1
|
Luo J, Zhu WC, Chen QX, Yang CF, Huang BJ, Zhang SJ. A prognostic model based on DNA methylation-related gene expression for predicting overall survival in hepatocellular carcinoma. Front Oncol 2024; 13:1171932. [PMID: 38304027 PMCID: PMC10830715 DOI: 10.3389/fonc.2023.1171932] [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: 05/02/2023] [Accepted: 12/27/2023] [Indexed: 02/03/2024] Open
Abstract
Background Hepatocellular carcinoma (HCC) continues to increase in morbidity and mortality among all types of cancer. DNA methylation, an important epigenetic modification, is associated with cancer occurrence and progression. The objective of this study was to establish a model based on DNA methylation risk scores for identifying new potential therapeutic targets in HCC and preventing cancer progression. Methods Transcriptomic, clinical, and DNA methylation data on 374 tumor tissues and 50 adjacent normal tissues were downloaded from The Cancer Genome Atlas-Liver Hepatocellular Carcinoma database. The gene expression profiles of the GSE54236 liver cancer dataset, which contains data on 161 liver tissue samples, were obtained from the Gene Expression Omnibus database. We analyzed the relationship between DNA methylation and gene expression levels after identifying the differentially methylated and expressed genes. Then, we developed and validated a risk score model based on the DNA methylation-driven genes. A tissue array consisting of 30 human hepatocellular carcinoma samples and adjacent normal tissues was used to assess the protein and mRNA expression levels of the marker genes by immunohistochemistry and qRT-PCR, respectively. Results Three methylation-related differential genes were identified in our study: GLS, MEX3B, and GNA14. The results revealed that their DNA methylation levels were negatively correlated with local gene expression regulation. The gene methylation levels correlated strongly with the prognosis of patients with liver cancer. This was confirmed by qRT-PCR and immunohistochemical verification of the expression of these genes or proteins in tumors and adjacent tissues. These results revealed the relationship between the level of relevant gene methylation and the prognosis of patients with liver cancer as well as the underlying cellular and biological mechanisms. This allows our gene signature to provide more accurate and appropriate predictions for clinical applications. Conclusion Through bioinformatics analysis and experimental validation, we obtained three DNA methylation marker: GLS, MEX3B, and GNA14. This helps to predict the prognosis and may be a potential therapeutic target for HCC patients.
Collapse
Affiliation(s)
- Jin Luo
- Department of Traditional Chinese Medicine, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
- Department of Traditional Chinese Medicine, Shenzhen Children’s Hospital, Shenzhen, Guangdong, China
| | - Wan-Cui Zhu
- State Key Laboratory of Oncology in South China, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Sun Yat-sen University Cancer Center, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China
| | - Qiu-Xia Chen
- Department of Traditional Chinese Medicine, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Chang-Fu Yang
- Department of Oncology, The People’s Hospital of Gaozhou, Gaozhou, China
| | - Bi-Jun Huang
- Department of Experimental Research, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-Sen University Cancer Center, Guangzhou, China
| | - Shi-Jun Zhang
- Department of Traditional Chinese Medicine, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| |
Collapse
|
2
|
Hori T, Yokobori K, Moore R, Negishi M, Sueyoshi T. CAR requires Gadd45β to promote phenobarbital-induced mouse liver tumors in early stage. Front Oncol 2023; 13:1217847. [PMID: 37746289 PMCID: PMC10516603 DOI: 10.3389/fonc.2023.1217847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 08/17/2023] [Indexed: 09/26/2023] Open
Abstract
Phenobarbital (PB) is an archetypal substance used as a mouse hepatocellular carcinoma (HCC) promotor in established experimental protocols. Our previous results showed CAR is the essential factor for PB induced HCC promotion. Subsequent studies suggested Gadd45β, which is induced by PB through CAR activation, is collaborating with CAR to repress TNF-α induced cell death. Here, we used Gadd45β null mice (Gadd45β KO) treated with N-diethylnitrosamine (DEN) at 5 weeks of age and kept the mice with PB supplemented drinking water from 7 to 57 weeks old. Compared with wild type mice, Gadd45β KO mice developed no HCC in the PB treated group. Increases in liver weight were more prominent in wild type mice than KO mice. Microarray analysis of mRNA derived from mouse livers found multiple genes specifically up or down regulated in wild type mice but not null mice in DEN + PB groups. Further qPCR analysis confirmed two genes, Tgfbr2 and irisin/Fndc5, were up-regulated in PB treated wild type mice but no significant increase was observed in Gadd45β KO mice. We focused on these two genes because previous reports showed that hepatic Irisin/Fndc5 expression was significantly higher in HCC patients and that irisin binds to TGF-β receptor complex that includes TGFBR2 subunit. Our results revealed irisin peptide in cell culture media increased the growth rate of mouse hepatocyte-derived AML12 cells. Microarray analysis revealed that irisin-regulated genes in AML12 cells showed a significant association with the genes in the TGF-β pathway. Expression of irisin/Fndc5 and Tgfbr2 induced growth of human HCC cell line HepG2. Thus, Gadd45β plays an indispensable role in mouse HCC development regulating the irisin/Fndc5 and Tgfbr2 genes.
