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Lamba S, Roy A. Demystifying the potential of inhibitors targeting DNA topoisomerases in unicellular protozoan parasites. Drug Discov Today 2023; 28:103574. [PMID: 37003515 DOI: 10.1016/j.drudis.2023.103574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 03/09/2023] [Accepted: 03/25/2023] [Indexed: 04/01/2023]
Abstract
DNA topoisomerases are a group of enzymes omnipresent in all organisms. They maintain the DNA topology during replication, repair, recombination, and transcription. However, the structure of topoisomerase in protozoan parasites differs significantly from that of human topoisomerases; thus, this enzyme acts as a crucial target in drug development against parasitic diseases. Although the therapeutic potential of drugs targeting the parasitic topoisomerase is well known, to manage the shortcomings of currently available therapeutics and the emergence of drug resistance, the discovery of novel antiparasitic molecules is an urgent need. In this review, we describe various investigational and repurposed topoisomerase inhibitors developed against protozoan parasites over the past few years. Teaser: Fatal parasitic diseases are an increasing cause for concern; here, we provide a compilation of different inhibitors targeting DNA topoisomerases, enzymes that are essential for, and unique to, protozoan parasites; therefore, inhibitors are efficient and have few adverse effects.
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Affiliation(s)
- Swati Lamba
- Department of Biotechnology, Savitribai Phule Pune University, Ganeshkhind Road, Pune 411007, India
| | - Amit Roy
- Department of Biotechnology, Savitribai Phule Pune University, Ganeshkhind Road, Pune 411007, India.
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Capel E, Luis-Barrera J, Sorazu A, Uria U, Prieto L, Reyes E, Carrillo L, Vicario JL. Transannular Approach to 2,3-Dihydropyrrolo[1,2- b]isoquinolin-5(1 H)-ones through Brønsted Acid-Catalyzed Amidohalogenation. J Org Chem 2022; 87:10062-10072. [PMID: 35880953 PMCID: PMC9361296 DOI: 10.1021/acs.joc.2c01045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
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A transannular approach has been developed for the construction
of pyrrolo[1,2-b]isoquinolinones starting from benzo-fused
nine-membered enelactams. This process takes place in the presence
of a halogenating agent and under Brønsted acid catalysis and
proceeds via a transannular amidohalogenation, followed by elimination.
The reaction has been found to be wide in scope, enabling the formation
of a variety of tricyclic products in good overall yield, regardless
of the substitution pattern in the initial lactam substrate. The reaction
has also been applied to the total synthesis of a reported topoisomerase
I inhibitor and to the formal synthesis of rosettacin. Further extension
of this methodology allows the preparation of 10-iodopyrrolo[1,2-b]isoquinolinones by using an excess of halogenating agent
and these compounds can be further manipulated through standard Suzuki
coupling chemistry into a variety of 10-aryl-substituted pyrrolo[1,2-b]isoquinolinones.
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Affiliation(s)
- Estefanía Capel
- Department of Organic and Inorganic Chemistry, University of the Basque Country (UPV/EHU), P.O. Box 644, 48080 Bilbao, Spain
| | - Javier Luis-Barrera
- Department of Organic and Inorganic Chemistry, University of the Basque Country (UPV/EHU), P.O. Box 644, 48080 Bilbao, Spain
| | - Ana Sorazu
- Department of Organic and Inorganic Chemistry, University of the Basque Country (UPV/EHU), P.O. Box 644, 48080 Bilbao, Spain
| | - Uxue Uria
- Department of Organic and Inorganic Chemistry, University of the Basque Country (UPV/EHU), P.O. Box 644, 48080 Bilbao, Spain
| | - Liher Prieto
- Department of Organic and Inorganic Chemistry, University of the Basque Country (UPV/EHU), P.O. Box 644, 48080 Bilbao, Spain
| | - Efraím Reyes
- Department of Organic and Inorganic Chemistry, University of the Basque Country (UPV/EHU), P.O. Box 644, 48080 Bilbao, Spain
| | - Luisa Carrillo
- Department of Organic and Inorganic Chemistry, University of the Basque Country (UPV/EHU), P.O. Box 644, 48080 Bilbao, Spain
| | - Jose L Vicario
- Department of Organic and Inorganic Chemistry, University of the Basque Country (UPV/EHU), P.O. Box 644, 48080 Bilbao, Spain
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Cinelli MA. Topoisomerase 1B poisons: Over a half-century of drug leads, clinical candidates, and serendipitous discoveries. Med Res Rev 2018; 39:1294-1337. [PMID: 30456874 DOI: 10.1002/med.21546] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2018] [Revised: 10/08/2018] [Accepted: 10/09/2018] [Indexed: 12/17/2022]
Abstract
Topoisomerases are DNA processing enzymes that relieve supercoiling (torsional strain) in DNA, are necessary for normal cellular division, and act by nicking (and then religating) DNA strands. Type 1B topoisomerase (Top1) is overexpressed in certain tumors, and the enzyme has been extensively investigated as a target for cancer chemotherapy. Various chemical agents can act as "poisons" of the enzyme's religation step, leading to Top1-DNA lesions, DNA breakage, and eventual cellular death. In this review, agents that poison Top1 (and have thus been investigated for their anticancer properties) are surveyed, including natural products (such as camptothecins and indolocarbazoles), semisynthetic camptothecin and luotonin derivatives, and synthetic compounds (such as benzonaphthyridines, aromathecins, and indenoisoquinolines), as well as targeted therapies and conjugates. Top1 has also been investigated as a therapeutic target in certain viral and parasitic infections, as well as autoimmune, inflammatory, and neurological disorders, and a summary of literature describing alternative indications is also provided. This review should provide both a reference for the medicinal chemist and potentially offer clues to aid in the development of new Top1 poisons.
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Affiliation(s)
- Maris A Cinelli
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan
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Activity of Aromathecins against African Trypanosomes. Antimicrob Agents Chemother 2018; 62:AAC.00786-18. [PMID: 30104277 DOI: 10.1128/aac.00786-18] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 07/05/2018] [Indexed: 11/20/2022] Open
Abstract
African sleeping sickness is responsible for thousands of deaths annually, and new therapeutics are needed. This study evaluated aromathecins, experimental inhibitors of mammalian topoisomerase IB, against Trypanosoma brucei African trypanosomes. The compounds had selectively toxic antiparasitic potency, in situ poisoning activity against the phylogenetically unique topoisomerase in these parasites, and a representative compound intercalated into DNA with micromolar affinity. DNA intercalation and topoisomerase poisoning may contribute to the antitrypanosomal activity of aromathecins.
