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Survival Benefit of Statin with Anti-Angiogenesis Efficacy in Lung Cancer-Associated Pleural Fluid through FXR Modulation. Cancers (Basel) 2022; 14:cancers14112765. [PMID: 35681743 PMCID: PMC9179389 DOI: 10.3390/cancers14112765] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 05/27/2022] [Accepted: 05/30/2022] [Indexed: 11/19/2022] Open
Abstract
Simple Summary Our previous works showed that pleural fluid from lung cancer significantly induced endothelial proliferation, migration, and angiogenesis. Since endothelial metabolism was a key step in angiogenesis, we investigated the role of bile acid signaling and FXR expression in pleural angiogenesis. Elevated bile acid levels in lung-cancer-associated pleural fluid (LCPF) were characterized with positive FXR staining in pleural microvessels. We then confirmed the inhibitory effect of an FXR antagonist on LCPF-induced endothelial migration and angiogenesis. Due to the elevated protein expression in the cholesterol metabolism caused by LCPF, lipid-lowering agents with the efficacy needed to counteract LCPF-regulated angiogenesis were evaluated. Statin showed the potent efficacy needed to suppress LCPF-induced endothelial proliferation, migration, and angiogenesis through FXR inhibition. Following that, Kaplan–Meier analysis showed the survival benefit of statin exposure in patients with lung adenocarcinoma with LCPF. Our results suggest that targeting endothelial FXR signaling with statin treatment could ameliorate the angiogenesis activity of LCPF. Abstract Lung cancer-related pleural fluid (LCPF) presents as a common complication with limited treatment. Beyond its function in lipid digestion, bile acid was identified as a potent carcinogen to stimulate tumor proliferation. Previous research indicated a correlation between serum bile acid levels and the risk of developing several gastrointestinal cancers. Our study identified elevated bile acid levels in LCPF and increased farnesoid X receptor (FXR) expression as bile acid nuclear receptors in pleural microvessels of lung adenocarcinoma. Additionally, LCPF stimulated the expression of proteins involved in bile acid synthesis and cholesterol metabolism in HUVECs including CYP7A1, StAR, HMGCR, and SREBP2. LCPF-induced endothelial motility and angiogenesis were counteracted by using β-muricholic acid as an FXR antagonist. Moreover, we investigated the efficacy of cholesterol-lowering medications, such as cholestyramine, fenofibrate, and atorvastatin, in regulating LCPF-regulated angiogenesis. Along with suppressing endothelial proliferation and angiogenesis, atorvastatin treatment reversed cholesterol accumulation and endothelial junction disruption caused by LCPF. Statin treatment inhibited LCPF-induced endothelial FXR expression as well as the downstream proteins RXR and SHP. Based on the positive findings of suppressing endothelial angiogenesis, our group further incorporated the effect of statin on clinical patients complicated with LCPF. A Kaplan–Meier analysis revealed the clinical benefit of statin exposure in patients with lung adenocarcinoma with LCPF. Conclusively, our study demonstrated the ability of statin to alleviate LCPF-induced angiogenesis in patients with LCPF via FXR modulation.
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An association of ABCG8: rs11887534 polymorphism and HDL-cholesterol response to statin treatment in the Polish population. Pharmacol Rep 2021; 73:1781-1786. [PMID: 34173968 PMCID: PMC8599229 DOI: 10.1007/s43440-021-00302-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 06/07/2021] [Accepted: 06/21/2021] [Indexed: 11/17/2022]
Abstract
Background Variation in lipid changes in response to statin treatment is associated with genetic polymorphism. Sterolin-1, encoded by ABCG5, and sterolin-2, encoded by ABCG8, together form a sterol transporter. There are some reports indicating association of rs11887534 (ABCG8:c.55G > C) polymorphism with lipid concentrations, both prior to and after statin treatment. The aim of this study was to analyze both baseline plasma lipids and their concentrations in response to statin treatment with regard to ABCG8: rs11887534 polymorphism in Caucasian patients of Polish origin. Methods The study group consisted of 170 consecutive adult out-patients treated with atorvastatin or simvastatin for a minimum of 2 months. Concentrations of triglycerides (TG), total cholesterol (TC), LDL-cholesterol (LDL-C) and HDL-cholesterol (HDL-C) were measured before and after statin treatment. The ABCG8 polymorphism was identified by mini-sequencing genomic DNA extracted from peripheral blood leukocytes. Results There were no significant differences in regard to ABCG8 variants for baseline TG, TC, LDL-C and HDL-C as well as for TG, TC or LDL-C concentrations after statin treatment. However, patients carrying at least one C allele showed a decrease in post-statin HDL-C concentrations and the absolute and relative changes between post- and pre-statin HDL-C concentrations were negative in contrast to positive values in wild-type homozygotes. Conclusions Our results suggest that the c.55C allele of the ABCG8: rs11887534 polymorphism might be associated with decrease in HDL-cholesterol in response to statin treatment in Polish patients.
