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Boycott C, Beetch M, Yang T, Lubecka K, Ma Y, Zhang J, Kurzava Kendall L, Ullmer M, Ramsey BS, Torregrosa-Allen S, Elzey BD, Cox A, Lanman NA, Hui A, Villanueva N, de Conti A, Huan T, Pogribny I, Stefanska B. Epigenetic aberrations of gene expression in a rat model of hepatocellular carcinoma. Epigenetics 2022; 17:1513-1534. [PMID: 35502615 PMCID: PMC9586690 DOI: 10.1080/15592294.2022.2069386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 03/22/2022] [Accepted: 04/14/2022] [Indexed: 11/15/2022] Open
Abstract
Hepatocellular carcinoma (HCC) is mostly triggered by environmental and life-style factors and may involve epigenetic aberrations. However, a comprehensive documentation of the link between the dysregulated epigenome, transcriptome, and liver carcinogenesis is lacking. In the present study, Fischer-344 rats were fed a choline-deficient (CDAA, cancer group) or choline-sufficient (CSAA, healthy group) L-amino acid-defined diet. At the end of 52 weeks, transcriptomic alterations in livers of rats with HCC tumours and healthy livers were investigated by RNA sequencing. DNA methylation and gene expression were assessed by pyrosequencing and quantitative reverse-transcription PCR (qRT-PCR), respectively. We discovered 1,848 genes that were significantly differentially expressed in livers of rats with HCC tumours (CDAA) as compared with healthy livers (CSAA). Upregulated genes in the CDAA group were associated with cancer-related functions, whereas macronutrient metabolic processes were enriched by downregulated genes. Changes of highest magnitude were detected in numerous upregulated genes that govern key oncogenic signalling pathways, including Notch, Wnt, Hedgehog, and extracellular matrix degradation. We further detected perturbations in DNA methylating and demethylating enzymes, which was reflected in decreased global DNA methylation and increased global DNA hydroxymethylation. Four selected upregulated candidates, Mmp12, Jag1, Wnt4, and Smo, demonstrated promoter hypomethylation with the most profound decrease in Mmp12. MMP12 was also strongly overexpressed and hypomethylated in human HCC HepG2 cells as compared with primary hepatocytes, which coincided with binding of Ten-eleven translocation 1 (TET1). Our findings provide comprehensive evidence for gene expression changes and dysregulated epigenome in HCC pathogenesis, potentially revealing novel targets for HCC prevention/treatment.
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Affiliation(s)
- Cayla Boycott
- Food, Nutrition and Health Program, Faculty of Land and Food Systems, University of British Columbia, Vancouver, British Columbia, Canada
| | - Megan Beetch
- Food, Nutrition and Health Program, Faculty of Land and Food Systems, University of British Columbia, Vancouver, British Columbia, Canada
| | - Tony Yang
- Food, Nutrition and Health Program, Faculty of Land and Food Systems, University of British Columbia, Vancouver, British Columbia, Canada
| | - Katarzyna Lubecka
- Department of Biomedical Chemistry, Faculty of Health Sciences, Medical University of Lodz, Lodz, Poland
| | - Yuexi Ma
- Food, Nutrition and Health Program, Faculty of Land and Food Systems, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jiaxi Zhang
- Food, Nutrition and Health Program, Faculty of Land and Food Systems, University of British Columbia, Vancouver, British Columbia, Canada
| | - Lucinda Kurzava Kendall
- Department of Nutrition Science, College of Health and Human Sciences, Purdue University, Indiana, USA
- Department of Internal Medicine, Ascension St. Vincent Hospital, Indianapolis, Indiana, USA
| | - Melissa Ullmer
- Department of Anatomy, Cell Biology and Physiology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Benjamin S. Ramsey
- Purdue University Center for Cancer Research, Purdue University, West Lafayette, Indiana, USA
| | - Sandra Torregrosa-Allen
- Purdue University Center for Cancer Research, Purdue University, West Lafayette, Indiana, USA
| | - Bennett D. Elzey
- Purdue University Center for Cancer Research, Purdue University, West Lafayette, Indiana, USA
- Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, Indiana, USA
| | - Abigail Cox
- Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, Indiana, USA
| | - Nadia Atallah Lanman
- Purdue University Center for Cancer Research, Purdue University, West Lafayette, Indiana, USA
- Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, Indiana, USA
| | - Alisa Hui
- Department of Chemistry, Faculty of Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Nathaniel Villanueva
- Department of Chemistry, Faculty of Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Aline de Conti
- Division of Biochemical Toxicology, FDA-National Center for Toxicological Research, Jefferson, Arkansas, USA
| | - Tao Huan
- Department of Chemistry, Faculty of Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Igor Pogribny
- Division of Biochemical Toxicology, FDA-National Center for Toxicological Research, Jefferson, Arkansas, USA
| | - Barbara Stefanska
- Food, Nutrition and Health Program, Faculty of Land and Food Systems, University of British Columbia, Vancouver, British Columbia, Canada
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Zweerink S, Mueck V, Kraemer LP, Tischler E, Schulte S, Goeser T, Nierhoff D. Repolarization Precedes Oval Cell-mediated Hepatocytic Regeneration in the CDE Diet Mouse Model. J Histochem Cytochem 2022; 70:377-389. [PMID: 35272516 PMCID: PMC9058371 DOI: 10.1369/00221554221084665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The liver has a unique ability to recover from injury unlike any other organ. A poorly understood aspect of liver regeneration is the role of hepatocellular polarization. Neighbor of Punc E11 (Nope) is an oncofetal stem/progenitor cell marker, which is expressed by depolarized adult hepatocytes after cholestatic liver injury and in hepatocellular carcinoma. Liver injury induced by a choline-deficient and ethionine-supplemented diet is reversible if followed by an additional dietary stop interval and enabled us to study the expression of Nope during the induction of chronic liver injury and during subsequent liver regeneration. We could show by quantitative RT-PCR, Western blotting, and immunohistochemistry that the expression of Nope is induced in depolarized adult hepatocytes during injury. However, after another 2 weeks of a normal diet, the polarization of hepatocytes was almost completely restored and the expression of Nope remained limited to bile ducts and oval cells. Using an inducible CK19-lineage tracing model, we could demonstrate that oval cell-mediated hepatocyte regeneration is rare and was preceded by repolarization of hepatocytes. In conclusion, polarization of hepatocytes is an important part of liver regeneration and precedes oval cell-mediated regeneration of the liver. This process can be visualized by a characteristic expression pattern of Nope.
