1
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Cool CD, Kuebler WM, Bogaard HJ, Spiekerkoetter E, Nicolls MR, Voelkel NF. The hallmarks of severe pulmonary arterial hypertension: the cancer hypothesis-ten years later. Am J Physiol Lung Cell Mol Physiol 2020; 318:L1115-L1130. [PMID: 32023082 PMCID: PMC9847334 DOI: 10.1152/ajplung.00476.2019] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Severe forms of pulmonary arterial hypertension (PAH) are most frequently the consequence of a lumen-obliterating angiopathy. One pathobiological model is that the initial pulmonary vascular endothelial cell injury and apoptosis is followed by the evolution of phenotypically altered, apoptosis-resistant, proliferating cells and an inflammatory vascular immune response. Although there may be a vasoconstrictive disease component, the increased pulmonary vascular shear stress in established PAH is caused largely by the vascular wall pathology. In this review, we revisit the "quasi-malignancy concept" of severe PAH and examine to what extent the hallmarks of PAH can be compared with the hallmarks of cancer. The cancer model of severe PAH, based on the growth of abnormal vascular and bone marrow-derived cells, may enable the emergence of novel cell-based PAH treatment strategies.
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Affiliation(s)
- Carlyne D. Cool
- 1Department of Pathology, University of Colorado,
Anschuetz Campus, Aurora, Colorado
| | | | - Harm Jan Bogaard
- 3Amsterdam University Medical Centers, Department of Pulmonary Medicine, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | - Edda Spiekerkoetter
- 4Division of Pulmonary and Critical Care Medicine, Stanford University, Palo Alto, California
| | - Mark R. Nicolls
- 4Division of Pulmonary and Critical Care Medicine, Stanford University, Palo Alto, California
| | - Norbert F. Voelkel
- 3Amsterdam University Medical Centers, Department of Pulmonary Medicine, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
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2
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Abd El-Ghaffar HA, Aladle DA, Farahat SE, Abd El-Hady N. P-Glycoprotein (P-170) expression in acute leukemias. Hematology 2013; 11:35-41. [PMID: 16522547 DOI: 10.1080/10245330400026204] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Abstract
Multidrug resistance (MDR) is still a major obstacle to chemotherapy success in acute myeloid leukemia (AML) and to a less extent acute lymphoblastic leukemia (ALL). Recent studies have shown that the expression of certain gene products mediate the development of resistance to chemotherapeutic agents. The most well characterized of these genes is the multidrug resistance gene MDR-1. This study was planned to study the expression of P-glycoprotein/170 in patients with acute leukemia and the effect of Cyclosporin A (CSA) as a modulator of P-glycoprotein functional activity. The study was carried out on 20 patients with acute leukemia (14 AML cases and 6 ALL cases). In addition, 6 normal individuals served as a reference group. Flow cytometric analysis of P-gp/170 surface expression was performed using UIC-2 MoAb together with the functional assay using Rhodamine 123 (Rh 123) and Cyclosporin A as a modulator.P-gp/170 was expressed on the leukemic cells of 37.5% of relapsed patients (40.0% of AML and 33.3% of ALL cases), whereas 27.2% of de novo patients expressed P-gp/170 (33.3% of AML cases and 0% of ALL cases). The functional activity of MDR-1 gp was 71.4% in AML and 33.3% in ALL patients compared with16.6% in normal lymphocytes. From this study, it is clear that P-gp/170 is expressed to a higher degree in leukemic cells and this is greater in relapsed compared to de novo cases and more in AML than ALL blasts. Functional activity is a more sensitive predictor of chemoresistance than P-gp/170 surface expression.
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MESH Headings
- ATP Binding Cassette Transporter, Subfamily B, Member 1/genetics
- ATP Binding Cassette Transporter, Subfamily B, Member 1/metabolism
- Adolescent
- Adult
- Child
- Child, Preschool
- Drug Resistance, Multiple/genetics
- Drug Resistance, Neoplasm/genetics
- Female
- Flow Cytometry/methods
- Gene Expression Regulation, Leukemic
- Humans
- Leukemia, Myeloid, Acute/genetics
- Leukemia, Myeloid, Acute/metabolism
- Male
- Middle Aged
- Precursor Cell Lymphoblastic Leukemia-Lymphoma/genetics
- Precursor Cell Lymphoblastic Leukemia-Lymphoma/metabolism
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Affiliation(s)
- Hasan A Abd El-Ghaffar
- Faculty of Medicine, Mansoura University, Hematology Unit of Clinical Pathology Department, Mansoura, Egypt.
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3
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Abstract
Advanced breast cancer responds to a range of cytotoxic agents, but resistance always develops. Understanding the mechanisms of resistance may provide new therapeutic options. There are several major groups of resistance mechanisms. 1) The multidrug resistant phenotype. This is due to a membrane pump that can extrude a wide range of anticancer drugs--the P-glycoprotein. It is inhibited by a range of clinically used calcium channel blockers such as nifedipine and verapamil. Several other membrane proteins of 180 KD, 170 KD, 300 KD and 85 KD have been reported and are associated with MDR. 2) Glutathione transferences and detoxification mechanisms. These are a multigene family of enzymes that conjugate glutathione to chemically reactive groups. There are 3 major groups of enzymes--acidic, basic and neutral. They have been implicated in resistance to doxorubicin, melphalan cisplatinum chlorambucil and other alkylating agents. Other protecting systems include metallothionein and selenium dependent glutathione peroxidase. HSP27 confers doxorubicin resistance. 3) Topoisomerase II. DNA topoisomerases are involved in several aspects of DNA metabolism in particular genetic recombination, DNA transcription, chromosome segregation. They are a target for doxorubicin, mitoxantrone, VP16. Low levels of expression are associated with resistance. However, it is oestrogen inducible and this may be of therapeutic value. A novel topo IIb which is more drug resistant has been reported. 4) DNA repair. A score or more of genes are involved in the repair of DNA damage by drugs and radiation. Defective DNA repair may predispose to cancer of the breast and be responsible for adverse radiation reactions. Enhanced repair has been shown to be a mechanism of cisplatinum resistance. Several genes are inducible by DNA damage and may confer resistance e.g. A45. 5) Drug activation. Mitomycin C as well as cyclophosphamide and VP16 require activation for their effects. Low levels of cytochrome p450 reductase are associated with MMC resistance.
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Affiliation(s)
- A L Harris
- Molecular Oncology Laboratory, University of Oxford, John Radcliffe Hospital, Headington, UK
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4
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Majumdar G, Singh AK. P-Glycoprotein Expression in Drug-Resistant Chronic Lymphoproliferative Disorder. Leuk Lymphoma 2009; 5:387-90. [DOI: 10.3109/10428199109067633] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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5
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Garattini S. Pharmacokinetics in cancer chemotherapy. Eur J Cancer 2006; 43:271-82. [PMID: 17174548 DOI: 10.1016/j.ejca.2006.10.015] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2006] [Accepted: 10/30/2006] [Indexed: 11/26/2022]
Affiliation(s)
- Silvio Garattini
- Istituto di Ricerche Farmacologiche Mario Negri, Via Eritrea 62, 20157 Milano, Italy.
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6
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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.
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Affiliation(s)
- Suresh Katragadda
- University of Missouri-Kansas City, Division of Pharmaceutical Sciences, School of Pharmacy, 64110-2499, USA
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7
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Friedenberg WR, Tallman MS, Brodsky I, Paietta E, Rowe JM, Lee SJ, Rowland KM, Schnetzer GW, Reed JC. Modified VAD and PSC-833 in the treatment of resistant or relapsing chronic lymphocytic leukemia (E4996): a trial of the Eastern Cooperative Oncology Group. Leuk Res 2004; 28:813-9. [PMID: 15203279 DOI: 10.1016/j.leukres.2003.12.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2003] [Accepted: 12/02/2003] [Indexed: 11/28/2022]
Abstract
BACKGROUND & METHOD The role of multidrug resistance (MDR) was investigated in patients with relapsed chronic lymphocytic leukemia (CLL). PSC-833 was added to modified VAD (a 4-day infusion of vincristine, doxorubicin, with oral dexamethasone, every 3 weeks), in an attempt to improve the response rate (21%) in a prior study. Laboratory tests to determine MDR and apoptosis proteins were correlated with response. RESULTS Two of the seven MDR-positive cases and one of the four MDR-negative patients achieved a partial response (no significant difference). No significant correlation with response was found in any of the laboratory tests for apoptosis. CONCLUSION VAD plus PSC-833 had the same (21%) partial response rate as a prior ECOG study without PSC-833. No correlation of response with MDR or apoptosis testing was found. Other drug resistance factors must play a significant role in determining the response of relapsed patients with CLL.