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Abstract
AbstractThe protozoan parasiteLeishmaniais endemic in large parts of the world which causes leishmaniasis. Its visceral form is fatal if not treated and is caused mostly byLeishmania donovani,Leishmania infantumandLeishmania chagasi. Given the difficulties linked to vector (sandfly) control and the lack of an effective vaccine, the control of leishmaniasis relies mostly on chemotherapy. Unfortunately, the prevalence of parasites becoming resistant to the first-line drug pentavalent antimony (SbV) is increasing worldwide. Few alternative drugs are available that includes amphotericin B, pentamidine and miltefosine (oral). Already, decreases in efficacy, resistance and toxicity have been noted against these drugs. Dry antileishmanial pipeline further indicates the slow pace of drug discovery in this field where resistance as a major barrier. Full understanding of the genetic and molecular basis of the parasite is lagging. Since leishmaniasis is a neglected disease and occurs predominantly in the developing world largely, therefore, it is unaddressed. The pharma industry argues that development of the new drug is too costly and risky to invest in low return neglected diseases is very high. Research is also needed to identify new and effective drug targets. The lack of drug research and development for neglected diseases will require some new strategies. We have discussed the various cause of slow pace of antileishmanial drug discovery in this review to pay attention of researchers and also take the public and private initiative to make the process fast for new antileishmanial drug development.
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Khan MOF. Trypanothione Reductase: A Viable Chemotherapeutic Target for Antitrypanosomal and Antileishmanial Drug Design. Drug Target Insights 2017. [DOI: 10.1177/117739280700200007] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Affiliation(s)
- M. Omar F. Khan
- College of Pharmacy, Southwestern Oklahoma State University, 100 Campus Drive, Weatherford, OK 73096, U.S.A
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Liu YQ, Li WQ, Morris-Natschke SL, Qian K, Yang L, Zhu GX, Wu XB, Chen AL, Zhang SY, Nan X, Lee KH. Perspectives on biologically active camptothecin derivatives. Med Res Rev 2015; 35:753-89. [PMID: 25808858 DOI: 10.1002/med.21342] [Citation(s) in RCA: 127] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Camptothecins (CPTs) are cytotoxic natural alkaloids that specifically target DNA topoisomerase I. Research on CPTs has undergone a significant evolution from the initial discovery of CPT in the late 1960s through the study of synthetic small-molecule derivatives to investigation of macromolecular constructs and formulations. Over the past years, intensive medicinal chemistry efforts have generated numerous CPT derivatives. Three derivatives, topotecan, irinotecan, and belotecan, are currently prescribed as anticancer drugs, and several related compounds are now in clinical trials. Interest in other biological effects, besides anticancer activity, of CPTs is also growing exponentially, as indicated by the large number of publications on the subject during the last decades. Therefore, the main focus of the present review is to provide an ample but condensed overview on various biological activities of CPT derivatives, in addition to continued up-to-date coverage of anticancer effects.
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Affiliation(s)
- Ying-Qian Liu
- School of Pharmacy, Lanzhou University, Lanzhou 730000, P. R. China.,Provincial Engineering Laboratory of Biopesticide Preparation, Zhejiang A&F University, Lin'an 311300, P. R. China
| | - Wen-Qun Li
- School of Pharmacy, Lanzhou University, Lanzhou 730000, P. R. China
| | - Susan L Morris-Natschke
- Natural Products Research Laboratories, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, 27599
| | - Keduo Qian
- Natural Products Research Laboratories, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, 27599
| | - Liu Yang
- Environmental and Municipal Engineering School, Lanzhou Jiaotong University, Lanzhou, 730000, P. R. China
| | - Gao-Xiang Zhu
- School of Pharmacy, Lanzhou University, Lanzhou 730000, P. R. China
| | - Xiao-Bing Wu
- School of Pharmacy, Lanzhou University, Lanzhou 730000, P. R. China
| | - An-Liang Chen
- Provincial Engineering Laboratory of Biopesticide Preparation, Zhejiang A&F University, Lin'an 311300, P. R. China
| | - Shao-Yong Zhang
- Provincial Engineering Laboratory of Biopesticide Preparation, Zhejiang A&F University, Lin'an 311300, P. R. China
| | - Xiang Nan
- School of Pharmacy, Lanzhou University, Lanzhou 730000, P. R. China
| | - Kuo-Hsiung Lee
- Natural Products Research Laboratories, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, 27599.,Chinese Medicine Research and Development Center, China Medical University Hospital, Taichung, 40447, Taiwan
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Sangshetti JN, Kalam Khan FA, Kulkarni AA, Arote R, Patil RH. Antileishmanial drug discovery: comprehensive review of the last 10 years. RSC Adv 2015. [DOI: 10.1039/c5ra02669e] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
This review covers the current aspects of leishmaniasis including marketed drugs, new antileishmanial agents, and possible drug targets of antileishmanial agents.
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Affiliation(s)
| | | | | | - Rohidas Arote
- Department of Molecular Genetics
- School of Dentistry
- Seoul National University
- Seoul
- Republic of Korea
| | - Rajendra H. Patil
- Department of Biotechnology
- Savitribai Phule Pune University
- Pune 411007
- India
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Smirlis D, Soares MBP. Selection of molecular targets for drug development against trypanosomatids. Subcell Biochem 2014; 74:43-76. [PMID: 24264240 DOI: 10.1007/978-94-007-7305-9_2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Trypanosomatid parasites are a group of flagellated protozoa that includes the genera Leishmania and Trypanosoma, which are the causative agents of diseases (leishmaniases, sleeping sickness and Chagas disease) that cause considerable morbidity and mortality, affecting more than 27 million people worldwide. Today no effective vaccines for the prevention of these diseases exist, whereas current chemotherapy is ineffective, mainly due to toxic side effects of current drugs and to the emergence of drug resistance and lack of cost effectiveness. For these reasons, rational drug design and the search of good candidate drug targets is of prime importance. The search for drug targets requires a multidisciplinary approach. To this end, the completion of the genome project of many trypanosomatid species gives a vast amount of new information that can be exploited for the identification of good drug candidates with a prediction of "druggability" and divergence from mammalian host proteins. In addition, an important aspect in the search for good drug targets is the "target identification" and evaluation in a biological pathway, as well as the essentiality of the gene in the mammalian stage of the parasite, which is provided by basic research and genetic and proteomic approaches. In this chapter we will discuss how these bioinformatic tools and experimental evaluations can be integrated for the selection of candidate drug targets, and give examples of metabolic and signaling pathways in the parasitic protozoa that can be exploited for rational drug design.
