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Schöckel L, Woischke C, Surendran SA, Michl M, Schiergens T, Hölscher A, Glass F, Kreissl P, Klauschen F, Günther M, Ormanns S, Neumann J. PPARG activation promotes the proliferation of colorectal cancer cell lines and enhances the antiproliferative effect of 5-fluorouracil. BMC Cancer 2024; 24:234. [PMID: 38378472 PMCID: PMC10877928 DOI: 10.1186/s12885-024-11985-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Accepted: 02/08/2024] [Indexed: 02/22/2024] Open
Abstract
BACKGROUND Peroxisome proliferator-activated receptor gamma (PPARG) is a member of the nuclear receptor family. It is involved in the regulation of adipogenesis, lipid metabolism, insulin sensitivity, vascular homeostasis and inflammation. In addition, PPARG agonists, known as thiazolidinediones, are well established in the treatment of type 2 diabetes mellitus. PPARGs role in cancer is a matter of debate, as pro- and anti-tumour properties have been described in various tumour entities. Currently, the specific role of PPARG in patients with colorectal cancer (CRC) is not fully understood. MATERIAL AND METHODS The prognostic impact of PPARG expression was investigated by immunohistochemistry in a case-control study using a matched pair selection of CRC tumours (n = 246) with either distant metastases to the liver (n = 82), lung (n = 82) or without distant metastases (n = 82). Its effect on proliferation as well as the sensitivity to the chemotherapeutic drug 5-fluorouracil (5-FU) was examined after activation, inhibition, and transient gene knockdown of PPARG in the CRC cell lines SW403 and HT29. RESULTS High PPARG expression was significantly associated with pulmonary metastasis (p = 0.019). Patients without distant metastases had a significantly longer overall survival with low PPARG expression in their tumours compared to patients with high PPARG expression (p = 0.045). In the pulmonary metastasis cohort instead, a trend towards longer survival was observed for patients with high PPARG expression in their tumour (p = 0.059). Activation of PPARG by pioglitazone and rosiglitazone resulted in a significant dose-dependent increase in proliferation of CRC cell lines. Inhibition of PPARG by its specific inhibitor GW9662 and siRNA-mediated knockdown of PPARG significantly decreased proliferation. Activating PPARG significantly increased the CRC cell lines sensitivity to 5-FU while its inhibition decreased it. CONCLUSION The prognostic effect of PPARG expression depends on the metastasis localization in advanced CRC patients. Activation of PPARG increased malignancy associated traits such as proliferation in CRC cell lines but also increases sensitivity towards the chemotherapeutic agent 5-FU. Based on this finding, a combination therapy of PPARG agonists and 5-FU-based chemotherapy constitutes a promising strategy which should be further investigated.
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Affiliation(s)
- Leah Schöckel
- Institute of Pathology, Ludwig-Maximilians-University (LMU) München, Munich, Germany
| | - Christine Woischke
- Institute of Pathology, Ludwig-Maximilians-University (LMU) München, Munich, Germany
| | - Sai Agash Surendran
- Institute of Pathology, Ludwig-Maximilians-University (LMU) München, Munich, Germany
| | - Marlies Michl
- Department of Medicine III, University Hospital, LMU Munich, Munich, Germany
| | - Tobias Schiergens
- Department of General, Visceral and Transplantation Surgery, University Hospital, LMU Munich, Munich, Germany
| | | | | | | | - Frederick Klauschen
- Institute of Pathology, Ludwig-Maximilians-University (LMU) München, Munich, Germany
- German Cancer Consortium (DKTK), partner site Munich, a partnership between DKFZ and LMU Munich Germany, Munich, Germany
| | - Michael Günther
- Institute of Pathology, Ludwig-Maximilians-University (LMU) München, Munich, Germany
- German Cancer Consortium (DKTK), partner site Munich, a partnership between DKFZ and LMU Munich Germany, Munich, Germany
- Innpath Institute for Pathology GmbH, Tirol Kliniken, Innsbruck, Austria
| | - Steffen Ormanns
- Institute of Pathology, Ludwig-Maximilians-University (LMU) München, Munich, Germany
- German Cancer Consortium (DKTK), partner site Munich, a partnership between DKFZ and LMU Munich Germany, Munich, Germany
- Innpath Institute for Pathology GmbH, Tirol Kliniken, Innsbruck, Austria
| | - Jens Neumann
- Institute of Pathology, Ludwig-Maximilians-University (LMU) München, Munich, Germany.
- German Cancer Consortium (DKTK), partner site Munich, a partnership between DKFZ and LMU Munich Germany, Munich, Germany.
