1
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Tsirigotakis N, Christodoulou V, Ntais P, Mazeris A, Koutala E, Messaritakis I, Antoniou M. Geographical Distribution of MDR1 Expression in Leishmania Isolates, from Greece and Cyprus, Measured by the Rhodamine-123 Efflux Potential of the Isolates, Using Flow Cytometry. Am J Trop Med Hyg 2016; 94:987-92. [PMID: 27001764 DOI: 10.4269/ajtmh.15-0658] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Accepted: 01/05/2016] [Indexed: 11/07/2022] Open
Abstract
Leishmaniasis, a neglected vector-borne disease caused by the protozoan parasite Leishmania, is encountered in 98 countries causing serious concerns to public health. The most alarming is the development of parasite drug resistance, a phenomenon increasingly encountered in the field rendering chemotherapy ineffective. Although resistance to drugs is a complex phenomenon, the rate of efflux of the fluorescent dye Rhodamine-123 from the parasite body, using flow cytometry, is an indication of the isolate's ability to efflux the drug, thus avoiding death. The rate of efflux measured 275 Leishmania strains, isolated from patients and dogs from Greece and Cyprus, was measured and mapped to study the geographical distribution of the multidrug resistance (MDR) gene expression as an indication of the drug resistance of the parasite. The map showed that out of the seven prefectures, where dogs presented high efflux rates, five also had patients with high efflux rates. In one, out of the 59 prefectures studied, the highest number of isolates with efflux slope α > 1, in both human and dog isolates, was found; a fact which may suggest that spread of drug resistance is taking place. The virulence of the Leishmania strains, assessed after infecting human macrophages of the THP-1 cell line, fluctuated from 1% to 59.3% with only 2.5% of the isolates showing infectivity > 50%. The most virulent strains were isolated from Attica and Crete.
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Affiliation(s)
- Nikolaos Tsirigotakis
- Laboratory of Clinical Bacteriology, Parasitology, Zoonoses and Geographical Medicine, Faculty of Medicine, University of Crete, Crete, Greece; Veterinary Services of Cyprus, Nicosia, Cyprus; Veterinary Services of Lasithi prefecture, Crete, Greece; Laboratory of Flow Cytometry, Faculty of Medicine, University of Crete, Crete, Greece
| | - Vasiliki Christodoulou
- Laboratory of Clinical Bacteriology, Parasitology, Zoonoses and Geographical Medicine, Faculty of Medicine, University of Crete, Crete, Greece; Veterinary Services of Cyprus, Nicosia, Cyprus; Veterinary Services of Lasithi prefecture, Crete, Greece; Laboratory of Flow Cytometry, Faculty of Medicine, University of Crete, Crete, Greece
| | - Pantelis Ntais
- Laboratory of Clinical Bacteriology, Parasitology, Zoonoses and Geographical Medicine, Faculty of Medicine, University of Crete, Crete, Greece; Veterinary Services of Cyprus, Nicosia, Cyprus; Veterinary Services of Lasithi prefecture, Crete, Greece; Laboratory of Flow Cytometry, Faculty of Medicine, University of Crete, Crete, Greece
| | - Apostolos Mazeris
- Laboratory of Clinical Bacteriology, Parasitology, Zoonoses and Geographical Medicine, Faculty of Medicine, University of Crete, Crete, Greece; Veterinary Services of Cyprus, Nicosia, Cyprus; Veterinary Services of Lasithi prefecture, Crete, Greece; Laboratory of Flow Cytometry, Faculty of Medicine, University of Crete, Crete, Greece
| | - Eleni Koutala
- Laboratory of Clinical Bacteriology, Parasitology, Zoonoses and Geographical Medicine, Faculty of Medicine, University of Crete, Crete, Greece; Veterinary Services of Cyprus, Nicosia, Cyprus; Veterinary Services of Lasithi prefecture, Crete, Greece; Laboratory of Flow Cytometry, Faculty of Medicine, University of Crete, Crete, Greece
| | - Ippokratis Messaritakis
- Laboratory of Clinical Bacteriology, Parasitology, Zoonoses and Geographical Medicine, Faculty of Medicine, University of Crete, Crete, Greece; Veterinary Services of Cyprus, Nicosia, Cyprus; Veterinary Services of Lasithi prefecture, Crete, Greece; Laboratory of Flow Cytometry, Faculty of Medicine, University of Crete, Crete, Greece
| | - Maria Antoniou
- Laboratory of Clinical Bacteriology, Parasitology, Zoonoses and Geographical Medicine, Faculty of Medicine, University of Crete, Crete, Greece; Veterinary Services of Cyprus, Nicosia, Cyprus; Veterinary Services of Lasithi prefecture, Crete, Greece; Laboratory of Flow Cytometry, Faculty of Medicine, University of Crete, Crete, Greece
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2
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Drug resistance in natural isolates of Leishmania donovani s.l. promastigotes is dependent of Pgp170 expression. PLoS One 2013; 8:e65467. [PMID: 23776486 PMCID: PMC3679129 DOI: 10.1371/journal.pone.0065467] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Accepted: 04/28/2013] [Indexed: 01/24/2023] Open
Abstract
Resistance of pathogens to drugs is a growing concern regarding many diseases. Parasites like Leishmania, Plasmodium and Entamoeba histolytica; and neoplastic cells, present the multidrug-resistant phenotype rendering chemotherapy ineffective. The acquired resistance of Leishmania to antimony has generated intense research on the mechanisms involved but the question has not yet been resolved. To test the hypothesis that drug efflux in Leishmania, as measured by flow cytometry using the fluorescent dye Rhodamine-123, is largely dependent on the number of efflux pumps an isolate can express, the amount of Pgp 170 molecules was assessed in ten field isolates (5 “resistant” and 5 “susceptible”) using: Western Blotting, Confocal and Transmission Electron Microscopy, and proteomics. Their survival after exposure to three antileishmanial drugs, in vitro, was evaluated and clinical data were compared to the in vitro results. All isolates were resistant to Glucantime but susceptible to Miltefosine, whilst Amphotericin B was more effective on the “susceptible” isolates. The MDR gene, expressing the transmembrane efflux pump Pgp 170, appears to play a key role in the phenomenon of drug resistance. When “susceptible” versus “resistant” parasites were compared, it was shown that the higher the number of Pgp 170 molecules the higher the Rhodamine-123 efflux from the parasite body and, when exposed to the drug, the number of efflux pumps increased. However, the rate of this increase was not linear and it is possible that there is a maximum number of Pgp 170 molecules an isolate can express. Nevertheless, the phenomenon is a complex one and other factors and proteins are involved in which the HSP-70 group proteins, detected in the “resistant” isolates, may play a significant role.