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Vlachakis D, Pavlopoulou A, Roubelakis MG, Feidakis C, Anagnou NP, Kossida S. 3D molecular modeling and evolutionary study of the Trypanosoma brucei DNA Topoisomerase IB, as a new emerging pharmacological target. Genomics 2014; 103:107-13. [DOI: 10.1016/j.ygeno.2013.11.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Revised: 09/19/2013] [Accepted: 11/29/2013] [Indexed: 10/25/2022]
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Jones AJ, Avery VM. Whole-organism high-throughput screening against Trypanosoma brucei brucei. Expert Opin Drug Discov 2013; 8:495-507. [PMID: 23540598 DOI: 10.1517/17460441.2013.783816] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION Human African trypanosomiasis (HAT) occurs as a result of infection with the protozoan parasites Trypanosoma brucei gambiense and T.b. rhodesiense and is nearly always fatal without treatment. However, current therapeutic options are severely limited and there is a desperate need for new compounds to treat the disease. Whole-cell high-throughput screening (HTS) is a technique frequently used to identify compounds with trypanocidal activity. AREAS COVERED The authors examine the development of whole-organism HTS assays for T.b. brucei. The authors describe the successes achieved through HTS and discuss the advantages and disadvantages of whole-organism HTS. EXPERT OPINION Despite hundreds of trypanocidal molecules being identified by whole-organism HTS, very few have progressed into preclinical development. The failure of molecules identified by HTS to progress along the drug development pathway is due to a multitude of factors including undrug-like molecules and molecules having poor pharmacodynamics/kinetic properties. Future studies should focus on screening libraries that contain drug-like molecules that possess some of the properties required in the final compound.
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Affiliation(s)
- Amy J Jones
- Discovery Biology, Eskitis Institute (N27), Griffith University, Brisbane, 4111, Australia
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A pentapeptide signature motif plays a pivotal role in Leishmania DNA topoisomerase IB activity and camptothecin sensitivity. Biochim Biophys Acta Gen Subj 2012; 1820:2062-71. [DOI: 10.1016/j.bbagen.2012.09.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2012] [Revised: 09/03/2012] [Accepted: 09/07/2012] [Indexed: 01/07/2023]
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Mariod AA, Abdelwahab SI. Sclerocarya birrea(Marula), An African Tree of Nutritional and Medicinal Uses: A Review. FOOD REVIEWS INTERNATIONAL 2012. [DOI: 10.1080/87559129.2012.660716] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Li Z, Li X, Cao Z, Xu Y, Lin H, Zhao Y, Wei Y, Qian Z. Camptothecin nanocolloids based on N,N,N-trimethyl chitosan: efficient suppression of growth of multiple myeloma in a murine model. Oncol Rep 2012; 27:1035-40. [PMID: 22245938 PMCID: PMC3583474 DOI: 10.3892/or.2012.1635] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Accepted: 12/19/2011] [Indexed: 01/08/2023] Open
Abstract
Camptothecin (CPT) exhibits very strong antitumor effects by inhibiting the activity of DNA topoisomerase I, but its application is greatly limited due to its low solubility and the instability of the active lactone form. To overcome these shortcomings, in the present study, we prepared novel camptothecin nanocolloids based on N,N,N-trimethyl chitosan (CPT-TMC) to efficiently and safely administer CPT systemically. Herein, we investigated the antitumor activity of CPT-TMC against a murine Balb/c myeloma model. Our results showed that CPT-TMC more effectively inhibited tumor growth and prolonged survival time than CPT in vivo, but no statistical difference was observed in vitro between CPT-TMC and CPT. These findings suggest that N,N,N-trimethyl chitosan could increase the stability and the antitumor effect of CPT and CPT-TMC is a potential approach for the effective treatment of multiple myeloma.
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Affiliation(s)
- Zhengguang Li
- Department of Oncology, The Third Affiliated Hospital of Soochow University, Changzhou 213003, PR China
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Effect of topoisomerase inhibitors and DNA-binding drugs on the cell proliferation and ultrastructure of Trypanosoma cruzi. Int J Antimicrob Agents 2011; 37:449-56. [DOI: 10.1016/j.ijantimicag.2010.11.031] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2010] [Revised: 10/31/2010] [Accepted: 11/01/2010] [Indexed: 11/22/2022]
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Chawla B, Madhubala R. Drug targets in Leishmania. J Parasit Dis 2010; 34:1-13. [PMID: 21526026 DOI: 10.1007/s12639-010-0006-3] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2010] [Accepted: 06/22/2010] [Indexed: 02/03/2023] Open
Abstract
Leishmaniasis is a major public health problem and till date there are no effective vaccines available. The control strategy relies solely on chemotherapy of the infected people. However, the present repertoire of drugs is limited and increasing resistance towards them has posed a major concern. The first step in drug discovery is to identify a suitable drug target. The genome sequences of Leishmania major and Leishmania infantum has revealed immense amount of information and has given the opportunity to identify novel drug targets that are unique to these parasites. Utilization of this information in order to come up with a candidate drug molecule requires combining all the technology and using a multi-disciplinary approach, right from characterizing the target protein to high throughput screening of compounds. Leishmania belonging to the order kinetoplastidae emerges from the ancient eukaryotic lineages. They are quite diverse from their mammalian hosts and there are several cellular processes that we are getting to know of, which exist distinctly in these parasites. In this review, we discuss some of the metabolic pathways that are essential and could be used as potential drug targets in Leishmania.
