1
|
Ro SH, Bae J, Jang Y, Myers JF, Chung S, Yu J, Natarajan SK, Franco R, Song HS. Arsenic Toxicity on Metabolism and Autophagy in Adipose and Muscle Tissues. Antioxidants (Basel) 2022; 11:antiox11040689. [PMID: 35453374 PMCID: PMC9028583 DOI: 10.3390/antiox11040689] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 03/28/2022] [Accepted: 03/29/2022] [Indexed: 02/04/2023] Open
Abstract
Arsenic, a naturally occurring metalloid derived from the environment, has been studied worldwide for its causative effects in various cancers. However, the effects of arsenic toxicity on the development and progression of metabolic syndrome, including obesity and diabetes, has received less attention. Many studies suggest that metabolic dysfunction and autophagy dysregulation of adipose and muscle tissues are closely related to the development of metabolic disease. In the USA, arsenic contamination has been reported in some ground water, soil and grain samples in major agricultural regions, but the effects on adipose and muscle tissue metabolism and autophagy have not been investigated much. Here, we highlight arsenic toxicity according to the species, dose and exposure time and the effects on adipose and muscle tissue metabolism and autophagy. Historically, arsenic was used as both a poison and medicine, depending on the dose and treatment time. In the modern era, arsenic intoxication has significantly increased due to exposure from water, soil and food, which could be a contributing factor in the development and progression of metabolic disease. From this review, a better understanding of the pathogenic mechanisms by which arsenic alters metabolism and autophagy regulation could become a cornerstone leading to the development of therapeutic strategies against arsenic-induced toxicity and metabolic disease.
Collapse
Affiliation(s)
- Seung-Hyun Ro
- Department of Biochemistry and the Redox Biology Center, University of Nebraska-Lincoln, Lincoln, NE 68588, USA; (J.B.); (Y.J.); (J.F.M.)
- Correspondence: ; Tel.: +1-402-472-5424; Fax:+1-402-472-7842
| | - Jiyoung Bae
- Department of Biochemistry and the Redox Biology Center, University of Nebraska-Lincoln, Lincoln, NE 68588, USA; (J.B.); (Y.J.); (J.F.M.)
- Department of Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
| | - Yura Jang
- Department of Biochemistry and the Redox Biology Center, University of Nebraska-Lincoln, Lincoln, NE 68588, USA; (J.B.); (Y.J.); (J.F.M.)
- Department of Neurology, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Laboratory of Immunology, Office of Biotechnology Products, Center for Drug Evaluation and Research, United States Food and Drug Administration, Silver Spring, MD 20993, USA
| | - Jacob F. Myers
- Department of Biochemistry and the Redox Biology Center, University of Nebraska-Lincoln, Lincoln, NE 68588, USA; (J.B.); (Y.J.); (J.F.M.)
- Department of Microbiology and Immunology, Sidney Kimmel Medical College and Jefferson College of Life Sciences, MD-PhD Program, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Soonkyu Chung
- Department of Nutrition, University of Massachusetts, Amherst, MA 01003, USA;
| | - Jiujiu Yu
- Department of Nutrition and Health Sciences, University of Nebraska-Lincoln, Lincoln, NE 68583, USA; (J.Y.); (S.K.N.)
| | - Sathish Kumar Natarajan
- Department of Nutrition and Health Sciences, University of Nebraska-Lincoln, Lincoln, NE 68583, USA; (J.Y.); (S.K.N.)
| | - Rodrigo Franco
- School of Veterinary Medicine and Biomedical Sciences and the Redox Biology Center, University of Nebraska-Lincoln, Lincoln, NE 68583, USA;
| | - Hyun-Seob Song
- Department of Biological Systems Engineering, University of Nebraska-Lincoln, Lincoln, NE 68583, USA;
- Department of Food Science and Technology, Nebraska Food for Health Center, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| |
Collapse
|
2
|
Chakraborty A, Ghosh S, Biswas B, Pramanik S, Nriagu J, Bhowmick S. Epigenetic modifications from arsenic exposure: A comprehensive review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 810:151218. [PMID: 34717984 DOI: 10.1016/j.scitotenv.2021.151218] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 10/19/2021] [Accepted: 10/21/2021] [Indexed: 06/13/2023]
Abstract
Arsenic is a notorious element with the potential to harm exposed individuals in ways that include cancerous and non-cancerous health complications. Millions of people across the globe (especially in South and Southeast Asian countries including China, Vietnam, India and Bangladesh) are currently being unknowingly exposed to precarious levels of arsenic. Among the diverse effects associated with such arsenic levels of exposure is the propensity to alter the epigenome. Although a large volume of literature exists on arsenic-induced genotoxicity, cytotoxicity, and inter-individual susceptibility due to active research on these subject areas from the last millennial, it is only recently that attention has turned on the ramifications and mechanisms of arsenic-induced epigenetic changes. The present review summarizes the possible mechanisms involved in arsenic induced epigenetic alterations. It focuses on the mechanisms underlying epigenome reprogramming from arsenic exposure that result in improper cell signaling and dysfunction of various epigenetic components. The mechanistic information articulated from the review is used to propose a number of novel therapeutic strategies with a potential for ameliorating the burden of worldwide arsenic poisoning.
Collapse
Affiliation(s)
- Arijit Chakraborty
- Kolkata Zonal Center, CSIR-National Environmental Engineering Research Institute (NEERI), Kolkata, West Bengal 700107, India
| | - Soma Ghosh
- Kolkata Zonal Center, CSIR-National Environmental Engineering Research Institute (NEERI), Kolkata, West Bengal 700107, India
| | - Bratisha Biswas
- Kolkata Zonal Center, CSIR-National Environmental Engineering Research Institute (NEERI), Kolkata, West Bengal 700107, India
| | - Sreemanta Pramanik
- Kolkata Zonal Center, CSIR-National Environmental Engineering Research Institute (NEERI), Kolkata, West Bengal 700107, India
| | - Jerome Nriagu
- Department of Environmental Health Sciences, School of Public Health, University of Michigan, 109 Observatory Street, Ann Arbor, MI 48109-2029, USA
| | - Subhamoy Bhowmick
- Kolkata Zonal Center, CSIR-National Environmental Engineering Research Institute (NEERI), Kolkata, West Bengal 700107, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India.
| |
Collapse
|
3
|
Laine VN, Verschuuren M, van Oers K, Espín S, Sánchez-Virosta P, Eeva T, Ruuskanen S. Does Arsenic Contamination Affect DNA Methylation Patterns in a Wild Bird Population? An Experimental Approach. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:8947-8954. [PMID: 34110128 DOI: 10.1101/2020.12.08.415745] [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] [Indexed: 05/24/2023]
Abstract
Pollutants, such as toxic metals, negatively influence organismal health and performance, even leading to population collapses. Studies in model organisms have shown that epigenetic marks, such as DNA methylation, can be modulated by various environmental factors, including pollutants, influencing gene expression, and various organismal traits. Yet experimental data on the effects of pollution on DNA methylation from wild animal populations are largely lacking. We here experimentally investigated for the first time the effects of early-life exposure to environmentally relevant levels of a key pollutant, arsenic (As), on genome-wide DNA methylation in a wild bird population. We experimentally exposed nestlings of great tits (Parus major) to arsenic during their postnatal developmental period (3 to 14 days post-hatching) and compared their erythrocyte DNA methylation levels to those of respective controls. In contrast to predictions, we found no overall hypomethylation in the arsenic group. We found evidence for loci to be differentially methylated between the treatment groups, but for five CpG sites only. Three of the sites were located in gene bodies of zinc finger and BTB domain containing 47 (ZBTB47), HIVEP zinc finger 3 (HIVEP3), and insulin-like growth factor 2 mRNA binding protein 1 (IGF2BP1). Further studies are needed to evaluate whether epigenetic dysregulation is a commonly observed phenomenon in polluted populations and what are the consequences for organism functioning and for population dynamics.
