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Dvořák Z, Vyhlídalová B, Pečinková P, Li H, Anzenbacher P, Špičáková A, Anzenbacherová E, Chow V, Liu J, Krause H, Wilson D, Berés T, Tarkowski P, Chen D, Mani S. In vitro safety signals for potential clinical development of the anti-inflammatory pregnane X receptor agonist FKK6. Bioorg Chem 2024; 144:107137. [PMID: 38245951 DOI: 10.1016/j.bioorg.2024.107137] [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: 11/24/2023] [Revised: 12/25/2023] [Accepted: 01/14/2024] [Indexed: 01/23/2024]
Abstract
Based on the mimicry of microbial metabolites, functionalized indoles were demonstrated as the ligands and agonists of the pregnane X receptor (PXR). The lead indole, FKK6, displayed PXR-dependent protective effects in DSS-induced colitis in mice and in vitro cytokine-treated intestinal organoid cultures. Here, we report on the initial in vitro pharmacological profiling of FKK6. FKK6-PXR interactions were characterized by hydrogen-deuterium exchange mass spectrometry. Screening FKK6 against potential cellular off-targets (G protein-coupled receptors, steroid and nuclear receptors, ion channels, and xenobiotic membrane transporters) revealed high PXR selectivity. FKK6 has poor aqueous solubility but was highly soluble in simulated gastric and intestinal fluids. A large fraction of FKK6 was bound to plasma proteins and chemically stable in plasma. The partition coefficient of FKK6 was 2.70, and FKK6 moderately partitioned into red blood cells. In Caco2 cells, FKK6 displayed high permeability (A-B: 22.8 × 10-6 cm.s-1) and no active efflux. These data are indicative of essentially complete in vivo absorption of FKK6. The data from human liver microsomes indicated that FKK6 is rapidly metabolized by cytochromes P450 (t1/2 5 min), notably by CYP3A4. Two oxidized FKK6 derivatives, including DC73 (N6-oxide) and DC97 (C19-phenol), were detected, and these metabolites had 5-7 × lower potency as PXR agonists than FKK6. This implies that despite high intestinal absorption, FKK6 is rapidly eliminated by the liver, and its PXR effects are predicted to be predominantly in the intestines. In conclusion, the PXR ligand and agonist FKK6 has a suitable pharmacological profile supporting its potential preclinical development.
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Affiliation(s)
- Zdeněk Dvořák
- Department of Cell Biology and Genetics, Faculty of Science, Palacký University, Šlechtitelů 27, 783 71 Olomouc, Czech Republic.
| | - Barbora Vyhlídalová
- Department of Cell Biology and Genetics, Faculty of Science, Palacký University, Šlechtitelů 27, 783 71 Olomouc, Czech Republic
| | - Petra Pečinková
- Department of Cell Biology and Genetics, Faculty of Science, Palacký University, Šlechtitelů 27, 783 71 Olomouc, Czech Republic
| | - Hao Li
- Department of Medicine and Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Pavel Anzenbacher
- Department of Pharmacology, Faculty of Medicine and Dentistry, Palacký University, Hněvotínská 5, 779 00 Olomouc, Czech Republic
| | - Alena Špičáková
- Department of Pharmacology, Faculty of Medicine and Dentistry, Palacký University, Hněvotínská 5, 779 00 Olomouc, Czech Republic
| | - Eva Anzenbacherová
- Department of Medical Chemistry and Biochemistry, Faculty of Medicine and Dentistry, Palacký University, Hněvotínská 5, 779 00 Olomouc, Czech Republic
| | - Vimanda Chow
- Department of Chemistry, York University, 6 Thompson Road, M3J 1L3, ON, Toronto, Canada
| | - Jiabao Liu
- Department of Molecular Genetics, Donnelly Centre for Cellular and Biomolecular Research, 160 College Street, M5S 3E1, ON, Toronto, Canada
| | - Henry Krause
- Department of Molecular Genetics, Donnelly Centre for Cellular and Biomolecular Research, 160 College Street, M5S 3E1, ON, Toronto, Canada
| | - Derek Wilson
- Department of Chemistry, York University, 6 Thompson Road, M3J 1L3, ON, Toronto, Canada
| | - Tibor Berés
- Czech Advanced Technology and Research Institute, Palacký University, Šlechtitelů 27, 783 71 Olomouc, Czech Republic
| | - Petr Tarkowski
- Czech Advanced Technology and Research Institute, Palacký University, Šlechtitelů 27, 783 71 Olomouc, Czech Republic; Department of Genetic Resources for Vegetables, Medicinal and Special Plants, Centre of the Region Haná for Biotechnological and Agricultural Research, Crop Research Institute, Šlechtitelů 27, 783 71 Olomouc, Czech Republic
| | - Dajun Chen
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Sridhar Mani
- Department of Medicine and Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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Florke Gee RR, Huber AD, Chen T. Regulation of PXR in drug metabolism: chemical and structural perspectives. Expert Opin Drug Metab Toxicol 2024; 20:9-23. [PMID: 38251638 PMCID: PMC10939797 DOI: 10.1080/17425255.2024.2309212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Accepted: 01/19/2024] [Indexed: 01/23/2024]
Abstract
INTRODUCTION Pregnane X receptor (PXR) is a master xenobiotic sensor that transcriptionally controls drug metabolism and disposition pathways. PXR activation by pharmaceutical drugs, natural products, environmental toxins, etc. may decrease drug efficacy and increase drug-drug interactions and drug toxicity, indicating a therapeutic value for PXR antagonists. However, PXR's functions in physiological events, such as intestinal inflammation, indicate that PXR activators may be useful in certain disease contexts. AREAS COVERED We review the reported roles of PXR in various physiological and pathological processes including drug metabolism, cancer, inflammation, energy metabolism, and endobiotic homeostasis. We then highlight specific cellular and chemical routes that modulate PXR activity and discuss the functional consequences. Databases searched and inclusive dates: PubMed, 1 January 1980 to 10 January 2024. EXPERT OPINION Knowledge of PXR's drug metabolism function has helped drug developers produce small molecules without PXR-mediated metabolic liabilities, and further understanding of PXR's cellular functions may offer drug development opportunities in multiple disease settings.