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Affiliation(s)
- Bhavna Chawla
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067 India
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Shah A, Diculescu VC, Qureshi R, Oliveira-Brett AM. Electrochemical reduction mechanism of camptothecin at glassy carbon electrode. Bioelectrochemistry 2010; 79:173-8. [DOI: 10.1016/j.bioelechem.2010.03.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2009] [Revised: 03/02/2010] [Accepted: 03/08/2010] [Indexed: 10/19/2022]
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Affiliation(s)
- Rajeshwar P. Verma
- Department of Chemistry, Pomona College, 645 North College Avenue, Claremont, California 91711
| | - Corwin Hansch
- Department of Chemistry, Pomona College, 645 North College Avenue, Claremont, California 91711
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Abstract
African trypanosomiasis (sleeping sickness), caused by protozoan Trypanosoma brucei species, is a debilitating disease that is lethal if untreated. Available drugs are antiquated, toxic, and compromised by emerging resistance. The indenoisoquinolines are a class of noncamptothecin topoisomerase IB poisons that are under development as anticancer agents. We tested a variety of indenoisoquinolines for their ability to kill T. brucei. Indenoisoquinolines proved trypanocidal at submicromolar concentrations in vitro. Structure-activity analysis yielded motifs that enhanced potency, including alkylamino substitutions on N-6, methoxy groups on C-2 and C-3, and a methylenedioxy bridge between C-8 and C-9. Detailed analysis of eight water-soluble indenoisoquinolines demonstrated that in trypanosomes the compounds inhibited DNA synthesis and acted as topoisomerase poisons. Testing these compounds on L1210 mouse leukemia cells revealed that all eight were more effective against trypanosomes than against mammalian cells. In preliminary in vivo experiments one compound delayed parasitemia and extended survival in mice subjected to a lethal trypanosome challenge. The indenoisoquinolines provide a promising lead for the development of drugs against sleeping sickness.
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Das BB, Ganguly A, Majumder HK. DNA Topoisomerases of Leishmania: The Potential Targets for Anti-Leishmanial Therapy. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2008; 625:103-15. [DOI: 10.1007/978-0-387-77570-8_9] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Lavaggi ML, Aguirre G, Boiani L, Orelli L, García B, Cerecetto H, González M. Pyrimido[1,2-a]quinoxaline 6-oxide and phenazine 5,10-dioxide derivatives and related compounds as growth inhibitors of Trypanosoma cruzi. Eur J Med Chem 2008; 43:1737-41. [DOI: 10.1016/j.ejmech.2007.10.031] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2007] [Revised: 10/23/2007] [Accepted: 10/24/2007] [Indexed: 10/22/2022]
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Balaña-Fouce R, Redondo CM, Pérez-Pertejo Y, Díaz-González R, Reguera RM. Targeting atypical trypanosomatid DNA topoisomerase I. Drug Discov Today 2006; 11:733-40. [PMID: 16846801 DOI: 10.1016/j.drudis.2006.06.014] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2005] [Revised: 04/21/2006] [Accepted: 06/16/2006] [Indexed: 11/26/2022]
Abstract
Tropical diseases produced by kinetoplastid protozoa are among humanity's costliest banes, owing to high mortality and the economic burden resulting from morbidity. Drug resistant strains of parasites, together with insecticide-resistant vectors, are contributing to their increased prevalence in the developing world. Their extension now threatens industrialized countries because of opportunistic infections in immuno-compromised individuals. Current chemotherapy is expensive, has undesirable side effects and, in many patients, is only marginally effective. Based on the clinical success of camptothecin derivatives as anticancer agents, DNA topoisomerases have been identified as targets for drug development. The substantial differences in homology between trypanosome and leishmania DNA topoisomerase IB compared with the human form provides a new lead in the study of the structural determinants that can be targeted.
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Affiliation(s)
- Rafael Balaña-Fouce
- Department of Pharmacology and Toxicology, University of León, Campus de Vegazana s/n 24071 León, Spain.
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Abstract
Trypanosomes are the causative agents of Chagas' disease in Central and South America and sleeping sickness in sub-Saharan Africa. The current chemotherapy of the human trypanosomiases relies on only six drugs, five of which were developed > 30 years ago. In addition, these drugs display undesirable toxic side effects and the emergence of drug-resistant trypanosomes has been reported. Therefore, the development of new drugs in the treatment of Chagas' disease and sleeping sickness is urgently required. This article summarises the recent progress in identifying novel lead compounds for antitrypanosomal chemotherapy. Particular emphasis is placed on those agents showing promising, selective antitrypanosomal activity.
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Affiliation(s)
- Dietmar Steverding
- School of Medicine, Health Policy and Practice, University of East Anglia, Norwich NR4 TJ7, UK.
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Reguera RM, Redondo CM, Gutierrez de Prado R, Pérez-Pertejo Y, Balaña-Fouce R. DNA topoisomerase I from parasitic protozoa: A potential target for chemotherapy. ACTA ACUST UNITED AC 2006; 1759:117-31. [PMID: 16757380 DOI: 10.1016/j.bbaexp.2006.03.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2006] [Revised: 03/22/2006] [Accepted: 03/30/2006] [Indexed: 11/28/2022]
Abstract
The growing occurrence of drug resistant strains of unicellular prokaryotic parasites, along with insecticide-resistant vectors, are the factors contributing to the increased prevalence of tropical diseases in underdeveloped and developing countries, where they are endemic. Malaria, cryptosporidiosis, African and American trypanosomiasis and leishmaniasis threaten human beings, both for the high mortality rates involved and the economic loss resulting from morbidity. Due to the fact that effective immunoprophylaxis is not available at present; preventive sanitary measures and pharmacological approaches are the only sources to control the undesirable effects of such diseases. Current anti-parasitic chemotherapy is expensive, has undesirable side effects or, in many patients, is only marginally effective. Under this point of view molecular biology techniques and drug discovery must walk together in order to find new targets for chemotherapy intervention. The identification of DNA topoisomerases as a promising drug target is based on the clinical success of camptothecin derivatives as anticancer agents. The recent detection of substantial differences between trypanosome and leishmania DNA topoisomerase IB with respect to their homologues in mammals has provided a new lead in the study of the structural determinants that can be effectively targeted. The present report is an up to date review of the new findings on type IB DNA topoisomerase in unicellular parasites and the role of these enzymes as targets for therapeutic agents.