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Lee J, Hong EM, Jung JH, Park SW, Lee SP, Koh DH, Jang HJ, Kae SH. Atorvastatin Induces FXR and CYP7A1 Activation as a Result of the Sequential Action of PPARγ/PGC-1α/HNF-4α in Hep3B Cells. THE KOREAN JOURNAL OF GASTROENTEROLOGY 2021; 77:123-131. [PMID: 33686046 DOI: 10.4166/kjg.2020.156] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 01/15/2021] [Accepted: 01/19/2021] [Indexed: 11/03/2022]
Abstract
Backgrounds/Aims PPARγ, farnesoid X receptor (FXR) and CYP7A1 are associated with solubility of bile. This study was performed to understand a mechanism and interactions of statin-induced PPARγ, PGC-1α and HNF-4α related to the statin-induced activation of FXR and CYP7A1, and verify whether the mevalonate pathway is involved in the mechanism. Methods MTT assays were performed using cultured human Hep3B cells to determine the effect of atorvastatin on the cell proliferation. Expression levels of indicated proteins were measured using Western blotting assays by inhibiting the protein expression or not. Results Atorvastatin increased expression of PPARγ, PGC-1α, HNF-4α, FXR, and CYP7A1 in Hep3B cells. PPARγ ligand of troglitazone upregulated the expression of PGC-1α, HNF-4α, FXR, and CYP7A1 in Hep3B cells. Silencing of PPARγ, PGC1α, and HNF4α using respective siRNA demonstrated that atorvastatin-induced FXR and CYP7A1 activation required sequential action of PPARγ /PGC-1α/HNF-4α. The silencing of PPARγ completely inhibited atorvastatin-induced PGC-1α expression, and the PGC1α silencing partially inhibited atorvastatin-induced PPARγ expression. The inhibition of HNF4α did not affect atorvastatin-induced PPARγ expression, but partially inhibited atorvastatin-induced PGC-1α expression. Besides, mevalonate completely reversed the effect of atorvastatin on PPARγ, PGC-1α, HNF-4α, FXR, and CYP7A1. Conclusions Atorvastatin induces FXR and CYP7A1 activation as a result of sequential action of PPARγ/PGC-1α/HNF-4α in human hepatocytes. We propose that atorvastatin enhances solubility of cholesterol in bile by simultaneously activating of FXR and CYP7A1.
