1
|
Francis S, Kortei NK, Sackey M, Richard SA. Aflatoxin B 1 induces infertility, fetal deformities, and potential therapies. Open Med (Wars) 2024; 19:20240907. [PMID: 38283584 PMCID: PMC10818061 DOI: 10.1515/med-2024-0907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 12/15/2023] [Accepted: 01/06/2024] [Indexed: 01/30/2024] Open
Abstract
Aflatoxin B1 (AFB1) is a subsidiary poisonous metabolite, archetypally spawned by Aspergillus flavus and A. parasiticus, which are often isolated in warm or tropical countries across the world. AFB1 is capable of disrupting the functioning of several reproductive endocrine glands by interrupting the enzymes and their substrates that are liable for the synthesis of various hormones in both males and females. In men, AFB1 is capable of hindering testicular development, testicular degeneration, and reduces reproductive capabilities. In women, a direct antagonistic interaction of AFB1 with steroid hormone receptors influencing gonadal hormone production of estrogen and progesterone was responsible for AFB1-associated infertility. AFB1 is potentially teratogenic and is responsible for the development of malformation in humans and animals. Soft-tissue anomalies such as internal hydrocephalus, microphthalmia, cardiac defects, augmented liver lobes, reproductive changes, immune modifications, behavioral changes and predisposition of animals and humans to neoplasm development are AFB1-associated anomalies. Substances such as esculin, selenium, gynandra extract, vitamins C and E, oltipraz, and CDDO-Im are potential therapies for AFB1. Thus, this review elucidates the pivotal pathogenic roles of AFB1 in infertility, fetal deformities, and potential therapies because AFB1 toxicity is a key problem globally.
Collapse
Affiliation(s)
- Sullibie Francis
- Department of Obstetrics and Gynecology, Ho Teaching Hospital, P.O. Box MA-374, Ho, Ghana
| | - Nii Korley Kortei
- Department of Nutrition and Dietetics, School of Allied Health Sciences, University of Health and Allied Sciences, Ho, Ghana
| | - Marian Sackey
- Department of Pharmacy, Ho Teaching Hospital, P.O. Box MA-374, Ho, Ghana
| | - Seidu A. Richard
- Department of Medicine, Princefield University, P. O. Box MA128, Ho, Ghana
| |
Collapse
|
2
|
Bogen KT. Ultrasensitive dose-response for asbestos cancer risk implied by new inflammation-mutation model. ENVIRONMENTAL RESEARCH 2023; 230:115047. [PMID: 36965808 DOI: 10.1016/j.envres.2022.115047] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Accepted: 12/09/2022] [Indexed: 05/30/2023]
Abstract
Alterations in complex cellular phenotype each typically involve multistep activation of an ultrasensitive molecular switch (e.g., to adaptively initiate an apoptosis, inflammasome, Nrf2-ARE anti-oxidant, or heat-shock activation pathway) that triggers expression of a suite of target genes while efficiently limiting false-positive switching from a baseline state. Such switches exhibit nonlinear signal-activation relationships. In contrast, a linear no-threshold (LNT) dose-response relationship is expected for damage that accumulates in proportion to dose, as hypothesized for increased risk of cancer in relation to genotoxic dose according to the multistage somatic mutation/clonal-expansion theory of cancer, e.g., as represented in the Moolgavkar-Venzon-Knudsen (MVK) cancer model by a doubly stochastic nonhomogeneous Poisson process. Mesothelioma and lung cancer induced by exposure to carcinogenic (e.g., certain asbestos) fibers in humans and experimental animals are thought to involve modes of action driven by mutations, cytotoxicity-associated inflammation, or both, rendering ambiguous expectations concerning the nature of model-implied shape of the low-dose response for above-background increase in risk of incurring these endpoints. A recent Inflammation Somatic Mutation (ISM) theory of cancer posits instead that tissue-damage-associated inflammation that epigenetically recruits, activates and orchestrates stem cells to engage in tissue repair does not merely promote cancer, but rather is a requisite co-initiator (acting together with as few as two somatic mutations) of the most efficient pathway to any type of cancer in any reparable tissue (Dose-Response 2019; 17(2):1-12). This theory is reviewed, implications of this theory are discussed in relation to mesothelioma and lung cancer associated with chronic asbestos inhalation, one of the two types of ISM-required mutations is here hypothesized to block or impede inflammation resolution (e.g., by doing so for GPCR-mediated signal transduction by one or more endogenous autacoid specialized pro-resolving mediators or SPMs), and supporting evidence for this hypothesis is discussed.
Collapse
Affiliation(s)
- Kenneth T Bogen
- 9832 Darcy Forest Drive, Silver Spring, MD, 20910, United States.
| |
Collapse
|
3
|
Wang R, Liang L, Matsumoto M, Iwata K, Umemura A, He F. Reactive Oxygen Species and NRF2 Signaling, Friends or Foes in Cancer? Biomolecules 2023; 13:biom13020353. [PMID: 36830722 PMCID: PMC9953152 DOI: 10.3390/biom13020353] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 02/03/2023] [Accepted: 02/09/2023] [Indexed: 02/17/2023] Open
Abstract
The imbalance between reactive oxygen species (ROS) production and clearance causes oxidative stress and ROS, which play a central role in regulating cell and tissue physiology and pathology. Contingent upon concentration, ROS influence cancer development in contradictory ways, either stimulating cancer survival and growth or causing cell death. Cells developed evolutionarily conserved programs to sense and adapt redox the fluctuations to regulate ROS as either signaling molecules or toxic insults. The transcription factor nuclear factor erythroid 2-related factor 2 (NRF2)-KEAP1 system is the master regulator of cellular redox and metabolic homeostasis. NRF2 has Janus-like roles in carcinogenesis and cancer development. Short-term NRF2 activation suppresses tissue injury, inflammation, and cancer initiation. However, cancer cells often exhibit constitutive NRF2 activation due to genetic mutations or oncogenic signaling, conferring advantages for cancer cells' survival and growth. Emerging evidence suggests that NRF2 hyperactivation, as an adaptive cancer phenotype under stressful tumor environments, regulates all hallmarks of cancer. In this review, we summarized the source of ROS, regulation of ROS signaling, and cellular sensors for ROS and oxygen (O2), we reviewed recent progress on the regulation of ROS generation and NRF2 signaling with a focus on the new functions of NRF2 in cancer development that reach beyond what we originally envisioned, including regulation of cancer metabolism, autophagy, macropinocytosis, unfolded protein response, proteostasis, and circadian rhythm, which, together with anti-oxidant and drug detoxification enzymes, contributes to cancer development, metastasis, and anticancer therapy resistance.
Collapse
Affiliation(s)
- Ruolei Wang
- The Center for Cancer Research, Academy of Integrative Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Lirong Liang
- Department of Respiratory and Critical Care Medicine, Beijing Institute of Respiratory Medicine and Beijing Chao-Yang Hospital, Capital Medical University, Beijing 100020, China
| | - Misaki Matsumoto
- Department of Pharmacology, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
| | - Kazumi Iwata
- Department of Pharmacology, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
| | - Atsushi Umemura
- Department of Pharmacology, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
- Correspondence: (A.U.); (F.H.); Tel.: +75-251-5332 (A.U.); +86-21-5132-2501 (F.H.)
| | - Feng He
- The Center for Cancer Research, Academy of Integrative Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
- Correspondence: (A.U.); (F.H.); Tel.: +75-251-5332 (A.U.); +86-21-5132-2501 (F.H.)
| |
Collapse
|
4
|
Ates MB, Ortatatli M, Oguz H, Ozdemir O, Terzi F, Ciftci MK, Hatipoglu F. The ameliorative effects of Nigella sativa, thymoquinone, and bentonite against aflatoxicosis in broilers via AFAR and Nrf2 signalling pathways, and down-regulation of caspase-3. Br Poult Sci 2021; 63:332-339. [PMID: 34738498 DOI: 10.1080/00071668.2021.1998366] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
1. Aflatoxins' (AFs) are metabolites which especially have toxic effects on proteins, and are detoxified by the aflatoxin-B1 aldehyde reductase (AFAR) pathway. In this pathway, the aldo-keto reductase family 7, member A2 (AKR7A2) enzyme is controlled by nucleic-related erythroid factor 2 (Nrf2) plays an active role. However, data on the efficacy of this critical pathway in broilers is limited.2. The aim of the following study was the changes in the expression levels of AKR7A2, Nrf2, and caspase-3, and the effects of Nigella sativa seeds (NS), thymoquinone (TMQ), and bentonite (BNT) on expression were investigated in broilers exposed to AFs.3. One-hundred broilers were divided into ten groups (control (CNT); AF; NS; TMQ; BNT; AF+TMQ; AF+NS; AF+BNT; AF+BNT+NS; AF+BNT+TMQ) and fed for 28 d. AF. TMQ, NS and BNT were added to diets at levels of 2 mg/kg, 300 mg/kg, 50 g/kg and 10 g/kg respectively.4. The addition of AF to the diet decreased AKR7A2 and Nrf2 levels dramatically, but increased caspase-3 (P<0.01). TMQ, NS and BNT additions to the diet eliminated all negative effects caused by AF (P<0.01); and AKR7A2 and Nrf2 were further raised in TMQ and NS groups when compared to the control group. TMQ and NS showed a positive effect on detoxification parameters when given together with BNT.5. Supplementation with NS and TMQ enhanced AF detoxification via the AFAR pathway, by increasing AKR7A2 and Nrf2 levels, in addition to reducing hepatocyte apoptosis.
Collapse
Affiliation(s)
- Mehmet Burak Ates
- Selcuk University, Faculty of Veterinary Medicine, Department of Pathology, TR-42130, Konya, Turkey
| | - Mustafa Ortatatli
- Selcuk University, Faculty of Veterinary Medicine, Department of Pathology, TR-42130, Konya, Turkey
| | - Halis Oguz
- Selcuk University, Faculty of Veterinary Medicine, Department of Pharmacology and Toxicology, TR-42130, Konya, Turkey
| | - Ozgur Ozdemir
- Selcuk University, Faculty of Veterinary Medicine, Department of Pathology, TR-42130, Konya, Turkey
| | - Funda Terzi
- Kastamonu University, Faculty of Veterinary Medicine, Department of Pathology, TR-37200, Kastamonu, Turkey
| | - Mustafa Kemal Ciftci
- Istanbul Aydın University, Faculty of Dentistry, Department of Basic Sciences TR-34295, Istanbul, Turkey
| | - Fatih Hatipoglu
- Selcuk University, Faculty of Veterinary Medicine, Department of Pathology, TR-42130, Konya, Turkey.,Kyrgyz-Turkish Manas University, Faculty of Veterinary Medicine, Department of Pathology, KG-720044, Bishkek, Kyrgyzstan
| |
Collapse
|
5
|
Apolinário LA, Ramalho LNZ, Moosavi MH, Jager AV, Augusto MJ, Trotta MR, Petta T, Khaneghah AM, Oliveira CAF, Ramalho FS. Oncogenic and tumor suppressor pathways in subchronic aflatoxicosis in rats: Association with serum and urinary aflatoxin exposure biomarkers. Food Chem Toxicol 2021; 153:112263. [PMID: 34015426 DOI: 10.1016/j.fct.2021.112263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 04/29/2021] [Accepted: 05/10/2021] [Indexed: 11/17/2022]
Abstract
In this study, the changes in oncogenic and tumor suppressor signaling pathways in liver and their association with serum and urinary biomarkers of aflatoxin exposure were evaluated in Wistar rats fed diets containing aflatoxin B1 (AFB1) for 90 days. Rats were divided into four groups (n = 15 per group) and assigned to dietary treatments containing 0 (control), 50 (AFB50), 100 (AFB100) and 200 μg AFB1 kg-1 diet (AFB200). Multiple preneoplastic foci of hepatocytes marked with glutathione-S-transferase-placental form (GST-P) were identified in AFB100 and AFB200 groups. Hepatocellular damage induced by AFB1 resulted in overexpression of cyclin D1 and β-catenin. The liver expression of retinoblastoma (Rb) and p27Kip1 decreased in AFB100 and AFB200 groups, confirming the favorable conditions for neoplastic progression to hepatocellular carcinoma. All samples from rats fed AFB1-contaminated diets had quantifiable AFB1-lysine in serum or urinary AFM1 and AFB1-N7-guanine, with mean levels of 20.42-50.34 ng mL-1, 5.31-37.68 and 39.15-126.37 ng mg-1 creatinine, respectively. Positive correlations were found between AFB1-lysine, AFM1 or AFB1-N7-guanine and GST-P+, β-catenin+ and cyclin D1+ hepatocytes, while Rb + cells negatively correlated with those AFB1 exposure biomarkers. The pathways evaluated are critical molecular mechanisms of AFB1-induced hepatocarcinogenesis in rats.
Collapse
Affiliation(s)
- Letícia A Apolinário
- Department of Pathology and Legal Medicine, School of Medicine at Ribeirão Preto, University of São Paulo, Av. do Café, s/n, CEP, 14040-903, Ribeirão Preto, SP, Brazil
| | - Leandra N Z Ramalho
- Department of Pathology and Legal Medicine, School of Medicine at Ribeirão Preto, University of São Paulo, Av. do Café, s/n, CEP, 14040-903, Ribeirão Preto, SP, Brazil
| | - Motahareh Hashemi Moosavi
- Department of Food Science and Technology, National Nutrition and Food Technology Research Institute, Faculty of Nutrition Sciences and Food Technology, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Alessandra V Jager
- Department of Bio Molecular Sciences, School of Pharmaceutical Sciences at Ribeirão Preto, University of São Paulo, Av. do Café, s/n, CEP, 14040-903, Ribeirão Preto, SP, Brazil
| | - Marlei J Augusto
- Department of Pathology and Legal Medicine, School of Medicine at Ribeirão Preto, University of São Paulo, Av. do Café, s/n, CEP, 14040-903, Ribeirão Preto, SP, Brazil
| | - Maurício R Trotta
- Department of Pathology and Legal Medicine, School of Medicine at Ribeirão Preto, University of São Paulo, Av. do Café, s/n, CEP, 14040-903, Ribeirão Preto, SP, Brazil
| | - Tânia Petta
- Actinobac Agrosciences. Supera - Parque de Inovação e Tecnologia de Ribeirão Preto, Av. Dra. Nadir Águiar, 1805, CEP, 14056-680, Ribeirão Preto, SP, Brazil
| | - Amin Mousavi Khaneghah
- Department of Food Science, Faculty of Food Engineering, University of Campinas (UNICAMP). R. Monteiro Lobato, 80, CEP, 13083-862, Campinas, SP, Brazil
| | - Carlos A F Oliveira
- Department of Food Engineering, School of Animal Science and Food Engineering, University of São Paulo. Av. Duque de Caxias Norte, 225, CEP, 13635-900, Pirassununga, SP, Brazil.
| | - Fernando S Ramalho
- Department of Pathology and Legal Medicine, School of Medicine at Ribeirão Preto, University of São Paulo, Av. do Café, s/n, CEP, 14040-903, Ribeirão Preto, SP, Brazil
| |
Collapse
|
6
|
Egbujor MC, Saha S, Buttari B, Profumo E, Saso L. Activation of Nrf2 signaling pathway by natural and synthetic chalcones: a therapeutic road map for oxidative stress. Expert Rev Clin Pharmacol 2021; 14:465-480. [PMID: 33691555 DOI: 10.1080/17512433.2021.1901578] [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: 02/07/2023]
Abstract
Introduction:Nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway plays a key role in diverse gene expressions responsible for protection against oxidative stress and xenobiotics. Chalcones with a common chemical scaffold of 1,3-diaryl-2- propen-1-one, are abundantly present in nature with a wide variety of pharmacological properties. This review will discuss the interactions of natural and synthetic chalcones with Nrf2 signaling.Areas covered:Chalcones are reportedly found to activate Nrf2 signaling pathway, expression of Nrf2-regulated antioxidant genes, induce cytoprotective proteins and upregulate multidrug resistance-associated proteins. Chalcones being soft electrophiles are less prone to hostile off-target effects and unlikely to induce carcinogenicity and mutagenicity. Furthermore, their low toxicity, structural diversity, feasibility in structural reorganization and the presence of α,β-unsaturated carbonyl group which makes them suitable drug candidates targeting Nrf2-dependent diseases.Expert opinion:Nrf2-Keap1 signaling pathway plays a central role in redox signaling. However, available therapeutic agents for Nrf2 activation have limited practical applications due to their associated risks, relatively low efficacy and bioavailability. The designing and fabrication of new chemical entities with chalcone scaffold-based Michael acceptor mechanism should be aimed as potential therapeutic Nrf2 activators to target oxidative stress and inflammation-mediated diseases such as atherosclerosis, Parkinson's disease and many more.