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3
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Antimony resistance in leishmania, focusing on experimental research. J Trop Med 2011; 2011:695382. [PMID: 22174724 PMCID: PMC3235892 DOI: 10.1155/2011/695382] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2011] [Revised: 08/24/2011] [Accepted: 09/05/2011] [Indexed: 12/02/2022] Open
Abstract
Leishmaniases are parasitic diseases that spread in many countries with a prevalence of 12 million cases. There are few available treatments and antimonials are still of major importance in the therapeutic strategies used in most endemic regions. However, resistance toward these compounds has recently emerged in areas where the replacement of these drugs is mainly limited by the cost of alternative molecules. In this paper, we reviewed the studies carried out on antimonial resistance in Leishmania. Several common limitations of these works are presented before prevalent approaches to evidence antimonial resistance are related. Afterwards, phenotypic determination of resistance is described, then confronted to clinical outcome. Finally, we detail molecular mechanisms and targets involved in resistance and already identified in vitro within selected mutant strains or in clinical isolates.
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4
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Abstract
The emergence of drug resistance in protozoan parasites is a major obstacle to their control. Since vaccines are not yet in sight for several of these parasites, there is on urgent need to develop new and better drugs. These antimicrobial agents will possibly be more expensive, and will therefore impose on additional burden in health-care costs and in the planning of public health policies of the developing countries. A better understanding of drug resistance, to try to circumvent or overcome it, and the search for new specific cellular targets of parasites are warranted. The development, in vitro, of drug-resistant parasite cell lines has been instrumental in our understanding of the mechanisms of drug resistance in parasitic protozoans. Marc Ouellette and Barbara Popodopoulou here present on overview of the recent progress on the elucidation of mechanisms of drug resistance in the protozoan parasite Leishmania, selected under laboratory conditions.
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Affiliation(s)
- M Ouellette
- Service d'Infectiologie du Centre de Recherche du CHUL, 2705 Boulevard Laurier, Sointe-Fay, Québec, Canada GIV 4G2
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5
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Kitchin KT. Recent advances in arsenic carcinogenesis: modes of action, animal model systems, and methylated arsenic metabolites. Toxicol Appl Pharmacol 2001; 172:249-61. [PMID: 11312654 DOI: 10.1006/taap.2001.9157] [Citation(s) in RCA: 489] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Recent advances in our knowledge of arsenic carcinogenesis include the development of rat or mouse models for all human organs in which inorganic arsenic is known to cause cancer-skin, lung, urinary bladder, liver, and kidney. Tumors can be produced from either promotion of carcinogenesis protocols (mouse skin and lungs, rat bladder, kidney, liver, and thyroid) or from complete carcinogenesis protocols (rat bladder and mouse lung). Experiments with p53(+/-) and K6/ODC transgenic mice administered dimethylarsinic acid or arsenite have shown some degree of carcinogenic, cocarcinogenic, or promotional activity in skin or bladder. At present, with the possible exception of skin, the arsenic carcinogenesis models in wild-type animals are more highly developed than in transgenic mice. Recent advances in arsenic metabolism have suggested that methylation of inorganic arsenic may be a toxification, rather than a detoxification, pathway and that trivalent methylated arsenic metabolites, particularly monomethylarsonous acid and dimethylarsinous acid, have a great deal of biological activity. Accumulating evidence indicates that these trivalent, methylated, and relatively less ionizable arsenic metabolites may be unusually capable of interacting with cellular targets such as proteins and even DNA. In risk assessment of environmental arsenic, it is important to know and to utilize both the mode of carcinogenic action and the shape of the dose-response curve at low environmental arsenic concentrations. Although much progress has been recently made in the area of arsenic's possible mode(s) of carcinogenic action, a scientific concensus has not yet been reached. In this review, nine different possible modes of action of arsenic carcinogenesis are presented and discussed-induced chromosomal abnormalities, oxidative stress, altered DNA repair, altered DNA methylation patterns, altered growth factors, enhanced cell proliferation, promotion/progression, gene amplification, and suppression of p53.
