1
|
Tjeerdema E, Lee Y, Metry R, Hamdoun A. Semi-automated, high-content imaging of drug transporter knockout sea urchin (Lytechinus pictus) embryos. JOURNAL OF EXPERIMENTAL ZOOLOGY. PART B, MOLECULAR AND DEVELOPMENTAL EVOLUTION 2024; 342:313-329. [PMID: 38087422 DOI: 10.1002/jez.b.23231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 11/08/2023] [Accepted: 11/19/2023] [Indexed: 05/01/2024]
Abstract
A defining feature of sea urchins is their extreme fecundity. Urchins produce millions of transparent, synchronously developing embryos, ideal for spatial and temporal analysis of development. This biological feature has been effectively utilized for ensemble measurement of biochemical changes. However, it has been underutilized in imaging studies, where single embryo measurements are used. Here we present an example of how stable genetics and high content imaging, along with machine learning-based image analysis, can be used to exploit the fecundity and synchrony of sea urchins in imaging-based drug screens. Building upon our recently created sea urchin ABCB1 knockout line, we developed a high-throughput assay to probe the role of this drug transporter in embryos. We used high content imaging to compare accumulation and toxicity of canonical substrates and inhibitors of the transporter, including fluorescent molecules and antimitotic cancer drugs, in homozygous knockout and wildtype embryos. To measure responses from the resulting image data, we used a nested convolutional neural network, which rapidly classified embryos according to fluorescence or cell division. This approach identified sea urchin embryos with 99.8% accuracy and determined two-cell and aberrant embryos with 96.3% and 89.1% accuracy, respectively. The results revealed that ABCB1 knockout embryos accumulated the transporter substrate calcein 3.09 times faster than wildtypes. Similarly, knockouts were 4.71 and 3.07 times more sensitive to the mitotic poisons vinblastine and taxol. This study paves the way for large scale pharmacological screens in the sea urchin embryo.
Collapse
Affiliation(s)
- Evan Tjeerdema
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, USA
| | - Yoon Lee
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, USA
| | - Rachel Metry
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, USA
| | - Amro Hamdoun
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, USA
| |
Collapse
|
2
|
Mensah GAK, Schaefer KG, Roberts AG, King GM, Bartlett MG. Probing the Mechanisms Underlying the Transport of the Vinca Alkaloids by P-glycoprotein. J Pharm Sci 2024:S0022-3549(24)00098-4. [PMID: 38527618 DOI: 10.1016/j.xphs.2024.03.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 03/18/2024] [Accepted: 03/18/2024] [Indexed: 03/27/2024]
Abstract
The efficacy of many cancer drugs is hindered by P-glycoprotein (Pgp), a cellular pump that removes drugs from cells. To improve chemotherapy, drugs capable of evading Pgp must be developed. Despite similarities in structure, vinca alkaloids (VAs) show disparate Pgp-mediated efflux ratios. ATPase activity and binding affinity studies show at least two binding sites for the VAs: high- and low-affinity sites that stimulate and inhibit the ATPase activity rate, respectively. The affinity for ATP from the ATPase kinetics curve for vinblastine (VBL) at the high-affinity site was 2- and 9-fold higher than vinorelbine (VRL) and vincristine (VCR), respectively. Conversely, VBL had the highest Km (ATP) for the low-affinity site. The dissociation constants (KDs) determined by protein fluorescence quenching were in the order VBL < VRL< VCR. The order of the KDs was reversed at higher substrate concentrations. Acrylamide quenching of protein fluorescence indicate that the VAs, either at 10 µM or 150 µM, predominantly maintain Pgp in an open-outward conformation. When 3.2 mM AMPPNP was present, 10 µM of either VBL, VRL, or VCR cause Pgp to shift to an open-outward conformation, while 150 µM of the VAs shifted the conformation of Pgp to an intermediate orientation, between opened inward and open-outward. However, the conformational shift induced by saturating AMPPNP and VCR condition was less than either VBL or VRL in the presence of AMPPNP. At 150 µM, atomic force microscopy (AFM) revealed that the VAs shift Pgp population to a predominantly open-inward conformation. Additionally, STDD NMR studies revealed comparable groups in VBL, VRL, and VCR are in contact with the protein during binding. Our results, when coupled with VAs-microtubule structure-activity relationship studies, could lay the foundation for developing next-generation VAs that are effective as anti-tumor agents. A model that illustrates the intricate process of Pgp-mediated transport of the VAs is presented.
Collapse
Affiliation(s)
- Gershon A K Mensah
- Department of Pharmaceutical and Biomedical Science, University of Georgia, Athens, GA 30602, USA
| | - Katherine G Schaefer
- Department of Physics and Astronomy, University of Missouri, Columbia, MO 65211, USA
| | - Arthur G Roberts
- Department of Pharmaceutical and Biomedical Science, University of Georgia, Athens, GA 30602, USA.
| | - Gavin M King
- Department of Physics and Astronomy, University of Missouri, Columbia, MO 65211, USA; Joint with Biochemistry, University of Missouri, Columbia, MO 65211, USA.
| | - Michael G Bartlett
- Department of Pharmaceutical and Biomedical Science, University of Georgia, Athens, GA 30602, USA.
| |
Collapse
|
3
|
Paškevičiūtė M, Petrikaitė V. Effect of natural flavonoids to reverse P-glycoprotein-related multidrug resistance in breast cancer cell cultures. Am J Cancer Res 2022; 12:2526-2538. [PMID: 35812069 PMCID: PMC9251692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Accepted: 05/17/2022] [Indexed: 06/15/2023] Open
Abstract
The aim of the research was to evaluate the influence of two P-glycoprotein (P-gp) inhibitors silymarin and quercetin on anticancer drug doxorubicin (DOX) and pegylated liposomal doxorubicin (PLD) delivery into breast cancer cells (2D cultures) and cancer cell spheroids (3D cultures) at different pH. The cytotoxicity of the compounds was assessed using MTT assay. Spheroids were generated using magnetic 3D Bioprinting method. The uptake of DOX and PLD into monolayer-cultured cells and spheroids was assessed by fluorescence microscopy. Both tested flavonoids did not increase DOX and PLD levels into monolayer-cultured 4T1 cells and 4T1 cell spheroids. However, both silymarin and quercetin enhanced DOX and PLD uptake into JC cell cultures. Silymarin and quercetin may modulate DOX and PLD transport into monolayer-cultured cells and three-dimensional cancer cell cultures depending on P-gp activity.