Collapse
Affiliation(s)
- Melford Chuka Egbujor
- Department of Industrial Chemistry, Renaissance University, Ugbawka, Enugu State, Nigeria
| | - Sarmistha Saha
- Department of Cardiovascular and Endocrine-Metabolic Diseases, and Aging, Italian National Institute of Health, Rome, Italy
| | - Brigitta Buttari
- Department of Cardiovascular and Endocrine-Metabolic Diseases, and Aging, Italian National Institute of Health, Rome, Italy
| | - Elisabetta Profumo
- Department of Cardiovascular and Endocrine-Metabolic Diseases, and Aging, Italian National Institute of Health, Rome, Italy
| | - Luciano Saso
- Department of Physiology and Pharmacology "Vittorio Erspamer, Sapienza University of Rome, Rome, Italy
| |
Collapse
|
7
|
Mondal D, Narwani D, Notta S, Ghaffar D, Mardhekar N, Quadri SSA. Oxidative stress and redox signaling in CRPC progression: therapeutic potential of clinically-tested Nrf2-activators. CANCER DRUG RESISTANCE (ALHAMBRA, CALIF.) 2021; 4:96-124. [PMID: 35582006 PMCID: PMC9019181 DOI: 10.20517/cdr.2020.71] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 11/06/2020] [Accepted: 11/11/2020] [Indexed: 12/14/2022]
Abstract
Androgen deprivation therapy (ADT) is the mainstay regimen in patients with androgen-dependent prostate cancer (PCa). However, the selection of androgen-independent cancer cells leads to castrate resistant prostate cancer (CRPC). The aggressive phenotype of CRPC cells underscores the need to elucidate mechanisms and therapeutic strategies to suppress CRPC outgrowth. Despite ADT, the activation of androgen receptor (AR) transcription factor continues via crosstalk with parallel signaling pathways. Understanding of how these signaling cascades are initiated and amplified post-ADT is lacking. Hormone deprivation can increase oxidative stress and the resultant reactive oxygen species (ROS) may activate both AR and non-AR signaling. Moreover, ROS-induced inflammatory cytokines may further amplify these redox signaling pathways to augment AR function. However, clinical trials using ROS quenching small molecule antioxidants have not suppressed CRPC progression, suggesting that more potent and persistent suppression of redox signaling in CRPC cells will be needed. The transcription factor Nrf2 increases the expression of numerous antioxidant enzymes and downregulates the function of inflammatory transcription factors, e.g., nuclear factor kappa B. We documented that Nrf2 overexpression can suppress AR-mediated transcription in CRPC cell lines. Furthermore, two Nrf2 activating agents, sulforaphane (a phytochemical) and bardoxolone-methyl (a drug in clinical trial) suppress AR levels and sensitize CRPC cells to anti-androgens. These observations implicate the benefits of potent Nrf2-activators to suppress the lethal signaling cascades that lead to CRPC outgrowth. This review article will address the redox signaling networks that augment AR signaling during PCa progression to CRPC, and the possible utility of Nrf2-activating agents as an adjunct to ADT.
Collapse
Affiliation(s)
- Debasis Mondal
- Debusk College of Osteopathic Medicine, Lincoln Memorial University, Knoxville, TN 37932, USA
| | - Devin Narwani
- Debusk College of Osteopathic Medicine, Lincoln Memorial University, Knoxville, TN 37932, USA
| | - Shahnawaz Notta
- Debusk College of Osteopathic Medicine, Lincoln Memorial University, Knoxville, TN 37932, USA
| | - Dawood Ghaffar
- Debusk College of Osteopathic Medicine, Lincoln Memorial University, Knoxville, TN 37932, USA
| | - Nikhil Mardhekar
- Debusk College of Osteopathic Medicine, Lincoln Memorial University, Knoxville, TN 37932, USA
| | - Syed S A Quadri
- Debusk College of Osteopathic Medicine, Lincoln Memorial University, Knoxville, TN 37932, USA
| |
Collapse
|
8
|
Fishbein A, Hammock BD, Serhan CN, Panigrahy D. Carcinogenesis: Failure of resolution of inflammation? Pharmacol Ther 2021; 218:107670. [PMID: 32891711 PMCID: PMC7470770 DOI: 10.1016/j.pharmthera.2020.107670] [Citation(s) in RCA: 87] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/19/2020] [Indexed: 02/06/2023]
Abstract
Inflammation in the tumor microenvironment is a hallmark of cancer and is recognized as a key characteristic of carcinogens. However, the failure of resolution of inflammation in cancer is only recently being understood. Products of arachidonic acid and related fatty acid metabolism called eicosanoids, including prostaglandins, leukotrienes, lipoxins, and epoxyeicosanoids, critically regulate inflammation, as well as its resolution. The resolution of inflammation is now appreciated to be an active biochemical process regulated by endogenous specialized pro-resolving lipid autacoid mediators which combat infections and stimulate tissue repair/regeneration. Environmental and chemical human carcinogens, including aflatoxins, asbestos, nitrosamines, alcohol, and tobacco, induce tumor-promoting inflammation and can disrupt the resolution of inflammation contributing to a devastating global cancer burden. While mechanisms of carcinogenesis have focused on genotoxic activity to induce mutations, nongenotoxic mechanisms such as inflammation and oxidative stress promote genotoxicity, proliferation, and mutations. Moreover, carcinogens initiate oxidative stress to synergize with inflammation and DNA damage to fuel a vicious feedback loop of cell death, tissue damage, and carcinogenesis. In contrast, stimulation of resolution of inflammation may prevent carcinogenesis by clearance of cellular debris via macrophage phagocytosis and inhibition of an eicosanoid/cytokine storm of pro-inflammatory mediators. Controlling the host inflammatory response and its resolution in carcinogen-induced cancers will be critical to reducing carcinogen-induced morbidity and mortality. Here we review the recent evidence that stimulation of resolution of inflammation, including pro-resolution lipid mediators and soluble epoxide hydrolase inhibitors, may be a new chemopreventive approach to prevent carcinogen-induced cancer that should be evaluated in humans.
Collapse
Affiliation(s)
- Anna Fishbein
- Center for Vascular Biology Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA; Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.
| | - Bruce D. Hammock
- Department of Entomology and Nematology, and UCD Comprehensive Cancer Center, University of California, Davis, CA 95616, USA
| | - Charles N. Serhan
- Center for Experimental Therapeutics and Reperfusion Injury, Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Dipak Panigrahy
- Center for Vascular Biology Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA,Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| |
Collapse
|
9
|
Taguchi K, Yamamoto M. The KEAP1-NRF2 System as a Molecular Target of Cancer Treatment. Cancers (Basel) 2020; 13:cancers13010046. [PMID: 33375248 PMCID: PMC7795874 DOI: 10.3390/cancers13010046] [Citation(s) in RCA: 84] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 12/21/2020] [Accepted: 12/22/2020] [Indexed: 12/15/2022] Open
Abstract
Simple Summary Nuclear factor erythroid-derived 2-like 2 (encoded by the Nfe2l2 gene; NRF2) is a transcription factor that regulates a variety of cytoprotective genes, including antioxidant enzymes, detoxification enzymes, inflammation-related proteins, drug transporters and metabolic enzymes. NRF2 is regulated by unique molecular mechanisms that stem from Kelch-like ECH-associated protein 1 (KEAP1) in response to oxidative and electrophilic stresses. It has been shown that disturbance or perturbation of the NRF2 activation causes and/or exacerbates many kinds of diseases. On the contrary, aberrant activations of NRF2 also provoke intriguing pathologic features, especially in cancers. Cancer cells with high NRF2 activity have been referred to as NRF2-addicted cancers, which are frequently found in lung cancers. In this review, we summarize the current accomplishments of the KEAP1–NRF2 pathway analyses in special reference to the therapeutic target of cancer therapy. The concept of synthetic lethality provides a new therapeutic approach for NRF2-addicted cancers. Abstract The Kelch-like ECH-associated protein 1 (KEAP1)—Nuclear factor erythroid-derived 2-like 2 (encoded by the Nfe2l2 gene; NRF2) system attracts extensive interest from scientists in basic and clinical cancer research fields, as NRF2 exhibits activity as both an oncogene and tumor suppressor, depending on the context. Especially unique and malignant, NRF2-addicted cancers exhibit high levels of NRF2 expression. Somatic mutations identified in the NRF2 or KEAP1 genes of NRF2-addicted cancers cause the stabilization and accumulation of NRF2. NRF2-addicted cancers hijack the intrinsic roles that NRF2 plays in cytoprotection, including antioxidative and anti-electrophilic responses, as well as metabolic reprogramming, and acquire a marked advantage to survive under severe and limited microenvironments. Therefore, NRF2 inhibitors are expected to have therapeutic effects in patients with NRF2-addicted cancers. In contrast, NRF2 activation in host immune cells exerts significant suppression of cancer cell growth, indicating that NRF2 inducers also have the potential to be therapeutics for cancers. Thus, the KEAP1–NRF2 system makes a broad range of contributions to both cancer development and suppression. These observations thus demonstrate that both NRF2 inhibitors and inducers are useful for the treatment of cancers with high NRF2 activity.
Collapse
Affiliation(s)
- Keiko Taguchi
- Department of Medical Biochemistry, Graduate School of Medicine, Tohoku University, Sendai 980-8575, Japan;
- Department of Medical Biochemistry, Tohoku Medical Megabank Organization, Tohoku University, Sendai 980-8573, Japan
- Advanced Research Center for Innovations in Next-Generation Medicine (INGEM), Tohoku University, Sendai 980-8573, Japan
| | - Masayuki Yamamoto
- Department of Medical Biochemistry, Graduate School of Medicine, Tohoku University, Sendai 980-8575, Japan;
- Department of Medical Biochemistry, Tohoku Medical Megabank Organization, Tohoku University, Sendai 980-8573, Japan
- Advanced Research Center for Innovations in Next-Generation Medicine (INGEM), Tohoku University, Sendai 980-8573, Japan
- Correspondence: ; Tel.: +81-22-728-3039
| |
Collapse
|
10
|
He F, Antonucci L, Karin M. NRF2 as a regulator of cell metabolism and inflammation in cancer. Carcinogenesis 2020; 41:405-416. [PMID: 32347301 DOI: 10.1093/carcin/bgaa039] [Citation(s) in RCA: 147] [Impact Index Per Article: 36.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 04/11/2020] [Accepted: 04/21/2020] [Indexed: 12/14/2022] Open
Abstract
Nuclear factor erythroid 2-related factor 2 (NRF2) is a master transcriptional regulator of genes whose products defend our cells for toxic and oxidative insults. Although NRF2 activation may reduce cancer risk by suppressing oxidative stress and tumor-promoting inflammation, many cancers exhibit elevated NRF2 activity either due to mutations that disrupt the negative control of NRF2 activity or other factors. Importantly, NRF2 activation is associated with poor prognosis and NRF2 has turned out to be a key activator of cancer-supportive anabolic metabolism. In this review, we summarize the diverse roles played by NRF2 in cancer focusing on metabolic reprogramming and tumor-promoting inflammation.
Collapse
Affiliation(s)
- Feng He
- Laboratory of Gene Regulation and Signal Transduction, Department of Pharmacology, School of Medicine, San Diego, La Jolla, CA, USA
| | - Laura Antonucci
- Laboratory of Gene Regulation and Signal Transduction, Department of Pharmacology, School of Medicine, San Diego, La Jolla, CA, USA
| | - Michael Karin
- Laboratory of Gene Regulation and Signal Transduction, Department of Pharmacology, School of Medicine, San Diego, La Jolla, CA, USA.,Department of Pathology, School of Medicine, University of California, San Diego, La Jolla, CA, USA
| |
Collapse
|
11
|
Meng X, Waddington JC, Tailor A, Lister A, Hamlett J, Berry N, Park BK, Sporn MB. CDDO-imidazolide Targets Multiple Amino Acid Residues on the Nrf2 Adaptor, Keap1. J Med Chem 2020; 63:9965-9976. [PMID: 32787104 DOI: 10.1021/acs.jmedchem.0c01088] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Synthetic triterpenoids including CDDO, its methyl ester (CDDO-Me, bardoxolone methyl), and its imidazolide (CDDO-Im) enhance Nrf2-mediated antioxidant and anti-inflammatory activity in many diseases by reacting with thiols on the adaptor protein, Keap1. Unlike monofunctional CDDO-Me, the bifunctional analog, CDDO-Im, has a second reactive site (imidazolide) and can covalently bind to amino acids other than cysteine on target proteins such as glutathione S-transferase pi (GSTP), serum albumin, or Keap1. Here we show for the first time that bifunctional CDDO-Im (in contrast to CDDO-Me), as low as 50 nM, can covalently transacylate arginine and serine residues in GSTP and cross-link them to adjacent cysteine residues. Moreover, we show that CDDO-Im binds covalently to Keap1 by forming permanent Michael adducts with eight different cysteines, and acyl adducts with lysine and several tyrosine residues. Modeling studies suggest that the Tyr 85 adduct stabilizes the Keap1-Cul3 complex, thereby enhancing the potency of CDDO-Im.