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Affiliation(s)
- R M Reguera
- Dpto. Farmacología y Toxicología (INTOXCAL), Universidad de León, Campus de Vegazana s/n, 24071 León, Spain
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25
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Davies DR, Mushtaq A, Interthal H, Champoux JJ, Hol WGJ. The structure of the transition state of the heterodimeric topoisomerase I of Leishmania donovani as a vanadate complex with nicked DNA. J Mol Biol 2006; 357:1202-10. [PMID: 16487540 DOI: 10.1016/j.jmb.2006.01.022] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2005] [Revised: 12/29/2005] [Accepted: 01/03/2006] [Indexed: 10/25/2022]
Abstract
Type IB topoisomerases are essential enzymes that are responsible for relaxing superhelical tension in DNA by forming a transient covalent nick in one strand of the DNA duplex. Topoisomerase I is a target for anti-cancer drugs such as camptothecin, and these drugs also target the topoisomerases I in pathogenic trypanosomes including Leishmania species and Trypanosoma brucei. Most eukaryotic enzymes, including human topoisomerase I, are monomeric. However, for Leishmania donovani, the DNA-binding activity and the majority of residues involved in catalysis are located in a large subunit, designated TOP1L, whereas the catalytic tyrosine residue responsible for covalent attachment to DNA is located in a smaller subunit, called TOP1S. Here, we present the 2.27A crystal structure of an active truncated L.donovani TOP1L/TOP1S heterodimer bound to nicked double-stranded DNA captured as a vanadate complex. The vanadate forms covalent linkages between the catalytic tyrosine residue of the small subunit and the nicked ends of the scissile DNA strand, mimicking the previously unseen transition state of the topoisomerase I catalytic cycle. This structure fills a critical gap in the existing ensemble of topoisomerase I structures and provides crucial insights into the catalytic mechanism.
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Affiliation(s)
- Douglas R Davies
- Department of Biochemistry, Box 357742, University of Washington, Seattle, WA 98195-7742, USA
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26
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Effective loading and controlled release of camptothecin by O-carboxymethylchitosan aggregates. Carbohydr Polym 2006. [DOI: 10.1016/j.carbpol.2005.08.006] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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27
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Sriram D, Yogeeswari P, Thirumurugan R, Bal TR. Camptothecin and its analogues: a review on their chemotherapeutic potential. Nat Prod Res 2005; 19:393-412. [PMID: 15938148 DOI: 10.1080/14786410412331299005] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Topoisomerase I (Topo-I) is a major target for anticancer drug discovery and design. As a result, Topo-I inhibitors constitute an important class of the current anticancer drugs. To date, all of the Topo-I inhibitors that have been clinically evaluated are analogues of camptothecin (CPT), an extract of the Chinese tree Camptotheca acuminata. CPT has shown significant antitumor activity to lung, ovarian, breast, pancreas and stomach cancers. In this article the, phytochemical aspect, and various structural modifications are comprehensively reviewed as in rings A, B, C, D and E. Biological activity of camptothecin, other than anticancer, reported till the year 2003 has also been discussed.
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Affiliation(s)
- Dharmarajan Sriram
- Medicinal Chemistry Research Laboratory, Pharmacy Group, Birla Institute of Technology and Science, Pilani 333 031, India.
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28
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Deterding A, Dungey FA, Thompson KA, Steverding D. Anti-trypanosomal activities of DNA topoisomerase inhibitors. Acta Trop 2005; 93:311-6. [PMID: 15715983 DOI: 10.1016/j.actatropica.2005.01.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2004] [Revised: 01/07/2005] [Accepted: 01/12/2005] [Indexed: 11/24/2022]
Abstract
Only four drugs are available for chemotherapy of human African sleeping sickness with undesirable toxic side effects. The development of new anti-trypanosomal drugs is, therefore, urgently required. In this study, 15 DNA topoisomerase inhibitors, including approved anti-cancer drugs, were tested for in vitro activity against bloodstream forms of Trypanosoma brucei and human leukaemia HL-60 cells. All compounds exhibited anti-trypanosomal activity, with ED50 values ranging between 3 nM and 30 microM, and MIC values between 100 nM and >100 microM. The trypanocidal activities of the most effective DNA topoisomerase inhibitors, aclarubicin, doxorubicin and mitoxantrone, were comparable with those of commercial anti-trypanosomal drugs. These data support the use of DNA topoisomerase inhibitors as lead compounds for anti-trypanosomal drug development.
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Affiliation(s)
- Alexander Deterding
- School of Biological Sciences, University of Bristol, Woodland Road, Bristol BS8 1UG, United Kingdom
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29
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Bakshi RP, Shapiro TA. RNA interference of Trypanosoma brucei topoisomerase IB: both subunits are essential. Mol Biochem Parasitol 2004; 136:249-55. [PMID: 15478803 DOI: 10.1016/j.molbiopara.2004.04.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Type IB topoisomerases are enzymes essential for the orderly synthesis of nucleic acids and are the molecular target for antitumor camptothecins. In dozens of organisms, including eukaryotes, bacteria, and viruses, this enzyme is monomeric. However, we previously found that topoisomerase IB in trypanosomes is a heteromultimer, comprised of two distinct subunits encoded by separate genes. A large 90 kDa subunit contains the DNA binding domain and a small 36 kDa subunit contains the catalytic domain. In this study we use RNA interference to silence each of the subunits separately. For each subunit, tetracycline-induced expression of double-stranded RNA results in drastic reduction of cognate mRNA and protein. For the large subunit, nucleic acid biosynthesis (as monitored by the incorporation of radiolabeled precursors into DNA and RNA) is halved by 39 h, and cell growth halts by 72 h, after induction. The steady state level of both nuclear and mitochondrial mRNAs is reduced. Virtually identical results are obtained by silencing the small subunit. Interestingly, although interference is specific at the level of mRNA, silencing of one subunit leads to a profound reduction in the level of protein for both subunits, suggesting that survival, or perhaps synthesis, of each subunit depends upon the presence of the other. These findings underscore the essential nature of type IB topoisomerase activity in Trypanosoma brucei and its suitability as a target for rational drug design.