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MESH Headings
- Aged
- Antineoplastic Combined Chemotherapy Protocols/therapeutic use
- Cyclosporins/therapeutic use
- Dexamethasone/therapeutic use
- Doxorubicin/therapeutic use
- Drug Resistance, Multiple
- Drug Therapy, Combination
- Female
- Humans
- Leukemia, Lymphocytic, Chronic, B-Cell/drug therapy
- Leukemia, Lymphocytic, Chronic, B-Cell/pathology
- Male
- Middle Aged
- Neoplasm Recurrence, Local/drug therapy
- Neoplasm Recurrence, Local/pathology
- Vincristine/therapeutic use
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8
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Kivekäs I, Vilpo L, Vilpo J. Relationships of in vitro sensitivities tested with nine drugs and two types of irradiation in chronic lymphocytic leukemia. Leuk Res 2002; 26:1035-41. [PMID: 12363473 DOI: 10.1016/s0145-2126(02)00050-4] [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: 11/19/2022]
Abstract
Extensive research into mechanisms of cytotoxic drug and irradiation resistance have produced few clinically encouraging results. In this report, we apply correlation analyses to drug and irradiation response results from a cohort of 36 classical B chronic lymphocyte leukemia (CLL) patients. Nine drugs and two types of irradiation were selected according to their usefulness in CLL therapy or on the basis of their otherwise interesting mechanisms of action. Part of the results concerning individual drugs have been previously published, but new correlation analyses are presented in this paper. Altogether 2376 duplicate cultures were performed in order to determine ID(80) values, i.e. doses causing an 80% inhibition in 4-day cultures when leucine incorporation was used as an indicator of cells vitality. Non-parametric Spearman's rank order correlation confirmed a tight relationship between 2-chlorodeoxyadenosine and fludarabine, as expected. Surprisingly, correlation between two P-glycoprotein-dependent drugs, vincristine and doxorubicin, was not demonstrable. A number of entirely unexpected correlations were identified between drugs with very different mechanisms of action: (i) chlorambucil and gamma-irradiation; (ii) 2-chlorodeoxyadenosine and vincristine; (iii) 2-chlorodeoxyadenosine and gamma-irradiation; (iv) fludarabine and cis-platin; (v) doxorubicine and gamma-irradiation; (vi) prednisolone and cyclosporin A; (vii) vincristine and verapamil. Our findings emphasize: (i) the usefulness of fresh tumor cells instead of cell lines in cytotoxicity studies; (ii) the great variation in cytotoxicity in individual patients, i.e. tumor cell heterogeneity, as well as patient heterogeneity; and (iii) an entirely unexpected finding that there were tight relationships in drug and irradiation responses between substances supposed to act with very different mechanisms.
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MESH Headings
- ATP Binding Cassette Transporter, Subfamily B, Member 1/metabolism
- Antigens, CD/metabolism
- Antineoplastic Agents/pharmacology
- Cell Division/drug effects
- Cohort Studies
- Combined Modality Therapy
- Drug Resistance, Neoplasm
- Flow Cytometry
- Humans
- Immunophenotyping
- In Vitro Techniques
- Leukemia, Lymphocytic, Chronic, B-Cell/drug therapy
- Leukemia, Lymphocytic, Chronic, B-Cell/pathology
- Leukemia, Lymphocytic, Chronic, B-Cell/radiotherapy
- Tumor Cells, Cultured/drug effects
- Tumor Cells, Cultured/metabolism
- Tumor Cells, Cultured/radiation effects
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Affiliation(s)
- Ilkka Kivekäs
- Laboratory of Molecular Hematology, Department of Clinical Chemistry, Laboratory Center of Tampere University Hospital, P.O. Box 2000, FIN 33521, Tampere, Finland
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9
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Lucia MB, Rutella S, Leone G, Larocca LM, Vella S, Cauda R. In vitro and in vivo modulation of MDR1/P-glycoprotein in HIV-infected patients administered highly active antiretroviral therapy and liposomal doxorubicin. J Acquir Immune Defic Syndr 2002; 30:369-78. [PMID: 12138343 DOI: 10.1097/00042560-200208010-00001] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
P-glycoprotein (P-gp) transports a wide range of structurally unrelated drugs, such as HIV protease inhibitors (PIs) and cytotoxic compounds such as anthracyclines. Because modification of P-gp phenotype and function is an important underlying mechanism of drug interactions, the current study was conducted in order to evaluate whether highly active antiretroviral therapy (HAART), HIV plasma viral load (VL), or cancer chemotherapy may induce in vivo changes of P-gp phenotype in peripheral blood mononuclear cells (PBMCs) from HIV-infected treatment-naive and -experienced subjects at different stages of HIV infection and/or disease, including patients with HIV-associated Kaposi sarcoma (KS). Our results show that neither HAART nor HIV VL, nor the stage of HIV infection and/or disease, significantly alter P-gp expression on PBMCs. In particular, surface P-gp expression is expressed at low levels by T-cell subsets, B cells, and NK cells, whereas almost all monocytes are double positive and these results are not modified by HIV PI-containing regimens. By contrast, a significant phenotype modification is detected in PBMCs from AIDS/KS patients after challenge with the liposomal formulation of the anthracycline doxorubicin (L-DOX) with the higher expression reached 24 hours after the end of the drug infusion. In addition, accumulation of L-DOX is unaffected by P-gp-mediated drug efflux as documented by in vitro experiments, in sharp contrast to the kinetic of free DOX, based on HIV PI blockade experiments. Finally, P-gp expression was found in KS spindle cells from HIV-infected treatment-naive AIDS/KS patients. We conclude that P-gp phenotype in PBMCs and specific subsets is not altered by HAART and/or HIV, whereas a significant increase is induced by specific anticancer drugs such as L-DOX. Moreover, HIV PIs possess an inhibitory effect on P-gp function that may improve DOX sensitivity in KS spindle cells.
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MESH Headings
- ATP Binding Cassette Transporter, Subfamily B, Member 1/blood
- ATP Binding Cassette Transporter, Subfamily B, Member 1/metabolism
- Adult
- Antineoplastic Agents/administration & dosage
- Antineoplastic Agents/pharmacokinetics
- Antiretroviral Therapy, Highly Active
- B-Lymphocytes/metabolism
- Biological Transport, Active
- Case-Control Studies
- Doxorubicin/administration & dosage
- Doxorubicin/pharmacokinetics
- Female
- HIV Infections/blood
- HIV Infections/complications
- HIV Infections/drug therapy
- HIV Infections/metabolism
- Humans
- In Vitro Techniques
- Killer Cells, Natural/metabolism
- Kinetics
- Liposomes
- Male
- Middle Aged
- Sarcoma, Kaposi/complications
- Sarcoma, Kaposi/drug therapy
- Sarcoma, Kaposi/metabolism
- T-Lymphocyte Subsets/metabolism
- Viremia/blood
- Viremia/complications
- Viremia/drug therapy
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10
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Taylor BJ, Olson DP, Ivy SP. Detection of P-glycoprotein in cell lines and leukemic blasts: failure of select monoclonal antibodies to detect clinically significant Pgp levels in primary cells. Leuk Res 2001; 25:1127-35. [PMID: 11684287 DOI: 10.1016/s0145-2126(01)00085-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Multidrug resistance (MDR) is a salient feature of chemotherapy failure in pediatric patients. One of the most common and well-studied mechanisms implicated in causing MDR is P-glycoprotein (Pgp), an ATP-dependent, transmembrane drug efflux pump. Accurate and reproducible detection of this MDR protein is necessary as it may have important clinical implications. In this study comparing the directly conjugated anti-Pgp monoclonal antibodies UIC2-PE and 15D3-PE to the unconjugated anti-Pgp mAb MRK16, we analyzed cell lines, normal peripheral blood cells, and bone marrow cells from pediatric patients diagnosed with acute myeloid leukemia and acute lymphoblastic leukemia; all samples were also analyzed for Pgp function using rhodamine 123 in order to correlate results from antibody staining with functional activity. For all patient samples evaluated, only MRK16 correlated well with the rhodamine 123 assay. Both the directly conjugated antibodies UIC2-PE and 15D3-PE failed to detect Pgp in almost all cases. Pre-treatment of cells with neuraminidase did not provide a consistent enhancement of antigen detection. Based on these results, we suggest that while UIC2-PE and 15D3-PE may be able to detect the very high levels of Pgp expressing laboratory-cultured cell lines, they are not suitable for clinical application in their currently available conjugated form. When assaying patient samples for Pgp expression and function using flow cytometry, the rhodamine 123 functional assay should be performed in concert with staining with MRK16.