Collapse
Affiliation(s)
- Xiaoli Meng
- MRC Centre for Drug Safety Science, Department of Molecular & Clinical Pharmacology, University of Liverpool, Liverpool L69 3GE, U.K
| | - James C Waddington
- MRC Centre for Drug Safety Science, Department of Molecular & Clinical Pharmacology, University of Liverpool, Liverpool L69 3GE, U.K
| | - Arun Tailor
- MRC Centre for Drug Safety Science, Department of Molecular & Clinical Pharmacology, University of Liverpool, Liverpool L69 3GE, U.K
| | - Adam Lister
- MRC Centre for Drug Safety Science, Department of Molecular & Clinical Pharmacology, University of Liverpool, Liverpool L69 3GE, U.K
| | - Jane Hamlett
- MRC Centre for Drug Safety Science, Department of Molecular & Clinical Pharmacology, University of Liverpool, Liverpool L69 3GE, U.K
| | - Neil Berry
- Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, U.K
| | - B Kevin Park
- MRC Centre for Drug Safety Science, Department of Molecular & Clinical Pharmacology, University of Liverpool, Liverpool L69 3GE, U.K
| | - Michael B Sporn
- Molecular and Systems Biology, Dartmouth Medical School, Lebanon, New Hampshire 03756, United States
| |
Collapse
|
12
|
Resolution of eicosanoid/cytokine storm prevents carcinogen and inflammation-initiated hepatocellular cancer progression. Proc Natl Acad Sci U S A 2020; 117:21576-21587. [PMID: 32801214 DOI: 10.1073/pnas.2007412117] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Toxic environmental carcinogens promote cancer via genotoxic and nongenotoxic pathways, but nongenetic mechanisms remain poorly characterized. Carcinogen-induced apoptosis may trigger escape from dormancy of microtumors by interfering with inflammation resolution and triggering an endoplasmic reticulum (ER) stress response. While eicosanoid and cytokine storms are well-characterized in infection and inflammation, they are poorly characterized in cancer. Here, we demonstrate that carcinogens, such as aflatoxin B1 (AFB1), induce apoptotic cell death and the resulting cell debris stimulates hepatocellular carcinoma (HCC) tumor growth via an "eicosanoid and cytokine storm." AFB1-generated debris up-regulates cyclooxygenase-2 (COX-2), soluble epoxide hydrolase (sEH), ER stress-response genes including BiP, CHOP, and PDI in macrophages. Thus, selective cytokine or eicosanoid blockade is unlikely to prevent carcinogen-induced cancer progression. Pharmacological abrogation of both the COX-2 and sEH pathways by PTUPB prevented the debris-stimulated eicosanoid and cytokine storm, down-regulated ER stress genes, and promoted macrophage phagocytosis of debris, resulting in suppression of HCC tumor growth. Thus, inflammation resolution via dual COX-2/sEH inhibition is an approach to prevent carcinogen-induced cancer.
Collapse
|
13
|
Yagishita Y, Gatbonton-Schwager TN, McCallum ML, Kensler TW. Current Landscape of NRF2 Biomarkers in Clinical Trials. Antioxidants (Basel) 2020; 9:antiox9080716. [PMID: 32784785 PMCID: PMC7464243 DOI: 10.3390/antiox9080716] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 08/02/2020] [Accepted: 08/05/2020] [Indexed: 12/12/2022] Open
Abstract
The transcription factor NF-E2 p45-related factor 2 (NRF2; encoded by NFE2L2) plays a critical role in the maintenance of cellular redox and metabolic homeostasis, as well as the regulation of inflammation and cellular detoxication pathways. The contribution of the NRF2 pathway to organismal homeostasis is seen in many studies using cell lines and animal models, raising intense attention towards targeting its clinical promise. Over the last three decades, an expanding number of clinical studies have examined NRF2 inducers targeting an ever-widening range of diseases. Full understanding of the pharmacokinetic and pharmacodynamic properties of drug candidates rely partly on the identification, validation, and use of biomarkers to optimize clinical applications. This review focuses on results from clinical trials with four agents known to target NRF2 signaling in preclinical studies (dimethyl fumarate, bardoxolone methyl, oltipraz, and sulforaphane), and evaluates the successes and limitations of biomarkers focused on expression of NRF2 target genes and others, inflammation and oxidative stress biomarkers, carcinogen metabolism and adduct biomarkers in unavoidably exposed populations, and targeted and untargeted metabolomics. While no biomarkers excel at defining pharmacodynamic actions in this setting, it is clear that these four lead clinical compounds do touch the NRF2 pathway in humans.
Collapse
|
14
|
Schrenk D, Bignami M, Bodin L, Chipman JK, del Mazo J, Grasl‐Kraupp B, Hogstrand C, Hoogenboom L(R, Leblanc J, Nebbia CS, Nielsen E, Ntzani E, Petersen A, Sand S, Schwerdtle T, Vleminckx C, Marko D, Oswald IP, Piersma A, Routledge M, Schlatter J, Baert K, Gergelova P, Wallace H. Risk assessment of aflatoxins in food. EFSA J 2020; 18:e06040. [PMID: 32874256 PMCID: PMC7447885 DOI: 10.2903/j.efsa.2020.6040] [Citation(s) in RCA: 112] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
EFSA was asked to deliver a scientific opinion on the risks to public health related to the presence of aflatoxins in food. The risk assessment was confined to aflatoxin B1 (AFB1), AFB2, AFG1, AFG2 and AFM1. More than 200,000 analytical results on the occurrence of aflatoxins were used in the evaluation. Grains and grain-based products made the largest contribution to the mean chronic dietary exposure to AFB1 in all age classes, while 'liquid milk' and 'fermented milk products' were the main contributors to the AFM1 mean exposure. Aflatoxins are genotoxic and AFB1 can cause hepatocellular carcinomas (HCCs) in humans. The CONTAM Panel selected a benchmark dose lower confidence limit (BMDL) for a benchmark response of 10% of 0.4 μg/kg body weight (bw) per day for the incidence of HCC in male rats following AFB1 exposure to be used in a margin of exposure (MOE) approach. The calculation of a BMDL from the human data was not appropriate; instead, the cancer potencies estimated by the Joint FAO/WHO Expert Committee on Food Additives in 2016 were used. For AFM1, a potency factor of 0.1 relative to AFB1 was used. For AFG1, AFB2 and AFG2, the in vivo data are not sufficient to derive potency factors and equal potency to AFB1 was assumed as in previous assessments. MOE values for AFB1 exposure ranged from 5,000 to 29 and for AFM1 from 100,000 to 508. The calculated MOEs are below 10,000 for AFB1 and also for AFM1 where some surveys, particularly for the younger age groups, have an MOE below 10,000. This raises a health concern. The estimated cancer risks in humans following exposure to AFB1 and AFM1 are in-line with the conclusion drawn from the MOEs. The conclusions also apply to the combined exposure to all five aflatoxins.
Collapse
|
15
|
Benkerroum N. Aflatoxins: Producing-Molds, Structure, Health Issues and Incidence in Southeast Asian and Sub-Saharan African Countries. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:E1215. [PMID: 32070028 PMCID: PMC7068566 DOI: 10.3390/ijerph17041215] [Citation(s) in RCA: 90] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 02/04/2020] [Accepted: 02/08/2020] [Indexed: 12/14/2022]
Abstract
This review aims to update the main aspects of aflatoxin production, occurrence and incidence in selected countries, and associated aflatoxicosis outbreaks. Means to reduce aflatoxin incidence in crops were also presented, with an emphasis on the environmentally-friendly technology using atoxigenic strains of Aspergillus flavus. Aflatoxins are unavoidable widespread natural contaminants of foods and feeds with serious impacts on health, agricultural and livestock productivity, and food safety. They are secondary metabolites produced by Aspergillus species distributed on three main sections of the genus (section Flavi, section Ochraceorosei, and section Nidulantes). Poor economic status of a country exacerbates the risk and the extent of crop contamination due to faulty storage conditions that are usually suitable for mold growth and mycotoxin production: temperature of 22 to 29 °C and water activity of 0.90 to 0.99. This situation paralleled the prevalence of high liver cancer and the occasional acute aflatoxicosis episodes that have been associated with these regions. Risk assessment studies revealed that Southeast Asian (SEA) and Sub-Saharan African (SSA) countries remain at high risk and that, apart from the regulatory standards revision to be more restrictive, other actions to prevent or decontaminate crops are to be taken for adequate public health protection. Indeed, a review of publications on the incidence of aflatoxins in selected foods and feeds from countries whose crops are classically known for their highest contamination with aflatoxins, reveals that despite the intensive efforts made to reduce such an incidence, there has been no clear tendency, with the possible exception of South Africa, towards sustained improvements. Nonetheless, a global risk assessment of the new situation regarding crop contamination with aflatoxins by international organizations with the required expertise is suggested to appraise where we stand presently.
Collapse
Affiliation(s)
- Noreddine Benkerroum
- Department of Food Science and Agricultural Chemistry, MacDonald Campus, McGill University, 21111 Lakeshore, Ste Anne de Bellevue, Quebec, H9X 3V9, Canada
| |
Collapse
|
16
|
Benkerroum N. Chronic and Acute Toxicities of Aflatoxins: Mechanisms of Action. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:E423. [PMID: 31936320 PMCID: PMC7013914 DOI: 10.3390/ijerph17020423] [Citation(s) in RCA: 167] [Impact Index Per Article: 41.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 12/23/2019] [Accepted: 12/29/2019] [Indexed: 01/01/2023]
Abstract
There are presently more than 18 known aflatoxins most of which have been insufficiently studied for their incidence, health-risk, and mechanisms of toxicity to allow effective intervention and control means that would significantly and sustainably reduce their incidence and adverse effects on health and economy. Among these, aflatoxin B1 (AFB1) has been by far the most studied; yet, many aspects of the range and mechanisms of the diseases it causes remain to be elucidated. Its mutagenicity, tumorigenicity, and carcinogenicity-which are the best known-still suffer from limitations regarding the relative contribution of the oxidative stress and the reactive epoxide derivative (Aflatoxin-exo 8,9-epoxide) in the induction of the diseases, as well as its metabolic and synthesis pathways. Additionally, despite the well-established additive effects for carcinogenicity between AFB1 and other risk factors, e.g., hepatitis viruses B and C, and the hepatotoxic algal microcystins, the mechanisms of this synergy remain unclear. This study reviews the most recent advances in the field of the mechanisms of toxicity of aflatoxins and the adverse health effects that they cause in humans and animals.
Collapse
Affiliation(s)
- Noreddine Benkerroum
- Department of Food Science and Agricultural Chemistry MacDonald Campus, McGill University, 21111 Lakeshore, Ste Anne de Bellevue, QC H9X 3V9, Canada
| |
Collapse
|
17
|
Klapacz J, Gollapudi BB. Considerations for the Use of Mutation as a Regulatory Endpoint in Risk Assessment. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2020; 61:84-93. [PMID: 31301246 DOI: 10.1002/em.22318] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 07/08/2019] [Accepted: 07/10/2019] [Indexed: 06/10/2023]
Abstract
Assessment of a chemical's potential to cause permanent changes in the genetic code has been a common practice in the industry and regulatory settings for decades. Furthermore, the genetic toxicity battery of tests has typically been employed during the earliest stages of the research and development programs of new product development. A positive outcome from such battery has a major impact on the chemical's utility, industrial hygiene, product stewardship practices, and product life cycle analysis, among many other decisions that need to be taken by the industry, even before the registration of a chemical is undertaken. Under the prevailing regulatory paradigm, the dichotomous (yes/no) evaluation of the chemical's genotoxic potential leads to a conservative, linear no-threshold (LNT) risk assessment, unless compelling and undeniable data to the contrary can be provided to satisfy regulators, typically in a number of different global jurisdictions. With the current advent of predictive methods, new testing paradigms, mode-of-action/adverse outcome pathways, and quantitative risk assessment approaches, various stakeholders are starting to employ these state-of-the-science methodologies to further the conversation on decision making and advance the regulatory paradigm beyond the dominant LNT status quo. This commentary describes these novel methodologies, relevant biological responses, and how these can affect internal and regulatory risk assessment approaches. Environ. Mol. Mutagen. 61:84-93, 2020. © 2019 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Joanna Klapacz
- Toxicology and Environmental Research and Consulting, The Dow Chemical Company, Midland, Michigan
| | | |
Collapse
|
18
|
Taguchi K, Kensler TW. Nrf2 in liver toxicology. Arch Pharm Res 2019; 43:337-349. [PMID: 31782059 DOI: 10.1007/s12272-019-01192-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Accepted: 11/19/2019] [Indexed: 12/14/2022]
Abstract
Liver plays essential roles in the metabolism of many endogenous chemicals and exogenous toxicants. Mechanistic studies in liver have been at the forefront of efforts to probe the roles of bioactivation and detoxication of environmental toxins and toxicants in hepatotoxicity. Moreover, idiosyncratic hepatoxicity remains a key barrier in the clinical development of drugs. The now vast Nrf2 field emerged in part from biochemical and molecular studies on chemical inducers of hepatic detoxication enzymes and subsequent characterization of the modulation of drug/toxicant induced hepatotoxicities in mice through disruption of either Nrf2 or Keap1 genes. In general, loss of Nrf2 increases the sensitivity to such toxic chemicals, highlighting a central role of this transcription factor and its downstream target genes as a modifier to chemical stress. In this review, we summarize the impact of Nrf2 on the toxicology of multiple hepatotoxicants, and discuss efforts to utilize the Nrf2 response in predictive toxicology.
Collapse
Affiliation(s)
- Keiko Taguchi
- Department of Medical Biochemistry, Graduate School of Medicine, Tohoku University, 2-1 Seiryo-machi, Aoba, Sendai, 980-8575, Japan.
| | - Thomas W Kensler
- Fred Hutchinson Cancer Research Center, 1100 Fairview Ave. N, Seattle, WA, 98109, USA
| |
Collapse
|
19
|
Benkerroum N. Retrospective and Prospective Look at Aflatoxin Research and Development from a Practical Standpoint. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:E3633. [PMID: 31569703 PMCID: PMC6801849 DOI: 10.3390/ijerph16193633] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/17/2019] [Revised: 09/24/2019] [Accepted: 09/26/2019] [Indexed: 12/19/2022]
Abstract
Among the array of structurally and toxicologically diverse mycotoxins, aflatoxins have attracted the most interest of scientific research due to their high toxicity and incidence in foods and feeds. Despite the undeniable progress made in various aspects related to aflatoxins, the ultimate goal consisting of reducing the associated public health risks worldwide is far from being reached due to multiplicity of social, political, economic, geographic, climatic, and development factors. However, a reasonable degree of health protection is attained in industrialized countries owing to their scientific, administrative, and financial capacities allowing them to use high-tech agricultural management systems. Less fortunate situations exist in equatorial and sub-equatorial developing countries mainly practicing traditional agriculture managed by smallholders for subsistence, and where the climate is suitable for mould growth and aflatoxin production. This situation worsens due to climatic change producing conditions increasingly suitable for aflatoxigenic mould growth and toxin production. Accordingly, it is difficult to harmonize the regulatory standards of aflatoxins worldwide, which prevents agri-foods of developing countries from accessing the markets of industrialized countries. To tackle the multi-faceted aflatoxin problem, actions should be taken collectively by the international community involving scientific research, technological and social development, environment protection, awareness promotion, etc. International cooperation should foster technology transfer and exchange of pertinent technical information. This review presents the main historical discoveries leading to our present knowledge on aflatoxins and the challenges that should be addressed presently and in the future at various levels to ensure higher health protection for everybody. In short, it aims to elucidate where we come from and where we should go in terms of aflatoxin research/development.
