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Zhai BT, Tian H, Sun J, Zou JB, Zhang XF, Cheng JX, Shi YJ, Fan Y, Guo DY. Urokinase-type plasminogen activator receptor (uPAR) as a therapeutic target in cancer. J Transl Med 2022; 20:135. [PMID: 35303878 PMCID: PMC8932206 DOI: 10.1186/s12967-022-03329-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Accepted: 03/03/2022] [Indexed: 12/22/2022] Open
Abstract
Urokinase-type plasminogen activator receptor (uPAR) is an attractive target for the treatment of cancer, because it is expressed at low levels in healthy tissues but at high levels in malignant tumours. uPAR is closely related to the invasion and metastasis of malignant tumours, plays important roles in the degradation of extracellular matrix (ECM), tumour angiogenesis, cell proliferation and apoptosis, and is associated with the multidrug resistance (MDR) of tumour cells, which has important guiding significance for the judgement of tumor malignancy and prognosis. Several uPAR-targeted antitumour therapeutic agents have been developed to suppress tumour growth, metastatic processes and drug resistance. Here, we review the recent advances in the development of uPAR-targeted antitumor therapeutic strategies, including nanoplatforms carrying therapeutic agents, photodynamic therapy (PDT)/photothermal therapy (PTT) platforms, oncolytic virotherapy, gene therapy technologies, monoclonal antibody therapy and tumour immunotherapy, to promote the translation of these therapeutic agents to clinical applications.
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Affiliation(s)
- Bing-Tao Zhai
- State Key Laboratory of Research & Development of Characteristic Qin Medicine Resources (Cultivation), and Shaanxi Key Laboratory of Chinese Medicine Fundamentals and New Drugs Research, and Shaanxi Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, Shaanxi University of Chinese Medicine, Xi'an, 712046, China
| | - Huan Tian
- Xi'an Hospital of Traditional Chinese Medicine, Xi'an, 710021, China
| | - Jing Sun
- State Key Laboratory of Research & Development of Characteristic Qin Medicine Resources (Cultivation), and Shaanxi Key Laboratory of Chinese Medicine Fundamentals and New Drugs Research, and Shaanxi Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, Shaanxi University of Chinese Medicine, Xi'an, 712046, China
| | - Jun-Bo Zou
- State Key Laboratory of Research & Development of Characteristic Qin Medicine Resources (Cultivation), and Shaanxi Key Laboratory of Chinese Medicine Fundamentals and New Drugs Research, and Shaanxi Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, Shaanxi University of Chinese Medicine, Xi'an, 712046, China
| | - Xiao-Fei Zhang
- State Key Laboratory of Research & Development of Characteristic Qin Medicine Resources (Cultivation), and Shaanxi Key Laboratory of Chinese Medicine Fundamentals and New Drugs Research, and Shaanxi Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, Shaanxi University of Chinese Medicine, Xi'an, 712046, China
| | - Jiang-Xue Cheng
- State Key Laboratory of Research & Development of Characteristic Qin Medicine Resources (Cultivation), and Shaanxi Key Laboratory of Chinese Medicine Fundamentals and New Drugs Research, and Shaanxi Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, Shaanxi University of Chinese Medicine, Xi'an, 712046, China
| | - Ya-Jun Shi
- State Key Laboratory of Research & Development of Characteristic Qin Medicine Resources (Cultivation), and Shaanxi Key Laboratory of Chinese Medicine Fundamentals and New Drugs Research, and Shaanxi Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, Shaanxi University of Chinese Medicine, Xi'an, 712046, China
| | - Yu Fan
- State Key Laboratory of Research & Development of Characteristic Qin Medicine Resources (Cultivation), and Shaanxi Key Laboratory of Chinese Medicine Fundamentals and New Drugs Research, and Shaanxi Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, Shaanxi University of Chinese Medicine, Xi'an, 712046, China
| | - Dong-Yan Guo
- State Key Laboratory of Research & Development of Characteristic Qin Medicine Resources (Cultivation), and Shaanxi Key Laboratory of Chinese Medicine Fundamentals and New Drugs Research, and Shaanxi Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, Shaanxi University of Chinese Medicine, Xi'an, 712046, China.
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Metrangolo V, Ploug M, Engelholm LH. The Urokinase Receptor (uPAR) as a "Trojan Horse" in Targeted Cancer Therapy: Challenges and Opportunities. Cancers (Basel) 2021; 13:cancers13215376. [PMID: 34771541 PMCID: PMC8582577 DOI: 10.3390/cancers13215376] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 10/15/2021] [Accepted: 10/19/2021] [Indexed: 12/23/2022] Open
Abstract
Simple Summary Discovered more than three decades ago, the urokinase-type plasminogen activator receptor (uPAR) has now firmly established itself as a versatile molecular target holding promise for the treatment of aggressive malignancies. The copious abundance of uPAR in virtually all human cancerous tissues versus their healthy counterparts has fostered a gradual shift in the therapeutic landscape targeting this receptor from function inhibition to cytotoxic approaches to selectively eradicate the uPAR-expressing cells by delivering a targeted cytotoxic insult. Multiple avenues are being explored in a preclinical setting, including the more innovative immune- or stroma targeting therapies. This review discusses the current state of these strategies, their potentialities, and challenges, along with future directions in the field of uPAR targeting. Abstract One of the largest challenges to the implementation of precision oncology is identifying and validating selective tumor-driving targets to enhance the therapeutic efficacy while limiting off-target toxicity. In this context, the urokinase-type plasminogen activator receptor (uPAR) has progressively emerged as a promising therapeutic target in the management of aggressive malignancies. By focalizing the plasminogen activation cascade and subsequent extracellular proteolysis on the cell surface of migrating cells, uPAR endows malignant cells with a high proteolytic and migratory potential to dissolve the restraining extracellular matrix (ECM) barriers and metastasize to distant sites. uPAR is also assumed to choreograph multiple other neoplastic stages via a complex molecular interplay with distinct cancer-associated signaling pathways. Accordingly, high uPAR expression is observed in virtually all human cancers and is frequently associated with poor patient prognosis and survival. The promising therapeutic potential unveiled by the pleiotropic nature of this receptor has prompted the development of distinct targeted intervention strategies. The present review will focus on recently emerged cytotoxic approaches emphasizing the novel technologies and related limits hindering their application in the clinical setting. Finally, future research directions and emerging opportunities in the field of uPAR targeting are also discussed.
