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Liu Z, Wong ILK, Sang J, Liu F, Yan CSW, Kan JWY, Chan TH, Chow LMC. Identification of Binding Sites in the Nucleotide-Binding Domain of P-Glycoprotein for a Potent and Nontoxic Modulator, the Amine-Containing Monomeric Flavonoid FM04. J Med Chem 2023; 66:6160-6183. [PMID: 37098275 DOI: 10.1021/acs.jmedchem.2c02005] [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: 04/27/2023]
Abstract
We have previously discovered an amine-containing flavonoid monomer FM04 as a potent P-glycoprotein (P-gp) inhibitor (EC50 = 83 nM). Here, a series of photoactive FM04 analogues were synthesized and used together with liquid chromatography-tandem mass spectrometry (LC-MS/MS) to identify the FM04-binding sites on P-gp. Point mutations around the photo-crosslinked sites were made for verification. Together with the results from mutational studies, molecular docking, and molecular dynamics simulations, it was found that FM04 can interact with Q1193 and I1115 in the nucleotide-binding domain 2 (NBD2) of human P-gp. It was proposed that FM04 can inhibit P-gp in 2 novel mechanisms. FM04 can either bind to (1) Q1193, followed by interacting with the functionally critical residues H1195 and T1226 or (2) I1115 (a functionally critical residue itself), disrupting the R262-Q1081-Q1118 interaction pocket and uncoupling ICL2-NBD2 interaction and thereby inhibiting P-gp. Q1118 would subsequently be pushed to the ATP-binding site and stimulate ATPase.
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Affiliation(s)
- Zhen Liu
- Department of Applied Biology and Chemical Technology, State Key Laboratory of Chemical Biology and Drug Discovery, The Hong Kong Polytechnic University, Hong Kong SAR, China
| | - Iris L K Wong
- Department of Applied Biology and Chemical Technology, State Key Laboratory of Chemical Biology and Drug Discovery, The Hong Kong Polytechnic University, Hong Kong SAR, China
| | - Jingcheng Sang
- College of Biotechnology, Tianjin University of Science & Technology, Tianjin 300457, China
| | - Fufeng Liu
- Department of Applied Biology and Chemical Technology, State Key Laboratory of Chemical Biology and Drug Discovery, The Hong Kong Polytechnic University, Hong Kong SAR, China
- College of Biotechnology, Tianjin University of Science & Technology, Tianjin 300457, China
| | - Clare S W Yan
- Department of Applied Biology and Chemical Technology, State Key Laboratory of Chemical Biology and Drug Discovery, The Hong Kong Polytechnic University, Hong Kong SAR, China
| | - Jason W Y Kan
- Department of Applied Biology and Chemical Technology, State Key Laboratory of Chemical Biology and Drug Discovery, The Hong Kong Polytechnic University, Hong Kong SAR, China
| | - Tak Hang Chan
- Department of Applied Biology and Chemical Technology, State Key Laboratory of Chemical Biology and Drug Discovery, The Hong Kong Polytechnic University, Hong Kong SAR, China
- Department of Chemistry, McGill University, Montreal, Quebec H3A 2K6, Canada
| | - Larry M C Chow
- Department of Applied Biology and Chemical Technology, State Key Laboratory of Chemical Biology and Drug Discovery, The Hong Kong Polytechnic University, Hong Kong SAR, China
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Teodori E, Braconi L, Manetti D, Romanelli MN, Dei S. The Tetrahydroisoquinoline Scaffold in ABC Transporter Inhibitors that Act as Multidrug Resistance (MDR) Reversers. Curr Top Med Chem 2022; 22:2535-2569. [PMID: 36284399 DOI: 10.2174/1568026623666221025111528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 08/08/2022] [Accepted: 09/27/2022] [Indexed: 01/20/2023]
Abstract
BACKGROUND The failure of anticancer chemotherapy is often due to the development of resistance to a variety of anticancer drugs. This phenomenon is called multidrug resistance (MDR) and is related to the overexpression of ABC transporters, such as P-glycoprotein, multidrug resistance- associated protein 1 and breast cancer resistance protein. Over the past few decades, several ABC protein modulators have been discovered and studied as a possible approach to evade MDR and increase the success of anticancer chemotherapy. Nevertheless, the co-administration of pump inhibitors with cytotoxic drugs, which are substrates of the transporters, does not appear to be associated with an improvement in the therapeutic efficacy of antitumor agents. However, more recently discovered MDR reversing agents, such as the two tetrahydroisoquinoline derivatives tariquidar and elacridar, are characterized by high affinity towards the ABC proteins and by reduced negative properties. Consequently, many analogs of these two derivatives have been synthesized, with the aim of optimizing their MDR reversal properties. OBJECTIVE This review aims to describe the MDR modulators carrying the tetraidroisoquinoline scaffold reported in the literature in the period 2009-2021, highlighting the structural characteristics that confer potency and/or selectivity towards the three ABC transport proteins. RESULTS AND CONCLUSION Many compounds have been synthesized in the last twelve years showing interesting properties, both in terms of potency and selectivity. Although clear structure-activity relationships can be drawn only by considering strictly related compounds, some of the compounds reviewed could be promising starting points for the design of new ABC protein inhibitors.