Collapse
Affiliation(s)
- Noreddine Benkerroum
- Department of Food Science and Agricultural Chemistry, Macdonald-Stewart Building, McGill University, Macdonald Campus, 21,111 Lakeshore Road, Sainte-Anne-de-Bellevue, QC H9X 3V9, Canada.
| |
Collapse
|
20
|
Livingstone MC, Johnson NM, Roebuck BD, Kensler TW, Groopman JD. Serum miR-182 is a predictive biomarker for dichotomization of risk of hepatocellular carcinoma in rats. Mol Carcinog 2019; 58:2017-2025. [PMID: 31373075 DOI: 10.1002/mc.23093] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2019] [Revised: 07/13/2019] [Accepted: 07/23/2019] [Indexed: 12/11/2022]
Abstract
Exploration of animal models leads to discoveries that can reveal candidate biomarkers for translation to human populations. Herein, a model of hepatocarcinogenesis and protection was used in which rats treated with aflatoxin (AFB1 ) daily for 28 days (200 µg/kg BW) developed tumors compared with rats completely protected from tumors by concurrent administration of the chemoprotective agent, 1-[2-cyano-3-,12-dioxooleana-1,9(11)-dien-28-oyl]imidazole (CDDO-Im). Differential expression of miRNAs in tumors (AFB1 ) and nontumor (AFB1 + CDDO-Im) bearing livers and their levels in sera over the life-course of the animals was determined. miRNA transcriptome analysis identified 17 miRNAs significantly upregulated at greater than five-fold in the tumors. The ten most dysregulated miRNAs judged by fold-change and biological significance were selected for further study, including liver-specific miR-122-5p. Validation of sequencing results by real-time PCR confirmed the upregulation of the majority of these miRNAs in tumors, including miR-182, as well as miR-224-5p as the most dysregulated of these miRNAs (over 400-fold). The longitudinal analysis of levels of miR-182 in sera demonstrated significant and persistent increases (5.13-fold; 95% CI: 4.59-5.70). The increase in miR-182 was detected months before any clinical symptoms were present in the animals. By the terminal time point of the study, in addition to elevated levels of serum miR-182, serum miR-122-5p was also found to be increased (>1.5-fold) in animals that developed hepatocarcinomas. Thus, using the data from an unbiased discovery approach of the tissue findings, serum miR-182 was found to track across the complex, multistage process of hepatocarcinogenesis opening an opportunity for translation to human populations.
Collapse
Affiliation(s)
- Merricka C Livingstone
- Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Natalie M Johnson
- Department of Environmental and Occupational Health, Texas A&M School of Public Health, College Station, Texas
| | - Bill D Roebuck
- Department of Pharmacology and Toxicology, Giesel School of Medicine at Dartmouth, Hanover, New Hampshire
| | - Thomas W Kensler
- Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.,Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington
| | - John D Groopman
- Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| |
Collapse
|
21
|
Bogen KT. Inflammation as a Cancer Co-Initiator: New Mechanistic Model Predicts Low/Negligible Risk at Noninflammatory Carcinogen Doses. Dose Response 2019; 17:1559325819847834. [PMID: 31205456 PMCID: PMC6537503 DOI: 10.1177/1559325819847834] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 04/07/2019] [Accepted: 04/09/2019] [Indexed: 01/10/2023] Open
Abstract
Linear-no-threshold (LNT) risk extrapolation has long been applied to estimate risks posed by low-level environmental carcinogen exposures, based on the 60-year-old multistage somatic mutation/clonal expansion (MSM) cancer theory. Recent evidence supports an alternative theory: Malignant tumors arise most efficiently from a stem cell that incurs requisite mutations and also is activated by inflammation to an epigenetically mediated and maintained state of adaptive hyperplasia (AH). This new inflammation-MSM (ISM) theory posits that inflammation-activated stem cells normally restricted to sites of injury-induced inflammation and tissue repair become uniquely susceptible to efficient carcinogenesis if normal post-inflammation AH termination is blocked by mutation. This theory posits that inflammation generally thus co-initiates cancer and transiently amplifies activated stem cells, implying that MSM theory (eg, the 2-stage stochastic "Moolgavkar, Venzon, Knudson [MVK]" model) is incomplete. Because inflammation dose-response typically is not LNT, the ISM theory predicts this is also true for most (perhaps all) carcinogens. The ISM (but not the MVK) model is shown to be consistent with recent data showing ∼100% carcinoma incidence (but not DNA adducts) in livers of rats exposed to aflatoxin B1 and was eliminated when that dose was co-administered with a highly potent anti-inflammatory agent. Experimental approaches to test ISM theory more robustly are discussed.
Collapse
|
22
|
McCullough AK, Lloyd RS. Mechanisms underlying aflatoxin-associated mutagenesis - Implications in carcinogenesis. DNA Repair (Amst) 2019; 77:76-86. [PMID: 30897375 DOI: 10.1016/j.dnarep.2019.03.004] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 03/01/2019] [Accepted: 03/05/2019] [Indexed: 01/07/2023]
Abstract
Chronic dietary exposure to aflatoxin B1 (AFB1), concomitant with hepatitis B infection is associated with a significant increased risk for hepatocellular carcinomas (HCCs) in people living in Southeast Asia and sub-Saharan Africa. Human exposures to AFB1 occur through the consumption of foods that are contaminated with pervasive molds, including Aspergillus flavus. Even though dietary exposures to aflatoxins constitute the second largest global environmental risk factor for cancer development, there are still significant questions concerning the molecular mechanisms driving carcinogenesis and what factors may modulate an individual's risk for HCC. The objective of this review is to summarize key discoveries that established the association of chronic inflammation (most commonly associated with hepatitis B viral (HBV) infection) and environmental exposures to aflatoxin with increased HCC risk. Special emphasis will be given to recent investigations that have: 1) refined the aflatoxin-associated mutagenic signature, 2) expanded the DNA repair mechanisms that limit mutagenesis via adduct removal prior to replication-induced mutagenesis, 3) implicated a specific DNA polymerase in the error-prone bypass and resulting mutagenesis, and 4) identified human polymorphic variants that may modulate individual susceptibility to aflatoxin-induced cancers. Collectively, these investigations revealed that specific sequence contexts are differentially resistant against, or prone to, aflatoxin-induced mutagenesis and that these associations are remarkably similar between in vitro and in vivo analyses. These recent investigations also established DNA polymerase ζ as the major polymerase that confers the G to T transversion signature. Additionally, although the nucleotide excision repair (NER) pathway has been previously shown to repair aflatoxin-induced DNA adducts, recent murine data demonstrated that NEIL1-initiated base excision repair was significantly more important than NER relative to the removal of the highly mutagenic AFB1-Fapy-dG adducts. These data suggest that inactivating polymorphic variants of NEIL1 could be a potential driver of HCCs in aflatoxin-exposed populations.
Collapse
Affiliation(s)
- Amanda K McCullough
- Oregon Institute of Occupational Health Sciences, Oregon Health & Science University, Portland, OR 97239, United States; Department of Molecular and Medical Genetics, Oregon Health & Science University, Portland, OR 97239, United States
| | - R Stephen Lloyd
- Oregon Institute of Occupational Health Sciences, Oregon Health & Science University, Portland, OR 97239, United States; Department of Molecular and Medical Genetics, Oregon Health & Science University, Portland, OR 97239, United States; Department of Physiology and Pharmacology, Oregon Health & Science University, Portland, OR 97239, United States.
| |
Collapse
|
23
|
Aflatoxin B1 metabolism: Regulation by phase I and II metabolizing enzymes and chemoprotective agents. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2018; 778:79-89. [DOI: 10.1016/j.mrrev.2018.10.002] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2018] [Accepted: 10/26/2018] [Indexed: 01/13/2023]
|
24
|
Soni P, Ghufran MS, Kanade SR. Aflatoxin B 1 induced multiple epigenetic modulators in human epithelial cell lines. Toxicon 2018; 151:119-128. [PMID: 30006306 DOI: 10.1016/j.toxicon.2018.07.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 06/15/2018] [Accepted: 07/08/2018] [Indexed: 12/12/2022]
Abstract
The compulsive and insidious secondary metabolite aflatoxin B1, produced by the opportunistic fungi Aspergillus flavus, upholds a distinguished place in midst of the toxicants causing fatal hazards to humans. Aflatoxins alter the function of host cells by inducing multiple effects through genetic and non-genetic pathways. Epigenetic mechanisms drag major attention towards finding novel and new mechanisms involved in this process. Our present work intends to study the functional expression profile of multiple epigenetic regulators. AFB1 modulates multiple epigenetic regulators like DNA methyltransferases (DMNTs), histones modifying enzymes and polycomb proteins. AFB1 upregulates the expression of DNMTs at gene and protein level in a dose dependent manner. It reduced the histone acetyl transferase (HAT) activity significantly with a remarkable increase in histone deacetylase (HDAC) activity along with an induction in expression of HDACs gene and protein in a dose dependent manner. The gene and protein expression of polycomb repressor proteins B cell specific moloney murine leukemia virus integration site 1 (BMI-1) and enhancer of zeste homolog 2 (EZH2) was significantly over expressed with enhanced trimethylation of H3K27 and ubiquitination of H2AK119. In summary, our results show impact of aflatoxin B1 on multiple epigenetic modulations known to be pivotal in oncogenic processes.
Collapse
Affiliation(s)
- Priyanka Soni
- Department of Biochemistry and Molecular Biology, School of Biological Sciences, Central University of Kerala, Kasargod 671314, Kerala, India
| | - Md Sajid Ghufran
- Department of Biochemistry and Molecular Biology, School of Biological Sciences, Central University of Kerala, Kasargod 671314, Kerala, India
| | - Santosh R Kanade
- Department of Biochemistry and Molecular Biology, School of Biological Sciences, Central University of Kerala, Kasargod 671314, Kerala, India.
| |
Collapse
|
25
|
Ghufran MS, Soni P, Kanade SR. Aflatoxin-induced upregulation of protein arginine methyltransferase 5 is mediated by protein kinase C and extracellular signal-regulated kinase. Cell Biol Toxicol 2018; 35:67-80. [DOI: 10.1007/s10565-018-9439-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 06/27/2018] [Indexed: 12/24/2022]
|
26
|
Yamamoto M, Kensler TW, Motohashi H. The KEAP1-NRF2 System: a Thiol-Based Sensor-Effector Apparatus for Maintaining Redox Homeostasis. Physiol Rev 2018; 98:1169-1203. [PMID: 29717933 PMCID: PMC9762786 DOI: 10.1152/physrev.00023.2017] [Citation(s) in RCA: 993] [Impact Index Per Article: 165.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The Kelch-like ECH-associated protein 1-NF-E2-related factor 2 (KEAP1-NRF2) system forms the major node of cellular and organismal defense against oxidative and electrophilic stresses of both exogenous and endogenous origins. KEAP1 acts as a cysteine thiol-rich sensor of redox insults, whereas NRF2 is a transcription factor that robustly transduces chemical signals to regulate a battery of cytoprotective genes. KEAP1 represses NRF2 activity under quiescent conditions, whereas NRF2 is liberated from KEAP1-mediated repression on exposure to stresses. The rapid inducibility of a response based on a derepression mechanism is an important feature of the KEAP1-NRF2 system. Recent studies have unveiled the complexities of the functional contributions of the KEAP1-NRF2 system and defined its broader involvement in biological processes, including cell proliferation and differentiation, as well as cytoprotection. In this review, we describe historical milestones in the initial characterization of the KEAP1-NRF2 system and provide a comprehensive overview of the molecular mechanisms governing the functions of KEAP1 and NRF2, as well as their roles in physiology and pathology. We also refer to the clinical significance of the KEAP1-NRF2 system as an important prophylactic and therapeutic target for various diseases, particularly aging-related disorders. We believe that controlled harnessing of the KEAP1-NRF2 system is a key to healthy aging and well-being in humans.
Collapse
|
27
|
Muhammad I, Wang H, Sun X, Wang X, Han M, Lu Z, Cheng P, Hussain MA, Zhang X. Dual Role of Dietary Curcumin Through Attenuating AFB 1-Induced Oxidative Stress and Liver Injury via Modulating Liver Phase-I and Phase-II Enzymes Involved in AFB 1 Bioactivation and Detoxification. Front Pharmacol 2018; 9:554. [PMID: 29887802 PMCID: PMC5981209 DOI: 10.3389/fphar.2018.00554] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 05/08/2018] [Indexed: 12/16/2022] Open
Abstract
It is well understood that liver cytochrome p450 enzymes are responsible for AFB1 bioactivation, while phase-II enzymes regulated by the transcription factor nuclear factor-erythroid-2-related factor 2 (Nrf2) are involved in detoxification of AFB1. In this study, we explored the potential of curcumin to prevent AFB1-induced liver injury by modulating liver phase-I and phase-II enzymes along with Nrf2 involved in AFB1 bioactivation and detoxification. Arbor Acres broiler were divided into four groups including control group (G1; fed only basal feed), curcumin alone-treated group (G2; 450 mg/kg feed), AFB1-fed group (G3; 5 mg/kg feed), and curcumin plus AFB1 group (G4; 5 mg AFB1+450 mg curcumin/kg feed). After 28 days, liver and blood samples were collected for different analyses. Histological and phenotypic results revealed that AFB1-induced liver injury was partially ameliorated by curcumin supplementation. Compared to AFB1 alone-treated group, serum biochemical parameters and liver antioxidant status showed that curcumin supplementation significantly prevented AFB1-induced liver injury. RT-PCR and western blot results revealed that curcumin inhibited CYP enzymes-mediated bioactivation of AFB1 at mRNA and protein level. Transcription factor Nrf2, its downstream genes such as GSTA3, and GSTM2 mRNA, and protein expression level significantly upregulated via dietary curcumin. In addition, GSTs enzyme activity was enhanced with dietary curcumin which plays a crucial role in AFB1-detoxification. Conclusively, the study provided a scientific basis for the use of curcumin in broiler's diet and contributed to explore the multi-target preventive actions of curcumin against AFB1-induced liver injury through the modulation of phase-I and phase-II enzymes, and its potent anti-oxidative effects.
