1
|
Mealey KL, Owens JG, Freeman E. Canine and feline P-glycoprotein deficiency: What we know and where we need to go. J Vet Pharmacol Ther 2023; 46:1-16. [PMID: 36326478 PMCID: PMC10092536 DOI: 10.1111/jvp.13102] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 09/09/2022] [Accepted: 10/09/2022] [Indexed: 11/06/2022]
Abstract
In 2001 the molecular genetic basis of so-called "ivermectin sensitivity" in herding breed dogs was determined to be a P-glycoprotein deficiency caused by a genetic variant of the MDR1 (ABCB1) gene often called "the MDR1 mutation." We have learned a great deal about P-glycoprotein's role in drug disposition since that discovery, namely that P-glycoprotein transports many more drugs than just macrocyclic lactones that P-glycoprotein mediated drug transport is present in more places than just the blood brain barrier, that some cats have a genetic variant of MDR1 that results in P-glycoprotein deficiency, that P-glycoprotein dysfunction can occur as a result of drug-drug interactions in any dog or cat, and that the concept of P-glycoprotein "inhibitors" versus P-glycoprotein substrates is somewhat arbitrary and artificial. This paper will review these discoveries and discuss how they impact drug selection and dosing in dogs and cats with genetically mediated P-glycoprotein deficiency or P-glycoprotein dysfunction resulting from drug-drug interactions.
Collapse
Affiliation(s)
- Katrina L Mealey
- Program in Individualized Medicine, Department of Veterinary Clinical Sciences, Washington State University, Pullman, Washington, USA
| | | | | |
Collapse
|
2
|
GSK-3β, FYN, and DYRK1A: Master Regulators in Neurodegenerative Pathways. Int J Mol Sci 2021; 22:ijms22169098. [PMID: 34445804 PMCID: PMC8396491 DOI: 10.3390/ijms22169098] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 08/16/2021] [Accepted: 08/19/2021] [Indexed: 12/14/2022] Open
Abstract
Protein kinases (PKs) have been recognized as central nervous system (CNS)-disease-relevant targets due to their master regulatory role in different signal transduction cascades in the neuroscience space. Among them, GSK-3β, FYN, and DYRK1A play a crucial role in the neurodegeneration context, and the deregulation of all three PKs has been linked to different CNS disorders with unmet medical needs, including Alzheimer’s disease (AD), Parkinson’s disease (PD), frontotemporal lobar degeneration (FTLD), and several neuromuscular disorders. The multifactorial nature of these diseases, along with the failure of many advanced CNS clinical trials, and the lengthy approval process of a novel CNS drug have strongly limited the CNS drug discovery. However, in the near-decade from 2010 to 2020, several computer-assisted drug design strategies have been combined with synthetic efforts to develop potent and selective GSK-3β, FYN, and DYRK1A inhibitors as disease-modifying agents. In this review, we described both structural and functional aspects of GSK-3β, FYN, and DYRK1A and their involvement and crosstalk in different CNS pathological signaling pathways. Moreover, we outlined attractive medicinal chemistry approaches including multi-target drug design strategies applied to overcome some limitations of known PKs inhibitors and discover improved modulators with suitable blood–brain barrier (BBB) permeability and drug-like properties.
Collapse
|
3
|
Palko-Łabuz A, Błaszczyk M, Środa-Pomianek K, Wesołowska O. Isobavachalcone as an Active Membrane Perturbing Agent and Inhibitor of ABCB1 Multidrug Transporter. Molecules 2021; 26:molecules26154637. [PMID: 34361789 PMCID: PMC8347294 DOI: 10.3390/molecules26154637] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 07/26/2021] [Accepted: 07/29/2021] [Indexed: 11/16/2022] Open
Abstract
Isobavachalcone (IBC) is an active substance from the medicinal plant Psoralea corylifolia. This prenylated chalcone was reported to possess antioxidative, anti-inflammatory, antibacterial, and anticancer activities. Multidrug resistance (MDR) associated with the over-expression of the transporters of vast substrate specificity such as ABCB1 (P-glycoprotein) belongs to the main causes of cancer chemotherapy failure. The cytotoxic, MDR reversing, and ABCB1-inhibiting potency of isobavachalcone was studied in two cellular models: human colorectal adenocarcinoma HT29 cell line and its resistant counterpart HT29/Dx in which doxorubicin resistance was induced by prolonged drug treatment, and the variant of MDCK cells transfected with the human gene encoding ABCB1. Because MDR modulators are frequently membrane-active substances, the interaction of isobavachalcone with model phosphatidylcholine bilayers was studied by means of differential scanning calorimetry. Molecular modeling was employed to characterize the process of membrane permeation by isobavachalcone. IBC interacted with ABCB1 transporter, being a substrate and/or competitive inhibitor of ABCB1. Moreover, IBC intercalated into model membranes, significantly affecting the parameters of their main phospholipid phase transition. It was concluded that isobavachalcone interfered both with the lipid phase of cellular membrane and with ABCB1 transporter, and for this reason, its activity in MDR cancer cells was presumptively beneficial.
Collapse
MESH Headings
- ATP Binding Cassette Transporter, Subfamily B/antagonists & inhibitors
- ATP Binding Cassette Transporter, Subfamily B/genetics
- ATP Binding Cassette Transporter, Subfamily B/metabolism
- Animals
- Antibiotics, Antineoplastic/pharmacology
- Antineoplastic Agents, Phytogenic/chemistry
- Antineoplastic Agents, Phytogenic/isolation & purification
- Antineoplastic Agents, Phytogenic/pharmacology
- Binding, Competitive
- Cell Line, Tumor
- Chalcones/chemistry
- Chalcones/isolation & purification
- Chalcones/pharmacology
- Dogs
- Doxorubicin/pharmacology
- Drug Combinations
- Drug Resistance, Neoplasm/drug effects
- Drug Resistance, Neoplasm/genetics
- Gene Expression
- HT29 Cells
- Humans
- Inhibitory Concentration 50
- Lipid Bilayers/chemistry
- Lipid Bilayers/metabolism
- Madin Darby Canine Kidney Cells
- Membranes, Artificial
- Models, Molecular
- Phosphatidylcholines/chemistry
- Phosphatidylcholines/metabolism
- Plant Extracts/chemistry
- Plants, Medicinal
- Protein Binding
- Psoralea/chemistry
- Transgenes
- Verapamil/pharmacology
Collapse
|
4
|
Hansen TWR, Wong RJ, Stevenson DK. Molecular Physiology and Pathophysiology of Bilirubin Handling by the Blood, Liver, Intestine, and Brain in the Newborn. Physiol Rev 2020; 100:1291-1346. [PMID: 32401177 DOI: 10.1152/physrev.00004.2019] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Bilirubin is the end product of heme catabolism formed during a process that involves oxidation-reduction reactions and conserves iron body stores. Unconjugated hyperbilirubinemia is common in newborn infants, but rare later in life. The basic physiology of bilirubin metabolism, such as production, transport, and excretion, has been well described. However, in the neonate, numerous variables related to nutrition, ethnicity, and genetic variants at several metabolic steps may be superimposed on the normal physiological hyperbilirubinemia that occurs in the first week of life and results in bilirubin levels that may be toxic to the brain. Bilirubin exists in several isomeric forms that differ in their polarities and is considered a physiologically important antioxidant. Here we review the chemistry of the bilirubin molecule and its metabolism in the body with a particular focus on the processes that impact the newborn infant, and how differences relative to older children and adults contribute to the risk of developing both acute and long-term neurological sequelae in the newborn infant. The final section deals with the interplay between the brain and bilirubin and its entry, clearance, and accumulation. We conclude with a discussion of the current state of knowledge regarding the mechanism(s) of bilirubin neurotoxicity.
Collapse
Affiliation(s)
- Thor W R Hansen
- Division of Paediatric and Adolescent Medicine, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway; and Department of Pediatrics, Stanford University School of Medicine, Stanford, California
| | - Ronald J Wong
- Division of Paediatric and Adolescent Medicine, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway; and Department of Pediatrics, Stanford University School of Medicine, Stanford, California
| | - David K Stevenson
- Division of Paediatric and Adolescent Medicine, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway; and Department of Pediatrics, Stanford University School of Medicine, Stanford, California
| |
Collapse
|
5
|
Abstract
OBJECTIVE Ospemifene, an estrogen receptor agonist/antagonist approved for the treatment of dyspareunia and vaginal dryness in postmenopausal women, has potential new indications as an immune modulator. The overall objective of the present series of preclinical studies was to evaluate the immunomodulatory activity of ospemifene in combination with a peptide cancer vaccine. METHODS Immune regulating effects, mechanism of action and structure activity relationships of ospemifene and related compounds were evaluated by examining expression of T-cell activating cytokines in vitro, and antigen-specific immune response and cytotoxic T-lymphocyte activity in vivo. The effects of ospemifene (OSP) on the immune response to a peptide cancer vaccine (PV) were evaluated after chronic [control (n = 22); OSP 50 mg/kg (n = 16); PV (n = 6); OSP+PV (n = 11)], intermittent [control (n = 10); OSP 10 and 50 mg/kg (n = 11); PV (n = 11); combination treatment (n = 11 each dose)] and pretreatment [control; OSP 100 mg/kg; PV 100 μg; combination treatment (n = 8 all groups)] ospemifene oral dosing schedules in a total of 317 mixed-sex tumor-bearing and nontumor-bearing mice. RESULTS The results showed that ospemifene induced expression of the key TH1 cytokines interferon gamma and interleukin-2 in vitro, which may be mediated by stimulating T-cells through phosphoinositide 3-kinase and calmodulin signaling pathways. In combination with an antigen-specific peptide cancer vaccine, ospemifene increased antigen-specific immune response and increased cytotoxic T-lymphocyte activity in tumor-bearing and nontumor-bearing mice. The pretreatment, intermittent, and chronic dosing schedules of ospemifene activate naive T-cells, modulate antigen-induced tolerance and reduce tumor-associated, pro-inflammatory cytokines, respectively. CONCLUSIONS Taken together, ospemifene's dose response and schedule-dependent immune modulating activity offers a method of tailoring and augmenting the efficacy of previously failed antigen-specific cancer vaccines for a wide range of malignancies.
