Minnesota, USA
| | - Scott Wesselkamper
- National Center for Environmental Assessment, U.S. EPA, Cincinnati, Ohio, USA
| | - Maurice Whelan
- Systems Toxicology Unit, European Commission Joint Research Centre, Ispra, Italy
| | - Christine Whittaker
- Education and Information Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Cincinnati, Ohio, USA
| | - Ronald White
- Center for Effective Government, Washington, District of Columbia, USA
| | - Menghang Xia
- National Center for Advancing Translational Sciences, NIH, DHHS, Bethesda, Maryland, USA
| | - Carole Yauk
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario, Canada
| | - Lauren Zeise
- Office of Environmental Health Hazard Assessment, California EPA, Oakland, California, USA
| | - Jay Zhao
- National Center for Environmental Assessment, U.S. EPA, Cincinnati, Ohio, USA
| | - Robert S. DeWoskin
- National Center for Environmental Assessment, U.S. Environmental Protection Agency (EPA), Washington, District of Columbia, USA
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20
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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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21
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Liu L, Ling X, Wu M, Chen J, Chen S, Tan Q, Chen J, Liu J, Zou F. Rb silencing mediated by the down-regulation of MeCP2 is involved in cell transformation induced by long-term exposure to hydroquinone. Mol Carcinog 2016; 56:651-663. [DOI: 10.1002/mc.22523] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 06/04/2016] [Accepted: 07/01/2016] [Indexed: 11/11/2022]
Affiliation(s)
- Linhua Liu
- Department of Occupational Health and Occupational Medicine; Guangdong Provincial Key Laboratory of Tropical Disease Research; School of Public Health and Tropical Medicine; Southern Medical University; Guangzhou PR China
- Department of Environmental and Occupational Health; Dongguan Key Laboratory of Environmental Medicine; School of Public Health; Guangdong Medical University; Dongguan PR China
| | - Xiaoxuan Ling
- Department of Environmental and Occupational Health; Dongguan Key Laboratory of Environmental Medicine; School of Public Health; Guangdong Medical University; Dongguan PR China
- School of Public Health; Guangzhou Medical University; Guangzhou PR China
| | - Minhua Wu
- Department of Histology and Embryology; Guangdong Medical University; Zhanjiang PR China
| | - Jialong Chen
- Department of Occupational Health and Occupational Medicine; Guangdong Provincial Key Laboratory of Tropical Disease Research; School of Public Health and Tropical Medicine; Southern Medical University; Guangzhou PR China
- Department of Environmental and Occupational Health; Dongguan Key Laboratory of Environmental Medicine; School of Public Health; Guangdong Medical University; Dongguan PR China
| | - Shaoqiao Chen
- Department of Clinical Laboratory; The First Affiliated Hospital of Sun Yat-sen University; Guangzhou PR China
| | - Qiang Tan
- Foshan Institute of Occupational Disease Prevention and Control; Foshan PR China
| | - Jiansong Chen
- School of Public Health; Guangzhou Medical University; Guangzhou PR China
| | - Jiaxian Liu
- Department of Environmental and Occupational Health; Dongguan Key Laboratory of Environmental Medicine; School of Public Health; Guangdong Medical University; Dongguan PR China
| | - Fei Zou
- Department of Occupational Health and Occupational Medicine; Guangdong Provincial Key Laboratory of Tropical Disease Research; School of Public Health and Tropical Medicine; Southern Medical University; Guangzhou PR China
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22
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Liu D, Chen Y, Sun P, Bai W, Gao A. STAT3 methylation in white blood cells as a novel sensitive biomarker for the toxic effect of low-dose benzene exposure. Toxicol Res (Camb) 2016; 5:800-807. [PMID: 30090390 PMCID: PMC6061912 DOI: 10.1039/c5tx00445d] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Accepted: 01/20/2016] [Indexed: 12/13/2022] Open
Abstract