Collapse
Affiliation(s)
- Ishfaq Muhammad
- Heilongjiang Key Laboratory for Animal Disease Control and Pharmaceutical Development, Faculty of Basic Veterinary Science, College of Veterinary Medicine, Northeast Agricultural University, Harbin, China
| | - He Wang
- Heilongjiang Key Laboratory for Animal Disease Control and Pharmaceutical Development, Faculty of Basic Veterinary Science, College of Veterinary Medicine, Northeast Agricultural University, Harbin, China
| | - Xiaoqi Sun
- Heilongjiang Key Laboratory for Animal Disease Control and Pharmaceutical Development, Faculty of Basic Veterinary Science, College of Veterinary Medicine, Northeast Agricultural University, Harbin, China
| | - Xinghe Wang
- Laboratory of Veterinary Pathology, Faculty of Basic Veterinary Science, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, China
| | - Meiyu Han
- Changchun Dirui Medical Company Ltd., Changchun, China
| | - Ziyin Lu
- College of Life Science Engineering, Shenyang Institute of Technology, Fushun, China
| | - Ping Cheng
- Heilongjiang Key Laboratory for Animal Disease Control and Pharmaceutical Development, Faculty of Basic Veterinary Science, College of Veterinary Medicine, Northeast Agricultural University, Harbin, China
| | | | - Xiuying Zhang
- Heilongjiang Key Laboratory for Animal Disease Control and Pharmaceutical Development, Faculty of Basic Veterinary Science, College of Veterinary Medicine, Northeast Agricultural University, Harbin, China
| |
Collapse
|
28
|
Wible RS, Tran QT, Fathima S, Sutter CH, Kensler TW, Sutter TR. Pharmacogenomics of Chemically Distinct Classes of Keap1-Nrf2 Activators Identify Common and Unique Gene, Protein, and Pathway Responses In Vivo. Mol Pharmacol 2018; 93:297-308. [PMID: 29367259 PMCID: PMC5832324 DOI: 10.1124/mol.117.110262] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Accepted: 01/19/2018] [Indexed: 12/11/2022] Open
Abstract
The Kelch-like erythroid-associated protein 1 (Keap1)-NF-E2-related factor 2 (Nrf2) signaling pathway is the subject of several clinical trials evaluating the effects of Nrf2 activation on the prevention of cancer and diabetes and the treatment of chronic kidney disease and multiple sclerosis. 3H-1,2-dithiole-3-thione (D3T) and 1-[2-cyano-3,12-dioxooleana-1,9(11)-dien-28-oyl]imidazole (CDDO-Im) are representative members of two distinct series of Nrf2 chemical activators. Previous reports have described activator-specific effects on Nrf2-dependent gene regulation and physiologic outcomes. Here we used a robust chemical genomics approach to characterize expression profiles between D3T and CDDO-Im in livers from wild-type and Nrf2-null mice. At equally efficacious doses in wild-type mice, 406 genes show common RNA responses to both treatments. These genes enriched the Nrf2-regulated pathways of antioxidant defense and xenobiotic metabolism. In addition, 197 and 745 genes were regulated uniquely in response to either D3T or CDDO-Im, respectively. Functional analysis of the D3T-regulated set showed a significant enrichment of Nrf2-regulated enzymes involved in cholesterol biosynthesis. This result was supported by Nrf2-dependent increases in lanosterol synthase and CYP51 protein expression. CDDO-Im had no effect on cholesterol biosynthesis regardless of the dose tested. However, unlike D3T, CDDO-Im resulted in Nrf2-dependent elevation of peroxisome proliferator α and Kruppel-like factor 13, as well as the coactivator peroxisome proliferator γ coactivator 1β, together indicating regulation of β-oxidation and lipid metabolic pathways. These findings provide novel insights into the pharmacodynamic action of these two activators of Keap1-Nrf2 signaling. Although both compounds modify Keap1 to affect canonical cytoprotective gene expression, additional unique sets of Nrf2-dependent genes were regulated by each agent with enrichment of selective metabolic pathways.
Collapse
Affiliation(s)
- Ryan S Wible
- Departments of Chemistry (R.S.W., T.R.S.) and Biological Sciences (C.H.S., T.R.S.,) and the W. Harry Feinstone Center for Genomic Research (R.S.W., S.F., T.R.S.), University of Memphis, Memphis, Tennessee; Department of Preventive Medicine, University of Tennessee Health Science Center, Memphis, Tennessee (Q.T.T.); Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland (T.W.K.); and Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania (T.W.K.)
| | - Quynh T Tran
- Departments of Chemistry (R.S.W., T.R.S.) and Biological Sciences (C.H.S., T.R.S.,) and the W. Harry Feinstone Center for Genomic Research (R.S.W., S.F., T.R.S.), University of Memphis, Memphis, Tennessee; Department of Preventive Medicine, University of Tennessee Health Science Center, Memphis, Tennessee (Q.T.T.); Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland (T.W.K.); and Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania (T.W.K.)
| | - Samreen Fathima
- Departments of Chemistry (R.S.W., T.R.S.) and Biological Sciences (C.H.S., T.R.S.,) and the W. Harry Feinstone Center for Genomic Research (R.S.W., S.F., T.R.S.), University of Memphis, Memphis, Tennessee; Department of Preventive Medicine, University of Tennessee Health Science Center, Memphis, Tennessee (Q.T.T.); Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland (T.W.K.); and Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania (T.W.K.)
| | - Carrie H Sutter
- Departments of Chemistry (R.S.W., T.R.S.) and Biological Sciences (C.H.S., T.R.S.,) and the W. Harry Feinstone Center for Genomic Research (R.S.W., S.F., T.R.S.), University of Memphis, Memphis, Tennessee; Department of Preventive Medicine, University of Tennessee Health Science Center, Memphis, Tennessee (Q.T.T.); Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland (T.W.K.); and Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania (T.W.K.)
| | - Thomas W Kensler
- Departments of Chemistry (R.S.W., T.R.S.) and Biological Sciences (C.H.S., T.R.S.,) and the W. Harry Feinstone Center for Genomic Research (R.S.W., S.F., T.R.S.), University of Memphis, Memphis, Tennessee; Department of Preventive Medicine, University of Tennessee Health Science Center, Memphis, Tennessee (Q.T.T.); Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland (T.W.K.); and Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania (T.W.K.)
| | - Thomas R Sutter
- Departments of Chemistry (R.S.W., T.R.S.) and Biological Sciences (C.H.S., T.R.S.,) and the W. Harry Feinstone Center for Genomic Research (R.S.W., S.F., T.R.S.), University of Memphis, Memphis, Tennessee; Department of Preventive Medicine, University of Tennessee Health Science Center, Memphis, Tennessee (Q.T.T.); Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland (T.W.K.); and Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania (T.W.K.)
| |
Collapse
|
29
|
Wang H, Muhammad I, Li W, Sun X, Cheng P, Zhang X. Sensitivity of Arbor Acres broilers and chemoprevention of aflatoxin B 1-induced liver injury by curcumin, a natural potent inducer of phase-II enzymes and Nrf2. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2018; 59:94-104. [PMID: 29550706 DOI: 10.1016/j.etap.2018.03.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 02/10/2018] [Accepted: 03/04/2018] [Indexed: 06/08/2023]
Abstract
In this study, we scrutinized the effects of curcumin and AFB1 supplemented diet alone or in combination on phase-ӀӀ enzymes. Histopathological examination showed that after 28 days, AFB1 (5.0 mg/kg diet) induced liver injury in broilers, but curcumin supplementation partially ameliorated liver injury in a dose-dependent manner. RT-PCR data revealed that AFB1 significantly (p < 0.01) down-regulated Nrf2 and its downstream genes mRNA expression level. Moreover, Western blot analysis showed that Nrf2, GSTM2, and GSTA3 protein expression level was markedly (p < 0.01) reduced in AFB1-fed group. However, curcumin supplementation ameliorated AFB1-induced liver injury via enhancing phase-ӀӀ enzymes expressions and activity. HPLC results showed that curcumin increased AFB1-GSH conjugation in-vitro in liver cytosol. Surprisingly, similar trends were noted in mRNA, protein expression level of Nrf2 and its downstream genes at day 35, one week after the withdrawal of AFB1 and curcumin from the diet, showing the preventive effects of curcumin.
Collapse
Affiliation(s)
- He Wang
- Heilongjiang Key Laboratory for Animal Disease Control and Pharmaceutical Development. Faculty of Basic Veterinary Science, College of Veterinary Medicine, Northeast Agricultural University, 600 Changjiang Road, Xiangfang District, Harbin, PR China
| | - Ishfaq Muhammad
- Heilongjiang Key Laboratory for Animal Disease Control and Pharmaceutical Development. Faculty of Basic Veterinary Science, College of Veterinary Medicine, Northeast Agricultural University, 600 Changjiang Road, Xiangfang District, Harbin, PR China
| | - Wei Li
- Heilongjiang Key Laboratory for Animal Disease Control and Pharmaceutical Development. Faculty of Basic Veterinary Science, College of Veterinary Medicine, Northeast Agricultural University, 600 Changjiang Road, Xiangfang District, Harbin, PR China
| | - Xiaoqi Sun
- Heilongjiang Key Laboratory for Animal Disease Control and Pharmaceutical Development. Faculty of Basic Veterinary Science, College of Veterinary Medicine, Northeast Agricultural University, 600 Changjiang Road, Xiangfang District, Harbin, PR China
| | - Ping Cheng
- Heilongjiang Key Laboratory for Animal Disease Control and Pharmaceutical Development. Faculty of Basic Veterinary Science, College of Veterinary Medicine, Northeast Agricultural University, 600 Changjiang Road, Xiangfang District, Harbin, PR China
| | - Xiuying Zhang
- Heilongjiang Key Laboratory for Animal Disease Control and Pharmaceutical Development. Faculty of Basic Veterinary Science, College of Veterinary Medicine, Northeast Agricultural University, 600 Changjiang Road, Xiangfang District, Harbin, PR China.
| |
Collapse
|
30
|
Cuadrado A, Manda G, Hassan A, Alcaraz MJ, Barbas C, Daiber A, Ghezzi P, León R, López MG, Oliva B, Pajares M, Rojo AI, Robledinos-Antón N, Valverde AM, Guney E, Schmidt HHHW. Transcription Factor NRF2 as a Therapeutic Target for Chronic Diseases: A Systems Medicine Approach. Pharmacol Rev 2018; 70:348-383. [DOI: 10.1124/pr.117.014753] [Citation(s) in RCA: 329] [Impact Index Per Article: 54.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
|
31
|
Moore MM, Schoeny RS, Becker RA, White K, Pottenger LH. Development of an adverse outcome pathway for chemically induced hepatocellular carcinoma: case study of AFB1, a human carcinogen with a mutagenic mode of action. Crit Rev Toxicol 2018; 48:312-337. [PMID: 29431554 DOI: 10.1080/10408444.2017.1423462] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Adverse outcome pathways (AOPs) are frameworks starting with a molecular initiating event (MIE), followed by key events (KEs) linked by KE relationships (KERs), ultimately resulting in a specific adverse outcome. Relevant data for the pathway and each KE/KER are evaluated to assess biological plausibility, weight-of-evidence, and confidence. We aimed to describe an AOP relevant to chemicals directly inducing mutation in cancer critical gene(s), via the formation of chemical-specific pro-mutagenic DNA adduct(s), as an early critical step in tumor etiology. Such chemicals have mutagenic modes-of-action (MOA) for tumor induction. To assist with developing this AOP, Aflatoxin B1 (AFB1) was selected as a case study because it has a rich database and is considered to have a mutagenic MOA. AFB1 information was used to define specific KEs, KERs, and to inform development of a generic AOP for mutagen-induced hepatocellular carcinoma (HCC). In assessing the AFB1 information, it became clear that existing data are, in fact, not optimal and for some KEs/KERs, the definitive data are not available. In particular, while there is substantial information that AFB1 can induce mutations (based on a number of mutation assays), the definitive evidence - the ability to induce mutation in the cancer critical gene(s) in the tumor target tissue - is not available. Thus, it is necessary to consider the patterns of results in the weight-of-evidence for KEs and KERs. It was important to determine whether there was sufficient evidence that AFB1 can induce the necessary critical mutations early in the carcinogenic process, which was the case.
Collapse
Affiliation(s)
- Martha M Moore
- a Ramboll Environ US Corporation , Little Rock , AR , USA
| | | | | | | | | |
Collapse
|
32
|
Merrick BA, Chang JS, Phadke DP, Bostrom MA, Shah RR, Wang X, Gordon O, Wright GM. HAfTs are novel lncRNA transcripts from aflatoxin exposure. PLoS One 2018; 13:e0190992. [PMID: 29351317 PMCID: PMC5774710 DOI: 10.1371/journal.pone.0190992] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 12/22/2017] [Indexed: 12/28/2022] Open
Abstract
The transcriptome can reveal insights into precancer biology. We recently conducted RNA-Seq analysis on liver RNA from male rats exposed to the carcinogen, aflatoxin B1 (AFB1), for 90 days prior to liver tumor onset. Among >1,000 differentially expressed transcripts, several novel, unannotated Cufflinks-assembled transcripts, or HAfTs (Hepatic Aflatoxin Transcripts) were found. We hypothesized PCR-cloning and RACE (rapid amplification of cDNA ends) could further HAfT identification. Sanger data was obtained for 6 transcripts by PCR and 16 transcripts by 5’- and 3’-RACE. BLAST alignments showed, with two exceptions, HAfT transcripts were lncRNAs, >200nt without apparent long open reading frames. Six rat HAfT transcripts were classified as ‘novel’ without RefSeq annotation. Sequence alignment and genomic synteny showed each rat lncRNA had a homologous locus in the mouse genome and over half had homologous loci in the human genome, including at least two loci (and possibly three others) that were previously unannotated. While HAfT functions are not yet clear, coregulatory roles may be possible from their adjacent orientation to known coding genes with altered expression that include 8 HAfT-gene pairs. For example, a unique rat HAfT, homologous to Pvt1, was adjacent to known genes controlling cell proliferation. Additionally, PCR and RACE Sanger sequencing showed many alternative splice variants and refinements of exon sequences compared to Cufflinks assembled transcripts and gene prediction algorithms. Presence of multiple splice variants and short tandem repeats found in some HAfTs may be consequential for secondary structure, transcriptional regulation, and function. In summary, we report novel, differentially expressed lncRNAs after exposure to the genotoxicant, AFB1, prior to neoplastic lesions. Complete cloning and sequencing of such transcripts could pave the way for a new set of sensitive and early prediction markers for chemical hepatocarcinogens.
Collapse
Affiliation(s)
- B. Alex Merrick
- Biomolecular Screening Branch, Division National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, United States of America
- * E-mail:
| | - Justin S. Chang
- Biomolecular Screening Branch, Division National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, United States of America
| | - Dhiral P. Phadke
- Sciome, LLC, Research Triangle Park, North Carolina, United States of America
| | - Meredith A. Bostrom
- Genomics Laboratory, David H. Murdock Research Institute, Kannapolis, North Carolina, United State of America
| | - Ruchir R. Shah
- Sciome, LLC, Research Triangle Park, North Carolina, United States of America
| | - Xinguo Wang
- Genomics Laboratory, David H. Murdock Research Institute, Kannapolis, North Carolina, United State of America
| | - Oksana Gordon
- Genomics Laboratory, David H. Murdock Research Institute, Kannapolis, North Carolina, United State of America
| | - Garron M. Wright
- Genomics Laboratory, David H. Murdock Research Institute, Kannapolis, North Carolina, United State of America
| |
Collapse
|
33
|
Limaye A, Yu RC, Chou CC, Liu JR, Cheng KC. Protective and Detoxifying Effects Conferred by Dietary Selenium and Curcumin against AFB1-Mediated Toxicity in Livestock: A Review. Toxins (Basel) 2018; 10:E25. [PMID: 29301315 PMCID: PMC5793112 DOI: 10.3390/toxins10010025] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Revised: 12/28/2017] [Accepted: 12/28/2017] [Indexed: 12/21/2022] Open
Abstract
Aflatoxin B1 (AFB1), among other aflatoxins of the aflatoxin family, is the most carcinogenic and hazardous mycotoxin to animals and human beings with very high potency leading to aflatoxicosis. Selenium is an essential trace mineral possessing powerful antioxidant functions. Selenium is widely reported as an effective antioxidant against aflatoxicosis. By preventing oxidative liver damage, suppressing pro-apoptotic proteins and improving immune status in AFB1 affected animals; selenium confers specific protection against AFB1 toxicity. Meticulous supplementation of animal feed by elemental selenium in the organic and inorganic forms has proven to be effective to ameliorate AFB1 toxicity. Curcumin is another dietary agent of importance in tackling aflatoxicosis. Curcumin is one of the major active ingredients in the tubers of a spice Curcuma longa L., a widely reported antioxidant, anticarcinogenic agent with reported protective potential against aflatoxin-mediated liver damage. Curcumin restricts the aflatoxigenic potential of Aspergillusflavus. Curcumin inhibits cytochrome P450 isoenzymes, particularly CYP2A6 isoform; thereby reducing the formation of AFB1-8, 9-epoxide and other toxic metabolites causing aflatoxicosis. In this review, we have briefly reviewed important aflatoxicosis symptoms among animals. With the main focus on curcumin and selenium, we have reviewed their underlying protective mechanisms in different animals along with their extraction and production methods for feed applications.