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Affiliation(s)
- B J Taylor
- Division of Hematology-Oncology, Children's National Medical Center, Washington, DC 20010, USA
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11
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De Moerloose B, Dhooge C, Philippé J. Discordance of P-glycoprotein expression and function in acute leukemia. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1999; 457:107-18. [PMID: 10500786 DOI: 10.1007/978-1-4615-4811-9_13] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
Since March 1996, 93 consecutive samples of 45 adults and 41 children, suffering from acute leukemia, were evaluated prospectively for P-glycoprotein (P-gp) expression and function by flow cytometry. P-gp antigen expression was determined with the monoclonal antibodies 4E3 and MRK16. Transport function was assessed by measuring the modulating effect of verapamil on the intracellular retention of Rhodamine 123. P-gp positivity at relapse was not significantly more frequently than at initial diagnosis in our study group, neither with the immunologic assay, nor with the functional test. There was no correlation between the results of the immunologic and the functional test. Discordant test results were observed in 11/41 children (12/44 samples) and 14/45 adults (15/49 samples), independent of the type of leukemia. 2/12 and 2/15 samples scored positive with one of the monoclonal antibodies and were functionally inactive. In 10/12 and 13/15 samples however, an efflux pump was active and dependent of verapamil, but without detectable antigen. The functional flow cytometric assay allows evaluation of non-P-gp efflux pumps and, therefore, is more clinically relevant since it may better identify patients who would benefit from the use of P-gp inhibitors.
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MESH Headings
- ATP Binding Cassette Transporter, Subfamily B, Member 1/analysis
- ATP Binding Cassette Transporter, Subfamily B, Member 1/genetics
- Adolescent
- Adult
- Age Factors
- Bone Marrow/pathology
- Child
- Child, Preschool
- Female
- Flow Cytometry/methods
- Genes, MDR
- Humans
- Infant
- Leukemia, Myeloid, Acute/blood
- Leukemia, Myeloid, Acute/genetics
- Leukemia, Myeloid, Acute/pathology
- Male
- Middle Aged
- Precursor Cell Lymphoblastic Leukemia-Lymphoma/blood
- Precursor Cell Lymphoblastic Leukemia-Lymphoma/genetics
- Precursor Cell Lymphoblastic Leukemia-Lymphoma/pathology
- Recurrence
- Rhodamine 123/pharmacokinetics
- Verapamil/pharmacology
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Affiliation(s)
- B De Moerloose
- Department of Pediatrics, University Hospital Gent, Belgium
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12
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Friedenberg WR, Salzman SA, Phan SM, Burmester JK. Transforming growth factor-beta and multidrug resistance in chronic lymphocytic leukemia. Cancer Immunol Immunother 1999; 16:110-8. [PMID: 10456659 DOI: 10.1007/bf02785844] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Patients with chronic lymphocytic leukemia (CLL) frequently respond to initial treatment, but then become resistant to chemotherapy. Studies have shown one important cause of chemotherapeutic resistance to be multidrug resistance (MDR). To investigate the potential role of MDR and transforming growth factor-beta (TFG-beta), a potent growth inhibitor of B lymphocytes, in the development of chemotherapeutic resistance in CLL, we evaluated 22 CLL patients for loss or mutation of TGF-beta receptors (TbetaR), plasma TGF-beta1 levels, and expression of MDR1 mRNA. Receptor crosslinking and immunoprecipitation experiments did not demonstrate loss of TbetaRs in any patients studied. No relationship between plasma TGF-beta1 levels and expression of MDR1 mRNA was seen. Correlation of plasma TGF-beta1 levels to disease stage revealed a consistent decline in plasma TGF-beta1 levels with advancing disease stage (P = 0.031).
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MESH Headings
- Adult
- Aged
- Aged, 80 and over
- Antineoplastic Agents/pharmacology
- DNA Mutational Analysis
- Disease Progression
- Drug Resistance, Multiple/genetics
- Female
- Gene Expression
- Genes, MDR
- Humans
- Leukemia, Lymphocytic, Chronic, B-Cell/blood
- Leukemia, Lymphocytic, Chronic, B-Cell/drug therapy
- Leukemia, Lymphocytic, Chronic, B-Cell/genetics
- Male
- Middle Aged
- Precipitin Tests
- Receptors, Transforming Growth Factor beta/blood
- Receptors, Transforming Growth Factor beta/genetics
- Reverse Transcriptase Polymerase Chain Reaction
- Transforming Growth Factor beta/blood
- Transforming Growth Factor beta/genetics
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Affiliation(s)
- W R Friedenberg
- Department of Hematology/Oncology, Marshfield Clinic, Wisconsin, USA
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13
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Friedenberg WR, Spencer SK, Musser C, Hogan TF, Rodvold KA, Rushing DA, Mazza JJ, Tewksbury DA, Marx JJ. Multi-drug resistance in chronic lymphocytic leukemia. Leuk Lymphoma 1999; 34:171-8. [PMID: 10350346 DOI: 10.3109/10428199909083394] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
We evaluated 45 chronic lymphocyte leukemia (CLL) patients for the presence of multi-drug resistance (MDR) by the ex vivo techniques: 1) a functional assay utilizing doxorubicin (dox) retention with modulation; 2) a cytotoxicity assay (MTT) with modulation; 3) and four monoclonal antibodies. Ex vivo tests were correlated with disease stage and prior treatment, and were repeated as patients became resistant to alkylating agents, fludarabine and VAD chemotherapy (infusion of vincristine, dox, and oral dexamethasone). The majority of patients (64.4%) were in early stage and were untreated (62.2%). P-glycoprotein (p-gp 170) was detected most frequently by the monoclonal antibody MRK-16 (48%) and by functional modulation of dox retention by PSC-833 (40.6%) and by functional modulation of the MTT assay with vincristine (0.29) and dox (0.39) with PSC-833 at 1.0 microg/mL. Functional modulation of dox retention with PSC-833 was significantly associated with stage, but not with either the MTT assay or any of the monoclonal antibodies. None of the tests correlated with prior chlorambucil treatment. Correlation of dox retention with the monoclonal antibodies was mild to moderate and became stronger following chlorambucil treatment. Three patients who became resistant to VAD were found to express p-gp 170. We conclude that MDR can frequently be detected in patients with CLL. Furthermore, the expression of p-gp 170 increases with advancing stage, but not prior alkylating agent therapy. The functional expression of p-gp 170 increases with advancing stage and prior treatment and correlates well with monoclonal antibody detection (especially MRK-16). Patients who become resistant to VAD more frequently express p-gp 170 by a variety of techniques. PSC-833 is a more potent modulator of MDR than cyclosporin-A (CsA) ex vivo, and correlates better with stage of disease.
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MESH Headings
- ATP Binding Cassette Transporter, Subfamily B, Member 1/metabolism
- Antineoplastic Agents, Alkylating/therapeutic use
- Antineoplastic Combined Chemotherapy Protocols/therapeutic use
- Dexamethasone/administration & dosage
- Doxorubicin/administration & dosage
- Drug Resistance, Multiple
- Humans
- Leukemia, Lymphocytic, Chronic, B-Cell/drug therapy
- Leukemia, Lymphocytic, Chronic, B-Cell/metabolism
- Vidarabine/administration & dosage
- Vidarabine/analogs & derivatives
- Vincristine/administration & dosage
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Affiliation(s)
- W R Friedenberg
- Department of Hematology-Oncology, Marshfield Clinic, WI, USA.
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14
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Abstract
The blood-brain barrier is a major impediment to the entry of many therapeutic drugs into the brain. P-Glycoprotein is an ATP-dependent drug transport protein that is predominantly found in the apical membranes of a number of epithelial cell types in the body, including the blood luminal membrane of the brain capillary endothelial cells that make up the blood-brain barrier. Since P-glycoprotein can actively transport a huge variety of hydrophobic amphipathic drugs out of the cell, it was hypothesized that it might be responsible for the very poor penetration of many relatively large (>400 Da) hydrophobic drugs in the brain, by performing active back-transport of these drugs to the blood. Extensive experiments with in vitro models and with knockout mice lacking blood-brain barrier P-glycoprotein or other animal models treated with blockers of P-glycoprotein have fully confirmed this hypothesis. Absence of functional P-glycoprotein in the blood-brain barrier leads to highly increased brain penetration of a number of important drugs. Depending on the pharmacological target of these drugs in the central nervous system (CNS), this can result in dramatically increased neurotoxicity, or fundamentally altered pharmacological effects of the drug. Given the variety of drugs affected by P-glycoprotein transport, it may be of tremendous therapeutic value to apply these insights to the development of drugs that should have either very poor or very good brain penetration, whichever is preferred for pharmacotherapeutic purposes. The clinical application of P-glycoprotein blockers should also be considered in order to improve the blood-brain barrier permeability of certain drugs that currently display insufficient brain penetration for effective therapy.
