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Kakavandi B, Rafiemanesh H, Giannakis S, Beheshtaeen F, Samoili S, Hashemi M, Abdi F. Establishing the relationship between Polycyclic Aromatic Hydrocarbons (PAHs) exposure and male infertility: A systematic review. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 250:114485. [PMID: 36608572 DOI: 10.1016/j.ecoenv.2022.114485] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 12/24/2022] [Accepted: 12/26/2022] [Indexed: 06/17/2023]
Abstract
It has been demonstrated that human exposure to environmental chemicals may have sperm genotoxic potentiality. Among the different classes, Polycyclic Aromatic Hydrocarbons (PAHs) have been receiving attention in recent years due to reports of sperm geno-toxicity, a series of reproductive defects and male infertility. This review aims to substantiate the effects of PAHs exposure on male infertility, with focus on the sperm characteristics (count, concentration, volume, motility, DNA damage, and morphology). To this end, international databases such as Cochrane Library, PubMed, Web of Science, Embase Ovid, Scopus, and Google Scholar were used to conduct a systematic search for papers on the subject, based on PRISMA guidelines, published up to 24 March 2022. The Newcastle-Ottawa Scale was subsequently used to assess the quality of the studies. The results showed that there is a significant negative relationship between PAHs metabolites and sperm volume, concentration, motility, morphology, as well as an observed DNA degeneration. Also, the CYP1A1 genotype polymorphisms were considered as a representative of PAHs exposure to infertility; the review highlights that polymorphisms of this genotype were more common in the infertile people. In overall, this work provides a solid summary of the existing works correlating PAHs exposure and male infertility, which could impulse further protective measures and informative campaigns on users, workers, and general population.
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Affiliation(s)
- Babak Kakavandi
- Research Center for Health, Safety and Environment, Alborz University of Medical Sciences, Karaj, Iran; Department of Environmental Health Engineering, Alborz University of Medical Sciences, Karaj, Iran
| | - Hossein Rafiemanesh
- Department of Epidemiology and Biostatistics, School of Public Health, Alborz University of Medical Sciences, Karaj, Iran; Non-communicable Diseases Research Center, Alborz University of Medical Sciences, Karaj, Iran
| | - Stefanos Giannakis
- Universidad Politécnica de Madrid, E.T.S. Ingenieros de Caminos, Canales y Puertos, Departamento de Ingeniería Civil: Hidráulica, Energía y Medio Ambiente, Unidad docente Ingeniería Sanitaria, c/ Profesor Aranguren, s/n, ES-28040 Madrid, Spain
| | - Fatemeh Beheshtaeen
- Student research committee, School of Nursing and Midwifery, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Sofia Samoili
- European Commission, Joint Research Centre (JRC), Seville 41092, Spain
| | - Masoumeh Hashemi
- Department of Midwifery, Arak Branch, Islamic Azad University, Arak, Iran
| | - Fatemeh Abdi
- Non-communicable Diseases Research Center, Alborz University of Medical Sciences, Karaj, Iran.