Collapse
Affiliation(s)
- Aniket Limaye
- Institute of Biotechnology, National Taiwan University, Taipei 10617, Taiwan.
| | - Roch-Chui Yu
- Graduate Institute of Food Science Technology, National Taiwan University, Taipei 10617, Taiwan.
| | - Cheng-Chun Chou
- Department of Medical Research, China Medical University Hospital, China Medical University, Taichung 404, Taiwan.
| | - Je-Ruei Liu
- Institute of Biotechnology, National Taiwan University, Taipei 10617, Taiwan.
| | - Kuan-Chen Cheng
- Institute of Biotechnology, National Taiwan University, Taipei 10617, Taiwan.
- Graduate Institute of Food Science Technology, National Taiwan University, Taipei 10617, Taiwan.
- Department of Medical Research, China Medical University Hospital, China Medical University, Taichung 404, Taiwan.
| |
Collapse
|
34
|
Sklirou A, Papanagnou ED, Fokialakis N, Trougakos IP. Cancer chemoprevention via activation of proteostatic modules. Cancer Lett 2018; 413:110-121. [DOI: 10.1016/j.canlet.2017.10.034] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 10/16/2017] [Accepted: 10/20/2017] [Indexed: 12/11/2022]
|
35
|
Crawford DR, Ilic Z, Guest I, Milne GL, Hayes JD, Sell S. Characterization of liver injury, oval cell proliferation and cholangiocarcinogenesis in glutathione S-transferase A3 knockout mice. Carcinogenesis 2017; 38:717-727. [PMID: 28535182 DOI: 10.1093/carcin/bgx048] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
We recently generated glutathione S-transferase (GST) A3 knockout (KO) mice as a novel model to study the risk factors for liver cancer. GSTA3 KO mice are sensitive to the acute cytotoxic and genotoxic effects of aflatoxin B1 (AFB1), confirming the crucial role of GSTA3 in resistance to AFB1. We now report histopathological changes, tumor formation, biochemical changes and gender response following AFB1 treatment as well as the contribution of oxidative stress. Using a protocol of weekly 0.5 mg AFB1/kg administration, we observed extensive oval (liver stem) cell (OC) proliferation within 1-3 weeks followed by microvesicular lipidosis, megahepatocytes, nuclear inclusions, cholangiomas and small nodules. Male and female GSTA3 KO mice treated with 12 and 24 weekly AFB1 injections followed by a rest period of 12 and 6 months, respectively, all had grossly distorted livers with macro- and microscopic cysts, hepatocellular nodules, cholangiomas and cholangiocarcinomas and OC proliferation. We postulate that the prolonged AFB1 treatment leads to inhibition of hepatocyte proliferation, which is compensated by OC proliferation and eventually formation of cholangiocarcinoma (CCA). At low-dose AFB1, male KO mice showed less extensive acute liver injury, OC proliferation and AFB1-DNA adducts than female KO mice. There were no significant compensatory changes in KO mice GST subunits, GST enzymatic activity, epoxide hydrolase, or CYP1A2 and CYP3A11 levels. Finally, there was a modest increase in F2-isoprostane and isofuran in KO mice that confirmed putative GSTA3 hydroperoxidase activity in vivo for the first time.
Collapse
Affiliation(s)
- Dana R Crawford
- Albany Medical Center, Department of Immunology and Microbial Disease, 43 New Scotland Avenue, Albany, NY 12208, USA
| | - Zoran Ilic
- Wadsworth Center, New York State Department of Health, Albany, NY 12201, USA
| | - Ian Guest
- Wadsworth Center, New York State Department of Health, Albany, NY 12201, USA
| | - Ginger L Milne
- Vanderbilt University School of Medicine, Department of Medicine and Pharmacology, Nashville, TN 37323, USA
| | - John D Hayes
- Division of Cancer Research, Medical Research Institute, University of Dundee, Ninewells Hospital and Medical School, Dundee, DD1 9SY, UK
| | - Stewart Sell
- Wadsworth Center, New York State Department of Health, Albany, NY 12201, USA
| |
Collapse
|
36
|
Xiang X, Qin HG, You XM, Wang YY, Qi LN, Ma L, Xiang BD, Zhong JH, Li LQ. Expression of P62 in hepatocellular carcinoma involving hepatitis B virus infection and aflatoxin B1 exposure. Cancer Med 2017; 6:2357-2369. [PMID: 28941211 PMCID: PMC5633547 DOI: 10.1002/cam4.1176] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 07/23/2017] [Accepted: 08/04/2017] [Indexed: 01/27/2023] Open
Abstract
This study aims to clarify the relationship and mechanism between expression of autophagy‐related protein P62 and prognosis of patients with hepatocellular carcinoma (HCC) involving chronic hepatitis B virus (HBV) infection and aflatoxin B1 (AFB1) exposure. HCC patients who underwent resection were divided into three groups: HBV(+)/AFB1(+) (n = 26), HBV(+)/AFB1(−) (n = 68), and HBV(−)/AFB1(−) (n = 14). The groups were compared in terms of mRNA and protein levels of P62, disease‐free survival (DFS), and overall survival (OS) and the expression of NRF2, Nqo1, and AKR7A3 in P62 high‐expression and low‐expression group. HBV(+)/AFB1(+) group has lower DFS and OS, and higher P62 expression than in the other two groups. P62 expression generally correlated with elevated NRF2 and Nqo1 expression, and reduced AKR7A3 expression. Patients expressing high levels of P62 showed significantly lower DFS and OS rates than patients expressing low levels. HCC involving HBV infection and AFB1 exposure is associated with relatively high risk of tumor recurrence, and this poor prognosis may relate to high P62 expression. High P62 expression activates the NRF2 pathway, promotes tumor recurrence. The downregulation of AKR7A3 also reduced liver detoxification of aflatoxin B1.
Collapse
Affiliation(s)
- Xiao Xiang
- Department of Hepatobiliary Surgery, Affiliated Tumor Hospital of Guangxi Medical University, Guangxi Cancer Institute, Hospital Oncology School, Guangxi Cancer Center, Nanning, 530021, China
| | - Hong-Gui Qin
- Department of Hepatobiliary Surgery, Affiliated Tumor Hospital of Guangxi Medical University, Guangxi Cancer Institute, Hospital Oncology School, Guangxi Cancer Center, Nanning, 530021, China
| | - Xue-Mei You
- Department of Hepatobiliary Surgery, Affiliated Tumor Hospital of Guangxi Medical University, Guangxi Cancer Institute, Hospital Oncology School, Guangxi Cancer Center, Nanning, 530021, China.,Guangxi Liver Cancer Diagnosis and Treatment Engineering and Technology Research Center, Nanning, 530021, China
| | - Yan-Yan Wang
- Department of Hepatobiliary Surgery, Affiliated Tumor Hospital of Guangxi Medical University, Guangxi Cancer Institute, Hospital Oncology School, Guangxi Cancer Center, Nanning, 530021, China
| | - Lu-Nan Qi
- Department of Hepatobiliary Surgery, Affiliated Tumor Hospital of Guangxi Medical University, Guangxi Cancer Institute, Hospital Oncology School, Guangxi Cancer Center, Nanning, 530021, China.,Guangxi Liver Cancer Diagnosis and Treatment Engineering and Technology Research Center, Nanning, 530021, China
| | - Liang Ma
- Department of Hepatobiliary Surgery, Affiliated Tumor Hospital of Guangxi Medical University, Guangxi Cancer Institute, Hospital Oncology School, Guangxi Cancer Center, Nanning, 530021, China.,Guangxi Liver Cancer Diagnosis and Treatment Engineering and Technology Research Center, Nanning, 530021, China
| | - Bang-De Xiang
- Department of Hepatobiliary Surgery, Affiliated Tumor Hospital of Guangxi Medical University, Guangxi Cancer Institute, Hospital Oncology School, Guangxi Cancer Center, Nanning, 530021, China.,Guangxi Liver Cancer Diagnosis and Treatment Engineering and Technology Research Center, Nanning, 530021, China
| | - Jian-Hong Zhong
- Department of Hepatobiliary Surgery, Affiliated Tumor Hospital of Guangxi Medical University, Guangxi Cancer Institute, Hospital Oncology School, Guangxi Cancer Center, Nanning, 530021, China.,Guangxi Liver Cancer Diagnosis and Treatment Engineering and Technology Research Center, Nanning, 530021, China
| | - Le-Qun Li
- Department of Hepatobiliary Surgery, Affiliated Tumor Hospital of Guangxi Medical University, Guangxi Cancer Institute, Hospital Oncology School, Guangxi Cancer Center, Nanning, 530021, China.,Guangxi Liver Cancer Diagnosis and Treatment Engineering and Technology Research Center, Nanning, 530021, China
| |
Collapse
|
37
|
Livingstone MC, Johnson NM, Roebuck BD, Kensler TW, Groopman JD. Profound changes in miRNA expression during cancer initiation by aflatoxin B 1 and their abrogation by the chemopreventive triterpenoid CDDO-Im. Mol Carcinog 2017; 56:2382-2390. [PMID: 28218475 DOI: 10.1002/mc.22635] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 02/01/2017] [Accepted: 02/16/2017] [Indexed: 12/17/2022]
Abstract
Aflatoxin B1 (AFB1 ) is a potent human and animal hepatocarcinogen. To investigate the effects of aflatoxin on miRNA expression during the initiation phase of carcinogenesis, next-generation sequencing was used to analyze liver tissues from F344 rats exposed to 200 μg/kg per day AFB1 for 4 week. A panel of miRNAs was identified that was upregulated with AFB1 treatment compared to controls: rno-miR-434-3p, rno-miR-411-5p, rno-miR-221-3p, rno-miR-127-3p, rno-miR-205, rno-miR-429, rno-miR-34a-5p, rno-miR-181c-3p, rno-miR-200b-3p, and rno-miR-541-5p. Analysis of rat livers exposed to AFB1 plus the chemopreventive triterpenoid CDDO-Im revealed a striking abrogation of this upregulation. These changes were validated by real-time PCR. We also explored the temporal variation in expression of the candidate miRNAs during the 4-week dosing period. Most of the candidate miRNAs were upregulated at week 1 and increased for the duration of AFB1 dosing over the 4-week period. Treatment with CDDO-Im ameliorated these effects at all time points. All candidate miRNAs were detectable in serum from aflatoxin treated animals; however, there was no significant difference in expression for 7 of the 11 miRNAs examined. Exposure to AFB1 upregulated miR-122-5p (fivefold), 34a-5p (13-fold), and 181c-3p (170-fold) compared with controls. The findings from this study give insight into epigenetic changes induced by aflatoxin taking place during the initial step of carcinogenesis.
Collapse
Affiliation(s)
| | | | - Bill D Roebuck
- Dartmouth College School of Medicine, Hanover, New Hampshire
| | - Thomas W Kensler
- Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.,University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - John D Groopman
- Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| |
Collapse
|
38
|
Taguchi K, Yamamoto M. The KEAP1-NRF2 System in Cancer. Front Oncol 2017; 7:85. [PMID: 28523248 PMCID: PMC5415577 DOI: 10.3389/fonc.2017.00085] [Citation(s) in RCA: 337] [Impact Index Per Article: 48.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 04/18/2017] [Indexed: 12/30/2022] Open
Abstract
Cancer cells first adapt to the microenvironment and then propagate. Mutations in tumor suppressor genes or oncogenes are frequently found in cancer cells. Comprehensive genomic analyses have identified somatic mutations and other alterations in the KEAP1 or NRF2 genes and in well-known tumor suppressor genes or oncogenes, such as TP53, CDKN2A, PTEN, and PIK3CA, in various types of cancer. Aberrant NRF2 activation in cancer cells occurs through somatic mutations in the KEAP1 or NRF2 gene as well as through other mechanisms that disrupt the binding of KEAP1 to NRF2. Unregulated NRF2 confers on cancer cells high-level resistance to anticancer drugs and reactive oxygen species (ROS) and directs cancer cells toward metabolic reprogramming. Therefore, NRF2 has been studied as a therapeutic target molecule in cancer. Two strategies have been used to target NRF2 via therapeutic drugs: inhibition of NRF2 and induction of NRF2. NRF2 inhibitors may be effective against NRF2-addicted cancer cells in which NRF2 is aberrantly activated. These inhibitors have not yet been established as NRF2-targeted anticancer drugs for the treatment of human cancers. Diagnosis of NRF2 activation could facilitate the use of NRF2 inhibitors for the treatment of patients with NRF2-addicted cancers. Conversely, NRF2 inducers have been used or are being developed for non-cancer diseases. In addition, NRF2 inducers may be useful for cancer chemotherapy in combination with conventional anticancer agents or even NRF2 inhibitors.
Collapse
Affiliation(s)
- Keiko Taguchi
- Department of Medical Biochemistry, Graduate School of Medicine, Tohoku University, Sendai, Japan
| | - Masayuki Yamamoto
- Department of Medical Biochemistry, Graduate School of Medicine, Tohoku University, Sendai, Japan
| |
Collapse
|
39
|
Abstract
Kelch-like ECH-associated protein 1 (Keap1), nuclear factor erythroid 2-like factor 2-related factor 2 (Nrf2), and the antioxidant response element (ARE) are interacting components of a master regulatory signaling pathway that coordinates redox homeostasis, cytoprotective responses, and shifts in stem cell state. This study reexamined detailed dose–response (DR) data reported for in vitro Nrf2-ARE activation in human hepatoblastoma HepG2 cell lines containing either a ARE-bla or ARE-luc reporter at 12 different concentrations of each of 15 chemicals. The normalized study data were combined among chemicals exhibiting a positive response, yielding n = 531 (179) DR data for 9 (7) chemicals using the ARE-bla (ARE-luc) assay. Three-parameter linear/kth-power regression fits obtained to each combined set of ARE-bla- or ARE-luc-assay response data provided good fits (R2 = .99 or .91, respectively, Pfit > .99) that each incorporate a highly significant negative initial linear slope (P = 4 × 10−5 or .00025) and an overall J-shaped DR pattern. Results from this reanalysis of high-resolution ARE response data support the hypothesis that nonlinear ARE-mediated adaptive cellular responses to oxidative stress are governed by an ultrasensitive molecular switch.