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15
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Grey MR, Burgess R, Fisher A, Yin JA. Effect on cell kill of addition of multidrug resistance modifiers cyclosporin A and PSC 833 to cytotoxic agents in chronic lymphocytic leukaemia. Leuk Res 1999; 23:29-35. [PMID: 9933132 DOI: 10.1016/s0145-2126(98)00136-2] [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: 11/23/2022]
Abstract
Expression of P-glycoprotein (Pgp), the drug efflux pump which mediates multidrug resistance (MDR), has been widely reported in chronic lymphocytic leukaemia (CLL) and improved accumulation of daunorubicin has been reported using the MDR reversing agent cyclosporin A (CSA). We have investigated the effects on cell kill of the addition of CSA and its analogue PSC 833 to daunorubicin, doxorubicin, idarubicin, mitozantrone and fludarabine in samples from 51 patients with CLL using an MTT [3(4,5-dimethylthaizol-2-yl)-2,5-diphenyltetrazolium bromide] assay. Pgp expression was assessed by immunocytochemistry using the JSB-1 monoclonal antibody. Of the 51 samples, 10 (20%) were Pgp positive and all of these samples were from treated patients. With the exception of mitozantrone, the addition of CSA and PSC 833 to cytotoxic agents failed to significantly improve cytotoxicity, even in the Pgp positive group. With mitozantrone significant responses were seen in both Pgp positive and negative groups suggesting that the responses were due to direct cytotoxicity of the cytotoxic-modifier combination rather than reversal of MDR. Both CSA and PSC 833 showed significant direct cytotoxicity (P = 0.004 and 0.04 for PSC 833 at 1000 ng/ml and 500 ng/ml respectively; P < 0.001 for both concentrations of CSA). The responses were disappointing compared to the highly significant improvements in cytotoxicity seen using cells from the Pgp positive CEM VLB 100 acute myeloid leukaemia cell line, and it was not possible to demonstrate the superiority of PSC 833 over CSA which is also seen in cell lines. Our data do not support a role for Pgp modifiers in CLL. Further studies using larger numbers of Pgp positive CLL cells and higher doses of PSC 833 would be useful.
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Affiliation(s)
- M R Grey
- University Department of Clinical Haematology, Manchester Royal Infirmary, UK
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16
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Ciaparrone M, Terribile D, Curigliano G, Marra A, Sgambato A, Boninsegna A, Masetti R, Carbone A, Flamini G, Picciocchi A, Cittadini A. P-170 Glycoprotein (MDR) and p53 Expression in Breast Cancer. Breast J 1998; 4:270-6. [PMID: 21223447 DOI: 10.1046/j.1524-4741.1998.440270.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
An immunohistochemical comparative analysis of P-170 glycoprotein and p53 was performed in 37 breast cancer patients who underwent curative resection without preoperative chemotherapy. The antibodies utilized were C-219 and JSB-1 for P-gp and DO-7 for p53. Positive cytoplasmic and membrance positivity for P-gp was found in 22 (59.45%) of the 37 tumor specimens. In comparing tissue immunoreactivity by the specific antibodies, 15 (40.54%) samples showed immunostaining for C-219, 12 (32.43%) for JSB-1, and 5 (23%) for both. P-gp expression was not statistically related with the clinicopathological variables analyzed, that is, age, TNM stage, histologic type, lymph node involvement, tumor diameter, and hormone receptor status. p53 overexpression was observed in 22 (59.45%) of the 37 tumor samples analyzed. There was a significant correlation between p53 overexpression and P-gp positive immunostaining (p = .007). p53 was also significantly correlated with TNM stage (p < .05) and lymph node involvement (p < .02). Our results demonstrated that the three distinct patterns of reactivity with the two antibodies result from the combined expression of each of the three P-gp isoforms. An immunohistochemical analysis with different antibodies may be used to determine and correlate the expression pattern of P-gp isoforms with response to chemotherapy.
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Affiliation(s)
- M Ciaparrone
- Institutes of General Pathology, Catholic Unversity School of Medicine, Rome, Italy Institutes of Surgical Pathology, and Morbid Anatomy, Giovanni XXIII Cancer Research Center, Catholic Unversity School of Medicine, Rome, Italy
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17
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Mongkonsritragoon W, Kimlinger T, Ahmann G, Greipp PR. Is multidrug resistance (P-glycoprotein) an intrinsic characteristic of plasma cells in patients with monoclonal gammopathy of undetermined significance, plasmacytoma, multiple myeloma and amyloidosis? Leuk Lymphoma 1998; 29:577-84. [PMID: 9643571 DOI: 10.3109/10428199809050917] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Multiple myeloma is not a curable disease, and most patients relapse after plateau phase. Drug resistance is a major problem in effective chemotherapy in this kind of disease. Current approaches are aimed at reversing or preventing drug resistance late in the disease. We studied a drug resistance marker, P-glycoprotein (P-gp), in a total of 43 patients with monoclonal gammopathy. This group included eight with monoclonal gammopathy of undetermined significance (MGUS), five with plasmacytoma (PCM), nineteen with multiple myeloma (MM; six newly diagnosed, seven plateau, five refractory, one relapse) and eleven amyloidosis (seven newly diagnosed, four after treatment). Using 3-color flow cytometry, a plasma cell gate was selected on the basis of CD38+/45-(dim) staining and the population was examined for the expression of P-gp using two monoclonal antibodies (MRK16 and UIC2). P-gp expression was positive on marrow plasma cells in 42/43 patients. The resistance index (RI) in these cases (range 2.0-7.07) is comparable to that in the positive cell line KG-1A (3.05-3.08). In 2 of 5 patients with refractory MM, the RI for P-gp (5.4, 6.36) was higher than in plateau phase. These data suggest that relative resistance due to the P-gp mechanism is likely to be an intrinsic property of plasma cells in monoclonal gammopathies and may provide a partial explanation as to why these diseases always relapse. The results of our study support strategies for MDR reversal earlier in the course.
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18
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Maynadié M, Matutes E, Catovsky D. Quantification of P-glycoprotein in chronic lymphocytic leukemia by flow cytometry. Leuk Res 1997; 21:825-31. [PMID: 9393597 DOI: 10.1016/s0145-2126(97)00069-6] [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: 02/05/2023]
Abstract
The P-glycoprotein (P-gp) was investigated in 40 patients with chronic lymphocytic leukemia by immunological, functional and quantitative assays. The proportion of positive cases with the anti-Pgp McAb UIC2 was 30% and increased to 64% after neuraminidase treatment (p = 0.002). Fifty-six per cent of cases were positive with the functional test with rhodamine 123 and verapamil. A negative correlation was found between the number of cells stained with the McAb and the functional test (p = 0.006). The mean of P-gp molecules was 2509 +/- 2805 molecules per cell; these values were higher than in the control K562 cell line in the majority of cases. The number of positive cases and P-gp molecules were higher in treated than in untreated patients (p = 0.01 and 0.07). There were no significant differences with respect to response to treatment, but a higher number of P-gp molecules was found in non-responders. When the results of the functional test were put together with the quantification assay this allowed the detection of 71% non-responders. Our findings suggest that quantification of the P-gp could be of value in the assessment of possible drug resistance in CLL.
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MESH Headings
- ATP Binding Cassette Transporter, Subfamily B, Member 1/blood
- ATP Binding Cassette Transporter, Subfamily B, Member 1/immunology
- Adult
- Aged
- Aged, 80 and over
- Antibiotics, Antineoplastic/pharmacology
- Antibodies, Monoclonal/immunology
- Biological Transport/drug effects
- Calcium Channel Blockers/pharmacology
- Doxorubicin/pharmacology
- Drug Resistance, Neoplasm
- Female
- Flow Cytometry
- Fluorescent Dyes
- Humans
- Leukemia, Erythroblastic, Acute/pathology
- Leukemia, Lymphocytic, Chronic, B-Cell/blood
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/pathology
- Male
- Middle Aged
- Neoplasm Proteins/blood
- Neoplasm Proteins/immunology
- Neuraminidase/pharmacology
- Rhodamine 123
- Rhodamines
- Sensitivity and Specificity
- Verapamil/pharmacology
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Affiliation(s)
- M Maynadié
- Academic Department of Haematology and Cytogenetics, Royal Marsden NHS Trust, London, U.K
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19
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Delville JP, Pradier O, Pauwels O, Van Onderbergen A, Kiss R, Feremans W, Capel P. Comparative study of multidrug resistance evaluated by means of the quantitative immunohistochemical detection of P-glycoprotein and the functional release of rhodamine 123. Am J Hematol 1995; 49:183-93. [PMID: 7604811 DOI: 10.1002/ajh.2830490303] [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: 01/26/2023]
Abstract
The immunological detection of P-Glycoprotein (P-GP) and the functional release of Rhodamine 123 (R123) have been compared in a number of human and murine cancer cell lines, in chemo- and/or radiotherapy-resistant subclones, and in clinical specimens from patients. The chemoresistance level was established from the viability index (IC50) in the presence of doxorubicin. Cytocentrifuge preparations were immunostained with JSB-1 monoclonal antibody followed by the alkaline phosphatase anti-alkaline phosphatase technique. The strength of the reaction was quantified by a digital image analyser. The kinetic incorporation and release of Rhodamine 123 were evaluated by flow cytometry. The parent cell lines and radiotherapy resistant subclones showed a low IC50, were JSB-1 negative and retained R123 during the whole experiment, while the chemoresistant and radio-chemoresistant cell line mutants had a high IC50, were JSB-1 positive, and actively pumped the R123 out of the cells. Good correlations were obtained between the IC50, the digital image analysis, and flow cytometry. The kinetic profile of the R123 release allowed the distinction between typical and atypical multidrug resistance phenotypes. These findings were confirmed in clinical specimens from patients. We conclude that antigenic and functional studies are complementary and are useful in experimental and clinical approaches to multidrug resistance.