Collapse
Affiliation(s)
- Miglė Paškevičiūtė
- Laboratory of Drug Targets Histopathology, Institute of Cardiology, Lithuanian University of Health SciencesSukilėlių pr. 13, LT-50162, Kaunas, Lithuania
| | - Vilma Petrikaitė
- Laboratory of Drug Targets Histopathology, Institute of Cardiology, Lithuanian University of Health SciencesSukilėlių pr. 13, LT-50162, Kaunas, Lithuania
- Institute of Physiology and Pharmacology, Faculty of Medicine, Lithuanian University of Health SciencesA. Mickevičiaus g. 9, LT-44307, Kaunas, Lithuania
| |
Collapse
|
4
|
Mechanistic basis for multidrug resistance and collateral drug sensitivity conferred to the malaria parasite by polymorphisms in PfMDR1 and PfCRT. PLoS Biol 2022; 20:e3001616. [PMID: 35507548 PMCID: PMC9067703 DOI: 10.1371/journal.pbio.3001616] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 03/31/2022] [Indexed: 01/16/2023] Open
Abstract
Polymorphisms in the Plasmodium falciparum multidrug resistance protein 1 (pfmdr1) gene and the Plasmodium falciparum chloroquine resistance transporter (pfcrt) gene alter the malaria parasite’s susceptibility to most of the current antimalarial drugs. However, the precise mechanisms by which PfMDR1 contributes to multidrug resistance have not yet been fully elucidated, nor is it understood why polymorphisms in pfmdr1 and pfcrt that cause chloroquine resistance simultaneously increase the parasite’s susceptibility to lumefantrine and mefloquine—a phenomenon known as collateral drug sensitivity. Here, we present a robust expression system for PfMDR1 in Xenopus oocytes that enables direct and high-resolution biochemical characterizations of the protein. We show that wild-type PfMDR1 transports diverse pharmacons, including lumefantrine, mefloquine, dihydroartemisinin, piperaquine, amodiaquine, methylene blue, and chloroquine (but not the antiviral drug amantadine). Field-derived mutant isoforms of PfMDR1 differ from the wild-type protein, and each other, in their capacities to transport these drugs, indicating that PfMDR1-induced changes in the distribution of drugs between the parasite’s digestive vacuole (DV) and the cytosol are a key driver of both antimalarial resistance and the variability between multidrug resistance phenotypes. Of note, the PfMDR1 isoforms prevalent in chloroquine-resistant isolates exhibit reduced capacities for chloroquine, lumefantrine, and mefloquine transport. We observe the opposite relationship between chloroquine resistance-conferring mutations in PfCRT and drug transport activity. Using our established assays for characterizing PfCRT in the Xenopus oocyte system and in live parasite assays, we demonstrate that these PfCRT isoforms transport all 3 drugs, whereas wild-type PfCRT does not. We present a mechanistic model for collateral drug sensitivity in which mutant isoforms of PfMDR1 and PfCRT cause chloroquine, lumefantrine, and mefloquine to remain in the cytosol instead of sequestering within the DV. This change in drug distribution increases the access of lumefantrine and mefloquine to their primary targets (thought to be located outside of the DV), while simultaneously decreasing chloroquine’s access to its target within the DV. The mechanistic insights presented here provide a basis for developing approaches that extend the useful life span of antimalarials by exploiting the opposing selection forces they exert upon PfCRT and PfMDR1.
Collapse
|
5
|
Liu J, Nagapudi K, Dolton MJ, Chiang PC. Utilizing Tiny-TIM to Assess the Effect of Acid-Reducing Agents on the Absorption of Orally Administered Drugs. J Pharm Sci 2021; 110:3020-3026. [PMID: 33940027 DOI: 10.1016/j.xphs.2021.04.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 04/21/2021] [Accepted: 04/22/2021] [Indexed: 10/21/2022]
Abstract
Acid-reducing agents (ARAs) are the most commonly used medicines to treat patients with gastric acid-related disorders. ARA administration results in an elevation of intragastric pH and eases symptoms such as acid reflux. However, this effect could also lead to a reduction in the absorption of some co-administered oral medications (i.e. weakly basic drugs) by decreasing their gastric solubility. This in turn can result in a significant reduction of the efficacy of the co-administered oral medications. In order to address this problem, substantial efforts in translational modeling and the development of predictive in-vitro assays to better forecast the effect of ARA on oral absorption are conducted in the pharmaceutical industry. Despite these efforts, it remains challenging to predict the impact of ARAs on co-administered drugs. In this study, we evaluated the utility of Triskelion's Gastro-Intestinal Model (Tiny-TIM) in predicting ARA effect on twelve model drugs whose in-vivo data are available. The Tiny-TIM prediction of the ARA effect matched the observed effect of ARA co-administration in humans for the 12 model compounds. In summary, Tiny-TIM is a very reliable and promising GI model to successfully predict the nature of DDI when ARAs are co-administered with the drug of interest.
Collapse
Affiliation(s)
- Jia Liu
- Small Molecule Pharmaceutical Sciences, Genentech, 1 DNA Way, South San Francisco, CA 94080, USA.
| | - Karthik Nagapudi
- Small Molecule Pharmaceutical Sciences, Genentech, 1 DNA Way, South San Francisco, CA 94080, USA
| | - Michael J Dolton
- Roche Products Australia Pty Ltd, Level 8, 30-34 Hickson Road, Sydney, NSW 2000 Australia
| | - Po-Chang Chiang
- Small Molecule Pharmaceutical Sciences, Genentech, 1 DNA Way, South San Francisco, CA 94080, USA
| |
Collapse
|
6
|
Enhanced anticancer activity of combined treatment of imatinib and dipyridamole in solid Ehrlich carcinoma-bearing mice. Naunyn Schmiedebergs Arch Pharmacol 2020; 393:1113-1129. [PMID: 31950222 DOI: 10.1007/s00210-019-01803-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 12/22/2019] [Indexed: 12/27/2022]
Abstract
The current study was designed to evaluate potential enhancement of the anticancer activity of imatinib mesylate (IM) with dipyridamole (DIP) and to investigate the underlying mechanisms of the combined therapy (IM/DIP) to reduce hepatotoxicity of IM in solid Ehrlich carcinoma (SEC)-bearing mice. SEC was induced in female albino mice as a model for experimentally induced breast cancer. Mice were randomly divided into seven groups (n = 10): SEC vehicle, IM50 (50 mg/kg), IM100 (100 mg/kg), DIP (35 mg/kg), a combination of IM50/DIP and IM100/DIP. On day 28th, mice were sacrificed and blood samples were collected for hematological studies. Biochemical determination of liver markers was evaluated. Glutamic oxaloacetic transaminase (SGOT), glutamic pyruvic transaminase (SGPT) and alkaline phosphatase (ALP) levels were assessed. In addition, MDR-1 gene expression and immunohistochemical staining of BAX and BCL-2 was done. Also, in vitro experiment for determination of IC50 of different treatments and combination index (CI) were assessed in both MCF-7 and HCT-116 cell lines. IM- and/or DIP-treated groups showed a significant reduction in tumor volume, weight, and serum levels of SGOT, SGPT, and AIP compared to vehicle group. In addition, reduction of VEGF, Ki67, and adenosine contents was also reported by treated groups. Also, IM/DIP combination showed lower IC50 than monotherapy. Combination index is less than 1 for IM/DIP combination in both cell lines. DIP as an adjuvant therapy potentiated the cytotoxic effect of IM, ameliorated its hepatic toxicity, and showed synergistic effect with IM in vitro cell lines. Furthermore, the resistance against IM therapy may be overcome by the use of DIP independent on mdr-1 gene expression.
Collapse
|
7
|
Arana MR, Altenberg GA. ATP-binding Cassette Exporters: Structure and Mechanism with a Focus on P-glycoprotein and MRP1. Curr Med Chem 2019; 26:1062-1078. [PMID: 29022498 DOI: 10.2174/0929867324666171012105143] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 08/03/2017] [Accepted: 08/03/2017] [Indexed: 12/11/2022]
Abstract
BACKGROUND Proteins that belong to the ATP-binding cassette superfamily include transporters that mediate the efflux of substrates from cells. Among these exporters, P-glycoprotein and MRP1 are involved in cancer multidrug resistance, protection from endo and xenobiotics, determination of drug pharmacokinetics, and the pathophysiology of a variety of disorders. OBJECTIVE To review the information available on ATP-binding cassette exporters, with a focus on Pglycoprotein, MRP1 and related proteins. We describe tissue localization and function of these transporters in health and disease, and discuss the mechanisms of substrate transport. We also correlate recent structural information with the function of the exporters, and discuss details of their molecular mechanism with a focus on the nucleotide-binding domains. METHODS Evaluation of selected publications on the structure and function of ATP-binding cassette proteins. CONCLUSIONS Conformational changes on the nucleotide-binding domains side of the exporters switch the accessibility of the substrate-binding pocket between the inside and outside, which is coupled to substrate efflux. However, there is no agreement on the magnitude and nature of the changes at the nucleotide- binding domains side that drive the alternate-accessibility. Comparison of the structures of Pglycoprotein and MRP1 helps explain differences in substrate selectivity and the bases for polyspecificity. P-glycoprotein substrates are hydrophobic and/or weak bases, and polyspecificity is explained by a flexible hydrophobic multi-binding site that has a few acidic patches. MRP1 substrates are mostly organic acids, and its polyspecificity is due to a single bipartite binding site that is flexible and displays positive charge.
