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Kur IM, Weigert A. Phosphatidylserine externalization as immune checkpoint in cancer. Pflugers Arch 2024:10.1007/s00424-024-02948-7. [PMID: 38573347 DOI: 10.1007/s00424-024-02948-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Revised: 03/13/2024] [Accepted: 03/16/2024] [Indexed: 04/05/2024]
Abstract
Cancer is the second leading cause of mortality worldwide. Despite recent advances in cancer treatment including immunotherapy with immune checkpoint inhibitors, new unconventional biomarkers and targets for the detection, prognosis, and treatment of cancer are still in high demand. Tumor cells are characterized by mutations that allow their unlimited growth, program their local microenvironment to support tumor growth, and spread towards distant sites. While a major focus has been on altered tumor genomes and proteomes, crucial signaling molecules such as lipids have been underappreciated. One of these molecules is the membrane phospholipid phosphatidylserine (PS) that is usually found at cytosolic surfaces of cellular membranes but can be rapidly and massively shuttled to the extracellular leaflet of the plasma membrane during apoptosis to serve as a limiting factor for immune responses. These immunosuppressive interactions are exploited by tumor cells to evade the immune system. In this review, we describe mechanisms of immune regulation in tumors, discuss if PS may constitute an inhibitory immune checkpoint, and describe current and future strategies for targeting PS to reactivate the tumor-associated immune system.
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Affiliation(s)
- Ivan-Maximiliano Kur
- Faculty of Medicine, Institute of Biochemistry I, Goethe-University Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany
| | - Andreas Weigert
- Faculty of Medicine, Institute of Biochemistry I, Goethe-University Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany.
- Frankfurt Cancer Institute, Goethe-University Frankfurt, 60596, Frankfurt, Germany.
- German Cancer Consortium (DKTK), Partner Site, Frankfurt, Germany.
- Cardiopulmonary Institute (CPI), 60590, Frankfurt, Germany.
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2
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Lev B, Chennath M, Cranfield CG, Cornelius F, Allen TW, Clarke RJ. Involvement of the alpha-subunit N-terminus in the mechanism of the Na +,K +-ATPase. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2023; 1870:119539. [PMID: 37479188 DOI: 10.1016/j.bbamcr.2023.119539] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 06/26/2023] [Accepted: 07/10/2023] [Indexed: 07/23/2023]
Abstract
Previous studies have shown that cytoplasmic K+ release and the associated E2 → E1 conformational change of the Na+,K+-ATPase is a major rate-determining step of the enzyme's ion pumping cycle and hence a prime site of acute regulatory intervention. From the ionic strength dependence of the enzyme's distribution between the E2 and E1 states, it has also been found that E2 is stabilized by an electrostatic attraction. Any disruption of this electrostatic attraction would, thus, have profound effects on the rate of ion pumping. The aim of this paper is to identify the location of this interaction. Using enhanced-sampling molecular dynamics simulations with a predicted N-terminal structure added to the X-ray crystal structure of the Na+,K+-ATPase, a previously postulated salt bridge between Lys32 and Glu233 (rat sequence numbering) of the enzyme's α-subunit can be excluded. The residues never approach closely enough to form a salt bridge. In contrast, strong interactions with anionic lipid head groups were seen. To investigate the possibility of a protein-lipid interaction experimentally, the surface charge density of Na+,K+-ATPase-containing membrane fragments was estimated from zeta potential measurements to be 0.019 (± 0.001) C m-2. This is in good agreement with the charge density previously determined to be responsible for stabilization of the E2 state of 0.023 (± 0.009) C m-2 and the membrane charge density estimated here from published electron-microscopic images of 0.018C m-2. The results are, therefore, consistent with an interaction of the Na+,K+-ATPase α-subunit N-terminus with negatively-charged lipid head groups of the neighbouring cytoplasmic membrane surface as the origin of the electrostatic interaction stabilising the E2 state.
