1
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Havaei SM, Aucoin MG, Jahanian-Najafabadi A. Pseudomonas Exotoxin-Based Immunotoxins: Over Three Decades of Efforts on Targeting Cancer Cells With the Toxin. Front Oncol 2021; 11:781800. [PMID: 34976821 PMCID: PMC8716853 DOI: 10.3389/fonc.2021.781800] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 11/16/2021] [Indexed: 12/16/2022] Open
Abstract
Cancer is one of the prominent causes of death worldwide. Despite the existence of various modalities for cancer treatment, many types of cancer remain uncured or develop resistance to therapeutic strategies. Furthermore, almost all chemotherapeutics cause a range of side effects because they affect normal cells in addition to malignant cells. Therefore, the development of novel therapeutic agents that are targeted specifically toward cancer cells is indispensable. Immunotoxins (ITs) are a class of tumor cell-targeted fusion proteins consisting of both a targeting moiety and a toxic moiety. The targeting moiety is usually an antibody/antibody fragment or a ligand of the immune system that can bind an antigen or receptor that is only expressed or overexpressed by cancer cells but not normal cells. The toxic moiety is usually a protein toxin (or derivative) of animal, plant, insect, or bacterial origin. To date, three ITs have gained Food and Drug Administration (FDA) approval for human use, including denileukin diftitox (FDA approval: 1999), tagraxofusp (FDA approval: 2018), and moxetumomab pasudotox (FDA approval: 2018). All of these ITs take advantage of bacterial protein toxins. The toxic moiety of the first two ITs is a truncated form of diphtheria toxin, and the third is a derivative of Pseudomonas exotoxin (PE). There is a growing list of ITs using PE, or its derivatives, being evaluated preclinically or clinically. Here, we will review these ITs to highlight the advances in PE-based anticancer strategies, as well as review the targeting moieties that are used to reduce the non-specific destruction of non-cancerous cells. Although we tried to be as comprehensive as possible, we have limited our review to those ITs that have proceeded to clinical trials and are still under active clinical evaluation.
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Affiliation(s)
- Seyed Mehdi Havaei
- Department of Pharmaceutical Biotechnology, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Marc G. Aucoin
- Department of Chemical Engineering, Faculty of Engineering, University of Waterloo, Waterloo, ON, Canada
| | - Ali Jahanian-Najafabadi
- Department of Pharmaceutical Biotechnology, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran
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2
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Dieffenbach M, Pastan I. Mechanisms of Resistance to Immunotoxins Containing Pseudomonas Exotoxin A in Cancer Therapy. Biomolecules 2020; 10:E979. [PMID: 32630017 PMCID: PMC7408526 DOI: 10.3390/biom10070979] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 06/25/2020] [Accepted: 06/27/2020] [Indexed: 02/06/2023] Open
Abstract
Immunotoxins are a class of targeted cancer therapeutics in which a toxin such as Pseudomonas exotoxin A (PE) is linked to an antibody or cytokine to direct the toxin to a target on cancer cells. While a variety of PE-based immunotoxins have been developed and a few have demonstrated promising clinical and preclinical results, cancer cells frequently have or develop resistance to these immunotoxins. This review presents our current understanding of the mechanism of action of PE-based immunotoxins and discusses cellular mechanisms of resistance that interfere with various steps of the pathway. These steps include binding of the immunotoxin to the target antigen, internalization, intracellular processing and trafficking to reach the cytosol, inhibition of protein synthesis through ADP-ribosylation of elongation factor 2 (EF2), and induction of apoptosis. Combination therapies that increase immunotoxin action and overcome specific mechanisms of resistance are also reviewed.