Collapse
Affiliation(s)
- Takeshi Hori
- Pharmacogenetics Section, Reproductive and Developmental Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health,
Research Triangle Park, NC, United States
- Department of Biomechanics, Institute of Biomaterials and Bioengineering (IBB), Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Kosuke Yokobori
- Pharmacogenetics Section, Reproductive and Developmental Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health,
Research Triangle Park, NC, United States
| | - Rick Moore
- Pharmacogenetics Section, Reproductive and Developmental Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health,
Research Triangle Park, NC, United States
| | - Masahiko Negishi
- Pharmacogenetics Section, Reproductive and Developmental Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health,
Research Triangle Park, NC, United States
| | - Tatsuya Sueyoshi
- Pharmacogenetics Section, Reproductive and Developmental Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health,
Research Triangle Park, NC, United States
| |
Collapse
|
3
|
Wang M, Ye Q, Mao D, Li H. Research Progress in Liver-Regenerating Microenvironment and DNA Methylation in Hepatocellular Carcinoma: The Role of Traditional Chinese Medicine. Med Sci Monit 2020; 26:e920310. [PMID: 32144233 PMCID: PMC7077739 DOI: 10.12659/msm.920310] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The development, progression, recurrence, and metastasis of hepatocellular carcinoma (HCC) are closely associated with an abnormal liver-regenerating microenvironment (LRM). Therefore, preventing and reversing an abnormal LRM is a potential therapeutic strategy against HCC. Studies are increasingly focusing on the impact of regeneration, fibrosis, angiogenesis, inflammation, immunomodulation, and hepatic stem cells on HCC development and progression. As a key epigenetic mechanism, DNA methylation is extensively involved in regulating physiological and pathological pathways. In this review, we summarize recent findings on the role of DNA methylation in the fibrotic, angiogenic, inflammatory/immune, and stem cell microenvironments of HCC, and discuss new advances in Traditional Chinese Medicine (TCM) on influencing the abnormal LRM, so as to gain new insights into alleviating the abnormal LRM via regulating DNA methylation by TCM.
Collapse
Affiliation(s)
- Minggang Wang
- Hubei University of Traditional Chinese Medicine, Wuhan, Hubei, China (mainland)
| | - Qianling Ye
- Guangxi University of Traditional Chinese Medicine, Nanning, Guangxi, China (mainland)
| | - Dewen Mao
- The First Affiliated Hospital of Guangxi University of Traditional Chinese Medicine, Nanning, Guangxi, China (mainland)
| | - Hanmin Li
- Hubei University of Traditional Chinese Medicine, Wuhan, Hubei, China (mainland)
| |
Collapse
|
4
|
Moggs J, Terranova R. Chromatin dynamics underlying latent responses to xenobiotics. Toxicol Res (Camb) 2018; 7:606-617. [PMID: 30090610 PMCID: PMC6062062 DOI: 10.1039/c7tx00317j] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 02/26/2018] [Indexed: 11/21/2022] Open
Abstract
Pleiotropic xenobiotics can trigger dynamic alterations in mammalian chromatin structure and function but many of these are likely non-adverse and simply reflect short-term changes in DNA transactions underlying normal homeostatic, adaptive and protective cellular responses. However, it is plausible that a subset of xenobiotic-induced perturbations of somatic tissue or germline epigenomes result in delayed-onset and long-lasting adverse effects, in particular if they occur during critical stages of growth and development. These could include reprogramming, dedifferentiation, uncontrolled growth, and cumulative toxicity effects through molecular memory of prior xenobiotic exposures or altered susceptibility to subsequent xenobiotic exposures. Here we discuss the current evidence for epigenetic mechanisms underlying latent responses to xenobiotics, and the potential for identifying molecular epigenetic changes that are prodromal to overt morphologic or functional toxicity phenotypes.
Collapse
Affiliation(s)
- Jonathan Moggs
- Preclinical Safety , Translational Medicine , Novartis Institutes for BioMedical Research , Basel , Switzerland
| | - Rémi Terranova
- Preclinical Safety , Translational Medicine , Novartis Institutes for BioMedical Research , Basel , Switzerland
| |
Collapse
|
5
|
Yamada T. Case examples of an evaluation of the human relevance of the pyrethroids/pyrethrins-induced liver tumours in rodents based on the mode of action. Toxicol Res (Camb) 2018; 7:681-696. [PMID: 30090614 PMCID: PMC6062351 DOI: 10.1039/c7tx00288b] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 01/10/2018] [Indexed: 01/01/2023] Open
Abstract
Rodent carcinogenicity studies are useful for screening for human carcinogens but they are not perfect. Some modes of action (MOAs) lead to cancers in both experimental rodents and humans, but others that lead to cancers in rodents do not do so in humans. Therefore, analysing the MOAs by which chemicals produce tumours in rodents and determining the relevance of such tumour data for human risk are critical. Recently, experimental data were obtained as case examples of an evaluation of the human relevance of pyrethroid (metofluthrin and momfluorothrin)- and pyrethrins-induced liver tumours in rats based on MOA. The MOA analysis, based on the International Programme on Chemical Safety (IPCS) framework, concluded that experimental data strongly support that the postulated MOA for metofluthrin-, momfluorothrin- and pyrethrins-produced rat hepatocellular tumours is mediated by constitutive androstane receptor (CAR) activation. Since metofluthrin and momfluorothrin are close structural analogues, reproducible outcomes for both chemicals provide confidence in the MOA findings. Furthermore, cultured human hepatocyte studies and humanized chimeric mouse liver studies demonstrated species difference between human hepatocytes (refractory to the mitogenic effects of these compounds) and rat hepatocytes (sensitive to their mitogenic effects). These data strongly support the hypothesis that the CAR-mediated MOA for liver tumorigenesis is of low carcinogenic risk for humans. In this research, in addition to cultured human hepatocyte studies, the usefulness of the humanized chimeric liver mouse models was clearly demonstrated. These data substantially influenced decisions in regulatory toxicology. In this review I comprehensively discuss the human relevance of the CAR-mediated MOA for rodent liver tumorigenesis based on published information, including our recent molecular research on CAR-mediated MOA.