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Affiliation(s)
- Rahul P Bakshi
- Division of Clinical Pharmacology, Department of Medicine, Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, MD 21205, USA
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30
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Das A, Dasgupta A, Sengupta T, Majumder HK. Topoisomerases of kinetoplastid parasites as potential chemotherapeutic targets. Trends Parasitol 2004; 20:381-7. [PMID: 15246322 DOI: 10.1016/j.pt.2004.06.005] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The protozoan parasites Trypanosoma, Leishmania and Crithidia, which belong to the order kinetoplastidae, emerge from the most ancient eukaryotic lineages. The diversity found in the life cycle of these organisms must be directed by genetic events, wherein topoisomerases play an important role in cellular processes affecting the topology and organization of intracellular DNA. Topoisomerases are valuable as potential drug targets because they have indispensable function in cell biology. This review summarizes what is known about topoisomerase genes and proteins of kinetoplastid parasites and the roles of these enzymes as targets for therapeutic agents.
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Affiliation(s)
- Aditi Das
- Sealy Center for Molecular Sciences, University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA
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31
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Nenortas E, Kulikowicz T, Burri C, Shapiro TA. Antitrypanosomal activities of fluoroquinolones with pyrrolidinyl substitutions. Antimicrob Agents Chemother 2003; 47:3015-7. [PMID: 12937017 PMCID: PMC182618 DOI: 10.1128/aac.47.9.3015-3017.2003] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Fluoroquinolones with pyrrolidinyl substitutions were tested against Trypanosoma brucei and mammalian cells. Bulky substituents at C-7 or a 1-2-bridging thiazolidine ring increased antitrypanosomal activity and selective toxicity. These compounds trap protein-DNA complexes and inhibit nucleic acid biosynthesis in trypanosomes, characteristics of topoisomerase II inhibition.
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Affiliation(s)
- Elizabeth Nenortas
- Departments of Medicine and of Pharmacology and Molecular Sciences, The Johns Hopkins University, Baltimore, Maryland 21205, USA
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32
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Bodley AL, Chakraborty AK, Xie S, Burri C, Shapiro TA. An unusual type IB topoisomerase from African trypanosomes. Proc Natl Acad Sci U S A 2003; 100:7539-44. [PMID: 12810956 PMCID: PMC164622 DOI: 10.1073/pnas.1330762100] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
African trypanosomes are ancient eukaryotes that cause lethal disease in humans and cattle. Available drugs are inadequate and the need for new therapeutic targets is great. Trypanosoma brucei and related pathogens differ strikingly from higher eukaryotes in many aspects of nucleic acid structure and metabolism. We find yet another example of this in their unusual DNA topoisomerase IB. Type IB topoisomerases relieve the supercoils that accumulate during DNA and RNA synthesis, and are of considerable importance as the target for antitumor camptothecins. Dozens of type IB topoisomerases sequenced from eukaryotes, bacteria, and pox viruses are all encoded by a single gene that predictably contains a highly conserved DNA binding domain and C-terminal catalytic domain, linked by a nonconserved hydrophilic region. We find that topoisomerase IB in T. brucei is encoded by two genes: one for the DNA-binding domain and a second for the C-terminal catalytic domain. In keeping with this, highly purified fractions of native T. brucei topoisomerase IB catalytic activity contain two proteins, of 90 and 36 kDa. The native enzyme is conventional in its Mg2+-independence, ability to relax positive and negative supercoils, and inhibition by camptothecin. Camptothecin promotes the formation of a covalent complex between 32P-labeled substrate DNA and the small subunit. This unusual structural organization may provide a missing link in the evolution of type IB enzymes, which are thought to have arisen over time from the fusion of two independent domains. It also provides another basis for the design of selectively toxic drug candidates.
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Affiliation(s)
- Annette L Bodley
- Division of Clinical Pharmacology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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33
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Scovill J, Blank E, Konnick M, Nenortas E, Shapiro T. Antitrypanosomal activities of tryptanthrins. Antimicrob Agents Chemother 2002; 46:882-3. [PMID: 11850279 PMCID: PMC127471 DOI: 10.1128/aac.46.3.882-883.2002] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
New drugs and molecular targets are needed against Trypanosoma brucei, the protozoan that causes African sleeping sickness. Tryptanthrin (indolo[2,1-b]quinazoline-6,12-dione), a traditional antifungal agent, and 11 analogs were tested against T. brucei in vitro. The greatest activity was conferred by electron-withdrawing groups in the 8 position of the tryptanthrin ring system; the most potent compound had a 50% effective concentration of 0.40 microM.
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Affiliation(s)
- John Scovill
- Department of Chemistry, Bucknell University, Lewisburg, Pennsylvania 17837, USA
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34
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Atawodi SE, Ameh DA, Ibrahim S, Andrew JN, Nzelibe HC, Onyike EO, Anigo KM, Abu EA, James DB, Njoku GC, Sallau AB. Indigenous knowledge system for treatment of trypanosomiasis in Kaduna state of Nigeria. JOURNAL OF ETHNOPHARMACOLOGY 2002; 79:279-282. [PMID: 11801393 DOI: 10.1016/s0378-8741(01)00351-8] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A survey was carried out in Kaduna State of Nigeria to establish the indigenous knowledge system for treating trypanosomiasis in domestic animals. Questionnaire and interviews were, respectively, administered to, or conducted with about 200 livestock farmers and traders spread around the state. Data obtained revealed the use of several plants either alone or in combination, for the treatment and management of trypasonomiasis. The most common plants encountered were Adansonia digitata, Terminalia avicennoides, Khaya senegalensis, Cissus populnea, Tamarindus indica, Lawsonia inermis, Boswellia dalzielli, Pseudocedrela kotschi, Syzyium quinensis, Sterculia setigera, Afzelia africana, Prosopis africana, Lancea kerstingii. The method of preparation and mode of administration of some of these plants in the treatment of trypanosomiasis are reviewed and discussed.
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Affiliation(s)
- S E Atawodi
- Department of Biochemistry, Ahmadu Bello University, Zaria, Nigeria.