Collapse
|
6
|
Mealey KL, Fidel J. P-glycoprotein mediated drug interactions in animals and humans with cancer. J Vet Intern Med 2015; 29:1-6. [PMID: 25619511 PMCID: PMC4858061 DOI: 10.1111/jvim.12525] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Revised: 10/08/2014] [Accepted: 11/17/2014] [Indexed: 02/05/2023] Open
Abstract
Drug–drug interactions can cause unanticipated patient morbidity and mortality. The consequences of drug–drug interactions can be especially severe when anticancer drugs are involved because of their narrow therapeutic index. Veterinary clinicians have traditionally been taught that drug–drug interactions result from alterations in drug metabolism, renal excretion or protein binding. More recently, drug–drug interactions resulting from inhibition of P‐glycoprotein‐mediated drug transport have been identified in both human and veterinary patients. Many drugs commonly used in veterinary patients are capable of inhibiting P‐glycoprotein function and thereby causing an interaction that results in severe chemotherapeutic drug toxicity. The intent of this review is to describe the mechanism and clinical implications of drug–drug interactions involving P‐glycoprotein and anticancer drugs. Equipped with this information, veterinarians can prevent serious drug–drug interactions by selecting alternate drugs or adjusting the dose of interacting drugs.
Collapse
Affiliation(s)
- K L Mealey
- Program in Individualized Medicine (PrIMe), Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Washington State University, Pullman, WA
| | | |
Collapse
|
7
|
Kurth D, Brack W, Luckenbach T. Is chemosensitisation by environmental pollutants ecotoxicologically relevant? AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2015; 167:134-42. [PMID: 26281775 DOI: 10.1016/j.aquatox.2015.07.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Revised: 07/28/2015] [Accepted: 07/28/2015] [Indexed: 05/11/2023]
Abstract
The active cellular efflux of toxicants is an efficient biological defense mode present in all organisms. By blocking this so-called multixenobiotic resistance transport-a process also referred to as chemosensitisation-, cellular bioaccumulation and the sensitivity of organisms towards environmental pollutants can increase. So far, a wide range of compounds, including pesticides, pharmaceuticals, fragrances, and surfactants, have been identified as chemosensitisers. Although, significant on a cellular level, the environmental impact of chemosensitisation on the organism level is not yet understood. Critically evaluating existing data, this paper identifies research needs to support our tentative conclusion that chemosensitisation may well enhance the risks of chemical exposure to aquatic organisms. Our conclusion is based on studies investigating the impact of individual chemicals and complex environmental mixtures on aquatic wildlife and a chemosensitiser mixture toxicity model which, however, is subject to great uncertainty due to substantial knowledge gaps. Those uncertainties include the inconsistent reporting of effect data, the lack of representative environmental contaminants tested for chemosensitisation, and the publishing of highly unreliable nominal exposure concentrations. In order to confirm the tentative conclusion of this paper, we require the significant and systematic investigation of a broader set of chemicals and environmental samples with a harmonised set of bioassays and rigorously controlled freely dissolved effect concentrations.
Collapse
Affiliation(s)
- Denise Kurth
- UFZ-Helmholtz Centre for Environmental Research, Department of Effect-Directed Analysis, Permoserstr. 15, 04318 Leipzig, Germany; RWTH Aachen University, Department of Ecosystem Analyses, Institute for Environmental Research, Worringerweg 1, 52074, Aachen, Germany
| | - Werner Brack
- UFZ-Helmholtz Centre for Environmental Research, Department of Effect-Directed Analysis, Permoserstr. 15, 04318 Leipzig, Germany; RWTH Aachen University, Department of Ecosystem Analyses, Institute for Environmental Research, Worringerweg 1, 52074, Aachen, Germany.
| | - Till Luckenbach
- UFZ-Helmholtz Centre for Environmental Research, Department of Bioanalytical Ecotoxicology, Permoserstr. 15, 04318 Leipzig, Germany
| |
Collapse
|
8
|
Saab AM, Guerrini A, Zeino M, Wiench B, Rossi D, Gambari R, Sacchetti G, Greten HJ, Efferth T. Laurus nobilisL. Seed Extract Reveals Collateral Sensitivity in Multidrug-Resistant P-Glycoprotein-Expressing Tumor Cells. Nutr Cancer 2015; 67:664-75. [DOI: 10.1080/01635581.2015.1019632] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
|
9
|
Gamal M, Moawad J, Rashed L, El-Eraky W, Saleh D, Lehmann C, Sharawy N. Evaluation of the effects of Eserine and JWH-133 on brain dysfunction associated with experimental endotoxemia. J Neuroimmunol 2015; 281:9-16. [DOI: 10.1016/j.jneuroim.2015.02.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2014] [Revised: 11/02/2014] [Accepted: 02/28/2015] [Indexed: 11/28/2022]
|
10
|
Luckenbach T, Fischer S, Sturm A. Current advances on ABC drug transporters in fish. Comp Biochem Physiol C Toxicol Pharmacol 2014; 165:28-52. [PMID: 24858718 DOI: 10.1016/j.cbpc.2014.05.002] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Revised: 05/13/2014] [Accepted: 05/14/2014] [Indexed: 01/14/2023]
Abstract
Most members of the large ATP-binding cassette (ABC) gene family are transporters involved in substrate translocation across biological membranes. In eukaryotes, ABC proteins functioning as drug transporters are located in the plasma membrane and mediate the cellular efflux of a wide range of organic chemicals, with some transporters also transporting certain metals. As the enhanced expression of ABC drug transporters can confer multidrug resistance (MDR) to cancers and multixenobiotic resistance (MXR) to organisms from polluted habitats, these ABC family members are also referred to as MDR or MXR proteins. In mammals, ABC drug transporters show predominant expression in tissues involved in excretion or constituting internal or external body boundaries, where they facilitate the excretion of chemicals and their metabolites, and limit chemical uptake and penetration into "sanctuary" sites of the body. Available knowledge about ABC proteins is still limited in teleost fish, a large vertebrate group of high ecological and economic importance. Using transport activity measurements and immunochemical approaches, early studies demonstrated similarities in the tissue distribution of ABC drug transporters between teleosts and mammals, suggesting conserved roles of the transporters in the biochemical defence against toxicants. Recently, the availability of teleost genome assemblies has stimulated studies of the ABC family in this taxon. This review summarises the current knowledge regarding the genetics, functional properties, physiological function, and ecotoxicological relevance of teleostean ABC transporters. The available literature is reviewed with emphasis on recent studies addressing the tissue distribution, substrate spectrum, regulation, physiological function and phylogenetic origin of teleostean ABC transporters.
Collapse
Affiliation(s)
- Till Luckenbach
- Department of Bioanalytical Ecotoxicology, UFZ-Helmholtz Centre for Environmental Research, 04318 Leipzig, Germany
| | - Stephan Fischer
- Department of Environmental Toxicology, Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland; Department of Environmental Systems Sciences, ETH Zürich, Institute of Biogeochemistry and Pollutant Dynamics, 8092 Zürich, Switzerland
| | - Armin Sturm
- Institute of Aquaculture, School of Natural Sciences, University of Stirling, Stirling FK9 4LA, Scotland, UK.
| |
Collapse
|
11
|
Radadiya A, Khedkar V, Bavishi A, Vala H, Thakrar S, Bhavsar D, Shah A, Coutinho E. Synthesis and 3D-QSAR study of 1,4-dihydropyridine derivatives as MDR cancer reverters. Eur J Med Chem 2014; 74:375-87. [DOI: 10.1016/j.ejmech.2014.01.011] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Revised: 01/03/2014] [Accepted: 01/06/2014] [Indexed: 11/26/2022]
|
12
|
Kim SS, Seong S, Kim SY. Synergistic effect of ginsenoside Rg3 with verapamil on the modulation of multidrug resistance in human acute myeloid leukemia cells. Oncol Lett 2014; 7:1265-1269. [PMID: 24944704 PMCID: PMC3961386 DOI: 10.3892/ol.2014.1826] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Accepted: 12/02/2013] [Indexed: 12/04/2022] Open
Abstract
The pharmacological modulatory effects of 20(S)-ginsenoside Rg3 (20S-Rg3) on multidrug resistant cancer cells are reported in the present study. The effects of 20(S)-Rg3 on the modulation of doxorubicin (DOX) and vincristine (VCR) resistance were examined in the HL60 multidrug resistant subline of human acute myeloid leukemia cells. Results demonstrated that 20S-Rg3 is as effective as verapamil (Vp) for modulating the high degree primary DOX resistance and low degree VCR cross-resistance expressed by the H160 cell line. Furthermore, the present study demonstrates for the first time, using isobologram analysis, that the combination of 20S-Rg3 and Vp enhances the reversal of DOX and VCR resistance in a supra-additive or at least an additive manner. These results indicate that 20S-Rg3 may be used as a Vp synergizer or as a promising alternative to Vp in the chemosensitization of multidrug resistant acute myeloid leukemia, with far fewer side effects.
Collapse
Affiliation(s)
- Sung Su Kim
- Department of Oriental Medicine, Kyung Hee University College of Oriental Medicine, Seoul 130-701, Republic of Korea
| | - Sin Seong
- Department of Oriental Medicine, Kyung Hee University College of Oriental Medicine, Seoul 130-701, Republic of Korea
| | - Sung Young Kim
- Department of Biochemistry, School of Medicine, Konkuk University, Seoul 143-701, Republic of Korea
| |
Collapse
|
13
|
Dapat E, Jacinto S, Efferth T. A phenolic ester from Aglaia loheri leaves reveals cytotoxicity towards sensitive and multidrug-resistant cancer cells. Altern Ther Health Med 2013; 13:286. [PMID: 24160768 PMCID: PMC3816152 DOI: 10.1186/1472-6882-13-286] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2012] [Accepted: 10/25/2013] [Indexed: 12/23/2022]
Abstract
BACKGROUND Bioactivity-guided fractionation of extracts of Aglaia loheri Blanco (Meliaceae) yielded a cytotoxic isolate, termed Maldi 531.2[M + H]+. This phenolic ester was further investigated for its in vitro cytotoxicity toward human CCRF-CEM leukemia cells and their multi-drug resistant (MDR) subline, CEM/ADR5000. The intrinsic mitochondrial membrane potential (ΔΨm) and induction of apoptosis by this isolate were evaluated. METHODS Chromatography techniques, mass spectrometry and proton NMR were employed to isolate Maldi 531.2[M + H]+. XTT cell proliferation and viability assay was used for cytotoxic test, and JC-1[5',5',6,6',-tetrachloro-1,1',3,3'-tetraethylbenzimidazoyl carbocyanine iodide was used to assess ΔΨm and initiation of apoptosis; Annexin V/FITC-PI staining was employed to analyse apoptosis. RESULTS Maldi 531.2[M + H]+ was cytotoxic towards both CCRF-CEM and CEM/ADR5000 cells with IC50 values of 0.02 and 0.03 μM, respectively. The mitochondrial membrane potential (ΔΨm) of MDR cells was significantly reduced in a dose-dependent manner leading to apoptosis as detected by flow cytometric Annexin V-FITC/ PI staining. CONCLUSION Maldi 531.2[M + H]+ may be a potential anti-cancer drug candidate whose mode of action include reduction of the mitochondrial membrane potential and induction of apoptosis.