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Affiliation(s)
| | - Ira Pastan
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892-4264, USA;
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3
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Masilamani AP, Dettmer-Monaco V, Monaco G, Cathomen T, Kuckuck I, Schultze-Seemann S, Huber N, Wolf P. An Anti-PSMA Immunotoxin Reduces Mcl-1 and Bcl2A1 and Specifically Induces in Combination with the BAD-Like BH3 Mimetic ABT-737 Apoptosis in Prostate Cancer Cells. Cancers (Basel) 2020; 12:cancers12061648. [PMID: 32580291 PMCID: PMC7352695 DOI: 10.3390/cancers12061648] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 05/29/2020] [Accepted: 06/03/2020] [Indexed: 12/25/2022] Open
Abstract
Background: Upregulation of anti-apoptotic Bcl-2 proteins in advanced prostate cancer leads to therapeutic resistance by prevention of cell death. New therapeutic approaches aim to target the Bcl-2 proteins for the restoration of apoptosis. Methods: The immunotoxin hD7-1(VL-VH)-PE40 specifically binds to the prostate specific membrane antigen (PSMA) on prostate cancer cells and inhibits protein biosynthesis. It was tested with respect to its effects on the expression of anti-apoptotic Bcl-2 proteins. Combination with the BAD-like mimetic ABT-737 was examined on prostate cancer cells and 3D spheroids and in view of tumor growth and survival in the prostate cancer SCID mouse xenograft model. Results: The immunotoxin led to a specific inhibition of Mcl-1 and Bcl2A1 expression in PSMA expressing target cells. Its combination with ABT-737, which inhibits Bcl-2, Bcl-xl, and Bcl-w, led to an induction of the intrinsic apoptotic pathway and to a synergistic cytotoxicity in prostate cancer cells and 3D spheroids. Furthermore, combination therapy led to a significantly prolonged survival of mice bearing prostate cancer xenografts based on an inhibition of tumor growth. Conclusion: The combination therapy of anti-PSMA immunotoxin plus ABT-737 represents the first tumor-specific therapeutic approach on the level of Bcl-2 proteins for the induction of apoptosis in prostate cancer.
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Affiliation(s)
- Anie P. Masilamani
- Department of Urology, Medical Center—University of Freiburg, 79106 Freiburg, Germany; (A.P.M.); (I.K.); (S.S.-S.); (N.H.)
- Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany; (V.D.-M.); (G.M.); (T.C.)
| | - Viviane Dettmer-Monaco
- Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany; (V.D.-M.); (G.M.); (T.C.)
- Institute for Transfusion Medicine and Gene Therapy, Medical Center—University of Freiburg, 79106 Freiburg, Germany
- Center for Chronic Immunodeficiency, University of Freiburg, 79106 Freiburg, Germany
| | - Gianni Monaco
- Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany; (V.D.-M.); (G.M.); (T.C.)
- Institute for Transfusion Medicine and Gene Therapy, Medical Center—University of Freiburg, 79106 Freiburg, Germany
- Center for Chronic Immunodeficiency, University of Freiburg, 79106 Freiburg, Germany
| | - Toni Cathomen
- Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany; (V.D.-M.); (G.M.); (T.C.)
- Institute for Transfusion Medicine and Gene Therapy, Medical Center—University of Freiburg, 79106 Freiburg, Germany
- Center for Chronic Immunodeficiency, University of Freiburg, 79106 Freiburg, Germany
| | - Irina Kuckuck
- Department of Urology, Medical Center—University of Freiburg, 79106 Freiburg, Germany; (A.P.M.); (I.K.); (S.S.-S.); (N.H.)
- Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany; (V.D.-M.); (G.M.); (T.C.)
| | - Susanne Schultze-Seemann
- Department of Urology, Medical Center—University of Freiburg, 79106 Freiburg, Germany; (A.P.M.); (I.K.); (S.S.-S.); (N.H.)
- Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany; (V.D.-M.); (G.M.); (T.C.)
| | - Nathalie Huber
- Department of Urology, Medical Center—University of Freiburg, 79106 Freiburg, Germany; (A.P.M.); (I.K.); (S.S.-S.); (N.H.)
- Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany; (V.D.-M.); (G.M.); (T.C.)
| | - Philipp Wolf
- Department of Urology, Medical Center—University of Freiburg, 79106 Freiburg, Germany; (A.P.M.); (I.K.); (S.S.-S.); (N.H.)
- Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany; (V.D.-M.); (G.M.); (T.C.)