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Affiliation(s)
- Rebecca R. Florke Gee
- Graduate School of Biomedical Sciences, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Andrew D. Huber
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Taosheng Chen
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
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3
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Neal WM, Pandey P, Khan SI, Khan IA, Chittiboyina AG. Machine learning and traditional QSAR modeling methods: a case study of known PXR activators. J Biomol Struct Dyn 2024; 42:903-917. [PMID: 37059719 DOI: 10.1080/07391102.2023.2196701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 03/22/2023] [Indexed: 04/16/2023]
Abstract
Pregnane X receptor (PXR), extensively expressed in human tissues related to digestion and metabolism, is responsible for recognizing and detoxifying diverse xenobiotics encountered by humans. To comprehend the promiscuous nature of PXR and its ability to bind a variety of ligands, computational approaches, viz., quantitative structure-activity relationship (QSAR) models, aid in the rapid dereplication of potential toxicological agents and mitigate the number of animals used to establish a meaningful regulatory decision. Recent advancements in machine learning techniques accommodating larger datasets are expected to aid in developing effective predictive models for complex mixtures (viz., dietary supplements) before undertaking in-depth experiments. Five hundred structurally diverse PXR ligands were used to develop traditional two-dimensional (2D) QSAR, machine-learning-based 2D-QSAR, field-based three-dimensional (3D) QSAR, and machine-learning-based 3D-QSAR models to establish the utility of predictive machine learning methods. Additionally, the applicability domain of the agonists was established to ensure the generation of robust QSAR models. A prediction set of dietary PXR agonists was used to externally-validate generated QSAR models. QSAR data analysis revealed that machine-learning 3D-QSAR techniques were more accurate in predicting the activity of external terpenes with an external validation squared correlation coefficient (R2) of 0.70 versus an R2 of 0.52 in machine-learning 2D-QSAR. Additionally, a visual summary of the binding pocket of PXR was assembled from the field 3D-QSAR models. By developing multiple QSAR models in this study, a robust groundwork for assessing PXR agonism from various chemical backbones has been established in anticipation of the identification of potential causative agents in complex mixtures.
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Affiliation(s)
- William M Neal
- Division of Pharmacognosy, Department of BioMolecular Sciences, School of Pharmacy, The University of Mississippi, University, MS, USA
| | - Pankaj Pandey
- National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, School of Pharmacy, The University of Mississippi, University, MS, USA
| | - Shabana I Khan
- Division of Pharmacognosy, Department of BioMolecular Sciences, School of Pharmacy, The University of Mississippi, University, MS, USA
- National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, School of Pharmacy, The University of Mississippi, University, MS, USA
| | - Ikhlas A Khan
- Division of Pharmacognosy, Department of BioMolecular Sciences, School of Pharmacy, The University of Mississippi, University, MS, USA
- National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, School of Pharmacy, The University of Mississippi, University, MS, USA
| | - Amar G Chittiboyina
- National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, School of Pharmacy, The University of Mississippi, University, MS, USA
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Huber AD, Poudel S, Li Y, Lin W, Wu J, Miller DJ, Chen T. Ligand flexibility and binding pocket malleability cooperate to allow selective PXR activation by analogs of a promiscuous nuclear receptor ligand. Structure 2023; 31:1545-1555.e9. [PMID: 37729916 PMCID: PMC10872772 DOI: 10.1016/j.str.2023.08.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 08/01/2023] [Accepted: 08/23/2023] [Indexed: 09/22/2023]
Abstract
The human nuclear receptor (NR) family of transcription factors contains 48 proteins that bind lipophilic molecules. Approved NR therapies have had immense success treating various diseases, but lack of selectivity has hindered efforts to therapeutically target the majority of NRs due to unpredictable off-target effects. The synthetic ligand T0901317 was originally discovered as a potent agonist of liver X receptors (LXRα/β) but subsequently found to target additional NRs, with activation of pregnane X receptor (PXR) being as potent as that of LXRs. We previously showed that directed rigidity reduces PXR binding by T0901317 derivatives through unfavorable protein remodeling. Here, we use a similar approach to achieve selectivity for PXR over other T0901317-targeted NRs. One molecule, SJPYT-318, accomplishes selectivity by favorably utilizing PXR's flexible binding pocket and surprisingly binding in a new mode distinct from the parental T0901317. Our work provides a structure-guided framework to achieve NR selectivity from promiscuous compounds.