Alterations in DNA methylation patterns play an essential role in disease process and are associated with cancer risk. To explore the toxic effect and early sensitive biomarker of the health effects of low-dose benzene exposure (LDBE), and investigate the correlation between DNA methylation and the toxic effect of LDBE, a cross-sectional study was conducted in a sample of 571 workers; 312 workers who were exposed to a 1.82 ± 1.16 mg m-3 air benzene concentration were assigned to the LDBE group, while 259 non-known benzene exposure (NBE) workers were assigned to the control group, with an air benzene concentration of 0.06 ± 0.01 mg m-3. Routine blood indexes, alanine transaminase (ALT), oxidative stress parameters and signal transducer and activator of transcription 3 (STAT3) methylation were detected. Compared with the NBE population, the STAT3 methylation level (P = 0.001), Platelets (PLTs) (P = 0.002) and 8-isoprostane-PGFs (8-iso-PGF2a) (P = 0.001) manifested a significant reduction, while ALT (P = 0.002) and 8-hydroxy-2 deoxyguanosine (8-OHdG) (P = 0.002) showed a significant rise in the LDBE population. In addition, a significant correlation was observed between STAT3 methylation and oxidative stress, namely 8-OhdG and 8-iso-PGF2a. Furthermore, a multivariate analysis showed that the STAT3 methylation (structure loadings = 0.909) was the most strongly correlated with the other set of variables, especially with white blood cells (WBCs) (structure loadings = 0.675). Taken together, STAT3 methylation may be the underlying mechanism involved in the early toxic effect of LDBE, therefore, STAT3 methylation can be a novel sensitive biomarker for the toxic effect of low-dose benzene exposure.
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Affiliation(s)
- Di Liu
- Department of Occupational Health and Environmental Health , School of Public Health , Capital Medical University , Beijing 100069 , China . ; ; Tel: +86-10-83911509
- Beijing Key Laboratory of Environmental Toxicology , Capital Medical University , Beijing 100069 , China
| | - Yujiao Chen
- Department of Occupational Health and Environmental Health , School of Public Health , Capital Medical University , Beijing 100069 , China . ; ; Tel: +86-10-83911509
- Beijing Key Laboratory of Environmental Toxicology , Capital Medical University , Beijing 100069 , China
| | - Pengling Sun
- Department of Occupational Health and Environmental Health , School of Public Health , Capital Medical University , Beijing 100069 , China . ; ; Tel: +86-10-83911509
- Beijing Key Laboratory of Environmental Toxicology , Capital Medical University , Beijing 100069 , China
| | - Wenlin Bai
- Department of Occupational Health and Environmental Health , School of Public Health , Capital Medical University , Beijing 100069 , China . ; ; Tel: +86-10-83911509
- Beijing Key Laboratory of Environmental Toxicology , Capital Medical University , Beijing 100069 , China
| | - Ai Gao
- Department of Occupational Health and Environmental Health , School of Public Health , Capital Medical University , Beijing 100069 , China . ; ; Tel: +86-10-83911509
- Beijing Key Laboratory of Environmental Toxicology , Capital Medical University , Beijing 100069 , China
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23
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Omics for prediction of environmental health effects: Blood leukocyte-based cross-omic profiling reliably predicts diseases associated with tobacco smoking. Sci Rep 2016; 6:20544. [PMID: 26837704 PMCID: PMC4738297 DOI: 10.1038/srep20544] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 01/06/2016] [Indexed: 01/13/2023] Open
Abstract
The utility of blood-based omic profiles for linking environmental exposures to their potential health effects was evaluated in 649 individuals, drawn from the general population, in relation to tobacco smoking, an exposure with well-characterised health effects. Using disease connectivity analysis, we found that the combination of smoking-modified, genome-wide gene (including miRNA) expression and DNA methylation profiles predicts with remarkable reliability most diseases and conditions independently known to be causally associated with smoking (indicative estimates of sensitivity and positive predictive value 94% and 84%, respectively). Bioinformatics analysis reveals the importance of a small number of smoking-modified, master-regulatory genes and suggest a central role for altered ubiquitination. The smoking-induced gene expression profiles overlap significantly with profiles present in blood cells of patients with lung cancer or coronary heart disease, diseases strongly associated with tobacco smoking. These results provide proof-of-principle support to the suggestion that omic profiling in peripheral blood has the potential of identifying early, disease-related perturbations caused by toxic exposures and may be a useful tool in hazard and risk assessment.