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Affiliation(s)
- Virginia Metrangolo
- The Finsen Laboratory, Rigshospitalet, DK-2200 Copenhagen, Denmark; (V.M.); (M.P.)
- Biotech Research & Innovation Centre (BRIC), Department of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Michael Ploug
- The Finsen Laboratory, Rigshospitalet, DK-2200 Copenhagen, Denmark; (V.M.); (M.P.)
- Biotech Research & Innovation Centre (BRIC), Department of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Lars H. Engelholm
- The Finsen Laboratory, Rigshospitalet, DK-2200 Copenhagen, Denmark; (V.M.); (M.P.)
- Biotech Research & Innovation Centre (BRIC), Department of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark
- Correspondence: ; Tel.: +45-31-43-20-77
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Pallarès V, Núñez Y, Sánchez-García L, Falgàs A, Serna N, Unzueta U, Gallardo A, Alba-Castellón L, Álamo P, Sierra J, Villaverde A, Vázquez E, Casanova I, Mangues R. Antineoplastic effect of a diphtheria toxin-based nanoparticle targeting acute myeloid leukemia cells overexpressing CXCR4. J Control Release 2021; 335:117-129. [PMID: 34004204 DOI: 10.1016/j.jconrel.2021.05.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 05/05/2021] [Accepted: 05/11/2021] [Indexed: 12/27/2022]
Abstract
Nanomedicine has opened an opportunity to improve current clinical practice by enhancing the selectivity in the delivery of antitumor drugs to specific cancer cells. These new strategies are able to bypass toxicity on normal cells increasing the effectiveness of current anticancer treatments. In acute myeloid leukemia (AML) current chemotherapy treatments generate a relevant toxic impact in normal cells and severe side effects or even patient death. In this study, we have designed a self-assembling protein nanoparticle, T22-DITOX-H6, which incorporates a ligand (T22) targeting CXCR4-overexpressing (CXCR4+) cells, and a potent cytotoxic diphtheria toxin domain. CXCR4 is overexpressed in AML leukemic cells and associates with poor prognosis, being, therefore, a relevant clinical target. We demonstrate here that T22-DITOX-H6 induces apoptosis in CXCR4+ leukemic cells through CXCR4-dependent internalization. In addition, repeated T22-DITOX-H6 treatment (10 μg/dose per 10 doses, intravenously injected) in a disseminated AML mouse model (NSG mice intravenously injected with THP-1-Luci cells, n = 10 per group) potently blocks the dissemination of AML cells in bone marrow, spleen and liver of treated mice, without inducing toxicity in healthy tissues. In conclusion, our strategy of selectively ablating CXCR4 positive leukemic cells by administering the T22-DITOX-H6 nanoparticle could be a promising treatment, especially in patients undergoing AML relapse after chemotherapy, in which leukemic cells overexpress CXCR4.
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Affiliation(s)
- Victor Pallarès
- Biomedical Research Institute Sant Pau (IIB-Sant Pau), Hospital de la Santa Creu i Sant Pau, Barcelona, Spain; Josep Carreras Research Institute, Barcelona, Spain; CIBER en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Barcelona, Spain
| | - Yáiza Núñez
- Biomedical Research Institute Sant Pau (IIB-Sant Pau), Hospital de la Santa Creu i Sant Pau, Barcelona, Spain; Josep Carreras Research Institute, Barcelona, Spain; CIBER en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Barcelona, Spain
| | - Laura Sánchez-García
- CIBER en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Barcelona, Spain; Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Barcelona, Spain; Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Aïda Falgàs
- Biomedical Research Institute Sant Pau (IIB-Sant Pau), Hospital de la Santa Creu i Sant Pau, Barcelona, Spain; Josep Carreras Research Institute, Barcelona, Spain; CIBER en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Barcelona, Spain
| | - Naroa Serna
- CIBER en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Barcelona, Spain; Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Barcelona, Spain; Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Ugutz Unzueta
- Biomedical Research Institute Sant Pau (IIB-Sant Pau), Hospital de la Santa Creu i Sant Pau, Barcelona, Spain; Josep Carreras Research Institute, Barcelona, Spain; CIBER en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Barcelona, Spain; Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Alberto Gallardo
- Biomedical Research Institute Sant Pau (IIB-Sant Pau), Hospital de la Santa Creu i Sant Pau, Barcelona, Spain; Department of Pathology, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
| | - Lorena Alba-Castellón
- Biomedical Research Institute Sant Pau (IIB-Sant Pau), Hospital de la Santa Creu i Sant Pau, Barcelona, Spain; Josep Carreras Research Institute, Barcelona, Spain
| | - Patricia Álamo
- Biomedical Research Institute Sant Pau (IIB-Sant Pau), Hospital de la Santa Creu i Sant Pau, Barcelona, Spain; Josep Carreras Research Institute, Barcelona, Spain; CIBER en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Barcelona, Spain
| | - Jorge Sierra
- Josep Carreras Research Institute, Barcelona, Spain; Department of Hematology, Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Antonio Villaverde
- CIBER en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Barcelona, Spain; Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Barcelona, Spain; Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Esther Vázquez
- CIBER en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Barcelona, Spain; Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Barcelona, Spain; Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona, Barcelona, Spain.
| | - Isolda Casanova
- Biomedical Research Institute Sant Pau (IIB-Sant Pau), Hospital de la Santa Creu i Sant Pau, Barcelona, Spain; Josep Carreras Research Institute, Barcelona, Spain; CIBER en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Barcelona, Spain.
| | - Ramon Mangues
- Biomedical Research Institute Sant Pau (IIB-Sant Pau), Hospital de la Santa Creu i Sant Pau, Barcelona, Spain; Josep Carreras Research Institute, Barcelona, Spain; CIBER en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Barcelona, Spain.