Collapse
|
14
|
Romero-Canelón I, Sadler PJ. Next-Generation Metal Anticancer Complexes: Multitargeting via Redox Modulation. Inorg Chem 2013; 52:12276-91. [DOI: 10.1021/ic400835n] [Citation(s) in RCA: 307] [Impact Index Per Article: 27.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
| | - Peter J. Sadler
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong,
People’s Republic of China
| |
Collapse
|
15
|
Emerging nanodelivery strategies of RNAi molecules for colon cancer therapy: preclinical developments. Ther Deliv 2012; 3:1117-30. [DOI: 10.4155/tde.12.89] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Although local colonic delivery is achievable through several strategies, colon cancer is still considered one of the leading causes of death worldwide. Failure of chemotherapeutics to exhibit efficient anticancer activity might be attributed to the development of multidrug resistance (MDR) mechanisms including the overexpression of certain oncogenes such as MDR1/P-gp. One of the major reasons for the shortcoming of P-gp inhibitors in clinic is the nonspecific distribution of them to nontarget organs, which leads to reduced elimination and increased toxicity of its substrates including anticancer agents. Numerous studies have demonstrated the effectiveness of gene-silencing approaches in reversing the P-gp-mediated MDR. However, none have reached clinical trials yet. Several drug-delivery systems have been investigated primarily to address P-gp and the observed improved anticancer efficacy suggests that nanomedicine provides new opportunities to overcome MDR in cancer. In this review, novel therapeutic strategies for colon cancer therapy will be discussed in the context of P-gp inhibition by low-molecular-weight agents and RNAi molecules.
Collapse
|
16
|
Zhang C, Kwan P, Zuo Z, Baum L. The transport of antiepileptic drugs by P-glycoprotein. Adv Drug Deliv Rev 2012; 64:930-42. [PMID: 22197850 DOI: 10.1016/j.addr.2011.12.003] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2011] [Revised: 12/05/2011] [Accepted: 12/07/2011] [Indexed: 01/16/2023]
Abstract
Epilepsy is the most common serious chronic neurological disorder. Current data show that one-third of patients do not respond to anti-epileptic drugs (AEDs). Most non-responsive epilepsy patients are resistant to several, often all, AEDs, even though the drugs differ from each other in pharmacokinetics, mechanisms of action, and interaction potential. The mechanisms underlying drug resistance of epilepsy patients are still not clear. In recent years, one of the potential mechanisms interesting researchers is over-expression of P-glycoprotein (P-gp, also known as ABCB1 or MDR1) in endothelial cells of the blood-brain barrier (BBB) in epilepsy patients. P-gp plays a central role in drug absorption and distribution in many organisms. The expression of P-gp is greater in drug-resistant than in drug-responsive patients. Some studies also indicate that several AEDs are substrates or inhibitors of P-gp, implying that P-gp may play an important role in drug resistance in refractory epilepsy. In this article, we review the clinical and laboratory evidence that P-gp expression is increased in epileptic brain tissues and that AEDs are substrates of P-gp in vitro and in vivo. We discuss criteria for identifying the substrate status of AEDs and use structure-activity relationship (SAR) models to predict which AEDs act as P-gp substrates.
Collapse
|
17
|
Eichhorn T, Efferth T. P-glycoprotein and its inhibition in tumors by phytochemicals derived from Chinese herbs. JOURNAL OF ETHNOPHARMACOLOGY 2012; 141:557-570. [PMID: 21963565 DOI: 10.1016/j.jep.2011.08.053] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Revised: 08/19/2011] [Accepted: 08/25/2011] [Indexed: 05/31/2023]
Abstract
P-glycoprotein belongs to the family of ATP-binding cassette (ABC) transporters. It functions in cellular detoxification, pumping a wide range of xenobiotic compounds, including anticancer drugs out of the cell. In cancerous cells, P-glycoprotein confers resistance to a broad spectrum of anticancer agents, a phenomenon termed multidrug resistance. An attractive strategy for overcoming multidrug resistance is to block the transport function of P-glycoprotein and thus increase intracellular concentrations of anticancer drugs to lethal levels. Efforts to identify P-glycoprotein inhibitors have led to numerous candidates, none of which have passed clinical trials with cancer patients due to their high toxicity. The search for naturally inhibitory products from traditional Chinese medicine may be more promising because natural products are frequently less toxic than chemically synthesized substances. In this review, we give an overview of molecular and clinical aspects of P-glycoprotein and multidrug resistance in the context of cancer as well as Chinese herbs and phytochemicals showing inhibitory activity towards P-glycoprotein.
Collapse
MESH Headings
- ATP Binding Cassette Transporter, Subfamily B, Member 1/antagonists & inhibitors
- ATP Binding Cassette Transporter, Subfamily B, Member 1/metabolism
- Animals
- Antineoplastic Agents, Phytogenic/adverse effects
- Antineoplastic Agents, Phytogenic/therapeutic use
- Drug Resistance, Neoplasm
- Drugs, Chinese Herbal/adverse effects
- Drugs, Chinese Herbal/therapeutic use
- Humans
- Neoplasms/drug therapy
- Neoplasms/metabolism
- Plants, Medicinal
Collapse
Affiliation(s)
- Tolga Eichhorn
- Department of Pharmaceutical Biology, Institute of Pharmacy and Biochemistry, Johannes Gutenberg University, Mainz, Germany
| | | |
Collapse
|
18
|
Campbell BC, Chan KL, Kim JH. Chemosensitization as a means to augment commercial antifungal agents. Front Microbiol 2012; 3:79. [PMID: 22393330 PMCID: PMC3289909 DOI: 10.3389/fmicb.2012.00079] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2011] [Accepted: 02/15/2012] [Indexed: 11/13/2022] Open
Abstract
Antimycotic chemosensitization and its mode of action are of growing interest. Currently, use of antifungal agents in agriculture and medicine has a number of obstacles. Foremost of these is development of resistance or cross-resistance to one or more antifungal agents. The generally high expense and negative impact, or side effects, associated with antifungal agents are two further issues of concern. Collectively, these problems are exacerbated by efforts to control resistant strains, which can evolve into a treadmill of higher dosages for longer periods. This cycle in turn, inflates cost of treatment, dramatically. A further problem is stagnation in development of new and effective antifungal agents, especially for treatment of human mycoses. Efforts to overcome some of these issues have involved using combinations of available antimycotics (e.g., combination therapy for invasive mycoses). However, this approach has had inconsistent success and is often associated with a marked increase in negative side effects. Chemosensitization by natural compounds to increase effectiveness of commercial antimycotics is a somewhat new approach to dealing with the aforementioned problems. The potential for safe natural products to improve antifungal activity has been observed for over three decades. Chemosensitizing agents possess antifungal activity, but at insufficient levels to serve as antimycotics, alone. Their main function is to disrupt fungal stress response, destabilize the structural integrity of cellular and vacuolar membranes or stimulate production of reactive oxygen species, augmenting oxidative stress and apoptosis. Use of safe chemosensitizing agents has potential benefit to both agriculture and medicine. When co-applied with a commercial antifungal agent, an additive or synergistic interaction may occur, augmenting antifungal efficacy. This augmentation, in turn, lowers effective dosages, costs, negative side effects and, in some cases, countermands resistance.
Collapse
Affiliation(s)
- Bruce C. Campbell
- Plant Mycotoxin Research Unit, Western Regional Research Center, Agricultural Research Service, United States Department of AgricultureAlbany, CA, USA
| | - Kathleen L. Chan
- Plant Mycotoxin Research Unit, Western Regional Research Center, Agricultural Research Service, United States Department of AgricultureAlbany, CA, USA
| | - Jong H. Kim
- Plant Mycotoxin Research Unit, Western Regional Research Center, Agricultural Research Service, United States Department of AgricultureAlbany, CA, USA
| |
Collapse
|
19
|
Yang WS, Shimada K, Delva D, Patel M, Ode E, Skouta R, Stockwell BR. Identification of Simple Compounds with Microtubule-Binding Activity That Inhibit Cancer Cell Growth with High Potency. ACS Med Chem Lett 2012; 3:35-38. [PMID: 22247791 PMCID: PMC3256933 DOI: 10.1021/ml200195s] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Accepted: 10/31/2011] [Indexed: 02/07/2023] Open
Abstract
![]()
We analyzed more than 1 million small molecules with
the goal of
finding simple synthetic compounds that potently inhibit cancer cell
growth. We identified three such compounds with unknown mechanisms
of action. Subsequent studies revealed that all three of these small
molecules target microtubules. These three scaffolds can serve as
templates for developing new microtubule-targeted agents, overcoming
the limits of existing microtubule-inhibiting drugs derived from complex
natural products.
Collapse
Affiliation(s)
- Wan Seok Yang
- Department
of Biological Sciences, ‡Department of Chemistry, and §Howard Hughes Medical Institute, Columbia University, Northwest Corner
Building, 12th Floor, 550 West 120th Street, MC 4846, New York, New
York 10027, United States
| | - Kenichi Shimada
- Department
of Biological Sciences, ‡Department of Chemistry, and §Howard Hughes Medical Institute, Columbia University, Northwest Corner
Building, 12th Floor, 550 West 120th Street, MC 4846, New York, New
York 10027, United States
| | - Darnelle Delva
- Department
of Biological Sciences, ‡Department of Chemistry, and §Howard Hughes Medical Institute, Columbia University, Northwest Corner
Building, 12th Floor, 550 West 120th Street, MC 4846, New York, New
York 10027, United States
| | - Milesh Patel
- Department
of Biological Sciences, ‡Department of Chemistry, and §Howard Hughes Medical Institute, Columbia University, Northwest Corner
Building, 12th Floor, 550 West 120th Street, MC 4846, New York, New
York 10027, United States
| | - Egberamwen Ode
- Department
of Biological Sciences, ‡Department of Chemistry, and §Howard Hughes Medical Institute, Columbia University, Northwest Corner
Building, 12th Floor, 550 West 120th Street, MC 4846, New York, New
York 10027, United States
| | - Rachid Skouta
- Department
of Biological Sciences, ‡Department of Chemistry, and §Howard Hughes Medical Institute, Columbia University, Northwest Corner
Building, 12th Floor, 550 West 120th Street, MC 4846, New York, New
York 10027, United States
| | - Brent R. Stockwell
- Department
of Biological Sciences, ‡Department of Chemistry, and §Howard Hughes Medical Institute, Columbia University, Northwest Corner
Building, 12th Floor, 550 West 120th Street, MC 4846, New York, New
York 10027, United States
| |
Collapse
|
20
|
Mine N, Yamamoto S, Saito N, Yamazaki S, Suda C, Ishigaki M, Kufe DW, Von Hoff DD, Kawabe T. CBP501-calmodulin binding contributes to sensitizing tumor cells to cisplatin and bleomycin. Mol Cancer Ther 2011; 10:1929-38. [PMID: 21831962 DOI: 10.1158/1535-7163.mct-10-1139] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
CBP501 is an anticancer drug currently in randomized phase II clinical trials for patients with non-small cell lung cancer and malignant pleural mesothelioma. CBP501 was originally described as a unique G(2) checkpoint-directed agent that binds to 14-3-3, inhibiting the actions of Chk1, Chk2, mitogen-activated protein kinase-activated protein kinase 2, and C-Tak1. However, unlike a G(2) checkpoint inhibitor, CBP501 clearly enhances the accumulation of tumor cells at G(2)-M phase that is induced by cisplatin or bleomycin at low doses and short exposure. By contrast, CBP501 does not similarly affect the accumulation of tumor cells at G(2)-M that is induced by radiation, doxorubicin, or 5-fluorouracil treatment. Our recent findings point to an additional mechanism of action for CBP501. The enhanced accumulation of tumor cells at G(2)-M upon combined treatment with cisplatin and CBP501 results from an increase in intracellular platinum concentrations, which leads to increased binding of platinum to DNA. The observed CBP501-enhanced platinum accumulation is negated in the presence of excess Ca(2+). Some calmodulin inhibitors behave similarly to, although less potently than, CBP501. Furthermore, analysis by surface plasmon resonance reveals a direct, high-affinity molecular interaction between CBP501 and CaM (K(d) = 4.62 × 10(-8) mol/L) that is reversed by Ca(2+), whereas the K(d) for the complex between CBP501 and 14-3-3 is approximately 10-fold weaker and is Ca(2+) independent. We conclude that CaM inhibition contributes to CBP501's activity in sensitizing cancer cells to cisplatin or bleomycin. This article presents an additional mechanism of action which might explain the clinical activity of the CBP501-cisplatin combination.