Collapse
Affiliation(s)
- Tomoya Yamada
- Environmental Health Science Laboratory , Sumitomo Chemical Co. , Ltd , 1-98 , 3-Chome , Kasugade-Naka , Konohana-ku , Osaka 554-8558 , Japan . ; ; Tel: +81-66466-5322
| |
Collapse
|
6
|
Mahna D, Puri S, Sharma S. DNA methylation signatures: Biomarkers of drug and alcohol abuse. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2018; 777:19-28. [DOI: 10.1016/j.mrrev.2018.06.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 05/22/2018] [Accepted: 06/18/2018] [Indexed: 01/08/2023]
|
7
|
Bogen KT. Biphasic hCAR Inhibition-Activation by Two Aminoazo Liver Carcinogens. NUCLEAR RECEPTOR RESEARCH 2018. [DOI: 10.11131/2018/101321] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
|
8
|
Ohara A, Takahashi Y, Kondo M, Okuda Y, Takeda S, Kushida M, Kobayashi K, Sumida K, Yamada T. Candidate genes responsible for early key events of phenobarbital-promoted mouse hepatocellular tumorigenesis based on differentiation of regulating genes between wild type mice and humanized chimeric mice. Toxicol Res (Camb) 2017; 6:795-813. [PMID: 30090543 PMCID: PMC6062386 DOI: 10.1039/c7tx00163k] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Accepted: 08/23/2017] [Indexed: 12/12/2022] Open
Abstract
Phenobarbital (PB) is a nongenotoxic hepatocellular carcinogen in rodents. PB induces hepatocellular tumors by activating the constitutive androstane receptor (CAR). Some previous research has suggested the possible involvement of epigenetic regulation in PB-promoted hepatocellular tumorigenesis, but the details of its molecular mechanism are not fully understood. In the present study, comprehensive analyses of DNA methylation, hydroxymethylation and gene expression using microarrays were performed in mouse hepatocellular adenomas induced by a single 90 mg kg-1 intraperitoneal injection dose of diethylnitrosamine (DEN) followed by 500 ppm PB in the diet for 27 weeks. DNA modification and expression of hundreds of genes are coordinately altered in PB-induced mouse hepatocellular adenomas. Of these, gene network analysis showed alterations of CAR signaling and tumor development-related genes. Pathway enrichment analysis revealed that differentially methylated or hydroxymethylated genes belong mainly to pathways involved in development, immune response and cancer cells in contrast to differentially expressed genes belonging primarily to the cell cycle. Furthermore, overlap was evaluated between the genes with altered expression levels with 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC) alterations in mouse hepatocellular adenoma induced by DEN/PB and the genes with altered expression levels in the liver of CD-1 mice or humanized chimeric mice treated with PB for 7 days. With the integration of transcriptomic and epigenetic approaches, we detected candidate genes responsible for early key events of PB-promoted mouse hepatocellular tumorigenesis. Interestingly, these genes did not overlap with genes altered by the PB treatment of humanized chimeric mice, thus suggesting a species difference between the effects of PB in mouse and human hepatocytes.
Collapse
Affiliation(s)
- Ayako Ohara
- Environmental Health Science Laboratory , Sumitomo Chemical Co. , Ltd. , 1-98 , 3-Chome , Kasugade-Naka , Konohana-ku , Osaka 554-8558 , Japan . ; ; Tel: +81-66466-5322
| | - Yasuhiko Takahashi
- Environmental Health Science Laboratory , Sumitomo Chemical Co. , Ltd. , 1-98 , 3-Chome , Kasugade-Naka , Konohana-ku , Osaka 554-8558 , Japan . ; ; Tel: +81-66466-5322
| | - Miwa Kondo
- Environmental Health Science Laboratory , Sumitomo Chemical Co. , Ltd. , 1-98 , 3-Chome , Kasugade-Naka , Konohana-ku , Osaka 554-8558 , Japan . ; ; Tel: +81-66466-5322
| | - Yu Okuda
- Environmental Health Science Laboratory , Sumitomo Chemical Co. , Ltd. , 1-98 , 3-Chome , Kasugade-Naka , Konohana-ku , Osaka 554-8558 , Japan . ; ; Tel: +81-66466-5322
| | - Shuji Takeda
- Environmental Health Science Laboratory , Sumitomo Chemical Co. , Ltd. , 1-98 , 3-Chome , Kasugade-Naka , Konohana-ku , Osaka 554-8558 , Japan . ; ; Tel: +81-66466-5322
| | - Masahiko Kushida
- Environmental Health Science Laboratory , Sumitomo Chemical Co. , Ltd. , 1-98 , 3-Chome , Kasugade-Naka , Konohana-ku , Osaka 554-8558 , Japan . ; ; Tel: +81-66466-5322
| | - Kentaro Kobayashi
- Environmental Health Science Laboratory , Sumitomo Chemical Co. , Ltd. , 1-98 , 3-Chome , Kasugade-Naka , Konohana-ku , Osaka 554-8558 , Japan . ; ; Tel: +81-66466-5322
| | - Kayo Sumida
- Environmental Health Science Laboratory , Sumitomo Chemical Co. , Ltd. , 1-98 , 3-Chome , Kasugade-Naka , Konohana-ku , Osaka 554-8558 , Japan . ; ; Tel: +81-66466-5322
| | - Tomoya Yamada
- Environmental Health Science Laboratory , Sumitomo Chemical Co. , Ltd. , 1-98 , 3-Chome , Kasugade-Naka , Konohana-ku , Osaka 554-8558 , Japan . ; ; Tel: +81-66466-5322
| |
Collapse
|
9
|
Miousse IR, Murphy LA, Lin H, Schisler MR, Sun J, Chalbot MCG, Sura R, Johnson K, LeBaron MJ, Kavouras IG, Schnackenberg LK, Beger RD, Rasoulpour RJ, Koturbash I. Dose-response analysis of epigenetic, metabolic, and apical endpoints after short-term exposure to experimental hepatotoxicants. Food Chem Toxicol 2017; 109:690-702. [PMID: 28495587 DOI: 10.1016/j.fct.2017.05.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 05/05/2017] [Accepted: 05/07/2017] [Indexed: 12/16/2022]
Abstract
Identification of sensitive and novel biomarkers or endpoints associated with toxicity and carcinogenesis is of a high priority. There is increasing interest in the incorporation of epigenetic and metabolic biomarkers to complement apical data; however, a number of questions, including the tissue specificity, dose-response patterns, early detection of those endpoints, and the added value need to be addressed. In this study, we investigated the dose-response relationship between apical, epigenetic, and metabolomics endpoints following short-term exposure to experimental hepatotoxicants, clofibrate (CF) and phenobarbital (PB). Male F344 rats were exposed to PB (0, 5, 25, and 100 mg/kg/day) or CF (0, 10, 50, and 250 mg/kg/day) for seven days. Exposure to PB or CF resulted in dose-dependent increases in relative liver weights, hepatocellular hypertrophy and proliferation, and increases in Cyp2b1 and Cyp4a1 transcripts. These changes were associated with altered histone modifications within the regulatory units of cytochrome genes, LINE-1 DNA hypomethylation, and altered microRNA profiles. Metabolomics data indicated alterations in the metabolism of bile acids. This study provides the first comprehensive analysis of the apical, epigenetic and metabolic alterations, and suggests that the latter two occur within or near the dose response curve of apical endpoint alterations following exposure to experimental hepatotoxicants.