Collapse
Affiliation(s)
- Veronika N Laine
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen 6708 PB, The Netherlands
| | - Mark Verschuuren
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen 6708 PB, The Netherlands
| | - Kees van Oers
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen 6708 PB, The Netherlands
| | - Silvia Espín
- Area of Toxicology, Department of Socio-Sanitary Sciences, University of Murcia, Murcia 30003, Spain
- Department of Biology, University of Turku, Turku 20500, Finland
| | - Pablo Sánchez-Virosta
- Area of Toxicology, Department of Socio-Sanitary Sciences, University of Murcia, Murcia 30003, Spain
- Department of Biology, University of Turku, Turku 20500, Finland
| | - Tapio Eeva
- Department of Biology, University of Turku, Turku 20500, Finland
| | - Suvi Ruuskanen
- Department of Biology, University of Turku, Turku 20500, Finland
- Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä 40014, Finland
| |
Collapse
|
4
|
Laine V, Verschuuren M, van Oers K, Espín S, Sánchez-Virosta P, Eeva T, Ruuskanen S. Does Arsenic Contamination Affect DNA Methylation Patterns in a Wild Bird Population? An Experimental Approach. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:8947-8954. [PMID: 34110128 PMCID: PMC8277128 DOI: 10.1021/acs.est.0c08621] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Pollutants, such as toxic metals, negatively influence organismal health and performance, even leading to population collapses. Studies in model organisms have shown that epigenetic marks, such as DNA methylation, can be modulated by various environmental factors, including pollutants, influencing gene expression, and various organismal traits. Yet experimental data on the effects of pollution on DNA methylation from wild animal populations are largely lacking. We here experimentally investigated for the first time the effects of early-life exposure to environmentally relevant levels of a key pollutant, arsenic (As), on genome-wide DNA methylation in a wild bird population. We experimentally exposed nestlings of great tits (Parus major) to arsenic during their postnatal developmental period (3 to 14 days post-hatching) and compared their erythrocyte DNA methylation levels to those of respective controls. In contrast to predictions, we found no overall hypomethylation in the arsenic group. We found evidence for loci to be differentially methylated between the treatment groups, but for five CpG sites only. Three of the sites were located in gene bodies of zinc finger and BTB domain containing 47 (ZBTB47), HIVEP zinc finger 3 (HIVEP3), and insulin-like growth factor 2 mRNA binding protein 1 (IGF2BP1). Further studies are needed to evaluate whether epigenetic dysregulation is a commonly observed phenomenon in polluted populations and what are the consequences for organism functioning and for population dynamics.
Collapse
Affiliation(s)
- Veronika
N. Laine
- Department
of Animal Ecology, Netherlands Institute
of Ecology (NIOO-KNAW), Wageningen 6708 PB, The Netherlands
| | - Mark Verschuuren
- Department
of Animal Ecology, Netherlands Institute
of Ecology (NIOO-KNAW), Wageningen 6708 PB, The Netherlands
| | - Kees van Oers
- Department
of Animal Ecology, Netherlands Institute
of Ecology (NIOO-KNAW), Wageningen 6708 PB, The Netherlands
| | - Silvia Espín
- Area
of Toxicology, Department of Socio-Sanitary Sciences, University of Murcia, Murcia 30003, Spain
- Department
of Biology, University of Turku, Turku 20500, Finland
| | - Pablo Sánchez-Virosta
- Area
of Toxicology, Department of Socio-Sanitary Sciences, University of Murcia, Murcia 30003, Spain
- Department
of Biology, University of Turku, Turku 20500, Finland
| | - Tapio Eeva
- Department
of Biology, University of Turku, Turku 20500, Finland
| | - Suvi Ruuskanen
- Department
of Biology, University of Turku, Turku 20500, Finland
- Department
of Biological and Environmental Science, University of Jyväskylä, Jyväskylä 40014, Finland
| |
Collapse
|
5
|
Barajas-Olmos FM, Ortiz-Sánchez E, Imaz-Rosshandler I, Córdova-Alarcón EJ, Martínez-Tovar A, Villanueva-Toledo J, Morales-Marín ME, Cruz-Colín JL, Rangel C, Orozco L, Centeno F. Analysis of the dynamic aberrant landscape of DNA methylation and gene expression during arsenic-induced cell transformation. Gene 2019; 711:143941. [PMID: 31242453 DOI: 10.1016/j.gene.2019.143941] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 05/30/2019] [Accepted: 06/19/2019] [Indexed: 02/07/2023]
Abstract
Inorganic arsenic is a well-known carcinogen associated with several types of cancer, but the mechanisms involved in arsenic-induced carcinogenesis are not fully understood. Recent evidence points to epigenetic dysregulation as an important mechanism in this process; however, the effects of epigenetic alterations in gene expression have not been explored in depth. Using microarray data and applying a multivariate clustering analysis in a Gaussian mixture model, we describe the alterations in DNA methylation around the promoter region and the impact on gene expression in HaCaT cells during the transformation process caused by chronic exposure to arsenic. Using this clustering approach, the genes were grouped according to their methylation and expression status in the epigenetic landscape, and the changes that occurred during the cellular transformation were identified adequately. Thus, we present a valuable method for identifying epigenomic dysregulation.
Collapse
Affiliation(s)
- Francisco M Barajas-Olmos
- Laboratorio de Inmunogenómica y Enfermedades Metabólicas, Instituto Nacional de Medicina Genómica, Ciudad de México, Mexico
| | - Elizabeth Ortiz-Sánchez
- Subdireccion de Investigación Básica, Instituto Nacional de Cancerología, Ciudad de México, Mexico
| | - Ivan Imaz-Rosshandler
- DAMTP, Centre for Mathematical Sciences, University of Cambridge, Cambridge CB3 OWA, UK
| | | | - Adolfo Martínez-Tovar
- Laboratorio de Biología Molecular, Servicio de Hematología, Hospital General de México "Dr. Eduardo Liceaga", Ciudad de México, Mexico
| | - Jairo Villanueva-Toledo
- Centro de Investigación en Salud "Dr. Jesús Kumate Rodríguez", Instituto Mexicano del Seguro Social, Mérida, Yucatán, Mexico; Cátedras CONACYT - Fundación IMSS AC, CONACYT, Ciudad de México, Mexico
| | - Mirna E Morales-Marín
- Laboratorio de Genómica de Enfermedades Psiquiátricas y Neurodegenerativas, Instituto Nacional de Medicina Genómica, Ciudad de México, Mexico
| | - José L Cruz-Colín
- Subdirección de Investigación Básica, Instituto Nacional de Medicina Genómica, Ciudad de México, Mexico
| | - Claudia Rangel
- Computational Genomics Consortium, Instituto Nacional de Medicina Genómica, Ciudad de México, Mexico
| | - Lorena Orozco
- Laboratorio de Inmunogenómica y Enfermedades Metabólicas, Instituto Nacional de Medicina Genómica, Ciudad de México, Mexico
| | - Federico Centeno
- Laboratorio de Inmunogenómica y Enfermedades Metabólicas, Instituto Nacional de Medicina Genómica, Ciudad de México, Mexico.
| |
Collapse
|
6
|
Huang N, Pei X, Lin W, Chiu JF, Tao T, Li G. DNA methylation of a non-CpG island promoter represses NQO1 expression in rat arsenic-transformed lung epithelial cells. Acta Biochim Biophys Sin (Shanghai) 2018; 50:733-739. [PMID: 29889218 DOI: 10.1093/abbs/gmy063] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Indexed: 02/05/2023] Open
Abstract
NAD(P)H:quinone oxidoreductase 1 (NQO1), a phase II flavoenzyme that catalyzes reduction reactions to protect cells against electrophiles and oxidants, is involved in tumorigenesis. Altered methylation of the NQO1 gene has been observed and is speculated to result in aberrant NQO1 expression in rat cells undergoing chemical carcinogenesis, although this has not been proven experimentally. In this study, we first investigated the potential epigenetic mechanisms underlying the phenomenon of NQO1 differential expression in individual subclones of rat arsenic-transformed lung epithelial cells (TLECs). NQO1 expression of TLEC subclones with or without 5-aza-2'-deoxycytidine (5-Aza-CdR) treatment was assessed by reverse transcriptase-polymerase chain reaction (RT-PCR), western blot analysis, and real-time PCR. Methylation status of the NQO1 promoter in TLEC subclones was analyzed by bisulfite sequencing. Transcriptional activity of NQO1 promoter in vitro methylated was determined by luciferase assay using a CpG-free luciferase reporter driven by the NQO1 promoter region (-435 to +229). We found that non-CpG island (non-CpGI) within the NQO1 promoter was hyper- or hypo-methylated in TLEC subclones and corresponded to low and high gene expressions, respectively. Following the treatment with 5-Aza-CdR, transcription of the NQO1 gene in the hypermethylated subclones was restored, accompanied by demethylation of the NQO1 promoter. In vitro promoter methylation almost completely silenced reporter activity in TLECs. These results indicate that DNA methylation of the non-CpGI promoter contributes to epigenetic silencing of NQO1 in rat TLECs.