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24
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Jennen DGJ, van Leeuwen DM, Hendrickx DM, Gottschalk RWH, van Delft JHM, Kleinjans JCS. Bayesian Network Inference Enables Unbiased Phenotypic Anchoring of Transcriptomic Responses to Cigarette Smoke in Humans. Chem Res Toxicol 2015; 28:1936-48. [PMID: 26360787 DOI: 10.1021/acs.chemrestox.5b00145] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Microarray-based transcriptomic analysis has been demonstrated to hold the opportunity to study the effects of human exposure to, e.g., chemical carcinogens at the whole genome level, thus yielding broad-ranging molecular information on possible carcinogenic effects. Since genes do not operate individually but rather through concerted interactions, analyzing and visualizing networks of genes should provide important mechanistic information, especially upon connecting them to functional parameters, such as those derived from measurements of biomarkers for exposure and carcinogenic risk. Conventional methods such as hierarchical clustering and correlation analyses are frequently used to address these complex interactions but are limited as they do not provide directional causal dependence relationships. Therefore, our aim was to apply Bayesian network inference with the purpose of phenotypic anchoring of modified gene expressions. We investigated a use case on transcriptomic responses to cigarette smoking in humans, in association with plasma cotinine levels as biomarkers of exposure and aromatic DNA-adducts in blood cells as biomarkers of carcinogenic risk. Many of the genes that appear in the Bayesian networks surrounding plasma cotinine, and to a lesser extent around aromatic DNA-adducts, hold biologically relevant functions in inducing severe adverse effects of smoking. In conclusion, this study shows that Bayesian network inference enables unbiased phenotypic anchoring of transcriptomics responses. Furthermore, in all inferred Bayesian networks several dependencies are found which point to known but also to new relationships between the expression of specific genes, cigarette smoke exposure, DNA damaging-effects, and smoking-related diseases, in particular associated with apoptosis, DNA repair, and tumor suppression, as well as with autoimmunity.
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Affiliation(s)
- Danyel G J Jennen
- Department of Toxicogenomics, Maastricht University , Universiteitssingel 40, 6229 ER Maastricht, The Netherlands
| | - Danitsja M van Leeuwen
- Department of Toxicogenomics, Maastricht University , Universiteitssingel 40, 6229 ER Maastricht, The Netherlands
| | - Diana M Hendrickx
- Department of Toxicogenomics, Maastricht University , Universiteitssingel 40, 6229 ER Maastricht, The Netherlands
| | - Ralph W H Gottschalk
- Department of Toxicogenomics, Maastricht University , Universiteitssingel 40, 6229 ER Maastricht, The Netherlands
| | - Joost H M van Delft
- Department of Toxicogenomics, Maastricht University , Universiteitssingel 40, 6229 ER Maastricht, The Netherlands
| | - Jos C S Kleinjans
- Department of Toxicogenomics, Maastricht University , Universiteitssingel 40, 6229 ER Maastricht, The Netherlands
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Health risks in international container and bulk cargo transport due to volatile toxic compounds. J Occup Med Toxicol 2015; 10:19. [PMID: 26075009 PMCID: PMC4465480 DOI: 10.1186/s12995-015-0059-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Accepted: 04/27/2015] [Indexed: 11/10/2022] Open
Abstract
To ensure the preservation and quality of the goods, physical (i.e. radiation) or chemical pest control is needed. The dark side of such consents may bear health risks in international transport and production sharing. In fact, between 10% and 20% of all containers arriving European harbors were shown to contain volatile toxic substances above the exposure limit values. Possible exposure to these toxic chemicals may occur not only for the applicators but also the receiver by off gassing from products, packing materials or transport units like containers. A number of intoxications, some with lethal outcome, occur not only during the fumigation, but also during freight transport (on bulk carriers and other transport vessels), as well as in the logistic lines during loading and unloading. Risk occupations include dock-workers, seafarers, inspectors, as well as the usually uninformed workers of importing enterprises that unload the products. Bystanders as well as vulnerable consumers may also be at risk. Ongoing studies focus on the release of these toxic volatile substances from various goods. It was shown that the half-lives of the off-gassing process range between minutes and months, depending on the toxic substance, its chemical reactivity, concentration, the temperature, the contaminated matrix (goods and packing materials), and the packing density in the transport units. Regulations on declaration and handling dangerous goods are mostly not followed. It is obvious that this hazardous situation in freight transport urgently requires preventive steps. In order to improve awareness and relevant knowledge there is a need for more comprehensive information on chemical hazards and a broader implementation of the already existing regulations and guidelines, such as those from ILO, IMO, and national authorities. It is also necessary to have regular controls by the authorities on a worldwide scale, which should be followed by sanctions in case of disregarding regulations. Further, fumigated containers must have a warning sign corresponding to international recommendations and national regulations, and freight documents have to indicate any potential hazard during stripping the goods.
