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Lynch HN, Kozal JS, Vincent MJ, Freid RD, Beckett EM, Brown S, Mathis C, Schoeny RS, Maier A. Systematic review of the human health hazards of propylene dichloride. Regul Toxicol Pharmacol 2023; 144:105468. [PMID: 37562533 DOI: 10.1016/j.yrtph.2023.105468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 06/05/2023] [Accepted: 08/05/2023] [Indexed: 08/12/2023]
Abstract
Propylene dichloride (PDC) is a chlorinated substance used primarily as an intermediate in basic organic chemical manufacturing. The United States Environmental Protection Agency (EPA) is currently evaluating PDC as a high-priority substance under the Toxic Substances Control Act (TSCA). We conducted a systematic review of the non-cancer and cancer hazards of PDC using the EPA TSCA and Integrated Risk Information System (IRIS) frameworks. We identified 12 epidemiological, 16 toxicokinetic, 34 experimental animal, and 49 mechanistic studies. Point-of-contact respiratory effects are the most sensitive non-cancer effects after inhalation exposure, and PDC is neither a reproductive nor a developmental toxicant. PDC is not mutagenic in vivo, and while in vitro evidence is mixed, DNA strand breaks consistently occur. Nasal tumors in rats and lung tumors in mice occurred after lifetime high-level inhalation exposure. Cholangiocarcinoma (CCA) was observed in Japanese print workers exposed to high concentrations of PDC. However, co-exposures, as well as liver parasites, hepatitis, and other risk factors, may also have contributed. The cancer mode of action (MOA) analysis revealed that PDC may act through multiple biological pathways occurring sequentially and/or simultaneously, although chronic tissue damage and inflammation likely dominate. Critically, health benchmarks protective of non-cancer effects are expected to protect against cancer in humans.
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Kozal JS, Lynch HN, Klapacz J, Schoeny RS, Jean PA, Maier A. Mode of action assessment for propylene dichloride as a human carcinogen. Chem Biol Interact 2023; 382:110382. [PMID: 36754223 DOI: 10.1016/j.cbi.2023.110382] [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: 08/02/2022] [Revised: 01/16/2023] [Accepted: 02/04/2023] [Indexed: 02/09/2023]
Abstract
As part of a systematic review of the non-cancer and cancer hazards of propylene dichloride (PDC), with a focus on potential carcinogenicity in workers following inhalation exposures, we determined that a mode of action (MOA)-centric framing of cancer effects was warranted. In our MOA analysis, we systematically reviewed the available mechanistic evidence for PDC-induced carcinogenesis, and we mapped biologically plausible MOA pathways and key events (KEs), as guided by the International Programme on Chemical Safety (IPCS)-MOA framework. For the identified pathways and KEs, biological concordance, essentiality of KEs, concordance of empirical observations among KEs, consistency, and analogy were evaluated. The results of this analysis indicate that multiple biologically plausible pathways may contribute to the cancer MOA for PDC, but that the relevant pathways vary by exposure route and level, tissue type, and species; further, more than one pathway may occur concurrently at high exposure levels. While several important data gaps exist, evidence from in vitro mechanistic studies, in vivo experimental animal studies, and ex vivo human tumor tissue analyses indicates that the predominant MOA pathway likely involves saturation of cytochrome p450 2E1 (CYP2E1)-glutathione (GSH) detoxification (molecular initiating event; MIE), accumulation of CYP2E1-oxidative metabolites, cytotoxicity, chronic tissue damage and inflammation, and ultimately tumor formation. Tumors may occur through several subsets of inflammatory KEs, including inflammation-induced aberrant expression of activation-induced cytidine deaminase (AID), which causes DNA strand breaks and mutations and can lead to tumors with a characteristic mutational signature found in occupational cholangiocarcinoma. Dose concordance analysis showed that low-dose mutagenicity (from any pathway) is not a driving MOA, and that prevention of target tissue damage and inflammation (associated with saturation of CYP2E1-GSH detoxification) is expected to also prevent the cascade of processes responsible for tumor formation.
