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Zeng Z, Fu M, Hu Y, Wei Y, Wei X, Luo M. Regulation and signaling pathways in cancer stem cells: implications for targeted therapy for cancer. Mol Cancer 2023; 22:172. [PMID: 37853437 PMCID: PMC10583419 DOI: 10.1186/s12943-023-01877-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 10/05/2023] [Indexed: 10/20/2023] Open
Abstract
Cancer stem cells (CSCs), initially identified in leukemia in 1994, constitute a distinct subset of tumor cells characterized by surface markers such as CD133, CD44, and ALDH. Their behavior is regulated through a complex interplay of networks, including transcriptional, post-transcriptional, epigenetic, tumor microenvironment (TME), and epithelial-mesenchymal transition (EMT) factors. Numerous signaling pathways were found to be involved in the regulatory network of CSCs. The maintenance of CSC characteristics plays a pivotal role in driving CSC-associated tumor metastasis and conferring resistance to therapy. Consequently, CSCs have emerged as promising targets in cancer treatment. To date, researchers have developed several anticancer agents tailored to specifically target CSCs, with some of these treatment strategies currently undergoing preclinical or clinical trials. In this review, we outline the origin and biological characteristics of CSCs, explore the regulatory networks governing CSCs, discuss the signaling pathways implicated in these networks, and investigate the influential factors contributing to therapy resistance in CSCs. Finally, we offer insights into preclinical and clinical agents designed to eliminate CSCs.
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Affiliation(s)
- Zhen Zeng
- Laboratory of Aging Research and Cancer Agent Target, State Key Laboratory of Biotherapy, Cancer Center, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, No. 17, Block 3, Southern Renmin Road, Chengdu, Sichuan, 610041, P.R. China
| | - Minyang Fu
- Laboratory of Aging Research and Cancer Agent Target, State Key Laboratory of Biotherapy, Cancer Center, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, No. 17, Block 3, Southern Renmin Road, Chengdu, Sichuan, 610041, P.R. China
| | - Yuan Hu
- Department of Pediatric Nephrology Nursing, Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, West China Second Hospital, Sichuan University, No. 17, Block 3, Southern Renmin Road, Chengdu, Sichuan, 610041, P.R. China
| | - Yuquan Wei
- Laboratory of Aging Research and Cancer Agent Target, State Key Laboratory of Biotherapy, Cancer Center, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, No. 17, Block 3, Southern Renmin Road, Chengdu, Sichuan, 610041, P.R. China
| | - Xiawei Wei
- Laboratory of Aging Research and Cancer Agent Target, State Key Laboratory of Biotherapy, Cancer Center, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, No. 17, Block 3, Southern Renmin Road, Chengdu, Sichuan, 610041, P.R. China
| | - Min Luo
- Laboratory of Aging Research and Cancer Agent Target, State Key Laboratory of Biotherapy, Cancer Center, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, No. 17, Block 3, Southern Renmin Road, Chengdu, Sichuan, 610041, P.R. China.