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Babaeenezhad E, Moradi Sarabi M, Rajabibazl M, Oraee-Yazdani S, Karima S. Global and Regional DNA methylation silencing of PPARγ Associated with Glioblastoma Multiforme Pathogenesis. Mol Biol Rep 2023; 50:589-597. [PMID: 36355265 DOI: 10.1007/s11033-022-08051-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 10/19/2022] [Indexed: 11/11/2022]
Abstract
BACKGROUND The relationship between peroxisome proliferator-activated receptor gamma (PPARγ) expression level and epigenetic modifications occurring in glioblastoma multiforme (GBM) pathogenesis is largely unknown. Herein, we examine the association of PPARγ expression with its promoter and genomic global DNA methylation status, as well as DNA methyltransferases (DNMTs) gene expression in GBM patients. METHODS We examined the patterns of promoter methylation and PPARγ expression in 26 GBM tissues and 13 adjacent non-tumor tissues by methylation-specific PCR (MSP), real-time PCR, and ELISA, respectively. Also, we examined the genomic global 5-methyl cytosine levels and DNMTs gene expression using ELISA and real-time PCR methods, respectively. RESULTS We found that hypermethylation on a specific region of the PPARγ promoter is significantly associated with the downregulation of the PPARγ gene and protein level in GBM patients. Interestingly, the amount of 5-methyl cytosine level was significantly reduced in GBM patients and positively correlated with PPARγ protein expression. Furthermore, the expression level of DNMT1, DNMT3A, and 3B were upregulated in GBM patients and the average expression level of all three DNMTs was positively correlated with tumor area. Also, we found that tumors from cortical regions exhibited a higher global DNA hypomethylation and PPARγ hypermethylation was related to the increase in GBM risk. CONCLUSION Our study demonstrated that global DNA methylation and PPARγ epigenetic silencing is associated with the GBM risk. Our data provide a novel molecular mechanistic insight into epigenetic silencing of PPARγ in GBM patients that may be relevant as a key tumor marker for GBM pathogenesis.
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Affiliation(s)
- Esmaeel Babaeenezhad
- Department of Clinical Biochemistry, School of Medicine, Student Research Committee, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mostafa Moradi Sarabi
- Nutritional Health Research Center, Lorestan University of Medical Sciences, Khorramabad, Iran. .,Department of Biochemistry and Genetics, School of Medicine, Lorestan University of Medical Sciences, Khorramabad, Iran.
| | - Masoumeh Rajabibazl
- Department of Clinical Biochemistry, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
| | - Saeed Oraee-Yazdani
- Functional Neurosurgery Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Saeed Karima
- Department of Clinical Biochemistry, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Whole-Exome Sequencing Identifies Pathogenic Germline Variants in Patients with Lynch-Like Syndrome. Cancers (Basel) 2022; 14:cancers14174233. [PMID: 36077770 PMCID: PMC9454535 DOI: 10.3390/cancers14174233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 05/24/2022] [Accepted: 05/30/2022] [Indexed: 11/17/2022] Open
Abstract
Simple Summary A significant proportion of families with a clinical suggestion of Lynch syndrome and screened for the known MMR genes remain without a molecular diagnosis. These patients, who generally show a suggestive family pedigree or early-onset tumors with MMR deficiency and no detectable germline variants, are referred to as having Lynch-like syndrome. To investigate underlying and potentially predisposing variants related to Lynch-like syndrome, we performed whole-exome sequencing in patients with clinical criteria for Lynch syndrome, MMR deficiency and without germline variants. This approach allowed for the identification of new variants potentially associated with Lynch-like syndrome, providing new clues to explain the familial predisposition to Lynch syndrome-related tumors in these patients, which could lead to new screening strategies for the identification of families at risk of developing cancer. Abstract Lynch syndrome (LS) is the most common hereditary colorectal cancer (CRC) syndrome, characterized by germline pathogenic variants in mismatch repair (MMR)-related genes that lead to microsatellite instability. Patients who meet the clinical criteria for LS and MMR deficiency and without any identified germline pathogenic variants are frequently considered to have Lynch-like syndrome (LLS). These patients have a higher risk of CRC and extracolonic tumors, and little is known about their underlying genetic causes. We investigated the germline spectrum of LLS patients through whole-exome sequencing (WES). A total of 20 unrelated patients with MMR deficiency who met the clinical criteria for LS and had no germline variant were subjected to germline WES. Variant classification was performed according to the American College of Medical Genetics and Genomics (ACMG) criteria. Pathogenic/likely pathogenic variants were identified in 35% of patients in known cancer genes such as MUTYH and ATM. Besides this, rare and potentially pathogenic variants were identified in the DNA repair gene POLN and other cancer-related genes such as PPARG, CTC1, DCC and ALPK1. Our study demonstrates the germline mutational status of LLS patients, a population at high risk of colorectal cancer.