Collapse
Affiliation(s)
- Ningyu Huang
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, China
| | - Xiaojuan Pei
- Department of Pathology, Shenzhen Hospital of Southern Medical University, Shenzhen, China
| | - Wenbo Lin
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, China
| | - Jen-Fu Chiu
- Department of Biochemistry, The Key Lab of Molecular Biology for High Cancer Incidence Coastal Chaoshan Area, Shantou University Medical College, Shantou, China
- School of Biomedical Sciences, LKS Faculty of Medicine, University of Hong Kong, Hong Kong, China
| | - Tao Tao
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, China
| | - Guanwu Li
- Department of Biochemistry, The Key Lab of Molecular Biology for High Cancer Incidence Coastal Chaoshan Area, Shantou University Medical College, Shantou, China
| |
Collapse
|
7
|
Zhou T, Niu W, Yuan Z, Guo S, Song Y, Di C, Xu X, Tan X, Yang L. ABCA1 Is Coordinated with ABCB1 in the Arsenic-Resistance of Human Cells. Appl Biochem Biotechnol 2018; 187:365-377. [PMID: 29951962 DOI: 10.1007/s12010-018-2800-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 05/30/2018] [Indexed: 11/30/2022]
Abstract
Arsenic is one of the most widespread global environmental toxicants associated with endemic poisoning. ATP-binding cassette (ABC) proteins are transmembrane channels that transport and dispose of lipids and metabolic products across the plasma membrane. The majority of ABC family members (including ABCB1 and ABCC1) are reported to play a role in the development of arsenic and drug resistance in mammals. Previously, we established a human arsenic-resistant ECV-304 (AsRE) cell line and identified ABCA1 as a novel arsenic resistance gene. In the current study, we further investigated the potential contribution of ABCA1, ABCB1, and ABCC1 to arsenic resistance through measurement of survival rates and arsenic accumulation in AsRE cells with RNA interference. The arsenic resistance capacity of ABCC1 was the strongest among the three genes, while those of ABCA1 and ABCB1 were similar. Double or triple gene knockdown of ABCA1, ABCB1, and ABCC1 via RNA interference led to a decrease significant in arsenic resistance when ABCA1/ABCB1 or ABCB1/ABCC1 were simultaneously silenced. Interestingly, no differences were evident between cells with ABCA1/ABCC1 and ABCC1 only knockdown. Our findings suggest that ABCA1 and ABCB1 proteins display similar arsenic resistance capabilities and possibly coordinate to promote arsenic resistance in AsRE cells.
Collapse
Affiliation(s)
- Tong Zhou
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang, People's Republic of China
| | - Wanqiang Niu
- School of Medicine, Hangzhou Normal University, Hangzhou, Zhejiang, People's Republic of China
| | - Zhen Yuan
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang, People's Republic of China
| | - Shuli Guo
- Ministry of Education Key Laboratory of Xinjiang Endemic and Ethnic Diseases, Shihezi University, Xinjiang, People's Republic of China
| | - Yang Song
- School of Medicine, Hangzhou Normal University, Hangzhou, Zhejiang, People's Republic of China
| | - Chunhong Di
- Affiliated Hospital, Hangzhou Normal University, Hangzhou, Zhejiang, People's Republic of China
| | - Xiaoling Xu
- School of Medicine, Hangzhou Normal University, Hangzhou, Zhejiang, People's Republic of China.
| | - Xiaohua Tan
- School of Medicine, Hangzhou Normal University, Hangzhou, Zhejiang, People's Republic of China.
| | - Lei Yang
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang, People's Republic of China. .,School of Medicine, Hangzhou Normal University, Hangzhou, Zhejiang, People's Republic of China. .,Ministry of Education Key Laboratory of Xinjiang Endemic and Ethnic Diseases, Shihezi University, Xinjiang, People's Republic of China.
| |
Collapse
|
8
|
Gonzalez-Cortes T, Recio-Vega R, Lantz RC, Chau BT. DNA methylation of extracellular matrix remodeling genes in children exposed to arsenic. Toxicol Appl Pharmacol 2017; 329:140-147. [PMID: 28579250 DOI: 10.1016/j.taap.2017.06.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Revised: 05/30/2017] [Accepted: 06/01/2017] [Indexed: 12/24/2022]
Abstract
Several novel mechanistic findings regarding to arsenic's pathogenesis has been reported and some of them suggest that the etiology of some arsenic induced diseases are due in part to heritable changes to the genome via epigenetic processes such as DNA methylation, histone maintenance, and mRNA expression. Recently, we reported that arsenic exposure during in utero and early life was associated with impairment in the lung function and abnormal receptor for advanced glycation endproducts (RAGE), matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) sputum levels. Based on our results and the reported arsenic impacts on DNA methylation, we designed this study in our cohort of children exposed in utero and early childhood to arsenic with the aim to associate DNA methylation of MMP9, TIMP1 and RAGE genes with its protein sputum levels and with urinary and toenail arsenic levels. The results disclosed hypermethylation in MMP9 promotor region in the most exposed children; and an increase in the RAGE sputum levels among children with the mid methylation level; there were also positive associations between MMP9 DNA methylation with arsenic toenail concentrations; RAGE DNA methylation with iAs, and %DMA; and finally between TIMP1 DNA methylation with the first arsenic methylation. A negative correlation between MMP9 sputum levels with its DNA methylation was registered. In conclusion, arsenic levels were positive associated with the DNA methylation of extracellular matrix remodeling genes;, which in turn could modifies the biological process in which they are involved causing or predisposing to lung diseases.
Collapse
Affiliation(s)
- Tania Gonzalez-Cortes
- Department of Environmental Health, Biomedical Research Center, School of Medicine, University of Coahuila, Torreon, Coahuila, Mexico
| | - Rogelio Recio-Vega
- Department of Environmental Health, Biomedical Research Center, School of Medicine, University of Coahuila, Torreon, Coahuila, Mexico.
| | - Robert Clark Lantz
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ, United States; Southwest Environmental Health Science Center, University of Arizona, Tucson, AZ, United States
| | - Binh T Chau
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ, United States
| |
Collapse
|
9
|
Holcomb N, Goswami M, Han SG, Scott T, D'Orazio J, Orren DK, Gairola CG, Mellon I. Inorganic arsenic inhibits the nucleotide excision repair pathway and reduces the expression of XPC. DNA Repair (Amst) 2017; 52:70-80. [PMID: 28237621 DOI: 10.1016/j.dnarep.2017.02.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Revised: 01/11/2017] [Accepted: 02/12/2017] [Indexed: 11/17/2022]
Abstract
Chronic exposure to arsenic, most often through contaminated drinking water, has been linked to several types of cancer in humans, including skin and lung cancer. However, the mechanisms underlying its role in causing cancer are not well understood. There is evidence that exposure to arsenic can enhance the carcinogenicity of UV light in inducing skin cancers and may enhance the carcinogenicity of tobacco smoke in inducing lung cancers. The nucleotide excision repair (NER) pathway removes different types of DNA damage including those produced by UV light and components of tobacco smoke. The aim of the present study was to investigate the effect of sodium arsenite on the NER pathway in human lung fibroblasts (IMR-90 cells) and primary mouse keratinocytes. To measure NER, we employed a slot-blot assay to quantify the introduction and removal of UV light-induced 6-4 photoproducts (6-4 PP) and cyclobutane pyrimidine dimers (CPDs). We find a concentration-dependent inhibition of the removal of 6-4 PPs and CPDs in both cell types treated with arsenite. Treatment of both cell types with arsenite resulted in a significant reduction in the abundance of XPC, a protein that is critical for DNA damage recognition in NER. The abundance of RNA expressed from several key NER genes was also significantly reduced by treatment of IMR-90 cells with arsenite. Finally, treatment of IMR-90 cells with MG-132 abrogated the reduction in XPC protein, suggesting an involvement of the proteasome in the reduction of XPC protein produced by treatment of cells with arsenic. The inhibition of NER by arsenic may reflect one mechanism underlying the role of arsenic exposure in enhancing cigarette smoke-induced lung carcinogenesis and UV light-induced skin cancer, and it may provide some insights into the emergence of arsenic trioxide as a chemotherapeutic agent.