Collapse
Affiliation(s)
- Maite Rocío Arana
- Instituto de Fisiología Experimental, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, CONICET, Suipacha 570, 2000 Rosario, Argentina
| | - Guillermo Alejandro Altenberg
- Department of Cell Physiology and Molecular Biophysics, and Center for Membrane Protein Research, Texas Tech University Health Sciences Center, Lubbock, Texas 79430-6551, United States
| |
Collapse
|
8
|
Paškevičiūtė M, Petrikaitė V. Overcoming transporter-mediated multidrug resistance in cancer: failures and achievements of the last decades. Drug Deliv Transl Res 2019; 9:379-393. [PMID: 30194528 DOI: 10.1007/s13346-018-0584-7] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Multidrug resistance (MDR) is a complex phenomenon caused by numerous reasons in cancer chemotherapy. It is related to the abnormal tumor metabolism, precisely increased glycolysis and lactic acid production, extracellular acidification, and drug efflux caused by transport proteins. There are few strategies to increase drug delivery into cancer cells. One of them is the inhibition of carbonic anhydrases or certain proton transporters that increase extracellular acidity by proton extrusion from the cells. This prevents weakly basic chemotherapeutic drugs from ionization and increases their penetration through the cancer cell membrane. Another approach is the inhibition of MDR proteins that pump the anticancer agents into the extracellular milieu and decrease their intracellular concentration. Physical methods, such as ultrasound-mediated sonoporation, are being developed, as well. To increase the efficacy of sonoporation, various microbubbles are used. Ultrasound causes microbubble cavitation, i.e., periodical pulsation of the microbubble, and destruction which results in formation of temporary pores in the cellular membrane and increased permeabilization to drug molecules. This review summarizes the main approaches to reverse MDR related to the drug penetration along with its applications in preclinical and clinical studies.
Collapse
Affiliation(s)
- Miglė Paškevičiūtė
- Department of Drug Chemistry, Faculty of Pharmacy, Lithuanian University of Health Sciences, Sukilėlių Ave. 13, LT-50162, Kaunas, Lithuania
| | - Vilma Petrikaitė
- Department of Drug Chemistry, Faculty of Pharmacy, Lithuanian University of Health Sciences, Sukilėlių Ave. 13, LT-50162, Kaunas, Lithuania. .,Institute of Biotechnology, Vilnius University, Saulėtekio Ave. 7, LT-10257, Vilnius, Lithuania.
| |
Collapse
|
9
|
Ion transfer and adsorption behavior of ionizable drugs affected by PAMAM dendrimers at the water|1,2- dichloroethane interface. Electrochim Acta 2016. [DOI: 10.1016/j.electacta.2016.01.122] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
10
|
Milhollen MA, Thomas MP, Narayanan U, Traore T, Riceberg J, Amidon BS, Bence NF, Bolen JB, Brownell J, Dick LR, Loke HK, McDonald AA, Ma J, Manfredi MG, Sells TB, Sintchak MD, Yang X, Xu Q, Koenig EM, Gavin JM, Smith PG. Treatment-emergent mutations in NAEβ confer resistance to the NEDD8-activating enzyme inhibitor MLN4924. Cancer Cell 2012; 21:388-401. [PMID: 22439935 DOI: 10.1016/j.ccr.2012.02.009] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2011] [Revised: 12/12/2011] [Accepted: 02/06/2012] [Indexed: 11/20/2022]
Abstract
MLN4924 is an investigational small-molecule inhibitor of NEDD8-activating enzyme (NAE) in clinical trials for the treatment of cancer. MLN4924 is a mechanism-based inhibitor, with enzyme inhibition occurring through the formation of a tight-binding NEDD8-MLN4924 adduct. In cell and xenograft models of cancer, we identified treatment-emergent heterozygous mutations in the adenosine triphosphate binding pocket and NEDD8-binding cleft of NAEβ as the primary mechanism of resistance to MLN4924. Biochemical analyses of NAEβ mutants revealed slower rates of adduct formation and reduced adduct affinity for the mutant enzymes. A compound with tighter binding properties was able to potently inhibit mutant enzymes in cells. These data provide rationales for patient selection and the development of next-generation NAE inhibitors designed to overcome treatment-emergent NAEβ mutations.
Collapse
|
11
|
Zhou T, Wu W, Zhou S. Engineering oligo(ethylene glycol)-based thermosensitive microgels for drug delivery applications. POLYMER 2010. [DOI: 10.1016/j.polymer.2010.06.030] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
12
|
Karanikolopoulos N, Zamurovic M, Pitsikalis M, Hadjichristidis N. Poly(dl-lactide)-b-poly(N,N-dimethylamino-2-ethyl methacrylate): Synthesis, Characterization, Micellization Behavior in Aqueous Solutions, and Encapsulation of the Hydrophobic Drug Dipyridamole. Biomacromolecules 2009; 11:430-8. [DOI: 10.1021/bm901151g] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Nikos Karanikolopoulos
- Industrial Chemistry Laboratory, Department of Chemistry, University of Athens, Panepistimiopolis Zografou, 15771 Athens, Greece
| | - Miljana Zamurovic
- Industrial Chemistry Laboratory, Department of Chemistry, University of Athens, Panepistimiopolis Zografou, 15771 Athens, Greece
| | - Marinos Pitsikalis
- Industrial Chemistry Laboratory, Department of Chemistry, University of Athens, Panepistimiopolis Zografou, 15771 Athens, Greece
| | - Nikos Hadjichristidis
- Industrial Chemistry Laboratory, Department of Chemistry, University of Athens, Panepistimiopolis Zografou, 15771 Athens, Greece
| |
Collapse
|
13
|
Lehotzky A, Tőkési N, Gonzalez-Alvarez I, Merino V, Bermejo M, Orosz F, Lau P, Kovacs G, Ovádi J. Progress in the development of early diagnosis and a drug with unique pharmacology to improve cancer therapy. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2008; 366:3599-3617. [PMID: 18644768 PMCID: PMC2696110 DOI: 10.1098/rsta.2008.0106] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Cancer continues to be one of the major health and socio-economic problems worldwide, despite considerable efforts to improve its early diagnosis and treatment. The identification of new constituents as biomarkers for early diagnosis of neoplastic cells and the discovery of new type of drugs with their mechanistic actions are crucial to improve cancer therapy. New drugs have entered the market, thanks to industrial and legislative efforts ensuring continuity of pharmaceutical development. New targets have been identified, but cancer therapy and the anti-cancer drug market still partly depend on anti-mitotic agents. The objective of this paper is to show the effects of KAR-2, a potent anti-mitotic compound, and TPPP/p25, a new unstructured protein, on the structural and functional characteristics of the microtubule system. Understanding the actions of these two potential effectors on the microtubule system could be the clue for early diagnosis and improvement of cancer therapy.