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Affiliation(s)
- Andrew D Huber
- Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Shyaron Poudel
- Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Yongtao Li
- Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Wenwei Lin
- Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Jing Wu
- Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Darcie J Miller
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Taosheng Chen
- Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
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5
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Cochran AG, Flynn M. GNE-235: A Lead Compound Selective for the Second Bromodomain of PBRM1. J Med Chem 2023; 66:13116-13134. [PMID: 37702400 DOI: 10.1021/acs.jmedchem.3c01149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/14/2023]
Abstract
Bromodomains are acetyl-lysine binding modules that are found in different classes of chromatin-interacting proteins. Among these are large chromatin remodeling complexes such as BAF and PBAF (variants of human SWI/SNF). Previous work has identified chemical probes targeting a subset of the bromodomains present in the BAF and PBAF complexes. Selective inhibitors of the individual bromodomains have proven challenging to discover, as the domains are highly similar. Here, elaboration of an aminopyridazine scaffold used previously to develop probes for the bromodomains of SMARCA2, SMARCA4, and the fifth bromodomain of PBRM1 yielded compounds with both potency and unusual selectivity for the second bromodomain of PBRM1. One of these, GNE-235, and its enantiomer control GNE-234 are suggested for initial cellular investigations of the function of the second bromodomain of PBRM1.
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Affiliation(s)
- Andrea G Cochran
- Department of Biological Chemistry, Genentech, Inc., South San Francisco, California 94080, United States
| | - Megan Flynn
- Department of Biological Chemistry, Genentech, Inc., South San Francisco, California 94080, United States
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6
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Poudel S, Huber AD, Chen T. Regulation of Nuclear Receptors PXR and CAR by Small Molecules and Signal Crosstalk: Roles in Drug Metabolism and Beyond. Drug Metab Dispos 2023; 51:228-236. [PMID: 36116789 PMCID: PMC9900866 DOI: 10.1124/dmd.122.000858] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 08/16/2022] [Accepted: 08/29/2022] [Indexed: 01/31/2023] Open
Abstract
Pregnane X receptor (PXR) and constitutive androstane receptor (CAR) are ligand-activated transcription factors that regulate the expression of drug metabolizing enzymes and drug transporters. Since their discoveries, they have been studied as important factors for regulating processes related to drug efficacy, drug toxicity, and drug-drug interactions. However, their vast ligand-binding profiles extend into additional spaces, such as endogenously produced chemicals, microbiome metabolites, dietary compounds, and environmental pollutants. Therefore, PXR and CAR can respond to an enormous abundance of stimuli, resulting in significant shifts in metabolic programs and physiologic homeostasis. Naturally, PXR and CAR have been implicated in various diseases related to homeostatic perturbations, such as inflammatory bowel disorders, diabetes, and certain cancers. Recent findings have injected the field with new signaling mechanisms and tools to dissect the complex PXR and CAR biology and have strengthened the potential for future PXR and CAR modulators in the clinic. Here, we describe the historical and ongoing importance of PXR and CAR in drug metabolism pathways and how this history has evolved into new mechanisms that regulate and are regulated by these xenobiotic receptors, with a specific focus on small molecule ligands. To effectively convey the impact of newly emerging research, we have arranged five diverse and representative key recent advances, four specific challenges, and four perspectives on future directions. SIGNIFICANCE STATEMENT: PXR and CAR are key transcription factors that regulate homeostatic detoxification of the liver and intestines. Diverse chemicals bind to these nuclear receptors, triggering their transcriptional tuning of the cellular metabolic response. This minireview revisits the importance of PXR and CAR in pharmaceutical drug responses and highlights recent results with implications beyond drug metabolism.
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Affiliation(s)
- Shyaron Poudel
- Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, Tennessee
| | - Andrew D Huber
- Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, Tennessee
| | - Taosheng Chen
- Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, Tennessee
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7
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Dvořák Z, Li H, Mani S. Microbial Metabolites as Ligands to Xenobiotic Receptors: Chemical Mimicry as Potential Drugs of the Future. Drug Metab Dispos 2023; 51:219-227. [PMID: 36184080 PMCID: PMC9900867 DOI: 10.1124/dmd.122.000860] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 08/28/2022] [Accepted: 09/19/2022] [Indexed: 01/31/2023] Open
Abstract
Xenobiotic receptors, such as the pregnane X receptor, regulate multiple host physiologic pathways including xenobiotic metabolism, certain aspects of cellular metabolism, and innate immunity. These ligand-dependent nuclear factors regulate gene expression via genomic recognition of specific promoters and transcriptional activation of the gene. Natural or endogenous ligands are not commonly associated with this class of receptors; however, since these receptors are expressed in a cell-type specific manner in the liver and intestines, there has been significant recent effort to characterize microbially derived metabolites as ligands for these receptors. In general, these metabolites are thought to be weak micromolar affinity ligands. This journal anniversary minireview focuses on recent efforts to derive potentially nontoxic microbial metabolite chemical mimics that could one day be developed as drugs combating xenobiotic receptor-modifying pathophysiology. The review will include our perspective on the field and recommend certain directions for future research. SIGNIFICANCE STATEMENT: Xenobiotic receptors (XRs) regulate host drug metabolism, cellular metabolism, and immunity. Their presence in host intestines allows them to function not only as xenosensors but also as a response to the complex metabolic environment present in the intestines. Specifically, this review focuses on describing microbial metabolite-XR interactions and the translation of these findings toward discovery of novel chemical mimics as potential drugs of the future for diseases such as inflammatory bowel disease.
