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Maier MLV, Siddens LK, Pennington JM, Uesugi SL, Labut EM, Vertel EA, Anderson KA, Tidwell LG, Tilton SC, Ognibene TJ, Turteltaub KW, Smith JN, Williams DE. Impact of phenanthrene co-administration on the toxicokinetics of benzo[a]pyrene in humans. UPLC-accelerator mass spectrometry following oral microdosing. Chem Biol Interact 2023; 382:110608. [PMID: 37369263 PMCID: PMC10782561 DOI: 10.1016/j.cbi.2023.110608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 06/13/2023] [Accepted: 06/16/2023] [Indexed: 06/29/2023]
Abstract
Current risk assessments for environmental carcinogens rely on animal studies utilizing doses orders of magnitude higher than actual human exposures. Epidemiological studies of people with high exposures (e.g., occupational) are of value, but rely on uncertain exposure data. In addition, exposures are typically not to a single chemical but to mixtures, such as polycyclic aromatic hydrocarbons (PAHs). The extremely high sensitivity of accelerator mass spectrometry (AMS) allows for dosing humans with known carcinogens with de minimus risk. In this study UPLC-AMS was used to assess the toxicokinetics of [14C]-benzo[a]pyrene ([14C]-BaP) when dosed alone or in a binary mixture with phenanthrene (Phe). Plasma was collected for 48 h following a dose of [14C]-BaP (50 ng, 5.4 nCi) or the same dose of [14C]-BaP plus Phe (1250 ng). Following the binary mixture, Cmax of [14C]-BaP significantly decreased (4.4-fold) whereas the volume of distribution (Vd) increased (2-fold). Further, the toxicokinetics of twelve [14C]-BaP metabolites provided evidence of little change in the metabolite profile of [14C]-BaP and the pattern was overall reduction consistent with reduced absorption (decrease in Cmax). Although Phe was shown to be a competitive inhibitor of the major hepatic cytochrome P-450 (CYP) responsible for metabolism of [14C]-BaP, CYP1A2, the high inhibition constant (Ki) and lack of any increase in unmetabolized [14C]-BaP in plasma makes this mechanism unlikely to be responsible. Rather, co-administration of Phe reduces the absorption of [14C]-BaP through a mechanism yet to be determined. This is the first study to provide evidence that, at actual environmental levels of exposure, the toxicokinetics of [14C]-BaP in humans is markedly altered by the presence of a second PAH, Phe, a common component of environmental PAH mixtures.
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Affiliation(s)
- Monica L Vermillion Maier
- Linus Pauling Institute, Oregon State University, Corvallis, OR, 97331, USA; Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR, 97331, USA.
| | - Lisbeth K Siddens
- Linus Pauling Institute, Oregon State University, Corvallis, OR, 97331, USA; Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR, 97331, USA.
| | - Jamie M Pennington
- Linus Pauling Institute, Oregon State University, Corvallis, OR, 97331, USA; Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR, 97331, USA.
| | - Sandra L Uesugi
- Linus Pauling Institute, Oregon State University, Corvallis, OR, 97331, USA.
| | - Edwin M Labut
- Linus Pauling Institute, Oregon State University, Corvallis, OR, 97331, USA.
| | - Emily A Vertel
- Linus Pauling Institute, Oregon State University, Corvallis, OR, 97331, USA.
| | - Kim A Anderson
- Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR, 97331, USA; NIEHS Superfund Research Program, Oregon State University, Corvallis, OR, 97331, USA.
| | - Lane G Tidwell
- Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR, 97331, USA.
| | - Susan C Tilton
- Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR, 97331, USA; NIEHS Superfund Research Program, Oregon State University, Corvallis, OR, 97331, USA.
| | - Ted J Ognibene
- Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA.
| | - Kenneth W Turteltaub
- Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA; Biology and Biotechnology Research Division, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA.
| | - Jordan N Smith
- NIEHS Superfund Research Program, Oregon State University, Corvallis, OR, 97331, USA; Chemical Biology and Exposure Science, Pacific Northwest National Laboratory, Richland, WA, 99354, USA.
| | - David E Williams
- Linus Pauling Institute, Oregon State University, Corvallis, OR, 97331, USA; Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR, 97331, USA; NIEHS Superfund Research Program, Oregon State University, Corvallis, OR, 97331, USA
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2
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Dong H, Kong X, Wang X, Liu Q, Fang Y, Wang J. The Causal Effect of Dietary Composition on the Risk of Breast Cancer: A Mendelian Randomization Study. Nutrients 2023; 15:nu15112586. [PMID: 37299548 DOI: 10.3390/nu15112586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Revised: 05/24/2023] [Accepted: 05/26/2023] [Indexed: 06/12/2023] Open
Abstract
Breast cancer has become the most common malignancy among women, posing a severe health risk to women worldwide and creating a heavy social burden. Based on current observational studies, the dietary factor may have a causal relationship with breast cancer. Therefore, exploring how dietary composition affects breast cancer incidence will provide nutrition strategies for clinicians and women. We performed a two-sample Mendelian randomization (MR) analysis to find the causal effect of four kinds of relative macronutrient intake (protein, carbohydrate, sugar, and fat) on the risk of breast cancer and its subtypes [Luminal A, Luminal B, Luminal B HER2-negative, HER2-positive, Triple-negative, Estrogen receptor (ER) positive, and ER-negative breast cancer]. The Mendelian randomization pleiotropy residual sum and outlier (MR-PRESSO) test, MR-Egger intercept test, Cochran's Q statistic, funnel plot, and leave-one-out (Loo) analysis were all used in a sensitivity analysis to test the robustness of MR. Genetically, a higher relative protein intake was found as a protective factor for Luminal A and overall breast cancer, which was inconsistent with recent findings. A higher relative sugar intake could genetically promote the risk of Luminal B and HER2-positive breast cancer. Conclusions: A higher protein proportion in diet genetically reduces the risk of breast cancer, while higher relative sugar intake does the opposite.
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Affiliation(s)
- Hao Dong
- National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, China
| | - Xiangyi Kong
- National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, China
| | - Xiangyu Wang
- National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, China
| | - Qiang Liu
- National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, China
| | - Yi Fang
- National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, China
| | - Jing Wang
- National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, China
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Vermillion Maier ML, Siddens LK, Pennington JM, Uesugi SL, Tilton SC, Vertel EA, Anderson KA, Tidwell LG, Ognibene TJ, Turteltaub KW, Smith JN, Williams DE. Benzo[a]pyrene toxicokinetics in humans following dietary supplementation with 3,3'-diindolylmethane (DIM) or Brussels sprouts. Toxicol Appl Pharmacol 2023; 460:116377. [PMID: 36642108 PMCID: PMC9946811 DOI: 10.1016/j.taap.2023.116377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 01/05/2023] [Accepted: 01/09/2023] [Indexed: 01/15/2023]
Abstract
Utilizing the atto-zeptomole sensitivity of UPLC-accelerator mass spectrometry (UPLC-AMS), we previously demonstrated significant first-pass metabolism following escalating (25-250 ng) oral micro-dosing in humans of [14C]-benzo[a]pyrene ([14C]-BaP). The present study examines the potential for supplementation with Brussels sprouts (BS) or 3,3'-diindolylmethane (DIM) to alter plasma levels of [14C]-BaP and metabolites over a 48-h period following micro-dosing with 50 ng (5.4 nCi) [14C]-BaP. Volunteers were dosed with [14C]-BaP following fourteen days on a cruciferous vegetable restricted diet, or the same diet supplemented for seven days with 50 g of BS or 300 mg of BR-DIM® prior to dosing. BS or DIM reduced total [14C] recovered from plasma by 56-67% relative to non-intervention. Dietary supplementation with DIM markedly increased Tmax and reduced Cmax for [14C]-BaP indicative of slower absorption. Both dietary treatments significantly reduced Cmax values of four downstream BaP metabolites, consistent with delaying BaP absorption. Dietary treatments also appeared to reduce the T1/2 and the plasma AUC(0,∞) for Unknown Metabolite C, indicating some effect in accelerating clearance of this metabolite. Toxicokinetic constants for other metabolites followed the pattern for [14C]-BaP (metabolite profiles remained relatively consistent) and non-compartmental analysis did not indicate other significant alterations. Significant amounts of metabolites in plasma were at the bay region of [14C]-BaP irrespective of treatment. Although the number of subjects and large interindividual variation are limitations of this study, it represents the first human trial showing dietary intervention altering toxicokinetics of a defined dose of a known human carcinogen.
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Affiliation(s)
- Monica L Vermillion Maier
- Linus Pauling Institute, Oregon State University, Corvallis, OR 97331, USA; Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97331, USA; Department of Environmental and Molecular Toxicology, ALS 1007, Oregon State University, Corvallis, OR 97331, USA.
| | - Lisbeth K Siddens
- Linus Pauling Institute, Oregon State University, Corvallis, OR 97331, USA; Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97331, USA.
| | - Jamie M Pennington
- Linus Pauling Institute, Oregon State University, Corvallis, OR 97331, USA; Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97331, USA.
| | - Sandra L Uesugi
- Linus Pauling Institute, Oregon State University, Corvallis, OR 97331, USA.
| | - Susan C Tilton
- Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97331, USA; NIEHS Superfund Research Program, Oregon State University, Corvallis, OR 97331, USA.
| | - Emily A Vertel
- Linus Pauling Institute, Oregon State University, Corvallis, OR 97331, USA; Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97331, USA.
| | - Kim A Anderson
- Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97331, USA; NIEHS Superfund Research Program, Oregon State University, Corvallis, OR 97331, USA.
| | - Lane G Tidwell
- Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97331, USA.
| | - Ted J Ognibene
- Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA.
| | - Kenneth W Turteltaub
- Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA; Biology and Biotechnology Research Division, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA.
| | - Jordan N Smith
- NIEHS Superfund Research Program, Oregon State University, Corvallis, OR 97331, USA; Chemical Biology and Exposure Science, Pacific Northwest National Laboratory, Richland, WA 99354, USA.
| | - David E Williams
- Linus Pauling Institute, Oregon State University, Corvallis, OR 97331, USA; Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97331, USA; NIEHS Superfund Research Program, Oregon State University, Corvallis, OR 97331, USA.
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Bellamri M, Walmsley SJ, Turesky RJ. Metabolism and biomarkers of heterocyclic aromatic amines in humans. Genes Environ 2021; 43:29. [PMID: 34271992 PMCID: PMC8284014 DOI: 10.1186/s41021-021-00200-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 06/27/2021] [Indexed: 12/15/2022] Open
Abstract
Heterocyclic aromatic amines (HAAs) form during the high-temperature cooking of meats, poultry, and fish. Some HAAs also arise during the combustion of tobacco. HAAs are multisite carcinogens in rodents, inducing cancer of the liver, gastrointestinal tract, pancreas, mammary, and prostate glands. HAAs undergo metabolic activation by N-hydroxylation of the exocyclic amine groups to produce the proposed reactive intermediate, the heteroaryl nitrenium ion, which is the critical metabolite implicated in DNA damage and genotoxicity. Humans efficiently convert HAAs to these reactive intermediates, resulting in HAA protein and DNA adduct formation. Some epidemiologic studies have reported an association between frequent consumption of well-done cooked meats and elevated cancer risk of the colorectum, pancreas, and prostate. However, other studies have reported no associations between cooked meat and these cancer sites. A significant limitation in epidemiology studies assessing the role of HAAs and cooked meat in cancer risk is their reliance on food frequency questionnaires (FFQ) to gauge HAA exposure. FFQs are problematic because of limitations in self-reported dietary history accuracy, and estimating HAA intake formed in cooked meats at the parts-per-billion level is challenging. There is a critical need to establish long-lived biomarkers of HAAs for implementation in molecular epidemiology studies designed to assess the role of HAAs in health risk. This review article highlights the mechanisms of HAA formation, mutagenesis and carcinogenesis, the metabolism of several prominent HAAs, and the impact of critical xenobiotic-metabolizing enzymes on biological effects. The analytical approaches that have successfully biomonitored HAAs and their biomarkers for molecular epidemiology studies are presented.