Collapse
Affiliation(s)
- Nathaniel Holcomb
- Department of Toxicology and Cancer Biology, The Markey Cancer Center, University of Kentucky, Lexington, KY, United States
| | - Mamta Goswami
- Department of Toxicology and Cancer Biology, The Markey Cancer Center, University of Kentucky, Lexington, KY, United States
| | - Sung Gu Han
- Toxicology Laboratory, Department of Food Science and Biotechnology of Animal Resources, College of Animal Bioscience and Technology, Konkuk University, Seoul 05029, Republic of Korea
| | - Tim Scott
- Department of Toxicology and Cancer Biology, The Markey Cancer Center, University of Kentucky, Lexington, KY, United States
| | - John D'Orazio
- Department of Toxicology and Cancer Biology, The Markey Cancer Center, University of Kentucky, Lexington, KY, United States
| | - David K Orren
- Department of Toxicology and Cancer Biology, The Markey Cancer Center, University of Kentucky, Lexington, KY, United States
| | - C Gary Gairola
- Department of Toxicology and Cancer Biology, The Markey Cancer Center, University of Kentucky, Lexington, KY, United States
| | - Isabel Mellon
- Department of Toxicology and Cancer Biology, The Markey Cancer Center, University of Kentucky, Lexington, KY, United States.
| |
Collapse
|
10
|
Landrigan PJ, Wright RO, Cordero JF, Eaton DL, Goldstein BD, Hennig B, Maier RM, Ozonoff DM, Smith MT, Tukey RH. The NIEHS Superfund Research Program: 25 Years of Translational Research for Public Health. ENVIRONMENTAL HEALTH PERSPECTIVES 2015; 123:909-18. [PMID: 25978799 PMCID: PMC4590764 DOI: 10.1289/ehp.1409247] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Accepted: 05/12/2015] [Indexed: 05/23/2023]
Abstract
BACKGROUND The Superfund Research Program (SRP) is an academically based, multidisciplinary, translational research program that for 25 years has sought scientific solutions to health and environmental problems associated with hazardous waste sites. SRP is coordinated by the National Institute of Environmental Health Sciences (NIEHS). It supports multi-project grants, undergraduate and postdoctoral training programs, individual research grants, and Small Business Innovation Research (SBIR) and Technology Transfer Research (STTR) grants. RESULTS SRP has had many successes: discovery of arsenic's toxicity to the developing human central nervous system; documentation of benzene toxicity to hematologic progenitor cells in human bone marrow; development of novel analytic techniques such as the luciferase expression assay and laser fragmentation fluorescence spectroscopy; demonstration that PCBs can cause developmental neurotoxicity at low levels and alter the genomic characteristics of sentinel animals; elucidation of the neurodevelopmental toxicity of organophosphate insecticides; documentation of links between antimicrobial agents and alterations in hormone response; discovery of biological mechanisms through which environmental chemicals may contribute to obesity, atherosclerosis, diabetes, and cancer; tracking the health and environmental effects of the attacks on the World Trade Center and Hurricane Katrina; and development of novel biological and engineering techniques to facilitate more efficient and lower-cost remediation of hazardous waste sites. CONCLUSION SRP must continue to address the legacy of hazardous waste in the United States, respond to new issues caused by rapid advances in technology, and train the next generation of leaders in environmental health science while recognizing that most of the world's worst toxic hot spots are now located in low- and middle-income countries.
Collapse
|
11
|
Environmental pollution and DNA methylation: carcinogenesis, clinical significance, and practical applications. Front Med 2015; 9:261-74. [PMID: 26290283 DOI: 10.1007/s11684-015-0406-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Accepted: 05/12/2015] [Indexed: 01/25/2023]
Abstract
Environmental pollution is one of the main causes of human cancer. Exposures to environmental carcinogens result in genetic and epigenetic alterations which induce cell transformation. Epigenetic changes caused by environmental pollution play important roles in the development and progression of environmental pollution-related cancers. Studies on DNA methylation are among the earliest and most conducted epigenetic research linked to cancer. In this review, the roles of DNA methylation in carcinogenesis and their significance in clinical medicine were summarized, and the effects of environmental pollutants, particularly air pollutants, on DNA methylation were introduced. Furthermore, prospective applications of DNA methylation to environmental pollution detection and cancer prevention were discussed.
Collapse
|
12
|
Limaye S, Salvi S. Obesity and asthma: the role of environmental pollutants. Immunol Allergy Clin North Am 2014; 34:839-55. [PMID: 25282295 DOI: 10.1016/j.iac.2014.07.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Air pollution is a well-known risk for lung diseases, including asthma. Growing evidences suggesting air pollution as a novel risk factor for the development of obesity. Several Epidemiological studies have ascertained an association between various ambient and indoor air pollutants and obesity by medium of endocrine disruptive chemicals that can disrupt the normal development and homeostatic controls over adipogenesis and energy balance and induce obesity. Several obesity-induced mechanisms have been proposed that increases this vulnerability of obese individuals to harmful effects of air pollution rendering them more susceptible to developing air-pollution driven incident asthma or worsening of already existing asthma.
Collapse
Affiliation(s)
- Sneha Limaye
- Chest Research Foundation, Marigold Premises, Survey No 15, Vadgaonsheri, Kalyaninagar, Pune 411 014, India.
| | - Sundeep Salvi
- Chest Research Foundation, Marigold Premises, Survey No 15, Vadgaonsheri, Kalyaninagar, Pune 411 014, India
| |
Collapse
|
13
|
Global DNA hypomethylation: A potential mechanism in King pigeon nerve tissue damage induced by avermectin. Chem Biol Interact 2014; 219:113-22. [DOI: 10.1016/j.cbi.2014.05.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Revised: 05/03/2014] [Accepted: 05/12/2014] [Indexed: 12/15/2022]
|
14
|
Ray PD, Yosim A, Fry RC. Incorporating epigenetic data into the risk assessment process for the toxic metals arsenic, cadmium, chromium, lead, and mercury: strategies and challenges. Front Genet 2014; 5:201. [PMID: 25076963 PMCID: PMC4100550 DOI: 10.3389/fgene.2014.00201] [Citation(s) in RCA: 106] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Accepted: 06/16/2014] [Indexed: 12/24/2022] Open
Abstract
Exposure to toxic metals poses a serious human health hazard based on ubiquitous environmental presence, the extent of exposure, and the toxicity and disease states associated with exposure. This global health issue warrants accurate and reliable models derived from the risk assessment process to predict disease risk in populations. There has been considerable interest recently in the impact of environmental toxicants such as toxic metals on the epigenome. Epigenetic modifications are alterations to an individual's genome without a change in the DNA sequence, and include, but are not limited to, three commonly studied alterations: DNA methylation, histone modification, and non-coding RNA expression. Given the role of epigenetic alterations in regulating gene and thus protein expression, there is the potential for the integration of toxic metal-induced epigenetic alterations as informative factors in the risk assessment process. In the present review, epigenetic alterations induced by five high priority toxic metals/metalloids are prioritized for analysis and their possible inclusion into the risk assessment process is discussed.
Collapse
Affiliation(s)
- Paul D. Ray
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North CarolinaChapel Hill, NC, USA
- Curriculum in Toxicology, School of Medicine, University of North CarolinaChapel Hill, NC, USA
| | - Andrew Yosim
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North CarolinaChapel Hill, NC, USA
| | - Rebecca C. Fry
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North CarolinaChapel Hill, NC, USA
- Curriculum in Toxicology, School of Medicine, University of North CarolinaChapel Hill, NC, USA
| |
Collapse
|
15
|
Unterberg M, Leffers L, Hübner F, Humpf HU, Lepikhov K, Walter J, Ebert F, Schwerdtle T. Toxicity of arsenite and thio-DMAV after long-term (21 days) incubation of human urothelial cells: cytotoxicity, genotoxicity and epigenetics. Toxicol Res (Camb) 2014. [DOI: 10.1039/c4tx00036f] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
This study aims to further mechanistically understand toxic modes of action after chronic arsenic species exposure.