- Correspondence: ; Tel.: +49-761-270-28921
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4
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Nichetti F, Marra A, Corti F, Guidi A, Raimondi A, Prinzi N, de Braud F, Pusceddu S. The Role of Mesothelin as a Diagnostic and Therapeutic Target in Pancreatic Ductal Adenocarcinoma: A Comprehensive Review. Target Oncol 2019; 13:333-351. [PMID: 29656320 DOI: 10.1007/s11523-018-0567-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Mesothelin is a tumor differentiation antigen, which is highly expressed in several solid neoplasms, including pancreatic cancer. Its selective expression on malignant cells and on only a limited number of healthy tissues has made it an interesting candidate for investigation as a diagnostic and prognostic biomarker and as a therapeutic target. Based on a strong preclinical rationale, a number of therapeutic agents targeting mesothelin have entered clinical trials, including immunotoxins, monoclonal antibodies, antibody-drug conjugates, cancer vaccines, and adoptive T cell therapies with chimeric antigen receptors. In pancreatic cancer, mesothelin has been investigated mainly to address two unmet issues: the urgent need for new laboratory techniques for early tumor detection and the lack of successfully targetable oncogenic alterations for patients' treatment. In this review, we describe the clinicopathological significance of mesothelin expression in pancreatic cancer initiation and progression, we summarize available studies evaluating mesothelin as a potential diagnostic and prognostic biomarker in this disease, and we discuss current evidence and future perspectives of preclinical and clinical studies testing mesothelin as a molecular target for pancreatic cancer treatment.
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Affiliation(s)
- Federico Nichetti
- Department of Medical Oncology, Fondazione IRCCS Istituto Nazionale dei Tumori, Via Venezian 1, 20133, Milan, Italy.
| | - Antonio Marra
- Medical Oncology Unit, Azienda Ospedaliera San Paolo, Milan, Italy
| | - Francesca Corti
- Department of Medical Oncology, Fondazione IRCCS Istituto Nazionale dei Tumori, Via Venezian 1, 20133, Milan, Italy
| | - Alessandro Guidi
- Medical Oncology Unit, Azienda Ospedaliera San Gerardo, Monza, Italy
| | - Alessandra Raimondi
- Department of Medical Oncology, Fondazione IRCCS Istituto Nazionale dei Tumori, Via Venezian 1, 20133, Milan, Italy
| | - Natalie Prinzi
- Department of Medical Oncology, Fondazione IRCCS Istituto Nazionale dei Tumori, Via Venezian 1, 20133, Milan, Italy
| | - Filippo de Braud
- Department of Medical Oncology, Fondazione IRCCS Istituto Nazionale dei Tumori, Via Venezian 1, 20133, Milan, Italy
- Department of Oncology, Università degli Studi di Milano, Milan, Italy
| | - Sara Pusceddu
- Department of Medical Oncology, Fondazione IRCCS Istituto Nazionale dei Tumori, Via Venezian 1, 20133, Milan, Italy
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5
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Wolf P. Tumor-Specific Induction of the Intrinsic Apoptotic Pathway-A New Therapeutic Option for Advanced Prostate Cancer? Front Oncol 2019; 9:590. [PMID: 31312616 PMCID: PMC6614431 DOI: 10.3389/fonc.2019.00590] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 06/17/2019] [Indexed: 12/18/2022] Open
Affiliation(s)
- Philipp Wolf
- Department of Urology, Medical Center - University of Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
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6
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Yu X, Dobrikov M, Keir ST, Gromeier M, Pastan IH, Reisfeld R, Bigner DD, Chandramohan V. Synergistic antitumor effects of 9.2.27-PE38KDEL and ABT-737 in primary and metastatic brain tumors. PLoS One 2019; 14:e0210608. [PMID: 30625226 PMCID: PMC6326518 DOI: 10.1371/journal.pone.0210608] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 12/30/2018] [Indexed: 12/30/2022] Open
Abstract