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Affiliation(s)
- K T Kitchin
- Environmental Carcinogenesis Division, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, 27711, USA
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6
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Huang RN, Lee TC. Arsenite efflux is inhibited by verapamil, cyclosporin A, and GSH-depletingagents in arsenite-resistant chinese hamster ovary cells. Toxicol Appl Pharmacol 1996. [DOI: 10.1016/s0041-008x(96)80004-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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7
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Affiliation(s)
- A K Cruz
- Departamento de Bioquímica, Faculdade de Medicina de Ribeirao Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
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8
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Olmo A, Arrebola R, Bernier V, González-Pacanowska D, Ruiz-Pérez LM. Co-existence of circular and multiple linear amplicons in methotrexate-resistant Leishmania. Nucleic Acids Res 1995; 23:2856-64. [PMID: 7659507 PMCID: PMC307122 DOI: 10.1093/nar/23.15.2856] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Circular and linear amplicons were analyzed in detail in Leishmania tropica cells resistant to methotrexate (MTX). Both types of elements presented sequences related to the H locus and coexisted in resistant cells. The linear amplicons appeared first during the selection process (at 10 microM MTX) and varied with regard to size and structure in cells exposed to increasing concentrations of drug. The circular element was evident at higher concentrations (50 microMs) but was the major amplified DNA in cells resistant to 1000 microM MTX while the level of amplification of the linear elements remained low. The extrachromosomal DNAs were unstable in the absence of drug and their disappearance coincided with an increase in sensitivity to MTX. Mapping of the minichromosomes and the circular element showed that they were all constituted by inverted duplications. The circular amplicon contained an inverted repeat derived from the H locus that encompassed the pteridine reductase gene (PTR1) responsible for MTX resistance. The amplified segment in the linear amplicons was longer and included the pgpB and pgpC genes that encode P-glycoproteins of unknown function previously characterized in different Leishmania species.
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Affiliation(s)
- A Olmo
- Instituto de Parasitología y Biomedicina, Consejo Superior de Investigaciones Científicas, Granada, Spain
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9
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Abstract
Drug resistance has emerged as a devasting impediment to the treatment and control of diseases of parasitic origin. The underlying mechanisms that contribute to this drug resistance in field isolates, however, are poorly understood. Members of the P-glycoprotein gene (pgp) family have been identified, cloned, and sequenced in Plasmodia, Leishmania, and Entamoeba, and variations in pgp copy number and/or expression have been implicated as a basis for drug resistance in each of these genera. The spectrum of drugs to which parasitic protozoa containing amplified pgp genes and/or transcripts are refractory range from a phenotype similar to that observed with multidrug-resistant mammalian cells to those that are completely distinct. The availability of molecular probes to pgp genes provides valuable reagents to dissect the role of pgp gene amplification and overexpression in mediating drug resistance in parasitic protozoa and to determine the physiological function of P-glycoproteins in this clinically consequential group of human pathogens.
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Affiliation(s)
- B Ullman
- Department of Biochemistry and Molecular Biology, Oregon Health Sciences University, Portland 97201-3098, USA
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10
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Abstract
Arsenic ions, frequently present as environmental pollutants, are very toxic for most microorganisms. Some microbial strains possess genetic determinants that confer resistance. In bacteria, these determinants are often found on plasmids, which has facilitated their study at the molecular level. Bacterial plasmids conferring arsenic resistance encode specific efflux pumps able to extrude arsenic from the cell cytoplasm thus lowering the intracellular concentration of the toxic ions. In Gram-negative bacteria, the efflux pump consists of a two-component ATPase complex. ArsA is the ATPase subunit and is associated with an integral membrane subunit, ArsB. Arsenate is enzymatically reduced to arsenite (the substrate of ArsB and the activator of ArsA) by the small cytoplasmic ArsC polypeptide. In Gram-positive bacteria, comparable arsB and arsC genes (and proteins) are found, but arsA is missing. In addition to the wide spread plasmid arsenic resistance determinant, a few bacteria confer resistance to arsenite with a separate determinant for enzymatic oxidation of more-toxic arsenite to less-toxic arsenate. In contrast to the detailed information on the mechanisms of arsenic resistance in bacteria, little work has been reported on this subject in algae and fungi.
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Affiliation(s)
- C Cervantes
- Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana, Mich., Mexico
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11
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Chiquero MJ, Olmo A, Navarro P, Ruiz-Perez LM, Castanys S, Gonzalez-Pacanowska D, Gamarro F. Amplification of the H locus in Leishmania infantum. BIOCHIMICA ET BIOPHYSICA ACTA 1994; 1227:188-94. [PMID: 7986827 DOI: 10.1016/0925-4439(94)90094-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We have selected for a Leishmania infantum cell line resistant to high levels of methotrexate (MTX). The resulting cells were 1233-fold more resistant than wild-type and contained amplified H-region circles. Homologous genes to the antifolate resistant ltdh gene and to the P-glycoprotein ltpgpA gene of Leishmania tarentolae were observed to be contained within the amplicon. In order to invoke additional mechanisms of resistance, we examined possible variations in MTX accumulation. Resistance was not correlated with a decreased uptake of MTX. On the contrary, the resistant line presented a 3-fold increase in the steady-state accumulation of drug with regard to the wild-type line. Northern blot analysis using gene specific probes, showed that the ltdh probe and the ltpgpA probe recognized single transcripts of 1 kb and 5 kb respectively which were both overexpressed only approx. 5-fold in resistant cells. We propose that amplification of the antifolate resistance gene, homologue to the ltdh gene of L. tarentolae, is apparently the only mechanism involved in resistance to the cytotoxic drug MTX in L. infantum resistant to 1000 microM of MTX.