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Affiliation(s)
- B Lev
- School of Science, RMIT University, Melbourne, Vic, 3001, Australia
| | - M Chennath
- School of Life Sciences, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - C G Cranfield
- School of Life Sciences, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - F Cornelius
- Department of Biomedicine, University of Aarhus, DK-8000 Aarhus, C, Denmark
| | - T W Allen
- School of Science, RMIT University, Melbourne, Vic, 3001, Australia
| | - R J Clarke
- School of Chemistry, University of Sydney, Sydney, NSW 2006, Australia; The University of Sydney Nano Institute, Sydney, NSW 2006, Australia.
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3
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Ly KI, Richardson LG, Liu M, Muzikansky A, Cardona J, Lou K, Beers AL, Chang K, Brown JM, Ma X, Reardon DA, Arrillaga-Romany IC, Forst DA, Jordan JT, Lee EQ, Dietrich J, Nayak L, Wen PY, Chukwueke U, Giobbie-Hurder A, Choi BD, Batchelor TT, Kalpathy-Cramer J, Curry WT, Gerstner ER. Bavituximab Decreases Immunosuppressive Myeloid-Derived Suppressor Cells in Newly Diagnosed Glioblastoma Patients. Clin Cancer Res 2023; 29:3017-3025. [PMID: 37327319 DOI: 10.1158/1078-0432.ccr-23-0203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 03/29/2023] [Accepted: 06/13/2023] [Indexed: 06/18/2023]
Abstract
PURPOSE We evaluated the efficacy of bavituximab-a mAb with anti-angiogenic and immunomodulatory properties-in newly diagnosed patients with glioblastoma (GBM) who also received radiotherapy and temozolomide. Perfusion MRI and myeloid-related gene transcription and inflammatory infiltrates in pre-and post-treatment tumor specimens were studied to evaluate on-target effects (NCT03139916). PATIENTS AND METHODS Thirty-three adults with IDH--wild-type GBM received 6 weeks of concurrent chemoradiotherapy, followed by 6 cycles of temozolomide (C1-C6). Bavituximab was given weekly, starting week 1 of chemoradiotherapy, for at least 18 weeks. The primary endpoint was proportion of patients alive at 12 months (OS-12). The null hypothesis would be rejected if OS-12 was ≥72%. Relative cerebral blood flow (rCBF) and vascular permeability (Ktrans) were calculated from perfusion MRIs. Peripheral blood mononuclear cells and tumor tissue were analyzed pre-treatment and at disease progression using RNA transcriptomics and multispectral immunofluorescence for myeloid-derived suppressor cells (MDSC) and macrophages. RESULTS The study met its primary endpoint with an OS-12 of 73% (95% confidence interval, 59%-90%). Decreased pre-C1 rCBF (HR, 4.63; P = 0.029) and increased pre-C1 Ktrans were associated with improved overall survival (HR, 0.09; P = 0.005). Pre-treatment overexpression of myeloid-related genes in tumor tissue was associated with longer survival. Post-treatment tumor specimens contained fewer immunosuppressive MDSCs (P = 0.01). CONCLUSIONS Bavituximab has activity in newly diagnosed GBM and resulted in on-target depletion of intratumoral immunosuppressive MDSCs. Elevated pre-treatment expression of myeloid-related transcripts in GBM may predict response to bavituximab.