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Chen Q, Wang F, Yang H, Wang X, Zhang A, Ling X, Li L, Zou P, Sun L, Huang L, Chen H, Ao L, Liu J, Cao J, Zhou N. Exposure to fine particulate matter-bound polycyclic aromatic hydrocarbons, male semen quality, and reproductive hormones: The MARCHS study. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 280:116883. [PMID: 33794416 DOI: 10.1016/j.envpol.2021.116883] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 01/19/2021] [Accepted: 03/04/2021] [Indexed: 06/12/2023]
Abstract
Exposure to outdoor fine particulate matter (PM2.5)-bound polycyclic aromatic hydrocarbons (PAHs) is linked to reproductive dysfunction. However, it is unclear which component of PAHs is responsible for the adverse outcomes. In the Male Reproductive Health in Chongqing College Students (MARHCS) cohort study, we measured the exposure levels of 16 PAHs by collecting air PM2.5 particles and assessed eight PAHs metabolites from four parent PAHs, including naphthalene, fluorene, phenanthrene, and pyrene in urine samples. We investigated compositional profiles and variation characteristics for 16 PAHs in PM2.5, and then assessed the association between PAHs exposure and semen routine parameters, sperm chromatin structure, and serum hormone levels in 1452 samples. The results showed that naphthalene (95% CI: -17.989, -8.101), chrysene (95% CI: -64.894, -47.575), benzo[a]anthracene (95% CI: -63.227, -45.936) and all the high molecular weight (HMW) PAHs in PM2.5 were negatively associated with sperm normal morphology. Most of the low molecular weight (LMW) PAHs, such as acenaphthylene, fluorene, phenanthrene, fluoranthene, pyrene, chrysene, benzo[a]anthracene, ∑LMW PAHs and ∑16 PAHs, were correlated with increased sperm motility (all corrected P < 0.05). On the other hand, sperm normal morphology was all negatively associated with urinary metabolites of ∑OH-Nap (95% CI: -5.611, -0.536), ∑OH-Phe (95% CI: -5.741, -0.957), and ∑OH-PAHs (95% CI: -5.274, -0.361). Urinary concentrations of ∑OH-PAHs were found to be negatively associated with sperm high DNA stainability (HDS) (P = 0.023), while ∑OH-Phe were negatively associated with serum testosterone level and sperm HDS (P = 0.004). Spearman correlation analysis showed that except for the urinary OH-Nap metabolites, the rest of the urinary OH-PAHs metabolites were negatively correlated with their parent PAHs in air. The results of this study suggest that various PAHs' components may affect reproductive parameters differently. Inhalation of PAHs in air, especially HMW PAHs, may be a potential risk factor for male reproductive health.
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Affiliation(s)
- Qing Chen
- Key Lab of Medical Protection for Electromagnetic Radiation, Ministry of Education of China, Institute of Toxicology, College of Preventive Medicine, Army Medical University (Third Military Medical University), Chongqing, China
| | - Furong Wang
- Department of Toxicology, School of Public Health, Guizhou Medical University, Guiyang, Guizhou, China
| | - Huan Yang
- Key Lab of Medical Protection for Electromagnetic Radiation, Ministry of Education of China, Institute of Toxicology, College of Preventive Medicine, Army Medical University (Third Military Medical University), Chongqing, China
| | - Xiaogang Wang
- Key Lab of Medical Protection for Electromagnetic Radiation, Ministry of Education of China, Institute of Toxicology, College of Preventive Medicine, Army Medical University (Third Military Medical University), Chongqing, China
| | - Aihua Zhang
- Department of Toxicology, School of Public Health, Guizhou Medical University, Guiyang, Guizhou, China
| | - Xi Ling
- Key Lab of Medical Protection for Electromagnetic Radiation, Ministry of Education of China, Institute of Toxicology, College of Preventive Medicine, Army Medical University (Third Military Medical University), Chongqing, China
| | - Lianbing Li
- Key Laboratory of Birth Defects and Reproductive Health of the National Health and Family Planning Commission, Chongqing, China
| | - Peng Zou
- Key Lab of Medical Protection for Electromagnetic Radiation, Ministry of Education of China, Institute of Toxicology, College of Preventive Medicine, Army Medical University (Third Military Medical University), Chongqing, China
| | - Lei Sun
- Key Lab of Medical Protection for Electromagnetic Radiation, Ministry of Education of China, Institute of Toxicology, College of Preventive Medicine, Army Medical University (Third Military Medical University), Chongqing, China
| | - Linping Huang
- Key Lab of Medical Protection for Electromagnetic Radiation, Ministry of Education of China, Institute of Toxicology, College of Preventive Medicine, Army Medical University (Third Military Medical University), Chongqing, China
| | - Hongqiang Chen
- Key Lab of Medical Protection for Electromagnetic Radiation, Ministry of Education of China, Institute of Toxicology, College of Preventive Medicine, Army Medical University (Third Military Medical University), Chongqing, China
| | - Lin Ao
- Key Lab of Medical Protection for Electromagnetic Radiation, Ministry of Education of China, Institute of Toxicology, College of Preventive Medicine, Army Medical University (Third Military Medical University), Chongqing, China
| | - Jinyi Liu
- Key Lab of Medical Protection for Electromagnetic Radiation, Ministry of Education of China, Institute of Toxicology, College of Preventive Medicine, Army Medical University (Third Military Medical University), Chongqing, China
| | - Jia Cao
- Key Lab of Medical Protection for Electromagnetic Radiation, Ministry of Education of China, Institute of Toxicology, College of Preventive Medicine, Army Medical University (Third Military Medical University), Chongqing, China
| | - Niya Zhou
- Key Lab of Medical Protection for Electromagnetic Radiation, Ministry of Education of China, Institute of Toxicology, College of Preventive Medicine, Army Medical University (Third Military Medical University), Chongqing, China.