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Affiliation(s)
- Medjda Bellamri
- Masonic Cancer Center and Department of Medicinal Chemistry, Cancer and Cardiovascular Research Building, University of Minnesota, 2231 6th Street, Minneapolis, MN, 55455, USA.,Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Scott J Walmsley
- Masonic Cancer Center and Department of Medicinal Chemistry, Cancer and Cardiovascular Research Building, University of Minnesota, 2231 6th Street, Minneapolis, MN, 55455, USA.,Institute of Health Informatics, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Robert J Turesky
- Masonic Cancer Center and Department of Medicinal Chemistry, Cancer and Cardiovascular Research Building, University of Minnesota, 2231 6th Street, Minneapolis, MN, 55455, USA. .,Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, Minneapolis, MN, 55455, USA.
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Lawana V, Um SY, Rochet JC, Turesky RJ, Shannahan JH, Cannon JR. Neuromelanin Modulates Heterocyclic Aromatic Amine-Induced Dopaminergic Neurotoxicity. Toxicol Sci 2021; 173:171-188. [PMID: 31562763 DOI: 10.1093/toxsci/kfz210] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Heterocyclic aromatic amines (HAAs) are mutagens and potential human carcinogens. Our group and others have demonstrated that HAAs may also produce selective dopaminergic neurotoxicity, potentially relevant to Parkinson's disease (PD). The goal of this study was to elucidate mechanisms of HAA-induced neurotoxicity through examining a translational biochemical weakness of common PD models. Neuromelanin is a pigmented byproduct of dopamine metabolism that has been debated as being both neurotoxic and neuroprotective in PD. Importantly, neuromelanin is known to bind and potentially release dopaminergic neurotoxicants, including HAAs (eg, β-carbolines such as harmane). Binding of other HAA subclasses (ie, aminoimidazoaazarenes) to neuromelanin has not been investigated, nor has a specific role for neuromelanin in mediating HAA-induced neurotoxicity been examined. Thus, we investigated the role of neuromelanin in modulating HAA-induced neurotoxicity. We characterized melanin from Sepia officinalis and synthetic dopamine melanin, proposed neuromelanin analogs with similar biophysical properties. Using a cell-free assay, we demonstrated strong binding of harmane and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) to neuromelanin analogs. To increase cellular neuromelanin, we transfected SH-SY5Y neuroblastoma cells with tyrosinase. Relative to controls, tyrosinase-expressing cells exhibited increased neuromelanin levels, cellular HAA uptake, cell toxicity, and oxidative damage. Given that typical cellular and rodent PD models form far lower neuromelanin levels than humans, there is a critical translational weakness in assessing HAA-neurotoxicity. The primary impacts of these results are identification of a potential mechanism by which HAAs accumulate in catecholaminergic neurons and support for the need to conduct neurotoxicity studies in systems forming neuromelanin.
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Affiliation(s)
- Vivek Lawana
- School of Health Sciences.,Purdue Institute for Integrative Neuroscience
| | | | - Jean-Christophe Rochet
- Purdue Institute for Integrative Neuroscience.,Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana 47907
| | - Robert J Turesky
- Department of Medicinal Chemistry, Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota 55455
| | | | - Jason R Cannon
- School of Health Sciences.,Purdue Institute for Integrative Neuroscience
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6
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Syeda T, Foguth RM, Llewellyn E, Cannon JR. PhIP exposure in rodents produces neuropathology potentially relevant to Alzheimer's disease. Toxicology 2020; 437:152436. [PMID: 32169473 PMCID: PMC7218929 DOI: 10.1016/j.tox.2020.152436] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 03/01/2020] [Accepted: 03/09/2020] [Indexed: 12/31/2022]
Abstract
Alzheimer's disease (AD) is a public health crisis due to debilitating cognitive symptoms and lack of curative treatments, in the context of increasing prevalence. Thus, it is critical to identify modifiable risk factors. High levels of meat consumption may increase AD risk. Many toxins are formed during meat cooking such as heterocyclic aromatic amines (HAAs). Our prior studies have shown that HAAs produce dopaminergic neurotoxicity. Given the mechanistic and pathological overlap between AD and dopaminergic disorders we investigated whether exposure to 2-amino-1-methyl-6-phenylimidazo [4,5-b] pyridine (PhIP), a prevalent dietary HAA formed during high-temperature meat cooking, may produce AD-relevant neurotoxicity. Here, C57BL/6 mice were treated with 100 or 200 mg/kg PhIP for 8 h or 75 mg/kg for 4 weeks and 16 weeks. PhIP exposure for 8 h produced oxidative damage, and AD-relevant alterations in hippocampal synaptic proteins, Amyloid-beta precursor protein (APP), and β-Site amyloid precursor protein cleaving enzyme 1 (BACE1). PhIP exposure for 4 weeks resulted in an increase in BACE1. PhIP exposure for 16 weeks resulted in increased hippocampal oxidative damage, APP, BACE1, Aβ aggregation, and tau phosphorylation. Quantification of intracellular nitrotyrosine revealed oxidative damage in cholinergic neurons after 8 h, 4 weeks and 16 weeks of PhIP exposure. Our study demonstrates that increase in oxidative damage, APP and BACE1 might be a possible mechanism by which PhIP promotes Aβ aggregation. Given many patients with AD or PD exhibit neuropathological overlap, our study suggests that HAA exposure should be further studied for roles in mediating pathogenic overlap.
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Affiliation(s)
- Tauqeerunnisa Syeda
- School of Health Sciences, Purdue University, West Lafayette, IN, 47907, United States; Purdue Institute for Integrative Neurosciences, Purdue University, West Lafayette, IN, 47907, United States
| | - Rachel M Foguth
- School of Health Sciences, Purdue University, West Lafayette, IN, 47907, United States; Purdue Institute for Integrative Neurosciences, Purdue University, West Lafayette, IN, 47907, United States
| | - Emily Llewellyn
- Summer Research Opportunities Program, Purdue, University, West Lafayette, IN, 47907, United States; Department of Biology, Utah Valley University, Orem, Utah, 84058, United States
| | - Jason R Cannon
- School of Health Sciences, Purdue University, West Lafayette, IN, 47907, United States; Purdue Institute for Integrative Neurosciences, Purdue University, West Lafayette, IN, 47907, United States.
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Kapelyukh Y, Henderson CJ, Scheer N, Rode A, Wolf CR. Defining the Contribution of CYP1A1 and CYP1A2 to Drug Metabolism Using Humanized CYP1A1/1A2 and Cyp1a1/Cyp1a2 Knockout Mice. Drug Metab Dispos 2019; 47:907-918. [PMID: 31147315 PMCID: PMC6657216 DOI: 10.1124/dmd.119.087718] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Accepted: 05/28/2019] [Indexed: 12/16/2022] Open
Abstract
Cytochrome P450s CYP1A1 and CYP1A2 can metabolize a broad range of foreign compounds and drugs. However, these enzymes have significantly overlapping substrate specificities. To establish their relative contribution to drug metabolism in vivo, we used a combination of mice humanized for CYP1A1 and CYP1A2 together with mice nulled at the Cyp1a1 and Cyp1a2 gene loci. CYP1A2 was constitutively expressed in the liver, and both proteins were highly inducible by 2,3,7,8-tetrachlorodibenzodioxin (TCDD) in a number of tissues, including the liver, lung, kidney, and small intestine. Using the differential inhibition of the human enzymes by quinidine, we developed a method to distinguish the relative contribution of CYP1A1 or CYP1A2 in the metabolism of drugs and foreign compounds. Both enzymes made a significant contribution to the hepatic metabolism of the probe compounds 7-methoxy and 7-ehthoxyresorufin in microsomal fractions from animals treated with TCDD. This enzyme kinetic approach allows modeling of the CYP1A1, CYP1A2, and non-CYP1A contribution to the metabolism of any substrate at any substrate, inhibitor, or enzyme concentration and, as a consequence, can be integrated into a physiologically based pharmacokinetics model. The validity of the model can then be tested in humanized mice in vivo. SIGNIFICANCE STATEMENT: Human CYP1A1 and CYP1A2 are important in defining the efficacy and toxicity/carcinogenicity of drugs and foreign compounds. In light of differences in substrate specificity and sensitivity to inhibitors, it is of central importance to understand their relative role in foreign compound metabolism. To address this issue, we have generated mice humanized or nulled at the Cyp1a gene locus and, through the use of these mouse lines and selective inhibitors, developed an enzyme kinetic-based model to enable more accurate prediction of the fate of new chemicals in humans and which can be validated in vivo using mice humanized for cytochrome P450-mediated metabolism.
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Affiliation(s)
- Y Kapelyukh
- Systems Medicine, School of Medicine, University of Dundee, Jacqui Wood Cancer Centre, Ninewells Hospital, Dundee, United Kingdom (Y.K., C.J.H., C.R.W.) and Taconic Biosciences Inc., Rensselaer, New York (N.S., A.R.)
| | - C J Henderson
- Systems Medicine, School of Medicine, University of Dundee, Jacqui Wood Cancer Centre, Ninewells Hospital, Dundee, United Kingdom (Y.K., C.J.H., C.R.W.) and Taconic Biosciences Inc., Rensselaer, New York (N.S., A.R.)
| | - N Scheer
- Systems Medicine, School of Medicine, University of Dundee, Jacqui Wood Cancer Centre, Ninewells Hospital, Dundee, United Kingdom (Y.K., C.J.H., C.R.W.) and Taconic Biosciences Inc., Rensselaer, New York (N.S., A.R.)
| | - A Rode
- Systems Medicine, School of Medicine, University of Dundee, Jacqui Wood Cancer Centre, Ninewells Hospital, Dundee, United Kingdom (Y.K., C.J.H., C.R.W.) and Taconic Biosciences Inc., Rensselaer, New York (N.S., A.R.)
| | - C R Wolf
- Systems Medicine, School of Medicine, University of Dundee, Jacqui Wood Cancer Centre, Ninewells Hospital, Dundee, United Kingdom (Y.K., C.J.H., C.R.W.) and Taconic Biosciences Inc., Rensselaer, New York (N.S., A.R.)
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8
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ABC transporters Mdr1a/1b, Bcrp1, Mrp2 and Mrp3 determine the sensitivity to PhIP/DSS-induced colon carcinogenesis and inflammation. Arch Toxicol 2019; 93:775-790. [DOI: 10.1007/s00204-019-02394-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 01/10/2019] [Indexed: 12/29/2022]
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Enerstvedt KS, Sydnes MO, Larssen E, Pampanin DM. Screening for protein adducts of naphthalene and chrysene in plasma of exposed Atlantic cod (Gadus morhua). CHEMOSPHERE 2018; 200:67-79. [PMID: 29475030 DOI: 10.1016/j.chemosphere.2018.02.091] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 02/14/2018] [Accepted: 02/15/2018] [Indexed: 06/08/2023]
Abstract
Polycyclic aromatic hydrocarbons (PAHs) are well known contaminants, ubiquitously present in the habitat and spawning areas for Atlantic cod (Gadus morhua). The Atlantic cod is a key species and a globally important food source, thus continuous monitoring of PAHs is considered highly valuable to ensure ecosystem sustainability and human food safety. PAH adducts to plasma proteins are applied as sensitive biomarkers of PAH exposure in humans and other species, thus the presence of PAH protein adducts in Atlantic cod plasma was investigated to identify PAH protein adduct biomarker candidates of exposure to PAHs. Blood plasma samples were collected from Atlantic cod (n = 66) one week after exposure by intramuscular injection of single PAHs (i.e. naphthalene and chrysene), and their corresponding dihydrodiol metabolites (i.e. (-)-(1R,2R)-1,2-dihydronaphthalene-1,2-diol and (-)-(1R,2R)-1,2-dihydrochrysene-1,2-diol). The samples were analyzed by shotgun tandem mass spectrometry (MS) and the resulting MS data were analyzed in Byonic™ to screen for proteins susceptible to adduct formation with naphthalene and chrysene. Furthermore, a wildcard modification search was performed to obtain additional information regarding potential modifications other than the targeted metabolites. The amino acid adductation sites and the metabolites involved in PAH adductation are reported. Forty-four proteins were found to bind PAHs. Alpha-2-macroglobulin-like proteins, apolipoproteins B-100-like proteins and an alpha-2-HS-glycoprotein were detected with the highest number of bound PAHs. This first insight into PAH protein adducts of Atlantic cod plasma generates valuable knowledge for the development of highly sensitive biomarkers of PAH exposure.