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Affiliation(s)
- M J Chiquero
- Instituto de Parasitologá y Biomedicina, Consejo Superior de Investigaciones Científicas, Granada,Spain
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12
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Singh AK, Liu HY, Lee ST. Atomic absorption spectrophotometric measurement of intracellular arsenite in arsenite-resistant Leishmania. Mol Biochem Parasitol 1994; 66:161-4. [PMID: 7984181 DOI: 10.1016/0166-6851(94)90049-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- A K Singh
- Division of Infectious Diseases, Academia Sinica, Taipei, Taiwan
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13
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Myler PJ, Lodes MJ, Merlin G, de Vos T, Stuart KD. An amplified DNA element in Leishmania encodes potential integral membrane and nucleotide-binding proteins. Mol Biochem Parasitol 1994; 66:11-20. [PMID: 7984172 DOI: 10.1016/0166-6851(94)90031-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
LD1 is a 27.5-kb sequence that occurs in an approx. 2.2-Mb chromosome in all species and strains of Leishmania. In Leishmania infantum MHOM/BL/67/ITMAP263, LD1 is also present as an inverted dimeric repeat in multicopy, 55-kb circular molecules. Sequence analysis of a 7873-nt segment derived from the circular DNA reveals 4 open reading frames (ORFs) with potential protein coding function. One ORF predicts a protein with an ATP/GTP binding site motif. Another ORF predicts a protein with 10-12 potential membrane-spanning domains, suggesting that it encodes an integral membrane protein. This protein also has homology with that predicted by the ESAG10 gene of Trypanosoma brucei.
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Affiliation(s)
- P J Myler
- Seattle Biomedical Research Institute, WA 98109-1651
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14
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Gamarro F, Chiquero MJ, Amador MV, Légaré D, Ouellette M, Castanys S. P-glycoprotein overexpression in methotrexate-resistant Leishmania tropica. Biochem Pharmacol 1994; 47:1939-47. [PMID: 7912069 DOI: 10.1016/0006-2952(94)90067-1] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A methotrexate (MTX)-resistant Leishmania tropica line develops a stable drug-resistant phenotype in which the resistance mechanism is associated with a significant reduction in MTX accumulation. After a 2 hr exposure to [3H]MTX, a L. tropica line resistant to 1000 microM of MTX did not accumulate more than 3% of the amount of drug incorporated by wild-type cells. The same resistant cell line was found to be cross-resistant to several unrelated drugs. The monoclonal antibody C219, directed against the cytoplasmic domain of mammalian P-glycoproteins, recognized a putative P-glycoprotein of 240 kDa overexpressed in the resistant line. Also, this resistant line showed the overexpression of the putative homolog of the ltpgpE gene, as determined by northern blot analysis using gene-specific probes for the P-glycoprotein genes of Leishmania tarentolae. This overexpression was not correlated with a proportional increase in the copy number of the gene, but Southern blot analysis suggested that the ltpgpE homolog was overexpressed as a consequence of gene rearrangement. This would be considered as an epiphenomenon that probably does not arise from the same MTX-resistant mechanism.
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Affiliation(s)
- F Gamarro
- Instituto de Parasitología y Biomedicina Lopez-Neyra, Consejo Superior de Investigaciones Científicas, Granada, Spain
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15
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Isolation and characterization of a mutant dihydrofolate reductase-thymidylate synthase from methotrexate-resistant Leishmania cells. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)34100-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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16
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Segovia M. Leishmania gene amplification: a mechanism of drug resistance. ANNALS OF TROPICAL MEDICINE AND PARASITOLOGY 1994; 88:123-30. [PMID: 8067807 DOI: 10.1080/00034983.1994.11812849] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Leishmania spp. are excellent models for analysing the mechanisms of drug resistance, one of the major barriers to the treatment and control of several major diseases. They may become refractory to drugs as the result of gene amplification. Amplified Leishmania DNA are extrachromosomal, usually circular, and arise from a source chromosome. Several multicopy extrachromosomal DNA have been identified, either spontaneously in unselected stocks or, more commonly, in response to multiple rounds of step-wise increases in drug concentration. R circles, G circles and ODC140-L minichromosomes are extrachromosomal amplifications encoding copies of dihydrofolate reductase-thymidylate synthase, glycosyltransferase, and ornithine decarboxylase, respectively, and conferring resistance to inhibitors of these gene products (methotrexate, tunicamycin and alpha-difluoromethylornithine, respectively). Another DNA amplification, named the H circle, has been detected in response to several unrelated drugs and confers drug resistance. Leishmania spp. represent a unique model since, even without drug pressure, gene amplifications appear and remain as extrachromosomal circular and linear amplicons. The CD1/LD1 elements, of unknown biological role, arise de novo in cultures in the absence of drug pressure.