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Abstract
AB toxins with built-in cell targeting and endosomal escape mechanisms are attractive intracellular delivery vehicles. However, their compatibility with nucleic-acid-based therapeutics is not fully explored. Arnold et al. demonstrated the first functional siRNA delivery by diphtheria toxin (DT) in vitro, marking an important step in expanding the utility of AB toxins for nucleic acid delivery.
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Beilhartz GL, Sugiman-Marangos SN, Melnyk RA. Repurposing bacterial toxins for intracellular delivery of therapeutic proteins. Biochem Pharmacol 2017; 142:13-20. [DOI: 10.1016/j.bcp.2017.04.009] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 04/07/2017] [Indexed: 01/02/2023]
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Vandooren J, Opdenakker G, Loadman PM, Edwards DR. Proteases in cancer drug delivery. Adv Drug Deliv Rev 2016; 97:144-55. [PMID: 26756735 DOI: 10.1016/j.addr.2015.12.020] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Revised: 12/23/2015] [Accepted: 12/24/2015] [Indexed: 01/12/2023]
Abstract
Whereas protease inhibitors have been developed successfully against hypertension and viral infections, they have failed thus far as cancer drugs. With advances in cancer profiling we now better understand that the tumor "degradome" (i.e. the repertoire of proteases and their natural inhibitors and interaction partners) forms a complex network in which specific nodes determine the global outcome of manipulation of the protease web. However, knowing which proteases are active in the tumor micro-environment, we may tackle cancers with the use of Protease-Activated Prodrugs (PAPs). Here we exemplify this concept for metallo-, cysteine and serine proteases. PAPs not only exist as small molecular adducts, containing a cleavable substrate sequence and a latent prodrug, they are presently also manufactured as various types of nanoparticles. Although the emphasis of this review is on PAPs for treatment, it is clear that protease activatable probes and nanoparticles are also powerful tools for imaging purposes, including tumor diagnosis and staging, as well as visualization of tumor imaging during microsurgical resections.
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Affiliation(s)
- Jennifer Vandooren
- KU Leuven, University of Leuven, Department of Microbiology and Immunology, Rega Institute for Medical Research, Laboratory of Immunobiology, B-3000 Leuven, Belgium
| | - Ghislain Opdenakker
- KU Leuven, University of Leuven, Department of Microbiology and Immunology, Rega Institute for Medical Research, Laboratory of Immunobiology, B-3000 Leuven, Belgium
| | - Paul M Loadman
- Institute of Cancer Therapeutics, School of Life Sciences, University of Bradford, Bradford, Yorkshire BD7 1DP, UK
| | - Dylan R Edwards
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK; The Genome Analysis Centre, Norwich Research Park, Norwich NR4 7UH, UK.
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7
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Bekdash A, Darwish M, Timsah Z, Kassab E, Ghanem H, Najjar V, Ghosn M, Nasser S, El-Hajj H, Bazerbachi A, Liu S, Leppla SH, Frankel AE, Abi-Habib RJ. Phospho-MEK1/2 and uPAR Expression Determine Sensitivity of AML Blasts to a Urokinase-Activated Anthrax Lethal Toxin (PrAgU2/LF). Transl Oncol 2015; 8:347-357. [PMID: 26500025 PMCID: PMC4630967 DOI: 10.1016/j.tranon.2015.07.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Revised: 07/09/2015] [Accepted: 07/14/2015] [Indexed: 02/04/2023] Open
Abstract
In this study, we attempt to target both the urokinase plasminogen activator and the mitogen-activated protein kinase pathway in acute myeloid leukemia (AML) cell lines and primary AML blasts using PrAgU2/LF, a urokinase-activated anthrax lethal toxin. PrAgU2/LF was cytotoxic to five out of nine AML cell lines. Cytotoxicity of PrAgU2/LF appeared to be nonapoptotic and was associated with MAPK activation and urokinase activity because all the PrAgU2/LF-sensitive cell lines showed both uPAR expression and high levels of MEK1/2 phosphorylation. Inhibition of uPAR or desensitization of cells to MEK1/2 inhibition blocked toxicity of PrAgU2/LF, indicating requirement for both uPAR expression and MAPK activation for activity. PrAgU2/LF was also cytotoxic to primary blasts from AML patients, with blasts from four out of five patients showing a cytotoxic response to PrAgU2/LF. Cytotoxicity of primary AML blasts was also dependent on uPAR expression and phos-MEK1/2 levels. CD34(+) bone marrow blasts and peripheral blood mononuclear cells lacked uPAR expression and were resistant to PrAgU2/LF, demonstrating the lack of toxicity to normal hematological cells and, therefore, the tumor selectivity of this approach. Dose escalation in mice revealed that the maximal tolerated dose of PrAgU2/LF is at least 5.7-fold higher than that of the wild-type anthrax lethal toxin, PrAg/LF, further demonstrating the increased safety of this molecule. We have shown, in this study, that PrAgU2/LF is a novel, dual-specific molecule for the selective targeting of AML.
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Affiliation(s)
- Amira Bekdash
- Department of Natural Sciences, School of Arts and Sciences, Lebanese American University, Beirut 1102 2801, Lebanon
| | - Manal Darwish
- Department of Natural Sciences, School of Arts and Sciences, Lebanese American University, Beirut 1102 2801, Lebanon
| | - Zahra Timsah
- School of Molecular & Cellular Biology, University of Leeds, Leeds, LS2 9JT, UK
| | - Elias Kassab
- Department of Natural Sciences, School of Arts and Sciences, Lebanese American University, Beirut 1102 2801, Lebanon
| | - Hadi Ghanem
- Department of Internal Medicine, School of Medicine, Lebanese American University, Beirut 1102-2801, Lebanon
| | - Vicky Najjar
- Department of Pathology, School of Medicine, Lebanese American University, Beirut 1102-2801, Lebanon
| | - Marwan Ghosn
- Department of Pathology, School of Medicine, Lebanese American University, Beirut 1102-2801, Lebanon
| | - Selim Nasser
- Department of Pathology, School of Medicine, Lebanese American University, Beirut 1102-2801, Lebanon
| | - Hiba El-Hajj
- Department of Internal Medicine and Experimental Pathology, School of Medicine, American University of Beirut, Lebanon; Department of Immunology and Microbiology, School of Medicine, American University of Beirut, Lebanon
| | - Ali Bazerbachi
- Department of Internal Medicine, School of Medicine, American University of Beirut, Lebanon; Department of Anatomy, School of Medicine, American University of Beirut, Lebanon; Department of Cell Biology and Physiological Sciences, School of Medicine, American University of Beirut, Lebanon
| | - Shihui Liu
- Microbial Pathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892
| | - Stephen H Leppla
- Microbial Pathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892
| | - Arthur E Frankel
- Simmons Comprehensive Cancer Center, UT Southwestern Medical Center, Dallas, Texas 75390
| | - Ralph J Abi-Habib
- Department of Natural Sciences, School of Arts and Sciences, Lebanese American University, Beirut 1102 2801, Lebanon.