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Affiliation(s)
- Jin Lee
- Division of Gastroenterology, Department of Internal Medicine, Hallym University Dongtan Sacred Hospital, Hallym University College of Medicine, Hwaseong, Korea
| | - Eun Mi Hong
- Division of Gastroenterology, Department of Internal Medicine, Hallym University Dongtan Sacred Hospital, Hallym University College of Medicine, Hwaseong, Korea
| | - Jang Han Jung
- Division of Gastroenterology, Department of Internal Medicine, Hallym University Dongtan Sacred Hospital, Hallym University College of Medicine, Hwaseong, Korea
| | - Se Woo Park
- Division of Gastroenterology, Department of Internal Medicine, Hallym University Dongtan Sacred Hospital, Hallym University College of Medicine, Hwaseong, Korea
| | - Sang Pyo Lee
- Division of Gastroenterology, Department of Internal Medicine, Hallym University Dongtan Sacred Hospital, Hallym University College of Medicine, Hwaseong, Korea
| | - Dong Hee Koh
- Division of Gastroenterology, Department of Internal Medicine, Hallym University Dongtan Sacred Hospital, Hallym University College of Medicine, Hwaseong, Korea
| | - Hyun Joo Jang
- Division of Gastroenterology, Department of Internal Medicine, Hallym University Dongtan Sacred Hospital, Hallym University College of Medicine, Hwaseong, Korea
| | - Sea Hyub Kae
- Division of Gastroenterology, Department of Internal Medicine, Hallym University Dongtan Sacred Hospital, Hallym University College of Medicine, Hwaseong, Korea
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Hoffmeister T, Kaiser J, Lüdtke S, Drews G, Düfer M. Interactions between Atorvastatin and the Farnesoid X Receptor Impair Insulinotropic Effects of Bile Acids and Modulate Diabetogenic Risk. Mol Pharmacol 2020; 97:202-211. [PMID: 31911428 DOI: 10.1124/mol.119.118083] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 12/18/2019] [Indexed: 01/11/2023] Open
Abstract
Bile acids such as chenodeoxycholic acid (CDC) acutely enhance insulin secretion via the farnesoid X receptor (FXR). Statins, which are frequently prescribed for patients with type 2 diabetes who suffer from dyslipidemia, are known for their diabetogenic risk and are reported to interact with the FXR. Our study investigates whether this interaction is relevant for beta cell signaling and plays a role for negative effects of statins on glycemic control. Experiments were performed with islets and islet cells from C57BL/6N wild-type and FXR-knockout (KO) mice. Culturing islets with atorvastatin (15 µM) for 24 hours decreased glucose-stimulated insulin secretion by approximately 30% without affecting ATP synthesis. Prolonged exposure for 7 days lowered the concentration necessary for impairment of insulin release to 150 nM. After 24-hour culture with atorvastatin, the ability of CDC (500 nM) to elevate [Ca2+]c was diminished and the potentiating effect on insulin secretion was completely lost. Mevalonate largely reduced the negative effect of atorvastatin. Nuclear activity of FXR was reduced by atorvastatin in a mouse FXR reporter assay. The atorvastatin-induced decrease in insulin release was also present in FXR-KO mice. Although not a prerequisite, FXR seems to influence the degree of damage caused by atorvastatin depending on its interaction with CDC: Preparations responding to CDC with an increase in insulin secretion under control conditions were less impaired by atorvastatin than preparations that were nonresponsive to CDC. Extended stimulation of FXR by the synthetic agonist GW4064, which is suggested to induce translocation of FXR from the cytosol into the nucleus, increased the inhibitory effect of atorvastatin. In conclusion, atorvastatin inhibits insulin release and prevents positive effects of bile acids on beta cell function. Both interactions may contribute to progression of type 2 diabetes mellitus. SIGNIFICANCE STATEMENT: This study shows that the diabetogenic risk of statins is coupled to the activity of farnesoid X receptor (FXR)-dependent signaling pathways in beta cells. On the one hand, statins abolish the insulinotropic effects of bile acids and on the other hand, FXR determines the level of impairment of islet function by the statin.
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Affiliation(s)
- Theresa Hoffmeister
- Institute of Pharmaceutical and Medicinal Chemistry, Department of Pharmacology, Münster, Germany (T.H., S.L., M.D.) and Institute of Pharmacy, Department of Pharmacology and Clinical Pharmacy, Tübingen, Germany (J.K., G.D.)
| | - Julia Kaiser
- Institute of Pharmaceutical and Medicinal Chemistry, Department of Pharmacology, Münster, Germany (T.H., S.L., M.D.) and Institute of Pharmacy, Department of Pharmacology and Clinical Pharmacy, Tübingen, Germany (J.K., G.D.)
| | - Simon Lüdtke
- Institute of Pharmaceutical and Medicinal Chemistry, Department of Pharmacology, Münster, Germany (T.H., S.L., M.D.) and Institute of Pharmacy, Department of Pharmacology and Clinical Pharmacy, Tübingen, Germany (J.K., G.D.)
| | - Gisela Drews
- Institute of Pharmaceutical and Medicinal Chemistry, Department of Pharmacology, Münster, Germany (T.H., S.L., M.D.) and Institute of Pharmacy, Department of Pharmacology and Clinical Pharmacy, Tübingen, Germany (J.K., G.D.)
| | - Martina Düfer
- Institute of Pharmaceutical and Medicinal Chemistry, Department of Pharmacology, Münster, Germany (T.H., S.L., M.D.) and Institute of Pharmacy, Department of Pharmacology and Clinical Pharmacy, Tübingen, Germany (J.K., G.D.)