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Affiliation(s)
- M Segovia
- Departamento de Genética y Microbiología, Facultad de Medicina, Universidad de Murcia, Spain
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17
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Abstract
Evidence for the phenomenon of multiple drug resistance (MDR) in the well studied pathogenic protozoa has been examined. This has been placed in the more familiar context of the MDR efflux transporters and the cloned mdr genes of mammalian cells. Homologues of the mdr gene family in protozoa and their possible role in drug efflux have been compared with their mammalian counterparts. Possible mechanisms and models for drug efflux have been considered. The unusual and extensive range of substrates transported by the ATP-binding cassette (ABC) family of transporters which includes the MDRs has been raised. The impact of kinetics, structure and bioenergetics of the MDR family members on mechanisms of transport has been accentuated to argue that MDR efflux considered in isolation appears bizarre but may be better understood in a broader context.
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Affiliation(s)
- P Upcroft
- Queensland Institute of Medical Research, Bancroft Centre, Brisbane, Australia
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18
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Grondin K, Papadopoulou B, Ouellette M. Homologous recombination between direct repeat sequences yields P-glycoprotein containing amplicons in arsenite resistant Leishmania. Nucleic Acids Res 1993; 21:1895-901. [PMID: 8098523 PMCID: PMC309430 DOI: 10.1093/nar/21.8.1895] [Citation(s) in RCA: 83] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The protozoan parasite Leishmania often responds to drug pressure by amplifying part of its genome. At least two loci derived from the same 800 kb chromosome were amplified either as extrachromosomal circles or linear fragments after sodium arsenite selection. A 50 kb linear amplicon was detected in six independent arsenite mutants and revertants grown in absence of arsenite rapidly lost the amplicon and part of their resistance. The circular extrachromosomal amplicons, all derived from the H locus of Leishmania, were characterized more extensively. In all cases, direct repeated sequences appeared to be involved in the formation of circular amplicons. Most amplicons were generated after homologous recombination between two linked P-glycoprotein genes. This recombination event was, in two cases, associated with the loss of one allele of the chromosomal copy. A novel rearrangement point was found in a mutant where the amplicon was created by recombination between two 541 bp direct repeats surrounding the P-glycoprotein gene present at the H locus. It is also at one of these repeats that an H circle with large inverted duplications was formed. We propose that the presence of repeated sequences in the H locus facilitates the amplification of the drug resistance genes concentrated in this locus.
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Affiliation(s)
- K Grondin
- Service d'Infectiologie du Centre de Recherche du CHUL, Québec, Canada
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19
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Wilson K, Beverley SM, Ullman B. Stable amplification of a linear extrachromosomal DNA in mycophenolic acid-resistant Leishmania donovani. Mol Biochem Parasitol 1992; 55:197-206. [PMID: 1359409 DOI: 10.1016/0166-6851(92)90140-f] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Pulsed field gel electrophoretic analysis of chromosomes of MPA100 cells, a strain of Leishmania donovani that possesses an approx. 15-fold amplified IMP dehydrogenase (IMPDH) gene copy number, revealed a new 280-kb extrachromosomal DNA, IMPDH-280, that was not present in wild type parental cells. Southern blots of these pulsed field gels revealed that the vast majority of the amplified impdh genes were localized on IMPDH-280. In addition to the 700-kb wild type chromosome, the impdh probe also recognized a 740-kb chromosome in the MPA100 genome. The pulse time-dependent relative mobility of IMPDH-280 in pulsed field gels, the failure of limited gamma-irradiation to generate a new discrete DNA fragment, and the susceptibility of IMPDH-280 to lambda-exonuclease digestion, demonstrated that IMPDH-280 was a linear molecule. IMPDH-280 was also recognized by a telomere probe but not by fragments derived from amplified DNAs found in other drug-resistant Leishmania. IMPDH-280 and the drug resistance phenotype remained stable when MPA100 cells were propagated in the absence of drug for 2 years. The appearance of IMPDH-280 in MPA100 cells represents one of the first examples of an amplification of a linear extrachromosomal DNA element mediating drug resistance in Leishmania and the first instance of a linear DNA amplification that is stable in the absence of selective pressure.
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Affiliation(s)
- K Wilson
- Department of Biochemistry and Molecular Biology, Oregon Health Sciences University, Portland 97201-3098
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20
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Callahan H, Beverley S. A member of the aldoketo reductase family confers methotrexate resistance in Leishmania. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(18)35743-0] [Citation(s) in RCA: 78] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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21
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Tripp CA, Wisdom WA, Myler PJ, Stuart KD. A multicopy, extrachromosomal DNA in Leishmania infantum contains two inverted repeats of the 27.5-kilobase LD1 sequence and encodes numerous transcripts. Mol Biochem Parasitol 1992; 55:39-50. [PMID: 1435875 DOI: 10.1016/0166-6851(92)90125-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Leishmania DNA 1 (LD1) is a 27.5-kb sequence that occurs as an inverted repeat in a 55-kb multicopy, circular DNA in Leishmania infantum ITMAP263. The sequence is also found with a different genomic organization, possibly a tandem array, within a 1.5-Mb chromosome in all Leishmania isolates. About 26 stable transcripts of LD1 sequence, ranging from 0.6 to 15 kb, are found in ITMAP263. Transcripts were detected from both strands of the entire LD1 sequence, but the inverted repeat nature of the circular molecule prevented determination of whether transcription proceeded in one or both directions. Nine abundant transcripts (0.6-8.4 kb) from adjacent regions on the same strand of the repeat unit may represent mature mRNAs. One of these transcripts was shown to contain the 39-nucleotide spliced leader sequence characteristic of the 5' termini of trypanosomatid mRNAs. Several transcripts from the other strand of the repeat unit are also abundant and contain sequence complementary to some of the putative mRNAs. Less abundant, larger transcripts that span sequences encoding abundant mRNAs are also present, suggesting that transcription of LD1 is polycistronic.