Standard treatment, unfortunately, yields a poor prognosis for patients with primary or metastatic cancers in the central nervous system, indicating a necessity for novel therapeutic agents. Immunotoxins (ITs) are a class of promising therapeutic candidates produced by fusing antibody fragments with toxin moieties. In this study, we investigated if inherent resistance to IT cytotoxicity can be overcome by rational combination with pro-apoptotic enhancers. Therefore, we combined ITs (9.2.27-PE38KDEL or Mel-14-PE38KDEL) targeting chondroitin sulfate proteoglycan 4 (CSPG4) with a panel of Bcl-2 family inhibitors (ABT-737, ABT-263, ABT-199 [Venetoclax], A-1155463, and S63845) against patient-derived glioblastoma, melanoma, and breast cancer cells/cell lines. In vitro cytotoxicity assays demonstrated that the addition of the ABT compounds, specifically ABT-737, sensitized the different tumors to IT treatment, and improved the IC50 values of 9.2.27-PE38KDEL up to >1,000-fold. Mechanistic studies using 9.2.27-PE38KDEL and ABT-737 revealed that increased levels of intracellular IT, processed (active) exotoxin, and PARP cleavage correlated with the enhanced sensitivity to the combination treatment. Furthermore, we confirmed the synergistic effect of 9.2.27-PE38KDEL and ABT-737 combination therapy in orthotopic GBM xenograft and cerebral melanoma metastasis models in nude mice. Our study defines strategies for overcoming IT resistance and enhancing specific antitumor cytotoxicity in primary and metastatic brain tumors.
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Affiliation(s)
- Xin Yu
- Department of Pathology, Duke University Medical Center, Durham, NC, United States of America
| | - Mikhail Dobrikov
- Department of Neurosurgery, Duke University Medical Center, Durham, NC, United States of America
| | - Stephen T. Keir
- Department of Neurosurgery, Duke University Medical Center, Durham, NC, United States of America
| | - Matthias Gromeier
- Department of Neurosurgery, Duke University Medical Center, Durham, NC, United States of America
| | - Ira H. Pastan
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, United States of America
| | - Ralph Reisfeld
- Department of Immunology and Microbiology, The Scripps Institute, La Jolla, CA, United States of America
| | - Darell D. Bigner
- Department of Pathology, Duke University Medical Center, Durham, NC, United States of America
- Department of Neurosurgery, Duke University Medical Center, Durham, NC, United States of America
| | - Vidyalakshmi Chandramohan
- Department of Pathology, Duke University Medical Center, Durham, NC, United States of America
- Department of Neurosurgery, Duke University Medical Center, Durham, NC, United States of America
- * E-mail:
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7
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Noll T, Schultze-Seemann S, Kuckuck I, Michalska M, Wolf P. Synergistic cytotoxicity of a prostate cancer-specific immunotoxin in combination with the BH3 mimetic ABT-737. Cancer Immunol Immunother 2018; 67:413-422. [PMID: 29188305 PMCID: PMC11028116 DOI: 10.1007/s00262-017-2097-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 11/21/2017] [Indexed: 10/18/2022]
Abstract
In many tumors, including prostate cancer, anti-apoptotic members of the Bcl-2 family are overexpressed and cause cell death resistance, which is a typical hallmark of cancer. Different therapeutic approaches, therefore, aim to restore the death mechanisms for enhanced apoptosis. Our recombinant immunotoxin D7(VL-VH)-PE40 is composed of the scFv D7(VL-VH) against the prostate-specific membrane antigen (PSMA) on the surface of prostate cancer cells and of the cytotoxic domain of the bacterial toxin Pseudomonas Exotoxin A (PE40). Since Pseudomonas Exotoxin A-based immunotoxins are known to preferentially inhibit the expression of the anti-apoptotic protein Mcl-1, the rationale was to test our immunotoxin in combination with the BH3 mimetic ABT-737, which specifically inhibits Bcl-2, Bcl-xl, and Bcl-w for enhanced induction of apoptosis in prostate cancer cells. The immunotoxin showed high and specific binding and cytotoxicity against PSMA expressing prostate cancer cells marked by a direct inhibition of Mcl-1. The combination of the immunotoxin with a subtoxic concentration of ABT-737 caused additive or even synergistic effects, which were based on an enhanced apoptosis induction as detected by poly(ADP-ribose) polymerase (PARP) and Caspase-3 cleavage in Western blot. Our study shows that the combination therapy of immunotoxin plus ABT-737 is a promising approach for the future treatment of advanced prostate cancer to improve therapeutic efficacy and to reduce adverse side effects.