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Affiliation(s)
- K Ina Ly
- Stephen E. and Catherine Pappas Center for Neuro-Oncology Massachusetts General Hospital Cancer Center, Boston, Massachusetts
| | - Leland G Richardson
- Department of Neurosurgery Massachusetts General Hospital, Boston, Massachusetts
| | - Mofei Liu
- Division of Biostatistics, Department of Data Sciences, Dana-Farber Cancer Institute, Boston, Massachusetts
| | - Alona Muzikansky
- Department of Biostatistics Massachusetts General Hospital Cancer Center, Boston, Massachusetts
| | - Jonathan Cardona
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, Massachusetts
| | - Kevin Lou
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, Massachusetts
| | - Andrew L Beers
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, Massachusetts
| | - Ken Chang
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, Massachusetts
- Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York
| | - James M Brown
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, Massachusetts
| | - Xiaoyue Ma
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, Massachusetts
| | - David A Reardon
- Center for Neuro-Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts
| | - Isabel C Arrillaga-Romany
- Stephen E. and Catherine Pappas Center for Neuro-Oncology Massachusetts General Hospital Cancer Center, Boston, Massachusetts
| | - Deborah A Forst
- Stephen E. and Catherine Pappas Center for Neuro-Oncology Massachusetts General Hospital Cancer Center, Boston, Massachusetts
| | - Justin T Jordan
- Stephen E. and Catherine Pappas Center for Neuro-Oncology Massachusetts General Hospital Cancer Center, Boston, Massachusetts
| | - Eudocia Q Lee
- Center for Neuro-Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts
| | - Jorg Dietrich
- Stephen E. and Catherine Pappas Center for Neuro-Oncology Massachusetts General Hospital Cancer Center, Boston, Massachusetts
| | - Lakshmi Nayak
- Center for Neuro-Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts
| | - Patrick Y Wen
- Center for Neuro-Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts
| | - Ugonma Chukwueke
- Center for Neuro-Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts
| | - Anita Giobbie-Hurder
- Division of Biostatistics, Department of Data Sciences, Dana-Farber Cancer Institute, Boston, Massachusetts
| | - Bryan D Choi
- Department of Neurosurgery Massachusetts General Hospital, Boston, Massachusetts
| | - Tracy T Batchelor
- Department of Neurology, Brigham and Women's Hospital, Boston, Massachusetts
| | - Jayashree Kalpathy-Cramer
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, Massachusetts
| | - William T Curry
- Department of Neurosurgery Massachusetts General Hospital, Boston, Massachusetts
| | - Elizabeth R Gerstner
- Stephen E. and Catherine Pappas Center for Neuro-Oncology Massachusetts General Hospital Cancer Center, Boston, Massachusetts
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, Massachusetts
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In Model, In Vitro and In Vivo Killing Efficacy of Antitumor Peptide RDP22 on MUG-Mel2, a Patient Derived Cell Line of an Aggressive Melanoma Metastasis. Biomedicines 2022; 10:biomedicines10112961. [PMID: 36428530 PMCID: PMC9687695 DOI: 10.3390/biomedicines10112961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 11/07/2022] [Accepted: 11/14/2022] [Indexed: 11/19/2022] Open
Abstract
The host defense derived peptide was assessed in different model systems with increasing complexity employing the highly aggressive NRAS mutated melanoma metastases cell line MUG-Mel2. Amongst others, fluorescence microscopy and spectroscopy, as well as cell death studies were applied for liposomal, 2D and 3D in vitro models including tumor spheroids without or within skin models and in vivo mouse xenografts. Summarized, MUG-Mel2 cells were shown to significantly expose the negatively charged lipid phosphatidylserine on their plasma membranes, showing they are successfully targeted by RDP22. The peptide was able to induce cell death in MUG-Mel2 2D and 3D cultures, where it was able to kill tumor cells even inside the core of tumor spheroids or inside a melanoma organotypic model. In vitro studies indicated cell death by apoptosis upon peptide treatment with an LC50 of 8.5 µM and seven-fold specificity for the melanoma cell line MUG-Mel2 over normal dermal fibroblasts. In vivo studies in mice xenografts revealed effective tumor regression upon intratumoral peptide injection, indicated by the strong clearance of pigmented tumor cells and tremendous reduction in tumor size and proliferation, which was determined histologically. The peptide RDP22 has clearly shown high potential against the melanoma cell line MUG-Mel2 in vitro and in vivo.