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35
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Keiser J, Stich A, Burri C. New drugs for the treatment of human African trypanosomiasis: research and development. Trends Parasitol 2001; 17:42-9. [PMID: 11137740 DOI: 10.1016/s1471-4922(00)01829-8] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Chemotherapy of human African trypanosomiasis is problematic because of the high frequency of severe adverse events, the long duration and high cost of treatment, and an increasing number of treatment-refractory cases. New cost-efficient, easy-to-use drugs are urgently needed. Whereas basic research on potential drug targets is anchored in academia, the complex, highly regulated and very expensive process of preclinical and clinical drug development is almost exclusively in the hands of pharmaceutical companies. Jennifer Keiser, August Stich and Christian Burri here review, from the angle of industrial drug research and development, the past ten years of research activities at different stages of the development of trypanocidal drugs, and assess future prospects. The absence of compounds in clinical development Phases I-III indicates no new drugs will become available in the next few years.
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Affiliation(s)
- J Keiser
- Swiss Tropical Institute, PO Box, CH-4002, Basel, Switzerland
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36
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Abstract
Protozoan parasites are responsible for a wide range of debilitating and fatal diseases that are proving notoriously difficult to treat. Many of the standard chemotherapies in use today are expensive, have toxic side effects and, in some cases have marginal efficacy because of the emergence of drug-resistant parasites. In the search for more effective treatments, protozoan topoisomerases are now being considered as potential drug targets, building on the clinical success of anticancer and antibacterial agents that target human and bacterial topoisomerases. In this review, Sandra Cheesman explores progress in this relatively new but potentially important field of research.
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Affiliation(s)
- S J Cheesman
- Institute of Cell and Molecular Biology, the University of Edinburgh, Darwin Building, King's Buildings, Mayfield Road, Edinburgh, UK EH9 3JR.
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37
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Werbovetz KA, Bhattacharjee AK, Brendle JJ, Scovill JP. Analysis of stereoelectronic properties of camptothecin analogues in relation to biological activity. Bioorg Med Chem 2000; 8:1741-7. [PMID: 10976522 DOI: 10.1016/s0968-0896(00)00111-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Camptothecin and four of its 10,11-methylenedioxy analogues were examined for their activity against the pathogenic protozoan Leishmania donovani in vitro. The methylenedioxy analogues were 36- to 180-fold more potent than the parent camptothecin, possessing IC50 values ranging from 160 to 32 nM against the parasite. Our finding that the methylenedioxy camptothecins possess greater activity than camptothecin, which is also the case for other cell types and for the generation of cleavable complex in the presence of DNA and purified mammalian topoisomerase I, prompted us to examine the molecular features of camptothecin and methylenedioxy camptothecin analogues. A delocalization of positive potential was observed in the methylenedioxy camptothecin analogues, which could increase the affinity of these molecules for DNA. In addition, geometrical and electronic differences between the E ring of camptothecin and its methylenedioxy analogues were noted. One or both of these factors may contribute to the superior biological activity of the methylenedioxy camptothecin analogues.
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Affiliation(s)
- K A Werbovetz
- Department of Parasitologv, Walter Reed Army Institute of Research, Washington, DC 20307-5100, USA.
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38
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Nenortas E, Burri C, Shapiro TA. Antitrypanosomal activity of fluoroquinolones. Antimicrob Agents Chemother 1999; 43:2066-8. [PMID: 10428939 PMCID: PMC89417 DOI: 10.1128/aac.43.8.2066] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Six fluoroquinolones presently in clinical use and four investigational tetracyclic fluoroquinolones were tested for in vitro activity against bloodstream-form Trypanosoma brucei brucei. All compounds had measurable activity, but the tetracyclic analogs were most potent, with 50% effective concentrations in the low micromolar range. In general, trypanosomes were more susceptible than L1210 leukemia cells. Consistent with the notion that they target type II topoisomerase in trypanosomes, the fluoroquinolones promote the formation of protein-DNA covalent complexes.
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Affiliation(s)
- E Nenortas
- Division of Clinical Pharmacology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205-2185, USA
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39
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Liposomes, micelles and microemulsions as new delivery systems for cytotoxic alkaloids. PHARMACEUTICAL SCIENCE & TECHNOLOGY TODAY 1999; 2:288-298. [PMID: 10407392 DOI: 10.1016/s1461-5347(99)00171-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
This review describes the design and performance of specialized delivery systems, such as liposomes, micellar solutions and microemulsions, for the administration of cytotoxic alkaloids. Special attention is directed towards three types of compound, Vinca, Camptotheca and Taxus alkaloids, which have been previously indicated as of promise as antitumour agents but which still present serious drawbacks. In this respect, this review analyses different delivery strategies that are able to substantially improve the therapeutic applicability of such antitumour drugs.
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40
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Broccoli S, Marquis JF, Papadopoulou B, Olivier M, Drolet M. Characterization of a Leishmania donovani gene encoding a protein that closely resembles a type IB topoisomerase. Nucleic Acids Res 1999; 27:2745-52. [PMID: 10373592 PMCID: PMC148484 DOI: 10.1093/nar/27.13.2745] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
In order to clone the gene encoding a type I DNA topoisomerase from Leishmania donovani, a PCR-amplified DNA fragment obtained with degenerate oligodeoxyribonucleotides was used to screen a genomic library from this parasite. An open reading frame of 1905 bases encoding a putative protein of 635 amino acid residues was isolated. A substantial part of the protein shares a significant degree of homology with the sequence of other known members of the IB topoisomerase family, in a highly conserved region of these enzymes termed the core domain. However, homology is completely lost after this conserved central core. Moreover, no conventional active tyrosine site could be identified. In fact, the protein expressed in Escherichia coli did not show any relaxation activity in vitro and was unable to complement a mutant deficient in topoisomerase I activity. The results of Southern blot experiments strongly suggested that the cloned gene was not a pseudogene. Northern analysis revealed that the gene was transcribed in its full length and also excluded the possibility that some form of splicing is necessary to produce a mature messenger. Furthermore, our results indicate that the gene is preferentially expressed in actively growing L.donovani promastigotes and that it is also expressed in other kinetoplastid parasites.