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Polycyclic aromatic hydrocarbons exposure and hematotoxicity in occupational population: A two-year follow-up study. Toxicol Appl Pharmacol 2019; 378:114622. [DOI: 10.1016/j.taap.2019.114622] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 05/13/2019] [Accepted: 06/07/2019] [Indexed: 01/29/2023]
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Yao Y, Wang D, Ma H, Li C, Chang X, Low P, Hammond SK, Turyk ME, Wang J, Liu S. The impact on T-regulatory cell related immune responses in rural women exposed to polycyclic aromatic hydrocarbons (PAHs) in household air pollution in Gansu, China: A pilot investigation. ENVIRONMENTAL RESEARCH 2019; 173:306-317. [PMID: 30951957 DOI: 10.1016/j.envres.2019.03.053] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 02/16/2019] [Accepted: 03/21/2019] [Indexed: 06/09/2023]
Abstract
Previous studies found associations between impairments of immune functions and exposure to polycyclic aromatic hydrocarbons (PAHs) in ambient air pollution in the U. S. and China. However, the results remain inconclusive due to the limitations of these studies. In this study, we aimed to examine the direction and magnitude of immune changes related to PAH exposure from household air pollution among rural women living in Gansu, China. Healthy village women (n = 34) were recruited and enrolled in the study. Questionnaires were administered. Blood and urine samples were collected and analyzed during non-heating (September 2017, "summer") and heating (January 2018, "winter") seasons. Urinary 1-hydroxypyrene (1-OHP) was quantified as the biomarker of PAH exposure. To evaluate Treg cell related immune functions, we examined immunoglobulin E (IgE), percent of T-regulatory (Treg) cells, and gene expression of following: forkhead box transcription factor 3 (Foxp3), transforming growth factor-β (TGF-β), interleukin 10 (IL-10), and interleukin 35 (IL-35), composed of interleukin-12 alpha (IL-12α) and Epstein-Barr-virus-induced gene 3 (EBi3). Urinary 8-hydroxy-2-deoxyguanosine (8-OHdG) was measured to evaluate oxidative DNA damage. The results showed that the concentration of 1-OHP increased from 0.90 to 17.4 μmol mol-Cr -1 from summer to winter (p < 0.001). Meanwhile, average percent of Treg cells decreased from 5.01% to 1.15% (p < 0.001); IgE and mRNA expressions of Foxp3, TGF-β, IL-10, IL-12α and EBi3 all significantly decreased (p < 0.001); Urinary 8-OHdG increased from 12.7 to 30.3 ng mg-Cr -1 (p < 0.001). The changes in 8-OHdG, Foxp3 and TGF-β were significantly associated with the increase of 1-OHP. The results suggested that we observed a substantial increase of PAH exposure in winter, which was significantly associated with the repression on Treg cell function and oxidative DNA damage. Exposure to PAHs in household air pollution possibly induced immune impairments among rural women in northwest China.