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Affiliation(s)
- Susanne Zweerink
- Department of Gastroenterology and Hepatology, Faculty of Medicine and University Hospital of Cologne, University of Cologne, Cologne, Germany
| | - Vera Mueck
- Department of Gastroenterology and Hepatology, Faculty of Medicine and University Hospital of Cologne, University of Cologne, Cologne, Germany
| | - Laurenz P Kraemer
- Department of Gastroenterology and Hepatology, Faculty of Medicine and University Hospital of Cologne, University of Cologne, Cologne, Germany
| | - Eva Tischler
- Department of Gynecology and Obstetrics, University Tuebingen, 72076 Tuebingen, Germany (ET)
| | - Sigrid Schulte
- Department of Gastroenterology and Hepatology, Faculty of Medicine and University Hospital of Cologne, University of Cologne, Cologne, Germany
| | - Tobias Goeser
- Department of Gastroenterology and Hepatology, Faculty of Medicine and University Hospital of Cologne, University of Cologne, Cologne, Germany
| | - Dirk Nierhoff
- Department of Gastroenterology and Hepatology, Faculty of Medicine and University Hospital of Cologne, University of Cologne, Cologne, Germany
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Liu ZY, Zhang DM, Yishake D, Luo Y, Fang AP, Zhu HL. Dietary choline, rather than betaine intake, is associated with hepatocellular carcinoma mortality. Food Funct 2020; 11:7866-7877. [PMID: 32812611 DOI: 10.1039/d0fo01890b] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The dietary intakes of choline and betaine have been related to the mortality of some neoplasms, but their effects on hepatocellular carcinoma (HCC) mortality are still unknown. We examined the associations between dietary choline, five choline-containing compounds, different choline forms, betaine intake and HCC mortality. In total, 905 newly diagnosed HCC patients were enrolled in the Guangdong Liver Cancer Cohort study. Dietary intake was assessed by a valid food frequency questionnaire. Liver cancer-specific mortality (LCSM) and all-cause mortality (ACM) were calculated. Hazard ratios (HRs) and 95% confidence intervals (CIs) were computed by Cox proportional hazards models. It was found that a higher total choline intake was associated with lower ACM, Q4 vs. Q1: HR = 0.72, 95% CI: 0.53-0.97, Ptrend = 0.012 in the fully adjusted model. The associations between total choline intake and LCSM were not significant. Similar associations were found between water-soluble choline intake and HCC mortality, where the fully adjusted HR for ACM was 0.72, 95% CI: 0.53-0.98, Ptrend = 0.017. However, null associations were found between neither phosphatidylcholine (the most abundant lipid-soluble choline) nor total lipid-soluble choline intake and HCC mortality. These results implied that the favorable associations between the total choline intake and ACM were more attributed to water-soluble choline. Furthermore, no significant associations were observed between betaine intake and HCC mortality. Future human intervention trials regarding choline supplementation and liver disease recovery should take the forms into consideration rather than just the total amount alone.
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Affiliation(s)
- Zhao-Yan Liu
- Guangdong Provincial Key Laboratory of Food, Nutrition and Health, School of Public Health, Sun Yat-sen University, Guangzhou 510080, People's Republic of China.
| | - Dao-Ming Zhang
- Guangdong Provincial Key Laboratory of Food, Nutrition and Health, School of Public Health, Sun Yat-sen University, Guangzhou 510080, People's Republic of China.
| | - Dinuerguli Yishake
- Guangdong Provincial Key Laboratory of Food, Nutrition and Health, School of Public Health, Sun Yat-sen University, Guangzhou 510080, People's Republic of China.
| | - Yun Luo
- Guangdong Provincial Key Laboratory of Food, Nutrition and Health, School of Public Health, Sun Yat-sen University, Guangzhou 510080, People's Republic of China.
| | - Ai-Ping Fang
- Guangdong Provincial Key Laboratory of Food, Nutrition and Health, School of Public Health, Sun Yat-sen University, Guangzhou 510080, People's Republic of China.
| | - Hui-Lian Zhu
- Guangdong Provincial Key Laboratory of Food, Nutrition and Health, School of Public Health, Sun Yat-sen University, Guangzhou 510080, People's Republic of China.
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Leroy K, Pieters A, Tabernilla A, Cooreman A, Van Campenhout R, Cogliati B, Vinken M. Targeting gap junctional intercellular communication by hepatocarcinogenic compounds. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART B, CRITICAL REVIEWS 2020; 23:255-275. [PMID: 32568623 DOI: 10.1080/10937404.2020.1781010] [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] [Indexed: 06/11/2023]
Abstract
Gap junctions in liver, as in other organs, play a critical role in tissue homeostasis. Inherently, these cellular constituents are major targets for systemic toxicity and diseases, including cancer. This review provides an overview of chemicals that compromise liver gap junctions, in particular biological toxins, organic solvents, pesticides, pharmaceuticals, peroxides, metals and phthalates. The focus in this review is placed upon the mechanistic scenarios that underlie these adverse effects. Further, the potential use of gap junctional activity as an in vitro biomarker to identify non-genotoxic hepatocarcinogenic chemicals is discussed.
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Affiliation(s)
- Kaat Leroy
- Department of In Vitro Toxicology and Dermato-Cosmetology, Vrije Universiteit Brussel , Brussels, Belgium
| | - Alanah Pieters
- Department of In Vitro Toxicology and Dermato-Cosmetology, Vrije Universiteit Brussel , Brussels, Belgium
| | - Andrés Tabernilla
- Department of In Vitro Toxicology and Dermato-Cosmetology, Vrije Universiteit Brussel , Brussels, Belgium
| | - Axelle Cooreman
- Department of In Vitro Toxicology and Dermato-Cosmetology, Vrije Universiteit Brussel , Brussels, Belgium
| | - Raf Van Campenhout
- Department of In Vitro Toxicology and Dermato-Cosmetology, Vrije Universiteit Brussel , Brussels, Belgium
| | - Bruno Cogliati
- Department of Pathology, School of Veterinary Medicine and Animal Science, University of São Paulo, Cidade Universitária , São Paulo, Brazil
| | - Mathieu Vinken
- Department of In Vitro Toxicology and Dermato-Cosmetology, Vrije Universiteit Brussel , Brussels, Belgium
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Methylation Dynamics of RASSF1A and Its Impact on Cancer. Cancers (Basel) 2019; 11:cancers11070959. [PMID: 31323949 PMCID: PMC6678546 DOI: 10.3390/cancers11070959] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 07/03/2019] [Accepted: 07/08/2019] [Indexed: 01/15/2023] Open
Abstract
5-methyl cytosine (5mC) is a key epigenetic mark entwined with gene expression and the specification of cellular phenotypes. Its distribution around gene promoters sets a barrier for transcriptional enhancers or inhibitor proteins binding to their target sequences. As a result, an additional level of regulation is added to the signals that organize the access to the chromatin and its structural components. The tumor suppressor gene RASSF1A is a microtubule-associated and multitasking scaffold protein communicating with the RAS pathway, estrogen receptor signaling, and Hippo pathway. RASSF1A action stimulates mitotic arrest, DNA repair and apoptosis, and controls the cell cycle and cell migration. De novo methylation of the RASSF1A promoter has received much attention due to its increased frequency in most cancer types. RASSF1A methylation is preceded by histones modifications and could represent an early molecular event in cell transformation. Accordingly, RASSF1A methylation is proposed as an epigenetic candidate marker in many cancer types, even though an inverse correlation of methylation and expression remains to be fully ascertained. Some findings indicate that the epigenetic abrogation of RASSF1A can promote the alternative expression of the putative oncogenic isoform RASSF1C. Understanding the complexity and significance of RASSF1A methylation is instrumental for a more accurate determination of its biological and clinical role. The review covers the molecular events implicated in RASSF1A methylation and gene silencing and provides a deeper view into the significance of the RASSF1A methylation patterns in a number of gastrointestinal cancer types.