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Affiliation(s)
- Karianne S Enerstvedt
- International Research Institute of Stavanger (IRIS) - Environment Department, Mekjarvik 12, NO-4070 Randaberg, Norway; Faculty of Science and Technology, Department of Mathematics and Natural Science, University of Stavanger, NO-4036 Stavanger, Norway
| | - Magne O Sydnes
- Faculty of Science and Technology, Department of Mathematics and Natural Science, University of Stavanger, NO-4036 Stavanger, Norway
| | - Eivind Larssen
- International Research Institute of Stavanger (IRIS) - Environment Department, Mekjarvik 12, NO-4070 Randaberg, Norway
| | - Daniela M Pampanin
- International Research Institute of Stavanger (IRIS) - Environment Department, Mekjarvik 12, NO-4070 Randaberg, Norway; Faculty of Science and Technology, Department of Mathematics and Natural Science, University of Stavanger, NO-4036 Stavanger, Norway.
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10
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Enright HA, Malfatti MA, Zimmermann M, Ognibene T, Henderson P, Turteltaub KW. Use of Accelerator Mass Spectrometry in Human Health and Molecular Toxicology. Chem Res Toxicol 2016; 29:1976-1986. [PMID: 27726383 PMCID: PMC5203773 DOI: 10.1021/acs.chemrestox.6b00234] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Accelerator mass spectrometry (AMS) has been adopted as a powerful bioanalytical method for human studies in the areas of pharmacology and toxicology. The exquisite sensitivity (10-18 mol) of AMS has facilitated studies of toxins and drugs at environmentally and physiologically relevant concentrations in humans. Such studies include risk assessment of environmental toxicants, drug candidate selection, absolute bioavailability determination, and more recently, assessment of drug-target binding as a biomarker of response to chemotherapy. Combining AMS with complementary capabilities such as high performance liquid chromatography (HPLC) can maximize data within a single experiment and provide additional insight when assessing drugs and toxins, such as metabolic profiling. Recent advances in the AMS technology at Lawrence Livermore National Laboratory have allowed for direct coupling of AMS with complementary capabilities such as HPLC via a liquid sample moving wire interface, offering greater sensitivity compared to that of graphite-based analysis, therefore enabling the use of lower 14C and chemical doses, which are imperative for clinical testing. The aim of this review is to highlight the recent efforts in human studies using AMS, including technological advancements and discussion of the continued promise of AMS for innovative clinical based research.
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Affiliation(s)
- Heather A. Enright
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA USA
| | - Michael A. Malfatti
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA USA
| | - Maike Zimmermann
- Department of Internal Medicine, Division of Hematology and Oncology, UC Davis Medical Center, Sacramento, CA USA
- Accelerated Medical Diagnostics Incorporated, Berkeley, CA USA
| | - Ted Ognibene
- Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, Livermore, CA USA
| | - Paul Henderson
- Department of Internal Medicine, Division of Hematology and Oncology, UC Davis Medical Center, Sacramento, CA USA
- Accelerated Medical Diagnostics Incorporated, Berkeley, CA USA
| | - Kenneth W. Turteltaub
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA USA
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11
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Pathak KV, Chiu TL, Amin EA, Turesky RJ. Methemoglobin Formation and Characterization of Hemoglobin Adducts of Carcinogenic Aromatic Amines and Heterocyclic Aromatic Amines. Chem Res Toxicol 2016; 29:255-69. [PMID: 26824300 PMCID: PMC4801648 DOI: 10.1021/acs.chemrestox.5b00418] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Arylamines (AAs) and heterocyclic aromatic amines (HAAs) are structurally related carcinogens formed during the combustion of tobacco or cooking of meat. They undergo cytochrome P450 mediated N-hydroxylation to form metabolites which bind to DNA and lead to mutations. The N-hydroxylated metabolites of many AAs also can undergo a co-oxidation reaction with oxy-hemolgobin (HbO2) to form methemoglobin (met-Hb) and the arylnitroso intermediates, which react with the β-Cys(93) chain of Hb to form Hb-arylsulfinamide adducts. The biochemistry of arylamine metabolism has been exploited to biomonitor certain AAs through their Hb arylsulfinamide adducts in humans. We examined the reactivity of HbO2 with the N-hydroxylated metabolites of 4-aminobiphenyl (ABP, HONH-ABP), aniline (ANL, HONH-ANL), and the HAAs 2-amino-9H-pyrido[2,3-b]indole (AαC, HONH-AαC), 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP, HONH-PhIP), and 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx, HONH-MeIQx). HONH-ABP, HO-ANL, and HONH-AαC induced methemoglobinemia and formed Hb sulfinamide adducts. However, HONH-MeIQx and HONH-PhIP did not react with the oxy-heme complex, and met-Hb formation and chemical modification of the β-Cys(93) residue were negligible. Molecular modeling studies showed that the distances between the H-ON-AA or H-ON-HAA substrates and the oxy-heme complex of HbO2 were too far away to induce methemoglobinemia. Different conformational changes in flexible helical and loop regions around the heme pocket induced by the H-ON-AA or H-ON-HAAs may explain the different proclivities of these chemicals to induce methemoglobinemia. Hb-Cys(93β) sulfinamide and sulfonamide adducts of ABP, ANL, and AαC were identified, by Orbitrap MS, following the proteolysis of Hb with trypsin, Glu-C, or Lys-C. Hb sulfinamide and sulfonamide adducts of ABP were identified in the blood of mice exposed to ABP, by Orbitrap MS. This is the first report of the identification of intact Hb sulfinamide adducts of carcinogenic AAs in vivo. The high reactivity of HONH-AαC with HbO2 suggests that the Hb sulfinamide adduct of AαC may be a promising biomarker of exposure to this HAA in humans.
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Affiliation(s)
| | - Ting-Lan Chiu
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455, USA
| | | | - Robert J. Turesky
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455, USA
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455, USA
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12
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Gibis M, Weiss J. Impact of Precursors Creatine, Creatinine, and Glucose on the Formation of Heterocyclic Aromatic Amines in Grilled Patties of Various Animal Species. J Food Sci 2015; 80:C2430-9. [DOI: 10.1111/1750-3841.13090] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 08/24/2015] [Indexed: 11/28/2022]
Affiliation(s)
- Monika Gibis
- Dept. of Food Physics and Meat Science, Inst. of Food Science and Biotechnology; Univ. of Hohenheim; Garbenstrasse 21/25 70599 Stuttgart Germany
| | - Jochen Weiss
- Dept. of Food Physics and Meat Science, Inst. of Food Science and Biotechnology; Univ. of Hohenheim; Garbenstrasse 21/25 70599 Stuttgart Germany
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13
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Jain A, Samykutty A, Jackson C, Browning D, Bollag WB, Thangaraju M, Takahashi S, Singh SR. Curcumin inhibits PhIP induced cytotoxicity in breast epithelial cells through multiple molecular targets. Cancer Lett 2015; 365:122-31. [PMID: 26004342 DOI: 10.1016/j.canlet.2015.05.017] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 05/13/2015] [Accepted: 05/14/2015] [Indexed: 12/21/2022]
Abstract
Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), found in cooked meat, is a known food carcinogen that causes several types of cancer, including breast cancer, as PhIP metabolites produce DNA adduct and DNA strand breaks. Curcumin, obtained from the rhizome of Curcuma longa, has potent anticancer activity. To date, no study has examined the interaction of PhIP with curcumin in breast epithelial cells. The present study demonstrates the mechanisms by which curcumin inhibits PhIP-induced cytotoxicity in normal breast epithelial cells (MCF-10A). Curcumin significantly inhibited PhIP-induced DNA adduct formation and DNA double stand breaks with a concomitant decrease in reactive oxygen species (ROS) production. The expression of Nrf2, FOXO targets; DNA repair genes BRCA-1, H2AFX and PARP-1; and tumor suppressor P16 was studied to evaluate the influence on these core signaling pathways. PhIP induced the expression of various antioxidant and DNA repair genes. However, co-treatment with curcumin inhibited this expression. PhIP suppressed the expression of the tumor suppressor P16 gene, whereas curcumin co-treatment increased its expression. Caspase-3 and -9 were slightly suppressed by curcumin with a consequent inhibition of cell death. These results suggest that curcumin appears to be an effective anti-PhIP food additive likely acting through multiple molecular targets.
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Affiliation(s)
- Ashok Jain
- Department of Natural Sciences, Albany State University, Albany, Georgia 31705, USA.
| | - Abhilash Samykutty
- Department of Natural Sciences, Albany State University, Albany, Georgia 31705, USA
| | - Carissa Jackson
- Department of Natural Sciences, Albany State University, Albany, Georgia 31705, USA
| | - Darren Browning
- Cancer Center, Georgia Regents University, Augusta, Georgia 30912, USA
| | - Wendy B Bollag
- Department of Physiology, Georgia Regents University, Augusta, Georgia 30912, USA; Charlie Norwood VA Medical Center, Augusta, Georgia 30904, USA
| | | | - Satoru Takahashi
- Department of Experimental Pathology and Tumor Biology, Graduate School of Medical Sciences, Nagoya City University, Nagoya 467-8601, Japan
| | - Shree Ram Singh
- Basic Research Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland, USA.
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14
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Ho V, Peacock S, Massey TE, Ashbury JE, Vanner SJ, King WD. Meat-derived carcinogens, genetic susceptibility and colorectal adenoma risk. GENES AND NUTRITION 2014; 9:430. [PMID: 25231222 DOI: 10.1007/s12263-014-0430-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Accepted: 09/06/2014] [Indexed: 01/30/2023]
Abstract
Exposure to heterocyclic aromatic amines (HAAs), carcinogens produced when meat is cooked at high temperatures, is an emerging risk factor for colorectal cancer (CRC). In a cross-sectional study of 342 patients undergoing a screening colonoscopy, the role of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) and 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (DiMeIQx), the three most abundant HAAs found in cooked meats, and total mutagenic activity in cooked meats were examined in relation to colorectal adenoma risk. Given that genetic differences in the ability to biotransform HAAs and repair DNA are postulated to modify the HAA-CRC relationship, gene-diet interactions were also examined. Among the total study population, no relationships were observed between dietary HAAs or meat mutagenicity, and colorectal adenoma risk; however, in males, positive associations between dietary HAAs/meat mutagenicity exposures and adenoma risk were suggestive of a relationship. In a separate analysis, polymorphisms in CYP1B1 were found to be associated with colorectal adenoma risk. Additionally, gene-diet interactions were observed for dietary PhIP and polymorphisms in CYP1B1 and XPD, dietary DiMeIQx and XPD polymorphisms, and meat mutagenicity exposure and CYP1B1 polymorphisms. Overall, increased colorectal adenoma risk was observed with higher HAA/meat mutagenicity exposures among those with polymorphisms which confer greater activity to biotransform HAAs and/or lower ability to repair DNA. This research supports the link between dietary HAAs and genetic susceptibility in colorectal adenoma etiology. The vast majority of CRCs arise from colorectal adenomas; thus, the results of this study suggest that changes in meat preparation practices limiting the production of HAAs may be beneficial for CRC prevention.
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Affiliation(s)
- Vikki Ho
- University of Montreal Hospital Research Centre (CRCHUM), Montreal, QC, H2X 0A9, Canada,
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15
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Papaioannou MD, Koufaris C, Gooderham NJ. The cooked meat-derived mammary carcinogen 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) elicits estrogenic-like microRNA responses in breast cancer cells. Toxicol Lett 2014; 229:9-16. [PMID: 24877718 DOI: 10.1016/j.toxlet.2014.05.021] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 05/23/2014] [Accepted: 05/26/2014] [Indexed: 01/08/2023]
Abstract
The cooking of meat results in the generation of heterocyclic amines (HCA), the most abundant of which is 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP). Data from epidemiological, mechanistic, and animal studies indicate that PhIP could be causally linked to breast cancer incidence. Besides the established DNA damaging and mutagenic activities of PhIP, the chemical is reported to have oestrogenic activity that could contribute to its tissue specific carcinogenicity. In this study we investigated the effect of treatment with PhIP and 17-β-estradiol (E2) on global microRNA (miRNA) expression of the oestrogen responsive MCF-7 human breast adenocarcinoma cell line. PhIP and E2 caused widespread and largely over-lapping effects on miRNA expression, with many of the commonly affected miRNA reported to be regulated by oestrogen and have been implicated in the initiation and progression of breast cancer. The regulatory activity of the miRNAs we show here to be responsive to PhIP treatment, are also predicted to mediate cellular phenotypes that are associated with PhIP exposure. Consequently, this study offers further support to the ability of PhIP to induce widespread effects via activation of oestrogen receptor alpha (ERα). Moreover, this study indicates that deregulation of miRNA by PhIP could potentially be an important non-DNA-damaging carcinogenic mechanism in breast cancer.