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Affiliation(s)
- Yueli Yao
- Department of Toxicology, School of Public Health, Lanzhou University, Lanzhou, Gansu, China
| | - Dong Wang
- Department of Toxicology, School of Public Health, Lanzhou University, Lanzhou, Gansu, China
| | - Haitao Ma
- Department of Toxicology, School of Public Health, Lanzhou University, Lanzhou, Gansu, China
| | - Chengyun Li
- Department of Toxicology, School of Public Health, Lanzhou University, Lanzhou, Gansu, China
| | - Xiaoru Chang
- Key Laboratory of Environmental Medicine and Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing, Jiangsu, China
| | - Patrick Low
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, CA, USA
| | - S Katharine Hammond
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, CA, USA
| | - Mary Ellen Turyk
- School of Public Health, University of Illinois, Chicago, IL, USA
| | - Junling Wang
- Department of Toxicology, School of Public Health, Lanzhou University, Lanzhou, Gansu, China.
| | - Sa Liu
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, CA, USA; School of Health Sciences, College of Health and Human Sciences, Purdue University, West Lafayette, IN, USA.
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Jeng HAC, Lin WY, Chao MR, Lin WY, Pan CH. Semen quality and sperm DNA damage associa -revised - final-finalted with oxidative stress in relation to exposure to polycyclic aromatic hydrocarbons. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART A, TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING 2019; 53:1221-1228. [PMID: 30623705 DOI: 10.1080/10934529.2018.1528035] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 05/28/2018] [Indexed: 06/09/2023]
Abstract
The cross-sectional study aimed to assess whether oxidative stress induced by exposure to polycyclic aromatic hydrocarbons (PAHs) affect semen quality and sperm DNA integrity. A total of 106 who met the inclusion criteria, were recruited from a coke-oven plant during their annual health checkup. The human subjects were grouped into the high exposure group, the low exposure group and the control based on PAH concentrations surrounding their employment locations. Semen quality, oxidative stress status, and sperm DNA damage [DNA fragmentation and 8-hydroxy-2'-deoxyguanosine (8-oxodGuo)] were assessed. Urinary 1-hydroxypyren (1-OHP) was used to assess human subject exposure to PAHs. The high exposure group experienced significantly lower sperm motility and normal morphology than the control (P = 0.046 and 0.049, respectively). The high exposure group also had significantly higher 8-oxoGuo concentrations in sperm than the control (P = 0.027). Urinary 1-OHP concentration was associated with decreased motility and less normal morphology, along with increased sperm oxidative damage and ROS concentrations. Oxidative stress induced by exposure to PAHs was associated with decreased sperm quality.
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Affiliation(s)
- Hueiwang Anna C Jeng
- a School of Community and Environmental Health , College of Health Sciences, Old Dominion University , Norfolk , Virginia , USA
| | - Wen Y Lin
- b Department of Occupational Medicine , Kaohsiung Medical University Hospital , Kaohsiung , Taiwan
| | - Mu R Chao
- c Department of Occupational Safety and Health , Chung Shan Medical University , Taichung , Taiwan
| | - Wen Y Lin
- b Department of Occupational Medicine , Kaohsiung Medical University Hospital , Kaohsiung , Taiwan
| | - Chih H Pan
- d Institute of Occupational Safety and Health, Council of Labor Affairs, Executive Yuan , Taipei , Taiwan
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Yang MH, Liao CC, Hung JH, Lai XT, Yen CH, Chen YMA. Utilizing proteomic approach to identify nuclear translocation related serine kinase phosphorylation site of GNMT as downstream effector for benzo[a]pyrene. J Food Drug Anal 2019; 27:603-609. [PMID: 30987732 PMCID: PMC9296196 DOI: 10.1016/j.jfda.2018.12.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 12/17/2018] [Accepted: 12/20/2018] [Indexed: 01/18/2023] Open
