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Huang Y, Wang J, Huang S, Zhang X, Hu J. 5-Lipoxygenase Contributes to Benzo[a]pyrene-Induced Cytotoxicity and DNA Damage in Human Bronchial Epithelial Cells. Int J Toxicol 2023; 42:172-181. [PMID: 36537154 DOI: 10.1177/10915818221146286] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Metabolic activation of indirect-acting carcinogens in target organs is a recognized mechanism of carcinogenesis. This study aimed to determine the role of benzo[a]pyrene (BaP) metabolism enzymes lipoxygenase (LOX), cytochrome P4501A1 (CYP1A1), and prostaglandin synthetase (PGS) in the cytotoxicity and DNA damage induced by BaP in the human tracheobronchial epithelial cells (HBECs) using RNA interference strategy and metabolic enzyme inhibitors. Our results showed that in three epithelial cell lines (HBE, HTR-8/SVneo, and HaCat), BaP significantly upregulated 5-LOX protein expression. 15-LOX-2 expression also increased with increasing BaP concentration, but the change was less pronounced than that of 5-LOX. BaP caused significant cytotoxicity, DNA strand breaks, and 8-hydroxy-2'-deoxyguanosine formation in HBE, which was inhibited by 5-LOXshRNA, a specific inhibitor of 5-LOX (AA861), the CYP1A1 inhibitor α-naphthoflavone, and the PGS inhibitor naproxen. The protective effects of 5-LOXshRNA were stronger than AA861, naproxen and α-naphthoflavone. We conclude that BaP may be activated more by 5-LOX than by CYP1A1 and PGS to produce cytotoxicity and DNA damage in HBE.
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Affiliation(s)
- Yun Huang
- Department of Occupational and Environmental Health, Xiangya School of Public Health, 12570Central South University, Changsha, China
| | - Jing Wang
- Shanxi Provincial Center for Disease Control and Prevention, Taiyuan, China
| | - Shaoling Huang
- 633786Changsha Center for Disease Control and Prevention, Changsha, China
| | - Xinge Zhang
- 595060Hunan Provincial Center for Disease Control and Prevention, Changsha, China
| | - Jianan Hu
- Department of Occupational and Environmental Health, Xiangya School of Public Health, 12570Central South University, Changsha, China
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2
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Hannon SL, Ding X. Assessing cytochrome P450 function using genetically engineered mouse models. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2022; 95:253-284. [PMID: 35953157 PMCID: PMC10544722 DOI: 10.1016/bs.apha.2022.05.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The ability to knock out and/or humanize different genes in experimental animals, globally or in cell- and tissue-specific patterns, has revolutionized scientific research in many areas. Genetically engineered mouse models, including knockout models, transgenic models, and humanized models, have played important roles in revealing the in vivo functions of various cytochrome P450 (CYP) enzymes. These functions are very diverse, ranging from the biotransformation of drugs and other xenobiotics, events that often dictate their pharmacokinetic or toxicokinetic properties and the associated therapeutic or adverse actions, to the metabolism of endogenous compounds, such as steroid hormones and other bioactive substances, that may determine susceptibility to many diseases, such as cancer and metabolic diseases. In this review, we provide a comprehensive list of Cyp-knockout, human CYP-transgenic, and CYP-humanized mouse models that target genes in the CYP1-4 gene families, and highlight their utility in assessing the in vivo metabolism, bioactivation, and toxicity of various xenobiotic compounds, including therapeutic agents and chemical carcinogens. We aim to showcase the advantages of utilizing these mouse models for in vivo drug metabolism and toxicology studies, and to encourage and facilitate greater utility of engineered mouse models to further improve our knowledge of the in vivo functions of various P450 enzymes, which is integral to our ability to develop safer and more effective therapeutics and to identify individuals predisposed to adverse drug reactions or environmental diseases.
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Affiliation(s)
- Sarrah L Hannon
- Department of Pharmacology and Toxicology, Ken R. Coit College of Pharmacy, The University of Arizona, Tucson, AZ, United States
| | - Xinxin Ding
- Department of Pharmacology and Toxicology, Ken R. Coit College of Pharmacy, The University of Arizona, Tucson, AZ, United States.