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Cui W, Shen X, Agbas E, Tompkins B, Cameron-Carter H, Staudinger JL. Phosphorylation Modulates the Coregulatory Protein Exchange of the Nuclear Receptor Pregnane X Receptor. J Pharmacol Exp Ther 2020; 373:370-380. [PMID: 32205367 DOI: 10.1124/jpet.119.264762] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Accepted: 03/10/2020] [Indexed: 01/09/2023] Open
Abstract
The pregnane X receptor (PXR), or nuclear receptor (NR) 1I2, is a ligand-activated NR superfamily member that is enriched in liver and intestine in mammals. Activation of PXR regulates the expression of genes encoding key proteins involved in drug metabolism, drug efflux, and drug transport. Recent mechanistic investigations reveal that post-translational modifications (PTMs), such as phosphorylation, play a critical role in modulating the bimodal function of PXR-mediated transrepression and transactivation of target gene transcription. Upon ligand binding, PXR undergoes a conformational change that promotes dissociation of histone deacetylase-containing multiprotein corepressor protein complexes while simultaneously favoring recruitment histone acetyl transferase-containing complexes. Here we describe a novel adenoviral vector used to deliver and recover recombinant human PXR protein from primary cultures of hepatocytes. Using liquid chromatography and tandem mass spectrometry we report here that PXR is phosphorylated at amino acid residues threonine 135 (T135) and serine 221 (S221). Biochemical analysis reveals that these two residues play an important regulatory role in the cycling of corepressor and coactivator multiprotein complexes. These data further our foundational knowledge regarding the specific role of PTMs, namely phosphorylation, in regulating the biology of PXR. Future efforts are focused on using the novel tools described here to identify additional PTMs and protein partners of PXR in primary cultures of hepatocytes, an important experimental model system. SIGNIFICANCE STATEMENT: Pregnane X receptor (PXR), or nuclear receptor 1I2, is a key master regulator of drug-inducible CYP gene expression in liver and intestine in mammals. The novel biochemical tools described in this study demonstrate for the first time that in cultures of primary hepatocytes, human PXR is phosphorylated at amino acid residues threonine 135 (T135) and serine 221 (S221). Moreover, phosphorylation of PXR promotes the transrepression of its prototypical target gene CYP3A4 through modulating its interactions with coregulatory proteins.
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Affiliation(s)
- Wenqi Cui
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota (W.C.); Stowers Institute for Medical Research, Kansas City, Missouri (E.A.); Department of Bioinformatics, University of Georgia, Ethan, Georgia (X.S.); and Kansas City University of Medicine and Biosciences, Joplin, Missouri (B.T., H.C.-C., J.L.S.)
| | - Xunan Shen
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota (W.C.); Stowers Institute for Medical Research, Kansas City, Missouri (E.A.); Department of Bioinformatics, University of Georgia, Ethan, Georgia (X.S.); and Kansas City University of Medicine and Biosciences, Joplin, Missouri (B.T., H.C.-C., J.L.S.)
| | - Emre Agbas
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota (W.C.); Stowers Institute for Medical Research, Kansas City, Missouri (E.A.); Department of Bioinformatics, University of Georgia, Ethan, Georgia (X.S.); and Kansas City University of Medicine and Biosciences, Joplin, Missouri (B.T., H.C.-C., J.L.S.)
| | - Brandon Tompkins
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota (W.C.); Stowers Institute for Medical Research, Kansas City, Missouri (E.A.); Department of Bioinformatics, University of Georgia, Ethan, Georgia (X.S.); and Kansas City University of Medicine and Biosciences, Joplin, Missouri (B.T., H.C.-C., J.L.S.)
| | - Hadley Cameron-Carter
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota (W.C.); Stowers Institute for Medical Research, Kansas City, Missouri (E.A.); Department of Bioinformatics, University of Georgia, Ethan, Georgia (X.S.); and Kansas City University of Medicine and Biosciences, Joplin, Missouri (B.T., H.C.-C., J.L.S.)
| | - Jeff L Staudinger
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota (W.C.); Stowers Institute for Medical Research, Kansas City, Missouri (E.A.); Department of Bioinformatics, University of Georgia, Ethan, Georgia (X.S.); and Kansas City University of Medicine and Biosciences, Joplin, Missouri (B.T., H.C.-C., J.L.S.)