Collapse
Affiliation(s)
- Marlies Unterberg
- Graduate School of Chemistry
- WWU Muenster
- 48149 Muenster, Germany
- Institute of Nutritional Sciences
- University of Potsdam
| | - Larissa Leffers
- Graduate School of Chemistry
- WWU Muenster
- 48149 Muenster, Germany
| | - Florian Hübner
- Institute of Food Chemistry
- WWU Muenster
- 48149 Muenster, Germany
| | - Hans-Ulrich Humpf
- Graduate School of Chemistry
- WWU Muenster
- 48149 Muenster, Germany
- Institute of Food Chemistry
- WWU Muenster
| | - Konstantin Lepikhov
- Department of Genetics/Epigenetics
- Campus Saarbruecken
- Saarland University
- 66123 Saarbruecken, Germany
| | - Jörn Walter
- Department of Genetics/Epigenetics
- Campus Saarbruecken
- Saarland University
- 66123 Saarbruecken, Germany
| | - Franziska Ebert
- Institute of Nutritional Sciences
- University of Potsdam
- 14558 Nuthetal, Germany
| | - Tanja Schwerdtle
- Graduate School of Chemistry
- WWU Muenster
- 48149 Muenster, Germany
- Institute of Nutritional Sciences
- University of Potsdam
| |
Collapse
|
16
|
Gribble MO, Tang WY, Shang Y, Pollak J, Umans JG, Francesconi KA, Goessler W, Silbergeld EK, Guallar E, Cole SA, Fallin MD, Navas-Acien A. Differential methylation of the arsenic (III) methyltransferase promoter according to arsenic exposure. Arch Toxicol 2013; 88:275-82. [PMID: 24154821 DOI: 10.1007/s00204-013-1146-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Accepted: 10/07/2013] [Indexed: 10/26/2022]
Abstract
Inorganic arsenic is methylated in the body by arsenic (III) methyltransferase (AS3MT). Arsenic methylation is thought to play a role in arsenic-related epigenetic phenomena, including aberrant DNA and histone methylation. However, it is unclear whether the promoter of the AS3MT gene, which codes for AS3MT, is differentially methylated as a function of arsenic exposure. In this study, we evaluated AS3MT promoter methylation according to exposure, assessed by urinary arsenic excretion in a stratified random sample of 48 participants from the Strong Heart Study who had urine arsenic measured at baseline and DNA available from 1989 to 1991 and 1998-1999. For this study, all data are from the 1989-1991 visit. We measured AS3MT promoter methylation at its 48 CpG loci by bisulphite sequencing. We compared mean % methylation at each CpG locus by arsenic exposure group using linear regression adjusted for study centre, age and sex. A hypomethylated region in the AS3MT promoter was associated with higher arsenic exposure. In vitro, arsenic induced AS3MT promoter hypomethylation, and it increased AS3MT expression in human peripheral blood mononuclear cells. These findings may suggest that arsenic exposure influences the epigenetic regulation of a major arsenic metabolism gene.
Collapse
Affiliation(s)
- Matthew O Gribble
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Severson PL, Tokar EJ, Vrba L, Waalkes MP, Futscher BW. Coordinate H3K9 and DNA methylation silencing of ZNFs in toxicant-induced malignant transformation. Epigenetics 2013; 8:1080-8. [PMID: 23974009 PMCID: PMC3891689 DOI: 10.4161/epi.25926] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Genome-wide disruption of the epigenetic code is a hallmark of malignancy that encompasses many distinct, highly interactive modifications. Delineating the aberrant epigenome produced during toxicant-mediated malignant transformation will help identify the underlying epigenetic drivers of environmental toxicant-induced carcinogenesis. Gene promoter DNA methylation and gene expression profiling of arsenite-transformed prostate epithelial cells showed a negative correlation between gene expression changes and DNA methylation changes; however, less than 10% of the genes with increased promoter methylation were downregulated. Studies described herein confirm that a majority of the DNA hypermethylation events occur at H3K27me3 marked genes that were already transcriptionally repressed. In contrast to aberrant DNA methylation targeting H3K27me3 pre-marked silent genes, we found that actively expressed C2H2 zinc finger genes (ZNFs) marked with H3K9me3 on their 3′ ends, were the favored targets of DNA methylation linked gene silencing. DNA methylation coupled, H3K9me3 mediated gene silencing of ZNF genes was widespread, occurring at individual ZNF genes on multiple chromosomes and across ZNF gene family clusters. At ZNF gene promoters, H3K9me3 and DNA hypermethylation replaced H3K4me3, resulting in a widespread downregulation of ZNF gene expression, which accounted for 8% of all the downregulated genes in the arsenical-transformed cells. In summary, these studies associate toxicant exposure with widespread silencing of ZNF genes by DNA hypermethylation-linked H3K9me3 spreading, further implicating epigenetic dysfunction as a driver of toxicant associated carcinogenesis.
Collapse
Affiliation(s)
- Paul L Severson
- Department of Pharmacology and Toxicology; College of Pharmacy; University of Arizona; Tucson, AZ USA
| | - Erik J Tokar
- National Toxicology Program Laboratory; National Institute of Environmental Health Sciences; Research Triangle Park, NC USA
| | - Lukas Vrba
- University of Arizona Cancer Center; Tucson, AZ USA
| | - Michael P Waalkes
- National Toxicology Program Laboratory; National Institute of Environmental Health Sciences; Research Triangle Park, NC USA
| | - Bernard W Futscher
- Department of Pharmacology and Toxicology; College of Pharmacy; University of Arizona; Tucson, AZ USA; University of Arizona Cancer Center; Tucson, AZ USA
| |
Collapse
|
18
|
Johnen G, Rozynek P, von der Gathen Y, Bryk O, Zdrenka R, Johannes C, Weber DG, Igwilo-Okuefuna OB, Raiko I, Hippler J, Brüning T, Dopp E. Cross-contamination of a UROtsa stock with T24 cells--molecular comparison of different cell lines and stocks. PLoS One 2013; 8:e64139. [PMID: 23691160 PMCID: PMC3656924 DOI: 10.1371/journal.pone.0064139] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Accepted: 04/08/2013] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND UROtsa is an authentic, immortalized human urothelial cell line that is used to study the effects of metals and other toxic substances, mostly in the context of bladder cancer carcinogenesis. Unusual properties on the molecular level of a provided UROtsa cell line stock prompted us to verify its identity. METHODS UROtsa cell line stocks from different sources were tested on several molecular levels and compared with other cell lines. MicroRNA and mRNA expression was determined by Real-Time PCR. Chromosome numbers were checked and PCR of different regions of the large T-antigen was performed. DNA methylation of RARB, PGR, RASSF1, CDH1, FHIT, ESR1, C1QTNF6, PTGS2, SOCS3, MGMT, and LINE1 was analyzed by pyrosequencing and compared with results from the cell lines RT4, T24, HeLa, BEAS-2B, and HepG2. Finally, short tandem repeat (STR) profiling was applied. RESULTS All tested UROtsa cell line stocks lacked large T-antigen. STR analysis unequivocally identified our main UROtsa stock as the bladder cancer cell line T24, which was different from two authentic UROtsa stocks that served as controls. Analysis of DNA methylation patterns and RNA expression confirmed their differences. Methylation pattern and mRNA expression of the contaminating T24 cell line showed moderate changes even after long-term culture of up to 56 weeks, whereas miRNAs and chromosome numbers varied markedly. CONCLUSIONS It is important to check the identity of cell lines, especially those that are not distributed by major cell banks. However, for some cell lines STR profiles are not available. Therefore, new cell lines should either be submitted to cell banks or at least their STR profile determined and published as part of their initial characterization. Our results should help to improve the identification of UROtsa and other cells on different molecular levels and provide information on the use of urothelial cells for long-term experiments.