Collapse
Affiliation(s)
- Isabelle R Miousse
- Department of Environmental and Occupational Health, College of Public Health, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA.
| | - Lynea A Murphy
- Toxicology and Environmental Research & Consulting, The Dow Chemical Company, Midland, MI, USA.
| | - Haixia Lin
- Department of Environmental and Occupational Health, College of Public Health, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA.
| | - Melissa R Schisler
- Toxicology and Environmental Research & Consulting, The Dow Chemical Company, Midland, MI, USA.
| | - Jinchun Sun
- Division of Systems Biology, National Center for Toxicological Research, US Food and Drug Administration, Jefferson, AR 72079, USA.
| | - Marie-Cecile G Chalbot
- Department of Environmental Health Sciences, Ryals School of Public Health, University of Alabama at Birmingham, 1665 University Blvd, Birmingham, AL 35246, USA.
| | - Radhakrishna Sura
- Toxicology and Environmental Research & Consulting, The Dow Chemical Company, Midland, MI, USA.
| | - Kamin Johnson
- Toxicology and Environmental Research & Consulting, The Dow Chemical Company, Midland, MI, USA.
| | - Matthew J LeBaron
- Toxicology and Environmental Research & Consulting, The Dow Chemical Company, Midland, MI, USA.
| | - Ilias G Kavouras
- Department of Environmental Health Sciences, Ryals School of Public Health, University of Alabama at Birmingham, 1665 University Blvd, Birmingham, AL 35246, USA.
| | - Laura K Schnackenberg
- Division of Systems Biology, National Center for Toxicological Research, US Food and Drug Administration, Jefferson, AR 72079, USA.
| | - Richard D Beger
- Division of Systems Biology, National Center for Toxicological Research, US Food and Drug Administration, Jefferson, AR 72079, USA.
| | - Reza J Rasoulpour
- Toxicology and Environmental Research & Consulting, The Dow Chemical Company, Midland, MI, USA.
| | - Igor Koturbash
- Department of Environmental and Occupational Health, College of Public Health, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA.
| |
Collapse
|
10
|
Terranova R, Vitobello A, Del Rio Espinola A, Wolf CR, Schwarz M, Thomson J, Meehan R, Moggs J. Progress in identifying epigenetic mechanisms of xenobiotic-induced non-genotoxic carcinogenesis. CURRENT OPINION IN TOXICOLOGY 2017. [DOI: 10.1016/j.cotox.2017.06.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
|
11
|
Cherian MT, Chai SC, Chen T. Small-molecule modulators of the constitutive androstane receptor. Expert Opin Drug Metab Toxicol 2015; 11:1099-114. [PMID: 25979168 DOI: 10.1517/17425255.2015.1043887] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
INTRODUCTION The constitutive androstane receptor (CAR) induces drug-metabolizing enzymes for xenobiotic metabolism. AREAS COVERED This review covers recent advances in elucidating the biological functions of CAR and its modulation by a growing number of agonists and inhibitors. EXPERT OPINION Extrapolation of animal CAR function to that of humans should be carefully scrutinized, particularly when rodents are used in evaluating the metabolic profile and carcinogenic properties of clinical drugs and environmental chemicals. Continuous efforts are needed to discover novel CAR inhibitors, with extensive understanding of their inhibitory mechanism, species selectivity, and discriminating power against other xenobiotic sensors.
Collapse
Affiliation(s)
- Milu T Cherian
- Postdoctoral fellow, St. Jude Children's Research Hospital, Department of Chemical Biology and Therapeutics , 262 Danny Thomas Place, Memphis, TN 38105 , USA
| | | | | |
Collapse
|
12
|
Luisier R, Lempiäinen H, Scherbichler N, Braeuning A, Geissler M, Dubost V, Müller A, Scheer N, Chibout SD, Hara H, Picard F, Theil D, Couttet P, Vitobello A, Grenet O, Grasl-Kraupp B, Ellinger-Ziegelbauer H, Thomson JP, Meehan RR, Elcombe CR, Henderson CJ, Wolf CR, Schwarz M, Moulin P, Terranova R, Moggs JG. Phenobarbital induces cell cycle transcriptional responses in mouse liver humanized for constitutive androstane and pregnane x receptors. Toxicol Sci 2014; 139:501-11. [PMID: 24690595 DOI: 10.1093/toxsci/kfu038] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The constitutive androstane receptor (CAR) and the pregnane X receptor (PXR) are closely related nuclear receptors involved in drug metabolism and play important roles in the mechanism of phenobarbital (PB)-induced rodent nongenotoxic hepatocarcinogenesis. Here, we have used a humanized CAR/PXR mouse model to examine potential species differences in receptor-dependent mechanisms underlying liver tissue molecular responses to PB. Early and late transcriptomic responses to sustained PB exposure were investigated in liver tissue from double knock-out CAR and PXR (CAR(KO)-PXR(KO)), double humanized CAR and PXR (CAR(h)-PXR(h)), and wild-type C57BL/6 mice. Wild-type and CAR(h)-PXR(h) mouse livers exhibited temporally and quantitatively similar transcriptional responses during 91 days of PB exposure including the sustained induction of the xenobiotic response gene Cyp2b10, the Wnt signaling inhibitor Wisp1, and noncoding RNA biomarkers from the Dlk1-Dio3 locus. Transient induction of DNA replication (Hells, Mcm6, and Esco2) and mitotic genes (Ccnb2, Cdc20, and Cdk1) and the proliferation-related nuclear antigen Mki67 were observed with peak expression occurring between 1 and 7 days PB exposure. All these transcriptional responses were absent in CAR(KO)-PXR(KO) mouse livers and largely reversible in wild-type and CAR(h)-PXR(h) mouse livers following 91 days of PB exposure and a subsequent 4-week recovery period. Furthermore, PB-mediated upregulation of the noncoding RNA Meg3, which has recently been associated with cellular pluripotency, exhibited a similar dose response and perivenous hepatocyte-specific localization in both wild-type and CAR(h)-PXR(h) mice. Thus, mouse livers coexpressing human CAR and PXR support both the xenobiotic metabolizing and the proliferative transcriptional responses following exposure to PB.