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Affiliation(s)
- Zdeněk Dvořák
- Department of Cell Biology and Genetics, Palacký University, Olomouc, Czech Republic (Z.D.); Departments of Medicine (H.L., S.M.), Molecular Pharmacology (S.M.), and Genetics (S.M.), Albert Einstein College of Medicine, Bronx, New York, USA
| | - Hao Li
- Department of Cell Biology and Genetics, Palacký University, Olomouc, Czech Republic (Z.D.); Departments of Medicine (H.L., S.M.), Molecular Pharmacology (S.M.), and Genetics (S.M.), Albert Einstein College of Medicine, Bronx, New York, USA
| | - Sridhar Mani
- Department of Cell Biology and Genetics, Palacký University, Olomouc, Czech Republic (Z.D.); Departments of Medicine (H.L., S.M.), Molecular Pharmacology (S.M.), and Genetics (S.M.), Albert Einstein College of Medicine, Bronx, New York, USA
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8
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Li Y, Lin W, Chai SC, Wu J, Annu K, Chen T. Design and Optimization of 1 H-1,2,3-Triazole-4-carboxamides as Novel, Potent, and Selective Inverse Agonists and Antagonists of PXR. J Med Chem 2022; 65:16829-16859. [PMID: 36480704 PMCID: PMC9789209 DOI: 10.1021/acs.jmedchem.2c01640] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The pregnane X receptor (PXR) is a key regulator of drug metabolism. Many drugs bind to and activate PXR, causing adverse drug responses. This suggests that PXR inhibitors have therapeutic value, but potent PXR inhibitors have so far been lacking. Herein, we report the structural optimization of a series of 1H-1,2,3-triazole-4-carboxamides compounds that led to the discovery of compound 85 as a selective and the most potent inverse agonist and antagonist of PXR, with low nanomolar IC50 values for binding and cellular activity. Importantly, compound 89, a close analog of 85, is a selective and pure antagonist with low nanomolar IC50 values for binding and cellular activity. This study has provided novel, selective, and most potent PXR inhibitors (a dual inverse agonist/antagonist and a pure antagonist) for use in basic research and future clinical studies and also shed light on how to reduce the binding affinity of a compound to PXR.
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Affiliation(s)
- Yongtao Li
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN, 38105, USA
| | - Wenwei Lin
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN, 38105, USA
| | - Sergio C. Chai
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN, 38105, USA
| | - Jing Wu
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN, 38105, USA
| | - Kavya Annu
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN, 38105, USA
| | - Taosheng Chen
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN, 38105, USA
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9
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Allosteric Antagonism of the Pregnane X Receptor (PXR): Current-State-of-the-Art and Prediction of Novel Allosteric Sites. Cells 2022; 11:cells11192974. [PMID: 36230936 PMCID: PMC9563780 DOI: 10.3390/cells11192974] [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: 07/29/2022] [Revised: 09/20/2022] [Accepted: 09/20/2022] [Indexed: 11/26/2022] Open
Abstract
The pregnane X receptor (PXR, NR1I2) is a xenobiotic-activated transcription factor with high levels of expression in the liver. It not only plays a key role in drug metabolism and elimination, but also promotes tumor growth, drug resistance, and metabolic diseases. It has been proposed as a therapeutic target for type II diabetes, metabolic syndrome, and inflammatory bowel disease, and PXR antagonists have recently been considered as a therapy for colon cancer. There are currently no PXR antagonists that can be used in a clinical setting. Nevertheless, due to the large and complex ligand-binding pocket (LBP) of the PXR, it is challenging to discover PXR antagonists at the orthosteric site. Alternative ligand binding sites of the PXR have also been proposed and are currently being studied. Recently, the AF-2 allosteric binding site of the PXR has been identified, with several compounds modulating the site discovered. Herein, we aimed to summarize our current knowledge of allosteric modulation of the PXR as well as our attempt to unlock novel allosteric sites. We describe the novel binding function 3 (BF-3) site of PXR, which is also common for other nuclear receptors. In addition, we also mention a novel allosteric site III based on in silico prediction. The identified allosteric sites of the PXR provide new insights into the development of safe and efficient allosteric modulators of the PXR receptor. We therefore propose that novel PXR allosteric sites might be promising targets for treating chronic metabolic diseases and some cancers.
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Mustonen EK, Pantsar T, Rashidian A, Reiner J, Schwab M, Laufer S, Burk O. Target Hopping from Protein Kinases to PXR: Identification of Small-Molecule Protein Kinase Inhibitors as Selective Modulators of Pregnane X Receptor from TüKIC Library. Cells 2022; 11:cells11081299. [PMID: 35455978 PMCID: PMC9030254 DOI: 10.3390/cells11081299] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 04/05/2022] [Accepted: 04/07/2022] [Indexed: 02/08/2023] Open
Abstract
Small-molecule protein kinase inhibitors are used for the treatment of cancer, but off-target effects hinder their clinical use. Especially off-target activation of the pregnane X receptor (PXR) has to be considered, as it not only governs drug metabolism and elimination, but also can promote tumor growth and cancer drug resistance. Consequently, PXR antagonism has been proposed for improving cancer drug therapy. Here we aimed to identify small-molecule kinase inhibitors of the Tübingen Kinase Inhibitor Collection (TüKIC) compound library that would act also as PXR antagonists. By a combination of in silico screen and confirmatory cellular reporter gene assays, we identified four novel PXR antagonists and a structurally related agonist with a common phenylaminobenzosuberone scaffold. Further characterization using biochemical ligand binding and cellular protein interaction assays classified the novel compounds as mixed competitive/noncompetitive, passive antagonists, which bind PXR directly and disrupt its interaction with coregulatory proteins. Expression analysis of prototypical PXR target genes ABCB1 and CYP3A4 in LS174T colorectal cancer cells and HepaRG hepatocytes revealed novel antagonists as selective receptor modulators, which showed gene- and tissue-specific effects. These results demonstrate the possibility of dual PXR and protein kinase inhibitors, which might represent added value in cancer therapy.