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3
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Wang L, Xu W, Ma L, Zhang S, Zhang K, Ye P, Xing G, Zhang X, Cao Y, Xi J, Gu J, Luan Y. Detoxification of benzo[a]pyrene primarily depends on cytochrome P450, while bioactivation involves additional oxidoreductases including 5-lipoxygenase, cyclooxygenase, and aldo-keto reductase in the liver. J Biochem Mol Toxicol 2017; 31. [PMID: 28111842 DOI: 10.1002/jbt.21902] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Revised: 12/26/2016] [Accepted: 01/03/2017] [Indexed: 02/02/2023]
Abstract
Cytochrome P450s are involved in detoxification and activation of benzo[a]pyrene (BaP) with unclear balance and unknown contribution of other oxidoreductases. Here, we investigated the BaP and BaP-induced mutagenicity in hepatic and extra-hepatic tissues using hepatic P450 reductase null (HRN) gpt mice. After 2-week treatment (50 mg/kg, i.p. 4 days), BaP in the liver and lung of HRN-gpt mice were increased. BaP promoted gpt mutant frequency (MF) in HRN-gpt mice liver. MF of gpt in the lung and Pig-a in hematopoietic cells induced by BaP in HRN-gpt mice were increased than in gpt mice. BaP-7,8-diol-9,10-epoxide (BPDE)-DNA adducts in vitro was analyzed for enzymes detection in BaP bioactivation. Specific inhibitors of 5-lipoxygenase, cyclooxygenase-1&2, and aldo-keto reductase resulted in more than 80% inhibition rate in the DNA adduct formation, further confirmed by Macaca fascicularis hepatic S9 system. Our results suggested the detoxification of BaP primarily depends on cytochrome P450, while the bioactivation involves additional oxidoreductases.
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Affiliation(s)
- Liupeng Wang
- Hongqiao International Institute of Medicine, Shanghai Tong Ren Hospital and Faculty of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, People's Republic of China
| | - Wenwei Xu
- Tong Ren Hospital Affiliated To Shanghai Jiao Tong University School of Medicine, Shanghai, 200336, People's Republic of China
| | - Leilei Ma
- Hongqiao International Institute of Medicine, Shanghai Tong Ren Hospital and Faculty of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, People's Republic of China
| | - Suxing Zhang
- KG Pharma Limited, Foshan, 528000, People's Republic of China
| | - Kezhi Zhang
- KG Pharma Limited, Foshan, 528000, People's Republic of China
| | - Peizhen Ye
- KG Pharma Limited, Foshan, 528000, People's Republic of China
| | - Guozhen Xing
- Jiangsu Tripod Preclinical Research Laboratories, Pukou Economic Development Zone, Nanjing, People's Republic of China
| | - Xuefeng Zhang
- Jiangsu Tripod Preclinical Research Laboratories, Pukou Economic Development Zone, Nanjing, People's Republic of China
| | - Yiyi Cao
- Hongqiao International Institute of Medicine, Shanghai Tong Ren Hospital and Faculty of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, People's Republic of China
| | - Jing Xi
- Hongqiao International Institute of Medicine, Shanghai Tong Ren Hospital and Faculty of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, People's Republic of China
| | - Jun Gu
- Wadsworth Center, New York State Department of Health, Albany, NY, 12201-0509, USA
| | - Yang Luan
- Hongqiao International Institute of Medicine, Shanghai Tong Ren Hospital and Faculty of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, People's Republic of China
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4
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Chun YJ, Kim D. Cancer Activation and Polymorphisms of Human Cytochrome P450 1B1. Toxicol Res 2016; 32:89-93. [PMID: 27123158 PMCID: PMC4843978 DOI: 10.5487/tr.2016.32.2.089] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 02/29/2016] [Accepted: 03/01/2016] [Indexed: 11/20/2022] Open
Abstract
Human cytochrome P450 enzymes (P450s, CYPs) are major oxidative catalysts that metabolize various xenobiotic and endogenous compounds. Many carcinogens induce cancer only after metabolic activation and P450 enzymes play an important role in this phenomenon. P450 1B1 mediates bioactivation of many procarcinogenic chemicals and carcinogenic estrogen. It catalyzes the oxidation reaction of polycyclic aromatic carbons, heterocyclic and aromatic amines, and the 4-hydroxylation reaction of 17β-estradiol. Enhanced expression of P450 1B1 promotes cancer cell proliferation and metastasis. There are at least 25 polymorphic variants of P450 1B1 and some of these have been reported to be associated with eye diseases. In addition, P450 1B1 polymorphisms can greatly affect the metabolic activation of many procarcinogenic compounds. It is necessary to understand the relationship between metabolic activation of such substances and P450 1B1 polymorphisms in order to develop rational strategies for the prevention of its toxic effect on human health.