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26
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Volatile organic compounds in bile for early diagnosis of cholangiocarcinoma in patients with primary sclerosing cholangitis: a pilot study. Gastrointest Endosc 2015; 81:943-9.e1. [PMID: 25500329 PMCID: PMC4375033 DOI: 10.1016/j.gie.2014.09.041] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Accepted: 09/12/2014] [Indexed: 12/17/2022]
Abstract
BACKGROUND The diagnosis of cholangiocarcinoma (CCA) in patients with primary sclerosing cholangitis (PSC) is particularly difficult. The role of volatile organic compounds (VOCs) for diagnosis of CCA in patients with PSC is not known. OBJECTIVE Our aim was to identify potential VOCs in the headspaces (gas above the sample) in bile that may predict CCA in patients with PSC. DESIGN Prospective cross-sectional study. SETTING Referral center. PATIENTS A total of 32 patients undergoing ERCP for PSC and for CCA complicating PSC. INTERVENTIONS ERCP, bile aspiration. MAIN OUTCOME MEASUREMENTS Selected ion flow tube mass spectrometry was used to analyze the concentration of 22 prevalent VOCs in bile samples. Logistic regression analysis was performed to build a predictive model for diagnosis of CCA. RESULTS Levels of several compounds (ethanol, acrylonitrile, acetonitrile, acetaldehyde, benzene, carbon disulfide, dimethyl sulfide, 2-propranolol) were significantly different in patients with CCA complicating PSC compared with those having PSC (P < .05). By using receiver operating characteristic curve analysis, we developed a model for the diagnosis of CCA adjusted for age and sex based on VOC levels of acrylonitrile, 3-methyl hexane, and benzene. The model (2.3239*log [acrylonitrile] + 0.9871*log [3-methyl hexane] + 0.8448*log [benzene]) < -0.12 identified the patients with CCA (area under the curve [AUC] = 0.89), with 90.5% sensitivity and 72.7% specificity (P = .02). LIMITATIONS Sample size. CONCLUSION The measurement of VOCs in biliary fluid may be useful to diagnose CCA in patients with PSC. A larger study with a longitudinal study design is required to confirm our pilot observations to diagnose CCA early in patients with PSC. ( CLINICAL TRIAL REGISTRATION NUMBER NCT01565460.).
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27
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Chaussabel D. Assessment of immune status using blood transcriptomics and potential implications for global health. Semin Immunol 2015; 27:58-66. [PMID: 25823891 DOI: 10.1016/j.smim.2015.03.002] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Revised: 03/02/2015] [Accepted: 03/03/2015] [Indexed: 12/17/2022]
Abstract
The immune system plays a key role in health maintenance and pathogenesis of a wide range of diseases. Leukocytes that are present in the blood convey valuable information about the status of the immune system. Blood transcriptomics, which consists in profiling blood transcript abundance on genome-wide scales, has gained in popularity over the past several years. Indeed, practicality and simplicity largely makes up for what this approach may lack in terms of cell population-level resolution. An extensive survey of the literature reveals increasingly widespread use across virtually all fields of medicine as well as across a number of different animal species, including model organisms but also animals of economical importance. Dissemination across such a wide range of disciplines holds the promise of adding a new perspective, breadth or context, to the considerable depth afforded by whole genome profiling of blood transcript abundance. Indeed, it is only through such contextualization that a truly global perspective will be gained from the use of systems approaches. Also discussed are opportunities that may arise for the fields of immunology and medicine from using blood transcriptomics as a common denominator for developing interactions and cooperation across fields of research that have traditionally been and largely remain compartmentalized. Finally, an argument is made for building immunology research capacity using blood transcriptomics platforms in low-resource and high-disease burden settings.