Collapse
Affiliation(s)
- Raphaëlle Luisier
- Preclinical Safety, Novartis Institutes for Biomedical Research, CH-4057 Basel, Switzerland
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Mirbahai L, Chipman JK. Epigenetic memory of environmental organisms: A reflection of lifetime stressor exposures. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2014; 764-765:10-7. [DOI: 10.1016/j.mrgentox.2013.10.003] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Accepted: 10/09/2013] [Indexed: 01/02/2023]
|
14
|
Geter DR, Bhat VS, Gollapudi BB, Sura R, Hester SD. Dose-Response Modeling of Early Molecular and Cellular Key Events in the CAR-Mediated Hepatocarcinogenesis Pathway. Toxicol Sci 2014; 138:425-45. [DOI: 10.1093/toxsci/kfu014] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
|
15
|
Klepeisz P, Sagmeister S, Haudek-Prinz V, Pichlbauer M, Grasl-Kraupp B, Gerner C. Phenobarbital induces alterations in the proteome of hepatocytes and mesenchymal cells of rat livers. PLoS One 2013; 8:e76137. [PMID: 24204595 PMCID: PMC3812042 DOI: 10.1371/journal.pone.0076137] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2013] [Accepted: 08/27/2013] [Indexed: 11/18/2022] Open
Abstract
Preceding studies on the mode of action of non-genotoxic hepatocarcinogens (NGCs) have concentrated on alterations induced in hepatocytes (HCs). A potential role of non-parenchymal liver cells (NPCs) in NGC-driven hepatocarcinogenesis has been largely neglected so far. The aim of this study is to characterize NGC-induced alterations in the proteome profiles of HCs as well as NPCs. We chose the prototypic NGC phenobarbital (PB) which was applied to male rats for a period of 14 days. The livers of PB-treated rats were perfused by collagenase and the cell suspensions obtained were subjected to density gradient centrifugation to separate HCs from NPCs. In addition, HCs and NPC isolated from untreated animals were treated with PB in vitro. Proteome profiling was done by CHIP-HPLC and ion trap mass spectrometry. Proteome analyses of the in vivo experiments showed many of the PB effects previously described in HCs by other methods, e.g. induction of phase I and phase II drug metabolising enzymes. In NPCs proteins related to inflammation and immune regulation such as PAI-1 and S100-A10, ADP-ribosyl cyclase 1 and to cell migration such as kinesin-1 heavy chain, myosin regulatory light chain RLC-A and dihydropyrimidinase-related protein 1 were found to be induced, indicating major PB effects on these cells. Remarkably, in vitro treatment of HCs and NPCs with PB hardly reproduced the proteome alterations observed in vivo, indicating differences of NGC induced responses of cells at culture conditions compared to the intact organism. To conclude, the present study clearly demonstrated that PB induces proteome alterations not only in HCs but also in NPCs. Thus, any profound molecular understanding on the mode of action of NGCs has to consider effects on cells of the hepatic mesenchyme.
Collapse
Affiliation(s)
- Philip Klepeisz
- Department of Inner Medicine I, Comprehensive Cancer Center, Institute of Cancer Research, Medical University of Vienna, Vienna, Austria
| | - Sandra Sagmeister
- Department of Inner Medicine I, Comprehensive Cancer Center, Institute of Cancer Research, Medical University of Vienna, Vienna, Austria
| | - Verena Haudek-Prinz
- Department of Inner Medicine I, Comprehensive Cancer Center, Institute of Cancer Research, Medical University of Vienna, Vienna, Austria
- Institute of Analytical Chemistry, Faculty of Chemistry, University of Vienna, Vienna, Austria
| | - Melanie Pichlbauer
- Department of Inner Medicine I, Comprehensive Cancer Center, Institute of Cancer Research, Medical University of Vienna, Vienna, Austria
| | - Bettina Grasl-Kraupp
- Department of Inner Medicine I, Comprehensive Cancer Center, Institute of Cancer Research, Medical University of Vienna, Vienna, Austria
| | - Christopher Gerner
- Department of Inner Medicine I, Comprehensive Cancer Center, Institute of Cancer Research, Medical University of Vienna, Vienna, Austria
- Institute of Analytical Chemistry, Faculty of Chemistry, University of Vienna, Vienna, Austria
- * E-mail:
| |
Collapse
|
16
|
Thomson JP, Moggs JG, Wolf CR, Meehan RR. Epigenetic profiles as defined signatures of xenobiotic exposure. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2013; 764-765:3-9. [PMID: 24001620 DOI: 10.1016/j.mrgentox.2013.08.007] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Accepted: 08/24/2013] [Indexed: 01/01/2023]
Abstract
With the advent of high resolution sequencing technologies there has been increasing interest in the study of genome-wide epigenetic modification patterns that govern the underlying gene expression events of a particular cell or tissue type. There is now mounting evidence that perturbations to the epigenetic landscape occur during a host of cellular processes including normal proliferation/differentiation and aberrant outcomes such as carcinogenesis. Furthermore, epigenetic perturbations have been associated with exposure to a range of drugs and toxicants, including non-genotoxic carcinogens (NGCs). Although a variety of epigenetic modifications induced by NGCs have been studied previously, recent genome-wide integrated epigenomic and transcriptomic studies reveal for the first time the extent and dynamic nature of the epigenetic perturbations resulting from xenobiotic exposure. The interrogation and integration of one such epigenetic mark, the newly discovered 5-hydroxymethylcytosine (5hmC) modification, reveals that drug treatment associated perturbations of the epigenome can result in unique epigenetic signatures. This review focuses on how recent advances in the field of epigenetics can enhance our mechanistic understanding of xenobiotic exposure and provide novel safety biomarkers.