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Abstract
Abstract
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Affiliation(s)
- Angela Pirillo
- Center for the Study of Atherosclerosis, E. Bassini Hospital, Cinisello Balsamo, Milan, Italy
- IRCCS MultiMedica, Sesto S. Giovanni, Milan, Italy
| | - Alberico Luigi Catapano
- IRCCS MultiMedica, Sesto S. Giovanni, Milan, Italy
- Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan, Italy
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Stanley FM, Linder KM, Cardozo TJ. Statins Increase Plasminogen Activator Inhibitor Type 1 Gene Transcription through a Pregnane X Receptor Regulated Element. PLoS One 2015; 10:e0138097. [PMID: 26379245 PMCID: PMC4574702 DOI: 10.1371/journal.pone.0138097] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Accepted: 08/25/2015] [Indexed: 12/15/2022] Open
Abstract
Plasminogen activator inhibitor type 1 (PAI-1) is a multifunctional protein that has important roles in inflammation and wound healing. Its aberrant regulation may contribute to many disease processes such as heart disease. The PAI-1 promoter is responsive to multiple inputs including cytokines, growth factors, steroids and oxidative stress. The statin drugs, atorvastatin, mevastatin and rosuvastatin, increased basal and stimulated expression of the PAI-1 promoter 3-fold. A statin-responsive, nuclear hormone response element was previously identified in the PAI-1 promoter, but it was incompletely characterized. We characterized this direct repeat (DR) of AGGTCA with a 3-nucleotide spacer at -269/-255 using deletion and directed mutagenesis. Deletion or mutation of this element increased basal transcription from the promoter suggesting that it repressed PAI-1 transcription in the unliganded state. The half-site spacing and the ligand specificity suggested that this might be a pregnane X receptor (PXR) responsive element. Computational molecular docking showed that atorvastatin, mevastatin and rosuvastatin were structurally compatible with the PXR ligand-binding pocket in its agonist conformation. Experiments with Gal4 DNA binding domain fusion proteins showed that Gal4-PXR was activated by statins while other DR + 3 binding nuclear receptor fusions were not. Overexpression of PXR further enhanced PAI-1 transcription in response to statins. Finally, ChIP experiments using Halo-tagged PXR and RXR demonstrated that both components of the PXR-RXR heterodimer bound to this region of the PAI-1 promoter.
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Affiliation(s)
- Frederick M. Stanley
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, New York, United States of America
- Laura and Isaac Perlmutter Cancer Center, NYU Langone Medical Center, New York, New York, United States of America
| | - Kathryn M. Linder
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, New York, United States of America
| | - Timothy J. Cardozo
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, New York, United States of America
- Laura and Isaac Perlmutter Cancer Center, NYU Langone Medical Center, New York, New York, United States of America
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Byun HW, Hong EM, Park SH, Koh DH, Choi MH, Jang HJ, Kae SH, Lee J. Pravastatin activates the expression of farnesoid X receptor and liver X receptor alpha in Hep3B cells. Hepatobiliary Pancreat Dis Int 2014; 13:65-73. [PMID: 24463082 DOI: 10.1016/s1499-3872(14)60009-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND Statins are suggested to preserve gallbladder function by suppressing pro-inflammatory cytokines and preventing cholesterol accumulation in gallbladder epithelial cells. They also affect cross-talk among the nuclear hormone receptors that regulate cholesterol-bile acid metabolism in the nuclei of hepatocytes. However, there is controversy over whether or how statins change the expression of peroxisome proliferator-activated receptor (PPAR)alpha, PPARgamma, liver X receptor alpha (LXRalpha), farnesoid X receptor (FXR), ABCG5, ABCG8, and 7alpha-hydroxylase (CYP7A1) which are directly involved in the cholesterol saturation index in bile. METHODS Human Hep3B cells were cultured on dishes. MTT assays were performed to determine the appropriate concentrations of reagents to be used. The protein expression of PPARalpha and PPARgamma was measured by Western blotting analysis, and the mRNA expression of LXRalpha, FXR, ABCG5, ABCG8 and CYP7A1 was estimated by RT-PCR. RESULTS In cultured Hep3B cells, pravastatin activated PPARalpha and PPARgamma protein expression, induced stronger expression of PPARgamma than that of PPARalpha, increased LXRalpha mRNA expression, activated ABCG5 and ABCG8 mRNA expression mediated by FXR as well as LXRalpha, enhanced FXR mRNA expression, and increased CYP7A1 mRNA expression mediated by the PPARgamma and LXRalpha pathways, together or independently. CONCLUSION Our data suggested that pravastatin prevents cholesterol gallstone diseases via the increase of FXR, LXRalpha and CYP7A1 in human hepatocytes.