Collapse
Affiliation(s)
- Georg Johnen
- Institute for Prevention and Occupational Medicine of the German Social Accident Insurance, Institute of the Ruhr University Bochum, IPA, Bochum, Germany.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Futscher BW. Epigenetic changes during cell transformation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 754:179-94. [PMID: 22956502 DOI: 10.1007/978-1-4419-9967-2_9] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Malignant cancer emerges from normal healthy cells in a multistep -process that involves both genetic and epigenetic lesions. Both genetic and environmental inputs participate in driving the epigenetic changes that occur during human carcinogenesis. The pathologic changes seen in DNA methylation and histone posttranslational modifications are complex, deeply intertwined, and act in concert to produce malignant transformation. To better understand the causes and consequences of the pathoepigenetic changes in cancer formation, a variety of experimentally tractable human cell line model systems that accurately reflect the molecular alterations seen in the clinical disease have been developed. Results from studies using these cell line model systems suggest that early critical epigenetic events occur in a stepwise fashion prior to cell immortalization. These epigenetic steps coincide with the cell's transition through well-defined cell proliferation barriers of stasis and telomere dysfunction. Following cell immortalization, stressors, such as environmental toxicants, can induce malignant transformation in a process in which the epigenetic changes occur in a smoother progressive fashion, in contrast to the stark stepwise epigenetic changes seen prior to cell immortalization. It is hoped that developing a clearer understanding of the identity, timing, and consequences of these epigenetic lesions will prove useful in future clinical applications that range from early disease detection to therapeutic intervention in malignant cancer.
Collapse
Affiliation(s)
- Bernard W Futscher
- Department of Pharmacology and Toxicology, College of Pharmacy and The University of Arizona Cancer Center, The University of Arizona, Tucson, AZ 85724-5024, USA.
| |
Collapse
|
20
|
Latham KE, Sapienza C, Engel N. The epigenetic lorax: gene-environment interactions in human health. Epigenomics 2012; 4:383-402. [PMID: 22920179 DOI: 10.2217/epi.12.31] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Over the last decade, we have witnessed an explosion of information on genetic factors underlying common human diseases and disorders. This 'human genomics' information revolution has occurred as a backdrop to a rapid increase in the rates of many human disorders and diseases. For example, obesity, Type 2 diabetes, asthma, autism spectrum disorder and attention deficit hyperactivity disorder have increased at rates that cannot be due to changes in the genetic structure of the population, and are difficult to ascribe to changes in diagnostic criteria or ascertainment. A likely cause of the increased incidence of these disorders is increased exposure to environmental factors that modify gene function. Many environmental factors that have epidemiological association with common human disorders are likely to exert their effects through epigenetic alterations. This general mechanism of gene-environment interaction poses special challenges for individuals, educators, scientists and public policy makers in defining, monitoring and mitigating exposures.
Collapse
Affiliation(s)
- Keith E Latham
- Fels Institute for Cancer Research & Molecular Biology, Temple University School of Medicine, Philadelphia, PA 19140, USA.
| | | | | |
Collapse
|
21
|
Severson PL, Tokar EJ, Vrba L, Waalkes MP, Futscher BW. Agglomerates of aberrant DNA methylation are associated with toxicant-induced malignant transformation. Epigenetics 2012; 7:1238-48. [PMID: 22976526 PMCID: PMC3499325 DOI: 10.4161/epi.22163] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Epigenetic dysfunction is a known contributor in carcinogenesis, and is emerging as a mechanism involved in toxicant-induced malignant transformation for environmental carcinogens such as arsenicals or cadmium. In addition to aberrant DNA methylation of single genes, another manifestation of epigenetic dysfunction in cancer is agglomerative DNA methylation, which can participate in long-range epigenetic silencing that targets many neighboring genes and has been shown to occur in several types of clinical cancers. Using in vitro model systems of toxicant-induced malignant transformation, we found hundreds of aberrant DNA methylation events that emerge during malignant transformation, some of which occur in an agglomerative fashion. In an arsenite-transformed prostate epithelial cell line, the protocadherin (PCDH), HOXC and HOXD gene family clusters are targeted for agglomerative DNA methylation. The agglomerative DNA methylation changes induced by arsenicals appear to be common and clinically relevant events, since they occur in other human cancer cell lines and models of malignant transformation, as well as clinical cancer specimens. Aberrant DNA methylation in general occurred more often within histone H3 lysine-27 trimethylation stem cell domains. We found a striking association between enrichment of histone H3 lysine-9 trimethylation stem cell domains and toxicant-induced agglomerative DNA methylation, suggesting these epigenetic modifications may become aberrantly linked during malignant transformation. In summary, we found an association between toxicant-induced malignant transformation and agglomerative DNA methylation, which lends further support to the hypothesis that epigenetic dysfunction plays an important role in toxicant-induced malignant transformation.
Collapse
Affiliation(s)
- Paul L Severson
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, Tucson, AZ, USA
| | | | | | | | | |
Collapse
|
22
|
Medeiros M, Zheng X, Novak P, Wnek SM, Chyan V, Escudero-Lourdes C, Gandolfi AJ. Global gene expression changes in human urothelial cells exposed to low-level monomethylarsonous acid. Toxicology 2011; 291:102-12. [PMID: 22108045 DOI: 10.1016/j.tox.2011.11.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2011] [Revised: 10/13/2011] [Accepted: 11/08/2011] [Indexed: 02/06/2023]
Abstract
Bladder cancer has been associated with chronic arsenic exposure. Monomethylarsonous acid [MMA(III)] is a metabolite of inorganic arsenic and has been shown to transform an immortalized urothelial cell line (UROtsa) at concentrations 20-fold less than arsenite. MMA(III) was used as a model arsenical to examine the mechanisms of arsenical-induced transformation of urothelium. A microarray analysis was performed to assess the transcriptional changes in UROtsa during the critical window of chronic 50nM MMA(III) exposure that leads to transformation at 3 months of exposure. The analysis revealed only minor changes in gene expression at 1 and 2 months of exposure, contrasting with substantial changes observed at 3 months of exposure. The gene expression changes at 3 months were analyzed showing distinct alterations in biological processes and pathways such as a response to oxidative stress, enhanced cell proliferation, anti-apoptosis, MAPK signaling, as well as inflammation. Twelve genes selected as markers of these particular biological processes were used to validate the microarray and these genes showed a time-dependent changes at 1 and 2 months of exposure, with the most substantial changes occurring at 3 months of exposure. These results indicate that there is a strong association between the acquired phenotypic changes that occur with chronic MMA(III) exposure and the observed gene expression patterns that are indicative of a malignant transformation. Although the substantial changes that occur at 3 months of exposure may be a consequence of transformation, there are common occurrences of altered biological processes between the first 2 months of exposure and the third, which may be pivotal in driving transformation.
Collapse
Affiliation(s)
- Matthew Medeiros
- Department of Pharmacology and Toxicology, University of Arizona, Tucson, AZ 85721, United States.
| | | | | | | | | | | | | |
Collapse
|
23
|
States JC, Barchowsky A, Cartwright IL, Reichard JF, Futscher BW, Lantz RC. Arsenic toxicology: translating between experimental models and human pathology. ENVIRONMENTAL HEALTH PERSPECTIVES 2011; 119:1356-63. [PMID: 21684831 PMCID: PMC3230447 DOI: 10.1289/ehp.1103441] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2011] [Accepted: 06/17/2011] [Indexed: 05/21/2023]
Abstract
BACKGROUND Chronic arsenic exposure is a worldwide health problem. How arsenic exposure promotes a variety of diseases is poorly understood, and specific relationships between experimental and human exposures are not established. We propose phenotypic anchoring as a means to unify experimental observations and disease outcomes. OBJECTIVES We examined the use of phenotypic anchors to translate experimental data to human pathology and investigated research needs for which phenotypic anchors need to be developed. METHODS During a workshop, we discussed experimental systems investigating arsenic dose/exposure and phenotypic expression relationships and human disease responses to chronic arsenic exposure and identified knowledge gaps. In a literature review, we identified areas where data exist to support phenotypic anchoring of experimental results to pathologies from specific human exposures. DISCUSSION Disease outcome is likely dependent on cell-type-specific responses and interaction with individual genetics, other toxicants, and infectious agents. Potential phenotypic anchors include target tissue dosimetry, gene expression and epigenetic profiles, and tissue biomarkers. CONCLUSIONS Translation to human populations requires more extensive profiling of human samples along with high-quality dosimetry. Anchoring results by gene expression and epigenetic profiling has great promise for data unification. Genetic predisposition of individuals affects disease outcome. Interactions with infectious agents, particularly viruses, may explain some species-specific differences between human pathologies and experimental animal pathologies. Invertebrate systems amenable to genetic manipulation offer potential for elaborating impacts of specific biochemical pathways. Anchoring experimental results to specific human exposures will accelerate understanding of mechanisms of arsenic-induced human disease.