Collapse
|
40
|
Wible RS, Sutter TR. Soft Cysteine Signaling Network: The Functional Significance of Cysteine in Protein Function and the Soft Acids/Bases Thiol Chemistry That Facilitates Cysteine Modification. Chem Res Toxicol 2017; 30:729-762. [DOI: 10.1021/acs.chemrestox.6b00428] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Ryan S. Wible
- Department
of Chemistry, ‡Department of Biological Sciences, and §W. Harry Feinstone Center for Genomic
Research, University of Memphis, 3700 Walker Avenue, Memphis, Tennessee 38152-3370, United States
| | - Thomas R. Sutter
- Department
of Chemistry, ‡Department of Biological Sciences, and §W. Harry Feinstone Center for Genomic
Research, University of Memphis, 3700 Walker Avenue, Memphis, Tennessee 38152-3370, United States
| |
Collapse
|
41
|
Pollock BH, Elmore S, Romoser A, Tang L, Kang MS, Xue K, Rodriguez M, Dierschke NA, Hayes HG, Hansen HA, Guerra F, Wang JS, Phillips T. Intervention trial with calcium montmorillonite clay in a south Texas population exposed to aflatoxin. Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2016; 33:1346-54. [PMID: 27321368 DOI: 10.1080/19440049.2016.1198498] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
South Texas currently has the highest incidence of hepatocellular carcinoma (HCC) in the United States, a disease that disproportionately affects Latino populations in the region. Aflatoxin B1 (AFB1) is a potent liver carcinogen that has been shown to be present in a variety of foods in the United States, including corn and corn products. Importantly, it is a dietary risk factor contributing to a higher incidence of HCC in populations frequently consuming AFB1-contaminated diets. In a randomised double-blind placebo controlled trial, we evaluated the effects of a 3-month administration of ACCS100 (refined calcium montmorillonite clay) on serum AFB1-lysine adduct (AFB-Lys) level and serum biochemistry in 234 healthy men and women residing in Bexar and Medina counties, Texas. Participants recruited from 2012 to 2014 received either a placebo, 1.5 g or 3 g ACCS100 each day for 3 months, and no treatment during the fourth month. Adverse event rates were similar across treatment groups and no significant differences were observed for serum biochemistry and haematology parameters. Differences in levels of AFB-Lys at 1, 3 and 4 months were compared between placebo and active treatment groups. Although serum AFB-Lys levels were decreased by month 3 for both treatment groups, the low dose was the only treatment that was significant (p = 0.0005). In conclusion, the observed effect in the low-dose treatment group suggests that the use of ACCS100 may be a viable strategy to reduce dietary AFB1 bioavailability during aflatoxin outbreaks and potentially in populations chronically exposed to this carcinogen.
Collapse
Affiliation(s)
- Brad H Pollock
- a Department of Public Health Sciences , University of California , Davis , CA , USA.,b Department of Epidemiology and Biostatistics , University of Texas Health Science Center at San Antonio , San Antonio , TX , USA
| | - Sarah Elmore
- c Interdisciplinary Faculty of Toxicology , Texas A&M University , College Station , TX , USA
| | - Amelia Romoser
- c Interdisciplinary Faculty of Toxicology , Texas A&M University , College Station , TX , USA
| | - Lili Tang
- d Department of Environmental Health Science, College of Public Health , University of Georgia , Athens , GA , USA
| | - Min-Su Kang
- d Department of Environmental Health Science, College of Public Health , University of Georgia , Athens , GA , USA
| | - Kathy Xue
- d Department of Environmental Health Science, College of Public Health , University of Georgia , Athens , GA , USA
| | - Marisa Rodriguez
- b Department of Epidemiology and Biostatistics , University of Texas Health Science Center at San Antonio , San Antonio , TX , USA
| | - Nicole A Dierschke
- b Department of Epidemiology and Biostatistics , University of Texas Health Science Center at San Antonio , San Antonio , TX , USA
| | - Holly G Hayes
- e Arnold School of Public Health , University of South Carolina , Columbia , SC , USA
| | - H Andrew Hansen
- f Department of Clinical Surgery , Texas A&M Health Sciences Center , College Station , TX , USA
| | - Fernando Guerra
- b Department of Epidemiology and Biostatistics , University of Texas Health Science Center at San Antonio , San Antonio , TX , USA
| | - Jia-Sheng Wang
- d Department of Environmental Health Science, College of Public Health , University of Georgia , Athens , GA , USA
| | - Timothy Phillips
- c Interdisciplinary Faculty of Toxicology , Texas A&M University , College Station , TX , USA
| |
Collapse
|
42
|
Bogen KT, Heilman JM. Reassessment of MTBE cancer potency considering modes of action for MTBE and its metabolites. Crit Rev Toxicol 2016; 45 Suppl 1:1-56. [PMID: 26414780 DOI: 10.3109/10408444.2015.1052367] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
A 1999 California state agency cancer potency (CP) evaluation of methyl tert-butyl ether (MTBE) assumed linear risk extrapolations from tumor data were plausible because of limited evidence that MTBE or its metabolites could damage DNA, and based such extrapolations on data from rat gavage and rat and mouse inhalation studies indicating elevated tumor rates in male rat kidney, male rat Leydig interstitial cells, and female rat leukemia/lymphomas. More recent data bearing on MTBE cancer potency include a rodent cancer bioassay of MTBE in drinking water; several new studies of MTBE genotoxicity; several similar evaluations of MTBE metabolites, formaldehyde, and tert-butyl alcohol or TBA; and updated evaluations of carcinogenic mode(s) of action (MOAs) of MTBE and MTBE metabolite's. The lymphoma/leukemia data used in the California assessment were recently declared unreliable by the U.S. Environmental Protection Agency (EPA). Updated characterizations of MTBE CP, and its uncertainty, are currently needed to address a variety of decision goals concerning historical and current MTBE contamination. To this end, an extensive review of data sets bearing on MTBE and metabolite genotoxicity, cytotoxicity, and tumorigenicity was applied to reassess MTBE CP and related uncertainty in view of MOA considerations. Adopting the traditional approach that cytotoxicity-driven cancer MOAs are inoperative at very low, non-cytotoxic dose levels, it was determined that MTBE most likely does not increase cancer risk unless chronic exposures induce target-tissue toxicity, including in sensitive individuals. However, the corresponding expected (or plausible upper bound) CP for MTBE conditional on a hypothetical linear (e.g., genotoxic) MOA was estimated to be ∼2 × 10(-5) (or 0.003) per mg MTBE per kg body weight per day for adults exposed chronically over a lifetime. Based on this conservative estimate of CP, if MTBE is carcinogenic to humans, it is among the weakest 10% of chemical carcinogens evaluated by EPA.
Collapse
|
43
|
Yuan JM, Stepanov I, Murphy SE, Wang R, Allen S, Jensen J, Strayer L, Adams-Haduch J, Upadhyaya P, Le C, Kurzer MS, Nelson HH, Yu MC, Hatsukami D, Hecht SS. Clinical Trial of 2-Phenethyl Isothiocyanate as an Inhibitor of Metabolic Activation of a Tobacco-Specific Lung Carcinogen in Cigarette Smokers. Cancer Prev Res (Phila) 2016; 9:396-405. [PMID: 26951845 PMCID: PMC4854759 DOI: 10.1158/1940-6207.capr-15-0380] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 02/17/2016] [Indexed: 01/22/2023]
Abstract
2-Phenethyl isothiocyanate (PEITC), a natural product found as a conjugate in watercress and other cruciferous vegetables, is an inhibitor of the metabolic activation and lung carcinogenicity of the tobacco carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in F344 rats and A/J mice. We carried out a clinical trial to determine whether PEITC also inhibits the metabolic activation of NNK in smokers. Cigarette smokers were recruited and asked to smoke cigarettes containing deuterium-labeled [pyridine-D4]NNK for an acclimation period of at least 1 week. Then subjects were randomly assigned to one of two arms: PEITC followed by placebo, or placebo followed by PEITC. During the 1-week treatment period, each subject took PEITC (10 mg in 1 mL of olive oil, 4 times per day). There was a 1-week washout period between the PEITC and placebo periods. The NNK metabolic activation ratio [pyridine-D4]hydroxy acid/total [pyridine-D4]NNAL was measured in urine samples to test the hypothesis that PEITC treatment modified NNK metabolism. Eighty-two smokers completed the study and were included in the analysis. Overall, the NNK metabolic activation ratio was reduced by 7.7% with PEITC treatment (P = 0.023). The results of this trial, while modest in effect size, provide a basis for further investigation of PEITC as an inhibitor of lung carcinogenesis by NNK in smokers. Cancer Prev Res; 9(5); 396-405. ©2016 AACR.
Collapse
Affiliation(s)
- Jian-Min Yuan
- Division of Cancer Control and Population Sciences, University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania. Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Irina Stepanov
- Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota
| | - Sharon E Murphy
- Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota. Department of Biochemistry, Molecular Biology and BioPhysics, University of Minnesota, Minneapolis, Minnesota
| | - Renwei Wang
- Division of Cancer Control and Population Sciences, University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania
| | - Sharon Allen
- Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota
| | - Joni Jensen
- Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota
| | - Lori Strayer
- Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota
| | - Jennifer Adams-Haduch
- Division of Cancer Control and Population Sciences, University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania
| | - Pramod Upadhyaya
- Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota
| | - Chap Le
- Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota
| | - Mindy S Kurzer
- Department of Food Science and Nutrition, University of Minnesota, St. Paul, Minnesota
| | - Heather H Nelson
- Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota. Division of Epidemiology and Community Health, School of Public Health, University of Minnesota, Minneapolis, Minnesota
| | - Mimi C Yu
- Department of Preventive Medicine, University of Southern California Keck School of Medicine, Los Angeles, California
| | - Dorothy Hatsukami
- Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota
| | - Stephen S Hecht
- Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota.
| |
Collapse
|
44
|
Taguchi K, Takaku M, Egner PA, Morita M, Kaneko T, Mashimo T, Kensler TW, Yamamoto M. Generation of a New Model Rat: Nrf2 Knockout Rats Are Sensitive to Aflatoxin B1 Toxicity. Toxicol Sci 2016; 152:40-52. [PMID: 27071940 DOI: 10.1093/toxsci/kfw065] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
THE TRANSCRIPTION FACTOR NRF2: (NF-E2-related-factor 2) REGULATES A BATTERY OF ANTIOXIDATIVE STRESS-RESPONSE GENES AND DETOXICATION GENES, AND NRF2 KNOCKOUT LINES OF MICE HAVE BEEN CONTRIBUTING CRITICALLY TO THE CLARIFICATION OF ROLES THAT NRF2 PLAYS FOR CELL PROTECTION HOWEVER, THERE ARE APPARENT LIMITATIONS IN USE OF THE MOUSE MODELS FOR INSTANCE, RATS EXHIBIT MORE SUITABLE FEATURES FOR TOXICOLOGICAL OR PHYSIOLOGICAL EXAMINATIONS THAN MICE IN THIS STUDY, WE GENERATED 2 LINES OF NRF2 KNOCKOUT RATS BY USING A GENOME EDITING TECHNOLOGY; 1 LINE HARBORS A 7-BP DELETION Δ7 AND THE OTHER LINE HARBORS A 1-BP INSERTION +1 IN THE NRF2 GENE IN THE LIVERS OF RATS HOMOZYGOUSLY DELETING THE NRF2 GENE, AN ACTIVATOR OF NRF2 SIGNALING, CDDO-IM, COULD NOT INDUCE EXPRESSION OF REPRESENTATIVE NRF2 TARGET GENES TO EXAMINE ALTERED TOXICOLOGICAL RESPONSE, WE TREATED THE NRF2 KNOCKOUT RATS WITH AFLATOXIN B1 AFB1, A CARCINOGENIC MYCOTOXIN THAT ELICITS GENE MUTATIONS THROUGH BINDING OF ITS METABOLITES TO DNA AND FOR WHICH THE RAT HAS BEEN PROPOSED AS A REASONABLE SURROGATE FOR HUMAN TOXICITY INDEED, IN THE NRF2 KNOCKOUT RAT LIVERS THE ENZYMES OF THE AFB1 DETOXICATION PATHWAY WERE SIGNIFICANTLY DOWNREGULATED SINGLE DOSE ADMINISTRATION OF AFB1 INCREASED HEPATOTOXICITY AND BINDING OF AFB1-N7-GUANINE TO HEPATIC DNA IN NRF2 KNOCKOUT RATS COMPARED WITH WILD-TYPE NRF2 KNOCKOUT RATS REPEATEDLY TREATED WITH AFB1 WERE PRONE TO LETHALITY AND CDDO-IM WAS NO LONGER PROTECTIVE THESE RESULTS DEMONSTRATE THAT NRF2 KNOCKOUT RATS ARE QUITE SENSITIVE TO AFB1 TOXICITIES AND THIS RAT GENOTYPE EMERGES AS A NEW MODEL ANIMAL IN TOXICOLOGY.
Collapse
Affiliation(s)
- Keiko Taguchi
- *Department of Medical Biochemistry, Tohoku University Graduate School of Medicine, Aoba, Sendai 980-8575, Japan
| | - Misaki Takaku
- *Department of Medical Biochemistry, Tohoku University Graduate School of Medicine, Aoba, Sendai 980-8575, Japan
| | - Patricia A Egner
- Bloomberg School of Public Health, The Johns Hopkins University, Baltimore, Maryland 21205
| | - Masanobu Morita
- *Department of Medical Biochemistry, Tohoku University Graduate School of Medicine, Aoba, Sendai 980-8575, Japan
| | - Takehito Kaneko
- Institute of Laboratory Animals, Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan
| | - Tomoji Mashimo
- Institute of Laboratory Animals, Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan
| | - Thomas W Kensler
- Bloomberg School of Public Health, The Johns Hopkins University, Baltimore, Maryland 21205; Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania 15261
| | - Masayuki Yamamoto
- *Department of Medical Biochemistry, Tohoku University Graduate School of Medicine, Aoba, Sendai 980-8575, Japan;
| |
Collapse
|
45
|
Mathis BJ, Cui T. CDDO and Its Role in Chronic Diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 929:291-314. [PMID: 27771930 DOI: 10.1007/978-3-319-41342-6_13] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
There has been a continued interest in translational research focused on both natural products and manipulation of functional groups on these compounds to create novel derivatives with higher desired activities. Oleanolic acid, a component of traditional Chinese medicine used in hepatitis therapy, was modified by chemical processes to form 2-cyano-3,12-dioxoolean-1,9-dien-28-oic acid (CDDO). This modification increased anti-inflammatory activity significantly and additional functional groups on the CDDO backbone have shown promise in treating conditions ranging from kidney disease to obesity to diabetes. CDDO's therapeutic effect is due to its upregulation of the master antioxidant transcription factor Nuclear factor erythroid 2-related factor 2 (Nrf2) through conformational change of Nrf2-repressing, Kelch-like erythroid cell-derived protein with CNC homology-associated protein 1 (Keap1) and multiple animal and human studies have verified subsequent activation of Nrf2-controlled antioxidant genes via upstream Antioxidant Response Element (ARE) regions. At the present time, positive results have been obtained in the laboratory and clinical trials with CDDO derivatives treating conditions such as lung injury, inflammation and chronic kidney disease. However, clinical trials for cancer and cardiovascular disease have not shown equally positive results and further exploration of CDDO and its derivatives is needed to put these shortcomings into context for the purpose of future therapeutic modalities.