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Xing Y, Yan J, Niu Y. PXR: a center of transcriptional regulation in cancer. Acta Pharm Sin B 2020; 10:197-206. [PMID: 32082968 PMCID: PMC7016272 DOI: 10.1016/j.apsb.2019.06.012] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 06/10/2019] [Accepted: 06/20/2019] [Indexed: 02/05/2023] Open
Abstract
Pregnane X receptor (PXR, NR1I2) is a prototypical member of the nuclear receptor superfamily. PXR can be activated by both endobiotics and xenobiotics. As a key xenobiotic receptor, the cellular function of PXR is mostly exerted by its binding to the regulatory gene sequences in a ligand-dependent manner. Classical downstream target genes of PXR participate in xenobiotic responses, such as detoxification, metabolism and inflammation. Emerging evidence also implicates PXR signaling in the processes of apoptosis, cell cycle arrest, proliferation, angiogenesis and oxidative stress, which are closely related to cancer. Here, we discussed, in addition to the characterization of PXR per se, the biological function and regulatory mechanism of PXR signaling in cancer, and its potential for the targeted prevention and therapeutics.
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Affiliation(s)
- Yaqi Xing
- Department of Pharmacology, Shantou University Medical College, Shantou 515041, China
| | - Jiong Yan
- Center for Pharmacogenetics, University of Pittsburgh, PA 15261, USA
| | - Yongdong Niu
- Department of Pharmacology, Shantou University Medical College, Shantou 515041, China
- Corresponding author.
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Rigalli JP, Reichel M, Reuter T, Tocchetti GN, Dyckhoff G, Herold-Mende C, Theile D, Weiss J. The pregnane X receptor (PXR) and the nuclear receptor corepressor 2 (NCoR2) modulate cell growth in head and neck squamous cell carcinoma. PLoS One 2018; 13:e0193242. [PMID: 29470550 PMCID: PMC5823449 DOI: 10.1371/journal.pone.0193242] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Accepted: 02/07/2018] [Indexed: 01/19/2023] Open
Abstract
Head and neck squamous cell carcinoma (HNSCC) is the sixth most frequent cancer worldwide. The pregnane X receptor (PXR) is a nuclear receptor regulating several target genes associated with cancer malignancy. We here demonstrated a significant effect of PXR on HNSCC cell growth, as evidenced in PXR knock-down experiments. PXR transcriptional activity is more importantly regulated by the presence of coactivators and corepressors than by PXR protein expression. To date, there is scarce information on the regulation of PXR in HNSCC and on its role in the pathogenesis of this disease. Coactivator and corepressor expression was screened through qRT-PCR in 8 HNSCC cell lines and correlated to PXR activity, determined by using a reporter gene assay. All cell lines considerably expressed all the cofactors assessed. PXR activity negatively correlated with nuclear receptor corepressor 2 (NCoR2) expression, indicating a major role of this corepressor in PXR modulation and suggesting its potential as a surrogate for PXR activity in HNSCC. To test the association of NCoR2 with the malignant phenotype, a subset of three cell lines was transfected with an over-expression plasmid for this corepressor. Subsequently, cell growth and chemoresistance assays were performed. To elucidate the mechanisms underlying NCoR2 effects on cell growth, caspase 3/7 activity and protein levels of cleaved caspase 3 and PARP were evaluated. In HNO97 cells, NCoR2 over-expression decreased cell growth, chemoresistance and increased cleaved caspase 3 levels, caspase activity and cleaved PARP levels. On the contrary, in HNO124 and HNO210 cells, NCoR2 over-expression increased cell growth, drug resistance and decreased cleaved caspase 3 levels, caspase activity and cleaved PARP levels. In conclusion, we demonstrated a role of PXR and NCoR2 in the modulation of cell growth in HNSCC. This may contribute to a better understanding of the highly variable HNSCC therapeutic response.