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Feng L, Lu S, Zheng Z, Chen Y, Zhao Y, Song K, Xue H, Jin L, Li Y, Huang C, Li YM, Zhang J. Identification of an allosteric hotspot for additive activation of PPARγ in antidiabetic effects. Sci Bull (Beijing) 2021; 66:1559-1570. [PMID: 36654285 DOI: 10.1016/j.scib.2021.01.023] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 10/25/2020] [Accepted: 01/15/2021] [Indexed: 02/07/2023]
Abstract
Thiazolidinediones (TZDs), such as rosiglitazone (RSG), which activates peroxisome proliferator activated receptor-γ (PPARγ), are a potent class of oral antidiabetic agents with good durability. However, the clinical use of TZDs is challenging because of their side effects, including weight gain and hepatotoxicity. Here, we found that bavachinin (BVC), a lead natural product, additively activates PPARγ with low-dose RSG to preserve the maximum antidiabetic effects while reducing weight gain and hepatotoxicity in db/db mice caused by RSG monotherapy. Structural and biochemical assays demonstrated that an unexplored hotspot around Met329 and Ser332 in helix 5 is triggered by BVC cobinding to RSG-bound PPARγ, thereby allosterically stabilizing the active state of the activation-function 2 motif responsible for additive activation with RSG. Based on this hotspot, we discovered a series of new classes of allosteric agonists inducing the activity of TZDs in the same manner as BVC. Together, our data illustrate that the hotspot of PPARγ is druggable for the discovery of new allosteric synergists, and the combination therapy of allosteric synergists and TZD drugs may provide a potential alternative approach to the treatment of type 2 diabetes mellitus.
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Affiliation(s)
- Li Feng
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China; Medicinal Chemistry and Bioinformatics Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Shaoyong Lu
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China; Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Zhen Zheng
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China; State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
| | - Yingyi Chen
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Yuanyuan Zhao
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Kun Song
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
| | - Hongjuan Xue
- National Facility for Protein Science in Shanghai, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China
| | - Lihua Jin
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361005, China
| | - Yong Li
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361005, China
| | - Cheng Huang
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Yi-Ming Li
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China.
| | - Jian Zhang
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China; Medicinal Chemistry and Bioinformatics Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou 450001, China.
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Differential Effects of Cancer-Associated Mutations Enriched in Helix H3 of PPARγ. Cancers (Basel) 2020; 12:cancers12123580. [PMID: 33266062 PMCID: PMC7761077 DOI: 10.3390/cancers12123580] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 11/20/2020] [Accepted: 11/27/2020] [Indexed: 01/07/2023] Open
Abstract
Peroxisome proliferator-activated receptor gamma (PPARγ) has recently been revealed to regulate tumor microenvironments. In particular, genetic alterations of PPARγ found in various cancers have been reported to play important roles in tumorigenesis by affecting PPARγ transactivation. In this study, we found that helix H3 of the PPARγ ligand-binding domain (LBD) has a number of sites that are mutated in cancers. To uncover underlying molecular mechanisms between helix H3 mutations and tumorigenesis, we performed structure‒function studies on the PPARγ LBDs containing helix H3 mutations found in cancers. Interestingly, PPARγ Q286E found in bladder cancer induces a constitutively active conformation of PPARγ LBD and thus abnormal activation of PPARγ/RXRα pathway, which suggests tumorigenic roles of PPARγ in bladder cancer. In contrast, other helix H3 mutations found in various cancers impair ligand binding essential for transcriptional activity of PPARγ. These data indicate that cancer-associated mutations clustered in helix H3 of PPARγ LBD exhibit differential effects in PPARγ-mediated tumorigenesis and provide a basis for the development of new biomarkers targeting tumor microenvironments.
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Jaladanki CK, He Y, Zhao LN, Maurer-Stroh S, Loo LH, Song H, Fan H. Virtual screening of potentially endocrine-disrupting chemicals against nuclear receptors and its application to identify PPARγ-bound fatty acids. Arch Toxicol 2020; 95:355-374. [PMID: 32909075 PMCID: PMC7811525 DOI: 10.1007/s00204-020-02897-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 08/27/2020] [Indexed: 12/17/2022]
Abstract
Nuclear receptors (NRs) are key regulators of energy homeostasis, body development, and sexual reproduction. Xenobiotics binding to NRs may disrupt natural hormonal systems and induce undesired adverse effects in the body. However, many chemicals of concerns have limited or no experimental data on their potential or lack-of-potential endocrine-disrupting effects. Here, we propose a virtual screening method based on molecular docking for predicting potential endocrine-disrupting chemicals (EDCs) that bind to NRs. For 12 NRs, we systematically analyzed how multiple crystal structures can be used to distinguish actives and inactives found in previous high-throughput experiments. Our method is based on (i) consensus docking scores from multiple structures at a single functional state (agonist-bound or antagonist-bound), (ii) multiple functional states (agonist-bound and antagonist-bound), and (iii) multiple pockets (orthosteric site and alternative sites) of these NRs. We found that the consensus enrichment from multiple structures is better than or comparable to the best enrichment from a single structure. The discriminating power of this consensus strategy was further enhanced by a chemical similarity-weighted scoring scheme, yielding better or comparable enrichment for all studied NRs. Applying this optimized method, we screened 252 fatty acids against peroxisome proliferator-activated receptor gamma (PPARγ) and successfully identified 3 previously unknown fatty acids with Kd = 100-250 μM including two furan fatty acids: furannonanoic acid (FNA) and furanundecanoic acid (FUA), and one cyclopropane fatty acid: phytomonic acid (PTA). These results suggested that the proposed method can be used to rapidly screen and prioritize potential EDCs for further experimental evaluations.