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Affiliation(s)
- Elisabetta Teodori
- Department of Neuroscience, Psychology, Drug Research and Child's Health, Section of Pharmaceutical and Nutraceutical Sciences, University of Florence, via Ugo Schiff 6, 50019, Sesto Fiorentino (FI), Italy
| | - Laura Braconi
- Department of Neuroscience, Psychology, Drug Research and Child's Health, Section of Pharmaceutical and Nutraceutical Sciences, University of Florence, via Ugo Schiff 6, 50019, Sesto Fiorentino (FI), Italy
| | - Dina Manetti
- Department of Neuroscience, Psychology, Drug Research and Child's Health, Section of Pharmaceutical and Nutraceutical Sciences, University of Florence, via Ugo Schiff 6, 50019, Sesto Fiorentino (FI), Italy
| | - Maria Novella Romanelli
- Department of Neuroscience, Psychology, Drug Research and Child's Health, Section of Pharmaceutical and Nutraceutical Sciences, University of Florence, via Ugo Schiff 6, 50019, Sesto Fiorentino (FI), Italy
| | - Silvia Dei
- Department of Neuroscience, Psychology, Drug Research and Child's Health, Section of Pharmaceutical and Nutraceutical Sciences, University of Florence, via Ugo Schiff 6, 50019, Sesto Fiorentino (FI), Italy
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Wu X, Yin C, Ma J, Chai S, Zhang C, Yao S, Kadioglu O, Efferth T, Ye Y, To KKW, Lin G. Polyoxypregnanes as safe, potent, and specific ABCB1-inhibitory pro-drugs to overcome multidrug resistance in cancer chemotherapy in vitro and in vivo. Acta Pharm Sin B 2021; 11:1885-1902. [PMID: 34386326 PMCID: PMC8343194 DOI: 10.1016/j.apsb.2020.12.021] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 10/22/2020] [Accepted: 12/29/2020] [Indexed: 12/31/2022] Open
Abstract
Multidrug resistance (MDR) mediated by ATP binding cassette subfamily B member 1 (ABCB1) is significantly hindering effective cancer chemotherapy. However, currently, no ABCB1-inhibitory drugs have been approved to treat MDR cancer clinically, mainly due to the inhibitor specificity, toxicity, and drug interactions. Here, we reported that three polyoxypregnanes (POPs) as the most abundant constituents of Marsdenia tenacissima (M. tenacissima) were novel ABCB1-modulatory pro-drugs, which underwent intestinal microbiota-mediated biotransformation in vivo to generate active metabolites. The metabolites at non-toxic concentrations restored chemosensitivity in ABCB1-overexpressing cancer cells via inhibiting ABCB1 efflux activity without changing ABCB1 protein expression, which were further identified as specific non-competitive inhibitors of ABCB1 showing multiple binding sites within ABCB1 drug cavity. These POPs did not exhibit ABCB1/drug metabolizing enzymes interplay, and their repeated administration generated predictable pharmacokinetic interaction with paclitaxel without obvious toxicity in vivo. We further showed that these POPs enhanced the accumulation of paclitaxel in tumors and overcame ABCB1-mediated chemoresistance. The results suggested that these POPs had the potential to be developed as safe, potent, and specific pro-drugs to reverse ABCB1-mediated MDR. Our work also provided scientific evidence for the use of M. tenacissima in combinational chemotherapy.
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Key Words
- ABC, ATP-binding cassette
- ABCB1
- ABCB1, ATP binding cassette subfamily B member 1
- ABCC1, ATP binding cassette subfamily C member 1
- ABCG2, ATP binding cassette subfamily G member 2
- ATF3, activating transcription factor 3
- AUC0–∞, area under plasma concentration vs. time curve
- BBB, blood–brain barrier
- BHI, brain heart infusion
- CL, clearance
- CYP, cytochrome P450 isozyme
- Cmax, peak concentration
- Combination chemotherapy
- Dox, doxorubicin
- ECL, electrochemiluminescence
- EVOM, epithelial tissue voltohmmeter
- F, bioavailability
- FBS, fetal bovine serum
- GAPDH, glyceraldehyde-3-phosphate dehydrogenase
- H&E, hematoxylin and eosin
- HBSS, Hankʹs balanced salt solution
- IC50, half maximal inhibitory concentration
- LBE, lowest binding energy
- LC–MS, liquid chromatography coupled with mass spectrometry
- M. tenacissima, Marsdenia tenacissima
- MDR, multidrug resistance
- MDR1a, multidrug resistance protein 1a
- MRT, mean residence time
- Marsdenia tenacissima
- Multidrug resistance
- N.A., not applicable
- N.D., not detected
- NADPH, reduced nicotinamide adenine dinucleotide phosphate
- NMPA, National Medical Products Administration
- PBS, phosphate buffer saline
- PCR, polymerase chain reaction
- PE, phycoerythrin
- PI, propidium iodide
- POP, polyoxypregnane
- PXR, pregnane X receptor
- Papp, apparent permeability
- Polyoxypregnane
- SD, standard derivation
- SDS-PAGE, sodium dodecyl sulfate-polyacrylamide gel electrophoresis
- TEER, transepithelial electrical resistance
- Tmax, time for peak concentration
- UIC-2, mouse monoclonal ABCB1 antibody
- Vd, volume of distribution
- qPCR, quantitative PCR
- t1/2, elimination half-life
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Cseke A, Schwarz T, Jain S, Decker S, Vogl K, Urban E, Ecker GF. Propafenone analogue with additional H-bond acceptor group shows increased inhibitory activity on P-glycoprotein. Arch Pharm (Weinheim) 2020; 353:e1900269. [PMID: 31917466 DOI: 10.1002/ardp.201900269] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 11/21/2019] [Accepted: 12/08/2019] [Indexed: 11/10/2022]
Abstract
P-glycoprotein (P-gp) is an ATP-dependent efflux pump that has a marked impact on the absorption, distribution, and excretion of therapeutic drugs. As P-gp inhibition can result in drug-drug interactions and altered drug bioavailability, identifying molecular properties that are linked to inhibition is of great interest in drug development. In this study, we combined chemical synthesis, in vitro testing, quantitative structure-activity relationship analysis, and docking studies to investigate the role of hydrogen bond (H-bond) donor/acceptor properties in transporter-ligand interaction. In a previous work, it has been shown that propafenone analogs with a 4-hydroxy-4-piperidine moiety exhibit a generally 10-fold higher P-gp inhibitory activity than expected based on their lipophilicity. Here, we specifically expanded the data set by introducing substituents at position 4 of the 4-phenylpiperidine moiety to assess the importance of H-bond donor/acceptor features in this region. The results suggest that indeed an H-bond acceptor, such as hydroxy and methoxy, increases the affinity by forming a H-bond with Tyr310.