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Affiliation(s)
- M D Papaioannou
- Computational and Systems Medicine, Surgery and Cancer, Imperial College London SW7 2AZ, UK
| | - C Koufaris
- Computational and Systems Medicine, Surgery and Cancer, Imperial College London SW7 2AZ, UK
| | - N J Gooderham
- Computational and Systems Medicine, Surgery and Cancer, Imperial College London SW7 2AZ, UK.
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16
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Griggs AM, Agim ZS, Mishra VR, Tambe MA, Director-Myska AE, Turteltaub KW, McCabe GP, Rochet JC, Cannon JR. 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is selectively toxic to primary dopaminergic neurons in vitro. Toxicol Sci 2014; 140:179-89. [PMID: 24718704 DOI: 10.1093/toxsci/kfu060] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Parkinson's disease (PD) is the second most common neurodegenerative disease. Much data has linked the etiology of PD to a variety of environmental factors. The majority of cases are thought to arise from a combination of genetic susceptibility and environmental factors. Chronic exposures to dietary factors, including meat, have been identified as potential risk factors. Although heterocyclic amines that are produced during high-temperature meat cooking are known to be carcinogenic, their effect on the nervous system has yet to be studied in depth. In this study, we investigated neurotoxic effects of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), a highly abundant heterocyclic amine in cooked meat, in vitro. We tested toxicity of PhIP and the two major phase I metabolites, N-OH-PhIP and 4'-OH-PhIP, using primary mesencephalic cultures from rat embryos. This culture system contains both dopaminergic and nondopaminergic neurons, which allows specificity of neurotoxicity to be readily examined. We find that exposure to PhIP or N-OH-PhIP is selectively toxic to dopaminergic neurons in primary cultures, resulting in a decreased percentage of dopaminergic neurons. Neurite length is decreased in surviving dopaminergic neurons. Exposure to 4'-OH-PhIP did not produce significant neurotoxicity. PhIP treatment also increased formation of oxidative damage markers, 4-hydroxy-2-nonenal (HNE) and 3-nitrotyrosine in dopaminergic neurons. Pretreatment with N-acetylcysteine was protective. Finally, treatment with blueberry extract, a dietary factor with known antioxidant and other protective mechanisms, prevented PhIP-induced toxicity. Collectively, our study suggests, for the first time, that PhIP is selectively toxic to dopaminergic neurons likely through inducing oxidative stress.
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Affiliation(s)
- Amy M Griggs
- School of Health Sciences, Purdue University, West Lafayette, Indiana 47907 Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana 47907 Cook MED Institute, West Lafayette, Indiana 47906
| | - Zeynep S Agim
- School of Health Sciences, Purdue University, West Lafayette, Indiana 47907
| | - Vartika R Mishra
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana 47907
| | - Mitali A Tambe
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana 47907
| | - Alison E Director-Myska
- Chemical/Biological Technologies, Defense Threat Reduction Agency, Fort Belvoir, Virginia 22060
| | - Kenneth W Turteltaub
- Biosciences & Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, California 94551
| | - George P McCabe
- Department of Statistics, Purdue University, West Lafayette, Indiana 47907
| | - Jean-Christophe Rochet
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana 47907
| | - Jason R Cannon
- School of Health Sciences, Purdue University, West Lafayette, Indiana 47907
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17
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Iodine-129 microdosing for protein and peptide drug development: erythropoietin as a case study. Bioanalysis 2013; 5:53-63. [PMID: 23256472 DOI: 10.4155/bio.12.297] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND Microdosing is a technique for studying the behavior of compounds in vivo at 1/100th of the dose of a test substance calculated, based on animal data, to yield a pharmacologic effect. In microdosing, use is made of accelerator MS (AMS). In this study, we investigated whether (129)I-labeling of proteins with subsequent AMS measurements is a suitable method to perform microdose studies with therapeutic proteins. We used erythropoietin (EPO) as a case study. RESULTS In an animal study with (129)I-labeled EPO in Han-Wistar rats, an increase of (129)I-EPO is observed after dose administration. The half-life was found to be 2 and 5.5 h for two different EPOs. These results are in accordance with expected values. CONCLUSION Although further research is required, (129)I-labeling of proteins seems a feasible method for AMS microdose studies with peptide and protein drugs, such as biosimilars.
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18
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Gilsing AMJ, Fransen F, de Kok TM, Goldbohm AR, Schouten LJ, de Bruïne AP, van Engeland M, van den Brandt PA, de Goeij AFPM, Weijenberg MP. Dietary heme iron and the risk of colorectal cancer with specific mutations in KRAS and APC. Carcinogenesis 2013; 34:2757-66. [PMID: 23983135 DOI: 10.1093/carcin/bgt290] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Red meat intake has been linked to increased colorectal cancer (CRC) risk. Although the underlying mechanisms remain unclear, experimental studies suggest a role for dietary heme iron. Because heme iron was shown to promote specific mutations, it would be insightful to link heme iron data to CRC with mutations in key genes in an observational, population-based study. We investigated the association between dietary heme iron intake and risk of CRC with mutations in APC (adenomatous polyposis coli) and KRAS (Kirsten ras) and P53 overexpression in the Netherlands Cohort Study. After 7.3 years of follow-up, excluding the first 2.3 years due to incomplete coverage of the pathology registry and to avoid preclinical disease, adjusted hazard ratios (including adjustment for total meat) and 95% confidence intervals were calculated, using 4026 subcohort members (aged 55-69 years at baseline), 435 colon and 140 rectal cancer patients. When comparing the highest with the lowest tertile of intake, heme iron intake was associated with an increased risk of CRC harboring activating mutations in KRAS (hazard ratio = 1.71, 95% confidence interval: 1.15-2.57; P for trend = 0.03) and CRC without truncating mutations in APC (hazard ratio = 1.79, 95% confidence interval: 1.23-2.60; P for trend = 0.003). We observed a positive association between heme iron intake and the risk of CRC with activating G>A mutations in KRAS (P for trend = 0.01) and overall G>A mutations in APC (P for trend = 0.005). No associations were found with CRC harboring G>T mutations in KRAS/APC. Heme iron intake was positively associated with the risk of P53 overexpressed tumors but not with tumors without P53 overexpression (Pheterogeneity = 0.12). Heme iron intake was associated with an increased risk of colorectal tumors harboring G>A transitions in KRAS and APC and overexpression of P53. These novel findings suggest that alkylating rather than oxidative DNA-damaging mechanisms are involved in heme-induced colorectal carcinogenesis.
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Chung IM, Kim SH. Biological and biomedical (14)C-accelerator mass spectrometry and graphitization of carbonaceous samples. Analyst 2013; 138:3347-55. [PMID: 23626987 DOI: 10.1039/c3an00077j] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Accelerator mass spectrometry (AMS) is the ultimate technique for measuring rare isotopes in small samples. Biological and biomedical applications of (14)C-AMS (bio-(14)C-AMS) commenced in the early 1990s and are now widely used in many research fields including pharmacology, toxicology, food, and nutrition. For accurate, precise, and reproducible bio-(14)C-AMS analysis, the graphitization step in sample preparation is the most critical step. So, various sample preparation methods for a process called graphitization have been reported for specific applications. Catalytic graphitization using either a flame-sealed borosilicate tube or a septa-sealed vial is a popular sample preparation method for bio-(14)C-AMS. In this review, we introduce the AMS system, especially for bio-(14)C-AMS. In addition, we also review the graphitization method for bio-(14)C-AMS to promote further understanding and improvement of sample preparation for this technique. Examples of catalytic graphitization methods over the past two decades are described.
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Affiliation(s)
- Ill-Min Chung
- Department of Applied Bioscience, College of Life and Environmental Science, Konkuk University, Seoul 143-701, Republic of Korea
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20
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Lappin G, Noveck R, Burt T. Microdosing and drug development: past, present and future. Expert Opin Drug Metab Toxicol 2013; 9:817-34. [PMID: 23550938 DOI: 10.1517/17425255.2013.786042] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
INTRODUCTION Microdosing is an approach to early drug development where exploratory pharmacokinetic data are acquired in humans using inherently safe sub-pharmacologic doses of drug. The first publication of microdose data was 10 years ago and this review comprehensively explores the microdose concept from conception, over the past decade, up until the current date. AREAS COVERED The authors define and distinguish the concept of microdosing from similar approaches. The authors review the ability of microdosing to provide exploratory pharmacokinetics (concentration-time data) but exclude microdosing using positron emission tomography. The article provides a comprehensive review of data within the peer-reviewed literature as well as the latest applications and a look into the future, towards where microdosing may be headed. EXPERT OPINION Evidence so far suggests that microdosing may be a better predictive tool of human pharmacokinetics than alternative methods and combination with physiologically based modelling may lead to much more reliable predictions in the future. The concept has also been applied to drug-drug interactions, polymorphism and assessing drug concentrations over time at its site of action. Microdosing may yet have more to offer in unanticipated directions and provide benefits that have not been fully realised to date.
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Affiliation(s)
- Graham Lappin
- University of Lincoln, Brayford Pool, Lincoln, LN6 7TS, UK.
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21
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Jamin EL, Riu A, Douki T, Debrauwer L, Cravedi JP, Zalko D, Audebert M. Combined genotoxic effects of a polycyclic aromatic hydrocarbon (B(a)P) and an heterocyclic amine (PhIP) in relation to colorectal carcinogenesis. PLoS One 2013; 8:e58591. [PMID: 23484039 PMCID: PMC3590161 DOI: 10.1371/journal.pone.0058591] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Accepted: 02/05/2013] [Indexed: 12/21/2022] Open
Abstract
Colorectal neoplasia is the third most common cancer worldwide. Environmental factors such as diet are known to be involved in the etiology of this cancer. Several epidemiological studies have suggested that specific neo-formed mutagenic compounds related to meat consumption are an underlying factor involved in the association between diet and colorectal cancer. Heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs) are known mutagens and possible human carcinogens formed at the same time in meat during cooking processes. We studied the genotoxicity of the model PAH benzo(a)pyrene (B(a)P) and HCA 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), alone or in mixture, using the mouse intestinal cell line ApcMin/+, mimicking the early step of colorectal carcinogenesis, and control Apc+/+ cells. The genotoxicity of B(a)P and PhIP was investigated using both cell lines, through the quantification of B(a)P and PhIP derived DNA adducts, as well as the use of a genotoxic assay based on histone H2AX phosphorylation quantification. Our results demonstrate that heterozygous Apc mutated cells are more effective to metabolize B(a)P. We also established in different experiments that PhIP and B(a)P were more genotoxic on ApcMin/+ cells compared to Apc+/+. Moreover when tested in mixture, we observed a combined genotoxicity of B(a)P and PhIP on the two cell lines, with an increase of PhIP derived DNA adducts in the presence of B(a)P. Because of their genotoxic effects observed on heterozygous Apc mutated cells and their possible combined genotoxic effects, both B(a)P and PhIP, taken together, could be implicated in the observed association between meat consumption and colorectal cancer.