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Affiliation(s)
- Chaitanya K Jaladanki
- Bioinformatics Institute (BII), Agency for Science, Technology, and Research (A*STAR), 30 Biopolis Street, Matrix No. 07-01, Singapore, 138671, Singapore
- Toxicity Mode-of-Action Discovery (ToxMAD) Platform, Innovations in Food and Chemical Safety Programme, Agency for Science, Technology, and Research (A*STAR), Singapore, 138671, Singapore
| | - Yang He
- Institute of Molecular and Cell Biology, 61 Biopolis Drive, Singapore, 138673, Singapore
| | - Li Na Zhao
- Bioinformatics Institute (BII), Agency for Science, Technology, and Research (A*STAR), 30 Biopolis Street, Matrix No. 07-01, Singapore, 138671, Singapore
| | - Sebastian Maurer-Stroh
- Bioinformatics Institute (BII), Agency for Science, Technology, and Research (A*STAR), 30 Biopolis Street, Matrix No. 07-01, Singapore, 138671, Singapore
- Toxicity Mode-of-Action Discovery (ToxMAD) Platform, Innovations in Food and Chemical Safety Programme, Agency for Science, Technology, and Research (A*STAR), Singapore, 138671, Singapore
| | - Lit-Hsin Loo
- Bioinformatics Institute (BII), Agency for Science, Technology, and Research (A*STAR), 30 Biopolis Street, Matrix No. 07-01, Singapore, 138671, Singapore
- Toxicity Mode-of-Action Discovery (ToxMAD) Platform, Innovations in Food and Chemical Safety Programme, Agency for Science, Technology, and Research (A*STAR), Singapore, 138671, Singapore
| | - Haiwei Song
- Institute of Molecular and Cell Biology, 61 Biopolis Drive, Singapore, 138673, Singapore.
| | - Hao Fan
- Bioinformatics Institute (BII), Agency for Science, Technology, and Research (A*STAR), 30 Biopolis Street, Matrix No. 07-01, Singapore, 138671, Singapore.
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Broekema M, Savage D, Monajemi H, Kalkhoven E. Gene-gene and gene-environment interactions in lipodystrophy: Lessons learned from natural PPARγ mutants. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1864:715-732. [DOI: 10.1016/j.bbalip.2019.02.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 01/13/2019] [Accepted: 02/02/2019] [Indexed: 12/13/2022]
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Broekema MF, Massink MPG, Donato C, de Ligt J, Schaarschmidt J, Borgman A, Schooneman MG, Melchers D, Gerding MN, Houtman R, Bonvin AMJJ, Majithia AR, Monajemi H, van Haaften GW, Soeters MR, Kalkhoven E. Natural helix 9 mutants of PPARγ differently affect its transcriptional activity. Mol Metab 2019; 20:115-127. [PMID: 30595551 PMCID: PMC6358588 DOI: 10.1016/j.molmet.2018.12.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 12/05/2018] [Accepted: 12/11/2018] [Indexed: 12/17/2022] Open
Abstract
OBJECTIVE The nuclear receptor PPARγ is the master regulator of adipocyte differentiation, distribution, and function. In addition, PPARγ induces terminal differentiation of several epithelial cell lineages, including colon epithelia. Loss-of-function mutations in PPARG result in familial partial lipodystrophy subtype 3 (FPDL3), a rare condition characterized by aberrant adipose tissue distribution and severe metabolic complications, including diabetes. Mutations in PPARG have also been reported in sporadic colorectal cancers, but the significance of these mutations is unclear. Studying these natural PPARG mutations provides valuable insights into structure-function relationships in the PPARγ protein. We functionally characterized a novel FPLD3-associated PPARγ L451P mutation in helix 9 of the ligand binding domain (LBD). Interestingly, substitution of the adjacent amino acid K450 was previously reported in a human colon carcinoma cell line. METHODS We performed a detailed side-by-side functional comparison of these two PPARγ mutants. RESULTS PPARγ L451P shows multiple intermolecular defects, including impaired cofactor binding and reduced RXRα heterodimerisation and subsequent DNA binding, but not in DBD-LBD interdomain communication. The K450Q mutant displays none of these functional defects. Other colon cancer-associated PPARγ mutants displayed diverse phenotypes, ranging from complete loss of activity to wildtype activity. CONCLUSIONS Amino acid changes in helix 9 can differently affect LBD integrity and function. In addition, FPLD3-associated PPARγ mutations consistently cause intra- and/or intermolecular defects; colon cancer-associated PPARγ mutations on the other hand may play a role in colon cancer onset and progression, but this is not due to their effects on the most well-studied functional characteristics of PPARγ.