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Affiliation(s)
- Anna Cseke
- Department of Pharmaceutical Chemistry, University of Vienna, Vienna, Austria
| | - Theresa Schwarz
- Department of Pharmaceutical Chemistry, University of Vienna, Vienna, Austria
| | - Sankalp Jain
- Department of Pharmaceutical Chemistry, University of Vienna, Vienna, Austria.,National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD, USA
| | - Simon Decker
- Department of Pharmaceutical Chemistry, University of Vienna, Vienna, Austria
| | - Kerstin Vogl
- Department of Pharmaceutical Chemistry, University of Vienna, Vienna, Austria
| | - Ernst Urban
- Department of Pharmaceutical Chemistry, University of Vienna, Vienna, Austria
| | - Gerhard F Ecker
- Department of Pharmaceutical Chemistry, University of Vienna, Vienna, Austria
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5
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Novel Heat Shock Protein 90 Inhibitors Suppress P-Glycoprotein Activity and Overcome Multidrug Resistance in Cancer Cells. Int J Mol Sci 2019; 20:ijms20184575. [PMID: 31527404 PMCID: PMC6770006 DOI: 10.3390/ijms20184575] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 08/31/2019] [Accepted: 09/06/2019] [Indexed: 12/25/2022] Open
Abstract
Heat Shock Protein 90 (Hsp90) chaperone interacts with a broad range of client proteins involved in cancerogenesis and cancer progression. However, Hsp90 inhibitors were unsuccessful as anticancer agents due to their high toxicity, lack of selectivity against cancer cells and extrusion by membrane transporters responsible for multidrug resistance (MDR) such as P-glycoprotein (P-gp). Recognizing the potential of new compounds to inhibit P-gp function and/or expression is essential in the search for effective anticancer drugs. Eleven Hsp90 inhibitors containing an isoxazolonaphtoquinone core were synthesized and evaluated in two MDR models comprised of sensitive and corresponding resistant cancer cells with P-gp overexpression (human non-small cell lung carcinoma and colorectal adenocarcinoma). We investigated the effect of Hsp90 inhibitors on cell growth inhibition, P-gp activity and P-gp expression. Structure-activity relationship analysis was performed in respect to cell growth and P-gp inhibition. Compounds 5, 7, and 9 directly interacted with P-gp and inhibited its ATPase activity. Their potential P-gp binding site was identified by molecular docking studies. In addition, these compounds downregulated P-gp expression in MDR colorectal carcinoma cells, showed good relative selectivity towards cancer cells, while compound 5 reversed resistance to doxorubicin and paclitaxel in concentration-dependent manner. Therefore, compounds 5, 7 and 9 could be promising candidates for treating cancers with P-gp overexpression.
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Wei Y, Xia H, Zhang F, Wang K, Luo P, Wu Y, Liu S. Theranostic Nanoprobe Mediated Simultaneous Monitoring and Inhibition of P-Glycoprotein Potentiating Multidrug-Resistant Cancer Therapy. Anal Chem 2019; 91:11200-11208. [DOI: 10.1021/acs.analchem.9b02118] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Yuanqing Wei
- Jiangsu Engineering Laboratory of Smart Carbon-Rich Materials and Device, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China
| | - Hongping Xia
- Department of Pathology, School of Basic Medical Sciences & The Affiliated Sir Run Run Hospital, Nanjing Medical University, Nanjing 21116, China
| | - Fen Zhang
- Jiangsu Engineering Laboratory of Smart Carbon-Rich Materials and Device, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China
| | - Kan Wang
- Jiangsu Engineering Laboratory of Smart Carbon-Rich Materials and Device, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China
| | - Peicheng Luo
- Jiangsu Engineering Laboratory of Smart Carbon-Rich Materials and Device, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China
| | - Yafeng Wu
- Jiangsu Engineering Laboratory of Smart Carbon-Rich Materials and Device, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China
| | - Songqin Liu
- Jiangsu Engineering Laboratory of Smart Carbon-Rich Materials and Device, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China
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Xing J, Mei H, Huang S, Zhang D, Pan X. An Energetically Favorable Ligand Entrance Gate of a Multidrug Transporter Revealed by Partial Nudged Elastic Band Simulations. Comput Struct Biotechnol J 2019; 17:319-323. [PMID: 30899446 PMCID: PMC6406077 DOI: 10.1016/j.csbj.2019.02.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 02/14/2019] [Accepted: 02/15/2019] [Indexed: 11/08/2022] Open
Abstract
P-glycoprotein (P-gp) is a multidrug transporter, which harnesses the chemical energy of ATP to power the efflux of diverse chemotherapeutics out of cells and thus contributes to the development of multidrug resistance (MDR) in cancer. It has been proved that the ligand-binding pocket of P-gp is located at the transmembrane domains (TMDs). However, the access of ligands into the binding pocket remains to be elucidated, which definitely hinder the development of P-gp inhibitors. Herein, the access pathways of a well-known substrate rhodamine-123 and a cyclopeptide inhibitor QZ-Leu were characterized by time-independent partial nudged elastic band (PNEB) simulations. The decreasing free energies along the PNEB-optimized access pathway indicated that TM4/6 cleft may be an energetically favorable entrance gate for ligand entry into the binding pocket of P-gp. The results can be reconciled with a range of experimental studies, further corroborating the reliability of the gate revealed by computational simulations. Our atomic level description of the ligand access pathway provides valuable insights into the gating mechanism for drug uptake and transport by P-gp and other multidrug transporters. P-gp contributes to the development of multidrug resistance in cancer. The entrance of drugs into P-gp binding pocket has yet to be elucidated. An energetically favorable entrance gate was revealed by PNEB simulations. The computational results were reconciled with the experimental data. The atomic simulations provide insights into the gating mechanism of P-gp.