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MESH Headings
- ATP Binding Cassette Transporter, Subfamily B, Member 1/analysis
- Animals
- Cell Division
- Drug Resistance, Multiple
- Flow Cytometry
- Humans
- Immunoenzyme Techniques
- Immunohistochemistry
- Kinetics
- Leukemia, Lymphocytic, Chronic, B-Cell/metabolism
- Leukemia, Myeloid, Acute/metabolism
- Lymphoma, Non-Hodgkin/metabolism
- Mice
- Precursor Cell Lymphoblastic Leukemia-Lymphoma/metabolism
- Rhodamine 123
- Rhodamines/metabolism
- Tumor Cells, Cultured
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Affiliation(s)
- J P Delville
- Department of Immunology-Hematology and Transfusion, Hospital Erasme, Brussels, Belgium
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20
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Joncourt F, Oberli-Schrämmli AE, Stadler M, Buser K, Franscini L, Fey MF, Cerny T. Patterns of drug resistance parameters in adult leukemia. Leuk Lymphoma 1995; 17:101-9. [PMID: 7773147 DOI: 10.3109/10428199509051709] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
P-glycoprotein (Pgp), Glutathione (GSH), Glutathione S-Transferase (GST), and O6-Alkylguanine-DNA Alkyltransferase (ATase) were measured in parallel as putative indicators of drug resistance in adult leukemia. The patterns of resistance parameter expression of chronic and acute leukemia were different. In acute leukemia on average all parameters were increased as compared to normal bone marrow. In chronic leukemia GSH and GST were increased, whereas Atase, GPx and frequency of Pgp-expression were low. Treatment with cytostatic drugs did not influence median levels of expression/activity of the resistance parameters. Resistance parameter expression/activity of leukemic cells was also compared with various other tissue and tumor types. Generally the pattern of resistance parameter expression reflected the resistance status of the tissue, constitutively resistant tumor types and their corresponding normal tissue on average having higher levels than leukemic cells and other tissue and tumor types with acquired resistance. For individual patients with acute leukemia, however, none of the parameters was directly correlated with response to treatment.
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Affiliation(s)
- F Joncourt
- University of Berne, Department for Clinical-Experimental Research, Switzerland
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21
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Shustik C, Dalton W, Gros P. P-glycoprotein-mediated multidrug resistance in tumor cells: biochemistry, clinical relevance and modulation. Mol Aspects Med 1995; 16:1-78. [PMID: 7783568 DOI: 10.1016/0098-2997(94)00040-a] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- C Shustik
- Department of Medicine, McGill Cancer Center, Royal Victoria Hospital, Montreal, Quebec, Canada
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22
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Gala JL, McLachlan JM, Bell DR, Michaux JL, Ma DD. Specificity and sensitivity of immunocytochemistry for detecting P-glycoprotein in haematological malignancies. J Clin Pathol 1994; 47:619-24. [PMID: 7916349 PMCID: PMC502088 DOI: 10.1136/jcp.47.7.619] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
AIMS To determine the optimal working conditions of the alkaline phosphatase-antialkaline phosphatase (APAAP) method to establish a specific and sensitive assay for the detection of low numbers of MDR positive cells in patients with hematological malignancies. METHODS Three monoclonal antibodies (C-219, JSB-1, MRK-16) were used for the detection of P-glycoprotein (P-gp) in cell lines and in samples from 43 patients with haematological malignancies. The results of the APAAP method were compared with western blotting for specificity and sensitivity. RESULTS Excellent correlation was obtained between optimised APAAP and western blotting, except in the case of multiple myeloma. JSB-1 seemed to be the more useful monoclonal antibody for the APAAP which was more sensitive than western blotting in its ability to detect single P-gp positive cells. CONCLUSIONS Methods for P-gp detection, as defined by multidrug resistant (MDR) cell lines, are not necessarily optimal and specific for clinical samples and may lead to higher false positive and negative results, according to the conditions and the monoclonal antibodies used.
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Affiliation(s)
- J L Gala
- Haematology Department, Royal North Shore Hospital, Sydney, Australia
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23
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Wulf G, Kluding H, Ho AD, Doerner M, Doehner H, Manegold C, Hunstein W. Multidrug resistance phenotype in patients with chronic lymphocytic leukemia as detected by immunofluorescence (FACS) and northern blot analysis. Leuk Res 1994; 18:475-84. [PMID: 7912754 DOI: 10.1016/0145-2126(94)90085-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The multidrug resistance (MDR) phenotype has been demonstrated to be related to the overexpression of P-glycoprotein, a 170 kDa transmembrane efflux pump. We studied P-glycoprotein expression in 40 patients with chronic B-cell leukemias by FACS analysis using MoAb c219, which recognizes both the MDR1 and the MDR3 gene product. We found significantly elevated P-glycoprotein expression in these patients as compared with normal controls. Patients who had received previous chemotherapy regimens containing MDR-related drugs showed significantly higher P-glycoprotein expression with MoAb c219 than those patients who had been untreated. Northern blot analysis of MDR1 and MDR3 gene expression in 32 of the patients gave a similar result: in the analysis of total RNA four of six patients (66%) pretreated with either vinca alkaloids or anthracyclines were MDR1 positive as opposed to 6 of 26 (23%) who had no treatment or treatment without these agents. In contrast, MDR3 expression was found more frequently (63%), but was randomly distributed in the differently treated groups. Increasing the sensitivity level by analysis of enriched mRNA (polyA+RNA) led to the detection of MDR1 and MDR3 expression all B-CLL patients. We conclude that a basic elevated P-glycoprotein expression is intrinsic in CLL cells, which is possibly upregulated under chemotherapy. This might be responsible for initial and acquired chemotherapy resistance in CLL patients. Follow-up of the B-CLL patients over 46 months showed that the median survival time for MDR1+ patients was 19 months as opposed to 46 months for MDR1- patients (p < 0.01). There was no statistical difference in survival between MDR3+ and MDR3- patients. In the MDR1+ group, eight of nine patients had developed resistance to the therapy with MDR-related drugs. The expression of MDR1 might, therefore, predict treatment failure with MDR-related drugs and be a negative prognostic factor.