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Affiliation(s)
- Enni-Kaisa Mustonen
- Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, and University of Tuebingen, 72074 Tuebingen, Germany; (E.-K.M.); (M.S.)
| | - Tatu Pantsar
- Department of Pharmaceutical and Medicinal Chemistry, Institute of Pharmaceutical Sciences, University of Tuebingen, 72076 Tuebingen, Germany; (T.P.); (J.R.); (S.L.)
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, 70210 Kuopio, Finland
| | - Azam Rashidian
- Department of Internal Medicine VIII, University Hospital Tuebingen, 72076 Tuebingen, Germany;
| | - Juliander Reiner
- Department of Pharmaceutical and Medicinal Chemistry, Institute of Pharmaceutical Sciences, University of Tuebingen, 72076 Tuebingen, Germany; (T.P.); (J.R.); (S.L.)
| | - Matthias Schwab
- Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, and University of Tuebingen, 72074 Tuebingen, Germany; (E.-K.M.); (M.S.)
- Departments of Clinical Pharmacology and Biochemistry and Pharmacy, University of Tuebingen, 72076 Tuebingen, Germany
- Cluster of Excellence iFIT (EXC 2180) “Image-Guided and Functionally Instructed Tumor Therapies”, University of Tuebingen, 72076 Tuebingen, Germany
| | - Stefan Laufer
- Department of Pharmaceutical and Medicinal Chemistry, Institute of Pharmaceutical Sciences, University of Tuebingen, 72076 Tuebingen, Germany; (T.P.); (J.R.); (S.L.)
- Cluster of Excellence iFIT (EXC 2180) “Image-Guided and Functionally Instructed Tumor Therapies”, University of Tuebingen, 72076 Tuebingen, Germany
- Tuebingen Center for Academic Drug Discovery & Development (TüCAD2), 72076 Tuebingen, Germany
| | - Oliver Burk
- Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, and University of Tuebingen, 72074 Tuebingen, Germany; (E.-K.M.); (M.S.)
- Correspondence: ; Tel.: +49-711-8101-5091
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Hirte S, Burk O, Tahir A, Schwab M, Windshügel B, Kirchmair J. Development and Experimental Validation of Regularized Machine Learning Models Detecting New, Structurally Distinct Activators of PXR. Cells 2022; 11:cells11081253. [PMID: 35455933 PMCID: PMC9029776 DOI: 10.3390/cells11081253] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 03/30/2022] [Indexed: 02/04/2023] Open
Abstract
The pregnane X receptor (PXR) regulates the metabolism of many xenobiotic and endobiotic substances. In consequence, PXR decreases the efficacy of many small-molecule drugs and induces drug-drug interactions. The prediction of PXR activators with theoretical approaches such as machine learning (ML) proves challenging due to the ligand promiscuity of PXR, which is related to its large and flexible binding pocket. In this work we demonstrate, by the example of random forest models and support vector machines, that classifiers generated following classical training procedures often fail to predict PXR activity for compounds that are dissimilar from those in the training set. We present a novel regularization technique that penalizes the gap between a model’s training and validation performance. On a challenging test set, this technique led to improvements in Matthew correlation coefficients (MCCs) by up to 0.21. Using these regularized ML models, we selected 31 compounds that are structurally distinct from known PXR ligands for experimental validation. Twelve of them were confirmed as active in the cellular PXR ligand-binding domain assembly assay and more hits were identified during follow-up studies. Comprehensive analysis of key features of PXR biology conducted for three representative hits confirmed their ability to activate the PXR.
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Affiliation(s)
- Steffen Hirte
- Division of Pharmaceutical Chemistry, Department of Pharmaceutical Sciences, Faculty of Life Sciences, University of Vienna, 1090 Vienna, Austria;
| | - Oliver Burk
- Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, University of Tübingen, 70376 Stuttgart, Germany; (O.B.); (M.S.)
| | - Ammar Tahir
- Division of Pharmacognosy, Department of Pharmaceutical Sciences, Faculty of Life Sciences, University of Vienna, 1090 Vienna, Austria;
| | - Matthias Schwab
- Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, University of Tübingen, 70376 Stuttgart, Germany; (O.B.); (M.S.)
- Departments of Clinical Pharmacology and Biochemistry and Pharmacy, University of Tuebingen, 72074 Tübingen, Germany
- Cluster of Excellence IFIT (EXC 2180) “Image-Guided and Functionally Instructed Tumor Therapies”, University of Tübingen, 72074 Tübingen, Germany
| | - Björn Windshügel
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Discovery Research Screening Port, 22525 Hamburg, Germany;
- Department of Life Sciences and Chemistry, Jacobs University Bremen, 28759 Bremen, Germany
| | - Johannes Kirchmair
- Division of Pharmaceutical Chemistry, Department of Pharmaceutical Sciences, Faculty of Life Sciences, University of Vienna, 1090 Vienna, Austria;
- Correspondence: ; Tel.: +43-1-4277-55104
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12
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Liu T, Beck JP, Hao J. A concise review on hPXR ligand-recognizing residues and structure-based strategies to alleviate hPXR transactivation risk. RSC Med Chem 2022; 13:129-137. [PMID: 35308029 PMCID: PMC8864553 DOI: 10.1039/d1md00348h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 01/03/2022] [Indexed: 01/21/2023] Open
Abstract
The human pregnane X receptor (hPXR) regulates the expression of major drug metabolizing enzymes. A wide range of drug candidates bind and activate hPXR, and hence are at risk of increasing drug-drug interactions and reducing clinical efficacy. hPXR structural features that function as hot spots for ligand binding are identified and highlighted in this concise review. Based on literature structure-activity relationship data as case studies, structure-based strategies to mitigate hPXR transactivation are summarized for medicinal chemists.