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8
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Tawil M, Bekdash A, Mroueh M, Daher CF, Abi-Habib RJ. Wild Carrot Oil Extract is Selectively Cytotoxic to Human Acute Myeloid Leukemia Cells. Asian Pac J Cancer Prev 2015; 16:761-7. [DOI: 10.7314/apjcp.2015.16.2.761] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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9
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Human recombinant arginase I (Co)-PEG5000 [HuArgI (Co)-PEG5000]-induced arginine depletion is selectively cytotoxic to human glioblastoma cells. J Neurooncol 2015; 122:75-85. [PMID: 25567351 DOI: 10.1007/s11060-014-1698-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Accepted: 12/19/2014] [Indexed: 10/24/2022]
Abstract
In this study, we attempt to target Arginine auxotrophy in glioblastoma multiforme (GBM) cells using a pegylated recombinant human Arginase I cobalt [HuArgI (Co)-PEG5000]. We tested and characterized the activity of HuArgI (Co)-PEG5000 on a panel of 9 GBM cell lines and on human fetal glial cells (SVG-p12). HuArgI (Co)-PEG5000 was cytotoxic to all GBM cells tested. SVG-p12 cells were not sensitive demonstrating the selective cytotoxicity of HuArgI (Co)-PEG5000-induced arginine deprivation. Addition of L-citrulline led to the rescue of 6 GBM cell lines but only at concentrations of 11.4 mM, reflecting the extent of arginine auxotrophy in GBM. The ability of L-citrulline to rescue cells was dependent on the expression of argininosuccinate synthetase-1 (ASS1) with the cells that were not rescued by L-citrulline being negative for ASS1 expression. Knocking-down ASS1 reversed the ability of L-citrulline to rescue GBM cells, further illustrating the dependence of arginine auxotrophy on ASS1 expression. Inhibition of autophagy increased cell sensitivity to HuArgI (Co)-PEG5000 indicating that, following arginine deprivation, autophagy plays a protective role in GBM cells. Analysis of the type of cell death revealed a lack of AnnexinV staining and caspase activation in HuArgI (Co)-PEG5000-treated cells, indicating that arginine deprivation induces caspase-independent, non-apoptotic cell death in GBM. We have shown that GBM cells are auxotrophic for arginine and can be selectively targeted using HuArgI (Co)-PEG5000-induced arginine depletion, thus demonstrating that L-Arginine deprivation is a potent and selective potential treatment for GBM.
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10
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Tafesse FG, Guimaraes CP, Maruyama T, Carette JE, Lory S, Brummelkamp TR, Ploegh HL. GPR107, a G-protein-coupled receptor essential for intoxication by Pseudomonas aeruginosa exotoxin A, localizes to the Golgi and is cleaved by furin. J Biol Chem 2014; 289:24005-18. [PMID: 25031321 PMCID: PMC4148833 DOI: 10.1074/jbc.m114.589275] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Revised: 07/08/2014] [Indexed: 12/25/2022] Open
Abstract
A number of toxins, including exotoxin A (PE) of Pseudomonas aeruginosa, kill cells by inhibiting protein synthesis. PE kills by ADP-ribosylation of the translation elongation factor 2, but many of the host factors required for entry, membrane translocation, and intracellular transport remain to be elucidated. A genome-wide genetic screen in human KBM7 cells was performed to uncover host factors used by PE, several of which were confirmed by CRISPR/Cas9-gene editing in a different cell type. Several proteins not previously implicated in the PE intoxication pathway were identified, including GPR107, an orphan G-protein-coupled receptor. GPR107 localizes to the trans-Golgi network and is essential for retrograde transport. It is cleaved by the endoprotease furin, and a disulfide bond connects the two cleaved fragments. Compromising this association affects the function of GPR107. The N-terminal region of GPR107 is critical for its biological function. GPR107 might be one of the long-sought receptors that associates with G-proteins to regulate intracellular vesicular transport.
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Affiliation(s)
- Fikadu G Tafesse
- From the Whitehead Institute for Biomedical Research and Massachusetts Institute of Technology, Cambridge, Massachusetts 02142
| | - Carla P Guimaraes
- From the Whitehead Institute for Biomedical Research and Massachusetts Institute of Technology, Cambridge, Massachusetts 02142
| | - Takeshi Maruyama
- From the Whitehead Institute for Biomedical Research and Massachusetts Institute of Technology, Cambridge, Massachusetts 02142
| | - Jan E Carette
- the Stanford School of Medicine, Stanford, California 94305
| | - Stephen Lory
- the Harvard Medical School, Boston, Massachusetts 02115, and
| | - Thijn R Brummelkamp
- the Netherlands Cancer Institute, Postbus 90203, 1006 BE Amsterdam, The Netherlands
| | - Hidde L Ploegh
- From the Whitehead Institute for Biomedical Research and Massachusetts Institute of Technology, Cambridge, Massachusetts 02142,
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11
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Bachran C, Gupta PK, Bachran S, Leysath CE, Hoover B, Fattah RJ, Leppla SH. Reductive methylation and mutation of an anthrax toxin fusion protein modulates its stability and cytotoxicity. Sci Rep 2014; 4:4754. [PMID: 24755540 PMCID: PMC3996465 DOI: 10.1038/srep04754] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Accepted: 04/01/2014] [Indexed: 02/02/2023] Open
Abstract
We characterized an anti-cancer fusion protein consisting of anthrax lethal factor (LF) and the catalytic domain of Pseudomonas exotoxin A by (i) mutating the N-terminal amino acids and by (ii) reductive methylation to dimethylate all lysines. Dimethylation of lysines was achieved quantitatively and specifically without affecting binding of the fusion protein to PA or decreasing the enzymatic activity of the catalytic moiety. Ubiquitination in vitro was drastically decreased for both the N-terminally mutated and dimethylated variants, and both appeared to be slightly more stable in the cytosol of treated cells. The dimethylated variant showed greatly reduced neutralization by antibodies to LF. The two described modifications offer unique advantages such as increased cytotoxic activity and diminished antibody recognition, and thus may be applicable to other therapeutic proteins that act in the cytosol of cells.