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Affiliation(s)
- Hyun Woo Byun
- Division of Gastroenterology, Department of Internal Medicine, Hallym University College of Medicine, Dongtan Sacred Heart Hospital, 40 Seokwoo-dong, Hwasung, Kyungki-Do 445-170, Republic of Korea.
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Howe K, Sanat F, Thumser AE, Coleman T, Plant N. The statin class of HMG-CoA reductase inhibitors demonstrate differential activation of the nuclear receptors PXR, CAR and FXR, as well as their downstream target genes. Xenobiotica 2011; 41:519-29. [PMID: 21476904 DOI: 10.3109/00498254.2011.569773] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The therapeutic class of HMG-CoA reductase inhibitors, the statins are central agents in the treatment of hypercholesterolaemia and the associated conditions of cardiovascular disease, obesity and metabolic syndrome. Although statin therapy is generally considered safe, a number of known adverse effects do occur, most commonly treatment-associated muscular pain. In vitro evidence also supports the potential for drug-drug interactions involving this class of agents, and to examine this a ligand-binding assay was used to determine the ability of six clinically used statins for their ability to directly activate the nuclear receptors pregnane X-receptor (PXR), farnesoid X-receptor (FXR) and constitutive androstane receptor (CAR), demonstrating a relative activation of PXR>FXR>CAR. Using reporter gene constructs, we demonstrated that this order of activation is mirrored at the transcriptional activation level, with PXR-mediated gene activation being pre-eminent. Finally, we described a novel regulatory loop, whereby activation of FXR by statins increases PXR reporter gene expression, potentially enhancing PXR-mediated responses. Delineating the molecular interactions of statins with nuclear receptors is an important step in understanding the full biological consequences of statin exposure. This demonstration of their ability to directly activate nuclear receptors, leading to nuclear receptor cross-talk, has important potential implications for their use within a polypharmacy paradigm.
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Affiliation(s)
- Katharine Howe
- Faculty of Health and Medical Sciences, Centre for Toxicology, University of Surrey, Surrey, UK
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Habeos IG, Ziros PG, Chartoumpekis D, Psyrogiannis A, Kyriazopoulou V, Papavassiliou AG. Simvastatin activates Keap1/Nrf2 signaling in rat liver. J Mol Med (Berl) 2008; 86:1279-85. [PMID: 18787804 DOI: 10.1007/s00109-008-0393-4] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2008] [Revised: 07/02/2008] [Accepted: 07/30/2008] [Indexed: 12/17/2022]
Abstract
Some of the statins' pleiotropic actions have been attributed to their antioxidant activity. The Nrf2 transcription factor controls the expression of a number of protective genes in response to oxidative stress. In the present study, wistar rats, primary hepatocytes as well as ST2 cells, were employed to explore the potential role of Nrf2 in mediating the reported antioxidant effects of statins. Simvastatin triggered nuclear translocation of Nrf2 in rat liver and in primary rat hepatocytes in a mevalonate-dependent and cholesterol-independent way. In liver, nuclear extracts from simvastatin-treated rats, the DNA-binding activity of Nrf2, was significantly increased and the mRNA of two known targets of Nrf2 (HO-1 and GPX2) was induced. In ST2 cells stably transfected with constructs bearing Nrf2-binding site (antioxidant responsive element), simvastatin enhanced Nrf2-mediated transcriptional activity in a mevalonate-dependent and cholesterol-independent fashion. In conclusion, activation of Keap1/Nrf2 signaling pathway by simvastatin might provide effective protection of the cell from the deleterious effects of oxidative stress.