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Affiliation(s)
- Marjoleine F Broekema
- Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands; Department of Molecular Cancer Research, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Maarten P G Massink
- Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands; Department of Genetics, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Cinzia Donato
- Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands; Department of Molecular Cancer Research, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Joep de Ligt
- Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands; Department of Genetics, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Joerg Schaarschmidt
- Bijvoet Center for Biomolecular Research, Faculty of Science, Utrecht University, Utrecht, the Netherlands
| | - Anouska Borgman
- Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands; Department of Molecular Cancer Research, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Marieke G Schooneman
- Department of Internal Medicine, Amsterdam University Medical Centers, Amsterdam, the Netherlands
| | - Diana Melchers
- PamGene International B. V., 's-Hertogenbosch, the Netherlands
| | | | - René Houtman
- PamGene International B. V., 's-Hertogenbosch, the Netherlands
| | - Alexandre M J J Bonvin
- Bijvoet Center for Biomolecular Research, Faculty of Science, Utrecht University, Utrecht, the Netherlands
| | - Amit R Majithia
- Division of Endocrinology, Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA
| | - Houshang Monajemi
- Department of Endocrinology and Metabolism, Amsterdam University Medical Centers, Amsterdam, the Netherlands; Rijnstate Hospital, Arnhem, the Netherlands
| | - Gijs W van Haaften
- Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands; Department of Genetics, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Maarten R Soeters
- Department of Endocrinology and Metabolism, Amsterdam University Medical Centers, Amsterdam, the Netherlands
| | - Eric Kalkhoven
- Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands; Department of Molecular Cancer Research, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands.
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Aprile M, Cataldi S, Ambrosio MR, D’Esposito V, Lim K, Dietrich A, Blüher M, Savage DB, Formisano P, Ciccodicola A, Costa V. PPARγΔ5, a Naturally Occurring Dominant-Negative Splice Isoform, Impairs PPARγ Function and Adipocyte Differentiation. Cell Rep 2018; 25:1577-1592.e6. [DOI: 10.1016/j.celrep.2018.10.035] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 08/21/2018] [Accepted: 10/08/2018] [Indexed: 12/17/2022] Open
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Vallée A, Lecarpentier Y. Crosstalk Between Peroxisome Proliferator-Activated Receptor Gamma and the Canonical WNT/β-Catenin Pathway in Chronic Inflammation and Oxidative Stress During Carcinogenesis. Front Immunol 2018; 9:745. [PMID: 29706964 PMCID: PMC5908886 DOI: 10.3389/fimmu.2018.00745] [Citation(s) in RCA: 233] [Impact Index Per Article: 38.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2018] [Accepted: 03/26/2018] [Indexed: 12/19/2022] Open
Abstract
Inflammation and oxidative stress are common and co-substantial pathological processes accompanying, promoting, and even initiating numerous cancers. The canonical WNT/β-catenin pathway and peroxisome proliferator-activated receptor gamma (PPARγ) generally work in opposition. If one of them is upregulated, the other one is downregulated and vice versa. WNT/β-catenin signaling is upregulated in inflammatory processes and oxidative stress and in many cancers, although there are some exceptions for cancers. The opposite is observed with PPARγ, which is generally downregulated during inflammation and oxidative stress and in many cancers. This helps to explain in part the opposite and unidirectional profile of the canonical WNT/β-catenin signaling and PPARγ in these three frequent and morbid processes that potentiate each other and create a vicious circle. Many intracellular pathways commonly involved downstream will help maintain and amplify inflammation, oxidative stress, and cancer. Thus, many WNT/β-catenin target genes such as c-Myc, cyclin D1, and HIF-1α are involved in the development of cancers. Nuclear factor-kappaB (NFκB) can activate many inflammatory factors such as TNF-α, TGF-β, interleukin-6 (IL-6), IL-8, MMP, vascular endothelial growth factor, COX2, Bcl2, and inducible nitric oxide synthase. These factors are often associated with cancerous processes and may even promote them. Reactive oxygen species (ROS), generated by cellular alterations, stimulate the production of inflammatory factors such as NFκB, signal transducer and activator transcription, activator protein-1, and HIF-α. NFκB inhibits glycogen synthase kinase-3β (GSK-3β) and therefore activates the canonical WNT pathway. ROS activates the phosphatidylinositol 3 kinase/protein kinase B (PI3K/Akt) signaling in many cancers. PI3K/Akt also inhibits GSK-3β. Many gene mutations of the canonical WNT/β-catenin pathway giving rise to cancers have been reported (CTNNB1, AXIN, APC). Conversely, a significant reduction in the expression of PPARγ has been observed in many cancers. Moreover, PPARγ agonists promote cell cycle arrest, cell differentiation, and apoptosis and reduce inflammation, angiogenesis, oxidative stress, cell proliferation, invasion, and cell migration. All these complex and opposing interactions between the canonical WNT/β-catenin pathway and PPARγ appear to be fairly common in inflammation, oxidative stress, and cancers.