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Affiliation(s)
- Christopher Bachran
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
- These authors contributed equally to this work
| | - Pradeep K. Gupta
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
- These authors contributed equally to this work
| | - Silke Bachran
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Clinton E. Leysath
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Benjamin Hoover
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Rasem J. Fattah
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Stephen H. Leppla
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
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12
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An update in the use of antibodies to treat glioblastoma multiforme. Autoimmune Dis 2013; 2013:716813. [PMID: 24294521 PMCID: PMC3835613 DOI: 10.1155/2013/716813] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Accepted: 09/09/2013] [Indexed: 11/17/2022] Open
Abstract
Glioblastoma is a deadly brain disease and modest improvement in survival has been made. At initial diagnosis, treatment consists of maximum safe surgical resection, followed by temozolomide and chemoirradiation or adjuvant temozolomide alone. However, these treatments do not improve the prognosis and survival of patients. New treatment strategies are being sought according to the biology of tumors. The epidermal growth factor receptor has been considered as the hallmark in glioma tumors; thereby, some antibodies have been designed to bind to this receptor and block the downstream signaling pathways. Also, it is known that vascularization plays an important role in supplying new vessels to the tumor; therefore, new therapy has been guided to inhibit angiogenic growth factors in order to limit tumor growth. An innovative strategy in the treatment of glial tumors is the use of toxins produced by bacteria, which may be coupled to specific carrier-ligands and used for tumoral targeting. These carrier-ligands provide tumor-selective properties by the recognition of a cell-surface receptor on the tumor cells and promote their binding of the toxin-carrier complex prior to entry into the cell. Here, we reviewed some strategies to improve the management and treatment of glioblastoma and focused on the use of antibodies.
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Tanios R, Bekdash A, Kassab E, Stone E, Georgiou G, Frankel AE, Abi-Habib RJ. Human recombinant arginase I(Co)-PEG5000 [HuArgI(Co)-PEG5000]-induced arginine depletion is selectively cytotoxic to human acute myeloid leukemia cells. Leuk Res 2013; 37:1565-71. [PMID: 24018014 DOI: 10.1016/j.leukres.2013.08.007] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Revised: 08/06/2013] [Accepted: 08/07/2013] [Indexed: 01/14/2023]
Abstract
In this study, we target arginine auxotrophy of AML cell lines using human arginase I cobalt-PEG5000. HuArgI(Co)-PEG5000 was cytotoxic to all AML cell lines tested. Mononuclear cells and CD34(+) blasts were not sensitive demonstrating the selectivity of HuArgI(Co)-PEG5000-induced arginine deprivation. Addition of L-citrulline led to the rescue of five cell lines. The four cell lines that were not rescued by L-citrulline did not express argininosuccinate synthetase-1, indicating complete arginine auxotrophy. Inhibition of autophagy increased cell sensitivity to HuArgI(Co)-PEG5000 demonstrating the protective role of autophagy following arginine deprivation. We have shown that AML can be selectively targeted using HuArgI(Co)-PEG5000-induced arginine depletion.
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Affiliation(s)
- Rita Tanios
- Department of Natural Sciences, School of Arts and Sciences, Lebanese American University, Beirut 1102 2801, Lebanon
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14
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Li YM, Hall WA. Targeted toxins in brain tumor therapy. Toxins (Basel) 2010; 2:2645-62. [PMID: 22069569 PMCID: PMC3153175 DOI: 10.3390/toxins2112645] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2010] [Revised: 10/20/2010] [Accepted: 10/27/2010] [Indexed: 11/30/2022] Open
Abstract
Targeted toxins, also known as immunotoxins or cytotoxins, are recombinant molecules that specifically bind to cell surface receptors that are overexpressed in cancer and the toxin component kills the cell. These recombinant proteins consist of a specific antibody or ligand coupled to a protein toxin. The targeted toxins bind to a surface antigen or receptor overexpressed in tumors, such as the epidermal growth factor receptor or interleukin-13 receptor. The toxin part of the molecule in all clinically used toxins is modified from bacterial or plant toxins, fused to an antibody or carrier ligand. Targeted toxins are very effective against cancer cells resistant to radiation and chemotherapy. They are far more potent than any known chemotherapy drug. Targeted toxins have shown an acceptable profile of toxicity and safety in early clinical studies and have demonstrated evidence of a tumor response. Currently, clinical trials with some targeted toxins are complete and the final results are pending. This review summarizes the characteristics of targeted toxins and the key findings of the important clinical studies with targeted toxins in malignant brain tumor patients. Obstacles to successful treatment of malignant brain tumors include poor penetration into tumor masses, the immune response to the toxin component and cancer heterogeneity. Strategies to overcome these limitations are being pursued in the current generation of targeted toxins.
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Affiliation(s)
- Yan Michael Li
- Department of Neurosurgery, State University of New York Upstate Medical University, Syracuse, New York 13210, NY, USA.