Collapse
Affiliation(s)
- Naoki Mine
- CanBas Co., Ltd., 2-2-1 Otemachi, Numazu City 410-0801, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Zheng Z, Aojula H, Clarke D. Reduction of doxorubicin resistance in P-glycoprotein overexpressing cells by hybrid cell-penetrating and drug-binding peptide. J Drug Target 2010; 18:477-87. [PMID: 20088680 DOI: 10.3109/10611860903548347] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Drug efflux by the membrane transporter P-glycoprotein (P-gp) plays a key role in multidrug resistance (MDR). In order to bypass P-gp, thus overcoming MDR, a hybrid peptide comprising a cell penetrating peptide (Tat) and a drug binding motif (DBM) has been developed to noncovalently bind and deliver doxorubicin (Dox) into MDR cells. The uptake of Dox into the leukemia cell line K562 and its P-gp overexpressing subline KD30 increased in the presence of DBM-Tat peptide. Confocal microscopy indicated that DBM-Tat associated Dox was directed to a perinuclear area of KD30 cells, while this was not observed in parent K562 cells. When KD30 cells were pretreated with the endosomotropic agent chloroquine (CLQ), peptide associated Dox redistributed into the cytosol, indicating that endocytosis was the predominant uptake route. Altered drug uptake kinetics observed by cellular accumulation assay also supported an endocytic uptake. In the presence of CLQ, DBM-Tat was able to enhance the cytotoxicity of Dox by 68.4% at 5 microM peptide concentration in KD30 cells but there were only minor effects on Dox cytotoxicity in K562 cells even in the presence of CLQ. Thus, combining Dox with DBM-Tat reduces P-gp mediated drug efflux, without a requirement for drug modification or inhibiting P-gp function.
Collapse
Affiliation(s)
- Zhaohua Zheng
- School of Pharmacy and Pharmaceutical Sciences, The University of Manchester, Stopford Building, Oxford Road, Manchester, UK.
| | | | | |
Collapse
|
22
|
Abstract
The blood-brain barrier (BBB) is a dynamic physical and biological barrier between blood circulation and the central nervous system (CNS). This unique feature of the BBB lies in the structure of the neurovascular unit and its cerebral micro-vascular endothelial cells. The BBB restricts the passage of blood-borne drugs, neurotoxic substances and peripheral immune cells from entering the brain, while selectively facilitating the transport of nutrients across the BBB into the brain. Thus, the integrity and proper function of the BBB is crucial to homeostasis and physiological function of the CNS. A number of transport and carrier systems are expressed and polarized on the luminal or abluminal surface of the BBB to realize these discrete functions. Among these systems, ABC transporters play a critical role in keeping drugs and neurotoxic substances from entering the brain and in transporting toxic metabolites out of the brain. A number of studies have demonstrated that ABCB1 and ABCG2 are critical to drug efflux at the BBB and that ABCC1 is essential for the blood-cerebral spinal fluid (CSF) barrier. The presence of these efflux ABC transporters also creates a major obstacle for drug delivery into the brain. We have comprehensively reviewed the literature on ABC transporters and drug efflux at the BBB. Understanding the molecular mechanisms of these transporters is important in the development of new drugs and new strategies for drug delivery into the brain.
Collapse
Affiliation(s)
- Shanshan Shen
- Neurobiology Program, Institute for Biological Sciences, National Research Council of Canada, Ottawa, Canada K1A 0R6
| | | |
Collapse
|
23
|
The antipsychotic drug chlorpromazine enhances the cytotoxic effect of tamoxifen in tamoxifen-sensitive and tamoxifen-resistant human breast cancer cells. Anticancer Drugs 2009; 20:723-35. [PMID: 19584708 DOI: 10.1097/cad.0b013e32832ec041] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Tamoxifen resistance is a major clinical problem in the treatment of estrogen receptor alpha-positive breast tumors. It is, at present, unclear what exactly causes tamoxifen resistance. For decades, chlorpromazine has been used for treating psychotic diseases, such as schizophrenia. However, the compound is now also recognized as a multitargeting drug with diverse potential applications, for example, it has antiproliferative properties and it can reverse resistance toward antibiotics in bacteria. Furthermore, chlorpromazine can reverse multidrug resistance caused by overexpression of P-glycoprotein in cancer cells. In this study, we have investigated the effect of chlorpromazine on tamoxifen response of human breast cancer cells. We found that chlorpromazine worked synergistically together with tamoxifen with respect to reduction of cell growth and metabolic activity, both in the antiestrogen-sensitive breast cancer cell line, MCF-7, and in a tamoxifen-resistant cell line, established from the MCF-7 cells. Tamoxifen-sensitive and tamoxifen-resistant cells were killed equally well by combined treatment with chlorpromazine and tamoxifen. This synergistic effect could be prevented by addition of estrogen, suggesting that chlorpromazine enhances the effect of tamoxifen through an estrogen receptor-mediated mechanism. To investigate this putative mechanism, we applied biophysical techniques to simple model membranes in the form of unilamellar liposomes of well-defined composition and found that chlorpromazine interacts strongly with lipid bilayers of different composition leading to increased permeability. This implies that chlorpromazine can change influx properties of membranes hence suggesting that chlorpromazine may be a promising chemosensitizing compound for enhancing the cytotoxic effect of tamoxifen.
Collapse
|
24
|
D'Elia P, De Matteis F, Dragoni S, Shah A, Sgaragli G, Valoti M. DP7, a novel dihydropyridine multidrug resistance reverter, shows only weak inhibitory activity on human CYP3A enzyme(s). Eur J Pharmacol 2009; 614:7-13. [DOI: 10.1016/j.ejphar.2009.04.019] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2008] [Revised: 04/07/2009] [Accepted: 04/08/2009] [Indexed: 10/20/2022]
|
25
|
Mealey KL. Canine ABCB1 and macrocyclic lactones: Heartworm prevention and pharmacogenetics. Vet Parasitol 2008; 158:215-22. [DOI: 10.1016/j.vetpar.2008.09.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
|
26
|
Miller DS, Bauer B, Hartz AMS. Modulation of P-glycoprotein at the blood-brain barrier: opportunities to improve central nervous system pharmacotherapy. Pharmacol Rev 2008; 60:196-209. [PMID: 18560012 DOI: 10.1124/pr.107.07109] [Citation(s) in RCA: 246] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Pharmacotherapy of central nervous system (CNS) disorders (e.g., neurodegenerative diseases, epilepsy, brain cancer, and neuro-AIDS) is limited by the blood-brain barrier. P-glycoprotein, an ATP-driven, drug efflux transporter, is a critical element of that barrier. High level of expression, luminal membrane location, multispecificity, and high transport potency make P-glycoprotein a selective gatekeeper of the blood-brain barrier and thus a primary obstacle to drug delivery into the brain. As such, P-glycoprotein limits entry into the CNS for a large number of prescribed drugs, contributes to the poor success rate of CNS drug candidates, and probably contributes to patient-to-patient variability in response to CNS pharmacotherapy. Modulating P-glycoprotein could therefore improve drug delivery into the brain. Here we review the current understanding of signaling mechanisms responsible for the modulation of P-glycoprotein activity/expression at the blood-brain barrier with an emphasis on recent studies from our laboratories. Using intact brain capillaries from rats and mice, we have identified multiple extracellular and intracellular signals that regulate this transporter; several signaling pathways have been mapped. Three pathways are triggered by elements of the brain's innate immune response, one by glutamate, one by xenobiotic-nuclear receptor (pregnane X receptor) interactions, and one by elevated beta-amyloid levels. Signaling is complex, with several pathways sharing common signaling elements [tumor necrosis factor (TNF) receptor 1, endothelin (ET) B receptor, protein kinase C, and nitric-oxide synthase), suggesting a regulatory network. Several pathways include autocrine/paracrine elements, involving release of the proinflammatory cytokine, TNF-alpha, and the polypeptide hormone, ET-1. Finally, several steps in signaling are potential therapeutic targets that could be used to modulate P-glycoprotein activity in the clinic.