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Affiliation(s)
| | - Donghak Kim
- Department of Biological Sciences, Konkuk University, Seoul, Korea
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5
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Kwon YJ, Baek HS, Ye DJ, Shin S, Kim D, Chun YJ. CYP1B1 Enhances Cell Proliferation and Metastasis through Induction of EMT and Activation of Wnt/β-Catenin Signaling via Sp1 Upregulation. PLoS One 2016; 11:e0151598. [PMID: 26981862 PMCID: PMC4794175 DOI: 10.1371/journal.pone.0151598] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2015] [Accepted: 03/01/2016] [Indexed: 01/06/2023] Open
Abstract
Cytochrome P450 1B1 (CYP1B1) is a major E2 hydroxylase involved in the metabolism of potential carcinogens. CYP1B1 expression has been reported to be higher in tumors compared to normal tissues, especially in hormone-related cancers including breast, ovary, and prostate tumors. To explore the role of CYP1B1 in cancer progression, we investigated the action of CYP1B1 in cells with increased CYP1B1 via the inducer 7,12-dimethylbenz[α]anthracene (DMBA) or an overexpression vector, in addition to decreased CYP1B1 via the inhibitor tetramethoxystilbene (TMS) or siRNA knockdown. We observed that CYP1B1 promoted cell proliferation, migration, and invasion in MCF-7 and MCF-10A cells. To understand its molecular mechanism, we measured key oncogenic proteins including β-catenin, c-Myc, ZEB2, and matrix metalloproteinases following CYP1B1 modulation. CYP1B1 induced epithelial-mesenchymal transition (EMT) and activated Wnt/β-catenin signaling via upregulation of CTNNB1, ZEB2, SNAI1, and TWIST1. Sp1, a transcription factor involved in cell growth and metastasis, was positively regulated by CYP1B1, and suppression of Sp1 expression by siRNA or DNA binding activity using mithramycin A blocked oncogenic transformation by CYP1B1. Therefore, we suggest that Sp1 acts as a key mediator for CYP1B1 action. Treatment with 4-hydroxyestradiol (4-OHE2), a major metabolite generated by CYP1B1, showed similar effects as CYP1B1 overexpression, indicating that CYP1B1 activity mediated various oncogenic events in cells. In conclusion, our data suggests that CYP1B1 promotes cell proliferation and metastasis by inducing EMT and Wnt/β-catenin signaling via Sp1 induction.
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Affiliation(s)
- Yeo-Jung Kwon
- College of Pharmacy, Chung-Ang University, Seoul, Korea
| | | | - Dong-Jin Ye
- College of Pharmacy, Chung-Ang University, Seoul, Korea
| | - Sangyun Shin
- College of Pharmacy, Chung-Ang University, Seoul, Korea
| | - Donghak Kim
- Department of Biological Sciences, Konkuk University, Seoul, Korea
| | - Young-Jin Chun
- College of Pharmacy, Chung-Ang University, Seoul, Korea
- * E-mail:
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6
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Elentner A, Ortner D, Clausen B, Gonzalez FJ, Fernández-Salguero PM, Schmuth M, Dubrac S. Skin response to a carcinogen involves the xenobiotic receptor pregnane X receptor. Exp Dermatol 2015; 24:835-40. [PMID: 26013842 PMCID: PMC6334296 DOI: 10.1111/exd.12766] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/19/2015] [Indexed: 12/20/2022]
Abstract
Skin is in daily contact with potentially harmful molecules from the environment such as cigarette smoke, automobile emissions, industrial soot and groundwater. Pregnane X receptor (PXR) is a transcription factor expressed in liver and intestine that is activated by xenobiotic chemicals including drugs and environmental pollutants. Topical application of the tumor initiator 7,12-dimethylbenz(a)anthracene (DMBA) enhances Pxr, Cyp1a1, Cyp1b1 and Cyp3a11, but not Ahr expression in the skin. Surprisingly, DMBA-induced Pxr upregulation is largely impaired in Langerin(+) cell-depleted skin, suggesting that DMBA mainly triggers Pxr in Langerin(+) cells. Furthermore, PXR deficiency protects from DNA damage in epidermal cells but to a lesser extent than aryl hydrocarbon receptor (AHR) deficiency. Interestingly, skin exposure to low doses of DMBA induces migration of PXR-deficient but not of wild-type and AHR-deficient Langerhans cells (LCs). PXR-humanized mice show a marked increase in DNA damage to epidermal cells after topical application of DMBA, demonstrating relevance of these findings in human tissue. This is the first report suggesting that carcinogens might trigger PXR in epidermal cells, particularly in LCs, thus leading to DNA damage. Further studies are required to better delineate the role of PXR in cutaneous carcinogenesis.