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Affiliation(s)
- Juan Xing
- Key Laboratory of Biorheological Science and Technology (Ministry of Education), College of Bioengineering, Chongqing University, Chongqing 400045, China.,Department of Pathophysiology, College of Basic Medical Science, Southwest Medical University, Luzhou, Sichuan 646000, China
| | - Hu Mei
- Key Laboratory of Biorheological Science and Technology (Ministry of Education), College of Bioengineering, Chongqing University, Chongqing 400045, China
| | - ShuHeng Huang
- Key Laboratory of Biorheological Science and Technology (Ministry of Education), College of Bioengineering, Chongqing University, Chongqing 400045, China
| | - Duo Zhang
- Key Laboratory of Biorheological Science and Technology (Ministry of Education), College of Bioengineering, Chongqing University, Chongqing 400045, China
| | - XianChao Pan
- Key Laboratory of Biorheological Science and Technology (Ministry of Education), College of Bioengineering, Chongqing University, Chongqing 400045, China.,Department of Medicinal Chemistry, College of Pharmacy, Southwest Medical University, Luzhou, Sichuan 646000, China
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Wu CP, Murakami M, Hsiao SH, Liu TC, Yeh N, Li YQ, Hung TH, Wu YS, Ambudkar SV. SIS3, a specific inhibitor of Smad3 reverses ABCB1- and ABCG2-mediated multidrug resistance in cancer cell lines. Cancer Lett 2018; 433:259-272. [PMID: 30026175 DOI: 10.1016/j.canlet.2018.07.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2018] [Revised: 06/29/2018] [Accepted: 07/03/2018] [Indexed: 01/05/2023]
Abstract
One of the major challenges in cancer chemotherapy is the development of multidrug resistance phenomenon attributed to the overexpression of ATP-binding cassette (ABC) transporter ABCB1 or ABCG2 in cancer cells. Therefore, re-sensitizing MDR cancer cells to chemotherapy by directly inhibiting the activity of ABC transporters has clinical relevance. Unfortunately, previous attempts of developing clinically applicable synthetic inhibitors have failed, mostly due to problems associated with toxicity and unforeseen drug-drug interactions. An alternative approach is by repositioning drugs with known pharmacological properties as modulators of ABCB1 and ABCG2. In this study, we discovered that the transport function of ABCB1 and ABCG2 is strongly inhibited by SIS3, a specific inhibitor of Smad3. More importantly, SIS3 enhances drug-induced apoptosis and resensitizes ABCB1- and ABCG2-overexpressing cancer cells to chemotherapeutic drugs at non-toxic concentrations. These findings are further supported by ATPase assays and by a docking analysis of SIS3 in the drug-binding pockets of ABCB1 and ABCG2. In summary, we revealed an additional action of SIS3 that re-sensitizes MDR cancer cells and a combination therapy with this drug and other chemotherapeutic agents may be beneficial for patients with MDR tumors.
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Affiliation(s)
- Chung-Pu Wu
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan; Department of Physiology and Pharmacology, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan; Department of Neurosurgery, Chang Gung Memorial Hospital, Linkou, Taiwan.
| | - Megumi Murakami
- Laboratory of Cell Biology, CCR, NCI, NIH, Bethesda, United States.
| | - Sung-Han Hsiao
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan.
| | - Te-Chun Liu
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan.
| | - Ni Yeh
- Department of Chemistry, Tunghai University, Taichung, Taiwan.
| | - Yan-Qing Li
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan; Department of Physiology and Pharmacology, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan.
| | - Tai-Ho Hung
- Department of Chinese Medicine, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan; Department of Obstetrics and Gynecology, Taipei Chang Gung Memorial Hospital, Taipei, Taiwan.
| | - Yu-Shan Wu
- Department of Chemistry, Tunghai University, Taichung, Taiwan.
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9
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Abstract
The ATP binding cassette transporter ABCB1 (also termed P-glycoprotein) is a physiologically essential multidrug efflux transporter of key relevance to biomedicine. Here, we report the conformational trapping and structural analysis of ABCB1 in complex with the antigen-binding fragment of UIC2, a human ABCB1-specific inhibitory antibody, and zosuquidar, a third-generation ABCB1 inhibitor. The structures outline key features underlining specific ABCB1 inhibition by antibodies and small molecules, including a dual mode of inhibitor binding in a fully occluded ABCB1 cavity. Finally, our analysis sheds light on the conformational transitions undergone by the transporter to reach the inhibitor-bound state. The multidrug transporter ABCB1 (P-glycoprotein) is an ATP-binding cassette transporter that has a key role in protecting tissues from toxic insult and contributes to multidrug extrusion from cancer cells. Here, we report the near-atomic resolution cryo-EM structure of nucleotide-free ABCB1 trapped by an engineered disulfide cross-link between the nucleotide-binding domains (NBDs) and bound to the antigen-binding fragment of the human-specific inhibitory antibody UIC2 and to the third-generation ABCB1 inhibitor zosuquidar. Our structure reveals the transporter in an occluded conformation with a central, enclosed, inhibitor-binding pocket lined by residues from all transmembrane (TM) helices of ABCB1. The pocket spans almost the entire width of the lipid membrane and is occupied exclusively by two closely interacting zosuquidar molecules. The external, conformational epitope facilitating UIC2 binding is also visualized, providing a basis for its inhibition of substrate efflux. Additional cryo-EM structures suggest concerted movement of TM helices from both halves of the transporters associated with closing the NBD gap, as well as zosuquidar binding. Our results define distinct recognition interfaces of ABCB1 inhibitory agents, which may be exploited for therapeutic purposes.