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Hernández-Guerra M, Hadjihambi A, Jalan R. Gap junctions in liver disease: Implications for pathogenesis and therapy. J Hepatol 2019; 70:759-772. [PMID: 30599172 DOI: 10.1016/j.jhep.2018.12.023] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2018] [Revised: 12/03/2018] [Accepted: 12/12/2018] [Indexed: 02/07/2023]
Abstract
In the normal liver, cells interact closely through gap junctions. By providing a pathway for the trafficking of low molecular mass molecules, these channels contribute to tissue homeostasis and maintenance of hepatic function. Thus, dysfunction of gap junctions affects a wide variety of liver processes, such as differentiation, cell death, inflammation and fibrosis. In fact, dysfunctional gap junctions have been implicated, for more than a decade, in cholestatic disease, hepatic cancer and cirrhosis. Additionally, in recent years there is an increasing body of evidence that these channels are also involved in other relevant and prevalent liver pathological processes, such as non-alcoholic fatty liver disease, acute liver injury and portal hypertension. In parallel to these new clinical implications the available data include controversial observations. Thus, a comprehensive overview is required to better understand the functional complexity of these pores. This paper will review the most recent knowledge concerning gap junction dysfunction, with a special focus on the role of these channels in the pathogenesis of relevant clinical entities and on potential therapeutic targets that are amenable to modification by drugs.
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Affiliation(s)
| | | | - Rajiv Jalan
- UCL Institute for Liver and Digestive Health, Royal Free Medical School, London, UK
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Bowe A, Zweerink S, Mück V, Kondylis V, Schulte S, Goeser T, Nierhoff D. Depolarized Hepatocytes Express the Stem/Progenitor Cell Marker Neighbor of Punc E11 After Bile Duct Ligation in Mice. J Histochem Cytochem 2018; 66:563-576. [PMID: 29624127 DOI: 10.1369/0022155418768230] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
There is a medical need of biomarkers for disease stratification in cholestatic liver diseases that come along with changes in hepatocyte polarity. Neighbor of Punc E11 (Nope) is an oncofetal marker that is lost after final differentiation and polarization of hepatocytes. We analyzed the expression pattern of Nope and connexin (Cx) 26 as markers of hepatocyte polarization during murine liver development as well as in adult liver with or without bile duct ligation (BDL) by quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR), western blotting (WB), and immunohistochemistry. Nope is highly expressed in fetal and postnatal liver but barely detectable thereafter. Cx26, however, is much higher expressed in adult than in fetal liver. Postnatally, Nope is directed to the sinusoidal membrane of early hepatocytes while Cx26 remains distributed over the whole membrane indicating limited polarization. In the adult liver, only Cx26 is detectable and restricted to the bile canalicular domain indicating fully polarized hepatocytes. After BDL, Nope is again >300-fold upregulated while Cx26 is reduced rapidly. By immunohistochemistry, Nope identifies a subset of hepatocytes with randomly distributed Cx26. In summary, Nope identifies depolarized adult hepatocytes after cholestatic liver injury resembling early postnatal hepatocytes. Therefore, Nope might be a valuable histochemical biomarker allowing stage-specific stratifications in cholestatic liver diseases.
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Affiliation(s)
- Andrea Bowe
- Department of Gastroenterology and Hepatology, University Hospital of Cologne, Cologne, Germany
| | - Susanne Zweerink
- Department of Gastroenterology and Hepatology, University Hospital of Cologne, Cologne, Germany
| | - Vera Mück
- Department of Gastroenterology and Hepatology, University Hospital of Cologne, Cologne, Germany
| | - Vangelis Kondylis
- Institute for Genetics, Centre for Molecular Medicine, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, Cologne, Germany
| | - Sigrid Schulte
- Department of Gastroenterology and Hepatology, University Hospital of Cologne, Cologne, Germany
| | - Tobias Goeser
- Department of Gastroenterology and Hepatology, University Hospital of Cologne, Cologne, Germany
| | - Dirk Nierhoff
- Department of Gastroenterology and Hepatology, University Hospital of Cologne, Cologne, Germany
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Hoffman RM. Is DNA methylation the new guardian of the genome? Mol Cytogenet 2017; 10:11. [PMID: 28396696 PMCID: PMC5381125 DOI: 10.1186/s13039-017-0314-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2017] [Accepted: 03/28/2017] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND It has been known for more than 100 years that aneuploidy is an essence of cancer. The question is what keeps the genome stable, thereby preventing aneuploidy. For the past 25 years, it has been proposed that p53 is the "guardian of the genome." However, it has been shown that inactivation of p53 does not cause aneuploidy. Another essence of cancer is global DNA hypomethylation, which causes destabilization of the genome and subsequent aneupoloidy. Yet, another essence of cancer is excessive use of methionine, resulting in methionine dependence. Methionine dependence is due to possible "metabolic reprogramming" due to carcinogens, including chemical agents and infectious organisms, such as Helicobacter pylori, that result in altered and excessive transmethylation in cancer cells. Cancer cells appear to have a "methyl-sink" whereby methyl groups are diverted from DNA. CONCLUSION DNA hypomethylation destabilizes the genome, leading to aneuploidy and subsequent selection and speciation into autonomous cancers, leading to the conclusion that DNA methylation is the "guardian of the genome."
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Affiliation(s)
- Robert M. Hoffman
- Anti Cancer Inc, 7917 Ostrow Street, San Diego, 92111 CA USA
- Department of Surgery, University of California, San Diego, CA USA
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Abstract
We propose here a hypothesis of the cause of cancer that brings together fundamental changes in methyl-group metabolism resulting in methionine dependence and global DNA hypomethylation which destabilizes the genome leading to aneuploid karyotypes which evolve and stabilize into autonomous cancer. Experimental support for this hypothesis is that methioine dependence is a general metabolic defect in caner. Methionine dependence is due to excess use of methionene for aberrant transmethylation reactions that apparently divert methyl groups from DNA. The resulting global DNA hypomethylation is also a general phenomena in cancer. Global hypomethylation leads to an unstable genomes and aneuploid karyotypes, another general phenomena in cancer. The excessive and aberrant use of methionine in cancer is strongly observed in [11C]methionine PET imaging, where high uptake of [11C]methionine results in a very strong and selective tumor signal compared with normal tissue background. [11C]methionine is superior to [18C] fluorodeoxyglucose (FDG)-PET for PET imaging, suggesting methionine dependence is more tumor-specific than glucose dependence.