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Affiliation(s)
- Tao Liu
- Discovery Chemistry Research & Technologies, Eli Lilly and Company, Lilly Biotechnology Center 10290 Campus Point Drive San Diego CA 92121 USA
| | - James P Beck
- Discovery Chemistry Research & Technologies, Eli Lilly and Company, Lilly Biotechnology Center 10290 Campus Point Drive San Diego CA 92121 USA
| | - Junliang Hao
- Discovery Chemistry Research & Technologies, Eli Lilly and Company, Lilly Biotechnology Center 10290 Campus Point Drive San Diego CA 92121 USA
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13
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Discrepancy in interactions and conformational dynamics of pregnane X receptor (PXR) bound to an agonist and a novel competitive antagonist. Comput Struct Biotechnol J 2022; 20:3004-3018. [PMID: 35782743 PMCID: PMC9218138 DOI: 10.1016/j.csbj.2022.06.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 06/09/2022] [Accepted: 06/09/2022] [Indexed: 11/22/2022] Open
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14
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The Nuclear Receptor PXR in Chronic Liver Disease. Cells 2021; 11:cells11010061. [PMID: 35011625 PMCID: PMC8750019 DOI: 10.3390/cells11010061] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 12/21/2021] [Accepted: 12/24/2021] [Indexed: 02/06/2023] Open
Abstract
Pregnane X receptor (PXR), a nuclear receptor known for modulating the transcription of drug metabolizing enzymes and transporters (DMETs), such as cytochrome P450 3A4 and P-glycoprotein, is functionally involved in chronic liver diseases of different etiologies. Furthermore, PXR activity relates to that of other NRs, such as constitutive androstane receptor (CAR), through a crosstalk that in turn orchestrates a complex network of responses. Thus, besides regulating DMETs, PXR signaling is involved in both liver damage progression and repair and in the neoplastic transition to hepatocellular carcinoma. We here summarize the present knowledge about PXR expression and function in chronic liver diseases characterized by different etiologies and clinical outcome, focusing on the molecular pathways involved in PXR activity. Although many molecular details of these finely tuned networks still need to be fully understood, we conclude that PXR and its modulation could represent a promising pharmacological target for the identification of novel therapeutical approaches to chronic liver diseases.
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15
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Schneider M, Delfosse V, Gelin M, Grimaldi M, Granell M, Heriaud L, Pons JL, Cohen Gonsaud M, Balaguer P, Bourguet W, Labesse G. Structure-Based and Knowledge-Informed Design of B-Raf Inhibitors Devoid of Deleterious PXR Binding. J Med Chem 2021; 65:1552-1566. [PMID: 34958586 DOI: 10.1021/acs.jmedchem.1c01354] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Dabrafenib is an anticancer drug currently used in the clinics, alone or in combination. However, dabrafenib was recently shown to potently activate the human nuclear receptor pregnane X receptor (PXR). PXR activation increases the clearance of various chemicals and drugs, including dabrafenib itself. It may also enhance cell proliferation and tumor aggressiveness. Therefore, there is a need for rational design of a potent protein kinase B-Raf inhibitor devoid of binding to the secondary target PXR and resisting rapid metabolism. By determining the crystal structure of dabrafenib bound to PXR and analyzing its mode of binding to both PXR and its primary target, B-Raf-V600E, we were able to derive new compounds with nanomolar activity against B-Raf and no detectable affinity for PXR. The crystal structure of B-Raf in complex with our lead compound revealed a subdomain swapping of the activation loop with potentially important functional implications for a prolonged inhibition of B-Raf-V600E.