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Affiliation(s)
- G Wulf
- Division of Hematology and Oncology, Beth Israel Hospital, Boston, MA 02215
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24
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Abstract
Although, generally speaking, haematological malignancies are chemotherapy-responsive tumours and high remission induction rates are obtained, disease-related death is the rule rather than the exception. The appearance of cell populations, resistant to multidrug-based chemotherapy, constitutes the major problem to achieve cures in these patients. Advances in cell biology have partly contributed to the elucidation of different multidrug resistance (MDR) mechanisms, which enable cells to survive the cytotoxic effects of multiple chemotherapeutic agents. Of these resistance mechanisms, the one that is referred to as classical MDR is the most extensively studied, both in the laboratory as well as in patients, and here we will focus on its clinical relevance in haematological malignancies. The classical MDR phenotype is caused by enhanced cellular drug efflux due to increased activity of a membrane-bound glycoprotein (P-glycoprotein) drug pump, that can pump out anthracyclines, anthracenediones, vinca alkaloids and epipodophyllotoxins, thereby actively lowering the intracellular drug concentrations to sublethal levels. As soon as molecular probes for the detection of MDR cells became available, clinical studies were initiated to answer three main questions. Do human tumor cells express P-glycoprotein? If so, is the expression indicative of a bad prognosis, c.q. resistant disease? And last but not least, can we interfere with the P-glycoprotein drug pump in the patient? Clinical data indicate that classical MDR may be involved in the development of drug resistance, especially in some haematological malignancies, such as acute myelocytic leukaemia (AML), non-Hodgkin's lymphomas (NHL), and multiple myelomas (MM). In almost all types of haematological malignancies, either untreated or treated, elevated P-glycoprotein levels have been reported, ranging from low to high. However, the acquisition of clinical MDR associated with P-glycoprotein expression occurs only in those diseases (for example, AML and MM) that are heavily treated with MDR-related drugs, probably by selection of pre-existing P-glycoprotein-expressing malignant cells. Since P-glycoprotein is found to be expressed on the membrane of normal haemopoietic progenitor cells as well, it seems likely that P-glycoprotein-positive haematological tumours develop by malignant transformation of P-glycoprotein-expressing normal haemopoietic counterparts. Especially for AML, convincing data have been reported in the literature to show that P-glycoprotein expression at diagnosis is a bad prognostic factor that predicts refractoriness. Using in vitro model systems for classical MDR, a large number of agents have been identified that can circumvent P-glycoprotein-mediated drug resistance, the so-called resistance modifying agents (RMA).(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- K Nooter
- Department of Medical Oncology, Rotterdam Cancer Institute, The Netherlands
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25
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Affiliation(s)
- C E Herzog
- National Cancer Institute, Bethesda, MD 20892
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26
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Müller MR, Lennartz K, Nowrousian MR, Dux R, Tsuruo T, Rajewsky MF, Seeber S. Improved flow-cytometric detection of low P-glycoprotein expression in leukaemic blasts by histogram subtraction analysis. CYTOMETRY 1994; 15:64-72. [PMID: 7512893 DOI: 10.1002/cyto.990150111] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Expression of the drug efflux pump P-glycoprotein (PGP) was determined by flow cytometry in human lung cancer cell lines and in leukaemic blasts derived from 60 patients with acute myeloid leukaemia (AML). Cells from the PGP-negative parent cell line H69/P and the multidrug resistant (MDR)-variant H69/LX4 could be clearly distinguished by immunostaining with the anti-PGP monoclonal antibody MRK16. In leukaemic blasts, the differences in fluorescence intensities between samples incubated with the idiotypic nonspecific (control sample) and specific antibody (test sample) were small, resulting in nondisjunct distributions. Only in a few leukaemia specimens were PGP-expressing cells detectable by simple subtraction of histograms using a threshold. Therefore, an improved histogram subtraction analysis, based on curve fitting and a statistical test, was applied to distinguish antigen-positive from antigen-negative cells. Moreover, a multiparametric staining procedure employing propidium iodide (PI) and Hoechst 33342 was used to reduce staining artefacts. By this approach, leukaemic cells with low expression of PGP were detected in 39 out of 60 cases. Subpopulations with strong PGP expression, resulting in disjunct fluorescence distributions, were not observed. Only in 5 out of 60 specimens were PGP expressing cells detected by a conventional subtraction of histograms using a threshold. Comparison of data obtained with or without the multiparametric gating procedure indicated that the increase in sensitivity was mainly due to the application of the data analysis. However, exclusion of cell debris using PI and Hoechst staining properties reduced the deviation of data from mean values. No relation between PGP expression and cell cycle position was observed in either cell lines or in leukaemic blasts.(ABSTRACT TRUNCATED AT 250 WORDS)
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MESH Headings
- ATP Binding Cassette Transporter, Subfamily B, Member 1
- Antineoplastic Combined Chemotherapy Protocols/therapeutic use
- Carcinoma, Small Cell/pathology
- Carrier Proteins/analysis
- DNA, Neoplasm/analysis
- Drug Resistance
- Flow Cytometry
- Humans
- Leukemia, Myeloid, Acute/drug therapy
- Leukemia, Myeloid, Acute/metabolism
- Leukemia, Myeloid, Acute/pathology
- Lung Neoplasms/pathology
- Membrane Glycoproteins/analysis
- Neoplasm Proteins/analysis
- Neoplastic Stem Cells/metabolism
- Neoplastic Stem Cells/pathology
- Palliative Care
- Remission Induction
- Salvage Therapy
- Subtraction Technique
- Tumor Cells, Cultured
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Affiliation(s)
- M R Müller
- Department of Medical Oncology, West German Cancer Centre, Essen
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27
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Abstract
Multidrug resistance represents a major obstacle in the successful therapy of neoplastic diseases. Studies have demonstrated that this form of drug resistance occurs in cultured tumor cell lines as well as in human cancers. P-glycoprotein appears to play an important role in such cells by acting as an energy-dependent efflux pump to remove various natural-product drugs from the cell before they have a chance to exert their cytotoxic effects. Using the tools of molecular biology, studies are beginning to reveal the true incidence of multidrug resistance, as mediated by the MDR1 gene, in the clinical setting. It has been demonstrated, at least in the laboratory, that resistance mediated by P-glycoprotein may be modulated by a wide variety of compounds, including verapamil and cyclosporine A. These are compounds which, by themselves, generally have little or no effect on the tumor cells, but when used in conjunction with antineoplastic agents act to decrease, and in some instances eliminate, drug resistance. The mechanism(s) by which these agents act to reverse resistance is not fully understood. Clinical trials to modulate P-glycoprotein activity are now under way to determine whether such strategies will be feasible. The detection of the P-glycoprotein in patient samples is very important in the design of these studies, as it appears that drug-resistant cells lacking P-glycoprotein will be unaffected by agents such as verapamil. Clinical studies are needed in which patients are stratified into chemotherapy protocols based on levels of MDR1 mRNA or P-glycoprotein expression in the primary tumors. Several research areas have been identified that are important to the transfer of the discovery of the MDR1 gene and its protein product from the research laboratory to the clinical environment. There is an immediate need for comprehensive information on the prevalence and levels of expression of the human MDR genes and their protein products in human organs and tissues. Data are needed on P-glycoprotein levels in specific subpopulations (e.g., according to age, sex, race, and diet), and the study of the heterogeneity and variability of expression of P-glycoprotein in normal human tissues should be given high priority. Since early studies have indicated some successes in identifying patients with classic multidrug resistance who might be responsive to chemosensitization, it can be anticipated that clinical research will accelerate in this area. The next wave of clinical studies will provide clinical investigators with opportunities to develop and evaluate P-glycoprotein tests and correlate test results with clinical outcomes.
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Affiliation(s)
- W T Bellamy
- Department of Pathology, University of Arizona, Tucson 85724
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28
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Sparrow RL, Hall FJ, Siregar H, Van der Weyden MB. Common expression of the multidrug resistance marker P-glycoprotein in B-cell chronic lymphocytic leukaemia and correlation with in vitro drug resistance. Leuk Res 1993; 17:941-7. [PMID: 7901453 DOI: 10.1016/0145-2126(93)90041-i] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The expression of P-glycoprotein (Pgp), which is associated with multidrug resistance (MDR), was investigated in 20 B-cell chronic lymphocytic leukaemia (B-CLL) patients by flow cytometry using two Pgp-specific monoclonal antibodies (mAb), MRK-16 which recognizes an extracellular epitope, and JSB-1 which recognizes an intracellular epitope. Sixteen (80%) patients were positive with MRK-16 whereas all patients were positive with JSB-1. The proportion of Pgp-positive lymphocytes from each patient sample varied from 2-94% for MRK-16 and 20-93% for JSB-1. There was no correlation between the level of positivity and disease stage or treatment history. In vitro drug resistance to vincristine (VCR) and doxorubicin (DOX) was determined by the colorimetric MTT assay. All patients were resistant to one or both drugs being consistent with the expression of Pgp. There was no correlation between the level of resistance and disease stage or drug treatment. We investigated the expression of Pgp in the normal counterpart of the B-CLL cells, CD5+CD19+ B-lymphocytes. A minor subpopulation (3%) of CD5+CD19+ lymphocytes isolated from normal controls expressed Pgp suggesting that these cells may be the potential precursors to the B-CLL cell. We conclude that Pgp expression and drug resistance are inherent characteristics of the B-CLL lymphocyte.
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Affiliation(s)
- R L Sparrow
- Pathology Service, Alfred Hospital, Prahran, Victoria, Australia
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29
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Schinkel AH, Arceci RJ, Smit JJ, Wagenaar E, Baas F, Dollé M, Tsuruo T, Mechetner EB, Roninson IB, Borst P. Binding properties of monoclonal antibodies recognizing external epitopes of the human MDR1 P-glycoprotein. Int J Cancer 1993; 55:478-84. [PMID: 8104165 DOI: 10.1002/ijc.2910550326] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Monoclonal antibodies (MAbs) recognizing external epitopes of the human MDR1 P-glycoprotein have been used both for the detection of multidrug-resistant cells and as specific inhibitors of P-glycoprotein-mediated multidrug resistance. Using a panel of recently developed transfected or transgenic cell lines containing variants of the human MDR1 and MDR3 P-glycoproteins, we have compared the specificity and binding properties of the previously isolated MAbs MRK16, HYB-241, UIC2 and 4E3, and of the newly isolated MAb 7G4. The removal of 1, 2 or all 3 of the N-glycosylation sites present in the first extracellular loop of MDR1 P-glycoprotein did not significantly affect the binding of these MAbs. In contrast, 20 amino acid deletion in the first extracellular loop of MDR1 P-glycoprotein completely abolished binding of UIC2, whereas the binding of all other MAbs was hardly affected. None of the MAbs tested bound detectably to cell lines containing a high level of the human MDR3 P-glycoprotein. The differences in the binding specificity between UIC2 and the other tested antibodies parallel the reported functional differences in the ability of these antibodies to inhibit P-glycoprotein-mediated drug efflux.