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Shahin K, Zhang L, Mehraban MH, Collard JM, Hedayatkhah A, Mansoorianfar M, Soleimani-Delfan A, Wang R. Clinical and experimental bacteriophage studies: Recommendations for possible approaches for standing against SARS-CoV-2. Microb Pathog 2022; 164:105442. [PMID: 35151823 PMCID: PMC8830156 DOI: 10.1016/j.micpath.2022.105442] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 02/05/2022] [Accepted: 02/07/2022] [Indexed: 12/23/2022]
Abstract
In 2019, the world faced a serious health challenge, the rapid spreading of a life-threatening viral pneumonia, coronavirus disease 2019 (COVID-19) caused by a betacoronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). As of January 2022 WHO statistics shows more than 5.6 million death and about 350 million infection by SARS-CoV-2. One of the life threatening aspects of COVID-19 is secondary infections and reduced efficacy of antibiotics against them. Since the beginning of COVID-19 many researches have been done on identification, treatment, and vaccine development. Bacterial viruses (bacteriophages) could offer novel approaches to detect, treat and control COVID-19. Phage therapy and in particular using phage cocktails can be used to control or eliminate the bacterial pathogen as an alternative or complementary therapeutic agent. At the same time, phage interaction with the host immune system can regulate the inflammatory response. In addition, phage display and engineered synthetic phages can be utilized to develop new vaccines and antibodies, stimulate the immune system, and elicit a rapid and well-appropriate defense response. The emergence of SARS-CoV-2 new variants like delta and omicron has proved the urgent need for precise, efficient and novel approaches for vaccine development and virus detection techniques in which bacteriophages may be one of the plausible solutions. Therefore, phages with similar morphology and/or genetic content to that of coronaviruses can be used for ecological and epidemiological modeling of SARS-CoV-2 behavior and future generations of coronavirus, and in general new viral pathogens. This article is a comprehensive review/perspective of potential applications of bacteriophages in the fight against the present pandemic and the post-COVID era.
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Zhang J, Dai Z, Yan C, Wang D, Tang D. Blocking antibody-mediated phosphatidylserine enhances cancer immunotherapy. J Cancer Res Clin Oncol 2021; 147:3639-3651. [PMID: 34499223 DOI: 10.1007/s00432-021-03792-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 09/03/2021] [Indexed: 02/07/2023]
Abstract
Cancer immunotherapy is a major breakthrough in tumor therapy and has been used in monotherapy or combination therapy. However, it has been associated with poor immune tolerance in some patients or immune-related adverse events. Therefore, ideal and reliable tumor elimination strategies are urgently needed to overcome these shortcomings. Phosphatidylserine (PS) is a negatively charged phospholipid, usually present in the inner lobules of eukaryotic cell membranes. Under certain physiological or pathological conditions, PS may be exposed on the outer leaflets of apoptotic cells serving as recognition signals by phagocytes and modulating the immune response. On the contrary, increased exposure of PS in the tumor microenvironment can significantly antagonize the body's anti-tumor immunity, thereby promoting tumor growth and metastasis. During radiotherapy and chemotherapy, PS-mediated immunosuppression increases the PS levels in necrotic tissue in the tumor microenvironment, further suppressing tumor immunity. PS-targeted therapy is a promising strategy in cancer immunotherapy. It inhibits tumor growth and improves the anti-tumor activity of immune checkpoint inhibitors. A comprehensive understanding of the mechanism of PS-targeted therapy opens up a new perspective for future cancer immunotherapies.
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Affiliation(s)
- Jie Zhang
- Clinical Medical College, Yangzhou University, Yangzhou, Jiangsu Province, China
| | - Zhujiang Dai
- Department of Colorectal Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200092, China
| | - Cheng Yan
- Dalian Medical University, Dalian, China
| | - Daorong Wang
- Department of General Surgery, Institute of General Surgery, Northern Jiangsu Province Hospital, Clinical Medical College, Yangzhou University, Yangzhou, 225001, People's Republic of China
| | - Dong Tang
- Department of General Surgery, Institute of General Surgery, Northern Jiangsu Province Hospital, Clinical Medical College, Yangzhou University, Yangzhou, 225001, People's Republic of China.