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Affiliation(s)
| | - Yves Lecarpentier
- Centre de Recherche Clinique, Grand Hôpital de l'Est Francilien (GHEF), Meaux, France
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Commonalities in the Association between PPARG and Vitamin D Related with Obesity and Carcinogenesis. PPAR Res 2016; 2016:2308249. [PMID: 27579030 PMCID: PMC4992792 DOI: 10.1155/2016/2308249] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Accepted: 05/15/2016] [Indexed: 02/07/2023] Open
Abstract
The PPAR nuclear receptor family has acquired great relevance in the last decade, which is formed by three different isoforms (PPARα, PPARβ/δ, and PPAR ϒ). Those nuclear receptors are members of the steroid receptor superfamily which take part in essential metabolic and life-sustaining actions. Specifically, PPARG has been implicated in the regulation of processes concerning metabolism, inflammation, atherosclerosis, cell differentiation, and proliferation. Thus, a considerable amount of literature has emerged in the last ten years linking PPARG signalling with metabolic conditions such as obesity and diabetes, cardiovascular disease, and, more recently, cancer. This review paper, at crossroads of basic sciences, preclinical, and clinical data, intends to analyse the last research concerning PPARG signalling in obesity and cancer. Afterwards, possible links between four interrelated actors will be established: PPARG, the vitamin D/VDR system, obesity, and cancer, opening up the door to further investigation and new hypothesis in this fascinating area of research.
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Is the Mouse a Good Model of Human PPARγ-Related Metabolic Diseases? Int J Mol Sci 2016; 17:ijms17081236. [PMID: 27483259 PMCID: PMC5000634 DOI: 10.3390/ijms17081236] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 07/19/2016] [Accepted: 07/21/2016] [Indexed: 12/21/2022] Open
Abstract
With the increasing number of patients affected with metabolic diseases such as type 2 diabetes, obesity, atherosclerosis and insulin resistance, academic researchers and pharmaceutical companies are eager to better understand metabolic syndrome and develop new drugs for its treatment. Many studies have focused on the nuclear receptor peroxisome proliferator-activated receptor gamma (PPARγ), which plays a crucial role in adipogenesis and lipid metabolism. These studies have been able to connect this transcription factor to several human metabolic diseases. Due to obvious limitations concerning experimentation in humans, animal models—mainly mouse models—have been generated to investigate the role of PPARγ in different tissues. This review focuses on the metabolic features of human and mouse PPARγ-related diseases and the utility of the mouse as a model.
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PPARG in Human Adipogenesis: Differential Contribution of Canonical Transcripts and Dominant Negative Isoforms. PPAR Res 2014; 2014:537865. [PMID: 24790595 PMCID: PMC3981527 DOI: 10.1155/2014/537865] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Revised: 02/03/2014] [Accepted: 02/05/2014] [Indexed: 12/30/2022] Open
Abstract
The nuclear receptor PPARγ is a key regulator of adipogenesis, and alterations of its function are associated with different pathological processes related to metabolic syndrome. We recently identified two PPARG transcripts encoding dominant negative PPARγ isoforms. The existence of different PPARG variants suggests that alternative splicing is crucial to modulate PPARγ function, underlying some underestimated aspects of its regulation. Here we investigate PPARG expression in different tissues and cells affected in metabolic syndrome and, in particular, during adipocyte differentiation of human mesenchymal stem cells. We defined the transcript-specific expression pattern of PPARG variants encoding both canonical and dominant negative isoforms and identified a novel PPARG transcript, γ1ORF4. Our analysis indicated that, during adipogenesis, the transcription of alternative PPARG variants is regulated in a time-specific manner through differential usage of distinct promoters. In addition, our analysis describes—for the first time—the differential contribution of three ORF4 variants to this process, suggesting a still unexplored role for these dominant negative isoforms during adipogenesis. Therefore, our results highlight crucial aspects of PPARG regulation, suggesting the need of further investigation to rule out the differential impact of all PPARG transcripts in both physiologic and pathologic conditions, such as metabolism-related disorders.
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Auclair M, Vigouroux C, Boccara F, Capel E, Vigeral C, Guerci B, Lascols O, Capeau J, Caron-Debarle M. Peroxisome proliferator-activated receptor-γ mutations responsible for lipodystrophy with severe hypertension activate the cellular renin-angiotensin system. Arterioscler Thromb Vasc Biol 2013; 33:829-38. [PMID: 23393388 DOI: 10.1161/atvbaha.112.300962] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
OBJECTIVE Inactivating peroxisome proliferator-activated receptor-γ (PPARγ) mutations lead to a syndrome of familial partial lipodystrophy (FPLD3) associated with early-onset severe hypertension. PPARγ can repress the vascular renin-angiotensin system (RAS) and angiotensin II receptor 1 expression. We evaluated the relationships between PPARγ inactivation and cellular RAS using FPLD3 patients' cells and human vascular smooth muscle cells expressing mutant or wild-type PPARγ. Approach and Results- We identified 2 novel PPARG mutations, R165T and L339X, located in the DNA and ligand-binding domains of PPARγ, respectively in 4 patients from 2 FPLD3 families. In cultured skin fibroblasts and peripheral blood mononuclear cells from the 4 patients and healthy controls, we compared markers of RAS activation, oxidative stress, and inflammation, and tested the effect of modulators of PPARγ and angiotensin II receptor 1. We studied the impact of the 2 mutations on the transcriptional activity of PPARγ and on the vascular RAS in transfected human vascular smooth muscle cells. Systemic RAS was not altered in patients. However, RAS markers were overexpressed in patients' fibroblasts and peripheral blood mononuclear cells, as in vascular cells expressing mutant PPARγ. Angiotensin II-mediated mitogen-activated protein kinase activity increased in patients' fibroblasts, consistent with RAS constitutive activation. Patients' cells also displayed oxidative stress and inflammation. PPARγ activation and angiotensin II receptor 1 mRNA silencing reversed RAS overactivation, oxidative stress, and inflammation, arguing for a role of angiotensin II receptor 1 in these processes. CONCLUSIONS Two novel FPLD3-linked PPARG mutations are associated with a defective transrepression of cellular RAS leading to cellular dysfunction, which might contribute to the specific FPLD3-linked severe hypertension.