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Affiliation(s)
- Theresa Noll
- Department of Urology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Breisacher Str. 66, 79106, Freiburg, Germany
| | - Susanne Schultze-Seemann
- Department of Urology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Breisacher Str. 66, 79106, Freiburg, Germany
| | - Irina Kuckuck
- Department of Urology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Breisacher Str. 66, 79106, Freiburg, Germany
| | - Marta Michalska
- Department of Urology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Breisacher Str. 66, 79106, Freiburg, Germany
| | - Philipp Wolf
- Department of Urology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Breisacher Str. 66, 79106, Freiburg, Germany.
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8
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Antignani A, Segal D, Simon N, Kreitman RJ, Huang D, FitzGerald DJ. Essential role for Bim in mediating the apoptotic and antitumor activities of immunotoxins. Oncogene 2017; 36:4953-4962. [PMID: 28436946 PMCID: PMC11302550 DOI: 10.1038/onc.2017.111] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 03/08/2017] [Accepted: 03/14/2017] [Indexed: 01/14/2023]
Abstract
Protein synthesis is crucial for regulating cell homeostasis and, when unrestricted, it can lead to tumorigenesis. Immunotoxins derived from Pseudomonas exotoxin are antibody-toxin fusion proteins that inhibit protein synthesis of mammalian cells via ADP-ribosylation of the eukaryotic elongation factor-2. Here we investigate the role of the Bcl-2 family proteins in the response of cancer cells to immunotoxin challenge. Besides the well-known reduction of the prosurvival Bcl-2 family member, Mcl-1, following inhibition of protein synthesis, we show for the first time that immunotoxins also reduce the levels of selected proapoptotic BH-3-only proteins. Among these, only Bim protein levels correlated with the ability of immunotoxins to induce an apoptotic response. To support our findings, we verified that a Bim knockout completely abolished immunotoxin-mediated apoptosis. Further, mice bearing either wild-type or Bid knockout tumors responded to immunotoxin treatment with a decrease in growth kinetics, whereas mice engrafted with Bim knockout tumors showed no reduction in tumor size or prolongation of survival following immunotoxin treatment. From these results, we conclude that Bim expression is a major susceptibility factor for tumor cell death and, as such, constitutes a potential biomarker that could be evaluated before immunotoxin treatment. In support of this hypothesis, clinically, we analyzed patient cells before immunotoxin treatment and report that samples of hairy cell leukemia with high levels of Bim protein responded with a greater decrease in leukemic cell count compared with those samples expressing a low level of Bim.
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Affiliation(s)
- A Antignani
- Laboratory of Molecular Biology, CCR, NCI, National Institutes of Health, Bethesda, MD, USA
| | - D Segal
- Cancer and Haematology Division, The Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Victoria, Australia
| | - N Simon
- Laboratory of Molecular Biology, CCR, NCI, National Institutes of Health, Bethesda, MD, USA
| | - RJ Kreitman
- Laboratory of Molecular Biology, CCR, NCI, National Institutes of Health, Bethesda, MD, USA
| | - D Huang
- Cancer and Haematology Division, The Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia
| | - DJ FitzGerald
- Laboratory of Molecular Biology, CCR, NCI, National Institutes of Health, Bethesda, MD, USA
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9
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Wolf P. BH3 Mimetics for the Treatment of Prostate Cancer. Front Pharmacol 2017; 8:557. [PMID: 28868037 PMCID: PMC5563364 DOI: 10.3389/fphar.2017.00557] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 08/07/2017] [Indexed: 12/11/2022] Open
Abstract
Despite improved diagnostic and therapeutic intervention, advanced prostate cancer (PC) remains incurable. The acquired resistance of PC cells to current treatment protocols has been traced to apoptosis resistance based on the upregulation of anti-apoptotic proteins of the Bcl-2 family. The use of BH3 mimetics, mimicking pro-apoptotic activator or sensitizer proteins of the intrinsic apoptotic pathway, is therefore a promising treatment strategy. The present review gives an overview of preclinical and clinical studies with pan- and specific BH3 mimetics as sensitizers for cell death and gives an outlook how they could be effectively used for the therapy of advanced PC in future.