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MESH Headings
- Animals
- Blotting, Northern
- Centrifugation, Isopycnic
- Cloning, Molecular
- DNA Probes
- DNA, Circular/chemistry
- DNA, Protozoan/chemistry
- DNA, Superhelical/chemistry
- Deoxyribonuclease EcoRI
- Electrophoresis, Agar Gel
- Leishmania donovani/genetics
- Nucleic Acid Hybridization
- RNA, Messenger/genetics
- RNA, Protozoan/genetics
- Repetitive Sequences, Nucleic Acid
- Restriction Mapping
- Transcription, Genetic
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Affiliation(s)
- C A Tripp
- Seattle Biomedical Research Institute, WA 98109-1651
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22
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Fairlamb AH, Carter NS, Cunningham M, Smith K. Characterisation of melarsen-resistant Trypanosoma brucei brucei with respect to cross-resistance to other drugs and trypanothione metabolism. Mol Biochem Parasitol 1992; 53:213-22. [PMID: 1501641 DOI: 10.1016/0166-6851(92)90023-d] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
An arsenical resistant cloned line of Trypanosoma brucei brucei was derived from a parent sensitive clone by repeated selection in vivo with the pentavalent melaminophenyl arsenical, sodium melarsen. The melarsen-resistant line was tested in vivo in mice against a range of trypanocidal compounds and found to be cross-resistant to the trivalent arsenicals, melarsen oxide, melarsoprol and trimelarsen (33, 67 and 122-fold, respectively). A similar pattern of cross-resistance was found in vitro using a spectrophotometric lysis assay (greater than 200-fold resistance to melarsen oxide and greater than 20-fold resistance to both trimelarsen and melarsoprol). Both lines were equally sensitive to lysis by the lipophilic analogue phenylarsine oxide in vitro, suggesting that the melamine moiety is involved in the resistance mechanism. Although trypanothione has been reported to be the primary target for trivalent arsenical drugs [1], levels of trypanothione and glutathione were not significantly different between the resistant and sensitive lines. Statistically significant differences were found in the levels of trypanothione reductase (50% lower in the resistant clone) and dihydrolipoamide dehydrogenase (38% higher in the resistant clone). However, the Km for trypanothione disulphide, the Ki for the competitive inhibitor Mel T (the melarsen oxide adduct with trypanothione) and the pseudo-first order inactivation rates with melarsen oxide were the same for trypanothione reductase purified from both clones. The melarsen-resistant line also showed varying degrees of cross-resistance to the diamidines: stilbamidine (38-fold), berenil (31.5-fold), propamidine (5.7-fold) and pentamidine (1.5-fold). Cross-resistance correlates with the maximum interatomic distance between the amidine groups of these drugs and suggests that the diamidines and melaminophenyl arsenicals are recognised by the same transport system.
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Affiliation(s)
- A H Fairlamb
- Department of Medical Parasitology, London School of Hygiene and Tropical Medicine, UK
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23
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Multidrug resistance in Leishmania donovani is conferred by amplification of a gene homologous to the mammalian mdr1 gene. Mol Cell Biol 1992. [PMID: 1350325 DOI: 10.1128/mcb.12.6.2855] [Citation(s) in RCA: 99] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Drug resistance is a major impediment to the effective treatment of parasitic diseases. The role of multidrug resistance (mdr) genes and their products in this drug resistance phenomenon, however, remains controversial. In order to determine whether mdr gene amplification and overexpression can be connected to a multidrug resistance phenotype in parasitic protozoa, a mutant strain of Leishmania donovani was generated by virtue of its ability to proliferate in medium containing increasing concentrations of vinblastine. The vinblastine-resistant strain, VINB1000, displayed a cross-resistance to puromycin and the anthracyclines, a growth phenotype that could be attributed to an impaired ability to accumulate the toxic drugs. By using the polymerase chain reaction, two different DNA fragments, LEMDR06 and LEMDRF2, were amplified from leishmanial genomic DNA, and each amplified fragment encoded a product that was significantly homologous to parts of the mammalian P-glycoprotein. In the VINB1000 strain, the mdr gene recognized by the LEMDR06 probe was amplified approximately 50-fold in copy number, whereas the mdr genes that hybridized to LEMDRF2 or to a fragment of the previously characterized ltpgpA gene were not amplified. Moreover, the VINB1000 cell line expressed a LEMDR06 gene transcript of 12.5 kb in size that was not detected in the parental wild-type strain. To furnish a functional test for mdr gene amplification and expression in L. donovani, the L. donovani gene recognized by the LEMDR06 polymerase chain reaction product, ldmdr1, was isolated from a genomic library, transfected into wild-type cells, and amplified over 500-fold by selection in 0.5 mg of G418 per ml. The resulting transfectants were resistant to all drugs to which VINB1000 cells were resistant and sensitive to all drugs to which VINB1000 cells were sensitive. These studies demonstrate that amplification of the ldmdr1 gene either by direct selection or subsequent to transfection can confer a drug-resistant phenotype in parasitic protozoa similar to that observed for MDR mammalian cells.