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28
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De Palma G, Manno M. Metabolic polymorphisms and biomarkers of effect in the biomonitoring of occupational exposure to low-levels of benzene: state of the art. Toxicol Lett 2014; 231:194-204. [PMID: 25447454 DOI: 10.1016/j.toxlet.2014.10.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Revised: 10/07/2014] [Accepted: 10/09/2014] [Indexed: 12/21/2022]
Abstract
Current levels of occupational exposure to benzene, a genotoxic human carcinogen, in Western countries are reduced by two-three orders of magnitude (from ppm to ppb) as compared to the past. However, as benzene toxicity is strongly dependent on biotransformation and recent evidence underlines a higher efficiency of bio-activation pathways at lower levels of exposure, toxic effects at low doses could be higher than expected, particularly in susceptible individuals. Currently, biological monitoring can allow accurate exposure assessment, relying on sensitive and specific enough biomarkers of internal dose. The availability of similarly reliable biomarkers of early effect or susceptibility could greatly improve the risk assessment process to such an extent that risk could even be assessed at the individual level. As to susceptibility biomarkers, functional genetic polymorphisms of relevant biotransformation enzymes may modulate the risk of adverse effects (NQO1) and the levels of biomarkers of internal dose, in particular S-phenylmercapturic acid (GSTM1, GSTT1, GSTA1). Among biomarkers of early effect, genotoxicity indicators, although sensitive in some cases, are too aspecific for routine use in occupational health surveillance programmes. Currently only the periodical blood cell count seems suitable enough to be applied in the longitudinal monitoring of effects from benzene exposure. Novel biomarkers of early effect are expected from higher collaboration among toxicologists and clinicians, also using advanced "omics" techniques.
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Affiliation(s)
- G De Palma
- Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, Section of Public Health and Human Sciences, University of Brescia, Piazzale Spedali Civili 1, 25123 Brescia, Italy.
| | - M Manno
- Department of Public Health, Section of Occupational Medicine and Toxicology, University of Napoli Federico II, Via S. Pansini, 5, 80131 Napoli, Italy
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Krewski D, Westphal M, Andersen ME, Paoli GM, Chiu WA, Al-Zoughool M, Croteau MC, Burgoon LD, Cote I. A framework for the next generation of risk science. ENVIRONMENTAL HEALTH PERSPECTIVES 2014; 122:796-805. [PMID: 24727499 PMCID: PMC4123023 DOI: 10.1289/ehp.1307260] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Accepted: 04/09/2014] [Indexed: 05/19/2023]
Abstract
OBJECTIVES In 2011, the U.S. Environmental Protection Agency initiated the NexGen project to develop a new paradigm for the next generation of risk science. METHODS The NexGen framework was built on three cornerstones: the availability of new data on toxicity pathways made possible by fundamental advances in basic biology and toxicological science, the incorporation of a population health perspective that recognizes that most adverse health outcomes involve multiple determinants, and a renewed focus on new risk assessment methodologies designed to better inform risk management decision making. RESULTS The NexGen framework has three phases. Phase I (objectives) focuses on problem formulation and scoping, taking into account the risk context and the range of available risk management decision-making options. Phase II (risk assessment) seeks to identify critical toxicity pathway perturbations using new toxicity testing tools and technologies, and to better characterize risks and uncertainties using advanced risk assessment methodologies. Phase III (risk management) involves the development of evidence-based population health risk management strategies of a regulatory, economic, advisory, community-based, or technological nature, using sound principles of risk management decision making. CONCLUSIONS Analysis of a series of case study prototypes indicated that many aspects of the NexGen framework are already beginning to be adopted in practice.
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Affiliation(s)
- Daniel Krewski
- McLaughlin Centre for Population Health Risk Assessment, University of Ottawa, Ottawa, Ontario, Canada
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