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Affiliation(s)
- Philipp Wolf
- Department of Urology, Medical Center - University of Freiburg, Faculty of Medicine, University of FreiburgFreiburg, Germany
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10
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Antignani A, Mathews Griner L, Guha R, Simon N, Pasetto M, Keller J, Huang M, Angelus E, Pastan I, Ferrer M, FitzGerald DJ, Thomas CJ. Chemical Screens Identify Drugs that Enhance or Mitigate Cellular Responses to Antibody-Toxin Fusion Proteins. PLoS One 2016; 11:e0161415. [PMID: 27556570 PMCID: PMC4996465 DOI: 10.1371/journal.pone.0161415] [Citation(s) in RCA: 7] [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: 06/09/2016] [Accepted: 08/04/2016] [Indexed: 01/03/2023] Open
Abstract
The intersection of small molecular weight drugs and antibody-based therapeutics is rarely studied in large scale. Both types of agents are currently part of the cancer armamentarium. However, very little is known about how to combine them in optimal ways. Immunotoxins are antibody-toxin gene fusion proteins engineered to target cancer cells via antibody binding to surface antigens. For fusion proteins derived from Pseudomonas exotoxin (PE), potency relies on the enzymatic domain of the toxin which catalyzes the ADP-ribosylation of EF2 causing inhibition of protein synthesis leading to cell death. Candidate immunotoxins have demonstrated clear value in clinical trials but generally have not been curative as single agents. Therefore we undertook three screens to discover effective combinations that could act synergistically. From the MIPE-3 library of compounds we identified various enhancers of immunotoxin action and at least one major class of inhibitor. Follow-up experiments confirmed the screening data and suggested that immunotoxins when administered with everolimus or nilotinib exhibit favorable combinatory activity and would be candidates for preclinical development. Mechanistic studies revealed that everolimus-immunotoxin combinations acted synergistically on elements of the protein synthetic machinery, including S61 kinase and 4E-BP1 of the mTORC1 pathway. Conversely, PARP inhibitors antagonized immunotoxins and also blocked the toxicity due to native ADP-ribosylating toxins. Thus, our goal of investigating a chemical library was justified based on the identification of several approved compounds that could be developed preclinically as ‘enhancers’ and at least one class of mitigator to be avoided.
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Affiliation(s)
- Antonella Antignani
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892–4264, United States of America
| | - Lesley Mathews Griner
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland, 20850, United States of America
| | - Rajarshi Guha
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland, 20850, United States of America
| | - Nathan Simon
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892–4264, United States of America
| | - Matteo Pasetto
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892–4264, United States of America
| | - Jonathan Keller
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland, 20850, United States of America
| | - Manjie Huang
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892–4264, United States of America
| | - Evan Angelus
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892–4264, United States of America
| | - Ira Pastan
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892–4264, United States of America
| | - Marc Ferrer
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland, 20850, United States of America
| | - David J. FitzGerald
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892–4264, United States of America
- * E-mail: (DF); (CJT)
| | - Craig J. Thomas
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland, 20850, United States of America
- * E-mail: (DF); (CJT)
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11
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Zhang YF, Phung Y, Gao W, Kawa S, Hassan R, Pastan I, Ho M. New high affinity monoclonal antibodies recognize non-overlapping epitopes on mesothelin for monitoring and treating mesothelioma. Sci Rep 2015; 5:9928. [PMID: 25996440 PMCID: PMC4440525 DOI: 10.1038/srep09928] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 03/23/2015] [Indexed: 12/17/2022] Open
Abstract
Mesothelin is an emerging cell surface target in mesothelioma and other solid tumors. Most antibody drug candidates recognize highly immunogenic Region I (296–390) on mesothelin. Here, we report a group of high-affinity non-Region I rabbit monoclonal antibodies. These antibodies do not compete for mesothelin binding with the immunotoxin SS1P that binds Region I of mesothelin. One pair of antibodies (YP218 and YP223) is suitable to detect soluble mesothelin in a sandwich ELISA with high sensitivity. The new assay can also be used to measure serum mesothelin concentration in mesothelioma patients, indicating its potential use for monitoring patients treated with current antibody therapies targeting Region I. The antibodies are highly specific and sensitive in immunostaining of mesothelioma. To explore their use in tumor therapy, we have generated the immunotoxins based on the Fv of these antibodies. One immunotoxin (YP218 Fv-PE38) exhibits potent anti-tumor cytotoxicity towards primary mesothelioma cell lines in vitro and an NCI-H226 xenograft tumor in mice. Furthermore, we have engineered a humanized YP218 Fv that retains full binding affinity for mesothelin-expressing cancer cells. In conclusion, with their unique binding properties, these antibodies may be promising candidates for monitoring and treating mesothelioma and other mesothelin-expressing cancers.