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24
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Henderson DM, Sifri CD, Rodgers M, Wirth DF, Hendrickson N, Ullman B. Multidrug resistance in Leishmania donovani is conferred by amplification of a gene homologous to the mammalian mdr1 gene. Mol Cell Biol 1992; 12:2855-65. [PMID: 1350325 PMCID: PMC364480 DOI: 10.1128/mcb.12.6.2855-2865.1992] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Drug resistance is a major impediment to the effective treatment of parasitic diseases. The role of multidrug resistance (mdr) genes and their products in this drug resistance phenomenon, however, remains controversial. In order to determine whether mdr gene amplification and overexpression can be connected to a multidrug resistance phenotype in parasitic protozoa, a mutant strain of Leishmania donovani was generated by virtue of its ability to proliferate in medium containing increasing concentrations of vinblastine. The vinblastine-resistant strain, VINB1000, displayed a cross-resistance to puromycin and the anthracyclines, a growth phenotype that could be attributed to an impaired ability to accumulate the toxic drugs. By using the polymerase chain reaction, two different DNA fragments, LEMDR06 and LEMDRF2, were amplified from leishmanial genomic DNA, and each amplified fragment encoded a product that was significantly homologous to parts of the mammalian P-glycoprotein. In the VINB1000 strain, the mdr gene recognized by the LEMDR06 probe was amplified approximately 50-fold in copy number, whereas the mdr genes that hybridized to LEMDRF2 or to a fragment of the previously characterized ltpgpA gene were not amplified. Moreover, the VINB1000 cell line expressed a LEMDR06 gene transcript of 12.5 kb in size that was not detected in the parental wild-type strain. To furnish a functional test for mdr gene amplification and expression in L. donovani, the L. donovani gene recognized by the LEMDR06 polymerase chain reaction product, ldmdr1, was isolated from a genomic library, transfected into wild-type cells, and amplified over 500-fold by selection in 0.5 mg of G418 per ml. The resulting transfectants were resistant to all drugs to which VINB1000 cells were resistant and sensitive to all drugs to which VINB1000 cells were sensitive. These studies demonstrate that amplification of the ldmdr1 gene either by direct selection or subsequent to transfection can confer a drug-resistant phenotype in parasitic protozoa similar to that observed for MDR mammalian cells.
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Affiliation(s)
- D M Henderson
- Department of Biochemistry and Molecular Biology, Oregon Health Sciences University, Portland 97201-3098
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25
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Lee SY, Lee ST, Chang KP. Transkinetoplastidy--a novel phenomenon involving bulk alterations of mitochondrion-kinetoplast DNA of a trypanosomatid protozoan. ACTA ACUST UNITED AC 1992; 39:190-6. [PMID: 1348540 DOI: 10.1111/j.1550-7408.1992.tb01300.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Dramatic and consistent changes of mitochondria or kinetoplast DNA (kDNA) were observed in certain variants of Leishmania amazonensis (A variants) selected in vitro for arsenite-resistance. This was found initially by comparing different lots of wild-type cells and their respective A variants resistant to 30 microM arsenite. The kDNAs isolated from these two groups had different restriction patterns and hybridized poorly to each other, whereas those from different lots within each of the two groups were identical. Hybridization data showed an overall identity of less than 10(-3) between total kDNAs of the two groups. This difference was further examined in three independent series of variants, which were selected from three different clones for resistance to graded concentrations of arsenite (5-50 microM). In all three series, their kDNAs were found to change abruptly in an identical pattern at a late step of the selection process, i.e., A variants resistant to 15 microM or 30 microM arsenite. There was no apparent loss of kDNA in the process. Most of the changes observed appear to involve a shift in either the dominance or the copy number of different minicircle subclasses. Surprisingly, the kDNAs of tunicamycin-resistant variants (T variants) were also found to undergo similar changes. Genetic changes previously described in both A and T variants are limited to their nuclei. Namely, different chromosomal regions are amplified to produce large DNA circles which are responsible for the drug-resistant phenotypes. Interestingly, other arsenite-resistant clones without such chromosomal DNA amplification (A' variants) had kDNA of the wild-type pattern. The profound changes of kDNA observed are unprecedented. We propose the term "transkinetoplastidy" for this phenomenon to distinguish it from dyskinetoplastidy or the loss of kDNA described previously in trypanosomatid protozoa. This phenomenon is discussed with respect to the possible mechanisms of its generation, regulation and relation to the drug-resistant phenotypes.
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Affiliation(s)
- S Y Lee
- Laboratory of Molecular Parasitology, Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
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26
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Hanson S, Adelman J, Ullman B. Amplification and molecular cloning of the ornithine decarboxylase gene of Leishmania donovani. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(18)45885-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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27
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Abstract
Cancer epidemiology has identified several metal compounds as human carcinogens. Recent evidence suggests that carcinogenic metals induce genotoxicity in a multiplicity of ways, either alone or by enhancing the effects of other agents. This review summarizes current information on the genotoxicity of arsenic, chromium, nickel, beryllium and cadmium compounds and their possible roles in carcinogenesis. Each of these metals is distinct in its primary modes of action; yet there are several mechanisms induced by more than one metal, including: the induction of cellular immunity and oxidative stress, the inhibition of DNA metabolism and repair and the formation of DNA- and/or protein-crosslinks.