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Affiliation(s)
- Emilien L. Jamin
- INRA, UMR1331, Toxalim, Research Centre in Food Toxicology, Toulouse, France
- Université de Toulouse, INPT, UPS, UMR1331, Toulouse, France
| | - Anne Riu
- INRA, UMR1331, Toxalim, Research Centre in Food Toxicology, Toulouse, France
- Université de Toulouse, INPT, UPS, UMR1331, Toulouse, France
| | - Thierry Douki
- Laboratoire « Lésions des Acides Nucléiques », Université Joseph Fourier – Grenoble 1/CEA/Institut Nanoscience et Cryogénie/SCIB, UMR-E3, Grenoble, France
| | - Laurent Debrauwer
- INRA, UMR1331, Toxalim, Research Centre in Food Toxicology, Toulouse, France
- Université de Toulouse, INPT, UPS, UMR1331, Toulouse, France
| | - Jean-Pierre Cravedi
- INRA, UMR1331, Toxalim, Research Centre in Food Toxicology, Toulouse, France
- Université de Toulouse, INPT, UPS, UMR1331, Toulouse, France
| | - Daniel Zalko
- INRA, UMR1331, Toxalim, Research Centre in Food Toxicology, Toulouse, France
- Université de Toulouse, INPT, UPS, UMR1331, Toulouse, France
| | - Marc Audebert
- INRA, UMR1331, Toxalim, Research Centre in Food Toxicology, Toulouse, France
- Université de Toulouse, INPT, UPS, UMR1331, Toulouse, France
- * E-mail:
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Miller PE, Lazarus P, Lesko SM, Cross AJ, Sinha R, Laio J, Zhu J, Harper G, Muscat JE, Hartman TJ. Meat-related compounds and colorectal cancer risk by anatomical subsite. Nutr Cancer 2013; 65:202-26. [PMID: 23441608 PMCID: PMC3584417 DOI: 10.1080/01635581.2013.756534] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Since meat may be involved in the etiology of colorectal cancer, associations between meat-related compounds were examined to elucidate underlying mechanisms in a population-based case-control study. Participants (989 cases/1,033 healthy controls) completed a food frequency questionnaire with a meat-specific module. Multivariable logistic regression was used to examine associations between meat variables and colorectal cancer; polytomous logistic regression was used for subsite-specific analyses. The following significant positive associations were observed for meat-related compounds: 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (DiMeIQx) and colorectal, distal colon, and rectal tumors; 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) and colorectal and colon cancer tumors; nitrites/nitrates and proximal colon cancer; 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and rectal cancer; and benzo[a]pyrene and rectal cancer (P-trends < 0.05). For analyses by meat type, cooking method, and doneness preference, positive associations between red processed meat and proximal colon cancer and pan-fried red meat and colorectal cancer were found (P-trends < 0.05). Inverse associations were observed between unprocessed poultry and colorectal, colon, proximal colon, and rectal tumors; grilled/barbequed poultry and proximal colon cancer; and well-done/charred poultry and colorectal, colon, and proximal colon tumors (P-trends < 0.05). HCAs, PAHs, nitrites, and nitrates may be involved in colorectal cancer etiology. Further examination into the unexpected inverse associations between poultry and colorectal cancer is warranted.
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Affiliation(s)
- Paige E Miller
- Cancer Prevention Fellowship Program, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA.
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Deziel NC, Buckley TJ, Sinha R, Abubaker S, Platz EA, Strickland PT. Comparability and repeatability of methods for estimating the dietary intake of the heterocyclic amine contaminant 2-amino-1-methyl-6-phenylimidazo[4,5b]pyridine (PhIP). Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2012; 29:1202-11. [PMID: 22571725 PMCID: PMC3412362 DOI: 10.1080/19440049.2012.682657] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Inconsistent risk estimates for dietary heterocyclic amine (HCA) exposure and cancers may be due to differences in exposure assessment methods and the associated measurement error. We evaluated repeatability and comparability of intake estimates of the HCA 2-amino-1-methyl-6-phenylimidazo[4,5b]pyridine (PhIP) among two food frequency questionnaire (FFQ) collections, three diary collections, and three measurements of urinary PhIP and its metabolites in 36 non-smokers in Baltimore, Maryland, during 2004-2005. Collections spanned ∼9 months. Method repeatability was characterised with intraclass correlation coefficients (ICCs). Comparability among methods was assessed with Spearman correlation coefficients. Within-subject variability in PhIP intake was comparably high across all methods (ICCs of 0.20, 0.30, and 0.15 for FFQ, diary, and creatinine-adjusted urinary PhIP, respectively). Mean diary-based PhIP intake and mean urinary PhIP concentration were strongly correlated when restricting the analysis to participants with at least one non-zero diary-based estimate of PhIP intake (n = 15, r = 0.75, p = 0.001), but not in the full study population (n = 36, r = 0.18, p = 0.28). Mean PhIP intake from the FFQ was not associated with that either based on the diary or urinary PhIP separately, but was modestly correlated with a metric that combined the diary- and biomarker-based approaches (r = 0.30, p = 0.08). The high within-subject variability will result in significantly attenuated associations if a single measure is used to estimate exposure within an epidemiologic study. Improved HCA assessment tools, such as a combination of methods or validated biomarkers that capture long term exposure, are needed.
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Affiliation(s)
- Nicole C Deziel
- Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe St., Baltimore, MD, USA.
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24
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Svendsen C, Meinl W, Glatt H, Alexander J, Knutsen HK, Hjertholm H, Rasmussen T, Husøy T. Intestinal carcinogenesis of two food processing contaminants, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine and 5-hydroxymethylfurfural, in transgenic FVB min mice expressing human sulfotransferases. Mol Carcinog 2011; 51:984-92. [PMID: 22006426 DOI: 10.1002/mc.20869] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Revised: 09/13/2011] [Accepted: 09/14/2011] [Indexed: 02/05/2023]
Abstract
Humans express sulfotransferases (SULTs) of the SULT1A subfamily in many tissues, whilst the single SULT1A gene present in rodents is mainly expressed in liver. The food processing contaminants, 5-hydroxymethylfurfural (HMF) and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), are bioactivated by human SULT1A1 and SULT1A2. FVB multiple intestinal neoplasia (Min) mice, which spontaneously develop tumors and flat aberrant crypt foci (ACF) in intestine, were crossed with transgenic FVB mice expressing human SULT1A1 and 1A2 (hSULT) in several tissues, giving rise to wild-type and Min mice with and without hSULT. One-week-old Min mice with or without hSULT were given HMF (375 or 750 mg/kg bw) or saline by gavage three times a week for 11 wk. In another experiment, the F1 generation received subcutaneous injections of 50 mg/kg bw PhIP or saline 1 wk before birth, and 1, 2, and 3 wk after birth. HMF did not affect the formation of tumors, but may have induced some flat ACF (incidence 15-20%) in Min mice with and without hSULT. No control mouse developed any flat ACF. With the limitation that these putative effects were weak, they were unaffected by hSULT expression. The carcinogenic effect of PhIP increased in the presence of hSULT, with a significant increase in both incidence (31-80%) and number of colonic tumors (0.4-1.3 per animal). Thus, intestinal expression of human SULT1A1 and 1A2 might increase the susceptibility to compounds bioactivated via this pathway implying that humans might be more susceptible than conventional rodent models.
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Affiliation(s)
- Camilla Svendsen
- Norwegian Institute of Public Health, Division of Environmental Medicine, Department of Food Safety and Nutrition, Nydalen, Oslo, Norway
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25
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Turesky RJ, Le Marchand L. Metabolism and biomarkers of heterocyclic aromatic amines in molecular epidemiology studies: lessons learned from aromatic amines. Chem Res Toxicol 2011; 24:1169-214. [PMID: 21688801 PMCID: PMC3156293 DOI: 10.1021/tx200135s] [Citation(s) in RCA: 217] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Aromatic amines and heterocyclic aromatic amines (HAAs) are structurally related classes of carcinogens that are formed during the combustion of tobacco or during the high-temperature cooking of meats. Both classes of procarcinogens undergo metabolic activation by N-hydroxylation of the exocyclic amine group to produce a common proposed intermediate, the arylnitrenium ion, which is the critical metabolite implicated in toxicity and DNA damage. However, the biochemistry and chemical properties of these compounds are distinct, and different biomarkers of aromatic amines and HAAs have been developed for human biomonitoring studies. Hemoglobin adducts have been extensively used as biomarkers to monitor occupational and environmental exposures to a number of aromatic amines; however, HAAs do not form hemoglobin adducts at appreciable levels, and other biomarkers have been sought. A number of epidemiologic studies that have investigated dietary consumption of well-done meat in relation to various tumor sites reported a positive association between cancer risk and well-done meat consumption, although some studies have shown no associations between well-done meat and cancer risk. A major limiting factor in most epidemiological studies is the uncertainty in quantitative estimates of chronic exposure to HAAs, and thus, the association of HAAs formed in cooked meat and cancer risk has been difficult to establish. There is a critical need to establish long-term biomarkers of HAAs that can be implemented in molecular epidemioIogy studies. In this review, we highlight and contrast the biochemistry of several prototypical carcinogenic aromatic amines and HAAs to which humans are chronically exposed. The biochemical properties and the impact of polymorphisms of the major xenobiotic-metabolizing enzymes on the biological effects of these chemicals are examined. Lastly, the analytical approaches that have been successfully employed to biomonitor aromatic amines and HAAs, and emerging biomarkers of HAAs that may be implemented in molecular epidemiology studies are discussed.
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Affiliation(s)
- Robert J Turesky
- Division of Environmental Health Sciences, Wadsworth Center , Albany, New York 12201, United States.
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26
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Gao L, Li J, Kasserra C, Song Q, Arjomand A, Hesk D, Chowdhury SK. Precision and Accuracy in the Quantitative Analysis of Biological Samples by Accelerator Mass Spectrometry: Application in Microdose Absolute Bioavailability Studies. Anal Chem 2011; 83:5607-16. [DOI: 10.1021/ac2006284] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | | | | | - Qi Song
- Accium BioSciences, Inc., Seattle, Washington 98122, United States
| | - Ali Arjomand
- Accium BioSciences, Inc., Seattle, Washington 98122, United States
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Dueker SR, Vuong LT, Lohstroh PN, Giacomo JA, Vogel JS. Quantifying exploratory low dose compounds in humans with AMS. Adv Drug Deliv Rev 2011; 63:518-31. [PMID: 21047543 PMCID: PMC3062634 DOI: 10.1016/j.addr.2010.10.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2010] [Revised: 10/08/2010] [Accepted: 10/18/2010] [Indexed: 11/20/2022]
Abstract
Accelerator Mass Spectrometry is an established technology whose essentiality extends beyond simply a better detector for radiolabeled molecules. Attomole sensitivity reduces radioisotope exposures in clinical subjects to the point that no population need be excluded from clinical study. Insights in human physiochemistry are enabled by the quantitative recovery of simplified AMS processes that provide biological concentrations of all labeled metabolites and total compound related material at non-saturating levels. In this paper, we review some of the exploratory applications of AMS (14)C in toxicological, nutritional, and pharmacological research. This body of research addresses the human physiochemistry of important compounds in their own right, but also serves as examples of the analytical methods and clinical practices that are available for studying low dose physiochemistry of candidate therapeutic compounds, helping to broaden the knowledge base of AMS application in pharmaceutical research.
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Accelerator mass spectrometry-enabled studies: current status and future prospects. Bioanalysis 2011; 2:519-41. [PMID: 20440378 DOI: 10.4155/bio.09.188] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Accelerator mass spectrometry is a detection platform with exceptional sensitivity compared with other bioanalytical platforms. Accelerator mass spectrometry (AMS) is widely used in archeology for radiocarbon dating applications. Early exploration of the biological and pharmaceutical applications of AMS began in the early 1990s. AMS has since demonstrated unique problem-solving ability in nutrition science, toxicology and pharmacology. AMS has also enabled the development of new applications, such as Phase 0 microdosing. Recent development of AMS-enabled applications has transformed this novelty research instrument to a valuable tool within the pharmaceutical industry. Although there is now greater awareness of AMS technology, recognition and appreciation of the range of AMS-enabled applications is still lacking, including study-design strategies. This review aims to provide further insight into the wide range of AMS-enabled applications. Examples of studies conducted over the past two decades will be presented, as well as prospects for the future of AMS.