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Galluzzi L, Vacchelli E, Fridman WH, Galon J, Sautès-Fridman C, Tartour E, Zucman-Rossi J, Zitvogel L, Kroemer G. Trial Watch: Monoclonal antibodies in cancer therapy. Oncoimmunology 2021; 1:28-37. [PMID: 22720209 DOI: 10.4161/onci.1.1.17938] [Citation(s) in RCA: 79] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Since the advent of hybridoma technology, dating back to 1975, monoclonal antibodies have become an irreplaceable diagnostic and therapeutic tool for a wide array of human diseases. During the last 15 years, several monoclonal antibodies (mAbs) have been approved by FDA for cancer therapy. These mAbs are designed to (1) activate the immune system against tumor cells, (2) inhibit cancer cell-intrinsic signaling pathways, (3) bring toxins in the close proximity of cancer cells, or (4) interfere with the tumor-stroma interaction. More recently, major efforts have been made for the development of immunostimulatory mAbs that either enhance cancer-directed immune responses or limit tumor- (or therapy-) driven immunosuppression. Some of these antibodies, which are thought to facilitate tumor eradication by initiating or sustaining a tumor-specific immune response, have already entered clinical trials. In this Trial Watch, we will review and discuss the clinical progress of the most important mAbs that are have entered clinical trials after January 2008.
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Affiliation(s)
- Lorenzo Galluzzi
- INSERM, U848; Villejuif, France ; Institut Gustave Roussy; Villejuif, France ; Université Paris-Sud/Paris XI; Le Kremlin-Bicêtre, France
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8
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Targeting Phosphatidylserine Enhances the Anti-tumor Response to Tumor-Directed Radiation Therapy in a Preclinical Model of Melanoma. Cell Rep 2021; 34:108620. [PMID: 33440157 PMCID: PMC8100747 DOI: 10.1016/j.celrep.2020.108620] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 06/23/2020] [Accepted: 12/18/2020] [Indexed: 12/27/2022] Open
Abstract
Phosphatidylserine (PS) is exposed on the surface of apoptotic cells and is known to promote immunosuppressive signals in the tumor microenvironment (TME). Antibodies that block PS interaction with its receptors have been shown to repolarize the TME into a proinflammatory state. Radiation therapy (RT) is an effective focal treatment of isolated solid tumors but is less effective at controlling metastatic cancers. We found that tumor-directed RT caused an increase in expression of PS on the surface of viable immune infiltrates in mouse B16 melanoma. We hypothesize that PS expression on immune cells may provide negative feedback to immune cells in the TME. Treatment with an antibody that targets PS (mch1N11) enhanced the anti-tumor efficacy of tumor-directed RT and improved overall survival. This combination led to an increase in proinflammatory tumor-associated macrophages. The addition of anti-PD-1 to RT and mch1N11 led to even greater anti-tumor efficacy and overall survival. We found increased PS expression on several immune subsets in the blood of patients with metastatic melanoma after receiving tumor-directed RT. These findings highlight the potential of combining PS targeting with RT and PD-1 pathway blockade to improve outcomes in patients with advanced-stage cancers. Budhu et al. show that tumor-directed irradiation of murine B16 melanoma causes an increase in PS on the surface of infiltrating immune cells. Blocking PS and RT improves the anti-tumor efficacy and overall survival, which can be further improved with the addition of anti-PD-1. Melanoma patients exhibit increased PS on their PBMCs after RT.