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Affiliation(s)
- E T Snow
- Nelson Institute of Environmental Medicine, New York University Medical Center, Tuxedo 10987
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28
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Tripp CA, Myler PJ, Stuart K. A DNA sequence (LD1) which occurs in several genomic organizations in Leishmania. Mol Biochem Parasitol 1991; 47:151-6. [PMID: 1682806 DOI: 10.1016/0166-6851(91)90174-5] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Leishmania DNA 1 (LD1) is a 27.5-kb sequence that occurs in all 91 stocks of twelve New and Old World Leishmania species examined; related sequences are present in some other kinetoplastid species. LD1 has no homology to several DNA sequences that are amplified in drug-resistant Leishmania. LD1 occurs in 3 different genomic organizations in Leishmania, depending on the stock. It is present within large (1.5-2 megabase) chromosomes in all stocks, and 74 stocks contain only this form. In 12 other stocks, LD1 also occurs in smaller (less than 550 kb) chromosomes, some of which are multicopy. Five stocks contain LD1 in multicopy circular DNA molecules in addition to the sequences found in the larger chromosome(s). Restriction fragment length polymorphisms of LD1 sequences correlate with taxonomic grouping, suggsting that LD1 is an endogenous sequence.
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Affiliation(s)
- C A Tripp
- Seattle Biomedical Research Institute, WA 98109-1651
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29
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Ouellette M, Borst P. Drug resistance and P-glycoprotein gene amplification in the protozoan parasite Leishmania. Res Microbiol 1991; 142:737-46. [PMID: 1961984 DOI: 10.1016/0923-2508(91)90089-s] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Amplification of the H circle is often associated with methotrexate (MTX) selection in Leishmania species. We have shown that the H circle of Leishmania tarentolae contains an open reading frame, ItpgpA, that has the attributes of P-glycoproteins (large plasma membrane proteins known to extrude lipophilic drugs from mammalian cells). H region amplification was also noted in some mutants selected for resistance to arsenite and vinblastine. Mutants having the complete 68-kb circles were cross-resistant to MTX, but two arsenite mutants having only part of the H region amplified, but including ItpgpA, were not cross-resistant to MTX. These results suggest that the putative determinant for MTX resistance present on the H circle is not ItpgpA. We have also determined how ItpgpA-containing plasmids were generated from the chromosomal copy. The H circle contains a 30-kb inverted duplication separated by two unique DNA segments. The corresponding H region of chromosomal DNA has only one copy of the duplicated DNA. We have shown that the two unique segments in chromosomal DNA are flanked by inverted repeats suggesting that H circles could be formed by a foldback mechanism (see fig. 2). Unexpectedly, a plasmid present in cells selected for arsenite resistance lacked part of the H region and the long inverted repeats. It appears to have been formed by intrachromosomal recombination between two P-glycoprotein genes, ItpgpA and ItpgpB, located adjacent to the H region. Our results show that under drug pressure, the same P-glycoprotein-encoding region in Leishmania may be amplified by very different mechanisms and yield different amplicons.
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Affiliation(s)
- M Ouellette
- Service d'Infectiologie, CHUL, Québec, Canada
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30
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Katakura K, Peng Y, Pithawalla R, Detke S, Chang KP. Tunicamycin-resistant variants from five species of Leishmania contain amplified DNA in extrachromosomal circles of different sizes with a transcriptionally active homologous region. Mol Biochem Parasitol 1991; 44:233-43. [PMID: 1646959 DOI: 10.1016/0166-6851(91)90009-u] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Twelve independent variants were selected from five species of Leishmania for resistance to tunicamycin by exposure of cultured promastigotes to increasing concentrations of this antibiotic, an inhibitor of the microsomal N-acetylglucosamine-1-phosphate transferase in the dolichol pathway of N-glycosylation. All variants obtained from all species, as found previously with Leishmania amazonensis, contain amplified chromosomal DNA exclusively as extrachromosomal circles. These circular amplicons hybridize with amplified DNAs cloned previously from tunicamycin-resistant Leishmania amazonensis, but not with those from Leishmania resistant to other drugs. The amplicons from tunicamycin-resistant cells vary with different species in size from 30 to 70 kb, but all share a homologous region of 20 kb. Multiple independent transcripts are overexpressed from this region. Elevation of the microsomal glycosyltransferase activity is demonstrated in these variants from representative species. The results thus provide further evidence that this enzyme is overexpressed due to amplification of the gene in these cells. The consistent observation of this event in all cases studied also suggests that this is the predominant, if not the only mechanism of tunicamycin resistance in Leishmania.
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Affiliation(s)
- K Katakura
- Department of Microbiology and Immunology, University of Health Sciences, Chicago Medical School, IL 60064
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31
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Wilson K, Collart FR, Huberman E, Stringer JR, Ullman B. Amplification and molecular cloning of the IMP dehydrogenase gene of Leishmania donovani. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)52346-2] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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32
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Ellenberger TE, Beverley SM. Multiple Drug Resistance and Conservative Amplification of the H Region in Leishmania major. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(18)63816-5] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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