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Affiliation(s)
- Robert M Hoffman
- a AntiCancer Inc. , San Diego , CA , USA.,b Department of Surgery , University of California , San Diego , CA , USA
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Kishida N, Matsuda S, Itano O, Shinoda M, Kitago M, Yagi H, Abe Y, Hibi T, Masugi Y, Aiura K, Sakamoto M, Kitagawa Y. Development of a novel mouse model of hepatocellular carcinoma with nonalcoholic steatohepatitis using a high-fat, choline-deficient diet and intraperitoneal injection of diethylnitrosamine. BMC Gastroenterol 2016; 16:61. [PMID: 27296438 PMCID: PMC4906823 DOI: 10.1186/s12876-016-0477-5] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 06/01/2016] [Indexed: 01/19/2023] Open
Abstract
Background The incidence of hepatocellular carcinoma with nonalcoholic steatohepatitis is increasing, and its clinicopathological features are well established. Several animal models of nonalcoholic steatohepatitis have been developed to facilitate its study; however, few fully recapitulate all its clinical features, which include insulin resistance, inflammation, fibrosis, and carcinogenesis. Moreover, these models require a relatively long time to produce hepatocellular carcinoma reliably. The aim of this study was to develop a mouse model of hepatocellular carcinoma with nonalcoholic steatohepatitis that develops quickly and reflects all clinically relevant features. Methods Three-week-old C57BL/6J male mice were fed either a standard diet (MF) or a choline-deficient, high-fat diet (HFCD). The mice in the MF + diethylnitrosamine (DEN) and HFCD + DEN groups received a one-time intraperitoneal injection of DEN at the start of the respective feeding protocols. Results The mice in the HFCD and HFCD + DEN groups developed obesity early in the experiment and insulin resistance after 12 weeks. Triglyceride levels peaked at 8 weeks for all four groups and decreased thereafter. Alanine aminotransferase levels increased every 4 weeks, with the HFCD and HFCD + DEN groups showing remarkably high levels; the HFCD + DEN group presented the highest incidence of nonalcoholic steatohepatitis. The levels of fibrosis and steatosis varied, but they tended to increase every 4 weeks in the HFCD and HFCD + DEN groups. Computed tomography scans indicated that all the HFCD + DEN mice developed hepatic tumors from 20 weeks, some of which were glutamine synthetase-positive. Conclusions The nonalcoholic steatohepatitis-hepatocellular carcinoma model we describe here is simple to establish, results in rapid tumor formation, and recapitulates most of the key features of nonalcoholic steatohepatitis. It could therefore facilitate further studies of the development, oncogenic potential, diagnosis, and treatment of this condition. Electronic supplementary material The online version of this article (doi:10.1186/s12876-016-0477-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Norihiro Kishida
- Department of Surgery, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Sachiko Matsuda
- Department of Surgery, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan.,Chugai Pharmaceutical Endowed Research Chair in Molecular Targeted Therapy of Gastrointestinal Cancer, School of Medicine, Keio University, Tokyo, Japan
| | - Osamu Itano
- Department of Surgery, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan.
| | - Masahiro Shinoda
- Department of Surgery, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Minoru Kitago
- Department of Surgery, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Hiroshi Yagi
- Department of Surgery, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Yuta Abe
- Department of Surgery, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Taizo Hibi
- Department of Surgery, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Yohei Masugi
- Department of Pathology, School of Medicine, Keio University, Tokyo, Japan
| | - Koichi Aiura
- Department of Surgery, Kawasaki Municipal Hospital, Kawasaki-ku, Japan
| | - Michiie Sakamoto
- Department of Pathology, School of Medicine, Keio University, Tokyo, Japan
| | - Yuko Kitagawa
- Department of Surgery, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
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Crespo Yanguas S, Willebrords J, Maes M, da Silva TC, Veloso Alves Pereira I, Cogliati B, Zaidan Dagli ML, Vinken M. Connexins and pannexins in liver damage. EXCLI JOURNAL 2016; 15:177-86. [PMID: 27065778 PMCID: PMC4822047 DOI: 10.17179/excli2016-119] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Accepted: 02/15/2016] [Indexed: 12/19/2022]
Abstract
Connexins and pannexins are key players in the control of cellular communication and thus in the maintenance of tissue homeostasis. Inherent to this function these proteins are frequently involved in pathological processes. The present paper reviews the role of connexins and pannexins in liver toxicity and disease. As they act both as sensors and effectors in these deleterious events connexins and pannexins could represent a set of novel clinical diagnostic biomarkers and drug targets.
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Affiliation(s)
- Sara Crespo Yanguas
- Department of In Vitro Toxicology and Dermato-Cosmetology, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium
| | - Joost Willebrords
- Department of In Vitro Toxicology and Dermato-Cosmetology, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium
| | - Michaël Maes
- Department of In Vitro Toxicology and Dermato-Cosmetology, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium
| | - Tereza Cristina da Silva
- Department of Pathology, School of Veterinary Medicine and Animal Science, University of São Paulo, Av. Prof. Dr. Orlando Marques de Paiva 87, São Paulo SP CEP 05508-900, Brazil
| | - Isabel Veloso Alves Pereira
- Department of Pathology, School of Veterinary Medicine and Animal Science, University of São Paulo, Av. Prof. Dr. Orlando Marques de Paiva 87, São Paulo SP CEP 05508-900, Brazil
| | - Bruno Cogliati
- Department of Pathology, School of Veterinary Medicine and Animal Science, University of São Paulo, Av. Prof. Dr. Orlando Marques de Paiva 87, São Paulo SP CEP 05508-900, Brazil
| | - Maria Lucia Zaidan Dagli
- Department of Pathology, School of Veterinary Medicine and Animal Science, University of São Paulo, Av. Prof. Dr. Orlando Marques de Paiva 87, São Paulo SP CEP 05508-900, Brazil
| | - Mathieu Vinken
- Department of In Vitro Toxicology and Dermato-Cosmetology, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium
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Tork OM, Khaleel EF, Abdelmaqsoud OM. Altered Cell to Cell Communication, Autophagy and Mitochondrial Dysfunction in a Model of Hepatocellular Carcinoma: Potential Protective Effects of Curcumin and Stem Cell Therapy. Asian Pac J Cancer Prev 2016; 16:8271-9. [DOI: 10.7314/apjcp.2015.16.18.8271] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Vinken M. Regulation of connexin signaling by the epigenetic machinery. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2015; 1859:262-8. [PMID: 26566120 DOI: 10.1016/j.bbagrm.2015.11.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2015] [Revised: 11/03/2015] [Accepted: 11/06/2015] [Indexed: 12/31/2022]
Abstract
Connexins and their channels are involved in the control of all aspects of the cellular life cycle, ranging from cell growth to cell death, by mediating extracellular, intercellular and intracellular communication. These multifaceted aspects of connexin-related cellular signaling obviously require strict regulation. While connexin channel activity is mainly directed by posttranslational modifications, connexin expression as such is managed by classical cis/trans mechanisms. Over the past few years, it has become clear that connexin production is equally dictated by epigenetic actions. This paper provides an overview of the role of major determinants of the epigenome, including DNA methylation, histone acetylation and microRNA species, in connexin expression.
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Affiliation(s)
- Mathieu Vinken
- Vrije Universiteit Brussel, Department of In Vitro Toxicology and Dermato-Cosmetology, Building G, Room G226, Laarbeeklaan 103, B-1090 Brussels, Belgium.