Collapse
Affiliation(s)
- Bryan J Mathis
- Department of Cell Biology and Anatomy, University of South Carolina School of Medicine, Columbia, South Carolina, 29208, USA
| | - Taixing Cui
- Department of Cell Biology and Anatomy, University of South Carolina School of Medicine, 6439 Garners Ferry Rd., Columbia, South Carolina, 29209, USA.
| |
Collapse
|
46
|
Klapacz J, Pottenger LH, Engelward BP, Heinen CD, Johnson GE, Clewell RA, Carmichael PL, Adeleye Y, Andersen ME. Contributions of DNA repair and damage response pathways to the non-linear genotoxic responses of alkylating agents. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2015; 767:77-91. [PMID: 27036068 DOI: 10.1016/j.mrrev.2015.11.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 11/26/2015] [Accepted: 11/27/2015] [Indexed: 11/27/2022]
Abstract
From a risk assessment perspective, DNA-reactive agents are conventionally assumed to have genotoxic risks at all exposure levels, thus applying a linear extrapolation for low-dose responses. New approaches discussed here, including more diverse and sensitive methods for assessing DNA damage and DNA repair, strongly support the existence of measurable regions where genotoxic responses with increasing doses are insignificant relative to control. Model monofunctional alkylating agents have in vitro and in vivo datasets amenable to determination of points of departure (PoDs) for genotoxic effects. A session at the 2013 Society of Toxicology meeting provided an opportunity to survey the progress in understanding the biological basis of empirically-observed PoDs for DNA alkylating agents. Together with the literature published since, this review discusses cellular pathways activated by endogenous and exogenous alkylation DNA damage. Cells have evolved conserved processes that monitor and counteract a spontaneous steady-state level of DNA damage. The ubiquitous network of DNA repair pathways serves as the first line of defense for clearing of the DNA damage and preventing mutation. Other biological pathways discussed here that are activated by genotoxic stress include post-translational activation of cell cycle networks and transcriptional networks for apoptosis/cell death. The interactions of various DNA repair and DNA damage response pathways provide biological bases for the observed PoD behaviors seen with genotoxic compounds. Thus, after formation of DNA adducts, the activation of cellular pathways can lead to the avoidance of a mutagenic outcome. The understanding of the cellular mechanisms acting within the low-dose region will serve to better characterize risks from exposures to DNA-reactive agents at environmentally-relevant concentrations.
Collapse
Affiliation(s)
- Joanna Klapacz
- Toxicology & Environmental Research and Consulting, The Dow Chemical Company, Midland, MI 48674, USA.
| | - Lynn H Pottenger
- Toxicology & Environmental Research and Consulting, The Dow Chemical Company, Midland, MI 48674, USA; Current Address: Olin Corporation, Midland, MI 48674, USA
| | - Bevin P Engelward
- Department of Biological Engineering, MA Institute of Technology, Cambridge, MA 02139, USA
| | - Christopher D Heinen
- Center for Molecular Medicine, Neag Comprehensive Cancer Center, University of CT Health Center, Farmington, CT 06030, USA
| | - George E Johnson
- Institute of Life Science, College of Medicine, Swansea University, SA2 8PP, UK
| | - Rebecca A Clewell
- Hamner Institutes for Health Sciences, Research Triangle Park, NC 27709, USA
| | - Paul L Carmichael
- Unilever, Safety & Environmental Assurance Centre, Colworth Science Park, Sharnbrook, Bedfordshire MK44 1LQ, UK
| | - Yeyejide Adeleye
- Unilever, Safety & Environmental Assurance Centre, Colworth Science Park, Sharnbrook, Bedfordshire MK44 1LQ, UK
| | - Melvin E Andersen
- Hamner Institutes for Health Sciences, Research Triangle Park, NC 27709, USA
| |
Collapse
|
47
|
Liu Y, Yin T, Feng Y, Cona MM, Huang G, Liu J, Song S, Jiang Y, Xia Q, Swinnen JV, Bormans G, Himmelreich U, Oyen R, Ni Y. Mammalian models of chemically induced primary malignancies exploitable for imaging-based preclinical theragnostic research. Quant Imaging Med Surg 2015; 5:708-29. [PMID: 26682141 PMCID: PMC4671963 DOI: 10.3978/j.issn.2223-4292.2015.06.01] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Accepted: 06/15/2015] [Indexed: 12/14/2022]
Abstract
Compared with transplanted tumor models or genetically engineered cancer models, chemically induced primary malignancies in experimental animals can mimic the clinical cancer progress from the early stage on. Cancer caused by chemical carcinogens generally develops through three phases namely initiation, promotion and progression. Based on different mechanisms, chemical carcinogens can be divided into genotoxic and non-genotoxic ones, or complete and incomplete ones, usually with an organ-specific property. Chemical carcinogens can be classified upon their origins such as environmental pollutants, cooked meat derived carcinogens, N-nitroso compounds, food additives, antineoplastic agents, naturally occurring substances and synthetic carcinogens, etc. Carcinogen-induced models of primary cancers can be used to evaluate the diagnostic/therapeutic effects of candidate drugs, investigate the biological influential factors, explore preventive measures for carcinogenicity, and better understand molecular mechanisms involved in tumor initiation, promotion and progression. Among commonly adopted cancer models, chemically induced primary malignancies in mammals have several advantages including the easy procedures, fruitful tumor generation and high analogy to clinical human primary cancers. However, in addition to the time-consuming process, the major drawback of chemical carcinogenesis for translational research is the difficulty in noninvasive tumor burden assessment in small animals. Like human cancers, tumors occur unpredictably also among animals in terms of timing, location and the number of lesions. Thanks to the availability of magnetic resonance imaging (MRI) with various advantages such as ionizing-free scanning, superb soft tissue contrast, multi-parametric information, and utility of diverse contrast agents, now a workable solution to this bottleneck problem is to apply MRI for noninvasive detection, diagnosis and therapeutic monitoring on those otherwise uncontrollable animal models with primary cancers. Moreover, it is foreseeable that the combined use of chemically induced primary cancer models and molecular imaging techniques may help to develop new anticancer diagnostics and therapeutics.
Collapse
|
48
|
Cao M, Onyango EO, Williams CR, Royce DB, Gribble GW, Sporn MB, Liby KT. Novel synthetic pyridyl analogues of CDDO-Imidazolide are useful new tools in cancer prevention. Pharmacol Res 2015; 100:135-47. [PMID: 26238177 DOI: 10.1016/j.phrs.2015.07.024] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 07/24/2015] [Accepted: 07/26/2015] [Indexed: 01/07/2023]
Abstract
Two new analogues of CDDO-Imidazolide (CDDO-Im), namely 1-[2-Cyano-3,12-dioxooleana-1,9(11)-dien-28-oyl]-4(-pyridin-2-yl)-1H-imidazole ("CDDO-2P-Im") and 1-[2-Cyano-3,12-dioxooleana-1,9(11)-dien-28-oyl]-4(-pyridin-3-yl)-1H-imidazole ("CDDO-3P-Im") have been synthesized and tested for their potential use as chemopreventive drugs. At nanomolar concentrations, they were equipotent to CDDO-Im for inducing differentiation and apoptosis in U937 leukemia cells. As inflammation and oxidative stress contribute to carcinogenesis, we also assessed their cytoprotective potential. The new compounds suppressed inducible nitric oxide synthase (iNOS) expression in RAW264.7 macrophage-like cells and significantly elevated heme oxygenase-1 (HO-1) and quinone reductase (NQO1) mRNA and protein levels in various mouse tissues in vivo. Most importantly, pharmacokinetic studies performed in vitro in human plasma and in vivo showed that each new analogue was more stable than CDDO-Im. Much higher concentrations of the new derivatives were found in mouse liver, lung, pancreas and kidney after gavage in contrast to CDDO-Im. Because of their better bioavailability and their excellent anti-inflammatory profile in vitro, CDDO-2P-Im and CDDO-3P-Im were tested for prevention in a highly relevant mouse lung cancer model, in which A/J mice develop lung carcinomas after injection of vinyl carbamate, a potent carcinogen. CDDO-2P-Im and CDDO-3P-Im were as effective as CDDO-Im for reducing the size and the severity of the lung tumors.
Collapse
Affiliation(s)
- Martine Cao
- Department of Pharmacology and Toxicology, Dartmouth Medical School, Hanover, NH, USA
| | - Evans O Onyango
- Department of Chemistry, Dartmouth College, Hanover, NH, USA
| | - Charlotte R Williams
- Department of Pharmacology and Toxicology, Dartmouth Medical School, Hanover, NH, USA
| | - Darlene B Royce
- Department of Pharmacology and Toxicology, Dartmouth Medical School, Hanover, NH, USA
| | | | - Michael B Sporn
- Department of Pharmacology and Toxicology, Dartmouth Medical School, Hanover, NH, USA
| | - Karen T Liby
- Department of Pharmacology and Toxicology, Dartmouth Medical School, Hanover, NH, USA.
| |
Collapse
|
49
|
Harutyunyan T, Hovhannisyan G, Babayan N, Othman MA, Liehr T, Aroutiounian R. Influence of aflatoxin B1 on copy number variants in human leukocytes in vitro. Mol Cytogenet 2015; 8:25. [PMID: 25901182 PMCID: PMC4404608 DOI: 10.1186/s13039-015-0131-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 02/25/2015] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Aflatoxin B1 (AFB1) is a mycotoxin produced by Aspergillus spec. The latter are worldwide contaminants of food with mutagenic and carcinogenic activities in animals and humans. AFB1 was shown to have deleterious effects on metabolism of eukaryotes in many model systems, including the ability to inhibit DNA replication. An agent that disturbs DNA replication may also have the potential to induce de novo DNA copy number variations (CNVs). RESULTS Blood samples of three clinically healthy carriers were treated in vitro with AFB1 and chromosome preparations were subjected to parental origin determination fluorescence in situ hybridization (pod-FISH). Probes able to visualize CNVs in 8p21.2 and 15q11.2 were applied. In this setting here for the first time an influence of AFB1 on molecular-cytogenetically detectable CNVs could be shown. CONCLUSIONS The obtained results indicate that: (i) pod-FISH is a single cell directed, sensitive and suitable method for the analysis of mutagen induced CNVs, (ii) AFB1 has the potential to induce in vitro instability of known CNVs in human leukocytes.
Collapse
Affiliation(s)
- Tigran Harutyunyan
- Department of Genetics and Cytology, Yerevan State University, 1 Alex Manoogian, 0025 Yerevan, Armenia
| | - Galina Hovhannisyan
- Department of Genetics and Cytology, Yerevan State University, 1 Alex Manoogian, 0025 Yerevan, Armenia
| | - Nelly Babayan
- Department of Genetics and Cytology, Yerevan State University, 1 Alex Manoogian, 0025 Yerevan, Armenia ; Institute of Molecular Biology, National Academy of Sciences, 7 Hasratyan, 0014 Yerevan, Armenia
| | - Moneeb Ak Othman
- Institute of Human Genetics, Jena University Hospital, Friedrich Schiller University, Kollegiengasse 10, Jena, D-07743 Germany
| | - Thomas Liehr
- Institute of Human Genetics, Jena University Hospital, Friedrich Schiller University, Kollegiengasse 10, Jena, D-07743 Germany
| | - Rouben Aroutiounian
- Department of Genetics and Cytology, Yerevan State University, 1 Alex Manoogian, 0025 Yerevan, Armenia
| |
Collapse
|
50
|
Corcuera LA, Vettorazzi A, Arbillaga L, Pérez N, Gil AG, Azqueta A, González-Peñas E, García-Jalón JA, López de Cerain A. Genotoxicity of Aflatoxin B1 and Ochratoxin A after simultaneous application of the in vivo micronucleus and comet assay. Food Chem Toxicol 2014; 76:116-24. [PMID: 25530104 DOI: 10.1016/j.fct.2014.12.003] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Revised: 11/20/2014] [Accepted: 12/03/2014] [Indexed: 10/24/2022]
Abstract
Aflatoxin B1 (AFB1) and Ochratoxin A (OTA) are genotoxic mycotoxins that can contaminate a variety of foodstuffs, the liver and the kidney being their target organs, respectively. The micronucleus (MN) assay (bone marrow) and the comet assay (liver and kidney) were performed simultaneously in F344 rats, treated with AFB1 (0.25 mg/kg b.w.), OTA (0.5 mg/kg b.w.) or both mycotoxins. After AFB1 treatment, histopathology and biochemistry analysis showed liver necrosis, focal inflammation and an increase in Alanine Aminotransferase and Aspartate Aminotransferase. OTA alone did not cause any alteration. The acute hepatotoxic effects caused by AFB1 were less pronounced in animals treated with both mycotoxins. With regard to the MN assay, after 24 h, positive results were obtained for AFB1 and negative results were obtained for OTA, although both toxins caused bone marrow toxicity. In the combined treatment, OTA reduced the toxicity and the number of MN produced by AFB1. In the comet assay, after 3 h, positive results were obtained for AFB1 in the liver and for OTA in the kidney. The combined treatment reduced DNA damage in the liver and had no influence in the kidney. Altogether, these results may be indicative of an antagonistic relationship regarding the genotoxicity of both mycotoxins.
Collapse
Affiliation(s)
- Laura-Ana Corcuera
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, University of Navarra, Irunlarrea 1, 31008 Pamplona, Spain
| | - Ariane Vettorazzi
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, University of Navarra, Irunlarrea 1, 31008 Pamplona, Spain
| | - Leire Arbillaga
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, University of Navarra, Irunlarrea 1, 31008 Pamplona, Spain
| | - Noemí Pérez
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, University of Navarra, Irunlarrea 1, 31008 Pamplona, Spain
| | - Ana Gloria Gil
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, University of Navarra, Irunlarrea 1, 31008 Pamplona, Spain
| | - Amaya Azqueta
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, University of Navarra, Irunlarrea 1, 31008 Pamplona, Spain
| | - Elena González-Peñas
- Department of Organic and Pharmaceutical Chemistry, Faculty of Pharmacy, University of Navarra, Irunlarrea 1, 31008, Pamplona, Spain
| | - Jose Antonio García-Jalón
- Department of Animal Pathology, Faculty of Veterinary, University of Zaragoza, C/Miguel Servet 177, 50013 Zaragoza, Spain
| | - Adela López de Cerain
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, University of Navarra, Irunlarrea 1, 31008 Pamplona, Spain.
| |
Collapse
|