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Affiliation(s)
- A H Schinkel
- Division of Molecular Biology, The Netherlands Cancer Institute, Amsterdam
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30
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Abstract
Multidrug resistance hampers successful chemotherapy in many haematological neoplasms and is mediated by several cellular proteins. In some cases, the genes encoding these proteins have been shown to confer resistance on transfer to drug-sensitive cell lines. This is true for the efflux pump product of the MDR1 gene, P-170. Upregulation of enzymes such as GST has been observed, although the contribution of this enzyme in drug resistance expressed by malignant haematopoietic cells is still uncertain. Cells also appear to be able to downregulate enzymes which are drug targets. Examples include the decrease in Topo II which accompanies the resistance shown by cells to VP-16 and VM-26. Although many reports include both presentation and relapsed patients, there are few data on samples drawn from the same patients before and after chemotherapy. While P-170 and GST appear to be raised more often in cells from resistant and relapsed disease, it is quite clear that such mechanisms can be active in de novo malignancy and do not necessarily emerge as a consequence of prior chemotherapy. Methods of detecting drug resistance are reviewed here; these include in vitro cellular assays for drug toxicity, and molecular, immunological and functional detection of P-170 or Topo II. The clinical evaluation of such assays is only just beginning and some of the data are contradictory. To some extent, this may reflect the complex way in which the various resistance mechanisms may interact. Nevertheless, there are some encouraging early signs that the application of these assays to clinical material will yield valuable data on the relative contributions of these mechanisms and on ways in which they may be overcome. At present, much attention has focused on the potential of agents which prevent the P-170 efflux pump from exporting cytotoxics from the cell. This is likely to be only the first of new therapies arising from an improved understanding of multidrug resistance. More immediately, assays for multidrug resistance and its parameters may find their place as routine diagnostic and prognostic tools in the laboratory.
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Affiliation(s)
- P Baines
- Department of Haematology, University of Wales College of Medicine, Heath Park, Cardiff, UK
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31
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Marks DC, Davey MW, Davey RA, Kidman AD. Differentiation and multidrug resistance in response to drug treatment in the K562 human leukaemia cell line. Br J Haematol 1993; 84:83-9. [PMID: 8101722 DOI: 10.1111/j.1365-2141.1993.tb03028.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The relationship between differentiation and P-glycoprotein expression in response to chemotherapeutic drugs was studied in the K562 human leukaemia cell line by treatment with low, but clinically achievable levels of vinblastine and epirubicin. Resistant sublines were easily generated with the multidrug resistant phenotype being expressed in response to drug treatment as low as 1 ng/ml vinblastine and 10 ng/ml epirubicin. These sublines showed stable but heterogeneous expression of P-glycoprotein as revealed by immunocytochemistry, and confirmed by cloning. This heterogeneity was maintained over 18 months with intermittent drug treatment. While selection for resistance induced erythroid and myeloid differentiation, expression of P-glycoprotein was not correlated with the stem cell antigen CD34 or with specific markers of erythroid or myeloid differentiation.
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MESH Headings
- ATP Binding Cassette Transporter, Subfamily B, Member 1
- Antigens, Neoplasm/analysis
- Blotting, Western
- Carrier Proteins/analysis
- Carrier Proteins/drug effects
- Cell Differentiation/drug effects
- Drug Resistance
- Epirubicin/pharmacology
- Humans
- In Vitro Techniques
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/immunology
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/pathology
- Membrane Glycoproteins/analysis
- Membrane Glycoproteins/drug effects
- Neoplasm Proteins/analysis
- Neoplasm Proteins/drug effects
- Tumor Cells, Cultured
- Verapamil/pharmacology
- Vinblastine/pharmacology
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Affiliation(s)
- D C Marks
- Neurobiology Unit, School of Biological and Biomedical Sciences, University of Technology, Sydney, N.S.W., Australia
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32
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Affiliation(s)
- D Rischin
- Ontario Cancer Institute, Toronto, Canada
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33
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Nooter K, Sonneveld P. Multidrug resistance (MDR) genes in haematological malignancies. Cytotechnology 1993; 12:213-30. [PMID: 7765326 DOI: 10.1007/bf00744665] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The emergence of drug resistant cells is one of the main obstacles for successful chemotherapeutic treatment of haematological malignancies. Most patients initially respond to chemotherapy at the time of first clinical admission, but often relapse and become refractory to further treatment not only to the drugs used in the first treatment but also to a variety of other drugs. Laboratory investigations have now provided a cellular basis for this clinical observation of multidrug resistance (MDR). Expression of a glycoprotein (referred to as P-glycoprotein) in the membrane of cells made resistant in vitro to naturally occurring anticancer agents like anthracyclines, Vinca alkaloids and epipodophyllotoxins, has been shown to be responsible for the so-called classical MDR phenotype. P-glycoprotein functions as an ATP-dependent, unidirectional drug efflux pump with a broad substrate specificity, that effectively maintains the intracellular cytotoxic drug concentrations under a non-cytotoxic threshold value. Extensive clinical studies have shown that P-glycoprotein is expressed on virtually all types of haematological malignancies, including acute and chronic leukaemias, multiple myelomas and malignant lymphomas. Since in model systems for P-glycoprotein-mediated MDR, drug resistance may be circumvented by the addition of non-cytotoxic agents that can inhibit the outward drug pump, clinical trials have been initiated to determine if such an approach will be feasible in a clinical situation. Preliminary results suggest that some haematological malignancies, among which are acute myelocytic leukaemia, multiple myeloma and non-Hodgkin's lymphoma, might benefit from the simultaneous administration of cytotoxic drugs and P-glycoprotein inhibitors. However, randomised clinical trials are needed to evaluate the use of such resistance modifiers in the clinic.
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Affiliation(s)
- K Nooter
- Department of Medical Oncology, Rotterdam Cancer Institute, The Netherlands
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34
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Wall DM, Sparrow R, Hu XF, Nadalin G, Zalcberg JR, Marschner IC, Van der Weyden M, Parkin JD. Clinical application of a rapid, functional assay for multidrug resistance based on accumulation of the fluorescent dye, fluo-3. Eur J Cancer 1993; 29A:1024-7. [PMID: 8098947 DOI: 10.1016/s0959-8049(05)80216-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A rapid and simple functional assay for P-glycoprotein (Pgp) using flow cytometry to measure the accumulation of the flurophore fluo-3 has been applied to samples from patients with B-cell chronic lymphocytic leukaemia (B-CLL). Peripheral blood lymphocytes from 37 patients with B-CLL were studied for Pgp. Pgp expression, using MRK-16, a monoclonal antibody recognising an external surface epitope of Pgp, was detected in 92% of patients with B-CLL. The functional assays for Pgp expression were positive in 78 and 59% of patients using the fluo-3 and doxorubicin (dox) assays, respectively. When compared with the MRK-16 assay, the fluo-3 assay had a sensitivity of 82% compared to a sensitivity of 56% for the dox assay (P = 0.004). The specificity of the fluo-3 and dox assays could not be evaluated because of the low number of MRK-16 negative CLL cells.
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MESH Headings
- ATP Binding Cassette Transporter, Subfamily B, Member 1
- Aged
- Aged, 80 and over
- Aniline Compounds/metabolism
- Carrier Proteins/analysis
- Doxorubicin/metabolism
- Drug Resistance
- Flow Cytometry
- Fluorescent Dyes/metabolism
- Humans
- Leukemia, Lymphocytic, Chronic, B-Cell/blood
- Leukemia, Lymphocytic, Chronic, B-Cell/drug therapy
- Leukemia, Lymphocytic, Chronic, B-Cell/metabolism
- Lymphocytes/metabolism
- Membrane Glycoproteins/analysis
- Middle Aged
- Neoplasm Proteins/blood
- Sensitivity and Specificity
- Xanthenes/metabolism
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Affiliation(s)
- D M Wall
- Department of Haematology, Heidelberg Repatriation Hospital
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Abstract
Multidrug resistance (MDR) is a major problem in cancer chemotherapy. As P-glycoprotein is the key molecule in MDR, many investigators have constructed anti-P-glycoprotein monoclonal antibodies (MAbs). Those antibodies, including MRK16 and C219, were used for elucidation of the mechanism of MDR and for overcoming of MDR. This article describes the characterization of the antibodies against the P-glycoprotein and other proteins of multidrug-resistant tumor cells, and discusses the therapeutic implication of the antibodies.