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Maes M, Crespo Yanguas S, Willebrords J, Cogliati B, Vinken M. Connexin and pannexin signaling in gastrointestinal and liver disease. Transl Res 2015; 166:332-43. [PMID: 26051630 PMCID: PMC4570182 DOI: 10.1016/j.trsl.2015.05.005] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Revised: 04/29/2015] [Accepted: 05/08/2015] [Indexed: 12/20/2022]
Abstract
Gap junctions, which mediate intercellular communication, are key players in digestive homeostasis. They are also frequently involved in gastrointestinal and liver pathology. This equally holds true for connexin (Cx) hemichannels, the structural precursors of gap junctions, and pannexin (Panx) channels, Cx-like proteins assembled in a hemichannel configuration. Both Cx hemichannels and Panx channels facilitate extracellular communication and drive a number of deteriorative processes, such as cell death and inflammation. Cxs, Panxs, and their channels underlie a wide spectrum of gastrointestinal and liver diseases, including gastritis and peptic ulcer disease, inflammatory intestinal conditions, acute liver failure, cholestasis, hepatitis and steatosis, liver fibrosis and cirrhosis, infectious gastrointestinal pathologies, and gastrointestinal and liver cancer. This could open promising perspectives for the characterization of new targets and biomarkers for therapeutic and diagnostic clinical purposes in the area of gastroenterology and hepatology.
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Affiliation(s)
- Michaël Maes
- Department of In Vitro Toxicology and Dermato-Cosmetology, Vrije Universiteit Brussel, Brussels, Belgium
| | - Sara Crespo Yanguas
- Department of In Vitro Toxicology and Dermato-Cosmetology, Vrije Universiteit Brussel, Brussels, Belgium
| | - Joost Willebrords
- Department of In Vitro Toxicology and Dermato-Cosmetology, Vrije Universiteit Brussel, Brussels, Belgium
| | - Bruno Cogliati
- Department of Pathology, School of Veterinary Medicine and Animal Science, University of Sao Paulo, Sao Paulo, Brazil
| | - Mathieu Vinken
- Department of In Vitro Toxicology and Dermato-Cosmetology, Vrije Universiteit Brussel, Brussels, Belgium.
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Wang CX, Wang X, Liu HB, Zhou ZH. Aberrant DNA methylation and epigenetic inactivation of hMSH2 decrease overall survival of acute lymphoblastic leukemia patients via modulating cell cycle and apoptosis. Asian Pac J Cancer Prev 2014; 15:355-62. [PMID: 24528056 DOI: 10.7314/apjcp.2014.15.1.355] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
OBJECTIVE Altered regulation of many transcription factors has been shown to play important roles in the development of leukemia. hMSH2 can modulate the activity of some important transcription factors and is known to be a regulator of hematopoietic differentiation. Herein, we investigated epigenetic regulation of hMSH2 and its influence on cell growth and overall survival of acute lymphoblastic leukemia (ALL) patients. METHODS hMSH2 promoter methylation status was assessed by COBRA and pyrosequencing in 60 ALL patients and 30 healthy volunteers. mRNA and protein expression levels of hMSH2, PCNA, CyclinD1, Bcl-2 and Bax were determined by real time PCR and Western blotting, respectively. The influence of hMSH2 on cell proliferation and survival was assessed in transient and stable expression systems. RESULTS mRNA and protein expression of hMSH2 and Bcl-2 was decreased, and that of PCNA, CyclinD1 and Bax was increased in ALL patients as compared to healthy volunteers (P<0.05). hMSH2 was inactivated in ALL patients through promoter hypermethylation. Furthermore, hMSH2 hypermethylation was found in relapsed ALL patients (85.7% of all cases). The median survival of patients with hMSH2 methylation was shorter than that of patients without hMSH2 methylation (log-rank test, P=0.0035). Over-expression of hMSH2 in cell lines resulted in a significant reduction in growth and induction of apoptosis. CONCLUSIONS This study suggests that aberrant DNA methylation and epigenetic inactivation of hMSH2 play an important role in the development of ALL through altering cell growth and survival.
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Affiliation(s)
- Cai-Xia Wang
- Department of Internal Medicine, Guangzhou First People's Hospital, Guangzhou Medical University, Guangzhou, China E-mail :
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16
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Liao J, Li XF, Zhou SC, Luo Y, Liu AL, Lu WQ. Bromodichloromethane induces cell proliferation in different tissues of male F344 rats by suppression of E-cadherin expression via hypermethylation or transcriptional activation of c-myc and cyclin D1. Toxicol Lett 2013; 223:162-74. [DOI: 10.1016/j.toxlet.2013.08.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2013] [Revised: 08/14/2013] [Accepted: 08/22/2013] [Indexed: 12/31/2022]
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Mehedint MG, Zeisel SH. Choline's role in maintaining liver function: new evidence for epigenetic mechanisms. Curr Opin Clin Nutr Metab Care 2013; 16:339-45. [PMID: 23493015 PMCID: PMC3729018 DOI: 10.1097/mco.0b013e3283600d46] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
PURPOSE OF REVIEW Humans eating diets low in choline develop fatty liver and liver damage. Rodents fed choline-methionine-deficient diets not only develop fatty liver, but also progress to develop fibrosis and hepatocarcinoma. This review focuses on the role of choline in liver function, with special emphasis on the epigenetic mechanisms of action. RECENT FINDINGS Dietary intake of methyl donors like choline influences the methylation of DNA and histones, thereby altering the epigenetic regulation of gene expression. The liver is the major organ within which methylation reactions occur, and many of the hepatic genes involved in pathways for the development of fatty liver, hepatic fibrosis, and hepatocarcinomas are epigenetically regulated. SUMMARY Dietary intake of choline varies over a three-fold range and many humans have genetic polymorphisms that increase their demand for choline. Choline is an important methyl donor needed for the generation of S-adenosylmethionine. Dietary choline intake is an important modifier of epigenetic marks on DNA and histones, and thereby modulates the gene expression in many of the pathways involved in liver function and dysfunction.
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Affiliation(s)
- Mihai G Mehedint
- Nutrition Research Institute at Kannapolis, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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Niu Q, Liu H, Guan Z, Zeng Q, Guo S, He P, Guo L, Gao P, Xu B, Xu Z, Xia T, Wang A. The effect of c-Fos demethylation on sodium fluoride-induced apoptosis in L-02 cells. Biol Trace Elem Res 2012; 149:102-9. [PMID: 22528769 DOI: 10.1007/s12011-012-9392-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Accepted: 03/09/2012] [Indexed: 10/28/2022]
Abstract
To investigate the effects of sodium fluoride (NaF) on apoptosis, c-Fos mRNA and protein expression levels, and methylation status as well as Dnmt1, Dnmt3a, and Dnmt3b mRNA expression levels in human embryo hepatocyte (L-02) which were exposed to different concentrations of NaF (0, 20, 40, and 80 mg/l) for 24 h in vitro. Results showed that the percentage of apoptosis and c-Fos mRNA and protein expression levels in 40 and 80 mg/l NaF-treated groups were higher than those in the control group (P<0.05). Further, Dnmt1 mRNA expression level was significantly decreased in the 80 mg/l NaF-treated groups compared to the control group (P<0.05); Dnmt3a and Dnmt3b mRNA expression levels were significantly decreased in 40 and 80 mg/l NaF-treated groups compared to the control group (P<0.05). c-Fos methylation levels, according to the bisulfite sequencing results, were decreased in 20, 40, and 80 mg/l NaF-treated groups against the control group. These results suggest that NaF could induce apoptosis and upregulate mRNA and protein expression level of c-Fos as well as decrease mRNA expression levels of Dnmt1, Dnmt3a, and Dnmt3b in L-02 cells. The decrease in c-Fos methylation levels might be involved in the early phase of apoptosis induced by NaF in L-02 cells.