Collapse
Affiliation(s)
- A. Lehotzky
- Institute of Enzymology, Biological Research Centre, Hungarian Academy of SciencesKarolina út 29, 1113 Budapest, Hungary
| | - N. Tőkési
- Institute of Enzymology, Biological Research Centre, Hungarian Academy of SciencesKarolina út 29, 1113 Budapest, Hungary
| | - I. Gonzalez-Alvarez
- Department of Pharmaceutics and Pharmaceutical Technology, University of Valencia46010 Valencia, Spain
| | - V. Merino
- Department of Pharmaceutics and Pharmaceutical Technology, University of Valencia46010 Valencia, Spain
| | - M. Bermejo
- Department of Pharmaceutics and Pharmaceutical Technology, University of Valencia46010 Valencia, Spain
| | - F. Orosz
- Institute of Enzymology, Biological Research Centre, Hungarian Academy of SciencesKarolina út 29, 1113 Budapest, Hungary
| | - P. Lau
- Section of Developmental Genetics, National Institute of Neurological Disorders and Stroke, National Institutes of HealthBethesda, MD 20892, USA
| | - G.G. Kovacs
- Institute of Neurology, Medical University of Vienna1097 Vienna, Austria
| | - J. Ovádi
- Institute of Enzymology, Biological Research Centre, Hungarian Academy of SciencesKarolina út 29, 1113 Budapest, Hungary
| |
Collapse
|
14
|
Leamon CP, Reddy JA, Vlahov IR, Westrick E, Dawson A, Dorton R, Vetzel M, Santhapuram HK, Wang Y. Preclinical antitumor activity of a novel folate-targeted dual drug conjugate. Mol Pharm 2007; 4:659-67. [PMID: 17874843 DOI: 10.1021/mp070049c] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We have designed a new type of tumor-targeted agent by tethering two different drug molecules, with distinct biological mechanisms of action, to the same ligand. This compound, named EC0225, represents the "first in class" multidrug, folate receptor (FR)-targeted agent to be disclosed. It was constructed with a single folate molecule, extended by a hydrophilic peptide-based spacer, which was in turn attached to mitomycin and Vinca alkaloid units via two separate disulfide-containing linkers. EC0225 produced potent, dose-responsive activity in vitro, and curative activity was observed against FR-positive syngeneic and xenograft tumors following the administration of well-tolerated dosing regimens. Multiple complete responses and cures were also noted when EC0225 was used to treat mice initially bearing tumors as large as 750 mm (3) in volume. Overall, EC0225's impressive preclinical activity allowed for its selection as a development candidate and for the start of Phase 1 clinical trials, which began in March of 2007, for the treatment of advanced malignancies.
Collapse
|
15
|
Bains OS, Kennedy CJ. Alterations in respiration rate of isolated rainbow trout hepatocytes exposed to the P-glycoprotein substrate rhodamine 123. Toxicology 2005; 214:87-98. [PMID: 16026915 DOI: 10.1016/j.tox.2005.06.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2004] [Revised: 06/02/2005] [Accepted: 06/04/2005] [Indexed: 11/25/2022]
Abstract
Reducing intracellular xenobiotic concentration is an important defence strategy used by cells challenged with foreign chemicals. One mechanism used to achieve this goal is via the use of P-glycoproteins (P-gps), ATP-dependent transporters that mediate the removal of hydrophobic compounds from cells. The energetic costs of this mechanism are unknown, therefore, the activity and respiratory costs associated with the P-gp-mediated efflux of rhodamine 123 (R123) was measured in isolated rainbow trout hepatocytes. The accumulation of R123 was rapid and concentration-dependent. Initial accumulation rates were 1.79+/-0.41, 7.29+/-1.06 and 15.30+/-1.74ngR123/min/10(6)cells when exposed to 1, 5 and 10 microM R123, respectively. Efflux was measured in cells 'pre-loaded' with R123 at each concentration, resulting in initial efflux rates of 0.77+/-0.12, 2.02+/-0.35 and 3.51+/-0.84ngR123/min/10(6)cells, respectively. The baseline oxygen consumption rate of hepatocytes was 33.21+/-1.09 ng O2/min/10(6)cells. Respiration rates were significantly higher in cells exposed to 5 and 10 microM R123 (39.08+/-0.80 and 41.72+/-0.61ng O2/min/10(6)cells), representing increases over basal rates of 18.5 and 25.7%, respectively. Measurements of isolated mitochondrial respiration established that changes in hepatocyte oxygen consumption were not through the direct effects of R123 on mitochondria. The P-gp inhibitor, XR9576 significantly inhibited R123 efflux from cells with a concomitant return of respiration rates to baseline values. This study demonstrates that increased P-gp transport of xenobiotics can significantly raise cellular respiration rates and may result in higher energy costs for organisms living in P-gp-substrate contaminated environments.
Collapse
Affiliation(s)
- Onkar S Bains
- Department of Biological Sciences, Simon Fraser University, 8888 University Drive, Burnaby, BC, Canada V5A 1S6
| | | |
Collapse
|
16
|
Tang Y, Liu SY, Armes SP, Billingham NC. Solubilization and controlled release of a hydrophobic drug using novel micelle-forming ABC triblock copolymers. Biomacromolecules 2004; 4:1636-45. [PMID: 14606890 DOI: 10.1021/bm030026t] [Citation(s) in RCA: 152] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Amphiphilic ABC triblock copolymers composed of monomethoxy-capped poly(ethylene glycol) (MPEG), poly(2-(dimethylamino)ethyl methacrylate) (DMA), and poly(2-(diethylamino)ethyl methacrylate) (DEA) have been synthesized by atom transfer radical polymerization (ATRP). These copolymers dissolve molecularly in acidic aqueous media at room temperature due to protonation of the tertiary amine groups on the DMA and DEA residues. On adjusting the pH with base, micellization occurred at pH 8, with the water-insoluble, deprotonated DEA block forming the hydrophobic cores and the MPEG and DMA blocks forming the hydrophilic micellar coronas and inner shells, respectively. This pH-induced micellization has been exploited to develop a solvent-free protocol for drug loading. A model hydrophobic drug, dipyridamole (DIP), which dissolves in acid but is insoluble above pH 5.8, was incorporated into the micelles by increasing the pH of an aqueous drug/copolymer mixture to 9. Both the empty and the drug-loaded micelles were characterized by dynamic light scattering and fluorescence studies. The interaction of both pyrene and DIP with the MPEG-DMA-DEA micelles was studied by fluorescence; both compounds had relatively high partition coefficients into the micelles, 4.5 x 10(5) and 1.5 x 10(4), respectively. Intensity-average micelle diameters ranged from 20 to 90 nm, depending on the polymer composition and concentration. Shorter MPEG blocks (Mn = 2000) produced larger micelles than longer MPEG blocks (Mn = 5000) due to the shift in the hydrophilic-hydrophobic balance of the copolymer. Transmission electron microscopy studies of the drug-loaded micelles indicated spherical morphologies and reasonably uniform particle size distributions, which is in marked contrast to the needlelike morphology observed for pure DIP in the absence of the copolymer. Experiments on controlled release demonstrated that DIP-loaded MPEG-DMA-DEA micelles act as a drug carrier, giving slow release to the surrounding solution over a period of days. Rapid release can be triggered by reducing the pH to reverse the micellization.