Abstract
Glycine N-methyltransferase (GNMT) protein is highly expressed in certain tissues, such as liver, pancreas, and prostate. GNMT serves multiple roles which include a methyl group transfer enzyme and a liver tumor suppressor. Benzo(a)pyrene (BaP), a family member of polycyclic aromatic hydrocarbon (PAH), is a known environmental carcinogen found in coal tar, tobacco smoke, barbecued food and incomplete combustion of auto fuel. BaP recruits cytochrome P450 to transform itself into benzo(a)pyrene-7,8-diol-9,10-epoxide (B(a) PDE), which covalently interacts with DNA causing tumorigenesis. BaP can be detoxified through GNMT and induces GNMT translocation into the cellular nucleus. GNMT translocation is accompanied by phosphorylation, but the role of phosphorylation in GNMT remains to be explored. Using liquid chromatography coupled with tandem mass spectrometry, this study identified serine 9 of GNMT as the phosphorylation site upon BaP treatment. When serine 9 was mutated and lost the capability to be phosphorylated, the occurrence of BaP-induced GNMT nuclear translocation was dramatically decreased. Also, this mutant from of GNMT lost the ability of phosphorylation and increased cytochrome P450 1A1 (Cyp1a) expression upon BaP treatment. In addition, protein kinase C (PKC) and c-Jun NH2-terminal kinase (JNK) may be required for such phosphorylation. Further characterization of phosphorylated GNMT for its link to BaP may bring new insights into chemical detoxification.
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Affiliation(s)
- Ming-Hui Yang
- Institute of Biological Chemistry, Academia Sinica, Taipei, 11529,
Taiwan
- Center for Infectious Disease and Cancer Research (CICAR), Kaohsiung Medical University, Kaohsiung 80708,
Taiwan
- Master Program in Clinical Pharmacogenomics and Pharmacoproteomics, College of Pharmacy, Taipei Medical University, Taipei, 11031,
Taiwan
- Research Center for Environmental Medicine, Kaohsiung Medical University, Kaohsiung 807,
Taiwan
| | - Chen-Chung Liao
- Proteomics Research Center, National Yang-Ming University, Taipei 11221,
Taiwan
| | - Jung-Hsien Hung
- Center for Infectious Disease and Cancer Research (CICAR), Kaohsiung Medical University, Kaohsiung 80708,
Taiwan
| | - Xiu-Ting Lai
- Institute of Microbiology and Immunology, National Yang-Ming University, Taipei 11221,
Taiwan
| | - Chia-Hung Yen
- Center for Infectious Disease and Cancer Research (CICAR), Kaohsiung Medical University, Kaohsiung 80708,
Taiwan
- Graduate Institute of Natural Products, College of Pharmacy, Kaohsiung Medical University, Kaohsiung 80708,
Taiwan
- Research Center for Natural products and Drug Development, Kaohsiung Medical University, Kaohsiung,
Taiwan
- Department of Medical Research, Kaohsiung Medical University Hospital, Kaohsiung,
Taiwan
- Corresponding author. E-mail addresses: (C.-H. Yen), (Y.-M.A. Chen)
| | - Yi-Ming Arthur Chen
- Center for Infectious Disease and Cancer Research (CICAR), Kaohsiung Medical University, Kaohsiung 80708,
Taiwan
- Master Program in Clinical Pharmacogenomics and Pharmacoproteomics, College of Pharmacy, Taipei Medical University, Taipei, 11031,
Taiwan
- Corresponding author. No. 100, Shih-Chuan Ist Rd, Kaohsiung City, 80708, Taiwan. Fax: +886 7 3222783
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Hanchi M, Campo L, Polledri E, Olgiati L, Consonni D, Saidane-Mosbahi D, Fustinoni S. Urinary 8-Oxo-7,8-Dihydro-2′-Deoxyguanosine in Tunisian Electric Steel Foundry Workers Exposed to Polycyclic Aromatic Hydrocarbons. Ann Work Expo Health 2017; 61:333-343. [DOI: 10.1093/annweh/wxw030] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 12/06/2016] [Indexed: 01/15/2023] Open