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Affiliation(s)
- Martine Auclair
- INSERM UMRS938, Centre de Recherche Saint Antoine, Paris, France
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PPARs Signaling and Cancer in the Gastrointestinal System. PPAR Res 2012; 2012:560846. [PMID: 23028383 PMCID: PMC3458283 DOI: 10.1155/2012/560846] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2012] [Revised: 07/23/2012] [Accepted: 08/07/2012] [Indexed: 12/27/2022] Open
Abstract
Nowadays, the study of the peroxisome proliferators activated receptors (PPARs) as potential targets for cancer prevention and therapy has gained a strong interest. From a biological point of view, the overall responsibility of PPARs in cancer development and progression is still controversial since several studies report both antiproliferative and tumor-promoting actions for these signaling molecules in human cancer cells and animal models. In this paper, we discuss PPARs functions in the context of different types of gastrointestinal cancer.
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Sabatino L, Fucci A, Pancione M, Carafa V, Nebbioso A, Pistore C, Babbio F, Votino C, Laudanna C, Ceccarelli M, Altucci L, Bonapace IM, Colantuoni V. UHRF1 coordinates peroxisome proliferator activated receptor gamma (PPARG) epigenetic silencing and mediates colorectal cancer progression. Oncogene 2012; 31:5061-72. [PMID: 22286757 DOI: 10.1038/onc.2012.3] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Peroxisome proliferator-activated receptor gamma (PPARG) inactivation has been identified as an important step in colorectal cancer (CRC) progression, although the events involved have been partially clarified. UHRF1 is emerging as a cofactor that coordinates the epigenetic silencing of tumor suppressor genes, but its role in CRC remains elusive. Here, we report that UHRF1 negatively regulates PPARG and is associated with a higher proliferative, clonogenic and migration potential. Consistently, UHRF1 ectopic expression induces PPARG repression through its recruitment on the PPARG promoter fostering DNA methylation and histone repressive modifications. In agreement, UHRF1 knockdown elicits PPARG re-activation, accompanied by positive histone marks and DNA demethylation, corroborating its role in PPARG silencing. UHRF1 overexpression, as well as PPARG-silencing, imparts higher growth rate and phenotypic features resembling those occurring in the epithelial-mesenchymal transition. In our series of 110 sporadic CRCs, high UHRF1-expressing tumors are characterized by an undifferentiated phenotype, higher proliferation rate and poor clinical outcome only in advanced stages III-IV. In addition, the inverse relationship with PPARG found in vitro is detected in vivo and UHRF1 prognostic significance appears closely related to PPARG low expression, as remarkably validated in an independent dataset. The results demonstrate that UHRF1 regulates PPARG silencing and both genes appear to be part of a complex regulatory network. These findings suggest that the relationship between UHRF1 and PPARG may have a relevant role in CRC progression.
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Affiliation(s)
- L Sabatino
- Department of Biological, Geological and Environmental Sciences, University of Sannio, Benevento, Italy
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Pancione M, Sabatino L, Fucci A, Carafa V, Nebbioso A, Forte N, Febbraro A, Parente D, Ambrosino C, Normanno N, Altucci L, Colantuoni V. Epigenetic silencing of peroxisome proliferator-activated receptor γ is a biomarker for colorectal cancer progression and adverse patients' outcome. PLoS One 2010; 5:e14229. [PMID: 21151932 PMCID: PMC2997072 DOI: 10.1371/journal.pone.0014229] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2010] [Accepted: 11/09/2010] [Indexed: 12/17/2022] Open
Abstract
The relationship between peroxisome proliferator-activated receptor γ (PPARG) expression and epigenetic changes occurring in colorectal-cancer pathogenesis is largely unknown. We investigated whether PPARG is epigenetically regulated in colorectal cancer (CRC) progression. PPARG expression was assessed in CRC tissues and paired normal mucosa by western blot and immunohistochemistry and related to patients' clinicopathological parameters and survival. PPARG promoter methylation was analyzed by methylation-specific-PCR and bisulphite sequencing. PPARG expression and promoter methylation were similarly examined also in CRC derived cell lines. Chromatin immunoprecipitation in basal conditions and after epigenetic treatment was performed along with knocking-down experiments of putative regulatory factors. Gene expression was monitored by immunoblotting and functional assays of cell proliferation and invasiveness. Methylation on a specific region of the promoter is strongly correlated with PPARG lack of expression in 30% of primary CRCs and with patients' poor prognosis. Remarkably, the same methylation pattern is found in PPARG-negative CRC cell lines. Epigenetic treatment with 5'-aza-2'-deoxycytidine can revert this condition and, in combination with trichostatin A, dramatically re-activates gene transcription and receptor activity. Transcriptional silencing is due to the recruitment of MeCP2, HDAC1 and EZH2 that impart repressive chromatin signatures determining an increased cell proliferative and invasive potential, features that can experimentally be reverted. Our findings provide a novel mechanistic insight into epigenetic silencing of PPARG in CRC that may be relevant as a prognostic marker of tumor progression.