Collapse
Affiliation(s)
- Yiqing Tang
- Department of Chemistry, University of Sussex, Falmer, Brighton BN1 9QJ, United Kingdom
| | | | | | | |
Collapse
|
17
|
Meesungnoen J, Jay-Gerin JP, Mankhetkorn S. Relation between MDR1 mRNA levels, resistance factor, and the efficiency of P-glycoprotein-mediated efflux of pirarubicin in multidrug-resistant K562 sublines. Can J Physiol Pharmacol 2002; 80:1054-63. [PMID: 12489924 DOI: 10.1139/y02-132] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In this work, we sought to investigate the relation existing between MDR1 mRNA levels, the resistance factor (RF), and the efficiency of efflux of pirarubicin (THP) mediated by P-glycoprotein (P-gp) in multidrug-resistant (MDR) K562 sublines. The MDR K562 sublines were selected from K562/adr cells by exposure to different adriamycin concentrations: 300 nM (K562/300), 1,000 nM (K562/1,000), and 10,000 nM (K562/10,000), yielding RF values of 23.2, 26.5, and 39.6, respectively. The analysis of the P-gp encoding MDR1 gene overexpression by reverse transcriptase - polymerase chain reaction provided evidence of increased MDR1 mRNA levels when the adriamycin concentration used for the MDR cell selection increased. We used spectrofluorometric methods to determine the kinetics of the uptake and P-gp-mediated efflux of THP in the different selected MDR K562 sublines. Our data showed that (i) the maximal rate of P-gp-mediated efflux of THP, Vmax, increased with increasing RF; (ii) the observed Michaelis constant, Km, had the same value for all selected sublines, thus leading to an overall increase in the ratio Vmax/Km (5.1 x 10(-3), 6.2 x 10(-3), 6.8 x 10(-3), and 9.3 x 10(-3) s(-1) for K562/adr, K562/300, K562/1,000, and K562/10,000 cells, respectively), and (iii) the determination of the Hill coefficient (nH) gave values close to 2, which suggested a positive cooperative transport of THP with the expelling of two molecules of THP per turnover of P-gp. This study demonstrated that, in the K562/adr sublines used in our experiments, P-gp played a major role in conferring the MDR phenotype. Moreover, under our experimental conditions, intracellular acidic organelles were shown to contribute to decreased drug-target interaction and, thereby, decreased cytotoxicity. The variation of the concentrations of THP accumulated in the acidic organelles as a function of the total TFP concentration added to the cells was the same, within the limits of experimental errors, whatever the degree of resistance of the studied MDR K562 sublines. Finally, this study suggested that, in the selected MDR K562 sublines, the K+/H+ antiporter exchanger could be activated by the pirarubicin transport, leading to a probable acidification of intracellular pH. The P-gp-mediated efflux of THP and an accumulation of THP in acidic organelles confer an advantage for MDR cells in surviving prolonged exposure to cytotoxic agents and giving rise to high degrees of resistance.
Collapse
Affiliation(s)
- Jintana Meesungnoen
- Laboratory of Physical Chemistry, Molecular and Cellular Biology, Faculty of Science, Burapha University, Bangsaen, Chonburi 20131, Thailand
| | | | | |
Collapse
|
18
|
Kusuhara H, Sugiyama Y. Efflux transport systems for drugs at the blood-brain barrier and blood-cerebrospinal fluid barrier (Part 1). Drug Discov Today 2001; 6:150-156. [PMID: 11165188 DOI: 10.1016/s1359-6446(00)01632-9] [Citation(s) in RCA: 108] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Penetration through the blood-brain barrier (BBB) and blood-cerebrospinal fluid barrier (BCSFB) is necessary if a drug is to achieve the required concentration for a desired pharmacological effect. Efflux transport systems at the BBB and BCSFB provide a protective barrier function by removing drugs from the brain or cerebrospinal fluid and transferring them to the systemic circulation, respectively; several transporters at the BBB and BCSFB have been identified. Efflux transport should be taken into consideration during drug development to improve brain penetration and to avoid drug-drug interactions involving these transporters and subsequent side effects.
Collapse
Affiliation(s)
- H Kusuhara
- Department of Biopharmaceutics, Graduate School of Pharmaceutical Sciences, University of Tokyo, Tokyo, Japan
| | | |
Collapse
|
19
|
Knox PP, Churbanova IY, Lukashev EP, Zakharova NI, Rubin AB, Borissevitc GP. Dipyridamole and its derivatives modify the kinetics of the electron transport in reaction centers from Rhodobacter sphaeroides. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2000; 56:68-77. [PMID: 11073318 DOI: 10.1016/s1011-1344(00)00062-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A well known vasodilator dipyridamole (DIP), 2,6-bis(diethanolamino)-4,8-dipiperidinopyrimido[5,4-d]pyrim idine, and its derivatives have recently been shown as potential co-activators (modulators) in the phenomenon of multidrug resistance (MDR) in cancer therapy. They inhibit the specific function of a transmembrane P-glycoprotein responsible for the ex-flux of anti-cancer drugs from tumor cells. To clarify molecular mechanisms of the anti-MDR activity of DIP and its two derivatives, RA25 and RA47, we have studied their effects on electron transport in reaction centers (RC) from purple photosynthetic bacteria Rb. sphaeroides, using RC as a model system. Increasing concentrations of DIP and RA47 progressively accelerate the back electron transfer from the primary quinone acceptor QA to the bacteriochlorophyll dimer Bchl2 (Bchl2+ -QA- recombination). In the absence of o-phenantroline, when both quinone acceptors QA and QB are involved in the electron transport, RA47 is more effective than DIP. DIP stabilizes the electron on the secondary quinone acceptor QB, the effect manifested as the retardation of Bchl2+ -QB- recombination. Effects of RA25 are negligible in all cases. The drugs are proposed to change the electron transport affecting the RC structural dynamics and the stabilization of the electron on quinone acceptors through modification of H-bonds in the system.
Collapse
Affiliation(s)
- P P Knox
- Biophysics Department, Biology Faculty, M.V. Lomonosov State University, Moscow, Russia
| | | | | | | | | | | |
Collapse
|
20
|
Powles R, Sirohi B, Kulkarni S, Bhagwati N, Saso R, Raje N, Horton C, Singhal S, Mehta J, Treleaven J. Acute lymphoblastic leukaemia-type intensive chemotherapy to eliminate minimal residual disease after high-dose melphalan and autologous transplantation in multiple myeloma - a phase I/II feasibility and tolerance study of 17 patients. Bone Marrow Transplant 2000; 25:949-56. [PMID: 10800062 DOI: 10.1038/sj.bmt.1702379] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Aiming to target the minimal residual disease in patients with multiple myeloma, a phase I/II single centre study was undertaken for feasibility and tolerance of intensive acute lymphoblastic leukaemia consolidation chemotherapy (ALL-IC) as part of a strategy for post-transplant consolidation targeted at pre-B cells. Seventeen newly diagnosed patients with myeloma (median age 55 years; 30-65) were initially treated with courses of infused cyclophosphamide, vincristine, adriamycin and methylprednisolone (C-VAMP) followed by melphalan 200 mg/m2(HDM) and peripheral blood stem cell rescue (PBSC). Forty-seven percent were in CR and the rest in PR after HDM. ALL-IC consisted of vincristine, daunorubicin, etoposide, cytarabine, 6-thioguanine and prednisolone given over 5 days. All patients became neutropenic (<0.5 x 109/l) at a median of 10 days (4-18) and one of the 17 patients (5.8%) died 15 days post ALL-IC of sepsis. A further four have died of relapse with an overall survival (OS) of 67% at 4 years. Two of nine patients in PR at the time of ALL-IC achieved CR. Matched-pair analysis of 34 control patients shows no difference for OS and event-free survival between ALL-IC and controls. We conclude that ALL-IC given to myeloma patients after HDM/PBSC is as safe as when used in ALL and warrants further assessment in randomised trials for myeloma.
Collapse
Affiliation(s)
- R Powles
- Leukaemia and Myeloma Units, Royal Marsden NHS Trust and Institute of Cancer Research, Sutton, UK
| | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Sirohi B, Powles R, Treleaven J, Mainwaring P, Kulkarni S, Pandha H, Bhagwati N, Horton C, Singhal S, Mehta J. The role of autologous transplantation in patients with multiple myeloma aged 65 years and over. Bone Marrow Transplant 2000; 25:533-9. [PMID: 10713631 DOI: 10.1038/sj.bmt.1702188] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Autologous stem cell transplantation after high-dose melphalan for the treatment with multiple myeloma has resulted in prolonged progression-free survival and overall survival in patients under 65 years. We have examined the role of autologous transplantation in 17 patients with multiple myeloma over 65 years at our centre using a matched pair analysis with younger patients. The median age of this cohort of patients over 65 years was 67 years (65-74) and their outcome and transplant-related morbidity was compared with 17 younger pair mates with a median age of 55 years (31-64). Sixteen patients received high-dose melphalan, and one received busulphan with autologous stem cell rescue. The high-dose therapy was well tolerated in both elderly patients and the matched pairs, with comparable time to recover neutrophils and platelets. Treatment-related mortality also did not differ significantly in both the groups. Median overall survival of the elderly patients was 3.59 years similar to 3.01 years of the pair mates (P = 0.92). Autologous stem cell transplantation after high-dose melphalan conditioning was equally well tolerated in groups of patients above and below 65 years. There was no difference in relapse rate, OS and myelotoxicity in both the groups. These findings suggest that advanced age should not be an exclusion criterion from autologous transplant programmes. Bone Marrow Transplantation (2000) 25, 533-539.