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Yi X, Zhao D, Zhang Q, Xu J, Yuan G, Zhuo R, Li F. Preparation of multilocation reduction-sensitive core crosslinked folate-PEG-coated micelles for rapid release of doxorubicin and tariquidar to overcome drug resistance. NANOTECHNOLOGY 2017; 28:085603. [PMID: 28055982 DOI: 10.1088/1361-6528/aa5715] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Herein, we prepared folate-targeting core crosslinked polymeric micelles (CCL/FA) containing multiple disulfide bonds located at the interface and core of the micelles to co-deliver doxorubicin (DOX) and the P-glycoprotein (P-gp) inhibitor tariquidar (TQR) for reversing drug resistance. The stability and redox-responsive behavior of the CCL/FA micelles was evaluated through the changes in morphology, molecular weight and hydrodynamic size. On the one hand, the micelles possessed good stability, which led to the suppression of drug release from the CCL micelles in the physiological environment. On the other hand, under reductive conditions, the CCL micelles collapsed rapidly and accelerated drug release markedly. In vitro cytotoxicity measurements, combined with confocal laser scanning microscopy (CLSM) and flow cytometry, confirmed that the dual-drug-loaded micelles exhibited obviously higher cytotoxicity to MCF-7/ADR-resistant cells than free DOX · HCl, single-drug loaded CCL micelles and nontargeted CCL micelles. The results imply that co-delivering DOX and TQR by CCL/FA micelles may be a promising way of overcoming multidrug resistance in tumor treatments.
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Affiliation(s)
- Xiaoqing Yi
- Key Laboratory of Biomedical Polymers of Ministry of Education, College of Chemistry and Molecular Science, Wuhan University, Wuhan, 430072, People's Republic of China
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11
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Li J, Liu Y, Zhang J, Yu X, Wang X, Zhao L. Effects of resveratrol on P-glycoprotein and cytochrome P450 3A in vitro and on pharmacokinetics of oral saquinavir in rats. DRUG DESIGN DEVELOPMENT AND THERAPY 2016; 10:3699-3706. [PMID: 27895462 PMCID: PMC5117956 DOI: 10.2147/dddt.s118723] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Background The intestinal cytochrome P450 3A (CYP 3A) and P-glycoprotein (P-gp) present a barrier to the oral absorption of saquinavir (SQV). Resveratrol (RESV) has been indicated to have modulatory effects on P-gp and CYP 3A. Therefore, this study was to investigate the effects of RESV on P-gp and CYP 3A activities in vitro and in vivo on oral SQV pharmacokinetics in rats. Methods In vitro, intestinal microsomes were used to evaluate RESV effect on CYP 3A-mediated metabolism of SQV; MDR1-expressing Madin–Darby canine kidney (MDCKII-MDR1) cells were employed to assess the impact of RESV on P-gp-mediated efflux of SQV. In vivo effects were studied using 10 rats randomly assigned to receive oral SQV (30 mg/kg) with or without RESV (20 mg/kg). Serial blood samples were obtained over the following 24 h. Concentrations of SQV in samples were ascertained using high-performance liquid chromatography-tandem mass spectrometry analysis. Results RESV (1–100 μM) enhanced residual SQV (% of control) in a dose-dependent manner after incubation with intestinal microsomes. RESV (1–100 μM) reduced the accumulation of SQV in MDCKII-MDR1 cells in a concentration-dependent manner. A double peaking phenomenon was observed in the plasma SQV profiles in rats. The first peak of plasma SQV concentration was increased, but the second peak was reduced by coadministration with RESV. The mean AUC0–∞ of SQV was slightly decreased, with no statistical significance probably due to the high individual variation. Conclusion RESV can alter the plasma SQV concentration profiles, shorten the Tmax of SQV. RESV might also cause a slight decrease tendency in the SQV bioavailability in rats.
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Affiliation(s)
- Jiapeng Li
- Department of Pharmacy, Beijing Children's Hospital, Capital Medical University; Department of Pharmacy Administration and Clinical Pharmacy, School of Pharmaceutical Sciences, Peking University, Beijing, People's Republic of China
| | - Yang Liu
- Department of Pharmacy Administration and Clinical Pharmacy, School of Pharmaceutical Sciences, Peking University, Beijing, People's Republic of China
| | - Jingru Zhang
- Department of Pharmacy, Beijing Children's Hospital, Capital Medical University; Department of Pharmacy Administration and Clinical Pharmacy, School of Pharmaceutical Sciences, Peking University, Beijing, People's Republic of China
| | - Xiaotong Yu
- Department of Pharmacy, Beijing Children's Hospital, Capital Medical University; Department of Pharmacy Administration and Clinical Pharmacy, School of Pharmaceutical Sciences, Peking University, Beijing, People's Republic of China
| | - Xiaoling Wang
- Department of Pharmacy, Beijing Children's Hospital, Capital Medical University
| | - Libo Zhao
- Department of Pharmacy, Beijing Children's Hospital, Capital Medical University
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12
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Hsiao SH, Lu YJ, Li YQ, Huang YH, Hsieh CH, Wu CP. Osimertinib (AZD9291) Attenuates the Function of Multidrug Resistance-Linked ATP-Binding Cassette Transporter ABCB1 in Vitro. Mol Pharm 2016; 13:2117-25. [PMID: 27169328 DOI: 10.1021/acs.molpharmaceut.6b00249] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The effectiveness of cancer chemotherapy is often circumvented by multidrug resistance (MDR) caused by the overexpression of ATP-binding cassette (ABC) drug transporter ABCB1 (MDR1, P-glycoprotein). Several epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) have been shown previously capable of modulating the function of ABCB1 and reversing ABCB1-mediated MDR in human cancer cells. Furthermore, some TKIs are transported by ABCB1, which results in low oral bioavailability, reduced distribution, and the development of acquired resistance to these TKIs. In this study, we investigated the interaction between ABCB1 and osimertinib, a novel selective, irreversible third-generation EGFR TKI that has recently been approved by the U.S. Food and Drug Administration. We also evaluated the potential impact of ABCB1 on the efficacy of osimertinib in cancer cells, which can present a therapeutic challenge to clinicians in the future. We revealed that although osimertinib stimulates the ATPase activity of ABCB1, overexpression of ABCB1 does not confer resistance to osimertinib. Our results suggest that it is unlikely that the overexpression of ABCB1 can be a major contributor to the development of osimertinib resistance in cancer patients. More significantly, we revealed an additional action of osimertinib that directly inhibits the function of ABCB1 without affecting the expression level of ABCB1, enhances drug-induced apoptosis, and reverses the MDR phenotype in ABCB1-overexpressing cancer cells. Considering that osimertinib is a clinically approved third-generation EGFR TKI, our findings suggest that a combination therapy with osimertinib and conventional anticancer drugs may be beneficial to patients with MDR tumors.