Collapse
Affiliation(s)
- David S Miller
- Laboratory of Pharmacology and Chemistry, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA.
| | | | | |
Collapse
|
27
|
Mealey KL, Gay JM, Martin LG, Waiting DK. Comparison of the hypothalamic?pituitary?adrenal axis in MDR1-1? and MDR1 wildtype dogs. J Vet Emerg Crit Care (San Antonio) 2007. [DOI: 10.1111/j.1476-4431.2006.00196.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
28
|
Foroutan B, Ruf AA, Costall B, Anderson D. An in vitro model to study chemoresistance in non-Hodgkin's lymphoma patients over-expressing mutant p53. J Pharmacol Toxicol Methods 2006; 55:151-8. [PMID: 16870476 DOI: 10.1016/j.vascn.2006.05.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2006] [Accepted: 05/23/2006] [Indexed: 11/20/2022]
Abstract
INTRODUCTION P-Glycoprotein plays a major role in regulating the concentration of chemotherapeutic agents inside the cytoplasm of normal and cancerous cells. The present in vitro study has primarily focused on the evaluation of the chemosensitising drug model, verapamil, as a P-glycoprotein antagonist not only to overcome chemoresistance in non-Hodgkin's lymphoma (NHL) chemoresistant cells (p53(+) i.e. over-expressing p53 mutant protein NHL cells) but also to evaluate and suggest the use of the single cell gel electrophoresis (SCGE) assay in the clinical setting. METHODS Leucocytes from CHOP-chemoresistant NHL patients (p53(+) cells) were examined in the SCGE assay. Altered levels of DNA damage (tail moments) were determined by the assay not only in the leucocytes from clinical samples, but also in the Raji cell sub-lines (NHL model) which are also over-expressing p53 mutant protein. In addition, as a comparison, P-glycoprotein was examined in normal human leucocytes and Raji cells. RESULTS Verapamil increased the tail moments induced by doxorubicin in all cell types over-expressing p53 mutant protein. DISCUSSION The assay was successful for evaluating P-glycoprotein regulation. This suggests the applicability at the cellular level of the method as suitable for use in the clinical setting since it is reliable and could be used pre-clinically or perhaps instead of or alongside clinical trails. Cells from patients with a chemoresistant disease state or whose disease relapses subsequently could be treated with such novel experimental therapies in vitro to determine the necessity for the individual administration of a P-glycoprotein antagonist.
Collapse
MESH Headings
- ATP Binding Cassette Transporter, Subfamily B, Member 1/antagonists & inhibitors
- ATP Binding Cassette Transporter, Subfamily B, Member 1/metabolism
- Adolescent
- Aged
- Aged, 80 and over
- Antineoplastic Combined Chemotherapy Protocols/pharmacology
- Caco-2 Cells
- Comet Assay/methods
- Cyclophosphamide/pharmacology
- DNA Damage
- Doxorubicin/pharmacology
- Drug Resistance, Neoplasm/drug effects
- Drug Resistance, Neoplasm/genetics
- Female
- Fluorouracil/pharmacology
- Gene Expression Regulation, Neoplastic/drug effects
- Humans
- Leukocytes/metabolism
- Lymphoma, Non-Hodgkin/drug therapy
- Lymphoma, Non-Hodgkin/genetics
- Lymphoma, Non-Hodgkin/metabolism
- Male
- Mutation
- Prednisone/pharmacology
- Tumor Suppressor Protein p53/genetics
- Tumor Suppressor Protein p53/metabolism
- Verapamil/pharmacology
- Vincristine/pharmacology
Collapse
Affiliation(s)
- Behzad Foroutan
- Department of Biomedical Sciences, School of Life Sciences, University of Bradford BD7 1DP, UK
| | | | | | | |
Collapse
|
29
|
Katragadda S, Budda B, Anand BS, Mitra AK. Role of efflux pumps and metabolising enzymes in drug delivery. Expert Opin Drug Deliv 2005; 2:683-705. [PMID: 16296794 DOI: 10.1517/17425247.2.4.683] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The impact of efflux pumps and metabolic enzymes on the therapeutic activity of various drugs has been well established. The presence of efflux pumps on various tissues and tumours has been shown to regulate the intracellular concentration needed to achieve therapeutic activity. The notable members of efflux proteins include P-glycoprotein, multi-drug resistance protein and breast cancer resistance protein. These efflux pumps play a pivotal role not only in extruding xenobiotics but also in maintaining the body's homeostasis by their ubiquitous presence and ability to coordinate among themselves. In this review, the role of efflux pumps in drug delivery and the importance of their tissue distribution is discussed in detail. To improve pharmacokinetic parameters of substrates, various strategies that modulate the activity of efflux proteins are also described. Drug metabolising enzymes mainly include the cytochrome P450 family of enzymes. Extensive drug metabolism due to the this family of enzymes is the leading cause of therapeutic inactivity. Therefore, the role of metabolising enzymes in drug delivery and disposition is extensively discussed in this review. The synergistic relationship between metabolising enzymes and efflux proteins is also described in detail. In summary, this review emphasises the urgent need to make changes in drug discovery and drug delivery as efflux pumps and metabolising enzymes play an important role in drug delivery and disposition.
Collapse
Affiliation(s)
- Suresh Katragadda
- University of Missouri-Kansas City, Division of Pharmaceutical Sciences, School of Pharmacy, 64110-2499, USA
| | | | | | | |
Collapse
|
30
|
Hua J, Mutch DG, Herzog TJ. Stable suppression of MDR-1 gene using siRNA expression vector to reverse drug resistance in a human uterine sarcoma cell line. Gynecol Oncol 2005; 98:31-8. [PMID: 15921732 DOI: 10.1016/j.ygyno.2005.03.042] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2005] [Revised: 01/10/2005] [Accepted: 03/13/2005] [Indexed: 11/24/2022]
Abstract
OBJECTIVE Chemotherapy is highly effective in treating a number of gynecologic malignancies; however, its effectiveness diminishes with repeated exposures due to the emergence of multi-drug resistance (MDR). The aim of this study was to establish a permanent MDR gene knockdown model via infection with the siRNA-hairpin expression vector. The impact of transfecting the RNAi upon MDR-1 mRNA and P-glycoprotein expression as well as resultant chemotherapy resistance was assessed. METHODS Multi-drug resistant cell line MES-SA/DX5 was transfected with the siRNA-hairpin expression vector (pSMDR-HYG) designed to target MDR-1 mRNA. A negative control was established utilizing a vector lacking the anti-sense component (pSCON-HYG). The LD(50) of doxorubicin for the stable transfectants was determined utilizing a cytotoxic MTT assay. The mRNA expression of MDR-1 gene among those cell lines was evaluated by semi-quantitative RT-PCR. The product of P-glycoprotein (P-gp) was examined by Western blotting hybridization and immunostaining. RESULTS Two stable transfected cell lines: MES-SA/DX5-M (with pSMDR-HYG) and MES-SA/DX5-C (with pSCON-HYG) were established. The cell line MES-SA/DX5-M was nearly 7 times more sensitive to doxorubicin than MES-SA/DX5-C and its parent cell line MES-SA/DX5 (P < 0.01). The mRNA expression of the MDR-1 gene in MES-SA/DX5-M was also statistically significantly lower than in the other 2 cell lines (P < 0.01) as assessed by semi-quantitative RT-PCR. A barely detectable signal for P-gp (170 kDa) was observed in MES-SA/DX5-M. The vast majority of MES-SA/DX5-M cells were immunohistochemically negative for P-gp. CONCLUSIONS Stable, sequence-specific MDR-1 gene silencing can be demonstrated by inducing the endogenous expression of hairpin siRNA. Hairpin-siRNA-based MDR-1 gene silencing correlated with decreased levels of MDR-1 mRNA and P-gp, thereby restoring permanent native chemosensitivity. This methodologic strategy may have significant clinical impact in reversing chemo-resistance, especially the multi-drug-resistant phenotype, in the treatment of gynecologic malignancies.
Collapse
MESH Headings
- ATP Binding Cassette Transporter, Subfamily B, Member 1/antagonists & inhibitors
- ATP Binding Cassette Transporter, Subfamily B, Member 1/biosynthesis
- ATP Binding Cassette Transporter, Subfamily B, Member 1/genetics
- Base Sequence
- Cell Line, Tumor
- Cinnamates/pharmacology
- Doxorubicin/pharmacology
- Drug Resistance, Multiple/genetics
- Drug Resistance, Neoplasm
- Female
- Gene Expression Regulation, Neoplastic
- Gene Silencing
- Genes, MDR
- Genetic Vectors/genetics
- Humans
- Hygromycin B/analogs & derivatives
- Hygromycin B/pharmacology
- Molecular Sequence Data
- RNA Interference
- RNA, Messenger/antagonists & inhibitors
- RNA, Messenger/genetics
- RNA, Small Interfering/genetics
- Sarcoma/drug therapy
- Sarcoma/genetics
- Sarcoma/metabolism
- Transfection
- Uterine Neoplasms/drug therapy
- Uterine Neoplasms/genetics
- Uterine Neoplasms/metabolism
Collapse
Affiliation(s)
- Jun Hua
- Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, Washington University School of Medicine, Box 8064, 4911 Barnes Hospital Plaza, St. Louis, MO 63110, USA
| | | | | |
Collapse
|
31
|
Walgren RA, McLeod HL. Small inhibitory RNA – a tool for credentialing candidate genes. Pharmacogenomics 2005; 6:281-92. [PMID: 16013959 DOI: 10.1517/14622416.6.3.281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
The effect of a drug is related to the interaction of the numerous gene products that participate in a drug pathway. The clinical importance of genetic variability on the overall outcome of most drug pathways remains to be determined. As a result, there is a need to efficiently identify the genes that not only participate in the pathway but also play a significant role in regulating the effects of a drug. The emerging technique of specific gene silencing through RNA interference initiated by small inhibitory RNA may prove to be a useful and powerful tool in the credentialing of candidate genes in drug pathways.
Collapse
|
32
|
Abstract
The pathogenesis underlying pharmacoresistance in epilepsy is unclear. One of the candidate mechanisms that has attracted growing interest is the limitation of antiepileptic drug (AED) access to the seizure focus by a range of efflux transporters, the prototype of which is P-glycoprotein (P-gp). P-gp is encoded by the multidrug resistance (MDR1 or ABCB1) gene. Predominantly expressed in organs with excretory functions and at blood-tissue barriers, P-gp is thought to act as a physiologic defense by extruding xenobiotics from mammalian cells and affording protection of sensitive organs. The high level of P-gp in the cerebrovascular endothelium is believed to contribute to the functionality of the blood-brain barrier. Overexpression of P-gp causes multidrug resistance in certain cancers. It has been hypothesized that overexpression of P-gp and other efflux transporters in the cerebrovascular endothelium, in the region of the epileptic focus, also may lead to drug resistance in epilepsy. This hypothesis is supported by the findings of elevated expression of efflux transporters in epileptic foci in patients with drug-resistant epilepsy, induction of expression by seizures in animal models, and experimental evidence that some commonly used AEDs are substrates. Conflicting reports suggest a possible association between variants of the MDR1 gene and medical intractability in epilepsy. Further studies to delineate the exact role, if any, of P-gp and other efflux transporters in drug-resistant epilepsy are warranted.