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29
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Cheung C, Loy S, Li GX, Liu AB, Yang CS. Rapid induction of colon carcinogenesis in CYP1A-humanized mice by 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine and dextran sodium sulfate. Carcinogenesis 2010; 32:233-9. [PMID: 21081470 DOI: 10.1093/carcin/bgq235] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), the most abundant heterocyclic amine produced during the cooking of meats and fish, is suspected to be a human carcinogen. Metabolic activation of PhIP is primarily mediated by the enzyme cytochrome P450 (CYP) 1A2. Metabolism of PhIP by CYP1A2 differs considerably between humans and rodents, with more N(2)-hydroxylation (activation) and less 4'-hydroxylation (detoxication) in humans. Transgenic CYP1A-humanized mice (hCYP1A-mice), which have the human CYP1A1 and CYP1A2 genes but lack the murine orthologs Cyp1a1 and Cyp1a2, provide an excellent opportunity to develop a relevant model to study dietary-induced colon carcinogenesis. The treatment with 200 mg/kg PhIP by oral gavage, followed by 1.5% dextran sodium sulfate (DSS) in the drinking water for 7 days, was found to be an effective combination to induce colon carcinogenesis in hCYP1A-mice. Tumor multiplicity at week 6 was calculated to be 3.75 ± 0.70 and for week 10 was 3.90 ± 0.61 with 80-95% of the tumors being adenocarcinomas. No tumors were found in the similarly treated wild-type mice. Western blots revealed overexpression of β-catenin, c-Myc, cyclin D1, inducible nitric oxide synthase and cyclooxygenase-2 in colon tumor samples. Strong nuclear localization of β-catenin was observed in tumors. These results illustrate that PhIP and DSS combination produces rapid colon carcinogenesis in hCYP1A-mice and this is an effective model to mimic human colon carcinogenesis.
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Affiliation(s)
- Connie Cheung
- Department of Chemical Biology, Susan Lehman Cullman Laboratory for Cancer Research, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, NJ 08854-8020, USA
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Abstract
OBJECTIVE To characterize the trends, distribution, potential determinants and public health implications of meat consumption within the USA. DESIGN We examined temporal trends in meat consumption using food availability data from the FAO and US Department of Agriculture (USDA), and further evaluated the meat intake by type (red, white, processed) in the National Health and Nutrition Examination Surveys (NHANES) linked to the MyPyramid Equivalents Database (MPED). RESULTS Overall meat consumption has continued to rise in the USA and the rest of the developed world. Despite a shift towards higher poultry consumption, red meat still represents the largest proportion of meat consumed in the USA (58 %). Twenty-two per cent of the meat consumed in the USA is processed. According to the NHANES 2003-2004, total meat intake averaged 128 g/d. The type and quantities of meat reported varied by education, race, age and gender. CONCLUSIONS Given the plausible epidemiological evidence for red and processed meat intake in cancer and chronic disease risk, understanding the trends and determinants of meat consumption in the USA, where meat is consumed at more than three times the global average, should be particularly pertinent to researchers and other public health professionals aiming to reduce the global burden of chronic disease.
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31
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Henderson PT, Evans MD, Cooke MS. Salvage of oxidized guanine derivatives in the (2'-deoxy)ribonucleotide pool as source of mutations in DNA. Mutat Res 2010; 703:11-7. [PMID: 20833264 DOI: 10.1016/j.mrgentox.2010.08.021] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2010] [Accepted: 08/31/2010] [Indexed: 01/08/2023]
Abstract
Recent evidence suggests that salvage of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) and 8-oxo-7,8-dihydro-guanine (8-oxoGua) can contribute substantially to levels of 8-oxoGua in DNA and RNA. However, it remains to be determined if this mechanism contributes to mutagenesis and disease. This review covers the predominant methods for detecting 8-oxoGua and its derivatives, summarizes some of the relevant recent DNA repair studies and discusses the mechanisms for metabolism of oxidized guanine derivatives in the (2'-deoxy)ribonucleoside and (2'-deoxy)ribonucleotide pools.
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Affiliation(s)
- Paul T Henderson
- Division of Hematology and Oncology, Department of Internal Medicine, University of California Davis Medical Center, 4501 X Street, Suite 3016, Sacramento, CA 95817, USA.
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32
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Singh R, Arlt VM, Henderson CJ, Phillips DH, Farmer PB, Gamboa da Costa G. Detection and quantitation of N-(deoxyguanosin-8-yl)-2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine adducts in DNA using online column-switching liquid chromatography tandem mass spectrometry. J Chromatogr B Analyt Technol Biomed Life Sci 2010; 878:2155-62. [PMID: 20598652 PMCID: PMC2923026 DOI: 10.1016/j.jchromb.2010.06.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2010] [Revised: 06/03/2010] [Accepted: 06/03/2010] [Indexed: 10/19/2022]
Abstract
The heterocyclic aromatic amine, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is formed by the grilled cooking of certain foods such as meats, poultry and fish. PhIP has been shown to induce tumours in the colon, prostate and mammary glands of rats and is regarded as a potential human dietary carcinogen. PhIP is metabolically activated via cytochrome P450 mediated oxidation to an N-hydroxylamino-PhIP intermediate that is subsequently converted to an ester by N-acetyltransferases or sulfotransferases and undergoes heterolytic cleavage to produce a PhIP-nitrenium ion, which reacts with DNA to form the N-(deoxyguanosin-8-yl)-2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP-C8-dG) adduct. Thus far, the detection and quantification of PhIP-DNA adducts has relied to a large extent on (32)P-postlabelling methodologies. In order to expand the array of available techniques for the detection and improved quantification of PhIP-C8-dG adducts in DNA we have developed an online column-switching liquid chromatography (LC)-electrospray ionization (ESI)-tandem mass spectrometry (MS/MS) selected reaction monitoring (SRM) method incorporating an isotopically [(13)C(10)]-labelled PhIP-C8-dG internal standard for the analysis of DNA enzymatically hydrolysed to 2'-deoxynucleosides. A dose-dependent increase was observed for PhIP-C8-dG adducts when salmon testis DNA was reacted with N-acetoxy-PhIP. Analysis of DNA samples isolated from colon tissue of mice treated by oral gavage daily for 5 days with 50 mg/kg body weight of PhIP resulted in the detection of an average level of 14.8+/-3.7 PhIP-C8-dG adducts per 10(6) 2'-deoxynucleosides. The method required 50 microg of hydrolysed animal DNA on column and the limit of detection for PhIP-C8-dG was 2.5 fmol (1.5 PhIP-C8-dG adducts per 10(8) 2'-deoxynucleosides). In summary, the LC-ESI-MS/MS SRM method provides for the rapid automation of the sample clean up and a reduction in matrix components that would otherwise interfere with the mass spectrometric analysis, with sufficient sensitivity and precision to analyse DNA adducts in animals exposed to PhIP.
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Affiliation(s)
- Rajinder Singh
- Cancer Biomarkers and Prevention Group, Biocentre, Department of Cancer Studies and Molecular Medicine, University of Leicester, University Road, Leicester LE1 7RH, UK.
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Kim SH, Kelly PB, Clifford AJ. Calculating radiation exposures during use of (14)C-labeled nutrients, food components, and biopharmaceuticals to quantify metabolic behavior in humans. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2010; 58:4632-7. [PMID: 20349979 PMCID: PMC2857889 DOI: 10.1021/jf100113c] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2010] [Revised: 03/12/2010] [Accepted: 03/16/2010] [Indexed: 05/29/2023]
Abstract
(14)C has long been used as a tracer for quantifying the in vivo human metabolism of food components, biopharmaceuticals, and nutrients. Minute amounts (< or =1 x 10 (-18) mol) of (14)C can be measured with high-throughput (14)C-accelerator mass spectrometry (HT (14)C-AMS) in isolated chemical extracts of biological, biomedical, and environmental samples. Availability of in vivo human data sets using a (14)C tracer would enable current concepts of the metabolic behavior of food components, biopharmaceuticals, or nutrients to be organized into models suitable for quantitative hypothesis testing and determination of metabolic parameters. In vivo models are important for specification of intake levels for food components, biopharmaceuticals, and nutrients. Accurate estimation of the radiation exposure from ingested (14)C is an essential component of the experimental design. Therefore, this paper illustrates the calculation involved in determining the radiation exposure from a minute dose of orally administered (14)C-beta-carotene, (14)C-alpha-tocopherol, (14)C-lutein, and (14)C-folic acid from four prior experiments. The administered doses ranged from 36 to 100 nCi, and radiation exposure ranged from 0.12 to 5.2 microSv to whole body and from 0.2 to 3.4 microSv to liver with consideration of tissue weighting factor and fractional nutrient. In comparison, radiation exposure experienced during a 4 h airline flight across the United States at 37000 ft was 20 microSv.
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Links J, Palmblad M, Ognibene T, Turteltaub K, Bench G. Quantitative metabolism using AMS: Choosing a labeled precursor. NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH. SECTION B, BEAM INTERACTIONS WITH MATERIALS AND ATOMS 2010; 268:1309-1312. [PMID: 20368758 PMCID: PMC2847305 DOI: 10.1016/j.nimb.2009.10.160] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Biological radioisotope studies suffer from a lack of sensitive measurement techniques and therefore traditionally require large amounts of labeled material to produce a measurable signal. Such quantities of materials are often significantly higher than naturally-occurring levels preventing these studies from replicating physiological conditions. AMS affords the sensitivity necessary to perform biological radioisotope studies with low levels of labeled material that preserve physiological conditions. The choice of labeled material can substantially affect the ease of interpretation and comprehensiveness of these studies. Here, the benefits and limitations of whole-cell labeling with (14)C-glucose and targeted pathway labeling with (14)C-nicotinic acid are discussed and compared.
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Affiliation(s)
- Jennifer Links
- Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, Livermore, CA 94551, United States
| | - Magnus Palmblad
- Department of Parasitology, Leiden University, Leiden, Netherlands
| | - Ted Ognibene
- Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, Livermore, CA 94551, United States
| | - Ken Turteltaub
- Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, Livermore, CA 94551, United States
| | - Graham Bench
- Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, Livermore, CA 94551, United States
- Corresponding author. Address: Center For Accelerator Mass Spectrometry L-397, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94551
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Ma X, Park Y, Mayne ST, Wang R, Sinha R, Hollenbeck AR, Schatzkin A, Cross AJ. Diet, lifestyle, and acute myeloid leukemia in the NIH-AARP cohort. Am J Epidemiol 2010; 171:312-22. [PMID: 20042434 DOI: 10.1093/aje/kwp371] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The relation between diet, lifestyle, and acute myeloid leukemia was assessed in a US cohort of 491,163 persons from the NIH-AARP Diet and Health Study (1995-2003). A total of 338 incident cases of acute myeloid leukemia were ascertained. Multivariate Cox models were utilized to estimate hazard ratios and 95% confidence intervals. Compared with those for never smokers, hazard ratios were 1.29 (95% confidence interval: 0.95, 1.75), 1.79 (95% confidence interval: 1.32, 2.42), 2.42 (95% confidence interval: 1.63, 3.57), and 2.29 (85% confidence interval: 1.38, 3.79) for former smokers who smoked < or =1 or >1 pack/day and for current smokers who smoked < or =1 or >1 pack/day, respectively. Higher meat intake was associated with an increased risk of acute myeloid leukemia (hazard ratio = 1.45, 95% confidence interval: 1.02, 2.07 for the fifth vs. first quintile; P for trend = 0.06); however, there were no clear effects of meat-cooking method or doneness level. Individuals who did not drink coffee appeared to have a higher risk of acute myeloid leukemia than those who drank various quantities of coffee. Neither fruit nor vegetable intake was associated with acute myeloid leukemia. This large prospective study identified smoking and meat intake as risk factors for acute myeloid leukemia.
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Affiliation(s)
- Xiaomei Ma
- Division of Chronic Disease Epidemiology, Yale University School of Public Health, New Haven, Connecticut, USA.
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36
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Rubino FM, Pitton M, Di Fabio D, Colombi A. Toward an "omic" physiopathology of reactive chemicals: thirty years of mass spectrometric study of the protein adducts with endogenous and xenobiotic compounds. MASS SPECTROMETRY REVIEWS 2009; 28:725-84. [PMID: 19127566 DOI: 10.1002/mas.20207] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Cancer and degenerative diseases are major causes of morbidity and death, derived from the permanent modification of key biopolymers such as DNA and regulatory proteins by usually smaller, reactive molecules, present in the environment or generated from endogenous and xenobiotic components by the body's own biochemical mechanisms (molecular adducts). In particular, protein adducts with organic electrophiles have been studied for more than 30 [see, e.g., Calleman et al., 1978] years essentially for three purposes: (a) as passive monitors of the mean level of individual exposure to specific chemicals, either endogenously present in the human body or to which the subject is exposed through food or environmental contamination; (b) as quantitative indicators of the mean extent of the individual metabolic processing which converts a non-reactive chemical substance into its toxic products able to damage DNA (en route to cancer induction through genotoxic mechanisms) or key proteins (as in the case of several drugs, pesticides or otherwise biologically active substances); (c) to relate the extent of protein modification to that of biological function impairment (such as enzyme inhibition) finally causing the specific health damage. This review describes the role that contemporary mass spectrometry-based approaches employed in the qualitative and quantitative study of protein-electrophile adducts play in the discovery of the (bio)chemical mechanisms of toxic substances and highlights the future directions of research in this field. A particular emphasis is given to the measurement of often high levels of the protein adducts of several industrial and environmental pollutants in unexposed human populations, a phenomenon which highlights the possibility that a number of small organic molecules are generated in the human organism through minor metabolic processes, the imbalance of which may be the cause of "spontaneous" cases of cancer and of other degenerative diseases of still uncharacterized etiology. With all this in mind, it is foreseen that a holistic description of cellular functions will take advantage of new analytical methods based on time-integrated metabolomic measurements of a new biological compartment, the "adductome," aimed at better understanding integrated organism response to environmental and endogenous stressors.