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Affiliation(s)
- Andreas Elentner
- Department of Dermatology and Venereology, Medical University of Innsbruck, Innsbruck, Austria
| | - Daniela Ortner
- Department of Dermatology and Venereology, Medical University of Innsbruck, Innsbruck, Austria
| | - Björn Clausen
- Institute for Molecular Medicine, University Medical Center of the Johannes, Gutenberg-University Mainz, Mainz, Germany
| | - Frank J. Gonzalez
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Pedro M. Fernández-Salguero
- Department of Biochemistry, Molecular Biology and Genetic, Faculty of Sciences, University of Extremadura, Badajoz, Spain
| | - Matthias Schmuth
- Department of Dermatology and Venereology, Medical University of Innsbruck, Innsbruck, Austria
| | - Sandrine Dubrac
- Department of Dermatology and Venereology, Medical University of Innsbruck, Innsbruck, Austria
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7
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Moffat I, Chepelev N, Labib S, Bourdon-Lacombe J, Kuo B, Buick JK, Lemieux F, Williams A, Halappanavar S, Malik A, Luijten M, Aubrecht J, Hyduke DR, Fornace AJ, Swartz CD, Recio L, Yauk CL. Comparison of toxicogenomics and traditional approaches to inform mode of action and points of departure in human health risk assessment of benzo[a]pyrene in drinking water. Crit Rev Toxicol 2015; 45:1-43. [PMID: 25605026 DOI: 10.3109/10408444.2014.973934] [Citation(s) in RCA: 114] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Toxicogenomics is proposed to be a useful tool in human health risk assessment. However, a systematic comparison of traditional risk assessment approaches with those applying toxicogenomics has never been done. We conducted a case study to evaluate the utility of toxicogenomics in the risk assessment of benzo[a]pyrene (BaP), a well-studied carcinogen, for drinking water exposures. Our study was intended to compare methodologies, not to evaluate drinking water safety. We compared traditional (RA1), genomics-informed (RA2) and genomics-only (RA3) approaches. RA2 and RA3 applied toxicogenomics data from human cell cultures and mice exposed to BaP to determine if these data could provide insight into BaP's mode of action (MOA) and derive tissue-specific points of departure (POD). Our global gene expression analysis supported that BaP is genotoxic in mice and allowed the development of a detailed MOA. Toxicogenomics analysis in human lymphoblastoid TK6 cells demonstrated a high degree of consistency in perturbed pathways with animal tissues. Quantitatively, the PODs for traditional and transcriptional approaches were similar (liver 1.2 vs. 1.0 mg/kg-bw/day; lungs 0.8 vs. 3.7 mg/kg-bw/day; forestomach 0.5 vs. 7.4 mg/kg-bw/day). RA3, which applied toxicogenomics in the absence of apical toxicology data, demonstrates that this approach provides useful information in data-poor situations. Overall, our study supports the use of toxicogenomics as a relatively fast and cost-effective tool for hazard identification, preliminary evaluation of potential carcinogens, and carcinogenic potency, in addition to identifying current limitations and practical questions for future work.
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Affiliation(s)
- Ivy Moffat
- Water and Air Quality Bureau, Health Canada, Ottawa, ON, Canada.,Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada
| | - Nikolai Chepelev
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada
| | - Sarah Labib
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada
| | - Julie Bourdon-Lacombe
- Water and Air Quality Bureau, Health Canada, Ottawa, ON, Canada.,Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada
| | - Byron Kuo
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada
| | - Julie K Buick
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada
| | - France Lemieux
- Water and Air Quality Bureau, Health Canada, Ottawa, ON, Canada
| | - Andrew Williams
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada
| | - Sabina Halappanavar
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada
| | - Amal Malik
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada
| | - Mirjam Luijten
- National Institute for Public Health and the Environment, Bilthoven, The Netherlands
| | | | - Daniel R Hyduke
- Biological Engineering Department, Utah State University, Logan, UT, USA
| | - Albert J Fornace
- Department of Biochemistry and Molecular and Cellular Biology, Georgetown University, Washington, DC, USA
| | - Carol D Swartz
- Integrated Laboratory Systems Inc., Research Triangle Park, NC, USA
| | - Leslie Recio
- Integrated Laboratory Systems Inc., Research Triangle Park, NC, USA