Collapse
Affiliation(s)
- Patrick Kwan
- Division of Neurology, Department of Medicine & Therapeutics, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong.
| | | |
Collapse
|
33
|
Hansen TWR. Recent advances in the pharmacotherapy for hyperbilirubinaemia in the neonate. Expert Opin Pharmacother 2005; 4:1939-48. [PMID: 14596647 DOI: 10.1517/14656566.4.11.1939] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Jaundice is a common cause for diagnostic works-up and therapeutic intervention in neonates. This is motivated by the risk for severe neurological sequelae (kernicterus). The mainstays of treatment for the past decades have been exchange transfusion and phototherapy. Exchange transfusion is now becoming rare due to immune prophylaxis in Rhesus-negative women, and treatment of sensitised infants with intravenous immunoglobulin. Several different pharmacological approaches have been studied as far as the treatment of neonatal jaundice. Of these, the focus of attention in recent years has been on the haem oxygenase inhibitors (metal meso- and protoporphyrins). These are effective inhibitors of bilirubin production and have been shown to significantly reduce peak serum bilirubin levels in several clinical trials, both when used prophylactically and therapeutically. However, questions remain regarding long-term safety, as well as the advisability of whole-scale inhibition of bilirubin production. Nevertheless, in selected infants with a high risk of severe jaundice, the use of haem oxygenase inhibitors may be acceptable. Pharmacotherapy in jaundiced infants is fraught with risks, as many drugs may increase the entry of bilirubin into the brain and presumably, the risk for neurotoxicity. Both the displacement of bilirubin from its albumin binding and interference with the function of phosphoglycoprotein in the blood-brain barrier are documented mechanisms in this respect.
Collapse
|
34
|
Abstract
Drug transporters significantly influence drug pharmacokinetics and pharmacodynamics. P-glycoprotein (P-gp), the product of the MDR1 (ABCB1) gene, is among the most well-characterized drug transporters, particularly in veterinary medicine. A number of clinically relevant, structurally and functionally unrelated drugs are substrates for P-gp. P-gp is expressed by a variety of normal tissues including the intestines, renal tubular cells, brain capillary endothelial cells, biliary canalicular cells, and others, where it functions to actively extrude substrate drugs. In this capacity, P-gp limits oral absorption and central nervous system entry of many substrate drugs. A number of MDR1 polymorphisms have been described in human patients, some of which result in altered drug pharmacokinetics and susceptibility to diseases such as Parkinson's disease, inflammatory bowel disease, refractory seizures, and others. An MDR1 polymorphism in herding breed dogs, including collies and Australian shepherds, has been demonstrated to be the cause of ivermectin sensitivity in these breeds. Recent evidence suggests that this polymorphism, a 4-bp deletion mutation, results in increased susceptibility to the toxicity of several drugs in addition to ivermectin. Furthermore, data in rodent models suggest that P-gp may play an important role in regulating the hypothalamic-pituitary-adrenal axis.
Collapse
Affiliation(s)
- K L Mealey
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Washington State University, Pullman, WA 99164-6610, USA.
| |
Collapse
|
35
|
Borges-Walmsley MI, McKeegan KS, Walmsley AR. Structure and function of efflux pumps that confer resistance to drugs. Biochem J 2003; 376:313-38. [PMID: 13678421 PMCID: PMC1223791 DOI: 10.1042/bj20020957] [Citation(s) in RCA: 171] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2002] [Revised: 08/04/2003] [Accepted: 09/18/2003] [Indexed: 11/17/2022]
Abstract
Resistance to therapeutic drugs encompasses a diverse range of biological systems, which all have a human impact. From the relative simplicity of bacterial cells, fungi and protozoa to the complexity of human cancer cells, resistance has become problematic. Stated in its simplest terms, drug resistance decreases the chance of providing successful treatment against a plethora of diseases. Worryingly, it is a problem that is increasing, and consequently there is a pressing need to develop new and effective classes of drugs. This has provided a powerful stimulus in promoting research on drug resistance and, ultimately, it is hoped that this research will provide novel approaches that will allow the deliberate circumvention of well understood resistance mechanisms. A major mechanism of resistance in both microbes and cancer cells is the membrane protein-catalysed extrusion of drugs from the cell. Resistant cells exploit proton-driven antiporters and/or ATP-driven ABC (ATP-binding cassette) transporters to extrude cytotoxic drugs that usually enter the cell by passive diffusion. Although some of these drug efflux pumps transport specific substrates, many are transporters of multiple substrates. These multidrug pumps can often transport a variety of structurally unrelated hydrophobic compounds, ranging from dyes to lipids. If we are to nullify the effects of efflux-mediated drug resistance, we must first of all understand how these efflux pumps can accommodate a diverse range of compounds and, secondly, how conformational changes in these proteins are coupled to substrate translocation. These are key questions that must be addressed. In this review we report on the advances that have been made in understanding the structure and function of drug efflux pumps.
Collapse
Affiliation(s)
- M Ines Borges-Walmsley
- Centre for Infectious Diseases, Department of Biological Sciences, Wolfson Research Institute, University of Durham - Stockton Campus, Stockton-on-Tees TS17 6BH, UK
| | | | | |
Collapse
|
36
|
Hankø E, Tommarello S, Watchko JF, Hansen TWR. Administration of drugs known to inhibit P-glycoprotein increases brain bilirubin and alters the regional distribution of bilirubin in rat brain. Pediatr Res 2003; 54:441-5. [PMID: 12904601 DOI: 10.1203/01.pdr.0000085169.87948.b6] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
P-glycoprotein (P-gp) is an ATP-dependent integral plasma membrane efflux pump, expressed in abundance in brain capillary endothelial cells and astrocytes. P-gp contributes to the blood-brain barrier in limiting the influx and retention of a variety of lipophilic compounds, including unconjugated bilirubin. Several drugs block P-gp function and thereby enhance intracellular accumulation of P-gp substrates. In this study we proposed that pretreatment with drugs known to inhibit P-gp function in clinically relevant doses would alter the uptake of bilirubin in the brain of 32- to 36-d-old rats. In the first arm of the study, the animals received pretreatment with an i.v. infusion of either propanolol, erythromycin, verapamil, ceftriaxone, rifampin, or saline, 10 min before an i.v. bolus of 50 mg/kg bilirubin was given. Except for the erythromycin-treated rats, all treatment groups had significantly higher brain-to-serum bilirubin ratios than control animals (p < 0.05, Welch's t test). In the second arm of the study, treatment with either ceftriaxone or rifampin or saline i.v. preceded a 50 mg/kg i.v. bolus of radioactive bilirubin. Analysis of seven different brain regions by scintillation counting showed that the distribution patterns differed significantly between the study groups (p < 0.001, ANOVA), however, not in accordance with a kernicteric staining pattern. Because of limited knowledge of expression and function of P-gp and other membrane transport proteins in the newborn, the implications of this study remain to be seen. We speculate that drugs known to inhibit P-gp function may increase the risk of bilirubin encephalopathy in the hyperbilirubinemic infant.
Collapse
Affiliation(s)
- Erik Hankø
- Department of Pediatrics, Rikshospitalet, N-0027 Oslo, Norway
| | | | | | | |
Collapse
|
37
|
Maki N, Hafkemeyer P, Dey S. Allosteric modulation of human P-glycoprotein. Inhibition of transport by preventing substrate translocation and dissociation. J Biol Chem 2003; 278:18132-9. [PMID: 12642584 DOI: 10.1074/jbc.m210413200] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The human multidrug transporter P-glycoprotein (Pgp, ABCB1) contributes to the poor bioavailability of many anticancer and antimicrobial agents as well as to drug resistance at the cellular level. For rational design of effective Pgp inhibitors, a clear understanding of its mechanism of action and functional regulation is essential. In this study, we demonstrate that inhibition of Pgp-mediated drug transport by cis-(Z)-flupentixol, a thioxanthene derivative, occurs through an allosteric mechanism. Unlike competitive inhibitors, such as cyclosporin A and verapamil, cis-(Z)-flupentixol does not interfere with substrate ([(125)I]iodoarylazidoprazosin) recognition by Pgp, instead it prevents substrate translocation and dissociation, resulting in a stable but reversible Pgp-substrate complex. cis-(Z)-Flupentixol-induced complex formation requires involvement of the Pgp substrate site, because agents that either physically compete (cyclosporin A) for or indirectly occlude (vanadate) the substrate-binding site prevent formation of the complex. Allosteric modulation by cis-(Z)-flupentixol involves a conformational change in Pgp detectable by monoclonal antibody UIC2 binding to a conformation-sensitive external epitope of Pgp. The conformational change observed is distinct from that induced by Pgp substrates or competitive inhibitors. A single amino acid substitution (F983A) in TM12 of Pgp that impairs inhibition by cis-(Z)-flupentixol of Pgp-mediated drug transport also affects stabilization of the Pgp-substrate complex as well as the characteristic conformational change. Taken together, our results describe the molecular mechanism by which the Pgp modulator cis-(Z)-flupentixol allosterically inhibits drug transport.
Collapse
Affiliation(s)
- Nazli Maki
- Department of Biochemistry and Molecular Biology, Uniformed Services University of the Health Sciences, F. Edward Hébert School of Medicine, Bethesda, Maryland 20814-4799, USA
| | | | | |
Collapse
|
38
|
Abstract
A subset of cellular compartments maintain acidic interior environments that are critical for the specific functions of each organelle and for cell growth and survival in general. The pH of each organelle reflects the balance between proton pumping, counterion conductance, and proton leak. Alterations in steady-state organelle pH due to defects in either proton pumping activity or counterion conductance have been suggested to contribute to the pathology of several diseases; however, definitive evidence remains elusive. This review describes recent evidence for the misregulation of organelle pH in the progression of cancer, Dent's disease, and cystic fibrosis.