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Affiliation(s)
- Qiang Niu
- Department of Environmental Health and MOE key Lab of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Hangkong Road 13, Wuhan 430030, Hubei, People's Republic of China
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Vinken M, de Kock J, Oliveira AG, Menezes GB, Cogliati B, Dagli MLZ, Vanhaecke T, Rogiers V. Modifications in Connexin Expression in Liver Development and Cancer. ACTA ACUST UNITED AC 2012; 19:55-62. [DOI: 10.3109/15419061.2012.712576] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Blusztajn JK, Mellott TJ. Choline nutrition programs brain development via DNA and histone methylation. Cent Nerv Syst Agents Med Chem 2012; 12:82-94. [PMID: 22483275 PMCID: PMC5612430 DOI: 10.2174/187152412800792706] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2011] [Revised: 12/05/2011] [Accepted: 12/06/2011] [Indexed: 11/22/2022]
Abstract
Choline is an essential nutrient for humans. Metabolically choline is used for the synthesis of membrane phospholipids (e.g. phosphatidylcholine), as a precursor of the neurotransmitter acetylcholine, and, following oxidation to betaine, choline functions as a methyl group donor in a pathway that produces S-adenosylmethionine. As a methyl donor choline influences DNA and histone methylation--two central epigenomic processes that regulate gene expression. Because the fetus and neonate have high demands for choline, its dietary intake during pregnancy and lactation is particularly important for normal development of the offspring. Studies in rodents have shown that high choline intake during gestation improves cognitive function in adulthood and prevents memory decline associated with old age. These behavioral changes are accompanied by electrophysiological, neuroanatomical, and neurochemical changes and by altered patterns of expression of multiple cortical and hippocampal genes including those encoding key proteins that contribute to the biochemical mechanisms of learning and memory. These actions of choline are observed long after the exposure to the nutrient ended (months) and correlate with fetal hepatic and cerebral cortical choline-evoked changes in global- and gene-specific DNA cytosine methylation and with dramatic changes of the methylation pattern of lysine residues 4, 9 and 27 of histone H3. Moreover, gestational choline modulates the expression of DNA (Dnmt1, Dnmt3a) and histone (G9a/Ehmt2/Kmt1c, Suv39h1/Kmt1a) methyltransferases. In addition to the central role of DNA and histone methylation in brain development, these processes are highly dynamic in adult brain, modulate the expression of genes critical for synaptic plasticity, and are involved in mechanisms of learning and memory. A recent study documented that in a cohort of normal elderly people, verbal and visual memory function correlated positively with the amount of dietary choline consumption. It will be important to determine if these actions of choline on human cognition are mediated by epigenomic mechanisms or by its influence on acetylcholine or phospholipid synthesis.
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Affiliation(s)
- Jan Krzysztof Blusztajn
- Department of Pathology and Laboratory Medicine, Boston University School of Medicine, 72 East Concord Street, L808, Boston, MA 02118, USA.
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Pathogenetic and Prognostic Significance of Inactivation of RASSF Proteins in Human Hepatocellular Carcinoma. Mol Biol Int 2012; 2012:849874. [PMID: 22548173 PMCID: PMC3323848 DOI: 10.1155/2012/849874] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Accepted: 01/26/2012] [Indexed: 12/11/2022] Open
Abstract
Hepatocellular carcinoma (HCC) is one of the most frequent solid tumors worldwide, with limited treatment options and a dismal prognosis. Thus, there is a strong need to expand the basic and translational research on this deadly disease in order to improve the prognosis of HCC patients. Although the etiologic factors responsible for HCC development have been identified, the molecular pathogenesis of liver cancer remains poorly understood. Recent evidence has shown the frequent downregulation of Ras association domain family (RASSF) proteins both in the early and late stages of hepatocarcinogenesis. Here, we summarize the data available on the pathogenetic role of inactivation of RASSF proteins in liver cancer, the molecular mechanisms responsible for suppression of RASSF proteins in HCC, and the possible clinical implications arising from these discoveries. Altogether, the data indicate that inactivation of the RASSF1A tumor suppressor is ubiquitous in human liver cancer, while downregulation of RASSF2 and RASSF5 proteins is limited to specific HCC subsets. Also, the present findings speak in favour of therapeutic strategies aimed at reexpressing RASSF1A, RASSF2, and RASSF5 genes and/or inactivating the RASSF cellular inhibitors for the treatment of human liver cancer.
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Greco M, Chiappetta A, Bruno L, Bitonti MB. In Posidonia oceanica cadmium induces changes in DNA methylation and chromatin patterning. JOURNAL OF EXPERIMENTAL BOTANY 2012; 63:695-709. [PMID: 22058406 PMCID: PMC3254685 DOI: 10.1093/jxb/err313] [Citation(s) in RCA: 189] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2011] [Revised: 07/08/2011] [Accepted: 08/18/2011] [Indexed: 05/17/2023]
Abstract
In mammals, cadmium is widely considered as a non-genotoxic carcinogen acting through a methylation-dependent epigenetic mechanism. Here, the effects of Cd treatment on the DNA methylation patten are examined together with its effect on chromatin reconfiguration in Posidonia oceanica. DNA methylation level and pattern were analysed in actively growing organs, under short- (6 h) and long- (2 d or 4 d) term and low (10 μM) and high (50 μM) doses of Cd, through a Methylation-Sensitive Amplification Polymorphism technique and an immunocytological approach, respectively. The expression of one member of the CHROMOMETHYLASE (CMT) family, a DNA methyltransferase, was also assessed by qRT-PCR. Nuclear chromatin ultrastructure was investigated by transmission electron microscopy. Cd treatment induced a DNA hypermethylation, as well as an up-regulation of CMT, indicating that de novo methylation did indeed occur. Moreover, a high dose of Cd led to a progressive heterochromatinization of interphase nuclei and apoptotic figures were also observed after long-term treatment. The data demonstrate that Cd perturbs the DNA methylation status through the involvement of a specific methyltransferase. Such changes are linked to nuclear chromatin reconfiguration likely to establish a new balance of expressed/repressed chromatin. Overall, the data show an epigenetic basis to the mechanism underlying Cd toxicity in plants.