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15
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Toxin-based therapeutic approaches. Toxins (Basel) 2010; 2:2519-83. [PMID: 22069564 PMCID: PMC3153180 DOI: 10.3390/toxins2112519] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2010] [Revised: 10/25/2010] [Accepted: 10/26/2010] [Indexed: 01/08/2023] Open
Abstract
Protein toxins confer a defense against predation/grazing or a superior pathogenic competence upon the producing organism. Such toxins have been perfected through evolution in poisonous animals/plants and pathogenic bacteria. Over the past five decades, a lot of effort has been invested in studying their mechanism of action, the way they contribute to pathogenicity and in the development of antidotes that neutralize their action. In parallel, many research groups turned to explore the pharmaceutical potential of such toxins when they are used to efficiently impair essential cellular processes and/or damage the integrity of their target cells. The following review summarizes major advances in the field of toxin based therapeutics and offers a comprehensive description of the mode of action of each applied toxin.
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16
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Protein toxins from plants and bacteria: Probes for intracellular transport and tools in medicine. FEBS Lett 2010; 584:2626-34. [DOI: 10.1016/j.febslet.2010.04.008] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2010] [Accepted: 04/07/2010] [Indexed: 01/07/2023]
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Horita H, Frankel AE, Thorburn A. Acute myeloid leukemia-targeted toxin activates both apoptotic and necroptotic death mechanisms. PLoS One 2008; 3:e3909. [PMID: 19079542 PMCID: PMC2592546 DOI: 10.1371/journal.pone.0003909] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2008] [Accepted: 11/14/2008] [Indexed: 11/18/2022] Open
Abstract
Background Acute myelogenous leukemia (AML) is the second most common leukemia with approximately 13,410 new cases and 8,990 deaths annually in the United States. A novel fusion toxin treatment, diphtheria toxin GM-CSF (DT-GMCSF) has been shown to selectively eliminate leukemic repopulating cells that are critical for the formation of AML. We previously showed that DT-GMCSF treatment of U937 cells, an AML cell line, causes activation of caspases and the induction of apoptosis. Methods and Findings In this study we further investigate the mechanisms of cell death induced by DT-GMCSF and show that, in addition to the activation of caspase-dependent apoptosis, DT-GMCSF also kills AML cells by simultaneously activating caspase-independent necroptosis. These mechanisms depend on the ability of the targeted toxin to inhibit protein synthesis, and are not affected by the receptor that is targeted or the mechanism through which protein synthesis is blocked. Conclusions We conclude that fusion toxin proteins may be effective for treating AML cells whether or not they are defective in apoptosis.
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Affiliation(s)
- Henrick Horita
- Department of Pharmacology, University of Colorado Denver School of Medicine, Aurora, Colorado, United States of America
| | - Arthur E. Frankel
- Scott & White Cancer Research Institute, Temple, Texas, United States of America
| | - Andrew Thorburn
- Department of Pharmacology, University of Colorado Denver School of Medicine, Aurora, Colorado, United States of America
- * E-mail:
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Singh R, Browning JL, Abi-Habib R, Wong K, Williams SA, Merchant R, Denmeade SR, Buckley TJ, Frankel AE. Recombinant prostate-specific antigen proaerolysin shows selective protease sensitivity and cell cytotoxicity. Anticancer Drugs 2007; 18:809-16. [PMID: 17581303 DOI: 10.1097/cad.0b013e3280bad82d] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Native proaerolysin is a channel-forming bacterial protoxin that binds to cell-surface receptors and then is activated by furin or furin-like proteases. We genetically engineered proaerolysin by replacing the furin-cleavage sequence with a prostate-specific antigen-selective sequence. The recombinant modified proaerolysin was expressed and purified from Aeromonas salmonicida in good yields and purity. Recombinant modified proaerolysin had no furin sensitivity and markedly increased prostate-specific antigen sensitivity relative to wild-type proaerolysin. Human prostate cancer cells were significantly more sensitive to recombinant modified proaerolysin in the presence of active prostate-specific antigen when compared with the absence of prostate-specific antigen or the presence of potent prostate-specific antigen inhibitors. Most normal human cells with the exception of prostate and renal epithelial cells showed very low sensitivity to recombinant modified proaerolysin. Our results suggest that recombinant modified proaerolysin is a potent prostate-specific antigen-sensitive protoxin that deserves further development for regional therapy of benign and malignant prostate growths.
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Affiliation(s)
- Ravibhushan Singh
- Cancer Research Institute, Scott & White Memorial Hospital, 5701 South Airport Road, Temple, TX 76502, USA
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Gabriel D, Campo MA, Gurny R, Lange N. Tailoring protease-sensitive photodynamic agents to specific disease-associated enzymes. Bioconjug Chem 2007; 18:1070-7. [PMID: 17477499 DOI: 10.1021/bc060321l] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We have developed novel polymeric photosensitizer prodrugs (PPPs) for improved photodynamic therapy. In PPPs, multiple photosensitizer units are covalently coupled to a polymeric backbone via protease-cleavable peptide linkers. These initially non-photoactive compounds become fluorescent and phototoxic after specific enzymatic cleavage of the peptide linkers and subsequent release of the photosensitizer moieties. Tethering the photosensitizer via a short and easily modified amino acid sequence to the polymeric backbone allows for the targeting of a wide variety of proteases. Model compounds, sensitive to trypsin-mediated cleavage, with different pheophorbide a-peptide loading ratios and backbone net charges were evaluated with respect to their solubility, "self-quenching" capacity of fluorescence emission, and reactive oxygen species (ROS) generation. In addition, linker sequence impaired selectivity toward enzymatic cleavage was demonstrated either by incubating PPPs with different enzymes having trypsin-like activity or by introducing a single d-arginine mutant in the peptide sequence. In vitro cell culture tests confirmed dose-dependent higher phototoxicity of enzymatically activated PPPs compared to the nonactivated conjugate after irradiation with white light. These data suggest that similar compounds adapted to disease-associated proteases can be used for selective photodynamic therapy.