Collapse
Affiliation(s)
- Ora A Weisz
- Renal-Electrolyte Division, University of Pittsburgh School of Medicine, 3550 Terrace St., Pittsburgh, PA 15261, USA.
| |
Collapse
|
39
|
Enokida H, Gotanda T, Oku S, Imazono Y, Kubo H, Hanada T, Suzuki S, Inomata K, Kishiye T, Tahara Y, Nishiyama K, Nakagawa M. Reversal of P-glycoprotein-mediated paclitaxel resistance by new synthetic isoprenoids in human bladder cancer cell line. Jpn J Cancer Res 2002; 93:1037-46. [PMID: 12359058 PMCID: PMC5927134 DOI: 10.1111/j.1349-7006.2002.tb02481.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
We isolated a paclitaxel-resistant cell line (KK47/TX30) from a human bladder cancer cell line (KK47/WT) in order to investigate the mechanism of and reversal agents for paclitaxel resistance. KK47/TX30 cells exhibited 700-fold resistance to paclitaxel and cross-resistance to vinca alkaloids and topoisomerase II inhibitors. Tubulin polymerization assay showed no significant difference in the ratio of polymerized alpha- and beta-tubulin between KK47/WT and KK47/TX30 cells. Western blot analysis demonstrated overexpression of P-glycoprotein (P-gp) and lung resistance-related protein (LRP) in KK47/TX30 cells. Drug accumulation and efflux studies showed that the decreased paclitaxel accumulation in KK47/TX30 cells was due to enhanced paclitaxel efflux. Cell survival assay revealed that verapamil and cepharanthine, conventional P-gp modulators, could completely overcome paclitaxel resistance. To investigate whether new synthetic isoprenoids could overcome paclitaxel resistance, we synthesized 31 isoprenoids based on the structure of N-solanesyl-N,N'-bis(3,4-dimethoxybenzyl)ethylenediamine (SDB), which could reverse multidrug resistance (MDR), as shown previously. Among those examined, trans-N,N'-bis(3,4-dimethoxybenzyl)-N-solanesyl-1,2-diaminocyclohexane (N-5228) could completely reverse paclitaxel resistance in KK47/TX30 cells. N-5228 inhibited photoaffinity labeling of P-gp by [(3)H]azidopine, suggesting that N-5228 could bind to P-gp directly and could be a substrate of P-gp. Next, we investigated structural features of these 31 isoprenoids in order to determine the structural requirements for the reversal of P-gp-mediated paclitaxel resistance, suggesting that the following structural features are important for overcoming paclitaxel resistance: (1) a basic structure of 8 to 10 isoprene units, (2) a cyclohexane ring or benzene ring within the framework, (3) two cationic sites in close proximity to each other, and (4) a benzyl group with 3,4-dimethoxy functionalities, which have moderate electron-donating ability. These findings may provide valuable information for the development of P-gp-mediated MDR-reversing agents.
Collapse
Affiliation(s)
- Hideki Enokida
- Department of Urology, Faculty of Medicine, Kagoshima University, Kagoshima 890-8520, Japan.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
40
|
Teodori E, Dei S, Scapecchi S, Gualtieri F. The medicinal chemistry of multidrug resistance (MDR) reversing drugs. FARMACO (SOCIETA CHIMICA ITALIANA : 1989) 2002; 57:385-415. [PMID: 12058813 DOI: 10.1016/s0014-827x(02)01229-6] [Citation(s) in RCA: 131] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Multidrug resistance (MDR) is a kind of resistance of cancer cells to multiple classes of chemotherapic drugs that can be structurally and mechanistically unrelated. Classical MDR regards altered membrane transport that results in lower cell concentrations of cytotoxic drug and is related to the over expression of a variety of proteins that act as ATP-dependent extrusion pumps. P-glycoprotein (Pgp) and multidrug resistance protein (MRP1) are the most important and widely studied members of the family that belongs to the ABC superfamily of transporters. It is apparent that, besides their role in cancer cell resistance, these proteins have multiple physiological functions as well, since they are expressed also in many important non-tumoural tissues and are largely present in prokaryotic organisms. A number of drugs have been identified which are able to reverse the effects of Pgp, MRPI and sister proteins, on multidrug resistance. The first MDR modulators discovered and studied in clinical trials were endowed with definite pharmacological actions so that the doses required to overcome MDR were associated with unacceptably high side effects. As a consequence, much attention has been focused on developing more potent and selective modulators with proper potency, selectivity and pharmacokinetics that can be used at lower doses. Several novel MDR reversing agents (also known as chemosensitisers) are currently undergoing clinical evaluation for the treatment of resistant tumours. This review is concerned with the medicinal chemistry of MDR reversers, with particular attention to the drugs that are presently in development.
Collapse
Affiliation(s)
- E Teodori
- Dipartimento di Scienze Farmaceutiche, Universita' di Firenze, Florence, Italy
| | | | | | | |
Collapse
|
41
|
Prié D, Couette S, Fernandes I, Silve C, Friedlander G. P-glycoprotein inhibitors stimulate renal phosphate reabsorption in rats. Kidney Int 2001; 60:1069-76. [PMID: 11532101 DOI: 10.1046/j.1523-1755.2001.0600031069.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Dipyridamole (Dip) was previously shown to increase renal phosphate (Pi) reabsorption in humans. However, the mechanism(s) underlying this renal tubular effect is not fully elucidated. It is known that Dip inhibits the activity of the P-glycoprotein (Pgp) multidrug resistance protein 1 (MDR1) expressed on the apical membrane of renal proximal tubular cells where the Na-Pi cotransporter (NPT2) is also expressed. We hypothesized that Dip could increase renal Pi reabsorption by inhibiting Pgp activity. METHODS To test this hypothesis, the effects of Dip, verapamil (Ver), and cyclosporine A (CsA), three unrelated Pgp inhibitors, were studied on the renal Pi reabsorption in rats. RESULTS All three drugs decreased the fractional excretion of Pi (FE(Pi)) in a dose-dependent manner within one hour after beginning the drug infusion, without altering the glomerular filtration rate or serum parathyroid hormone concentration. Sodium-dependent Pi uptake but not Na-glucose transport was increased in brush-border membrane vesicles (BBMVs) when comparing treated with untreated rats. Western blot analysis showed that NPT2 protein was increased in BBMVs from treated rats. Dip and Ver had no effect when applied directly to BBMVs prepared from untreated rats. Pretreatment of rats with colchicine prevented the effects of Dip on the FE(Pi) and NPT2 expression in brush-border membranes. CONCLUSIONS Our results suggest that inhibition of Pgp in the proximal tubule increases Pi uptake and NPT2 translocation to the apical membrane.
Collapse
Affiliation(s)
- D Prié
- INSERM U426 and Department of Physiology, Faculté de Médecine Xavier Bichat, Université Paris 7, France.
| | | | | | | | | |
Collapse
|
42
|
Lo YL. Phospholipids as multidrug resistance modulators of the transport of epirubicin in human intestinal epithelial Caco-2 cell layers and everted gut sacs of rats. Biochem Pharmacol 2000; 60:1381-90. [PMID: 11008132 DOI: 10.1016/s0006-2952(00)00451-2] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Phospholipids have been increasingly used as carriers for the delivery of a variety of drugs. Studies using cancer chemotherapeutic agents such as epirubicin encapsulated in liposomes, which are made of phospholipids and other ingredients, have generally shown reduced toxicity and enhanced therapeutic efficacy. The recent investigation of the role of P-glycoprotein (P-gp) in phospholipid translocation has opened a new area of research on the possible use of phospholipids as multidrug resistance (MDR) modulators. This study investigated the effects of liposomal encapsulation, empty liposome pretreatment, or free lipid pretreatment on the uptake and transport of epirubicin in the human colon adenocarcinoma cell line Caco-2 and in everted gut sacs of rat jejunum and ileum. Epirubicin uptake experiments, using a flow cytometer, showed that both liposomal encapsulation and empty liposome pretreatment increased the intracellular accumulation of epirubicin in Caco-2 cells significantly. These two treatments substantially increased apical-to-basolateral absorption of epirubicin across Caco-2 monolayers and markedly improved mucosal-to-serosal absorption of epirubicin in rat jejunum and ileum. Enhancement also was observed with both liposome encapsulation and empty liposome pretreatment in the reduction of basolateral-to-apical efflux of epirubicin across Caco-2 monolayers. However, because diffusion of free dipalmitoyl phosphatidylcholine (DPPC) or dipalmitoyl phosphatidylethanolamine (DPPE) lipids across the cell membrane is very slow, these free lipids showed marginal effects on absorption and/or secretion of epirubicin in both Caco-2 cells and rat gut sacs. The study suggests that inhibition of P-gp or other transporter proteins located in the intestines may be partially involved in the reduction of epirubicin efflux. In conclusion, the therapeutic efficacy of epirubicin may be improved by using phospholipids as excipients and MDR modulators in the formulations. Liposomal formulations may have important applications to circumvent drug resistance in cancer chemotherapy.
Collapse
Affiliation(s)
- Y L Lo
- Department of Pharmacy, Chia Nan University of Pharmacy and Science, Tainan Hsien, Taiwan 717, Republic of China.
| |
Collapse
|
43
|
Krishna R, Mayer LD. Multidrug resistance (MDR) in cancer. Mechanisms, reversal using modulators of MDR and the role of MDR modulators in influencing the pharmacokinetics of anticancer drugs. Eur J Pharm Sci 2000; 11:265-83. [PMID: 11033070 DOI: 10.1016/s0928-0987(00)00114-7] [Citation(s) in RCA: 719] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
In recent years, there has been an increased understanding of P-glycoprotein (P-GP)-mediated pharmacokinetic interactions. In addition, its role in modifying the bioavailability of orally administered drugs via induction or inhibition has been also been demonstrated in various studies. This overview presents a background on some of the commonly documented mechanisms of multidrug resistance (MDR), reversal using modulators of MDR, followed by a discussion on the functional aspects of P-GP in the context of the pharmacokinetic interactions when multiple agents are coadministered. While adverse pharmacokinetic interactions have been documented with first and second generation MDR modulators, certain newer agents of the third generation class of compounds have been less susceptible in eliciting pharmacokinetic interactions. Although the review focuses on P-GP and the pharmacology of MDR reversal using MDR modulators, relevance of these drug transport proteins in the context of pharmacokinetic implications (drug absorption, distribution, clearance, and interactions) will also be discussed.
Collapse
Affiliation(s)
- R Krishna
- Department of Advanced Therapeutics, British Columbia Cancer Agency, BC V5Z 4E6, Vancouver, Canada.
| | | |
Collapse
|
44
|
Abstract
Active efflux from procaryotic as well as eucaryotic cells strongly modulates the activity of a large number of antibiotics. Effective antibiotic transport has now been observed for many classes of drug efflux pumps. Thus, within the group of primary active transporters, predominant in eucaryotes, six families belonging to the ATP-binding cassette superfamily, and including the P-glycoprotein in the MDR (Multi Drug Resistance) group and the MRP (Multidrug Resistance Protein), have been recognized as being responsible for antibiotic efflux. Within the class of secondary active transporters (antiports, symports, and uniports), ten families of antibiotic efflux pumps have been described, distributed in five superfamilies [SMR (Small Multidrug Resistance), MET (Multidrug Endosomal Transporter), MAR (Multi Antimicrobial Resistance), RND (Resistance Nodulation Division), and MFS (Major Facilitator Superfamily)]. Nowadays antibiotic efflux pumps are believed to contribute significantly to acquired bacterial resistance because of the very broad variety of substrates they recognize, their expression in important pathogens, and their cooperation with other mechanisms of resistance. Their presence also explains high-level intrinsic resistances found in specific organisms. Stable mutations in regulatory genes can produce phenotypes of irreversible multidrug resistance. In eucaryotes, antibiotic efflux pumps modulate the accumulation of antimicrobials in phagocytic cells and play major roles in their transepithelial transport. The existence of antibiotic efflux pumps, and their impact on therapy, must now be taken fully into account for the selection of novel antimicrobials. The design of specific, potent inhibitors appears to be an important goal for the improved control of infectious diseases in the near future.