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9
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Gadiyar V, Lahey KC, Calianese D, Devoe C, Mehta D, Bono K, Desind S, Davra V, Birge RB. Cell Death in the Tumor Microenvironment: Implications for Cancer Immunotherapy. Cells 2020; 9:cells9102207. [PMID: 33003477 PMCID: PMC7599747 DOI: 10.3390/cells9102207] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 09/26/2020] [Accepted: 09/26/2020] [Indexed: 02/06/2023] Open
Abstract
The physiological fate of cells that die by apoptosis is their prompt and efficient removal by efferocytosis. During these processes, apoptotic cells release intracellular constituents that include purine nucleotides, lysophosphatidylcholine (LPC), and Sphingosine-1-phosphate (S1P) that induce migration and chemo-attraction of phagocytes as well as mitogens and extracellular membrane-bound vesicles that contribute to apoptosis-induced compensatory proliferation and alteration of the extracellular matrix and the vascular network. Additionally, during efferocytosis, phagocytic cells produce a number of anti-inflammatory and resolving factors, and, together with apoptotic cells, efferocytic events have a homeostatic function that regulates tissue repair. These homeostatic functions are dysregulated in cancers, where, aforementioned events, if not properly controlled, can lead to cancer progression and immune escape. Here, we summarize evidence that apoptosis and efferocytosis are exploited in cancer, as well as discuss current translation and clinical efforts to harness signals from dying cells into therapeutic strategies.
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Seif F, Sharifi L, Khoshmirsafa M, Mojibi Y, Mohsenzadegan M. A Review of Preclinical Experiments Toward Targeting M2 Macrophages in Prostate Cancer. Curr Drug Targets 2020; 20:789-798. [PMID: 30674255 DOI: 10.2174/1389450120666190123141553] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 01/18/2019] [Accepted: 01/20/2019] [Indexed: 12/20/2022]
Abstract
Prostate cancer is malignant cancer leading to high mortality in the male population. The existence of suppressive cells referred to as tumor-associated macrophages (TAM) is a major obstacle in prostate cancer immunotherapy. TAMs contribute to the immunosuppressive microenvironment that promotes tumor growth and metastasis. In fact, they are main regulators of the complicated interactions between tumor and surrounding microenvironment. M2 macrophages, as a type of TAMs, are involved in the growth and progression of prostate cancer. Recently, they have gained remarkable importance as therapeutic candidates for solid tumors. In this review, we will discuss the roles of M2 macrophages and worth of their potential targeting in prostate cancer treatment. In the following, we will introduce important factors resulting in M2 macrophage promotion and also experimental therapeutic agents that may cause the inhibition of prostate cancer tumor growth.
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Affiliation(s)
- Farhad Seif
- Department of Immunology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran.,Neuroscience Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Laleh Sharifi
- Uro-Oncology Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Majid Khoshmirsafa
- Department of Immunology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran.,Neuroscience Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Yasaman Mojibi
- Department of Medical Laboratory Science, Faculty of Allied Medical Sciences, Iran University of Medical Sciences, Tehran, Iran
| | - Monireh Mohsenzadegan
- Department of Medical Laboratory Science, Faculty of Allied Medical Sciences, Iran University of Medical Sciences, Tehran, Iran
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11
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Dayoub AS, Brekken RA. TIMs, TAMs, and PS- antibody targeting: implications for cancer immunotherapy. Cell Commun Signal 2020; 18:29. [PMID: 32087708 PMCID: PMC7036251 DOI: 10.1186/s12964-020-0521-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 01/29/2020] [Indexed: 02/07/2023] Open
Abstract