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Affiliation(s)
| | | | - Joanna Klapacz
- Toxicology and Environmental Research and Consulting, The Dow Chemical Company, Midland, MI, 48674, USA
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Takizawa R, Ichihara S, Zong C, Kinoshita K, Sakurai T, Ikegami A, Mise N, Ichihara G. 1,2-Dichloropropane induces γ-H2AX expression in human cholangiocytes only in the presence of macrophages. Toxicol Lett 2021; 349:134-144. [PMID: 34153406 DOI: 10.1016/j.toxlet.2021.06.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 05/24/2021] [Accepted: 06/15/2021] [Indexed: 01/13/2023]
Abstract
Recent epidemiological studies reported cases of cholangiocarcinoma in workers exposed to 1,2-dichloropropane (1,2-DCP) in an offset proof printing factory in Japan. The present study investigated the effects of 1,2-DCP on the expression of histone family member X (H2AX) phosphorylated on Ser 139 (γ-H2AX), a marker of DNA double strand break, in human immortalized cholangiocytes MMNK-1 cells. Mono-cultures of MMNK-1 cells and co-cultures of MMNK-1 cells with THP-1 macrophages were exposed to 1,2-DCP at concentrations of 100 and 500 μM for 24 h. Expression of γ-H2AX was visualized by immunofluorescence staining. Exposure to 1,2-DCP had no effect on the expression of γ-H2AX in mono-cultured MMNK-1 cells, but significantly increased the number of nuclear foci stained by γ-H2AX in MMNK-1 cells co-cultured with THP-1 macrophages. Exposure to 1,2-DCP also significantly increased the levels of tumor necrosis factor (TNF)-α and interleukin (IL)-6 in co-cultured MMNK-1 cells. The results suggest that macrophages play a critical role by producing cytokines in 1,2-DCP-induced DNA double strand break in MMNK-1 cells.
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Affiliation(s)
- Ryoya Takizawa
- Department of Occupational and Environmental Health, Tokyo University of Science, Noda, Japan; Department of Environmental and Preventive Medicine, Jichi Medical University School of Medicine, Shimotsuke, Japan
| | - Sahoko Ichihara
- Department of Environmental and Preventive Medicine, Jichi Medical University School of Medicine, Shimotsuke, Japan
| | - Cai Zong
- Department of Occupational and Environmental Health, Tokyo University of Science, Noda, Japan
| | - Kazuo Kinoshita
- Evolutionary Medicine, Shizuoka Graduate University of Public Health, Shizuoka, Japan
| | - Toshihiro Sakurai
- Department of Occupational and Environmental Health, Tokyo University of Science, Noda, Japan
| | - Akihiko Ikegami
- Department of Environmental and Preventive Medicine, Jichi Medical University School of Medicine, Shimotsuke, Japan
| | - Nathan Mise
- Department of Environmental and Preventive Medicine, Jichi Medical University School of Medicine, Shimotsuke, Japan
| | - Gaku Ichihara
- Department of Occupational and Environmental Health, Tokyo University of Science, Noda, Japan.
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Zhang X, Morikawa K, Mori Y, Zong C, Zhang L, Garner E, Huang C, Wu W, Chang J, Nagashima D, Sakurai T, Ichihara S, Oikawa S, Ichihara G. Proteomic analysis of liver proteins of mice exposed to 1,2-dichloropropane. Arch Toxicol 2020; 94:2691-2705. [PMID: 32435916 DOI: 10.1007/s00204-020-02785-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 05/07/2020] [Indexed: 11/29/2022]
Abstract
1,2-Dichloropropane (1,2-DCP) is recognized as the causative agent for cholangiocarcinoma among offset color proof-printing workers in Japan. The aim of the present study was to characterize the molecular mechanisms of 1,2-DCP-induced hepatotoxic effects by proteomic analysis. We analyzed quantitatively the differential expression of proteins in the mouse liver and investigated the role of P450 in mediating the effects of 1,2-DCP. Male C57BL/6JJcl mice were exposed to 0, 50, 250, or 1250 ppm 1,2-DCP and treated with either 1-aminobenzotriazole (1-ABT), a nonselective P450 inhibitor, or saline, for 8 h/day for 4 weeks. Two-dimensional difference in gel electrophoresis (2D-DIGE) combined with matrix-assisted laser-desorption ionization time-of-flight mass spectrometry (MALDI-TOF/TOF/MS) was used to detect and identify proteins affected by the treatment. PANTHER overrepresentation test on the identified proteins was conducted. 2D-DIGE detected 61 spots with significantly different intensity between 0 and 250 ppm 1,2-DCP groups. Among them, 25 spots were identified by MALDI-TOF/TOF/MS. Linear regression analysis showed significant trend with 1,2-DCP level in 17 proteins in mice co-treated with 1-ABT. 1-ABT mitigated the differential expression of these proteins. The gene ontology enrichment analysis showed overrepresentation of proteins functionally related to nickel cation binding, carboxylic ester hydrolase activity, and catalytic activity. The results demonstrated that exposure to 1,2-DCP altered the expression of proteins related with catalytic and carboxylic ester hydrolase activities, and that such effect was mediated by P450 enzymatic activity.