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Affiliation(s)
| | | | | | - Maria Beatrice Bitonti
- Department of Ecology, University of Calabria, Laboratory of Plant Cyto-physiology, Ponte Pietro Bucci, I-87036 Arcavacata di Rende, Cosenza, Italy
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Zhou ZH, Lei YX, Wang CX. Analysis of aberrant methylation in DNA repair genes during malignant transformation of human bronchial epithelial cells induced by cadmium. Toxicol Sci 2011; 125:412-7. [PMID: 22112500 DOI: 10.1093/toxsci/kfr320] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Cadmium (Cd) and its compounds are well-known human carcinogens, but the mechanisms underlying the carcinogenesis are not entirely understood yet. Aberrant methylation was investigated in order to obtain insight into the DNA repair-related epigenetic mechanisms underlying CdCl(2)-induced malignant transformation of human bronchial epithelial cells (16HBE). Gene expression and DNA methylation were assessed in untreated control cells; 5th, 15th, and 35th passage of CdCl2-treated cells and tumorigenic cells (TCs) from nude mice by using high-performance liquid chromatography, real-time PCR, Western blot analysis, and methylation-specific PCR assay. During Cd-induced malignant transformation, global DNA methylation progressively increased and was associated with the overexpression of the DNA methyltransferase genes DNMT1 and DNMT3a but not DNMT3b. Expression of both the messenger RNA and proteins of the DNA repair genes (hMSH2, ERCC1, XRCC1, and hOGG1) progressively reduced and DNA damage increased with Cd-induced transformation. The promoter regions of hMSH2, ERCC1, XRCC1, and hOGG1 were heavily methylated in the 35th passage transformed cells and the TCs. The DNA demethylating agent 5-aza-2'-deoxycytidine could reverse the Cd-induced global DNA hypermethylation, DNMT hyperactivity, and the silencing of hMSH2, ERCC1, XRCC1, and hOGG1 in a time-dependent manner. The results indicate that DNMT1 and DNMT3a overexpression can result in global DNA hypermethylation and silencing of the hMSH2, ERCC1, XRCC1, and hOGG1 genes. They may partly explain the epigenetic mechanisms underlying the carcinogenesis due to Cd.
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Affiliation(s)
- Zhi-heng Zhou
- Department of Toxicology, School of Public Health, Guangzhou Medical University, Guangzhou 510182, People's Republic of China
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Distinct DNA methylation patterns of lysophosphatidic acid receptor genes during rat hepatocarcinogenesis induced by a choline-deficient L-amino acid-defined diet. Arch Toxicol 2011; 85:1303-10. [PMID: 21290119 DOI: 10.1007/s00204-011-0656-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2010] [Accepted: 01/13/2011] [Indexed: 02/07/2023]
Abstract
Altered expressions of lysophosphatidic acid (LPA) receptor genes have been reported in tumor cells of human and rats. Recently, we detected the frequent mutations of LPA receptor-1 (LPA1) gene in rat hepatocellular carcinomas (HCCs) induced by a choline-deficient L-amino acid-defined (CDAA) diet. In this study, the DNA methylation patterns of LPA receptor genes and their expression levels during rat hepatocarcinogenesis induced by the CDAA diet were investigated. Six-week-old F344 male rats were continuously fed with the CDAA diet, and animals were then killed at 7 days and 2, 12, 20, and 75 weeks, respectively. Genomic DNAs were extracted from livers and HCCs for the assessment of methylation status by bisulfite sequencing, comparing to normal livers. The livers of rats fed the CDAA diet were unmethylated in LPA1 and LPA2 genes as well as normal livers. In LPA3 gene, although normal livers were unmethylated, the livers at 7 days and 2 and 12 weeks weakly or moderately methylated and those at 20 weeks markedly methylated. Moreover, 4 HCCs were completely methylated in LPA3 gene. Expression levels of LPA receptor genes in the livers of rats fed the CDAA diet and HCCs were correlating with DNA methylation status. These results indicate that DNA methylation status of the LPA3 gene was disturbed in the livers of rats fed the CDAA diet and established HCCs, suggesting that alterations of the LPA receptor genes might be involved during rat hepatocarcinogenesis induced by the CDAA diet.
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Abstract
Rat has been the major model species used in several biomedical fields, notably in drug development and toxicology, including carcinogenicity testing. Rat is also a useful model in basic cancer research. Several rat models of monogenic (Mendelian) human hereditary cancers are available. Some were obtained spontaneously, while others were generated either by mutagenesis of tumor suppressor genes or by transgenesis of activated oncogenes (transgenesis can be performed efficiently in the rat). In addition, among the hundreds of inbred rat strains that have been isolated, some are highly susceptible or resistant to certain types of cancer, and these divergent phenotypes were shown to be polygenic. Numerous quantitative trait loci (QTLs) controlling cancer susceptibility/resistance have been defined in linkage analyses, and several of these QTLs were physically demonstrated in congenic strains. These studies led, in particular, to rapid translation to the human, with the identification of loci controlling susceptibility to a form of multiple endocrine neoplasia (monogenic trait) and to breast cancer (polygenic disease). The biology of cancer resistance has also been analyzed, and in some (but not all) cases, it was linked to regression of preneoplasic lesions. Rat tumors have been the subject of various types of analyses, and these studies led to important conclusions, including that tumors can be classified on the basis of the identity of the inducing agent, thereby suggesting that analyses of human tumors may be valuable in determining retrospectively the role of specific carcinogens in the formation of human cancers, and of human breast cancer in particular.
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Affiliation(s)
- Claude Szpirer
- Institut de Biologie et de Médecine Moléculaires, Université Libre de Bruxelles, Gosselies, Charleroi, Belgium
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26
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Abstract
Disruption of the epigenome has been a hallmark of human cancers and has been linked with tumor pathogenesis and progression. Since epigenetic changes can be reversed in principle, studies have been carried out to identify modifiable (such as diet and lifestyle) factors, which possess epigenetic property, in hope for developing epigenetically based prevention/intervention strategies. The goal is to achieve some degree of epigenetic reprogramming, which would maintain normal gene expression status and reverse tumorigenesis through chemoprevention or lifestyle intervention such as diet modification. The ability of dietary compounds to act epigenetically in cancer cells has been studied and evidence continues to surface for constituents in food and dietary supplements to influence the epigenome and ultimately individual's risk of developing cancer. In this chapter, we summarized the existing data, both from animal and human studies, on the capacity of natural food products to influence three key epigenetic processes: DNA methylation, histone modification, and microRNA expression. As discussed in the perspective, while diet-based intervention that targets epigenetic pathways is promising, significant challenges remain in translating these scientific findings into clinical or public health practices in the context of cancer prevention.
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Affiliation(s)
- Jia Chen
- Department of Preventive Medicine, Mount Sinai School of Medicine,New York, USA
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Starlard-Davenport A, Tryndyak VP, James SR, Karpf AR, Latendresse JR, Beland FA, Pogribny IP. Mechanisms of epigenetic silencing of the Rassf1a gene during estrogen-induced breast carcinogenesis in ACI rats. Carcinogenesis 2009; 31:376-81. [PMID: 20008439 DOI: 10.1093/carcin/bgp304] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Breast cancer, the most common malignancy in women, emerges through a multistep process, encompassing the progressive sequential evolution of morphologically distinct stages from a normal cell to hyperplasia (with and without atypia), carcinoma in situ, invasive carcinoma and metastasis. The success of treatment of breast cancer could be greatly improved by the detection at early stages of cancer. In the present study, we investigated the underlying molecular mechanisms involved in breast carcinogenesis in Augustus and Copenhagen-Irish female rats, a cross between the ACI strains, induced by continuous exposure to 17beta-estradiol. The results of our study demonstrate that early stages of estrogen-induced breast carcinogenesis are characterized by altered global DNA methylation, aberrant expression of proteins responsible for the proper maintenance of DNA methylation pattern and epigenetic silencing of the critical Rassf1a (Ras-association domain family 1, isoform A) tumor suppressor gene. Interestingly, transcriptional repression of the Rassf1a gene in mammary glands during early stages of breast carcinogenesis was associated with an increase in trimethylation of histones H3 lysine 9 and H3 lysine 27 and de novo CpG island methylation and at the Rassf1a promoter and first exon. In conclusion, we demonstrate that epigenetic alterations precede formation of preneoplastic lesions indicating the significance of epigenetic events in induction of oncogenic pathways in early stages of carcinogenesis.