Collapse
Affiliation(s)
- B Sirohi
- Leukaemia and Myeloma Units, Royal Marsden NHS Trust, Sutton, Surrey, UK
| | | | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Eytan GD, Kuchel PW. Mechanism of action of P-glycoprotein in relation to passive membrane permeation. INTERNATIONAL REVIEW OF CYTOLOGY 1999; 190:175-250. [PMID: 10331240 DOI: 10.1016/s0074-7696(08)62148-8] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
This review presents a survey of studies of the movement of chemotherapeutic drugs into cells, their extrusion from multidrug-resistant (MDR) cells overexpressing P-glycoprotein (Pgp), and the mode of sensitization of MDR cells to anticancer drugs by Pgp modulators. The consistent features of the kinetics from studies of the operation of Pgp in cells were combined in a computer model that enables the simulation of experimental scenarios. MDR-type drugs are hydrophobic and positively charged and as such bind readily to negatively charged phospholipid head groups of the membrane. Transmembrane movement of MDR-type drugs, such as doxorubicin, occurs by a flip-flop mechanism with a lifetime of about 1 min rather than by diffusion down a gradient present in the lipid core. A long residence time of a drug in the membrane leaflet increases the probability that P-glycoprotein will remove it from the cell. In a manner similar to ion-transporting ATPases, such as Na+,K(+)-ATPase, Pgp transports close to one drug molecule per ATP molecule hydrolyzed. Computer simulation of cellular pharmacokinetics, based on partial reactions measured in vitro, show that the efficiency of Pgp, in conferring MDR on cells, depends on the pumping capacity of Pgp and its affinity toward the specific drug, the transmembrane movement rate of the drug, the affinity of the drug toward its pharmacological cellular target, and the affinity of the drug toward intracellular trapping sites. Pgp activities present in MDR cells allow for the efficient removal of drugs, whether directly from the cytoplasm or from the inner leaflet of the plasma membrane. A prerequisite for a successful modulator, capable of overcoming cellular Pgp, is the rapid passive transbilayer movement, allowing it to reenter the cell immediately and thus successfully occupy the Pgp active site(s).
Collapse
Affiliation(s)
- G D Eytan
- Department of Biology, Technion-Israel Institute of Technology, Haifa, Israel
| | | |
Collapse
|
23
|
Pereira E, Tarasiuk J, Garnier-Suillerot A. Kinetic analysis in living cells of the inhibition of the P-glycoprotein-mediated efflux of anthracyclines by vinca alkaloids. Chem Biol Interact 1998; 114:61-76. [PMID: 9744556 DOI: 10.1016/s0009-2797(98)00036-2] [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] [Indexed: 11/20/2022]
Abstract
Cells that overexpress the mdr 1 gene have decreased steady-state accumulation and increased efflux of many anticancer drugs including anthracyclines and vinca alkaloids. The mechanism(s) of P-glycoprotein-mediated efflux of drugs is (are) still poorly understood. In an attempt to identify mechanism(s) by which multidrug resistance can be circumvented, the cellular accumulation has been examined of pirarubicin, doxorubicin and idarubicin alone and in conjunction with four vinca alkaloid derivatives--vinblastine, navelbine, vindesine and vincristine. The present study was performed using a spectrofluorometric method with which it is possible to follow continuously the uptake and release of fluorescent molecules by living cells, as the incubation of the cells with the drug proceeds. Erythroleukemia K562 cell lines were used. It has been shown that the P-glycoprotein-mediated efflux of these three anthracyclines can be inhibited by vinca alkaloids derivatives. At pH 7.2, 50% of the P-glycoprotein-mediated efflux of daunorubicin and idarubicin was inhibited by about 40 +/- 10 microM vinblastine and that of pirarubicin by 10 +/- 2 microM vinblastine. The vinblastine concentration required to inhibit 50% of the active efflux of these anthracyclines did not depend on the anthracycline concentrations used, indicating that the inhibition was non competitive. The ability of navelbine, vincristine and vindesine to inhibit the active efflux of pirarubicin was also checked; 15 +/- 3 microM navelbine are required to inhibit 50% of the active efflux but at concentrations lower than 100 microM, neither vincristine nor vindesine were able to inhibit this efflux, indicating that the vinca alkaloids compounds which are the most efficient are the most lipophilic. For the four vinca alkaloids, the concentration required to inhibit 50% of the efflux was lower as the pH was higher. A detailed kinetics analysis of the P-glycoprotein-mediated efflux of pirarubicin in the presence of vinblastine indicates a non competitive inhibition with K(I) = 12 +/- 2 microM.
Collapse
Affiliation(s)
- E Pereira
- Laboratoire de Physicochimie Biomoléculaire et Cellulaire (UPRES-A 7033), Université Paris-Nord, Bobigny, France
| | | | | |
Collapse
|
24
|
Yang JM, Sullivan GF, Hait WN. Regulation of the function of P-glycoprotein by epidermal growth factor through phospholipase C. Biochem Pharmacol 1997; 53:1597-604. [PMID: 9264311 DOI: 10.1016/s0006-2952(97)82451-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Many multidrug-resistant (MDR) cell lines overexpress the epidermal growth factor receptor (EGFR) as well as P-glycoprotein (P-gp). However, the role of the increased EGFR in P-gp-mediated drug resistance remains unclear. Since recent studies suggest that activation of phospholipase C (PLC) could increase the phosphorylation of P-gp, and activation of the EGFR would also activate PLC, we investigated whether the effect of epidermal growth factor (EGF) on the phosphorylation of P-gp was mediated through PLC. Treatment of the human MDR breast cancer cell line, MCF-7/AdrR, with EGF increased the phosphorylation of P-gp by 20-50%. The increased phosphorylation of P-gp was accompanied by stimulation of PLC activity, as measured by the production of inositol, 1,4,5-trisphosphate and diacylglycerol, products of phosphatidylinositol-4,5-bisphosphate hydrolysis. Treatment of MDR cells with EGF also had detectable effects on P-gp function. For example, following incubation of MCF-7/AdrR cells with ECF, we observed a consistent decrease in total vinblastine (VBL) accumulation. Kinetic analysis revealed this change to be due to an increase in membrane efflux. The latter was measured by the initial uptake velocity, which was inhibited by EGF. VBL uptake measured at 0-320 sec was inhibited by 20-40%, which was associated with a similar increase in VBL efflux. EGF had no effect on drug accumulation, uptake, or efflux in sensitive MCF-7 cells. These data indicate that EGF can modulate the phosphorylation and function of P-gp, and suggest that this effect may be initiated by the activation of PLC.