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Affiliation(s)
- Xiao Zhang
- Department of Occupational and Environmental Health, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, 278-8510, Japan.,Department of Toxicology, Guangdong Province Hospital for Occupational Disease Prevention and Treatment, Guangzhou, 510300, People's Republic of China
| | - Kota Morikawa
- Department of Occupational and Environmental Health, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, 278-8510, Japan
| | - Yurie Mori
- Mie University Graduate School of Medicine, Tsu, 514-8507, Japan
| | - Cai Zong
- Department of Occupational and Environmental Health, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, 278-8510, Japan
| | - Lingyi Zhang
- Department of Occupational and Environmental Health, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, 278-8510, Japan
| | - Edwin Garner
- Lovelace Respiratory Research Institute, Albuquerque, NM, 87108, USA
| | - Chinyen Huang
- Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan
| | - Wenting Wu
- Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan
| | - Jie Chang
- Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan
| | - Daichi Nagashima
- Department of Occupational and Environmental Health, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, 278-8510, Japan
| | - Toshihiro Sakurai
- Department of Occupational and Environmental Health, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, 278-8510, Japan
| | - Sahoko Ichihara
- Jichi Medical University School of Medicine, Shimotsuke, 329-0498, Japan
| | - Shinji Oikawa
- Mie University Graduate School of Medicine, Tsu, 514-8507, Japan
| | - Gaku Ichihara
- Department of Occupational and Environmental Health, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, 278-8510, Japan.
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Zhang X, Zong C, Zhang L, Garner E, Sugie S, Huang C, Wu W, Chang J, Sakurai T, Kato M, Ichihara S, Kumagai S, Ichihara G. Exposure of Mice to 1,2-Dichloropropane Induces CYP450-Dependent Proliferation and Apoptosis of Cholangiocytes. Toxicol Sci 2017; 162:559-569. [DOI: 10.1093/toxsci/kfx272] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Affiliation(s)
- Xiao Zhang
- Department of Occupational and Environmental Health, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda 278-8510, Japan
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
- Guangdong Provincial Key Laboratory of Occupational Disease Prevention and Treatment, Guangdong Province Hospital for Occupational Disease Prevention and Treatment, Guangzhou 510300, China
| | - Cai Zong
- Department of Occupational and Environmental Health, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda 278-8510, Japan
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Lingyi Zhang
- Department of Occupational and Environmental Health, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda 278-8510, Japan
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Edwin Garner
- Lovelace Respiratory Research Institute, Albuquerque, New Mexico 87108
| | - Shigeyuki Sugie
- Department of Diagnostic Pathology, Asahi University Murakami Memorial Hospital, Gifu 500-8523, Japan
| | - Chinyen Huang
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Wenting Wu
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Jie Chang
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Toshihiro Sakurai
- Department of Occupational and Environmental Health, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda 278-8510, Japan
| | - Masashi Kato
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Sahoko Ichihara
- Department of Environmental and Preventive Medicine, Jichi Medical University School of Medicine, Shimotsuke 329-0498, Japan
| | - Shinji Kumagai
- Department of Occupational and Environmental Management, University of Occupational and Environmental Health, Kitakyushu 807-8555, Japan
| | - Gaku Ichihara
- Department of Occupational and Environmental Health, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda 278-8510, Japan
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
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Spontaneous Production of Glutathione-Conjugated Forms of 1,2-Dichloropropane: Comparative Study on Metabolic Activation Processes of Dihaloalkanes Associated with Occupational Cholangiocarcinoma. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:9736836. [PMID: 28555163 PMCID: PMC5438856 DOI: 10.1155/2017/9736836] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 03/17/2017] [Accepted: 03/20/2017] [Indexed: 12/18/2022]
Abstract
Recently, epidemiological studies revealed a positive relationship between an outbreak of occupational cholangiocarcinoma and exposure to organic solvents containing 1,2-dichloropropane (1,2-DCP). In 1,2-DCP-administered animal models, we previously found biliary excretion of potentially oncogenic metabolites consisting of glutathione- (GSH-) conjugated forms of 1,2-DCP (GS-DCPs); however, the GS-DCP production pathway remains unknown. To enhance the understanding of 1,2-DCP-related risks to human health, we examined the reactivity of GSH with 1,2-DCP in vitro and compared it to that with dichloromethane (DCM), the other putative substance responsible for occupational cholangiocarcinoma. Our results showed that 1,2-DCP was spontaneously conjugated with GSH, whereas this spontaneous reaction was hardly detected between DCM and GSH. Further analysis revealed that glutathione S-transferase theta 1 (GSTT1) exhibited less effect on the 1,2-DCP reaction as compared with that observed for DCM. Although GSTT1-mediated bioactivation of dihaloalkanes could be a plausible explanation for the production of reactive metabolites related to carcinogenesis based on previous studies, this catalytic pathway might not mainly contribute to 1,2-DCP-related occupational cholangiocarcinoma. Considering the higher catalytic activity of GSTT1 on DCM as compared with that on 1,2-DCP, our findings suggested differences in the activation processes associated with 1,2-DCP and DCM metabolism.
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Yanagiba Y, Suda M, Toyooka T, Wang RS. [Chemical management and occupational cholangiocarcinoma among workers in printing industry]. SANGYO EISEIGAKU ZASSHI = JOURNAL OF OCCUPATIONAL HEALTH 2016; 58:78-83. [PMID: 26983494 DOI: 10.1539/sangyoeisei.wadai15005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
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