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Affiliation(s)
- Federico Maria Rubino
- Laboratory for Analytical Toxicology and Metabonomics, Department of Medicine, Surgery and Odontology, Università degli Studi di Milano at Ospedale San Paolo, v. Antonio di Rudinì 8, Milano I-20142, Italy.
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Hah SS, Henderson PT, Turteltaub KW. Recent advances in biomedical applications of accelerator mass spectrometry. J Biomed Sci 2009; 16:54. [PMID: 19534792 PMCID: PMC2712465 DOI: 10.1186/1423-0127-16-54] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2008] [Accepted: 06/17/2009] [Indexed: 11/13/2022] Open
Abstract
The use of radioisotopes has a long history in biomedical science, and the technique of accelerator mass spectrometry (AMS), an extremely sensitive nuclear physics technique for detection of very low-abundant, stable and long-lived isotopes, has now revolutionized high-sensitivity isotope detection in biomedical research, because it allows the direct determination of the amount of isotope in a sample rather than measuring its decay, and thus the quantitative analysis of the fate of the radiolabeled probes under the given conditions. Since AMS was first used in the early 90's for the analysis of biological samples containing enriched 14C for toxicology and cancer research, the biomedical applications of AMS to date range from in vitro to in vivo studies, including the studies of 1) toxicant and drug metabolism, 2) neuroscience, 3) pharmacokinetics, and 4) nutrition and metabolism of endogenous molecules such as vitamins. In addition, a new drug development concept that relies on the ultrasensitivity of AMS, known as human microdosing, is being used to obtain early human metabolism information of candidate drugs. These various aspects of AMS are reviewed and a perspective on future applications of AMS to biomedical research is provided.
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Affiliation(s)
- Sang Soo Hah
- Department of Chemistry and Research Institute for Basic Sciences, Kyung Hee University 1 Hoegi-dong, Dongdaemun-gu, Seoul 130-701, Korea.
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Cheung C, Gonzalez FJ. Humanized mouse lines and their application for prediction of human drug metabolism and toxicological risk assessment. J Pharmacol Exp Ther 2008; 327:288-99. [PMID: 18682571 DOI: 10.1124/jpet.108.141242] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Cytochrome P450s (P450s) are important enzymes involved in the metabolism of xenobiotics, particularly clinically used drugs, and are also responsible for metabolic activation of chemical carcinogens and toxins. Many xenobiotics can activate nuclear receptors that in turn induce the expression of genes encoding xenobiotic metabolizing enzymes and drug transporters. Marked species differences in the expression and regulation of cytochromes P450 and xenobiotic nuclear receptors exist. Thus, obtaining reliable rodent models to accurately reflect human drug and carcinogen metabolism is severely limited. Humanized transgenic mice were developed in an effort to create more reliable in vivo systems to study and predict human responses to xenobiotics. Human P450s or human xenobiotic-activated nuclear receptors were introduced directly or replaced the corresponding mouse gene, thus creating "humanized" transgenic mice. Mice expressing human CYP1A1/CYP1A2, CYP2E1, CYP2D6, CYP3A4, CY3A7, pregnane X receptor, and peroxisome proliferator-activated receptor alpha were generated and characterized. These humanized mouse models offer a broad utility in the evaluation and prediction of toxicological risk that may aid in the development of safer drugs.
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Affiliation(s)
- Connie Cheung
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Building 37, Room 3106, 9000 Rockville Pike, Bethesda, MD 20892, USA
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Frandsen H. Biomonitoring of urinary metabolites of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) following human consumption of cooked chicken. Food Chem Toxicol 2008; 46:3200-5. [PMID: 18692111 DOI: 10.1016/j.fct.2008.07.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2008] [Revised: 05/27/2008] [Accepted: 07/14/2008] [Indexed: 12/16/2022]
Abstract
Human risk assessment of exposure to 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) through the diet may be improved by conducting biomonitoring studies comparing metabolism in humans and rodents. Eleven volunteers ingested a meal of cooked chicken containing 4 -OH-PhIP and PhIP in amounts of 0.6 and 0.8microg/kg, respectively and urine was collected for the next 16h. The large number of PhIP metabolites was by treatment of the urine samples with hydrazine hydrate and hydrolytic enzymes reduced to three substances, 4'-OH-PhIP, PhIP and 5-OH-PhIP of which the first is a biomarker for detoxification and the last a biomarker for activation. The eleven volunteers eliminated large amounts of 4'-OH-PhIP in the urine. The majority of which could be accounted for by the presence of 4'-OH-PhIP in the fried chicken, showing that PhIP only to a small extent (11%) was metabolised to 4'-OH-PhIP. A larger fraction of the PhIP exposure, 38%, was recovered as PhIP and the largest fraction (51%) was recovered as 5-OH-PhIP suggesting that PhIP in humans to a large extent is metabolised to reactive substances. In rats, less than 1% of the dose of PhIP was eliminated as 5-OH-PhIP, suggesting that human cancer risk from exposure to PhIP is considerable higher than risk estimations based on extrapolation from rodent bioassays.
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Affiliation(s)
- H Frandsen
- National Food Institute, Technical University of Denmark, Mørkhøj Bygade 19, DK-2860 Søborg, Denmark.
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Plant N. Can systems toxicology identify common biomarkers of non-genotoxic carcinogenesis? Toxicology 2008; 254:164-9. [PMID: 18674585 DOI: 10.1016/j.tox.2008.07.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2008] [Revised: 06/30/2008] [Accepted: 07/01/2008] [Indexed: 10/25/2022]
Abstract
For the rapid development of safe, efficacious chemicals it is important that any potential liabilities are identified as early as possible in the discovery/development pipeline. Once identified it is then possible to make rational decisions on whether to progress a chemical and/or series further; one such liability is chemical carcinogenesis, a highly undesirable characteristic in a novel chemical entity. Chemical carcinogens may be roughly divided into two classes, those that elicit their actions through direct damage to DNA (genotoxic carcinogens) and those that cause carcinogenesis through mechanisms that involve direct damage of the DNA by the agent (non-genotoxic carcinogens). Whereas the former group can be identified by in vitro screens to a good degree of accuracy, the latter group are far more problematic due to their diverse modes of action. This review will focus on the latter class of chemical carcinogens, examining how modern '-omic' technologies have begun to identify signatures that may represent sensitive, early markers for these processes. In addition to their use in signature generation the role of -omic level approaches to delineating molecular mechanisms of action will also be discussed.
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Affiliation(s)
- Nick Plant
- Centre for Toxicology, Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey GU2 7XH, UK.
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41
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Follmann W, Birkner S. The use of cultured primary bovine colon epithelial cells as a screening model to detect genotoxic effects of heterocyclic aromatic amines in the comet assay. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2008; 71:947-953. [PMID: 18569600 DOI: 10.1080/15287390801988962] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Isolated epithelial cells from the bovine colon were maintained in dividing monolayer cultures and used as a model system for colon tissue in in vitro toxicological studies. The cytotoxic effects of the heterocyclic aromatic amines 2-amino-3-methylimidazo [4,5-f]quinoline (IQ) and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhiP) were investigated in these cells and IC(50) values were determined by inhibition of neutral red uptake into the cultured cells. Although PhiP was not cytotoxic up to concentrations of 500 microM, IQ was cytotoxic above 300 microM. The induction of DNA strand breaks in cultured bovine epithelial colon cells was determined using the alkaline single-cell gel electrophoresis (Comet assay) technique, and subsequently, the DNA damage was used as a determinant of genotoxic effects of the heterocyclic aromatic amines in order to establish this system for detection of adverse effects of chemicals in a model system for the colon. In the absence of an external enzymatic metabolizing system (S9 mix) both amines did not induce DNA strand breaks. When S9 mix was used, PhiP induced DNA strand breaks above 10 microM whereas IQ did not show any significant effect at 300 microM. This cell culture system was found to be a useful screening system for testing of compounds that are considered to affect colonic tissue.
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Affiliation(s)
- Wolfram Follmann
- Institut fur Arbeitsphysiologie an der Universitat Dortmund, Leibniz Research Centre for Working Environment and Human Factors, Dortmund, Germany
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42
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Cross AJ, Leitzmann MF, Gail MH, Hollenbeck AR, Schatzkin A, Sinha R. A prospective study of red and processed meat intake in relation to cancer risk. PLoS Med 2007; 4:e325. [PMID: 18076279 PMCID: PMC2121107 DOI: 10.1371/journal.pmed.0040325] [Citation(s) in RCA: 319] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2007] [Accepted: 10/01/2001] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Red meat and processed meat have been associated with carcinogenesis at several anatomic sites, but no prospective study has examined meat intake in relation to a range of malignancies. We investigated whether red or processed meat intake increases cancer risk at a variety of sites. METHODS AND FINDINGS The National Institutes of Health (NIH)-AARP (formerly the American Association for Retired Persons) Diet and Health Study is a cohort of approximately 500,000 people aged 50-71 y at baseline (1995-1996). Meat intake was estimated from a food frequency questionnaire administered at baseline. Cox proportional hazards regression was used to estimate hazard ratios and 95% confidence intervals within quintiles of red and processed meat intake. During up to 8.2 y of follow-up, 53,396 incident cancers were ascertained. Statistically significant elevated risks (ranging from 20% to 60%) were evident for esophageal, colorectal, liver, and lung cancer, comparing individuals in the highest with those in the lowest quintile of red meat intake. Furthermore, individuals in the highest quintile of processed meat intake had a 20% elevated risk for colorectal and a 16% elevated risk for lung cancer. CONCLUSIONS Both red and processed meat intakes were positively associated with cancers of the colorectum and lung; furthermore, red meat intake was associated with an elevated risk for cancers of the esophagus and liver.
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Affiliation(s)
- Amanda J Cross
- Nutritional Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Rockville, Maryland, United States of America.
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Murkovic M. Analysis of heterocyclic aromatic amines. Anal Bioanal Chem 2007; 389:139-46. [PMID: 17546447 DOI: 10.1007/s00216-007-1306-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2007] [Revised: 04/05/2007] [Accepted: 04/11/2007] [Indexed: 10/23/2022]
Abstract
Heterocyclic aromatic amines are formed in protein and amino acid-rich foods at temperatures above 150 degrees C. Of more than twenty heterocyclic aromatic amines identified ten have been shown to have carcinogenic potential. As nutritional hazards, their reliable determination in prepared food, their uptake and elimination in living organisms, including humans, and assessment of associated risks are important food-safety issues. The concentration in foods is normally in the low ng g(-1) range, which poses a challenge to the analytical chemist. Because of the complex nature of food matrixes, clean-up and enrichment of the extracts are also complex, usually involving both cation-exchange (propylsulfonic acid silica gel, PRS) and reversed-phase purification. The application of novel solid-phase extraction cartridges with a wettable apolar phase combined with cation-exchange characteristics simplified this process--both the polar and apolar heterocyclic aromatic amines were recovered in one fraction. Copper phthalocyanine trisulfonate bonded to cotton ("blue cotton") or rayon, and molecular imprinted polymers have also been successfully used for one-step sample clean-up. For analysis of the heterocyclic aromatic amines, liquid chromatography with base-deactivated reversed-phase columns has been used, and, recently, semi-micro and capillary columns have been introduced. The photometric, fluorimetric, or electrochemical detectors used previously have been replaced by mass spectrometers. Increased specificity and sub-ppb sensitivities have been achieved by the use of the selected-reaction-monitoring mode of detection of advanced MS instrumentation, for example the triple quadrupole and Q-TOF instrument combination. Gas chromatography, also with mass-selective detection, has been used for specific applications; the extra derivatization step needed for volatilization has been balanced by the higher chromatographic resolution.