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Affiliation(s)
- Ioannis G Habeos
- Department of Internal Medicine, School of Medicine, University of Patras, 26500, Patras, Greece
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Argo CK, Loria P, Caldwell SH, Lonardo A. Statins in liver disease: a molehill, an iceberg, or neither? Hepatology 2008; 48:662-9. [PMID: 18666246 DOI: 10.1002/hep.22402] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
A growing number of chronic liver disease patients, especially those with metabolic syndrome-associated nonalcoholic fatty liver disease or hepatitis C virus-associated dysmetabolic syndrome, will take statins to prevent cardiovascular disease. As a result, clinicians will weigh complex issues raised by the interaction of statins with liver metabolism in these disorders. In this article, we critically review data concerning statins and liver pathophysiology with an emphasis on nonalcoholic fatty liver disease and hepatitis C virus, while also touching on other chronic liver diseases. Basic research interests include statins' mechanism of action and their effects on cholesterol-related cell signaling pathways and angiogenesis. From the clinical standpoint, many chronic liver diseases increase cardiovascular risk and would undeniably benefit from sustained statin use. The false alarms and security accompanying aminotransferase monitoring, however, are disturbing in light of the scarcity of data on statins' long-term effects on liver histology. Although some actions of statins might eventually prove to be particularly useful in nonalcoholic steatohepatitis, hepatitis C virus, or hepatocellular carcinoma, others may prove harmful. The lack of definitive data makes a fully informed decision impossible. Research using histological endpoints is urgently needed to determine the indications and contraindications of this extraordinary class of agents in patients with chronic liver disease.
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Affiliation(s)
- Curtis K Argo
- Department of Medicine, Division of Gastroenterology and Hepatology, University of Virginia, Charlottesville, VA, USA
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Journe F, Laurent G, Chaboteaux C, Nonclercq D, Durbecq V, Larsimont D, Body JJ. Farnesol, a mevalonate pathway intermediate, stimulates MCF-7 breast cancer cell growth through farnesoid-X-receptor-mediated estrogen receptor activation. Breast Cancer Res Treat 2007; 107:49-61. [PMID: 17333335 DOI: 10.1007/s10549-007-9535-6] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2006] [Accepted: 01/30/2007] [Indexed: 11/25/2022]
Abstract
Farnesoid X receptor (FXR) is a metabolic nuclear receptor expressed in the liver and traditionally considered as a bile acid sensor. Yet, FXR has been recently demonstrated in other tissues and cells, such as the kidneys, the adrenals, and arterial smooth muscle cells. Immunohistochemical data reported in this study point to the expression of FXR in human breast cancer. In addition, FXR expression was also found by Western blotting and immunofluorescence microscopy in breast-cancer-derived cell lines MCF-7 (estrogen receptor [ER]-positive) and MDA-MB-231 (ER-negative). The FXR activator farnesol, a mevalonate pathway intermediate, exerts a mitogenic effect on MCF-7 cells. The growth stimulation is completely suppressed by antiestrogens. In contrast, MDA-MB-231 cells appear farnesol-insensitive, suggesting an involvement of ER in farnesol mitogenicity. In accordance with this interpretation, farnesol induces in MCF-7 cells a decrease of ER level, consistent with a phenomenon of receptor downregulation. Farnesol also increases progesterone receptor (PgR) expression in MCF-7 cells and stimulates ER-mediated gene transactivation in MVLN cells (MCF-7 cells stably transfected with an ER reporter gene). Of note, both effects of farnesol on ER expression and activity are completely suppressed by antiestrogens. In addition, farnesol-induced PgR is markedly reduced by FXR gene silencing (siRNA), demonstrating the involvement of FXR in the estrogenic effects of farnesol. Finally, coimmunoprecipitation experiments (FXR immunoprecipitation followed by Western blot analysis of ER in the immunoprecipitate) produced definite evidence that FXR interacts with ER. Altogether, these observations reveal the hitherto unreported presence of FXR in breast cancer and show that the latter receptor functionally interacts with ER. The occurrence of such a crosstalk calls for some caution regarding the pharmacological use of FXR agonists.