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Affiliation(s)
- Melanie Schneider
- Centre de Biologie Structurale (CBS), CNRS, INSERM, Univ Montpellier, F-34090 Montpellier, France
| | - Vanessa Delfosse
- Centre de Biologie Structurale (CBS), CNRS, INSERM, Univ Montpellier, F-34090 Montpellier, France
| | - Muriel Gelin
- Centre de Biologie Structurale (CBS), CNRS, INSERM, Univ Montpellier, F-34090 Montpellier, France
| | - Marina Grimaldi
- Institut de Recherche en Cancérologie de Montpellier (IRCM), INSERM, Univ Montpellier, F-34090 Montpellier, France
| | - Meritxell Granell
- Centre de Biologie Structurale (CBS), CNRS, INSERM, Univ Montpellier, F-34090 Montpellier, France
| | - Laurène Heriaud
- Centre de Biologie Structurale (CBS), CNRS, INSERM, Univ Montpellier, F-34090 Montpellier, France
| | - Jean-Luc Pons
- Centre de Biologie Structurale (CBS), CNRS, INSERM, Univ Montpellier, F-34090 Montpellier, France
| | - Martin Cohen Gonsaud
- Centre de Biologie Structurale (CBS), CNRS, INSERM, Univ Montpellier, F-34090 Montpellier, France
| | - Patrick Balaguer
- Institut de Recherche en Cancérologie de Montpellier (IRCM), INSERM, Univ Montpellier, F-34090 Montpellier, France
| | - William Bourguet
- Centre de Biologie Structurale (CBS), CNRS, INSERM, Univ Montpellier, F-34090 Montpellier, France
| | - Gilles Labesse
- Centre de Biologie Structurale (CBS), CNRS, INSERM, Univ Montpellier, F-34090 Montpellier, France
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16
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Zhuo LS, Wang MS, Wu FX, Xu HC, Gong Y, Yu ZC, Tian YG, Pang C, Hao GF, Huang W, Yang GF. Discovery of Next-Generation Tropomyosin Receptor Kinase Inhibitors for Combating Multiple Resistance Associated with Protein Mutation. J Med Chem 2021; 64:15503-15514. [PMID: 34668694 DOI: 10.1021/acs.jmedchem.1c01539] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Tropomyosin receptor kinase (TRK) inhibition is an effective therapeutic approach for treatment of a variety of cancers. Despite the use of first-generation TRK inhibitor (TRKI) larotrectinib (1) resulting in significant therapeutic response in patients, acquired resistance develops invariably. The emergence of secondary mutations occurring at the solvent-front, xDFG, and gatekeeper regions of TRK represents a common mechanism for acquired resistance. However, xDFG mutations remain insensitive to second-generation macrocyclic TRKIs selitrectinib (3) and repotrectinib (4) designed to overcome the resistance mediated by solvent-front and gatekeeper mutations. Here, we report the structure-based drug design and discovery of a next-generation TRKI. The structure-activity relationship studies culminated in the identification of a promising drug candidate 8 that showed excellent in vitro potency on a panel of TRK mutants, especially TRKAG667C in the xDFG motif, and improved in vivo efficacy than 1 and 3 in TRK wild-type and mutant fusion-driven tumor xenograft models, respectively.
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Affiliation(s)
- Lin-Sheng Zhuo
- Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, International Joint Research Center for Intelligent Biosensor Technology and Health, College of Chemistry, Central China Normal University, Wuhan 430079, P. R. China
| | - Ming-Shu Wang
- Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, International Joint Research Center for Intelligent Biosensor Technology and Health, College of Chemistry, Central China Normal University, Wuhan 430079, P. R. China
| | - Feng-Xu Wu
- Hubei Key Laboratory of Wudang Local Chinese Medicine Research, School of Pharmaceutical Sciences, Hubei University of Medicine, Hubei 442000, P. R. China
| | - Hong-Chuang Xu
- Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, International Joint Research Center for Intelligent Biosensor Technology and Health, College of Chemistry, Central China Normal University, Wuhan 430079, P. R. China
| | - Yi Gong
- Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, International Joint Research Center for Intelligent Biosensor Technology and Health, College of Chemistry, Central China Normal University, Wuhan 430079, P. R. China
| | - Zhi-Cheng Yu
- Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, International Joint Research Center for Intelligent Biosensor Technology and Health, College of Chemistry, Central China Normal University, Wuhan 430079, P. R. China
| | - Yan-Guang Tian
- Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, International Joint Research Center for Intelligent Biosensor Technology and Health, College of Chemistry, Central China Normal University, Wuhan 430079, P. R. China
| | - Chao Pang
- Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, International Joint Research Center for Intelligent Biosensor Technology and Health, College of Chemistry, Central China Normal University, Wuhan 430079, P. R. China
| | - Ge-Fei Hao
- Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, International Joint Research Center for Intelligent Biosensor Technology and Health, College of Chemistry, Central China Normal University, Wuhan 430079, P. R. China
| | - Wei Huang
- Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, International Joint Research Center for Intelligent Biosensor Technology and Health, College of Chemistry, Central China Normal University, Wuhan 430079, P. R. China
| | - Guang-Fu Yang
- Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, International Joint Research Center for Intelligent Biosensor Technology and Health, College of Chemistry, Central China Normal University, Wuhan 430079, P. R. China
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17
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Subbaiah MAM, Meanwell NA. Bioisosteres of the Phenyl Ring: Recent Strategic Applications in Lead Optimization and Drug Design. J Med Chem 2021; 64:14046-14128. [PMID: 34591488 DOI: 10.1021/acs.jmedchem.1c01215] [Citation(s) in RCA: 165] [Impact Index Per Article: 55.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The benzene moiety is the most prevalent ring system in marketed drugs, underscoring its historic popularity in drug design either as a pharmacophore or as a scaffold that projects pharmacophoric elements. However, introspective analyses of medicinal chemistry practices at the beginning of the 21st century highlighted the indiscriminate deployment of phenyl rings as an important contributor to the poor physicochemical properties of advanced molecules, which limited their prospects of being developed into effective drugs. This Perspective deliberates on the design and applications of bioisosteric replacements for a phenyl ring that have provided practical solutions to a range of developability problems frequently encountered in lead optimization campaigns. While the effect of phenyl ring replacements on compound properties is contextual in nature, bioisosteric substitution can lead to enhanced potency, solubility, and metabolic stability while reducing lipophilicity, plasma protein binding, phospholipidosis potential, and inhibition of cytochrome P450 enzymes and the hERG channel.