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Affiliation(s)
- Sung-Han Hsiao
- Graduate Institute of Biomedical Sciences, ‡Department of Neurosurgery, Chang Gung Memorial Hospital, §Department of Physiology and Pharmacology, and ⊥Molecular Medicine Research Center, College of Medicine, Chang Gung University , Tao-Yuan 33302, Taiwan.,Graduate Institute of Basic Medical Science and ∥Department of Medical Research, China Medical University Hospital , Taichung 40402, Taiwan
| | - Yu-Jen Lu
- Graduate Institute of Biomedical Sciences, ‡Department of Neurosurgery, Chang Gung Memorial Hospital, §Department of Physiology and Pharmacology, and ⊥Molecular Medicine Research Center, College of Medicine, Chang Gung University , Tao-Yuan 33302, Taiwan.,Graduate Institute of Basic Medical Science and ∥Department of Medical Research, China Medical University Hospital , Taichung 40402, Taiwan
| | - Yan-Qing Li
- Graduate Institute of Biomedical Sciences, ‡Department of Neurosurgery, Chang Gung Memorial Hospital, §Department of Physiology and Pharmacology, and ⊥Molecular Medicine Research Center, College of Medicine, Chang Gung University , Tao-Yuan 33302, Taiwan.,Graduate Institute of Basic Medical Science and ∥Department of Medical Research, China Medical University Hospital , Taichung 40402, Taiwan
| | - Yang-Hui Huang
- Graduate Institute of Biomedical Sciences, ‡Department of Neurosurgery, Chang Gung Memorial Hospital, §Department of Physiology and Pharmacology, and ⊥Molecular Medicine Research Center, College of Medicine, Chang Gung University , Tao-Yuan 33302, Taiwan.,Graduate Institute of Basic Medical Science and ∥Department of Medical Research, China Medical University Hospital , Taichung 40402, Taiwan
| | - Chia-Hung Hsieh
- Graduate Institute of Biomedical Sciences, ‡Department of Neurosurgery, Chang Gung Memorial Hospital, §Department of Physiology and Pharmacology, and ⊥Molecular Medicine Research Center, College of Medicine, Chang Gung University , Tao-Yuan 33302, Taiwan.,Graduate Institute of Basic Medical Science and ∥Department of Medical Research, China Medical University Hospital , Taichung 40402, Taiwan
| | - Chung-Pu Wu
- Graduate Institute of Biomedical Sciences, ‡Department of Neurosurgery, Chang Gung Memorial Hospital, §Department of Physiology and Pharmacology, and ⊥Molecular Medicine Research Center, College of Medicine, Chang Gung University , Tao-Yuan 33302, Taiwan.,Graduate Institute of Basic Medical Science and ∥Department of Medical Research, China Medical University Hospital , Taichung 40402, Taiwan
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13
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Loo TW, Clarke DM. Mapping the Binding Site of the Inhibitor Tariquidar That Stabilizes the First Transmembrane Domain of P-glycoprotein. J Biol Chem 2015; 290:29389-401. [PMID: 26507655 PMCID: PMC4705942 DOI: 10.1074/jbc.m115.695171] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Indexed: 11/26/2022] Open
Abstract
ABC (ATP-binding cassette) transporters are clinically important because drug pumps like P-glycoprotein (P-gp, ABCB1) confer multidrug resistance and mutant ABC proteins are responsible for many protein-folding diseases such as cystic fibrosis. Identification of the tariquidar-binding site has been the subject of intensive molecular modeling studies because it is the most potent inhibitor and corrector of P-gp. Tariquidar is a unique P-gp inhibitor because it locks the pump in a conformation that blocks drug efflux but activates ATPase activity. In silico docking studies have identified several potential tariquidar-binding sites. Here, we show through cross-linking studies that tariquidar most likely binds to sites within the transmembrane (TM) segments located in one wing or at the interface between the two wings (12 TM segments form 2 divergent wings). We then introduced arginine residues at all positions in the 12 TM segments (223 mutants) of P-gp. The rationale was that a charged residue in the drug-binding pocket would disrupt hydrophobic interaction with tariquidar and inhibit its ability to rescue processing mutants or stimulate ATPase activity. Arginines introduced at 30 positions significantly inhibited tariquidar rescue of a processing mutant and activation of ATPase activity. The results suggest that tariquidar binds to a site within the drug-binding pocket at the interface between the TM segments of both structural wings. Tariquidar differed from other drug substrates, however, as it stabilized the first TM domain. Stabilization of the first TM domain appears to be a key mechanism for high efficiency rescue of ABC processing mutants that cause disease.