| | - Carole L Yauk
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada
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8
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Labib S, Guo CH, Williams A, Yauk CL, White PA, Halappanavar S. Toxicogenomic outcomes predictive of forestomach carcinogenesis following exposure to benzo(a)pyrene: Relevance to human cancer risk. Toxicol Appl Pharmacol 2013; 273:269-80. [DOI: 10.1016/j.taap.2013.05.027] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Revised: 05/17/2013] [Accepted: 05/21/2013] [Indexed: 02/05/2023]
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9
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Nebert DW, Shi Z, Gálvez-Peralta M, Uno S, Dragin N. Oral benzo[a]pyrene: understanding pharmacokinetics, detoxication, and consequences--Cyp1 knockout mouse lines as a paradigm. Mol Pharmacol 2013; 84:304-13. [PMID: 23761301 DOI: 10.1124/mol.113.086637] [Citation(s) in RCA: 101] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Benzo[a]pyrene (BaP) is a prototypical polycyclic aromatic hydrocarbon (PAH); this ubiquitous environmental carcinogenic agent is found in tobacco smoke, charcoal-grilled foods, and PAH-contaminated surfaces of roofs, playgrounds, and highways. Cytochrome P450 1 wild-type, Cyp1a2(-/-), Cyp1b1(-/-), or Cyp1a2/1b1(-/-) knockouts, and mice with Cyp1a1 expression deleted in hepatocytes can ingest large oral BaP doses (125 mg/kg/d) without apparent toxicity. Cyp1a1(-/-) and Cyp1a1/1a2(-/-) knockouts and mice with Cyp1a1 expression deleted in gastrointestinal (GI) tract epithelial cells develop immunotoxicity and die within 32 days, indicating that GI tract inducible CYP1A1 is absolutely required for detoxication of oral BaP. Cyp1a1/1b1(-/-) and Cyp1a1/1a2/1b1(-/-) mice are rescued from immunosuppression and early death due to absent metabolic activation of BaP by CYP1B1 in immune cells. Ten-fold lower oral BaP doses result in adenocarcinoma of the proximal small intestine (PSI) in Cyp1a1(-/-) mice; Cyp1a1/1b1(-/-) double-knockout mice show no PSI cancer but develop squamous cell carcinoma of the preputial gland duct (PGD). BaP-metabolizing CYP1B1 in the PSI and CYP3A59 in the PGD are the most likely candidates to participate in tumor initiation in the epithelial cells of these two tissues; oncogenes and tumor-suppressor genes upregulated and downregulated during tumorigenesis are completely different between these tissues. This "oral BaP Cyp1" mouse paradigm represents a powerful teaching tool, showing that gene-environment interactions depend on route-of-administration: the same oral, but not intraperitoneal, BaP exposure leads to dramatic differences in target-organ toxicity and tumor type as a function of dose and Cyp1 genotype.
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Affiliation(s)
- Daniel W Nebert
- Department of Environmental Health, and the Center for Environmental Genetics, University of Cincinnati Medical Center, P.O. Box 670056, Cincinnati, OH 45267-0056, USA.
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Dong H, Shertzer HG, Genter MB, Gonzalez FJ, Vasiliou V, Jefcoate C, Nebert DW. Mitochondrial targeting of mouse NQO1 and CYP1B1 proteins. Biochem Biophys Res Commun 2013; 435:727-32. [PMID: 23692925 DOI: 10.1016/j.bbrc.2013.05.051] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Accepted: 05/12/2013] [Indexed: 10/26/2022]
Abstract
Four dioxin-inducible enzymes--NAD(P)H: quinone oxidoreductase-1 (NQO1) and three cytochromes P450 (CYP1A1, CYP1A2 & CYP1B1)--are implicated in both detoxication and metabolic activation of various endobiotics and xenobiotics. NQO1 is generally regarded as a cytosolic enzyme; whereas CYP1 proteins are located primarily in endoplasmic reticulum (ER), CYP1A1 and CYP1A2 proteins are also targeted to mitochondria. This lab has generated Cyp1a1(mc/mc) and Cyp1a1(mtt/mtt) knock-in mouse lines in which CYP1A1 protein is targeted exclusively to ER (microsomes) and mitochondria, respectively. Comparing dioxin-treated Cyp1(+/+) wild-type, Cyp1a1(mc/mc), Cyp1a1(mtt/mtt), and Cyp1a1(-/-), Cyp1b1(-/-) and Nqo1(-/-) knockout mice, in the present study we show that [a] NQO1 protein locates to cytosol, ER and mitochondria, [b] CYP1B1 protein (similar to CYP1A1 and CYP1A2 proteins) traffics to mitochondria as well as ER, and [c] NQO1 and CYP1B1 targeting to mitochondrial or ER membranes is independent of CYP1A1 presence in that membrane.
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Affiliation(s)
- Hongbin Dong
- Department of Environmental Health and Center for Environmental Genetics, University Cincinnati Medical Center, Cincinnati, OH 45267-0056, USA
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