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Affiliation(s)
- Murugaiah A M Subbaiah
- Department of Medicinal Chemistry, Biocon-Bristol Myers Squibb Research and Development Centre, Biocon Park, Bommasandra IV Phase, Jigani Link Road, Bangalore, Karnataka 560099, India
| | - Nicholas A Meanwell
- Department of Small Molecule Drug Discovery, Bristol Myers Squibb Research and Early Development, P.O. Box 4000, Princeton, New Jersey 08543-4000, United States
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18
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Aicher TD, Van Huis CA, Hurd AR, Skalitzky DJ, Taylor CB, Beleh OM, Glick G, Toogood PL, Yang B, Zheng T, Huo C, Gao J, Qiao C, Tian X, Zhang J, Demock K, Hao LY, Lesch CA, Morgan RW, Moisan J, Wang Y, Scatina J, Paulos CM, Zou W, Carter LL, Hu X. Discovery of LYC-55716: A Potent, Selective, and Orally Bioavailable Retinoic Acid Receptor-Related Orphan Receptor-γ (RORγ) Agonist for Use in Treating Cancer. J Med Chem 2021; 64:13410-13428. [PMID: 34499493 DOI: 10.1021/acs.jmedchem.1c00731] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Retinoic acid receptor-related orphan receptor γ (RORc, RORγ, or NR1F3) is the nuclear receptor master transcription factor that drives the function and development of IL-17-producing T helper cells (Th17), cytotoxic T cells (Tc17), and subsets of innate lymphoid cells. Activation of RORγ+ T cells in the tumor microenvironment is hypothesized to render immune infiltrates more effective at countering tumor growth. To test this hypothesis, a family of benzoxazines was optimized to provide LYC-55716 (37c), a potent, selective, and orally bioavailable small-molecule RORγ agonist. LYC-55716 decreases tumor growth and enhances survival in preclinical tumor models and was nominated as a clinical development candidate for evaluation in patients with solid tumors.
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Affiliation(s)
- Thomas D Aicher
- Department of Chemistry, Lycera Corp., 1350 Highland Drive, Suite A, Ann Arbor, Michigan 48108, United States
| | - Chad A Van Huis
- Department of Chemistry, Lycera Corp., 1350 Highland Drive, Suite A, Ann Arbor, Michigan 48108, United States
| | - Alexander R Hurd
- Department of Chemistry, Lycera Corp., 1350 Highland Drive, Suite A, Ann Arbor, Michigan 48108, United States
| | - Donald J Skalitzky
- Department of Chemistry, Lycera Corp., 1350 Highland Drive, Suite A, Ann Arbor, Michigan 48108, United States
| | - Clarke B Taylor
- Department of Chemistry, Lycera Corp., 1350 Highland Drive, Suite A, Ann Arbor, Michigan 48108, United States
| | - Omar M Beleh
- Department of Chemistry, Lycera Corp., 1350 Highland Drive, Suite A, Ann Arbor, Michigan 48108, United States
| | - Gary Glick
- Chief Scientific Officer, Lycera Corp., 1350 Highland Drive, Suite A, Ann Arbor, Michigan 48108, United States
| | - Peter L Toogood
- Department of Chemistry, Lycera Corp., 1350 Highland Drive, Suite A, Ann Arbor, Michigan 48108, United States
| | - Bing Yang
- Department of Chemistry, Pharmaron Beijing, Co. Ltd., Beijing 100176, P. R. China
| | - Tao Zheng
- Department of Chemistry, Pharmaron Beijing, Co. Ltd., Beijing 100176, P. R. China
| | - Changxin Huo
- Department of Chemistry, Pharmaron Beijing, Co. Ltd., Beijing 100176, P. R. China
| | - Jie Gao
- Department of Chemistry, Pharmaron Beijing, Co. Ltd., Beijing 100176, P. R. China
| | - Chenxi Qiao
- Department of Chemistry, Pharmaron Beijing, Co. Ltd., Beijing 100176, P. R. China
| | - Xiaolong Tian
- Department of Chemistry, Pharmaron Beijing, Co. Ltd., Beijing 100176, P. R. China
| | - Junping Zhang
- Department of Chemistry, Pharmaron Beijing, Co. Ltd., Beijing 100176, P. R. China
| | - Kellie Demock
- Department of Biology, Lycera Corp., 1350 Highland Drive, Suite A, Ann Arbor, Michigan 48108, United States
| | - Ling-Yang Hao
- Department of Biology, Lycera Corp., 1350 Highland Drive, Suite A, Ann Arbor, Michigan 48108, United States
| | - Charles A Lesch
- Department of Biology, Lycera Corp., 1350 Highland Drive, Suite A, Ann Arbor, Michigan 48108, United States
| | - Rodney W Morgan
- Department of Biology, Lycera Corp., 1350 Highland Drive, Suite A, Ann Arbor, Michigan 48108, United States
| | - Jacques Moisan
- Department of Biology, Lycera Corp., 1350 Highland Drive, Suite A, Ann Arbor, Michigan 48108, United States
| | - Yahong Wang
- Department of Biology, Lycera Corp., 1350 Highland Drive, Suite A, Ann Arbor, Michigan 48108, United States
| | - JoAnn Scatina
- Department of Preclinical Development, Lycera Corp., 620 Germantown Pike, Plymouth Meeting, Pennsylvania 19462, United States
| | - Chrystal M Paulos
- Hollings Cancer Center, Medical University of South Carolina, 173 Ashley Avenue, MSC 509, Room 203, Charleston, South Carolina 29425, United States
| | - Weiping Zou
- School of Medicine, Department of Surgery, University of Michigan, 2101 Taubman Center, 1500 E. Medical Center Drive, Ann Arbor, Michigan 48109, United States
| | - Laura L Carter
- Department of Biology, Lycera Corp., 1350 Highland Drive, Suite A, Ann Arbor, Michigan 48108, United States
| | - Xiao Hu
- Department of Biology, Lycera Corp., 1350 Highland Drive, Suite A, Ann Arbor, Michigan 48108, United States
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