Collapse
Affiliation(s)
- J Christopher States
- Department of Pharmacology and Toxicology, University of Louisville, Louisville, Kentucky, USA.
| | | | | | | | | | | |
Collapse
|
24
|
Santoyo MM, Flores CR, Torres AL, Wrobel K, Wrobel K. Global DNA methylation in earthworms: a candidate biomarker of epigenetic risks related to the presence of metals/metalloids in terrestrial environments. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2011; 159:2387-92. [PMID: 21782299 DOI: 10.1016/j.envpol.2011.06.041] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2011] [Revised: 06/28/2011] [Accepted: 06/30/2011] [Indexed: 05/13/2023]
Abstract
In this work, possible relationships between global DNA methylation and metal/metalloid concentrations in earthworms have been explored. Direct correlation was observed between soil and tissue As, Se, Sb, Zn, Cu, Mn, Ag, Co, Hg, Pb (p< 0.05). Speciation results obtained for As and Hg hint at the capability of earthworms for conversion of inorganic element forms present in soil to methylated species. Inverse correlation was observed between the percentage of methylated DNA cytosines and total tissue As, As + Hg, As + Hg + Se + Sb (β = -0.8456, p = 0.071; β = -0.9406, p = 0.017; β = -0.9526, p = 0.012 respectively), as well as inorganic As + Hg (β = -0.8807, p = 0.049). It was concluded that earthworms would be particularly helpful as bioindicators of elements undergoing in vivo methylation and might also be used to assess the related risk of epigenetic changes in DNA methylation.
Collapse
Affiliation(s)
- María Maldonado Santoyo
- Department of Chemistry, University of Guanajuato, L de Retana N° 5, 36000 Guanajuato, Mexico
| | | | | | | | | |
Collapse
|
25
|
Cyr AR, Domann FE. The redox basis of epigenetic modifications: from mechanisms to functional consequences. Antioxid Redox Signal 2011; 15:551-89. [PMID: 20919933 PMCID: PMC3118659 DOI: 10.1089/ars.2010.3492] [Citation(s) in RCA: 194] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Epigenetic modifications represent mechanisms by which cells may effectively translate multiple signaling inputs into phenotypic outputs. Recent research is revealing that redox metabolism is an increasingly important determinant of epigenetic control that may have significant ramifications in both human health and disease. Numerous characterized epigenetic marks, including histone methylation, acetylation, and ADP-ribosylation, as well as DNA methylation, have direct linkages to central metabolism through critical redox intermediates such as NAD(+), S-adenosyl methionine, and 2-oxoglutarate. Fluctuations in these intermediates caused by both normal and pathologic stimuli may thus have direct effects on epigenetic signaling that lead to measurable changes in gene expression. In this comprehensive review, we present surveys of both metabolism-sensitive epigenetic enzymes and the metabolic processes that may play a role in their regulation. To close, we provide a series of clinically relevant illustrations of the communication between metabolism and epigenetics in the pathogenesis of cardiovascular disease, Alzheimer disease, cancer, and environmental toxicity. We anticipate that the regulatory mechanisms described herein will play an increasingly large role in our understanding of human health and disease as epigenetics research progresses.
Collapse
Affiliation(s)
- Anthony R Cyr
- Free Radical and Radiation Biology Program, Department of Radiation Oncology, Carver College of Medicine, The University of Iowa, Iowa City, Iowa 52242-1181, USA
| | | |
Collapse
|
26
|
Vandegehuchte MB, Janssen CR. Epigenetics and its implications for ecotoxicology. ECOTOXICOLOGY (LONDON, ENGLAND) 2011; 20:607-624. [PMID: 21424724 DOI: 10.1007/s10646-011-0634-0] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/05/2011] [Indexed: 05/30/2023]
Abstract
Epigenetics is the study of mitotically or meiotically heritable changes in gene function that occur without a change in the DNA sequence. Interestingly, epigenetic changes can be triggered by environmental factors. Environmental exposure to e.g. metals, persistent organic pollutants or endocrine disrupting chemicals has been shown to modulate epigenetic marks, not only in mammalian cells or rodents, but also in environmentally relevant species such as fish or water fleas. The associated changes in gene expression often lead to modifications in the affected organism's phenotype. Epigenetic changes can in some cases be transferred to subsequent generations, even when these generations are no longer exposed to the external factor which induced the epigenetic change, as observed in a study with fungicide exposed rats. The possibility of this phenomenon in other species was demonstrated in water fleas exposed to the epigenetic drug 5-azacytidine. This way, populations can experience the effects of their ancestors' exposure to chemicals, which has implications for environmental risk assessment. More basic research is needed to assess the potential phenotypic and population-level effects of epigenetic modifications in different species and to evaluate the persistence of chemical exposure-induced epigenetic effects in multiple subsequent generations.
Collapse
Affiliation(s)
- Michiel B Vandegehuchte
- Laboratory of Environmental Toxicology and Aquatic Ecology, Ghent University (UGent), Jozef Plateaustraat 22, 9000 Ghent, Belgium.
| | | |
Collapse
|
27
|
Tokar EJ, Qu W, Waalkes MP. Arsenic, stem cells, and the developmental basis of adult cancer. Toxicol Sci 2011; 120 Suppl 1:S192-203. [PMID: 21071725 PMCID: PMC3043086 DOI: 10.1093/toxsci/kfq342] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2010] [Accepted: 11/08/2010] [Indexed: 12/18/2022] Open
Abstract
That chemical insults or nutritive changes during in utero and/or postnatal life can emerge as diseases much later in life are now being accepted as a recurring phenomenon. In this regard, inorganic arsenic is a multisite human carcinogen found at high levels in the drinking water of millions of people, although it has been difficult until recently to produce tumors in rodents with this metalloid. A mouse transplacental model has been developed where maternal exposure to inorganic arsenic either acts as a complete carcinogen or enhances carcinogenic response to other agents given subsequently in the offspring, producing tumors during adulthood. Similarly, human data now have emerged showing that arsenic exposure during the in utero period and/or in early life is associated with cancer in adulthood. The mouse arsenic transplacental model produces tumors or enhances response to other agents in multiple strains and tissues, including sites concordant with human targets of arsenic carcinogenesis. It is now believed that cancer often is a stem cell (SC)-based disease, and there is no reason to think cancer induced by developmental chemical exposure is any different. Indeed, arsenic impacts human SC population dynamics in vitro by blocking exit into differentiation pathways and whereby creating more key targets for transformation. In fact, during in vitro malignant transformation, arsenic causes a remarkable survival selection of SCs, creating a marked overabundance of cancer SCs (CSCs) compared with other carcinogens once a cancer phenotype is obtained. In addition, skin cancers produced following in utero arsenic exposure in mice are highly enriched in CSCs. Thus, arsenic impacts key, long-lived SC populations as critical targets to cause or facilitate later oncogenic events in adulthood as a possible mechanism of developmental basis of adult disease.