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Affiliation(s)
- Doris Gabriel
- Laboratory of Pharmaceutics and Biopharmaceutics, Section of Pharmaceutical Sciences, University Lausanne, University Genève, 30 Quai Ernest-Ansermet, CH-1211, Geneva, Switzerland
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Di Cristina M, Minenkova O, Pavoni E, Beghetto E, Spadoni A, Felici F, Gargano N. A novel approach for identification of tumor-associated antigens expressed on the surface of tumor cells. Int J Cancer 2007; 120:1293-303. [PMID: 17163417 DOI: 10.1002/ijc.22395] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
To improve tumor targeting in a subset of patients, where tumor cells do not express the well-known tumor antigens widely used in immunotherapy, we have developed a novel biotechnological tool. It is useful for tumors of various origins for the identification of tumor-associated proteins, which are differentially expressed in tumor cells with respect to normal tissue, and exposed on the cell surface. For this purpose, a combination of techniques, such as "suppression subtractive hybridization" and "transmembrane trapping," was employed. In applying this novel approach to breast cancer, we identified a large panel of cDNA fragments encoding for the well-known tumor-associated surface antigens, such as erb-B2, erbB3 and the urokinase receptor and, more importantly, for several clones overexpressed in breast cancer, whose cDNA fragments match the sequences of hypothetical transmembrane proteins with unknown function. The latter may represent novel tumor-specific targets.
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Affiliation(s)
- Manlio Di Cristina
- Kenton Laboratories, Via Pontina Km. 30.400, 00040 Pomezia (Rome), Italy
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21
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Abstract
Immunotoxins are proteins used to treat cancer that are composed of an antibody fragment linked to a toxin. The immunotoxin binds to a surface antigen on a cancer cell, enters the cell by endocytosis, and kills it. The most potent immunotoxins are made from bacterial and plant toxins. Refinements over many years have produced recombinant immunotoxins; these therapeutic proteins are made using protein engineering. Individual immunotoxins are designed to treat specific cancers. To date, most success has been achieved treating hematologic tumors. Obstacles to successful treatment of solid tumors include poor penetration into tumor masses and the immune response to the toxin component of the immunotoxin, which limits the number of cycles that can be given. Strategies to overcome these limitations are being pursued.
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Affiliation(s)
- Ira Pastan
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA.
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22
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Abi-Habib RJ, Singh R, Leppla SH, Greene JJ, Ding Y, Berghuis B, Duesbery NS, Frankel AE. Systemic anthrax lethal toxin therapy produces regressions of subcutaneous human melanoma tumors in athymic nude mice. Clin Cancer Res 2007; 12:7437-43. [PMID: 17189417 DOI: 10.1158/1078-0432.ccr-06-2019] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Anthrax Lethal Toxin (LeTx), composed of protective antigen and lethal factor, catalytically cleaves mitogen-activated protein kinase (MAPK) kinases and inhibits the MAPK signaling pathways. The majority of metastatic melanomas possess the V599E BRAF mutation, which constitutively activates MAPK1/2 signaling. LeTx is cytotoxic to BRAF mutant melanoma cell lines in vitro, whereas most normal cells are resistant to this toxin. In this study, we determine the in vivo potency and safety of systemically administered LeTx. EXPERIMENTAL DESIGN A s.c. xenograft melanoma model in athymic nude mice was treated with different i.p. doses of LeTx. RESULTS In this study, we show that in vivo systemic LeTx treatment of s.c. xenograft melanoma tumors in athymic nude mice yields partial and complete tumor regressions with minor toxicity to mice. When animal toxicity was observed, we did not find any histologic evidence of tissue damage. CONCLUSIONS LeTx is one of the rare targeted agents to produce complete remissions of human melanomas in an animal model and thus warrants further preclinical development.
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Affiliation(s)
- Ralph J Abi-Habib
- Cancer Research Institute, Scott & White Memorial Hospital, Temple, Texas 76502, USA
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23
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Abi-Habib RJ, Singh R, Liu S, Bugge TH, Leppla SH, Frankel AE. A urokinase-activated recombinant anthrax toxin is selectively cytotoxic to many human tumor cell types. Mol Cancer Ther 2007; 5:2556-62. [PMID: 17041100 DOI: 10.1158/1535-7163.mct-06-0315] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Urokinase plasminogen activator (uPA) is a tumor-specific protease highly expressed in several types of solid tumors and rarely present on normal cells under physiologic conditions. Due to its high expression on metastatic tumors, several different strategies have been used to target the urokinase system. These have mostly led to tumor growth inhibition rather than tumor regression. A different approach was adopted by replacing the furin activation site on a recombinant anthrax toxin with a urokinase activation site. The resulting toxin, PrAgU2/FP59, was highly potent against tumors both in vitro and in vivo. In this study, we show that PrAgU2/FP59 is toxic to a wide range of tumor cell lines, including non-small cell lung cancer, pancreatic cancer, and basal-like breast cancer cell lines. Of the few cell lines found to be resistant to PrAgU2/FP59, most became sensitive upon addition of exogenous pro-uPA. PrAgU2/FP59 was much less toxic to normal human cells. The potency of PrAgU2/FP59 was dependent on anthrax toxin receptor, uPA receptor, and uPA levels but not on total plasminogen activator inhibitor-1 levels. In this study, we show that PrAgU2/FP59 is a wide-range, highly potent, and highly selective toxin that is capable of specifically targeting uPA-expressing tumor cells, independently of the tissue of origin of these cells. Furthermore, we identify three molecular markers, anthrax toxin receptor, uPA, and uPA receptor, which can be used as predictors of tumor cell sensitivity to PrAgU2/FP59.