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Affiliation(s)
- Fabrice Journe
- Laboratory of Endocrinology and Bone Diseases, Institut Jules Bordet, Université Libre de Bruxelles, Brussels, Belgium.
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Gibson GG, Phillips A, Aouabdi S, Plant K, Plant N. Transcriptional regulation of the human pregnane-X receptor. Drug Metab Rev 2006; 38:31-49. [PMID: 16684647 DOI: 10.1080/03602530600569810] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
This review addresses the general structure and function of nuclear receptors and places specific emphasis on their role in xenosensing, resulting in the activation of a battery of genes mediating drug metabolism, conjugation, and transport. The pregnane-X receptor is a nuclear receptor that functions to control a battery of genes predominantly involved in drug metabolism and we place emphasis on how this important cellular mediator is transcriptionally activated. We have identified both positive and negative regulatory elements in the PXR promoter, the balance of which dictates the steady state expression of the PXR gene.
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Affiliation(s)
- G Gordon Gibson
- University of Surrey, School of Biomedical and Molecular Sciences, Molecular Toxicology Group, England.
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Ong TP, Heidor R, de Conti A, Dagli MLZ, Moreno FS. Farnesol and geraniol chemopreventive activities during the initial phases of hepatocarcinogenesis involve similar actions on cell proliferation and DNA damage, but distinct actions on apoptosis, plasma cholesterol and HMGCoA reductase. Carcinogenesis 2005; 27:1194-203. [PMID: 16332721 DOI: 10.1093/carcin/bgi291] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Chemopreventive activities of farnesol (FOH) and geraniol (GOH) were evaluated during the initial phases of hepatocarcinogenesis. Rats received during eight consecutive weeks 25 mg/100 g body weight FOH (FOH group) or GOH (GOH group), or only corn oil (CO group, controls). Incidence (%) and mean number of visible hepatocyte nodules/animal were inhibited in FOH group (13% and 4 +/- 1; P < 0.05), but not in GOH group (42% and 18 +/- 17, P > 0.05), compared to CO group (100% and 42 +/- 17). Mean area (mm2) and % liver section area occupied by total hepatic placental glutathione S-transferase positive preneoplastic lesions (PNLs) were reduced in FOH group (0.09 +/- 0.06; 2.8 +/- 1.3; P < 0.05) compared to CO group (0.18 +/- 0.12; 10.0 +/- 2.8), while in GOH group only the mean area of these PNL was reduced (0.11 +/- 0.09; P < 0.05), but not the % liver section area occupied by them (5.1 +/- 1.1; P > 0.05). Compared to CO group, FOH and GOH groups showed reduced (P < 0.05) PNL cell proliferation and DNA damage, but only GOH group showed increased PNL apoptosis (P < 0.05). FOH group, but not GOH group, presented reduced (P < 0.05) total plasma cholesterol levels and increased (P < 0.05) hepatic levels of 3-hydroxy-3-methylglutaryl coenzyme A (HMGCoA) reductase mRNA, compared to CO group. No differences (P > 0.05) were observed between CO, FOH and GOH regarding hepatic levels of farnesoid X activated receptor (FXR) protein. Results indicate that FOH and GOH could represent promising chemopreventive agents against hepatocarcinogenesis. Inhibition of cell proliferation and DNA damage relate to both isoprenoids' anticarcinogenic actions while induction of apoptosis specifically relates to GOH protective actions. Inhibition of HMGCoA reductase activity could be associated with FOH, but not GOH anticarcinogenic actions. FXR does not seem to be involved in the isoprenoids' chemopreventive activities.
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Affiliation(s)
- Thomas Prates Ong
- Laboratory of Diet, Nutrition and Cancer, Department of Food and Experimental Nutrition, Faculty of Pharmaceutical Sciences, University of São Paulo, São Paulo, SP, Brazil
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