Collapse
Affiliation(s)
- John P Thomson
- MRC Human Genetics Unit at the Institute of Genetics and Molecular Medicine at the University of Edinburgh, Crewe Road, Edinburgh EH4 2XU, UK
| | - Jonathan G Moggs
- Discovery & Investigative Safety, Investigative Toxicology, Preclinical Safety, Translational Sciences, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - C Roland Wolf
- Medical Research Institute, University of Dundee, Ninewells Hospital & Medical School, Dundee, DD1 9SY, UK
| | - Richard R Meehan
- MRC Human Genetics Unit at the Institute of Genetics and Molecular Medicine at the University of Edinburgh, Crewe Road, Edinburgh EH4 2XU, UK.
| |
Collapse
|
17
|
Sakamoto Y, Inoue K, Takahashi M, Taketa Y, Kodama Y, Nemoto K, Degawa M, Gamou T, Ozawa S, Nishikawa A, Yoshida M. Different Pathways of Constitutive Androstane Receptor–mediated Liver Hypertrophy and Hepatocarcinogenesis in Mice Treated with Piperonyl Butoxide or Decabromodiphenyl Ether. Toxicol Pathol 2013; 41:1078-92. [DOI: 10.1177/0192623313482055] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The constitutive androstane receptor (CAR) is essential for Cyp2b induction, liver hypertrophy, and hepatocarcinogenesis in response to phenobarbital (PB). Liver hypertrophy with Cyp2b induction is a major mode of action of hepatocarcinogenesis in rodents. However, it remains unclear whether CAR is involved in the response to many other nongenotoxic hepatocarcinogens besides PB. In this study, we investigated CAR involvement in liver hypertrophy and hepatocarcinogenesis of Cyp2b-inducing nongenotoxic hepatocarcinogens, piperonyl butoxide (PBO), and decabromodiphenyl ether (DBDE), using wild-type and CAR knockout (CARKO) male mice. PB was used as the positive control. In the wild-type mice, 4-week treatment with PBO, DBDE, or PB induced hepatocellular hypertrophy with increased Cyp2b10 messenger RNA and Cyp2b protein expression. In CARKO mice, only PBO showed liver hypertrophy with Cyp2b10 and Cyp3a11 induction. After 27-week treatment following diethylnitrosamine initiation, PBO and PB generated many eosinophilic altered foci/adenomas in wild-type mice; however, the lesions were far less frequent in CARKO mice. DBDE increased the multiplicity of basophilic altered foci/adenomas in wild-type and CARKO mice. Our findings indicate that murine CAR plays major roles in hepatocarcinogenesis but not in liver hypertrophy of PBO. DBDE may act via CAR-independent pathways during hepatocarcinogenesis.
Collapse
Affiliation(s)
- Yohei Sakamoto
- Division of Pathology, National Institute of Health Sciences, Setagaya-ku, Tokyo, Japan
| | - Kaoru Inoue
- Division of Pathology, National Institute of Health Sciences, Setagaya-ku, Tokyo, Japan
| | - Miwa Takahashi
- Division of Pathology, National Institute of Health Sciences, Setagaya-ku, Tokyo, Japan
| | - Yoshikazu Taketa
- Division of Pathology, National Institute of Health Sciences, Setagaya-ku, Tokyo, Japan
| | - Yukio Kodama
- Division of Cellular and Molecular Toxicology, National Institute of Health Sciences, Setagaya-ku, Tokyo, Japan
| | - Kiyomitsu Nemoto
- Department of Molecular Toxicology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan
| | - Masakuni Degawa
- Department of Molecular Toxicology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan
| | - Toshie Gamou
- Department of Pharmacodynamics Molecular Genetics, School of Pharmacy, Iwate Medical University, Iwate, Japan
| | - Shogo Ozawa
- Department of Pharmacodynamics Molecular Genetics, School of Pharmacy, Iwate Medical University, Iwate, Japan
| | - Akiyoshi Nishikawa
- Biological Safety Center, National Institute of Health Sciences, Tokyo, Japan
| | - Midori Yoshida
- Division of Pathology, National Institute of Health Sciences, Setagaya-ku, Tokyo, Japan
| |
Collapse
|
18
|
Pogribny IP, Rusyn I. Environmental toxicants, epigenetics, and cancer. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 754:215-32. [PMID: 22956504 PMCID: PMC4281087 DOI: 10.1007/978-1-4419-9967-2_11] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Tumorigenesis, a complex and multifactorial progressive process of transformation of normal cells into malignant cells, is characterized by the accumulation of multiple cancer-specific heritable phenotypes triggered by the mutational and/or non-mutational (i.e., epigenetic) events. Accumulating evidence suggests that environmental and occupational exposures to natural substances, as well as man-made chemical and physical agents, play a causative role in human cancer. In a broad sense, carcinogenesis may be induced through either genotoxic or non-genotoxic mechanisms; however, both genotoxic and non-genotoxic carcinogens also cause prominent epigenetic changes. This review presents current evidence of the epigenetic alterations induced by various chemical carcinogens, including arsenic, 1,3-butadine, and pharmaceutical and biological agents, and highlights the potential for epigenetic changes to serve as markers for carcinogen exposure and cancer risk assessment.