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Affiliation(s)
- Ralph J Abi-Habib
- Cancer Research Institute of Scott & White Memorial Hospital, Temple, Texas 76502, USA
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Song KW, Lipton J. Is it appropriate to offer allogeneic hematopoietic stem cell transplantation to patients with primary refractory acute myeloid leukemia? Bone Marrow Transplant 2005; 36:183-91. [PMID: 15937497 DOI: 10.1038/sj.bmt.1705038] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Although continued advances have been made in the treatment of acute myeloid leukemia (AML), approximately 20-30% of patients will never achieve a remission. For these patients with primary refractory AML, the only curative option remains an allogeneic stem cell transplant. Allogeneic transplantation provides the ability to administer myeloablative doses of chemotherapy or chemoradiotherapy, as well as the advantage of a possible graft-versus-leukemia effect. Difficulty in interpreting the literature is due to selection bias, in particular, the varying definitions of primary refractory disease with respect to the morphological criteria and the number of induction regimen required before being defined as being refractory. Regardless, it is a procedure with high treatment-related mortality and risk of relapse. Most studies demonstrate an event-free survival of 10-20% at 5 years. Predictive factors of outcome include blast cell count in the marrow, karyotype, the number of prior regimen, age, performance status and availability of a related donor. These prognostic factors should be considered prior to offering allogeneic transplantation for primary refractory AML. Those patients with many favorable prognostic factors and an HLA-matched related donor available would be the best candidate for the procedure. Those with many poor prognostic factors and only an unrelated donor available may be better served by being offered palliation or being enrolled in investigational studies.
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Affiliation(s)
- K W Song
- The Leukemia/Bone Marrow Transplantation Program of British Columbia, Vancouver Hospital and Health Sciences Center, British Columbia Cancer Agency, University of British Columbia, Vancouver, British Columbia, Canada.
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Abi-Habib RJ, Urieto JO, Liu S, Leppla SH, Duesbery NS, Frankel AE. BRAF status and mitogen-activated protein/extracellular signal-regulated kinase kinase 1/2 activity indicate sensitivity of melanoma cells to anthrax lethal toxin. Mol Cancer Ther 2005; 4:1303-10. [PMID: 16170021 DOI: 10.1158/1535-7163.mct-05-0145] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Anthrax lethal toxin, composed of protective antigen and lethal factor, was tested for cytotoxicity to human melanoma cell lines and normal human cells. Eleven of 18 melanoma cell lines were sensitive to anthrax lethal toxin (IC(50) < 400 pmol/L) and 10 of these 11 sensitive cell lines carried the V599E BRAF mutation. Most normal cell types (10 of 15) were not sensitive to anthrax lethal toxin and only 5 of 15 normal human cell types were sensitive to anthrax lethal toxin (IC(50) < 400 pmol/L). These cells included monocytes and a subset of endothelial cells. In both melanoma cell lines and normal cells, anthrax toxin receptor expression levels did not correlate with anthrax lethal toxin cytotoxicity. Furthermore, an anthrax toxin receptor-deficient cell line (PR230) did not show any enhanced sensitivity to anthrax lethal toxin when transfected with anthrax toxin receptor. Anthrax lethal toxin toxicity correlated with elevated phosphorylation levels of mitogen-activated protein/extracellular signal-regulated kinase kinase (MEK) 1/2 in both melanoma cell lines and normal cells. Anthrax lethal toxin-sensitive melanoma cell lines and normal cells had higher phospho-MEK1/2 levels than anthrax lethal toxin-resistant melanoma cell lines and normal tissue types. U0126, a specific MEK1/2 inhibitor, was not toxic to anthrax lethal toxin-resistant melanoma cell lines but was toxic to 8 of 11 anthrax lethal toxin-sensitive cell lines. These results show that anthrax lethal toxin toxicity correlates with elevated levels of active MEK1/2 pathway but not with anthrax toxin receptor expression levels in both normal and malignant tissues. Anthrax lethal toxin may be a useful therapeutic for melanoma patients, especially those carrying the V599E BRAF mutation with constitutive activation of the mitogen-activated protein kinase pathway.
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Affiliation(s)
- Ralph J Abi-Habib
- Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA
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Westcott MM, Abi-Habib RJ, Cohen KA, Willingham MC, Liu S, Bugge TH, Leppla SH, Frankel AE. Diphtheria toxin-murine granulocyte-macrophage colony-stimulating factor–induced hepatotoxicity is mediated by Kupffer cells. Mol Cancer Ther 2004. [DOI: 10.1158/1535-7163.1681.3.12] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
DT388GMCSF, a fusion toxin composed of the NH2-terminal region of diphtheria toxin (DT) fused to human granulocyte-macrophage colony-stimulating factor (GMCSF) has shown efficacy in the treatment of acute myeloid leukemia. However, the primary dose-limiting side effect is liver toxicity. We have reproduced liver toxicity in rats using the rodent cell-tropic DT-murine GMCSF (DT390mGMCSF). Serum aspartate aminotransferase and alanine aminotransferase were elevated 15- and 4-fold, respectively, in DT390mGMCSF-treated rats relative to controls. Histologic analysis revealed hepatocyte swelling; however, this did not lead to hepatic necrosis or overt histopathologic changes in the liver. Immunohistochemical staining showed apoptotic cells in the sinusoids, and depletion of cells expressing the monocyte/macrophage markers, ED1 and ED2, indicating that Kupffer cells (KC) are targets of DT390mGMCSF. In contrast, sinusoidal endothelial cells seemed intact. In vitro, DT390mGMCSF was directly cytotoxic to primary KC but not hepatocytes. Two related fusion toxins, DT388GMCSF, which targets the human GMCSF receptor, and DT390mIL-3, which targets the rodent IL-3 receptor, induced a less than 2-fold elevation in serum transaminases and did not deplete KC in vivo. In addition, DTU2mGMCSF, a modified form of DT390mGMCSF with enhanced tumor cell specificity, was not hepatotoxic and was significantly less toxic to KC in vivo and in vitro. These results show that DT390mGMCSF causes liver toxicity by targeting KC, and establish a model for studying how this leads to hepatocyte injury. Furthermore, alternative fusion toxins with potentially reduced hepatotoxicity are presented.
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Affiliation(s)
| | | | | | - Mark C. Willingham
- 3Pathology, Wake Forest University School of Medicine, Winston-Salem, North Carolina
| | - Shihui Liu
- 4Microbial Pathogenesis Section, National Institute of Allergy and Infectious Diseases; and
| | - Thomas H. Bugge
- 5Oral and Pharyngeal Cancer Branch, National Institute of Dental and Craniofacial Research, NIH, Bethesda, Maryland
| | - Stephen H. Leppla
- 4Microbial Pathogenesis Section, National Institute of Allergy and Infectious Diseases; and
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