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Affiliation(s)
- Athena Starlard-Davenport
- Division of Biochemical Toxicology, National Center for Toxicological Research, Jefferson, AR 72079, USA
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Pogribny IP, Shpyleva SI, Muskhelishvili L, Bagnyukova TV, James SJ, Beland FA. Role of DNA damage and alterations in cytosine DNA methylation in rat liver carcinogenesis induced by a methyl-deficient diet. Mutat Res 2009; 669:56-62. [PMID: 19442675 DOI: 10.1016/j.mrfmmm.2009.05.003] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2009] [Revised: 04/27/2009] [Accepted: 05/04/2009] [Indexed: 12/16/2022]
Abstract
Currently, cancer is recognized as a disease provoked by both genetic and epigenetic events. However, the significance of early genetic and epigenetic alterations with respect to carcinogenic process in general and to liver carcinogenesis in particular remains unexplored. A lack of knowledge regarding how specific alterations during early preneoplasia may be mechanistically related to tumor formation creates a major gap in understanding the role of these genetic and epigenetic abnormalities in carcinogenesis. In the present study we investigated the contribution of DNA damage and epigenetic alterations to liver carcinogenesis induced by a methyl-deficient diet. Feeding Fisher 344 rats a methyl-deficient diet for 9 weeks resulted in DNA damage and aberrant DNA methylation. This was evidenced by an early up-regulation of the base excision DNA repair genes, accumulation of 8-oxodeoxyguanosine and 3'OH-end strand breaks in DNA, pronounced global loss of DNA methylation, and hypermethylation of CpG islands in the livers of methyl-deficient rats. These abnormalities were completely restored in the livers of rats exposed to methyl-deficiency for 9 weeks after removal of the methyl-deficient diet and re-feeding a methyl-sufficient diet. However, when rats were fed a methyl-deficient diet for 18 week and then given a methyl-sufficient diet, only DNA lesions were repaired. The methyl-sufficient diet failed to restore completely the altered DNA methylation status and prevent the progression of liver carcinogenesis. These results suggest that stable alterations in DNA methylation are a factor that promotes the progression of liver carcinogenesis. Additionally, the results indicate that epigenetic changes may be more reliable markers than DNA lesions of the carcinogenic process and carcinogen exposure.
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Affiliation(s)
- Igor P Pogribny
- Division of Biochemical Toxicology, National Center for Toxicological Research, Jefferson, AR 72079, USA.
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Vinken M, De Rop E, Decrock E, De Vuyst E, Leybaert L, Vanhaecke T, Rogiers V. Epigenetic regulation of gap junctional intercellular communication: More than a way to keep cells quiet? Biochim Biophys Acta Rev Cancer 2009; 1795:53-61. [DOI: 10.1016/j.bbcan.2008.08.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2008] [Revised: 08/14/2008] [Accepted: 08/18/2008] [Indexed: 02/07/2023]
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de Lima VMR, Oliveira CPMS, Alves VAF, Chammas MC, Oliveira EP, Stefano JT, de Mello ES, Cerri GG, Carrilho FJ, Caldwell SH. A rodent model of NASH with cirrhosis, oval cell proliferation and hepatocellular carcinoma. J Hepatol 2008; 49:1055-61. [PMID: 18929425 DOI: 10.1016/j.jhep.2008.07.024] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2008] [Revised: 05/26/2008] [Accepted: 07/08/2008] [Indexed: 12/21/2022]
Abstract
BACKGROUND/AIMS Hepatocellular carcinoma (HCC) is a well recognized complication of advanced NASH (non-alcoholic steatohepatitis). We sought to produce a rat model of NASH, cirrhosis and HCC. METHODS Adult Sprague-Dawley rats, weighing 250-300g, were fed a choline-deficient, high trans-fat diet and exposed to DEN in drinking water. After 16 weeks, the animals underwent liver ultrasound (US), sacrifice and assessment by microscopy, immunohistochemistry and transmission electron microscopy (TEM). RESULTS US revealed steatosis and focal lesions in 6 of 7. All had steatohepatitis defined as inflammation, advanced fibrosis and ballooning with Mallory-Denk bodies (MDB) with frank cirrhosis in 6. Areas of more severe injury were associated with anti-CK19 positive ductular reaction. HCC, present in all, were macro-trabecullar or solid with polyhedral cells with foci of steatosis and ballooned cells. CK19 was positive in single or solid nests of oval cells and in neoplastic hepatocytes. TEM showed ballooning with small droplet fat, dilated endoplasmic reticulum and MDB in non-neoplastic hepatocytes and small droplet steatosis in some cancer cells. CONCLUSIONS This model replicated many features of NASH including steatohepatitis with ballooning, fibrosis, cirrhosis and hepatocellular carcinoma. Oval cell proliferation was evident and the presence anti-CK 19 positivity in the cancer suggests oval cell origin of the malignancy.
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Affiliation(s)
- Vicência M R de Lima
- Department of Gastroenterology, University of São Paulo School of Medicine, Av. Dr. Enéas de Carvalho Aguiar No. 255, Instituto Central, # 9159, São Paulo 05403-000, Brazil
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Jiang G, Xu L, Song S, Zhu C, Wu Q, Zhang L, Wu L. Effects of long-term low-dose cadmium exposure on genomic DNA methylation in human embryo lung fibroblast cells. Toxicology 2008; 244:49-55. [PMID: 18077075 DOI: 10.1016/j.tox.2007.10.028] [Citation(s) in RCA: 154] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2007] [Revised: 10/26/2007] [Accepted: 10/28/2007] [Indexed: 11/25/2022]
Abstract
Cadmium is a toxic transition metal of continuing occupational and environmental concern. As a well-recognized human carcinogen, its carcinogenic mechanisms are still poorly understood. Cadmium has long been considered a non-genotoxic carcinogen and thought to act through epigenetic mechanisms. In the present study, we tested the effects of long-term low-dose cadmium exposure on DNA methylation in human embryo lung fibroblast (HLF) cells. After 2 months of exposure to 0-1.5 micromol/L cadmium, both the level of genomic DNA methylation and the enzyme activity of DNA methyltransferases (DNMTs) were increased in a concentration-related manner. Moreover, our results showed that cadmium exposure up-regulated the mRNA levels of DNMT1, DNMT3a and DNMT3b at higher concentrations. We further tested the growth dynamics of HLF cells, and observed significantly elevated growth rates, decreased cell population of G0/G1-phase and increased cell population of S-phase at 0.9, 1.2, and 1.5 micromol/L concentrations. Our study indicated that long-term low-dose cadmium exposure could disrupt DNA methylation, which may be one of the possible underlying carcinogenic mechanisms of cadmium.
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Affiliation(s)
- Gaofeng Jiang
- Faculty of Preventive Medicine, Medical College, Wuhan University of Science and Technology, Huangjiahu Campus, Wuhan 430065, Hubei Province, People's Republic of China.
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