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Affiliation(s)
- Yi-Fan Zhang
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, Bethesda, Bethesda, MD 20892, United States
| | - Yen Phung
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, Bethesda, Bethesda, MD 20892, United States
| | - Wei Gao
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, Bethesda, Bethesda, MD 20892, United States
| | - Seiji Kawa
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, Bethesda, Bethesda, MD 20892, United States
| | - Raffit Hassan
- Thoracic and Gastrointestinal Oncology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, United States
| | - Ira Pastan
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, Bethesda, Bethesda, MD 20892, United States
| | - Mitchell Ho
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, Bethesda, Bethesda, MD 20892, United States
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Hollevoet K, Mason-Osann E, Müller F, Pastan I. Methylation-associated partial down-regulation of mesothelin causes resistance to anti-mesothelin immunotoxins in a pancreatic cancer cell line. PLoS One 2015; 10:e0122462. [PMID: 25803818 PMCID: PMC4372481 DOI: 10.1371/journal.pone.0122462] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 02/17/2015] [Indexed: 11/19/2022] Open
Abstract
Anti-mesothelin Pseudomonas exotoxin A-based recombinant immunotoxins (RITs) present a potential treatment modality for pancreatic ductal adenocarcinoma (PDAC). To study mechanisms of resistance, the sensitive PDAC cell line KLM-1 was intermittently exposed to the anti-mesothelin SS1-LR-GGS RIT. Surviving cells were resistant to various anti-mesothelin RITs (IC50s >1 μg/ml), including the novel de-immunized RG7787. These resistant KLM-1-R cells were equally sensitive to the anti-CD71 HB21(Fv)-PE40 RIT as KLM-1, indicating resistance was specific to anti-mesothelin RITs. Mesothelin gene expression was partially down-regulated in KLM-1-R, resulting in 5-fold lower surface protein levels and decreased cellular uptake of RG7787 compared to KLM-1. Bisulfite sequencing analysis found that the mesothelin promoter region was significantly more methylated in KLM-1-R (59 ± 3.6%) compared to KLM-1 (41 ± 4.8%), indicating hypermethylation as a mechanism of mesothelin downregulation. The DNA methyltransferase inhibitor 5-azacytidine restored original mesothelin surface expression to more than half in KLM-1-R and increased sensitivity to RG7787 (IC50 = 722.4 ± 232.6 ng/ml), although cells remained significantly less sensitive compared to parental KLM-1 cells (IC50 = 4.41 ± 0.38 ng/ml). Mesothelin cDNA introduction in KLM-1-R led to 5-fold higher surface protein levels and significantly higher RG7887 uptake compared to KLM-1. As a result, the original sensitivity to RG7787 was fully restored (IC50 = 4.49 ± 1.11 ng/ml). A significantly higher RG7787 uptake was thus required to reach the original cytotoxicity in resistant cells, hinting that intracellular RIT trafficking is also a limiting factor. RNA deep sequencing analysis of KLM-1 and KLM-1-R cells supported our experimental findings; compared to KLM-1, resistant cells displayed differential expression of genes linked to intracellular transport and an expression pattern that matched a more general hypermethylation status. In conclusion, resistance to anti-mesothelin RITs in KLM-1 is linked to a methylation-associated down-regulation of mesothelin, while aberrations in RIT trafficking could also play a role.