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Affiliation(s)
- Tip W Loo
- From the Departments of Medicine and Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - David M Clarke
- From the Departments of Medicine and Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
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14
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Pharmacokinetic and pharmacodynamic study of tariquidar (XR9576), a P-glycoprotein inhibitor, in combination with doxorubicin, vinorelbine, or docetaxel in children and adolescents with refractory solid tumors. Cancer Chemother Pharmacol 2015; 76:1273-83. [PMID: 26486517 DOI: 10.1007/s00280-015-2845-1] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2015] [Accepted: 08/02/2015] [Indexed: 02/03/2023]
Abstract
PURPOSE P-glycoprotein (Pgp), an ATP-dependent transport protein, confers multidrug resistance in cancer cells. Tariquidar binds and inhibits Pgp. To assess the toxicity, pharmacokinetics (PK), and pharmacodynamics of tariquidar, we conducted a phase I trial of tariquidar in combination with doxorubicin, docetaxel, or vinorelbine in children and adolescents with recurrent or refractory solid tumors. METHODS Patients less than 19 years of age with refractory or recurrent solid tumors were eligible. Tariquidar (1, 1.5, or 2 mg/kg) was administered alone and in combination with doxorubicin, docetaxel, or vinorelbine. PK of tariquidar and cytotoxic drugs was performed. Pgp function was assessed by a rhodamine efflux assay and (99m)Tc-sestamibi scintigraphy. Tumor Pgp expression was assessed by immunohistochemistry. Response was assessed using Response Evaluation Criteria in Solid Tumors. RESULTS Twenty-nine subjects were enrolled. No tariquidar-related dose-limiting toxicity (DLT) was observed. DLT related to cytotoxic drugs occurred in 12 % of subjects receiving tariquidar 2 mg/kg. When administered in combination with tariquidar, the clearance of docetaxel and vinorelbine was reduced compared to prior studies. Inhibition of rhodamine efflux was dose dependent. After tariquidar administration, (99m)Tc-sestamibi accumulation in tumor increased by 22 %. Objective responses (1 complete, 2 partial) were observed. There was no association between tumor Pgp expression and response. CONCLUSION A tolerable and biologically active dose of tariquidar was established in children and adolescents. This trial demonstrates that modulators of resistance can be evaluated in combination with chemotherapy, and pharmacokinetic and pharmacodynamic endpoints can be useful in determination of recommended dose in children and adolescents.
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15
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Follit CA, Brewer FK, Wise JG, Vogel PD. In silico identified targeted inhibitors of P-glycoprotein overcome multidrug resistance in human cancer cells in culture. Pharmacol Res Perspect 2015; 3:e00170. [PMID: 26516582 PMCID: PMC4618641 DOI: 10.1002/prp2.170] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Revised: 05/21/2015] [Accepted: 06/23/2015] [Indexed: 11/24/2022] Open
Abstract
Failure of cancer chemotherapies is often linked to the over expression of ABC efflux transporters like the multidrug resistance P-glycoprotein (P-gp). P-gp expression in cells leads to the elimination of a variety of chemically unrelated, mostly cytotoxic compounds. Administration of chemotherapeutics during therapy frequently selects for cells that over express P-gp and are therefore capable of robustly exporting diverse compounds, including chemotherapeutics, from the cells. P-gp thus confers multidrug resistance to a majority of drugs currently available for the treatment of cancers and diseases like HIV/AIDS. The search for P-gp inhibitors for use as co-therapeutics to combat multidrug resistances has had little success to date. In a previous study (Brewer et al., Mol Pharmacol 86: 716–726, 2014), we described how ultrahigh throughput computational searches led to the identification of four drug-like molecules that specifically interfere with the energy harvesting steps of substrate transport and inhibit P-gp catalyzed ATP hydrolysis in vitro. In the present study, we demonstrate that three of these compounds reversed P-gp-mediated multidrug resistance of cultured prostate cancer cells to restore sensitivity comparable to naïve prostate cancer cells to the chemotherapeutic drug, paclitaxel. Potentiation concentrations of the inhibitors were <3 μmol/L. The inhibitors did not exhibit significant toxicity to noncancerous cells at concentrations where they reversed multidrug resistance in cancerous cells. Our results indicate that these compounds with novel mechanisms of P-gp inhibition are excellent leads for the development of co-therapeutics for the treatment of multidrug resistances.
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Affiliation(s)
- Courtney A Follit
- Department of Biological Sciences, The Center for Drug Discovery, Design and Delivery, Southern Methodist University Dallas, Texas, 75275-0376
| | - Frances K Brewer
- Department of Biological Sciences, The Center for Drug Discovery, Design and Delivery, Southern Methodist University Dallas, Texas, 75275-0376
| | - John G Wise
- Department of Biological Sciences, The Center for Drug Discovery, Design and Delivery, Southern Methodist University Dallas, Texas, 75275-0376
| | - Pia D Vogel
- Department of Biological Sciences, The Center for Drug Discovery, Design and Delivery, Southern Methodist University Dallas, Texas, 75275-0376
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16
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Chufan EE, Sim HM, Ambudkar SV. Molecular basis of the polyspecificity of P-glycoprotein (ABCB1): recent biochemical and structural studies. Adv Cancer Res 2015; 125:71-96. [PMID: 25640267 DOI: 10.1016/bs.acr.2014.10.003] [Citation(s) in RCA: 103] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
ABCB1 (P-glycoprotein/P-gp) is an ATP-binding cassette transporter well known for its association with multidrug resistance in cancer cells. Powered by the hydrolysis of ATP, it effluxes structurally diverse compounds. In this chapter, we discuss current views on the molecular basis of the substrate polyspecificity of P-gp. One of the features that accounts for this property is the structural flexibility observed in P-gp. Several X-ray crystal structures of mouse P-gp have been published recently in the absence of nucleotide, with and without bound inhibitors. All the structures are in an inward-facing conformation exhibiting different degrees of domain separation, thus revealing a highly flexible protein. Biochemical and biophysical studies also demonstrate this flexibility in mouse as well as human P-gp. Site-directed mutagenesis has revealed the existence of multiple transport-active binding sites in P-gp for a single substrate. Thus, drugs can bind at either primary or secondary sites. Biochemical, molecular modeling, and structure-activity relationship studies suggest a large, common drug-binding pocket with overlapping sites for different substrates. We propose that in addition to the structural flexibility, the molecular or chemical flexibility also contributes to the binding of substrates to multiple sites forming the basis of polyspecificity.