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Affiliation(s)
- Y Heike
- Pharmacology Division, National Cancer Center Research Institute, Tokyo, Japan
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36
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Tiirikainen MI, Syrjälä MT, Jansson SE, Krusius T. Flow cytometric analysis of P-glycoprotein in normal and leukemic cells. Ann Hematol 1992; 65:124-30. [PMID: 1356449 DOI: 10.1007/bf01695811] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Classical multidrug resistance is characterized by overexpression of a membrane protein, P-glycoprotein, which acts like a drug-extruding pump, reducing accumulation of cytotoxic drugs inside malignant cells. We have developed a simple method for detecting an intracellular epitope of P-glycoprotein in normal and leukemic cells by the monoclonal antibody JSB-1 and fluorescence-activated flow cytometry. Permeabilization of blood and bone marrow cells in unprocessed samples is achieved by a commercially available red blood cell lysing solution which excellently preserves the light scatter properties of leukocytes. The method is suitable for analyzing samples in clinical routine. Lower than 1% reactivity was seen in the lymphoid gate of normal peripheral blood and bone marrow samples as compared with over 60% of reacting cells in some leukemic samples. Twelve patients with acute de novo leukemia were studied at presentation, 13 patients at a refractory stage, and 28 in remission. There was a positive correlation between the P-glycoprotein and the CD34 expression in acute myelogenous leukemia and an association between the P-glycoprotein expression and the blast count in both acute myelogenous and lymphatic leukemias.
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Affiliation(s)
- M I Tiirikainen
- Finnish Red Cross, Blood Transfusion Service, Helsinki, Finland
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37
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Ludescher C, Thaler J, Drach D, Drach J, Spitaler M, Gattringer C, Huber H, Hofmann J. Detection of activity of P-glycoprotein in human tumour samples using rhodamine 123. Br J Haematol 1992; 82:161-8. [PMID: 1358171 DOI: 10.1111/j.1365-2141.1992.tb04608.x] [Citation(s) in RCA: 140] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Based on the fluorescent properties of the dye rhodamine 123 (Rh123), which is transported by the membrane efflux pump P-glycoprotein (P-gp), we developed a functional flow cytometric assay for the detection of multidrug-resistant (MDR) cells. Using drug sensitive cell lines (KB-3-1) and MDR mutants (KB-8-5, KB-C1) experimental conditions were established that enabled demonstration of significant differences in Rh123 efflux and accumulation. Subsequently we investigated the applicability of this functional assay for the prediction of MDR in human peripheral blood and bone marrow samples. Using two-colour flow cytometry, the leukaemic blast cells of six patients suffering from acute myeloid leukaemia (AML) were analysed. In three cases the blast cells showed a rapid and marked Rh123 efflux. In the presence of MDR inhibitors these cells retained Rh123. To determine whether the efflux of Rh123 was associated with P-gp expression, the leukaemic cells were stained with the monoclonal antibody MRK-16. In addition extracted RNA was analysed by polymerase chain reaction to evaluate the expression of mdr 1 mRNA. In all three Rh123+ cases mdr 1 mRNA was detectable whereas only one AML case expressed P-gp. In comparing Rh123 with daunorubicin, which also allows the detection of MDR cells, accumulation studies proved Rh123 to be the more sensitive drug for flow cytometric MDR screening. Additionally, two-colour flow cytometry was much easier to perform with Rh123 than with daunorubicin. Our results indicate that flow cytometric measurement of Rh123 accumulation/efflux proves applicable to detect MDR cells in heterogenous clinical samples.
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Affiliation(s)
- C Ludescher
- Department of Internal Medicine, University of Innsbruck, Austria
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38
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Barrand MA, Twentyman PR. Differential recognition of mdr1a and mdr1b gene products in multidrug resistant mouse tumour cell lines by different monoclonal antibodies. Br J Cancer 1992; 65:239-45. [PMID: 1346747 PMCID: PMC1977717 DOI: 10.1038/bjc.1992.48] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
An immunocytochemical method was used to test the reactivity of the anti-P-glycoprotein antibodies, C219, MRK 16, JSB-1 and 265/F4 against multidrug resistant (MDR) variants derived from the human small cell lung carcinoma line, NCI-H69, the mouse fibrosarcoma line, RIF-1 and the mouse mammary tumour cell line, EMT6. C219 produced positive staining in MDR variants of both human and mouse tumour cell lines. MRK 16 and JSB-1 however recognised P-glycoprotein only in the human MDR cell lines and not in the mouse MDR cells. 265/F4 appeared the most selective of the monoclonal antibodies used, producing positive staining of MDR variants derived from the RIF-1 line, but not of MDR variants derived from the EMT6 line. Total RNA was prepared from the mouse cell lines and, following reverse transcription, cDNA sequences were amplified by the polymerase chain reaction with primers specific for either the murine mdr1a or the mdr1b genes. From this it was possible to show that only the mdr1a gene is overexpressed in the resistant EMT6 lines that do not stain with 265/F4 whereas both mdr1a and mdr1b are overexpressed in the positively staining resistant fibrosarcoma line, RIF/1.0. Low level expression of mdr1b was detected in the sensitive parent RIF-1 cells and increasing levels of expression correlated with increasing resistance in the lines, RIF/0.1, 0.2, 0.4 and 1.0. Expression of mdr1a was found only in the more resistant fibrosarcoma cell lines. It seems that 265/F4 recognises only the mdr1b P-glycoprotein. Western blotting confirmed that this antibody detects a 170 kDa protein only in membranes derived from the resistant fibrosarcoma cells. 265/F4 may thus be used to distinguish between the murine P-glycoprotein isoforms so revealing differences between tumour cell lines in cellular localisation and in the time of appearance of mdr1a and mdr1b P-glycoprotein following drug exposure.
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Affiliation(s)
- M A Barrand
- MRC Clinical Oncology and Radiotherapeutics Unit, Cambridge, UK
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39
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List AF, Spier CM, Cline A, Doll DC, Garewal H, Morgan R, Sandberg AA. Expression of the multidrug resistance gene product (P-glycoprotein) in myelodysplasia is associated with a stem cell phenotype. Br J Haematol 1991; 78:28-34. [PMID: 1675116 DOI: 10.1111/j.1365-2141.1991.tb04378.x] [Citation(s) in RCA: 95] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Previous studies have indicated relative resistance to chemotherapy in the myelodysplastic syndromes (MDS) and associated acute leukaemia. To determine if multidrug resistance may contribute to chemoresistance in these disorders, we studied bone marrow specimens for P-glycoprotein expression (P-GP) by immunocytochemical staining with monoclonal antibodies reactive with cytoplasmic (C219) or surface epitopes (MRK16) of P-GP. Forty-five case specimens from 43 patients were studied, including 32 cases of primary MDS, seven cases of acute myeloid leukaemia (AML) following MDS, and six therapy-related haematological disorders. Cytogenetic analysis was available on 36 specimens. Two staining patterns were detected: (1) cytoplasm and plasma membrane, and (2) staining restricted primarily to the nuclear-cytoplasmic junction. P-GP was detected in seven (22%) cases of primary MDS, four (57%) cases of AML evolving from MDS, and five (83%) cases of therapy-related haematological disorders. Expression of P-GP was restricted to blasts and leukaemic monocytes, and was otherwise absent from terminally differentiated blood cells. Analysis of the relation between P-GP expression and reactivity with the human progenitor cell antigen CD34, revealed a highly significant association (P = 0.001). P-GP reactivity was distributed equally among normal and abnormal karyotypes and did not correlate with specific cytogenetic abnormalities. These findings indicate that multidrug resistance in MDS and karyotypically-related haematological disorders is closely linked to a stem cell phenotype and may contribute to chemoresistance in these disorders.
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Affiliation(s)
- A F List
- University of Arizona Health Sciences Center, Tucson
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40
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Abstract
Resistance of malignant cells to cytotoxic agents is often a limiting factor to successful chemotherapy. The classical multidrug resistance is characterised by overexpression of a membrane protein, P-glycoprotein, which acts like a drug extruding pump reducing accumulation of cytotoxic agents inside malignant cells, thereby preventing their function. Resistance is expressed simultaneously towards several structurally unrelated drugs. P-glycoprotein is also expressed in many normal human tissues, e.g., in the gastrointestinal tract, and this may be the reason for intrinsic resistance observed clinically in cancers derived from certain tissues. More often multidrug resistance is acquired during chemotherapy. The physiological function of P-glycoprotein is still unknown but it may have a role in cellular detoxification and secreting mechanisms. Interest in the phenomenon of multidrug resistance centres on the correlation of P-glycoprotein expression to clinical drug resistance. Another goal is to find mechanisms by which the function of P-glycoprotein as a multidrug transporter is prevented and drug resistance reversed.
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