Collapse
Affiliation(s)
- J M Yang
- Department of Medicine, University of Medicine and Dentistry of New Jersey/Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA
| | | | | |
Collapse
|
25
|
Hepatobiliary elimination of cationic drugs: the role of P-glycoproteins and other ATP-dependent transporters. Adv Drug Deliv Rev 1997. [DOI: 10.1016/s0169-409x(97)00498-5] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
|
26
|
Wadkins RM, Roepe PD. Biophysical aspects of P-glycoprotein-mediated multidrug resistance. INTERNATIONAL REVIEW OF CYTOLOGY 1997; 171:121-65. [PMID: 9066127 DOI: 10.1016/s0074-7696(08)62587-5] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
In the 45 years since Burchenal's observation of chemotherapeutic drug resistance in tumor cells, many investigators have studied the molecular basis of tumor drug resistance and the phenomenon of tumor multidrug resistance (tumor MDR). Examples of MDR in microorganisms have also become topics of intensive study (e.g., Plasmodium falciparum MDR and various types of bacterial MDR) and these emerging fields have, in some cases, borrowed language, techniques, and theories from the tumor MDR field. Serendipitously, the cloning of MDR genes overexpressed in MDR tumor cells has led to elucidation of a large family of membrane proteins [the ATP-binding cassette (ABC) proteins], an important subset of which confer drug resistance in many different cells and microorganisms. In trying to decipher how ABC proteins confer various forms of drug resistance, studies on the structure and function of both murine and human MDR1 protein (also called P-glycoprotein or P-gp) have often led the way. Although various theories of P-gp function have become popular, there is still no precise molecular-level description for how P-gp overexpression lowers intracellular accumulation of chemotherapeutic drugs. In recent years, controversy has developed over whether the protein protects cells by translocating drugs directly (as some type of drug pump) or indirectly (through modulating biophysical parameters of the cell). In this ongoing debate over P-gp function, detailed consideration of biophysical issues is critical but has often been neglected in considering cell biological and pharmacological issues. In particular, P-gp overexpression also changes plasma membrane electrical potential (delta psi zero) and intracellular pH (pHi), and these changes will greatly affect the cellular flux of a large number of compounds to which P-gp overexpression confers resistance. In this chapter, we highlight these biophysical issues and describe how delta psi zero and pHi may in fact be responsible for many MDR-related phenomena that have often been hypothesized to be due to direct drug translocation (e.g., drug pumping) by P-gp.
Collapse
Affiliation(s)
- R M Wadkins
- Raymond & Beverly Sackler Foundation Laboratory, Memorial Sloan-Kettering Cancer Center, New York, New York, USA
| | | |
Collapse
|
27
|
Hwang M, Ahn CH, Pine PS, Yin JJ, Hrycyna CA, Licht T, Aszalos A. Effect of combination of suboptimal concentrations of P-glycoprotein blockers on the proliferation of MDR1 gene expressing cells. Int J Cancer 1996; 65:389-97. [PMID: 8575863 DOI: 10.1002/(sici)1097-0215(19960126)65:3<389::aid-ijc19>3.0.co;2-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Pharmacologically active in vivo doses of P-glycoprotein (Pgp) blockers, specifically verapamil, Cremophor EL and PSC833 cause toxicity in addition to that from the concomitantly used cancer chemotherapeutic drugs. It was shown before that these blockers cause different types of toxicities in vivo. We found that these 3 chemically distinct Pgp blockers exert different biophysical effects on the membranes of L1210 MDR cells. They also affect the general metabolism of these cells differently, but all block affinity labeling of Pgp. We could also show that the combination of suboptimal doses of these blockers can restore the uptake of the Pgp substrate rhodamine 123 into L1210MDR, 3T3MDR and KB-VI cells and can reduce the survival rate of these cells when treated in combination with daunorubicin. Our results suggest that the combination of suboptimal doses of these Pgp blockers may be advantageous in clinical practice.
Collapse
Affiliation(s)
- M Hwang
- Center for Drug Evaluation and Research, Food and Drug Administration, Washington, DC 20204, USA
| | | | | | | | | | | | | |
Collapse
|
28
|
Borissevitch IE, Borges CP, Yushmanov VE, Tabak M. Localization of dipyridamole molecules in ionic micelles: effect of micelle and drug charges. BIOCHIMICA ET BIOPHYSICA ACTA 1995; 1238:57-62. [PMID: 7654751 DOI: 10.1016/0005-2736(95)00112-g] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The localization of the coronary vasodilator dipyridamole (DIP) in cationic cetyltrimethylammonium chloride (CTAC), anionic sodium dodecylsulfate (SDS) and zwitterionic N-hexadecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate and lysophosphatidylcholine (HPS and LPC) micelles was investigated using fluorescence quenching by quenchers with known localization in the micelle (TEMPO and 5-doxyl and 12-doxyl stearic acids). The use of fluorescence quenching jointly with fluorescence and 1H-NMR spectral measurements shows that DIP molecules in both protonated and nonprotonated forms are localized in micelles near the region which separates their polar and nonpolar parts, the polarizable heteroaromatic cycle of DIP being close to the polar part and the nonpolar substituents penetrating the hydrophobic interior of the micelle. The electrostatic interaction between the protonated DIP molecules and micelle charges either moves DIP into the micelle interior (for cationic and zwitterionic micelles) or draws it closer to the micelle surface (for anionic ones). Our results could be relevant to the mechanism of DIP action since many data indicate the interaction of the drug with cell membranes. The ability of DIP to localize near the membrane surface with the substituents immersed into a hydrophobic moiety could be essential for the drug interaction with P-glycoprotein, which is responsible for mediation of the effects of several antitumour drugs.
Collapse
Affiliation(s)
- I E Borissevitch
- Instituto de Química de São Carlos, Universidade de São Paulo, Brazil
| | | | | | | |
Collapse
|
29
|
Nielsen D, Maare C, Skovsgaard T. Influx of daunorubicin in multidrug resistant Ehrlich ascites tumour cells: correlation to expression of P-glycoprotein and efflux. Influence of verapamil. Biochem Pharmacol 1995; 50:443-50. [PMID: 7646548 DOI: 10.1016/0006-2952(95)00172-v] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Classic multidrug resistance is characterized by a decrease in the intracellular concentration of drugs in resistant cells as compared to sensitive cells. This is correlated with the presence of P-glycoprotein in the membrane. P-glycoprotein is responsible for an active efflux of drug. In this study we investigated the correlation between P-glycoprotein and influx of daunorubicin. Four Ehrlich ascites tumour cell lines selected in vivo for resistance to daunorubicin were investigated. The sublines EHR2/0.1, EHR2/0.2, passage no. 12 of EHR2/0.8, EHR2/0.4, and passage no. 72 of EHR2/0.8 were 6-, 6-, 5-, 33-, and 35-fold resistant to daunorubicin, respectively. All sublines overexpressed P-glycoprotein as determined with Western blot. Influx was measured over 40 sec. In glucose-enriched medium influx was significantly decreased in all but one of the resistant sublines. A correlation between P-glycoprotein, degrees of resistance, and influx was demonstrated in four sublines. Comparing influx experiments with efflux experiments (Nielsen et al., Biochem Pharmacol 1994, 47, 2125-2135) we found a linear relationship between influx and efflux in the resistant sublines (r = 0.97). Verapamil (5.5 microM, 11.0 microM) increased influx significantly in all resistant sublines, whereas the drug had no effect on sensitive cells. Verapamil (3.3 microM) increased influx in the EHR2/0.8 (passage no. 72) subline to the level of sensitive cells. Comparing this result with efflux experiments, verapamil was found to increase influx preferentially. Depletion of energy (medium without glucose including Na(+)-azide) increased influx in all resistant sublines. In EHR2/0.4 and EHR2/0.8 (passage no. 72) the influx, however, was still significantly decreased after depletion of energy. In these cells further addition of verapamil increased influx to the level of EHR2. These data were consistent with the hypothesis that P-glycoprotein effluxes drug directly from the plasma membrane.