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Affiliation(s)
- S Broccoli
- Département de Microbiologie et Immunologie, Université de Montréal, CP 6128, Succursale Centre-Ville, Montréal, Québec H3C 3J7, Canada and
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41
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Tosh K, Cheesman S, Horrocks P, Kilbey B. Plasmodium falciparum: stage-related expression of topoisomerase I. Exp Parasitol 1999; 91:126-32. [PMID: 9990340 DOI: 10.1006/expr.1998.4362] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The expression and activity of topoisomerase I (PfTopoI) has been examined during the intraerythrocytic stages of the Plasmodium falciparum life cycle. The promoter is inactive during the early ring stage and becomes active only during the later trophozoite and schizont stages. The PfTOP1 transcript starts to accumulate in the trophozoite stage parasite, decreasing again in the schizont stage. Using both stage-specific Western analysis and immunofluorescent assays we show that PfTopoI is present at low levels in rings and accumulates to approximately equal levels in the trophozoite and schizont stages. Experiments to determine the activity of PfTopoI, using a topoisomerase I relaxation assay, show that there is a low level of PfTopoI activity in both ring and trophozoite stages, but activity increases dramatically in the schizont stage. The PfTopoI activity can be inhibited by treatment with specific antiserum and by the type I topoisomerase-specific inhibitor camptothecin.
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MESH Headings
- Animals
- Antibodies, Protozoan/chemistry
- Blotting, Northern
- Blotting, Western
- Camptothecin/pharmacology
- DNA Topoisomerases, Type I/genetics
- DNA Topoisomerases, Type I/metabolism
- DNA, Protozoan/chemistry
- Electrophoresis, Agar Gel
- Electrophoresis, Polyacrylamide Gel
- Enzyme Inhibitors/pharmacology
- Fluorescent Antibody Technique
- Gene Expression Regulation, Enzymologic
- Malaria, Falciparum/enzymology
- Malaria, Falciparum/parasitology
- Nucleic Acid Hybridization
- Plasmodium falciparum/drug effects
- Plasmodium falciparum/enzymology
- Plasmodium falciparum/genetics
- Promoter Regions, Genetic/physiology
- Rabbits
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Affiliation(s)
- K Tosh
- Institute of Cell and Molecular Biology, University of Edinburgh, United Kingdom
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42
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Ray S, Hazra B, Mittra B, Das A, Majumder HK. Diospyrin, a bisnaphthoquinone: a novel inhibitor of type I DNA topoisomerase of Leishmania donovani. Mol Pharmacol 1998; 54:994-9. [PMID: 9855627 DOI: 10.1124/mol.54.6.994] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Diospyrin is a plant product that has significant inhibitory effect on the growth of Leishmania donovani promastigotes. This compound inhibits the catalytic activity of DNA topoisomerase I of the parasite. Like camptothecin, it induces topoisomerase I mediated DNA cleavage in vitro. Treatment of DNA with diospyrin before addition of topoisomerase I has no effect. Preincubation of topoisomerase I with diospyrin before the addition of DNA in the relaxation reaction increases this inhibition. Our results suggest that this bis-naphthoquinone compound exerts its inhibitory effect by binding with the enzyme and stabilizing the topoisomerase I-DNA "cleavable complex." Diospyrin is a specific inhibitor of the parasitic topoisomerase I. It does not inhibit type II topoisomerase of L. donovani and requires much higher concentrations to inhibit type I topoisomerase of calf thymus. The potent inhibitory effect of diospyrin on type I DNA topoisomerase from L. donovani can be exploited for rational drug design in human leishmaniasis.
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Affiliation(s)
- S Ray
- Molecular Parasitology Laboratory, Indian Institute of Chemical Biology, Calcutta 700 032, India
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43
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Nenortas EC, Bodley AL, Shapiro TA. DNA topoisomerases: a new twist for antiparasitic chemotherapy? BIOCHIMICA ET BIOPHYSICA ACTA 1998; 1400:349-54. [PMID: 9748651 DOI: 10.1016/s0167-4781(98)00146-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The parasitic protozoa are notorious for their bizarre cellular structures and metabolic pathways, a characteristic also true for their nucleic acids. Despite these florid differences from mammalian cells, however, it has proven surprisingly difficult to devise novel chemotherapy against these pathogens. In recent years, the DNA topoisomerases from parasites have been the focus of considerable study, not only because they are intrinsically interesting, but also because they may provide a target for much-needed new antiparasitic chemotherapy.
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Affiliation(s)
- E C Nenortas
- Department of Medicine, Johns Hopkins School of Medicine, 303 Hunterian Building, 725 North Wolfe Street, Baltimore, MD 21205-2186, USA
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44
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Topoisomerase I-targeting drugs. ACTA ACUST UNITED AC 1998. [DOI: 10.1016/s1067-568x(98)80005-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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45
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Cortesi R, Esposito E, Maietti A, Menegatti E, Nastruzzi C. Formulation study for the antitumor drug camptothecin: liposomes, micellar solutions and a microemulsion. Int J Pharm 1997. [DOI: 10.1016/s0378-5173(97)00275-5] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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46
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Kawato Y, Terasawa H. 2 Recent Advances in the Medicinal Chemistry and Pharmacology of Camptothecin. PROGRESS IN MEDICINAL CHEMISTRY 1997. [DOI: 10.1016/s0079-6468(08)70105-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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47
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Abstract
Topoisomerases are enzymes that mediate topological changes in DNA that are essential for nucleic acid biosynthesis and for cell survival. The kinetoplastid protozoa, which include pathogenic trypanosomes and Leishmania, have yielded an interesting variety of purified topoisomerase activities as well as several topoisomerase genes. In these parasites, topoisomerases are involved in the metabolism of both nuclear and mitochondrial (kinetoplast) DNA. In this review, Christian Burri, Armette Bodley and Theresa Shapiro summarize what is known about topoisomerases in kinetoplastids, and consider the intriguing possibility that these enzymes may act as valuable antiparasite drug targets.
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Affiliation(s)
- C Burri
- Department of Medicine, Johns Hopkins University School of Medicine, 301 Hunterian Building, 725 North Wolfe Street, Baltimore, MD 21205-2185, USA
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