Collapse
Affiliation(s)
- F Van Bambeke
- Unité de Pharmacologie Cellulaire et Moléculaire, Université Catholique de Louvain, Brussels, Belgium.
| | | | | |
Collapse
|
45
|
Marthinet E, Divita G, Bernaud J, Rigal D, Baggetto LG. Modulation of the typical multidrug resistance phenotype by targeting the MED-1 region of human MDR1 promoter. Gene Ther 2000; 7:1224-33. [PMID: 10918491 DOI: 10.1038/sj.gt.3301231] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Multidrug resistance of cancer (MDR) is the major cause of failure of chemotherapy. The typical MDR phenotype is due to the overexpression of membrane proteins among which the main representative is P-glycoprotein (Pgp) encoded by the MDR1 gene. Many attempts to modulate MDR by chemosensitizers have been unsuccessful in human therapy due to their intrinsic toxic effects. In an effort to modulate the MDR phenotype efficiently we designed an antisense and a transcriptional decoy strategy targeting the TATA-less human MDR1 gene promoter. The choice of the start point of transcription in a multiple start site window is related to an upstream MED-1 cis-element, the sequence and configuration of which are specific to human MDR1 gene expressed in Pgp-overproducing cancer cells. A 12mer antisense oligodeoxynucleotide (ODN) and a 12mer double-stranded ODN, both containing the MED-1 sequence, were designed and efficiently vectorized into the nucleus with the chimerical MPG peptide. A synthetic cellular model (NIH-EGFP) and highly resistant human CEM/VLB0.45 leukemia cells, significantly responded to transfection with the ODN/MPG complex. The level of EGFP fluorescence in NIH-EGFP cells decreased, and thus its production, and viability of CEM/VLB0.45 cells decreased by 63% in the presence of vinblastine, revealing that their resistance to the anticancer drug was reversed. These results open new insights into transcriptional decoy and anti-gene therapies of MDR cancers that overproduce Pgp. Gene Therapy (2000) 7, 1224-1233.
Collapse
|
46
|
Schmid D, Ecker G, Kopp S, Hitzler M, Chiba P. Structure-activity relationship studies of propafenone analogs based on P-glycoprotein ATPase activity measurements. Biochem Pharmacol 1999; 58:1447-56. [PMID: 10513988 DOI: 10.1016/s0006-2952(99)00229-4] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Propafenone analogs (PAs) were previously identified as potent inhibitors of P-glycoprotein (Pgp)-mediated toxin efflux. For this as well as other classes of Pgp inhibitors, lipophilicity as well as hydrogen bond acceptor strength are important determinants of biological activity. The question as to whether a direct interaction between PA-type modulators and Pgp takes place was addressed by means of Pgp ATPase measurements and transport studies. Propafenone-type modulators stimulated ATPase activity up to 2-fold over basal activity in a concentration-dependent biphasic manner. Within a series of structural homologs, Ka values of ATPase stimulation strongly correlated with lipophilicity. Analogs containing a quaternary nitrogen stimulated Pgp ATPase activity with lesser efficacy, while Ka values were somewhat higher when compared to corresponding tertiary analogs. Transport studies performed in inside-out plasma membrane (I/O) vesicles demonstrated that analogs containing a tertiary nitrogen rapidly associated with the biomembrane. Quaternary analogs, which are restricted by a permanent positive charge in transiting the plasma membrane by diffusion, accumulated in Pgp containing I/O vesicles in an ATP-dependent and cyclosporin A-inhibitable manner, which identified them as Pgp substrates. Identical structure-activity relationships were found in either Pgp ATPase stimulation experiments in I/O vesicles or in toxin efflux inhibition studies using intact cells. Therefore, differences in membrane transit are not responsible for the observed structure-activity relationships.
Collapse
Affiliation(s)
- D Schmid
- Institute of Medical Chemistry, University of Vienna, Austria
| | | | | | | | | |
Collapse
|
47
|
Sharom FJ, Yu X, Lu P, Liu R, Chu JW, Szabó K, Müller M, Hose CD, Monks A, Váradi A, Seprôdi J, Sarkadi B. Interaction of the P-glycoprotein multidrug transporter (MDR1) with high affinity peptide chemosensitizers in isolated membranes, reconstituted systems, and intact cells. Biochem Pharmacol 1999; 58:571-86. [PMID: 10413294 DOI: 10.1016/s0006-2952(99)00139-2] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
P-glycoprotein-mediated multidrug resistance can be reversed by the action of a group of compounds known as chemosensitizers. The interactions with P-glycoprotein of two novel hydrophobic peptide chemosensitizers (reversins 121 and 205) have been studied in model systems in vitro, and in a variety of MDR1-expressing intact tumor cells. The reversins bound to purified P-glycoprotein with high affinity (77-154 nM), as assessed by a quenching assay using fluorescently labeled purified protein. The peptides modulated P-glycoprotein ATPase activity in Sf9 insect cell membranes expressing human MDR1, plasma membrane vesicles from multidrug-resistant cells, and reconstituted proteoliposomes. Both peptides induced a large stimulation of ATPase activity; however, higher concentrations, especially of reversin 205, led to inhibition. This pattern was different from that of simple linear peptides, and resembled that of chemosensitizers such as verapamil. In both membrane vesicles and reconstituted proteoliposomes, 1-2 microM reversins were more effective than cyclosporin A at blocking colchicine transport. Reversin 121 and reversin 205 restored the uptake of [3H]daunorubicin and rhodamine 123 in MDR1-expressing cells to the level observed in the drug-sensitive parent cell lines, and also effectively inhibited the extrusion of calcein acetoxymethyl ester from intact cells. In cytotoxicity assays, reversin 121 and reversin 205 eliminated the resistance of MDR1-expressing tumor cells against MDR1-substrate anticancer drugs, and they had no toxic effects in MDR1-negative control cells. We suggest that peptides of the reversin type interact with the MDR1 protein with high affinity and specificity, and thus they may be good candidates for the development of MDR1-modulating agents to sensitize drug resistance in cancer.
Collapse
Affiliation(s)
- F J Sharom
- Guelph-Waterloo Centre for Graduate Work in Chemistry and Biochemistry, Department of Chemistry and Biochemistry, University of Guelph, Ontario, Canada.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
48
|
Perloff MD, von Moltke LL, Cotreau MM, Greenblatt DJ. Unchanged cytochrome P450 3A (CYP3A) expression and metabolism of midazolam, triazolam, and dexamethasone in mdr(-/-) mouse liver microsomes. Biochem Pharmacol 1999; 57:1227-32. [PMID: 10230766 DOI: 10.1016/s0006-2952(99)00054-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
P-Glycoprotein (P-gp) and cytochrome P450 3A (CYP3A) share common substrates and expression properties, but the relationship of mdrl deficiency to CYP3A-mediated metabolism and protein expression is not established. The in vitro kinetic parameters of CYP3A-mediated metabolism of midazolam (MDZ), triazolam (TRZ), and dexamethasone (DEX) were studied in liver microsomes from three mrdrla(-/-) mice, one mdrla/b(-/-) mouse, and mdrla/b(+/+) controls. The kinetic profiles of CYP3A-mediated MDZ 4-hydroxylation were not significantly different between mdrl-deficient animals and controls. Overall mean (+/- SEM, N = 8) values were: Vmax, 0.74+/-0.05 nmol/min/mg protein; Km, 28.2+/-2.7 microM; and estimated intrinsic clearance, 0.026+/-0.003 mL/min/mg protein. Likewise, rates of formation of alpha-OH- and 4-OH-TRZ (from 500 microM TRZ), and of DEX metabolites sensitive to ketoconazole inhibition, M1 and M5 (from 20 microM DEX), did not differ between mdrl-deficient and control animals. Immunoquantified microsomal CYP3A protein levels in mdrla(-/-), mdrla/b(-/-), and mdrla/b(+/+) mice were not different, with overall mean immunoreactive protein levels of 2.68+/-0.09 pmol/microg protein. Although CYP3A and P-gp share aspects of activity and expression, disruption of the mdrl genes does not affect CYP3A-mediated metabolism or protein expression in the mouse.
Collapse
Affiliation(s)
- M D Perloff
- Department of Pharmacology and Experimental Therapeutics, Tufts University School of Medicine, New England Medical Center Hospital, Boston, MA 02111, USA
| | | | | | | |
Collapse
|
49
|
Nakamura T, Oka M, Aizawa K, Soda H, Fukuda M, Terashi K, Ikeda K, Mizuta Y, Noguchi Y, Kimura Y, Tsuruo T, Kohno S. Direct interaction between a quinoline derivative, MS-209, and multidrug resistance protein (MRP) in human gastric cancer cells. Biochem Biophys Res Commun 1999; 255:618-24. [PMID: 10049760 DOI: 10.1006/bbrc.1999.0245] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
MS-209 is a novel quinoline derivative reversing P-glycoprotein-mediated multidrug resistance (MDR). We investigated the interaction between MS-209 and multidrug resistance protein (MRP) in MRP-overexpressing human gastric cancer cells. We measured [3H]leukotriene C4 uptake into the membrane vesicles of the cells and intracellular calcein and [3H]vincristine accumulation with or without MS-209. In multi-drug-resistant MKN45R0.8 cells selected by doxorubicin, MS-209 dose dependently reduced MRP-mediated [3H]leukotriene C4 uptake and increased calcein accumulation. In both resistant and unselected cell lines expressing the MRP gene, MS-209 increased [3H]vincristine accumulation in proportion with the level of MRP mRNA expression and enhanced the cytotoxicity of etoposide, doxorubicin, and vincristine. The reversal effects correlated with the level of MRP mRNA expression in these cells. Our results indicate that MS-209 effectively reverses intrinsic and acquired MRP-mediated MDR of gastric cancer cells by interacting directly with MRP.
Collapse
Affiliation(s)
- T Nakamura
- Second Department of Internal Medicine, Nagasaki University School of Medicine, Nagasaki, 852-8501, Japan
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
50
|
Morihira K, Nishimori T, Kusama H, Horiguchi Y, Kuwajima I, Tsuruo T. Synthesis of C-ring aromatic taxoids and evaluation of their multi-drug resistance reversing activity. Bioorg Med Chem Lett 1998; 8:2973-6. [PMID: 9873657 DOI: 10.1016/s0960-894x(98)00539-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The C-aromatic taxoids were synthesized to develop effective inhibitors against drug efflux mediated by p-glycoproteins. Among those tested using multi-drug resistant tumor cells (2780AD), the benzoate 11 exhibited significant activity as potent as verapamil, a well-established MDR reversing agent.
Collapse
Affiliation(s)
- K Morihira
- Department of Chemistry, Tokyo Institute of Technology, Japan
| | | | | | | | | | | |
Collapse
|