Collapse
Affiliation(s)
- D Nielsen
- Department of Oncology R, Herlev Hospital, University of Copenhagen, Denmark
| | | | | |
Collapse
|
30
|
Dordal MS, Ho AC, Jackson-Stone M, Fu YF, Goolsby CL, Winter JN. Flow cytometric assessment of the cellular pharmacokinetics of fluorescent drugs. CYTOMETRY 1995; 20:307-14. [PMID: 7587718 DOI: 10.1002/cyto.990200406] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Development of multidrug resistance (MDR) in cancer cells decrease net doxorubicin uptake as a result of either increased efflux, or decreased intracellular sequestration, or decreased membrane permeability. Kinetic parameters of drug uptake can distinguish among these forms of altered transport. Cellular uptake of fluorescent drugs was monitored by a flow cytometric assay using a rapid-injection system and analyzed with a three-compartment model in which rapid diffusion from extracellular fluid into the cell was followed by uptake into a nonexchangeable pool. In agreement with our recent studies of 14C-doxorubicin distribution (Dordal et al.: J Pharmacol Exp Ther 271:1286-1290, 1994), sequestration of doxorubicin was decreased 2.7-fold in P-glycoprotein-expressing SU-4R lymphoma cells compared to drug-sensitive SU-4 cells (14.0 +/- 4.8 vs. 5.0 +/- 0.9 nl s-1) without a change in membrane permeability or evidence of active efflux. In contrast, sequestration of the highly fluorescent dye rhodamine 123 was decreased 20-fold (17.1 +/- 8.3 vs. 0.9 +/- 0.8 nl s-1). Resistant cells were significantly less permeable to rhodamine than sensitive cells (3.8 +/- 1.2 vs. 10.2 +/- 2.6 x 10(5) cm2 s-1), and rhodamine efflux was increased by 24%. Thus, SU-4R cells exhibit multiple alterations that cause decreased intracellular drug concentrations, of which decreased sequestration is quantitatively the most significant.
Collapse
Affiliation(s)
- M S Dordal
- Clinical Pharmacology Center, Robert H. Lurie Cancer Center, Northwestern Memorial Hospital, Chicago, Illinois, USA
| | | | | | | | | | | |
Collapse
|
31
|
Oude Elferink RP, Meijer DK, Kuipers F, Jansen PL, Groen AK, Groothuis GM. Hepatobiliary secretion of organic compounds; molecular mechanisms of membrane transport. BIOCHIMICA ET BIOPHYSICA ACTA 1995; 1241:215-68. [PMID: 7640297 DOI: 10.1016/0304-4157(95)00006-d] [Citation(s) in RCA: 249] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- R P Oude Elferink
- Department of Gastrointestinal and Liver Diseases, Academic Medical Center, AZ Amsterdam, The Netherlands
| | | | | | | | | | | |
Collapse
|
32
|
Licht T, Pastan I, Gottesman M, Herrmann F. P-glycoprotein-mediated multidrug resistance in normal and neoplastic hematopoietic cells. Ann Hematol 1994; 69:159-71. [PMID: 7948302 DOI: 10.1007/bf02215949] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The multidrug transporter, P-glycoprotein (P-gp), is expressed by CD34-positive bone marrow cells, which include hematopoietic stem cells, and in other cells in the bone marrow and peripheral blood, including some lymphoid cells. Multidrug resistance mediated by P-gp appears to be a major impediment to successful treatment of acute myeloid leukemias and multiple myelomas. However, the impact of P-gp expression on prognosis has to be confirmed in several other hematopoietic neoplasms. The role of P-gp in normal and malignant hematopoiesis and clinical attempts to circumvent multidrug resistance in hematopoietic malignancies are reviewed. The recent transduction of the MDR1 gene into murine hematopoietic cells, which protects them from toxic effects of chemotherapy, suggests that MDR1 gene therapy may help prevent myelosuppression following chemotherapy.
Collapse
Affiliation(s)
- T Licht
- National Cancer Institute, NIH, Laboratory of Molecular Biology, Bethesda, MD
| | | | | | | |
Collapse
|
33
|
Altenberg GA, Vanoye CG, Horton JK, Reuss L. Unidirectional fluxes of rhodamine 123 in multidrug-resistant cells: evidence against direct drug extrusion from the plasma membrane. Proc Natl Acad Sci U S A 1994; 91:4654-7. [PMID: 7910961 PMCID: PMC43846 DOI: 10.1073/pnas.91.11.4654] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
P-glycoprotein (Pgp), a plasma membrane protein overexpressed in multidrug-resistant tumor cells, is an ATPase thought to actively export cytotoxic drugs. It has been proposed that Pgp transports drugs directly from the lipid bilayer to the external medium ("vacuum cleaner" hypothesis). A possible mechanism for this model is that the Pgp is a flippase--i.e., it catalyzes the translocation of hydrophobic substrates from the inner to the outer leaflet of the cell membrane. Two immediate predictions of the vacuum cleaner and flippase hypotheses are that the apparent unidirectional influx of substrate should be less in Pgp-expressing than in Pgp-lacking cells and that this difference should be abolished by inhibition of the Pgp. We used Chinese hamster fibroblasts with different levels of Pgp expression to measure true unidirectional fluxes of rhodamine 123 (R123), a Pgp-transported fluorescent dye that accumulates in mitochondria (hence, its cytosolic concentration remains low at short times after external addition). The unidirectional efflux of R123 was proportional to the level of Pgp expression and was reduced by Pgp inhibitors. The unidirectional influx of R123 was the same in sensitive and resistant cells--i.e., independent of the level of Pgp expression and insensitive to inhibitors of R123 efflux. From these results, we rule out the vacuum cleaner and flippase hypotheses and conclude that Pgp extracts the actively transported substrates from the cytosol and not from the plasma membrane.
Collapse
Affiliation(s)
- G A Altenberg
- Department of Physiology and Biophysics, University of Texas Medical Branch, Galveston 77555-0641
| | | | | | | |
Collapse
|
34
|
Zeuthen T, Stein WD. Cotransport of salt and water in membrane proteins: membrane proteins as osmotic engines. J Membr Biol 1994; 137:179-95. [PMID: 8182729 DOI: 10.1007/bf00232587] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- T Zeuthen
- Panum Institute, University of Copenhagen, Denmark
| | | |
Collapse
|
35
|
Shalinsky DR, Heath DD, Jekunen AP, Alcaraz JE, Howell SB. Selective modulation of vinblastine sensitivity by 1,9-dideoxyforskolin and related diterpenes in multidrug resistant tumour cells. Br J Cancer 1993; 67:471-9. [PMID: 8094975 PMCID: PMC1968280 DOI: 10.1038/bjc.1993.89] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The ability of 1,9-dideoxyforskolin (DDF), 1-deoxyforskolin (DF) and forskolin to modulate cellular sensitivity to vinblastine (VBL) was examined in drug-sensitive parental KB-3-1 cells and a multidrug-resistant subline, KB-GRC1, derived by transfection of mdr1. Fifty microM DF and forskolin enhanced the 1 h uptake of VBL by 8.0 +/- 0.7 (s.d.) and 4.7 +/- 2.5-fold, respectively, with 50 microM DDF producing a 13.6 +/- 1.9-fold increase. The greater effect of DDF relative to forskolin indicated that the effect was independent of activation of cAMP, and this was supported by a lack of effect of dibutyryl cAMP on the uptake. The effect of these agents on uptake were < or = 1.4-fold in KB-3-1 cells. DDF selectively inhibited initial efflux in cells expressing a functional P-glycoprotein (PGP), but both forskolin and DDF inhibited the terminal phase of efflux irrespective of PGP expression. Neither agent affected membrane permeability of polarisation and forskolin did not enhance the uptake of VBL in protein-free liposomes. At a non-toxic concentration of 20 microM, DDF and forskolin decreased the IC50 of VBL from 18.9 to 2.7 and 13 nM in KB-GRC1 cells, respectively, and DDF acted synergistically with VBL as shown by median effect analysis [combination index = 0.20 +/- 0.05 (s.d.)]. In contrast, these diterpenes did not affect VBL sensitivity in KB-3-1 cells. These results indicate that the diterpenes modulate VBL sensitivity predominantly by inhibiting PGP-mediated efflux activity.
Collapse
Affiliation(s)
- D R Shalinsky
- Department of Medicine and Cancer Center, University of California, San Diego, La Jolla 92093-0812
| | | | | | | | | |
Collapse
|