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Affiliation(s)
- Eduardo E Chufan
- Center for Cancer Research, Laboratory of Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Hong-May Sim
- Center for Cancer Research, Laboratory of Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Suresh V Ambudkar
- Center for Cancer Research, Laboratory of Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA.
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17
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Sprachman MM, Laughney AM, Kohler RH, Weissleder R. In vivo imaging of multidrug resistance using a third generation MDR1 inhibitor. Bioconjug Chem 2014; 25:1137-42. [PMID: 24806886 PMCID: PMC4098115 DOI: 10.1021/bc500154c] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Cellular up-regulation of multidrug resistance protein 1 (MDR1) is a common cause for resistance to chemotherapy; development of third generation MDR1 inhibitors-several of which contain a common 6,7-dimethoxy-2-phenethyl-1,2,3,4-tetrahydroisoquinoline substructure-is underway. Efficacy of these agents has been difficult to ascertain, partly due to a lack of pharmacokinetic reporters for quantifying inhibitor localization and transport dynamics. Some of the recent third generation inhibitors have a pendant heterocycle, for example, a chromone moiety, which we hypothesized could be converted to a fluorophore. Following synthesis and teasing of a small set of analogues, we identified one lead compound that can be used as a cellular imaging agent that exhibits structural similarity and behavior akin to the latest generation of MDR1 inhibitors.
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Affiliation(s)
- Melissa M Sprachman
- Center for Systems Biology, Massachusetts General Hospital , 185 Cambridge Street, CPZN 5206, Boston, Massachusetts 02114, United States
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18
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Martinez L, Arnaud O, Henin E, Tao H, Chaptal V, Doshi R, Andrieu T, Dussurgey S, Tod M, Di Pietro A, Zhang Q, Chang G, Falson P. Understanding polyspecificity within the substrate-binding cavity of the human multidrug resistance P-glycoprotein. FEBS J 2014; 281:673-82. [PMID: 24219411 DOI: 10.1111/febs.12613] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Revised: 11/06/2013] [Accepted: 11/07/2013] [Indexed: 11/29/2022]
Abstract
Human P-glycoprotein (P-gp) controls drugs bioavailability by pumping structurally unrelated drugs out of cells. The X-ray structure of the mouse P-gp ortholog has been solved, with two SSS enantiomers or one RRR enantiomer of the selenohexapeptide inhibitor QZ59, found within the putative drug-binding pocket (Aller SG, Yu J, Ward A, Weng Y, Chittaboina S, Zhuo R, Harrell PM, Trinh YT, Zhang Q, Urbatsch IL et al. (2009). Science 323, 1718-1722). This offered the first opportunity to localize the well-known H and R drug-binding sites with respect to the QZ59 inhibition mechanisms of Hoechst 33342 and daunorubicin transports, characterized here in cellulo. We found that QZ59-SSS competes efficiently with both substrates, with K(I,app) values of 0.15 and 0.3 μM, which are 13 and 2 times lower, respectively, than the corresponding K(m,app) values. In contrast, QZ59-RRR non-competitively inhibited daunorubicin transport with moderate efficacy (K(I,app) = 1.9 μM); it also displayed a mixed-type inhibition of the Hoechst 33342 transport, resulting from a main non-competitive tendency (K(i2,app) = 1.6 μM) and a limited competitive tendency (K(i1,app) = 5 μM). These results suggest a positional overlap of QZ59 and drugs binding sites: full for the SSS enantiomer and partial for the RRR enantiomer. Crystal structure analysis suggests that the H site overlaps both QZ59-SSS locations while the R site overlaps the most embedded location.
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Affiliation(s)
- Lorena Martinez
- Drug Resistance Mechanism and Modulation group, Ligue 2013 certified, Molecular and Structural Basis of Infectious Systems, Mixed Research Unit between the National Centre for Scientific Research and Lyon I University n°5086, Institute of Biology and Chemistry of Proteins, France
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Geng M, Wang L, Chen X, Cao R, Li P. The association between chemosensitivity and Pgp, GST-π and Topo II expression in gastric cancer. Diagn Pathol 2013; 8:198. [PMID: 24326092 PMCID: PMC3901556 DOI: 10.1186/1746-1596-8-198] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Accepted: 12/06/2013] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND To investigate the relationship between P-glycoprotein (Pgp), glutathione S-transferase π (GST-π) and topoisomerase II (Topo II) expression and human gastric cancer chemoresistance in vitro. METHODS Primary single-cell suspensions were prepared from fresh specimens of primary gastric cancer and exposed to hydroxycamptothecin (HCPT), cisplatin (CDDP), 5-fluorouracil (5-FU), adriamycin (ADM) and mitomycin (MMC) for 48 h. Cell metabolic activity and rate of inhibition were evaluated using tetrazolium (MTT) assay. Pgp, GST-π and Topo II expression was determined in gastric carcinoma tissue samples using immunohistochemistry. RESULTS Chemosensitivity of the gastric cancer cells varied; the rates of inhibition of cells exposed to HCPT, CDDP and 5-FU were significantly higher than that of cells exposed to ADM and MMC (p < 0.05). Gastric cancer cells with Pgp expression were resistant to ADM and HCPT (p = 0.008 and p = 0.011, respectively). Cells resistant to 5-FU, CDDP and MMC had significantly higher GST-π expression (p < 0.05). Topo II expression was significantly lower in cells resistant to HCPT, ADM and MMC (p < 0.05). Pgp and GST-π expression may contribute to primary resistance of gastric cancer cells to some chemotherapeutic drugs, while Topo II expression may indicate HCPT, ADM and MMC sensitivity. CONCLUSIONS Pgp, GST-π and Topo II detection and the MTT assay could be used as predictors in chemotherapeutic drug administration and for identifying drug resistance in gastric carcinoma. VIRTUAL SLIDES The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/3448329111142964.
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Affiliation(s)
| | | | | | | | - Peifeng Li
- Department of Pathology, General Hospital of Jinan Military Command, Jinan, China.
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