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Affiliation(s)
- M Murkovic
- Institute for Food Chemistry and Technology, Graz University of Technology, Petersgasse 12/2, Graz, Austria.
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Deconjugation of N-glucuronide conjugated metabolites with hydrazine hydrate – Biomarkers for exposure to the food-borne carcinogen 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP). Food Chem Toxicol 2007; 45:863-70. [DOI: 10.1016/j.fct.2006.11.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2006] [Revised: 08/24/2006] [Accepted: 11/08/2006] [Indexed: 11/16/2022]
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45
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Busquets R, Puignou L, Galceran M. Determination of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) in hemoglobin using on-line coupling of restricted access material to liquid chromatography–mass spectrometry. Anal Chim Acta 2006. [DOI: 10.1016/j.aca.2005.11.052] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Lilla C, Risch A, Verla-Tebit E, Hoffmeister M, Brenner H, Chang-Claude J. SULT1A1 genotype and susceptibility to colorectal cancer. Int J Cancer 2006; 120:201-6. [PMID: 17013894 DOI: 10.1002/ijc.22156] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Several procarcinogens that are present in cooked red meat and tobacco smoke are substrates for sulfotransferase 1A1 (SULT1A1). The association between environmental exposures and colorectal cancer risk may be modified by individual differences in the metabolism. Thus, we investigated the effect of a common polymorphism in the SULT1A1 gene associated with decreased enzyme activity on the susceptibility to colorectal cancer in a population-based case-control study. Patients (505) and 604 age- and sex-matched controls provided detailed risk factor information and were genotyped for SULT1A1 G638A using a fluorescence-based melting curve analysis method. Multivariate logistic regression analysis was used to estimate colorectal cancer risk associated with environmental exposures by SULT1A1 genotype. SULT1A1 genotype was not an independent risk factor for colorectal cancer. Risk of colorectal cancer associated with frequent consumption of red meat was significantly elevated among carriers of the SULT1A1*2 allele but not increased among subjects with the SULT1A1*1/*1 genotype (odds ratio (OR) 2.1, 95% confidence interval (CI) 1.1-4.1 and OR 1.0, 95% CI 0.5-2.1, respectively). Colorectal cancer risk associated with 30+ pack-years of active smoking was higher among carriers of the SULT1A1*2 allele (OR 1.7, 95% CI 1.0-3.2) than among individuals with the SULT1A1*1/*1 genotype (OR 1.1, 95% CI 0.6-2.1). Our results do not support a main effect of SULT1A1 genotype with regard to colorectal cancer but suggest that individuals with the low activity SULT1A1*2 allele may be at higher risk following carcinogen exposure than those with the SULT1A1*1/*1 genotype.
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Affiliation(s)
- Carmen Lilla
- Division of Clinical Epidemiology, German Cancer Research Center, Heidelberg, Germany
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Brown K, Tompkins EM, White INH. Applications of accelerator mass spectrometry for pharmacological and toxicological research. MASS SPECTROMETRY REVIEWS 2006; 25:127-45. [PMID: 16059873 DOI: 10.1002/mas.20059] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The technique of accelerator mass spectrometry (AMS), known for radiocarbon dating of archeological specimens, has revolutionized high-sensitivity isotope detection in pharmacology and toxicology by allowing the direct determination of the amount of isotope in a sample rather than measuring its decay. It can quantify many isotopes, including 26Al, 14C, 41Ca, and 3H with detection down to attomole (10(-18)) amounts. Pharmacokinetic data in humans have been achieved with ultra-low levels of radiolabel. One of the most exciting biomedical applications of AMS with 14C-labeled potential carcinogens is the detection of modified proteins or DNA in tissues. The relationship between low-level exposure and covalent binding of genotoxic chemicals has been compared in rodents and humans. Such compounds include heterocyclic amines, benzene, and tamoxifen. Other applications range from measuring the absorption of 26Al to monitoring 41Ca turnover in bone. In epoxy-embedded tissue sections, high-resolution imaging of 14C label in cells is possible. The uses of AMS are becoming more widespread with the availability of instrumentation dedicated to the analysis of biomedical samples.
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Affiliation(s)
- Karen Brown
- Cancer Biomarkers and Prevention Group, Department of Cancer Studies and Molecular Medicine, The Biocentre, University of Leicester, Leicester LE1 7RH, United Kingdom
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48
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Cheung C, Ma X, Krausz KW, Kimura S, Feigenbaum L, Dalton TP, Nebert DW, Idle JR, Gonzalez FJ. Differential metabolism of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) in mice humanized for CYP1A1 and CYP1A2. Chem Res Toxicol 2005; 18:1471-8. [PMID: 16167840 DOI: 10.1021/tx050136g] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The procarcinogen 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is the most abundant heterocyclic amine formed during the cooking of foods. Metabolism of PhIP by CYP1A2 differs substantially between humans and rodents, with more N2-hydroxylation (activation) and less 4'-hydroxylation (detoxication) in humans. Therefore, the human response to PhIP and other heterocyclic amine exposure may not be accurately reflected in the laboratory rodent. By generating mouse models expressing the human genes, species differences in heterocyclic amine metabolism can be addressed. Two transgenic mouse lines were developed, one expressing the human CYP1A1 CYP1A2 transgene in a mouse Cyp1a1-null background (hCYP1A1) and another expressing human CYP1A1 CYP1A2 in a mouse Cyp1a2-null background (hCYP1A2). Expression of human CYP1A2 protein was detected in the liver and also at considerably lower levels in extrahepatic tissues such as lung, kidney, colon, and heart. In the hCYP1A1 and hCYP1A2 mice, 3-methylcholanthrene (3-MC) induced both human CYP1A1 and CYP1A2 protein in the liver. Differences in the metabolism of the heterocyclic amine PhIP were observed between wild-type and hCYP1A2 mice. PhIP was preferentially metabolized by N2-hydroxylation in hCYP1A2 mice, whereas in wild-type mice, 4'-hydroxylation was the predominant pathway. Since the N2-hydroxylation pathway for PhIP metabolism has been reported to be predominant in humans, these results illustrate the potential effectiveness of using these transgenic, humanized mice as models for determining human health risks to PhIP and other heterocyclic amines instead of wild-type mice.
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Affiliation(s)
- Connie Cheung
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
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DeGregorio MW, Dingley KH, Wurz GT, Ubick E, Turteltaub KW. Accelerator mass spectrometry allows for cellular quantification of doxorubicin at femtomolar concentrations. Cancer Chemother Pharmacol 2005; 57:335-42. [PMID: 16047147 DOI: 10.1007/s00280-005-0060-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2005] [Accepted: 05/30/2005] [Indexed: 10/25/2022]
Abstract
Accelerator mass spectrometry (AMS) is a highly sensitive analytical methodology used to quantify the content of radioisotopes, such as (14)C, in a sample. The primary goals of this work were to demonstrate the utility of AMS in determining total cellular [(14)C]anthracycline concentrations following administration of doxorubicin (DOX) and to develop a sensitive assay that is superior to high performance liquid chromatography (HPLC) for the quantification of [(14)C]anthracycline at the tumor level. In order to validate the sensitivity of AMS versus HPLC with fluorescence detection, we performed three studies comparing the cellular accumulation of DOX: one in vitro cell line study, and two in vivo xenograft mouse studies. Using AMS, we quantified cellular [(14)C]anthracycline content up to 4 h following in vitro exposure at concentrations ranging from 0.2 pg/ml (345 fM) to 2 microg/ml (3.45 microM) [(14)C]DOX. The results of this study show that, compared to standard fluorescence-based HPLC, the AMS method was over five orders of magnitude more sensitive. Two in vivo studies compared the sensitivity of AMS to HPLC using a nude mouse xenograft model in which breast cancer cells were implanted subcutaneously. After sufficiently large tumors formed, [(14)C]DOX was administered intravenously at two dose levels. Additionally, we tested the AMS method in a nude mouse xenograft model of multidrug resistance (MDR) in which each mouse was implanted with both wild type and MDR+ cells on opposite flanks. The results of the second and third studies showed that [(14)C]anthracycline concentrations were significantly higher in the wild type tumors compared to the MDR+ tumors, consistent with the MDR model. Although this method does not discriminate between parent drug and metabolites, the extreme sensitivity of AMS should facilitate similar studies in humans to establish target site drug delivery and to potentially determine the optimal treatment dose and regimen.
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MESH Headings
- Animals
- Antibiotics, Antineoplastic/administration & dosage
- Antibiotics, Antineoplastic/analysis
- Antibiotics, Antineoplastic/pharmacokinetics
- Carbon Radioisotopes/pharmacokinetics
- Cell Line, Tumor
- Chromatography, High Pressure Liquid/methods
- Dose-Response Relationship, Drug
- Doxorubicin/administration & dosage
- Doxorubicin/analysis
- Doxorubicin/pharmacokinetics
- Female
- Humans
- Liver/metabolism
- Mammary Neoplasms, Experimental/metabolism
- Mammary Neoplasms, Experimental/pathology
- Mass Spectrometry/methods
- Mice
- Mice, Inbred BALB C
- Mice, Nude
- Neoplasm Transplantation
- Reproducibility of Results
- Transplantation, Heterologous
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Affiliation(s)
- M W DeGregorio
- University of California, Davis, Department of Internal Medicine, Division of Hematology and Oncology, Cancer Center, Sacramento, 95817, USA.
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50
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Malfatti MA, Ubick EA, Felton JS. The impact of glucuronidation on the bioactivation and DNA adduction of the cooked-food carcinogen 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine in vivo. Carcinogenesis 2005; 26:2019-28. [PMID: 15944213 DOI: 10.1093/carcin/bgi151] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
UDP-glucuronosyltransferases (UGTs) catalyze the glucuronidation of many different chemicals. Glucuronidation is especially important for detoxifying reactive intermediates from metabolic reactions, which otherwise can be biotransformed into highly reactive cytotoxic or carcinogenic species. Detoxification of certain food-borne-carcinogenic heterocyclic amines (HAs) is highly dependent on UGT1A-mediated glucuronidation. 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), the most mass abundant carcinogenic HA found in well-done cooked meat, is extensively glucuronidated by UGT1A proteins. In humans, CYP1A2 catalyzed N-hydroxylation and subsequent UGT1A-mediated glucuronidation is a dominant pathway in the metabolism of PhIP. Therefore, changes in glucuronidation rates could significantly alter PhIP metabolism. To determine the importance of UGT1A-mediated glucuronidation in the biotransformation of PhIP, hepatic UGT1A deficient Gunn and UGT1A proficient Wistar rats were exposed to a 100 microg/kg oral dose of [(14)C]PhIP. Urine was collected over 24 h and the PhIP urinary metabolite profiles were compared between the two strains. After the 24 h exposure, livers and colons were removed and analyzed for DNA adduct formation by accelerator mass spectrometry. Wistar rats produced several PhIP and N-hydroxy-PhIP glucuronides that accounted for approximately 25% of the total amount of recovered urinary metabolites. In the Gunn rats, PhIP and N-hydroxy-PhIP glucuronides were reduced by 68-92%, compared with the Wistar rats. PhIP-DNA adduct analysis from the Gunn rats revealed a correlation between reduced urinary PhIP and N-hydroxy-PhIP glucuronide levels and increased hepatic DNA adducts, compared with the Wistar rats. In the colon, DNA adduct levels were lower in the Gunn rats compared with the Wistar rats, suggesting deficient hepatic UGT1A activity provides protection against DNA adduct formation in peripheral tissue. Due to differences in PhIP metabolism between humans and rodents, extrapolation of these results to the human situation must be done with caution. These results indicate that UGT1A-mediated glucuronidation of PhIP and N-hydroxy-PhIP is an important pathway for PhIP detoxification, and demonstrate the importance of tissue-specific metabolism. Tissues with reduced UGT1A activity can have a higher rate of PhIP activation and be more inclined to form DNA adducts compared with tissues with normal UGT1A activity.
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Affiliation(s)
- Michael A Malfatti
- Biosciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94551, USA
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