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Affiliation(s)
- Juan Pablo Rigalli
- Department of Clinical Pharmacology and Pharmacoepidemiology, University of Heidelberg, Heidelberg, Germany
| | - Matthias Reichel
- Department of Clinical Pharmacology and Pharmacoepidemiology, University of Heidelberg, Heidelberg, Germany
| | - Tasmin Reuter
- Department of Clinical Pharmacology and Pharmacoepidemiology, University of Heidelberg, Heidelberg, Germany
| | - Guillermo Nicolás Tocchetti
- Department of Clinical Pharmacology and Pharmacoepidemiology, University of Heidelberg, Heidelberg, Germany
- Institute of Experimental Physiology (IFISE-CONICET), Rosario, Argentina
| | - Gerhard Dyckhoff
- Molecular Cell Biology Group, Department of Otorhinolaryngology, Head and Neck Surgery, University of Heidelberg, Heidelberg, Germany
| | - Christel Herold-Mende
- Molecular Cell Biology Group, Department of Otorhinolaryngology, Head and Neck Surgery, University of Heidelberg, Heidelberg, Germany
- Division of Neurosurgical Research, Department of Neurosurgery, University of Heidelberg, Heidelberg, Germany
| | - Dirk Theile
- Department of Clinical Pharmacology and Pharmacoepidemiology, University of Heidelberg, Heidelberg, Germany
| | - Johanna Weiss
- Department of Clinical Pharmacology and Pharmacoepidemiology, University of Heidelberg, Heidelberg, Germany
- * E-mail:
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Pavek P. Pregnane X Receptor (PXR)-Mediated Gene Repression and Cross-Talk of PXR with Other Nuclear Receptors via Coactivator Interactions. Front Pharmacol 2016; 7:456. [PMID: 27932985 PMCID: PMC5122737 DOI: 10.3389/fphar.2016.00456] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 11/14/2016] [Indexed: 12/13/2022] Open
Abstract
Pregnane X receptor is a ligand-activated nuclear receptor (NR) that mainly controls inducible expression of xenobiotics handling genes including biotransformation enzymes and drug transporters. Nowadays it is clear that PXR is also involved in regulation of intermediate metabolism through trans-activation and trans-repression of genes controlling glucose, lipid, cholesterol, bile acid, and bilirubin homeostasis. In these processes PXR cross-talks with other NRs. Accumulating evidence suggests that the cross-talk is often mediated by competing for common coactivators or by disruption of coactivation and activity of other transcription factors by the ligand-activated PXR. In this respect mainly PXR-CAR and PXR-HNF4α interference have been reported and several cytochrome P450 enzymes (such as CYP7A1 and CYP8B1), phase II enzymes (SULT1E1, Gsta2, Ugt1a1), drug and endobiotic transporters (OCT1, Mrp2, Mrp3, Oatp1a, and Oatp4) as well as intermediate metabolism enzymes (PEPCK1 and G6Pase) have been shown as down-regulated genes after PXR activation. In this review, I summarize our current knowledge of PXR-mediated repression and coactivation interference in PXR-controlled gene expression regulation.
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Affiliation(s)
- Petr Pavek
- Department of Pharmacology and Toxicology and Centre for Drug Development, Faculty of Pharmacy in Hradec Kralove, Charles University in Prague Hradec Kralove, Czechia
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Chen S, Yueh MF, Evans RM, Tukey RH. Pregnane-x-receptor controls hepatic glucuronidation during pregnancy and neonatal development in humanized UGT1 mice. Hepatology 2012; 56:658-67. [PMID: 22371261 PMCID: PMC3383890 DOI: 10.1002/hep.25671] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2011] [Accepted: 02/13/2012] [Indexed: 02/01/2023]
Abstract
UNLABELLED In humanized UDP glucuronosyltransferase-1 (hUGT1) mice that express the entire UGT1 locus, the maternal hepatic UGT1A genes are dramatically induced 12-14 days after conception. Steroid induction of the UGT1A1 gene indicates that xenobiotic sensors, such as the pregnane X receptor (PXR) and constitutive androstane receptor (CAR), may underlie the induction process. In contrast, neonatal hUGT1 mice display severe hyperbilirubinemia, with limited expression of the UGT1A genes. This study identifies PXR as both a positive and negative regulator of the UGT1A1 gene. Pregnancy hormones, in particular the glucocorticoids, target PXR as a positive regulator of human glucuronidation. Employing reverse genetics, where PXR has been genetically deleted, hUGT1/Pxr(-/-) mice show limited induction of the liver UGT1A genes during pregnancy, whereas the exact opposite occurs in newborn mice. Neonatal hUGT1 mice show delayed expression of hepatic UGT1A1 and are severely hyperbilirubinemic. However, in hUGT1/Pxr(-/-) mice, hyperbilirubinemia is greatly reduced due to induction of hepatic UGT1A1. Thus, PXR serves to repress UGT1A1 gene expression during development. Transcriptional silencing of the UGT1A1 gene was relieved in neonatal hUGT1 hepatocytes through interruption of PXR by small interfering RNA. CONCLUSION PXR is a key regulator of pregnancy induced glucuronidation capacity in addition to modulating the severity of neonatal jaundice.