Collapse
Affiliation(s)
- Igor P. Pogribny
- Division of Biochemical Toxicology, National Center for Toxicological Research, Jefferson, AR 72079, USA
| | - Ivan Rusyn
- Department of Environmental Sciences & Engineering, University of North Carolina, Chapel Hill, NC 27599, USA
| |
Collapse
|
19
|
Cerminara C, Bagnolo V, De Leonardis F, Coniglio A, Roberto D, Compagnone E, Curatolo P. Hepatocellular adenoma associated with long-term exposure to phenobarbital: a paediatric case report. Childs Nerv Syst 2012; 28:939-41. [PMID: 22124572 DOI: 10.1007/s00381-011-1636-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2011] [Accepted: 11/17/2011] [Indexed: 12/18/2022]
Affiliation(s)
- Caterina Cerminara
- Unit of Child Neurology and Psychiatry, Department of Neuroscience, University of Rome Tor Vergata, Viale Oxford 81, Rome, Italy.
| | | | | | | | | | | | | |
Collapse
|
20
|
|
21
|
Lempiäinen H, Müller A, Brasa S, Teo SS, Roloff TC, Morawiec L, Zamurovic N, Vicart A, Funhoff E, Couttet P, Schübeler D, Grenet O, Marlowe J, Moggs J, Terranova R. Phenobarbital mediates an epigenetic switch at the constitutive androstane receptor (CAR) target gene Cyp2b10 in the liver of B6C3F1 mice. PLoS One 2011; 6:e18216. [PMID: 21455306 PMCID: PMC3063791 DOI: 10.1371/journal.pone.0018216] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2010] [Accepted: 02/28/2011] [Indexed: 11/19/2022] Open
Abstract
Evidence suggests that epigenetic perturbations are involved in the adverse effects associated with some drugs and toxicants, including certain classes of non-genotoxic carcinogens. Such epigenetic changes (altered DNA methylation and covalent histone modifications) may take place at the earliest stages of carcinogenesis and their identification holds great promise for biomedical research. Here, we evaluate the sensitivity and specificity of genome-wide epigenomic and transcriptomic profiling in phenobarbital (PB)-treated B6C3F1 mice, a well-characterized rodent model of non-genotoxic liver carcinogenesis. Methylated DNA Immunoprecipitation (MeDIP)-coupled microarray profiling of 17,967 promoter regions and 4,566 intergenic CpG islands was combined with genome-wide mRNA expression profiling to identify liver tissue-specific PB-mediated DNA methylation and transcriptional alterations. Only a limited number of significant anti-correlations were observed between PB-induced transcriptional and promoter-based DNA methylation perturbations. However, the constitutive androstane receptor (CAR) target gene Cyp2b10 was found to be concomitantly hypomethylated and transcriptionally activated in a liver tissue-specific manner following PB treatment. Furthermore, analysis of active and repressive histone modifications using chromatin immunoprecipitation revealed a strong PB-mediated epigenetic switch at the Cyp2b10 promoter. Our data reveal that PB-induced transcriptional perturbations are not generally associated with broad changes in the DNA methylation status at proximal promoters and suggest that the drug-inducible CAR pathway regulates an epigenetic switch from repressive to active chromatin at the target gene Cyp2b10. This study demonstrates the utility of integrated epigenomic and transcriptomic profiling for elucidating early mechanisms and biomarkers of non-genotoxic carcinogenesis.
Collapse
Affiliation(s)
- Harri Lempiäinen
- Investigative Toxicology, Preclinical Safety, Translational Sciences, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Arne Müller
- Investigative Toxicology, Preclinical Safety, Translational Sciences, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Sarah Brasa
- Investigative Toxicology, Preclinical Safety, Translational Sciences, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Soon-Siong Teo
- Investigative Toxicology, Preclinical Safety, Translational Sciences, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | | | - Laurent Morawiec
- Investigative Toxicology, Preclinical Safety, Translational Sciences, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Natasa Zamurovic
- Investigative Toxicology, Preclinical Safety, Translational Sciences, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Axel Vicart
- Investigative Toxicology, Preclinical Safety, Translational Sciences, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Enrico Funhoff
- Investigative Toxicology, Preclinical Safety, Translational Sciences, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Philippe Couttet
- Investigative Toxicology, Preclinical Safety, Translational Sciences, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Dirk Schübeler
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Olivier Grenet
- Investigative Toxicology, Preclinical Safety, Translational Sciences, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Jennifer Marlowe
- Investigative Toxicology, Preclinical Safety, Translational Sciences, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Jonathan Moggs
- Investigative Toxicology, Preclinical Safety, Translational Sciences, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Rémi Terranova
- Investigative Toxicology, Preclinical Safety, Translational Sciences, Novartis Institutes for Biomedical Research, Basel, Switzerland
- * E-mail:
| |
Collapse
|
22
|
Chen T, Mally A, Ozden S, Chipman JK. Low doses of the carcinogen furan alter cell cycle and apoptosis gene expression in rat liver independent of DNA methylation. ENVIRONMENTAL HEALTH PERSPECTIVES 2010; 118:1597-602. [PMID: 20562052 PMCID: PMC2974699 DOI: 10.1289/ehp.1002153] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2010] [Revised: 05/13/2010] [Accepted: 06/18/2010] [Indexed: 05/25/2023]
Abstract
BACKGROUND Evidence of potent rodent carcinogenicity via an unclear mechanism suggests that furan in various foods [leading to an intake of up to 3.5 microg/kg body weight (bw)/day] may present a potential risk to human health. OBJECTIVES We tested the hypothesis that altered expression of genes related to cell cycle control, apoptosis, and DNA damage may contribute to the carcinogenicity of furan in rodents. In addition, we investigated the reversibility of such changes and the potential role of epigenetic mechanisms in response to furan doses that approach the maximum estimated dietary intake in humans. METHODS The mRNA expression profiles of genes related to cell cycle, apoptosis, and DNA damage in rat liver treated with furan concentrations of 0.1 and 2 mg/kg bw were measured by quantitative polymerase chain reaction (PCR) arrays. We assessed epigenetic changes by analysis of global and gene-specific DNA methylation [methylation-specific PCR, combined bisulfite restriction analysis (COBRA), and methylated DNA immunoprecipitation chip] and microRNA (miRNA) analyses. RESULTS The expression profiles of apoptosis-related and cell-cycle-related genes were unchanged after 5 days of treatment, although we observed a statistically significant change in the expression of genes related to cell cycle control and apoptosis, but not DNA damage, after 4 weeks of treatment. These changes were reversed after an off-dose period of 2 weeks. None of the gene expression changes was associated with a change in DNA methylation, although we detected minor changes in the miRNA expression profile (5 miRNA alterations out of 349 measured) that may have contributed to modification of gene expression in some cases. CONCLUSION Nongenotoxic changes in gene expression may contribute to the carcinogenicity of furan in rodents. These findings highlight the need for a more comprehensive risk assessment of furan exposure in humans.