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Affiliation(s)
- Kevin Hollevoet
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, United States of America
- Laboratory for Therapeutic and Diagnostic Antibodies, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven University, Leuven, Belgium
| | - Emily Mason-Osann
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, United States of America
| | - Fabian Müller
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, United States of America
| | - Ira Pastan
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, United States of America
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Engineering therapeutic proteins for cell entry: the natural approach. Trends Biotechnol 2015; 33:163-71. [DOI: 10.1016/j.tibtech.2014.12.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Revised: 12/08/2014] [Accepted: 12/16/2014] [Indexed: 02/04/2023]
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Hollevoet K, Mason-Osann E, Liu XF, Imhof-Jung S, Niederfellner G, Pastan I. In vitro and in vivo activity of the low-immunogenic antimesothelin immunotoxin RG7787 in pancreatic cancer. Mol Cancer Ther 2014; 13:2040-9. [PMID: 24928849 DOI: 10.1158/1535-7163.mct-14-0089-t] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Pancreatic ductal adenocarcinoma (PDAC) has a dismal prognosis, and new therapies are needed. RG7787 is a novel low-immunogenic antimesothelin recombinant immunotoxin (RIT), engineered to overcome the limitations of SS1P, a RIT now in clinical trials. In vitro activity was evaluated on five established PDAC cell lines (KLM-1, AsPC-1, BxPC-3, Panc 3.014, and PK-1) and on PDAC cells directly established from a patient tumor (GUMC108). RG7787 had subnanomolar IC50s in most cell lines, and was significantly more active than SS1P in GUMC108, KLM-1, and Panc 3.014 cells. GUMC108 was most sensitive, with RG7787 killing >99% of the cells. In a subcutaneous KLM-1 xenograft mouse model, two cycles of 3 × 2.5 mg/kg RG7787 QOD combined with two cycles of 1 × 50 mg/kg paclitaxel induced near-complete responses, with all tumors regressing below 5 mm(3) within 30 days after therapy was initiated (>95% decrease) and no significant growth increase for at least another 3 weeks. RG7787 alone gave limited but significant regressions and paclitaxel by itself arrested tumor growth. Quantifying the uptake of Alexa Fluor 647-labeled RG7787 in tumors showed that the RIT reached only 45% of KLM-1 cells, accounting in part for the limited responses. Paclitaxel did not improve RG7787 uptake, which thus cannot explain the beneficial effect of the combination therapy. In conclusion, RG7787 has high cytotoxic activity on PDAC cell lines as well as on primary patient cells. In vivo, this novel RIT gives durable near-complete tumor responses when combined with paclitaxel. RG7787 merits further evaluation for the treatment of PDAC.
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Affiliation(s)
- Kevin Hollevoet
- Laboratory of Molecular Biology, Center for Cancer Research, NCI, NIH, Bethesda, Maryland; Laboratory for Therapeutic and Diagnostic Antibodies, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium; and
| | - Emily Mason-Osann
- Laboratory of Molecular Biology, Center for Cancer Research, NCI, NIH, Bethesda, Maryland
| | - Xiu-fen Liu
- Laboratory of Molecular Biology, Center for Cancer Research, NCI, NIH, Bethesda, Maryland
| | - Sabine Imhof-Jung
- Pharmaceutical Research and Early Development (pRED), Roche Innovation Center Penzberg, Germany
| | - Gerhard Niederfellner
- Pharmaceutical Research and Early Development (pRED), Roche Innovation Center Penzberg, Germany
| | - Ira Pastan
- Laboratory of Molecular Biology, Center for Cancer Research, NCI, NIH, Bethesda, Maryland;
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