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Affiliation(s)
- Shujuan Chen
- Department of Pharmacology, Laboratory of Environmental Toxicology, University of CaliforniaSan Diego, La Jolla, CA
| | - Mei-Fei Yueh
- Department of Pharmacology, Laboratory of Environmental Toxicology, University of CaliforniaSan Diego, La Jolla, CA
| | - Ronald M Evans
- Howard Hughes Medical Institute and Gene Expression Laboratory, Salk Institute of Biological StudiesLa Jolla, CA
| | - Robert H Tukey
- Department of Pharmacology, Laboratory of Environmental Toxicology, University of CaliforniaSan Diego, La Jolla, CA,Department of Chemistry & Biochemistry, Laboratory of Environmental Toxicology, University of CaliforniaSan Diego, La Jolla, CA
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Navaratnarajah P, Steele BL, Redinbo MR, Thompson NL. Rifampicin-independent interactions between the pregnane X receptor ligand binding domain and peptide fragments of coactivator and corepressor proteins. Biochemistry 2011; 51:19-31. [PMID: 22185585 DOI: 10.1021/bi2011674] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The pregnane X receptor (PXR), a member of the nuclear receptor superfamily, regulates the expression of drug-metabolizing enzymes in a ligand-dependent manner. The conventional view of nuclear receptor action is that ligand binding enhances the receptor's affinity for coactivator proteins, while decreasing its affinity for corepressors. To date, however, no known rigorous biophysical studies have been conducted to investigate the interaction among PXR, its coregulators, and ligands. In this work, steady-state total internal reflection fluorescence microscopy (TIRFM) and total internal reflection with fluorescence recovery after photobleaching were used to measure the thermodynamics and kinetics of the interaction between the PXR ligand binding domain and a peptide fragment of the steroid receptor coactivator-1 (SRC-1) in the presence and absence of the established PXR agonist, rifampicin. Equilibrium dissociation and dissociation rate constants of ~5 μM and ~2 s(-1), respectively, were obtained in the presence and absence of rifampicin, indicating that the ligand does not enhance the affinity of the PXR and SRC-1 fragments. Additionally, TIRFM was used to examine the interaction between PXR and a peptide fragment of the corepressor protein, the silencing mediator for retinoid and thyroid receptors (SMRT). An equilibrium dissociation constant of ~70 μM was obtained for SMRT in the presence and absence of rifampicin. These results strongly suggest that the mechanism of ligand-dependent activation in PXR differs significantly from that seen in many other nuclear receptors.