Collapse
Affiliation(s)
- Tao Chen
- School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Angela Mally
- Department of Toxicology, University of Würzburg, Würzburg, Germany
| | - Sibel Ozden
- Department of Toxicology, University of Würzburg, Würzburg, Germany
- Department of Pharmaceutical Toxicology, Istanbul University, Istanbul, Turkey
| | - J. Kevin Chipman
- School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| |
Collapse
|
23
|
Kay HY, Wu H, Lee SI, Kim SG. Applications of genetically modified tools to safety assessment in drug development. Toxicol Res 2010; 26:1-8. [PMID: 24278499 PMCID: PMC3834461 DOI: 10.5487/tr.2010.26.1.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2010] [Revised: 01/26/2010] [Accepted: 01/26/2010] [Indexed: 02/01/2023] Open
Abstract
The process of new drug development consists of several stages; after identifying potential candidate compounds, preclinical studies using animal models link the laboratory and human clinical trials. Among many steps in preclinical studies, toxicology and safety assessments contribute to identify potential adverse events and provide rationale for setting the initial doses in clinical trials. Gene modulation is one of the important tools of modern biology, and is commonly employed to examine the function of genes of interest. Advances in new drug development have been achieved by exploding information on target selection and validation using genetically modified animal models as well as those of cells. In this review, a recent trend of genetically modified methods is discussed with reference to safety assessments, and the exemplary applications of gene-modulating tools to the tests in new drug development were summarized.
Collapse
Affiliation(s)
- Hee Yeon Kay
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University
| | | | | | | |
Collapse
|
24
|
Phillips JM, Burgoon LD, Goodman JI. The constitutive active/androstane receptor facilitates unique phenobarbital-induced expression changes of genes involved in key pathways in precancerous liver and liver tumors. Toxicol Sci 2009; 110:319-33. [PMID: 19482888 DOI: 10.1093/toxsci/kfp108] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Our overall goal is to elucidate progressive changes, in expression and methylation status, of genes which play key roles in phenobarbital (PB)-induced liver tumorigenesis, with an emphasis on their potential to affect signaling through critical pathways involved in the regulation of cell growth and differentiation. PB-elicited unique expression changes of genes, including some of those identified previously as exhibiting regions of altered DNA methylation, were discerned in precancerous liver tissue and/or individual liver tumors from susceptible constitutive active/androstane receptor (CAR) wild-type (WT) compared with resistant CAR knockout (KO) mice. Many of these function in crucial cancer-related processes, for example, angiogenesis, apoptosis, cell cycle, DNA methylation, Hedgehog signaling, invasion/metastasis, Notch signaling, and Wnt signaling. Furthermore, a subset of the uniquely altered genes contained CAR response elements (CAREs). This included Gadd45b, a coactivator of CAR and inhibitor of apoptosis, and two DNA methyltransferases (Dnmt1, Dnmt3a). The presence of CAREs in Dnmts suggests a potential direct link between PB and altered DNA methylation. The current data are juxtaposed with the effects of PB on DNA methylation and gene expression which occurred uniquely in liver tumor-prone B6C3F1 mice, as compared with the resistant C57BL/6, following 2 or 4 weeks of treatment. Collectively, these data reveal a comprehensive view of PB-elicited molecular alterations (i.e., changes in gene expression and DNA methylation) that can facilitate hepatocarcinogenesis. Notably, candidate genes for initial "fingerprints" of early and late stages of PB-induced tumorigenesis are proposed.
Collapse
Affiliation(s)
- Jennifer M Phillips
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, USA
| | | | | |
Collapse
|
25
|
Phillips JM, Burgoon LD, Goodman JI. Phenobarbital elicits unique, early changes in the expression of hepatic genes that affect critical pathways in tumor-prone B6C3F1 mice. Toxicol Sci 2009; 109:193-205. [PMID: 19270015 DOI: 10.1093/toxsci/kfp050] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
At 2 and 4 weeks following treatment with phenobarbital (PB), the classical nongenotoxic rodent liver carcinogen, we elucidated unique gene expression changes (both induction and repression) in liver tumor-susceptible B6C3F1 mice, as compared with the relatively resistant C57BL/6. Based on their cancer-related roles, we believe that altered expression of at least some of these genes might underlie PB-induced liver tumorigenesis. Putative constitutive active/androstane (CAR) response elements (CAREs), a subset of PB response elements, were present within multiple genes whose expression was uniquely altered in the B6C3F1 mice, suggesting a role for CAR in their regulation. Additionally, three DNA methyltransferase genes (Dnmt1, Dnmt3a, and Dnmt3b) were repressed uniquely in the tumor-prone B6C3F1 mice, and all possess putative CAREs, providing a potential direct link between PB and expression of key genes that regulate DNA methylation status. Previously, we demonstrated that PB-elicited unique regions of altered methylation (RAMs) in B6C3F1 mice, as compared with the relatively resistant C57BL/6, at 2 and 4 weeks, and annotation of the regions harboring these changes revealed 51 genes. This is extended by the current study, which employed RNA isolated from the same liver tissue used in the earlier investigations. Genes elucidated from both the methylation and expression analyses are involved in identical processes/pathways (e.g., cell cycle, apoptosis, angiogenesis, epithelial-mesenchymal cell transition, invasion/metastasis, and mitogen-activated protein kinase, transforming growth factor-beta, and Wnt signaling). Therefore, these changes might represent very early events that directly contribute to PB-induced tumorigenesis. It is instructive to consider the possibility that, in a hypothesis-driven fashion, these genes are initial candidates that could be utilized to develop a biomarker "fingerprint" of early exposure to PB and PB-like compounds.
Collapse
Affiliation(s)
- Jennifer M Phillips
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, USA
| | | | | |
Collapse
|