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Affiliation(s)
- Massimo Pancione
- Department of Biological and Environmental Sciences, University of Sannio, Benevento, Italy
| | - Lina Sabatino
- Department of Biological and Environmental Sciences, University of Sannio, Benevento, Italy
| | - Alessandra Fucci
- Department of Biological and Environmental Sciences, University of Sannio, Benevento, Italy
| | - Vincenzo Carafa
- Department of General Pathology, Second University of Naples, Napoli, Italy
| | - Angela Nebbioso
- Department of General Pathology, Second University of Naples, Napoli, Italy
| | - Nicola Forte
- Departments of Medical Oncology and Clinical Pathology, Fatebenefratelli Hospital, Benevento, Italy
| | - Antonio Febbraro
- Departments of Medical Oncology and Clinical Pathology, Fatebenefratelli Hospital, Benevento, Italy
| | - Domenico Parente
- Departments of Medical Oncology and Clinical Pathology, Fatebenefratelli Hospital, Benevento, Italy
| | - Concetta Ambrosino
- Department of Biological and Environmental Sciences, University of Sannio, Benevento, Italy
- Biogem “G. Salvatore” Genetic Research Institute, Ariano Irpino, Italy
| | - Nicola Normanno
- Pharmacogenomic Laboratory, Center for Oncology Research, Mercogliano, Italy
| | - Lucia Altucci
- Department of General Pathology, Second University of Naples, Napoli, Italy
- CNR-IGB, Napoli, Italy
| | - Vittorio Colantuoni
- Department of Biological and Environmental Sciences, University of Sannio, Benevento, Italy
- Biogem “G. Salvatore” Genetic Research Institute, Ariano Irpino, Italy
- * E-mail:
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Costa V, Gallo MA, Letizia F, Aprile M, Casamassimi A, Ciccodicola A. PPARG: Gene Expression Regulation and Next-Generation Sequencing for Unsolved Issues. PPAR Res 2010; 2010:409168. [PMID: 20871817 PMCID: PMC2943117 DOI: 10.1155/2010/409168] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2010] [Accepted: 07/08/2010] [Indexed: 01/01/2023] Open
Abstract
Peroxisome proliferator-activated receptor gamma (PPARγ) is one of the most extensively studied ligand-inducible transcription factors (TFs), able to modulate its transcriptional activity through conformational changes. It is of particular interest because of its pleiotropic functions: it plays a crucial role in the expression of key genes involved in adipogenesis, lipid and glucid metabolism, atherosclerosis, inflammation, and cancer. Its protein isoforms, the wide number of PPARγ target genes, ligands, and coregulators contribute to determine the complexity of its function. In addition, the presence of genetic variants is likely to affect expression levels of target genes although the impact of PPARG gene variations on the expression of target genes is not fully understood. The introduction of massively parallel sequencing platforms-in the Next Generation Sequencing (NGS) era-has revolutionized the way of investigating the genetic causes of inherited diseases. In this context, DNA-Seq for identifying-within both coding and regulatory regions of PPARG gene-novel nucleotide variations and haplotypes associated to human diseases, ChIP-Seq for defining a PPARγ binding map, and RNA-Seq for unraveling the wide and intricate gene pathways regulated by PPARG, represent incredible steps toward the understanding of PPARγ in health and disease.
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Affiliation(s)
- Valerio Costa
- Institute of Genetics and Biophysics “Adriano Buzzati-Traverso” (IGB), CNR, 80131 Naples, Italy
| | | | - Francesca Letizia
- Institute of Genetics and Biophysics “Adriano Buzzati-Traverso” (IGB), CNR, 80131 Naples, Italy
| | - Marianna Aprile
- Institute of Genetics and Biophysics “Adriano Buzzati-Traverso” (IGB), CNR, 80131 Naples, Italy
| | - Amelia Casamassimi
- Institute of Genetics and Biophysics “Adriano Buzzati-Traverso” (IGB), CNR, 80131 Naples, Italy
- Department of General Pathology, 1st School of Medicine, Second University of Naples, 80138 Naples, Italy
| | - Alfredo Ciccodicola
- Institute of Genetics and Biophysics “Adriano Buzzati-Traverso” (IGB), CNR, 80131 Naples, Italy
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