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Affiliation(s)
- Punya Navaratnarajah
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, North Carolina 27599-7260, United States
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Liu YH, Mo SL, Bi HC, Hu BF, Li CG, Wang YT, Huang L, Huang M, Duan W, Liu JP, Wei MQ, Zhou SF. Regulation of human pregnane X receptor and its target gene cytochrome P450 3A4 by Chinese herbal compounds and a molecular docking study. Xenobiotica 2010; 41:259-80. [PMID: 21117944 DOI: 10.3109/00498254.2010.537395] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The pregnane X receptor (PXR) plays a critical role in the regulation of human cytochrome P450 3A4 (CYP3A4) gene. In this study, we investigated the effect of an array of compounds isolated from Chinese herbal medicines on the activity of PXR using a luciferase reporter gene assay in transiently transfected HepG2 and Huh7 cells and on the expression of PXR and CYP3A4 in LS174T cells. Furthermore, molecular docking was performed to investigate the binding modes of herbal compounds with PXR. Praeruptorin A and C, salvianolic acid B, sodium danshensu, protocatechuic aldehyde, cryptotanshinone, emodin, morin, and tanshinone IIA significantly transactivated the CYP3A4 reporter gene construct in either HepG2 or Huh7 cells. The PXR mRNA expression in LS174T cells was significantly induced by physcion, protocatechuic aldehyde, salvianolic acid B, and sodium danshensu. However, epifriedelanol, morin, praeruptorin D, mulberroside A, tanshinone I, and tanshinone IIA significantly down-regulated the expression of PXR mRNA in LS174T cells. All the herbal compounds tested can be readily docked into the ligand-binding cavity of PXR mainly through hydrogen bond and aromatic interactions with Ser247, Gln285, His407, and Arg401. These findings suggest that herbal medicines can significantly regulate PXR and CYP3A4 and this has important implication in herb-drug interactions.
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Affiliation(s)
- Ya-He Liu
- School of Health Sciences & Health Innovations Research Institute, RMIT University, Bundoora, Victoria, Australia
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Pondugula SR, Dong H, Chen T. Phosphorylation and protein-protein interactions in PXR-mediated CYP3A repression. Expert Opin Drug Metab Toxicol 2009; 5:861-73. [PMID: 19505191 DOI: 10.1517/17425250903012360] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND The expression of drug-metabolizing enzymes CYPs is controlled by pregnane X receptor (PXR), and, therefore, understanding how PXR modulates CYP expression is important to minimize adverse drug interactions, one type of preventable adverse drug reaction. OBJECTIVE We review the mechanisms of PXR-mediated repression of CYP expression. METHODS We discuss the clinical implications of CYP repression and the role of signal cross-talks, including protein-protein interactions and phosphorylation of PXR and coregulators, in inhibiting PXR and repressing CYP expression. RESULTS/CONCLUSION Kinases such as cyclin-dependent kinase 2, protein kinase A, PKC and 70 kDa form of ribosomal protein S6 kinase repress CYP expression by phosphorylating and inhibiting PXR. Growth factor signaling represses CYP expression by phosphorylating and inhibiting forkhead in rhabdomyosarcoma, a co-activator of PXR. During inflammation, NF-kappaB represses both PXR and CYP expression through protein-protein interactions with the PXR pathway.
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Affiliation(s)
- Satyanarayana R Pondugula
- St. Jude Children's Research Hospital, Department of Chemical Biology and Therapeutics, 262 Danny Thomas Place, Mail Stop 1000, Memphis, TN 38105, USA
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Chang TKH. Activation of pregnane X receptor (PXR) and constitutive androstane receptor (CAR) by herbal medicines. AAPS JOURNAL 2009; 11:590-601. [PMID: 19688601 DOI: 10.1208/s12248-009-9135-y] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2009] [Accepted: 07/30/2009] [Indexed: 12/14/2022]
Abstract
Pregnane X receptor (PXR) and constitutive androstane receptor (CAR) are transcription factors that control the expression of a broad array of genes involved not only in transcellular transport and biotransformation of many drugs, other xenochemicals, and endogenous substances, such as bile acid, bilirubin, and certain vitamins, but also in various physiological/pathophysiological processes such as lipid metabolism, glucose homeostasis, and inflammation. Ligands of PXR and CAR are chemicals of diverse structures, including naturally occurring compounds present in herbal medicines. The overall aim of this article is to provide an overview of our current understanding of the role of herbal medicines as modulators of PXR and CAR.
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Affiliation(s)
- Thomas K H Chang
- Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, BC, Canada.
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