Collapse
Affiliation(s)
| | | | - Michael P. Waalkes
- National Toxicology Program Laboratories, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina
| |
Collapse
|
28
|
Ren X, McHale CM, Skibola CF, Smith AH, Smith MT, Zhang L. An emerging role for epigenetic dysregulation in arsenic toxicity and carcinogenesis. ENVIRONMENTAL HEALTH PERSPECTIVES 2011; 119:11-9. [PMID: 20682481 PMCID: PMC3018488 DOI: 10.1289/ehp.1002114] [Citation(s) in RCA: 172] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2010] [Accepted: 08/02/2010] [Indexed: 05/08/2023]
Abstract
BACKGROUND Exposure to arsenic, an established human carcinogen, through consumption of highly contaminated drinking water is a worldwide public health concern. Several mechanisms by which arsenical compounds induce tumorigenesis have been proposed, including oxidative stress, genotoxic damage, and chromosomal abnormalities. Recent studies have suggested that epigenetic mechanisms may also mediate toxicity and carcinogenicity resulting from arsenic exposure. OBJECTIVE We examined the evidence supporting the roles of the three major epigenetic mechanisms-DNA methylation, histone modification, and microRNA (miRNA) expression-in arsenic toxicity and, in particular, carcinogenicity. We also investigated future research directions necessary to clarify epigenetic and other mechanisms in humans. DATA SOURCES AND SYNTHESIS We conducted a PubMed search of arsenic exposure and epigenetic modification through April 2010 and summarized the in vitro and in vivo research findings, from both our group and others, on arsenic-associated epigenetic alteration and its potential role in toxicity and carcinogenicity. CONCLUSIONS Arsenic exposure has been shown to alter methylation levels of both global DNA and gene promoters; histone acetylation, methylation, and phosphorylation; and miRNA expression, in studies analyzing mainly a limited number of epigenetic end points. Systematic epigenomic studies in human populations exposed to arsenic or in patients with arsenic-associated cancer have not yet been performed. Such studies would help to elucidate the relationship between arsenic exposure, epigenetic dysregulation, and carcinogenesis and are becoming feasible because of recent technological advancements.
Collapse
Affiliation(s)
- Xuefeng Ren
- Division of Environmental Health Sciences, School of Public Health, University of California–Berkeley, Berkeley, California 94720, USA.
| | | | | | | | | | | |
Collapse
|
29
|
Guerrero-Preston R, Goldman LR, Brebi-Mieville P, Ili-Gangas C, Lebron C, Witter FR, Apelberg BJ, Hernández-Roystacher M, Jaffe A, Halden RU, Sidransky D. Global DNA hypomethylation is associated with in utero exposure to cotinine and perfluorinated alkyl compounds. Epigenetics 2010; 5:539-46. [PMID: 20523118 DOI: 10.4161/epi.5.6.12378] [Citation(s) in RCA: 154] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Environmental exposures in-utero may alter the epigenome, thus impacting chromosomal stability and gene expression. We hypothesized that in utero exposures to maternal smoking and perfluoroalkyl compounds (PFCs) are associated with global DNA hypomethylation in umbilical cord serum. Our objective was to determine if global DNA methylation could be used as a biomarker of in utero exposures to maternal smoking and PFCs. Using an ELISA-based method, global DNA methylation was quantified in umbilical cord serum from 30 newborns with high (> 10 ng/ml, mean 123.8 ng/ml), low (range 1-10 ng/ml, mean 1.6 ng/ml) and very low (< 1 ng/ml, mean 0.06 ng/ml) cord serum cotinine levels. Y chromosome analysis was performed to rule out maternal DNA cross-contamination. Cord serum global DNA methylation showed an inverse dose response to serum cotinine levels (p< 0.001). Global DNA methylation levels in cord blood were the lowest among newborns with smoking mothers (mean=15.04%; 95% CI, 8.4, 21.7) when compared to babies of mothers who were second-hand smokers (21.1%; 95% CI, 16.6, 25.5) and non-smokers (mean=29.2%; 95% CI, 20.1, 38.1). Global DNA methylation was inversely correlated with serum PFOA (r= -0.72, p < 0.01) but not PFOS levels. Serum Y chromosome analyses did not detect maternal DNA cross-contamination. This study supports the use of global DNA methylation status as a biomarker of in utero exposure to cigarette smoke and PFCs.
Collapse
Affiliation(s)
- Rafael Guerrero-Preston
- Otolaryngology Department, Bloomberg School of Public Health, The Johns Hopkins University, Baltimore, MD, USA.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Boellmann F, Zhang L, Clewell HJ, Schroth GP, Kenyon EM, Andersen ME, Thomas RS. Genome-wide Analysis of DNA Methylation and Gene Expression Changes in the Mouse Lung following Subchronic Arsenate Exposure. Toxicol Sci 2010; 117:404-17. [DOI: 10.1093/toxsci/kfq225] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
|
31
|
Druwe IL, Vaillancourt RR. Influence of arsenate and arsenite on signal transduction pathways: an update. Arch Toxicol 2010; 84:585-96. [PMID: 20502880 DOI: 10.1007/s00204-010-0554-4] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2010] [Accepted: 04/29/2010] [Indexed: 11/29/2022]
Abstract
Arsenic has been a recognized contaminant and toxicant, as well as a medicinal compound throughout human history. Populations throughout the world are exposed to arsenic and these exposures have been associated with a number of human cancers. Not much is known about the role of arsenic as a human carcinogen and more recently its role in non-cancerous diseases, such as cardiovascular disease, hypertension and diabetes mellitus have been uncovered. The health effects associated with arsenic are numerous and the association between arsenic exposure and human disease has intensified the search for molecular mechanisms that describe the biological activity of arsenic in humans and leads to the aforementioned disease states. Arsenic poses a human health risk due in part to the regulation of cellular signal transduction pathways and over the last few decades, some cellular mechanisms that account for arsenic toxicity, as well as, signal transduction pathways have been discovered. However, given the ubiquitous nature of arsenic in the environment, making sense of all the data remains a challenge. This review will focus on our knowledge of signal transduction pathways that are regulated by arsenic.
Collapse
Affiliation(s)
- Ingrid L Druwe
- Department of Pharmacology and Toxicology, The University of Arizona College of Pharmacy, 1703 E. Mabel Street, Tucson, AZ 85721, USA
| | | |
Collapse
|
32
|
Wnek SM, Jensen TJ, Severson PL, Futscher BW, Gandolfi AJ. Monomethylarsonous acid produces irreversible events resulting in malignant transformation of a human bladder cell line following 12 weeks of low-level exposure. Toxicol Sci 2010; 116:44-57. [PMID: 20375083 DOI: 10.1093/toxsci/kfq106] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Arsenic is a known human bladder carcinogen; however, the mechanisms underlying arsenical-induced bladder carcinogenesis are not understood. Previous research has demonstrated that exposure of a nontumorigenic human urothelial cell line, UROtsa, to 50 nM monomethylarsonous acid (MMA(III)) for 52 weeks resulted in malignant transformation. To focus research on the early mechanistic events leading to MMA(III)-induced malignancy, the goal of this research was to resolve the critical period in which continuous MMA(III) exposure (50 nM) induces the irreversible malignant transformation of UROtsa cells. An increased growth rate of UROtsa cells results after 12 weeks of MMA(III) exposure. Anchorage-independent growth occurred after 12 weeks with a continued increase in colony formation when 12-week exposed cells were cultured for an additional 12 or 24 weeks without MMA(III) exposure. UROtsa cells as early as 12 weeks MMA(III) exposure were tumorigenic in severe combined immunodeficiency mice with tumorigenicity increasing when 12-week exposed cells were cultured for an additional 12 or 24 weeks in the absence of MMA(III) exposure. To assess potential underlying mechanisms associated with the early changes that occur during MMA(III)-induced malignancy, DNA methylation was assessed in known target gene promoter regions. Although DNA methylation remains relatively unchanged after 12 weeks of exposure, aberrant DNA methylation begins to emerge after an additional 12 weeks in culture and continues to increase through 24 weeks in culture without MMA(III) exposure, coincident with the progression of a tumorigenic phenotype. Overall, these data demonstrate that 50 nM MMA(III) is capable of causing irreversible malignant transformation in UROtsa cells after 12 weeks of exposure. Having resolved an earlier timeline in which MMA(III)-induced malignant transformation occurs in UROtsa cells will allow for mechanistic studies focused on the critical biological changes taking place within these cells prior to 12 weeks of exposure, providing further evidence about potential mechanisms of MMA(III)-induced carcinogenesis.
Collapse
Affiliation(s)
- Shawn M Wnek
- Department of Pharmacology and Toxicology, University of Arizona, Tucson, Arizona 85721, USA.
| | | | | | | | | |
Collapse
|
33
|
|