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Nguyen TTU, Kawanami S, Kawai K, Kasai H, Li YS, Inoue J, Ngoan LT, Horie S. Urinary 1-hydroxypyrene and 8-hydroxydeoxyguanosine levels among coke-oven workers for 2 consecutive days. J Occup Health 2014; 56:178-85. [PMID: 24598053 DOI: 10.1539/joh.13-0222-oa] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
OBJECTIVES This study evaluated the levels of exposure to polycyclic aromatic hydrocarbons (PAHs) and their relationship with oxidative DNA damage among Vietnamese coke-oven workers. METHODS We collected urine from 36 coke-oven workers (exposed group) at the beginning and end of the shift on 2 consecutive days. We also collected urine from 78 medical staff (control group). Information was collected by questionnaire about smoking status, drinking habit, and working position. Urinary 1-hydroxypyrene (1-OHP) and 8-hydroxydeoxyguanosine (8-OH-dG) were measured using HPLC. All statistical analyses were performed with SPSS version 19. RESULTS Urinary 1-OHP was significantly higher in the coke-oven workers than in the control group (p<0.05). Top-oven workers had the highest levels of internal exposure to PAHs, followed by side-oven and then bottom-oven workers (5.41, 4.41 and 1.35 ng/mg creatinine, respectively, at the end of the shift on day 2). Urinary 8-OH-dG was significantly higher in top- and side-oven workers at the end of the shift on day 2 (4.63 and 5.88 ng/mg creatinine, respectively) than in the control group (3.85 ng/mg creatinine). Based on a multi-regression analysis, smoking status had a significant effect on urinary 8-OH-dG (p=0.049). Urinary 1-OHP tended to have a positive correlation with urinary 8-OH-dG (p=0.070). CONCLUSIONS Vietnamese coke-oven workers were exposed to PAHs during their work shift. Urinary 1-OHP exceeded the recommended limit, and elevated oxidative DNA damage occurred in top- and side-oven workers on the second day of work. A tendency for positive correlation was found between urinary 1-OHP and urinary 8-OH-dG.
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Affiliation(s)
- Thi-To-Uyen Nguyen
- Department of Health Policy and Management, Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health
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The multi-functional roles of GNMT in toxicology and cancer. Toxicol Appl Pharmacol 2012; 266:67-75. [PMID: 23147572 DOI: 10.1016/j.taap.2012.11.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2012] [Revised: 11/02/2012] [Accepted: 11/03/2012] [Indexed: 11/23/2022]
Abstract
Although glycine N-methyltransferase (GNMT) has been discovered for five decades, its function was not elucidated until recently. In this review, we discuss the multiple roles of GNMT in toxicology and cancer. Besides catalyzing the production of methylglycine (sarcosine) in one carbon metabolism pathway, GNMT was found to be able to bind a number of polycyclic aromatic hydrocarbons and inhibit DNA adducts formation. Moreover, GNMT exerts protective effects against the cytotoxicity and carcinogenicity of benzo(a)pyrene and aflatoxin B(1) in vitro and in vivo. Occupational study showed that workers who had genotypes with higher GNMT promoter activity may have lower content of oxidative damaged DNA products in their urine. In terms of cancer, recent studies using GNMT knockout mouse models demonstrated that GNMT deficiency has high penetrance in inducing the development of steatohepatitis and hepatocellular carcinoma. In terms of the mechanism, besides dysregulation of epigenetic modification, insights have been provided by recent identification of two novel proteins interacting with GNMT-DEPTOR and NPC2. These studies suggest that GNMT not only is involved in mTOR signaling pathway, but also plays an important role in the intracellular trafficking of cholesterol. The implication of these findings to the preventive medicine and translational research will be discussed.
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