Immunotherapy for cancer is making impressive strides at improving survival of a subset of cancer patients. To increase the breadth of patients that benefit from immunotherapy, new strategies that combat the immunosuppressive microenvironment of tumors are needed. Phosphatidylserine (PS) signaling is exploited by tumors to enhance tumor immune evasion and thus strategies to inhibit PS-mediated immune suppression have potential to increase the efficacy of immunotherapy. PS is a membrane lipid that flips to the outer surface of the cell membrane during apoptosis and/or cell stress. Externalized PS can drive efferocytosis or engage PS receptors (PSRs) to promote local immune suppression. In the tumor microenvironment (TME) PS-mediated immune suppression is often termed apoptotic mimicry. Monoclonal antibodies (mAbs) targeting PS or PSRs have been developed and are in preclinical and clinical testing. The TIM (T-cell/transmembrane, immunoglobulin, and mucin) and TAM (Tyro3, AXL, and MerTK) family of receptors are PSRs that have been shown to drive PS-mediated immune suppression in tumors. This review will highlight the development of mAbs targeting PS, TIM-3 and the TAM receptors. Video Abstract
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Affiliation(s)
- Adam S Dayoub
- Division of Surgical Oncology, Department of Surgery, Hamon Center for Therapeutic Oncology Research, University of Texas Southwestern Medical Center, 6000 Harry Hines Blvd., Dallas, TX, 75390-8593, USA
| | - Rolf A Brekken
- Division of Surgical Oncology, Department of Surgery, Hamon Center for Therapeutic Oncology Research, University of Texas Southwestern Medical Center, 6000 Harry Hines Blvd., Dallas, TX, 75390-8593, USA. .,Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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12
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Nishimura S, Matsumori N. Chemical diversity and mode of action of natural products targeting lipids in the eukaryotic cell membrane. Nat Prod Rep 2020; 37:677-702. [PMID: 32022056 DOI: 10.1039/c9np00059c] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Covering: up to 2019Nature furnishes bioactive compounds (natural products) with complex chemical structures, yet with simple, sophisticated molecular mechanisms. When natural products exhibit their activities in cells or bodies, they first have to bind or react with a target molecule in/on the cell. The cell membrane is a major target for bioactive compounds. Recently, our understanding of the molecular mechanism of interactions between natural products and membrane lipids progressed with the aid of newly-developed analytical methods. New technology reconnects old compounds with membrane lipids, while new membrane-targeting molecules are being discovered through the screening for antimicrobial potential of natural products. This review article focuses on natural products that bind to eukaryotic membrane lipids, and includes clinically important molecules and key research tools. The chemical diversity of membrane-targeting natural products and the molecular basis of lipid recognition are described. The history of how their mechanism was unveiled, and how these natural products are used in research are also mentioned.
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Affiliation(s)
- Shinichi Nishimura
- Department of Biotechnology, Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Tokyo 113-8657, Japan.
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Ghosh Roy S. TAM receptors: A phosphatidylserine receptor family and its implications in viral infections. TAM RECEPTORS IN HEALTH AND DISEASE 2020; 357:81-122. [DOI: 10.1016/bs.ircmb.2020.09.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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14
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Virani NA, Hendrick A, Wu D, Southard B, Babb J, Liu H, Awasthi V, Harrison RG. Enhanced computed tomography imaging of breast cancer via phosphatidylserine targeted gold nanoparticles. Biomed Phys Eng Express 2019. [DOI: 10.1088/2057-1976/ab4d9b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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15
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Rustagi V, Udugamasooriya DG. Identification of side arm-modified DOTA scaffolds as multi-site binding ligands for cancer cells over normal cells. Bioorg Med Chem Lett 2019; 29:126619. [PMID: 31431362 DOI: 10.1016/j.bmcl.2019.08.023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2019] [Revised: 08/09/2019] [Accepted: 08/11/2019] [Indexed: 10/26/2022]
Abstract
The metal-chelated 1,4,7,10-tetraazacyclododecan-1,4,7,10-tetraacetic acid-tetraamide (DOTA) scaffold has been widely used as a contrast agent for diagnostic purposes in positron emission tomography (PET) and magnetic resonance imaging (MRI), but not as a biomarker targetable ligand. While the oxygen atoms at the stem of the four arms of the DOTA scaffold are needed for metal chelation, we previously introduced various physiochemical properties to extend these arms in a chemical library fashion to enhance the imaging contrast mechanism. We developed two such on-bead libraries, with 80 and 76 DOTA derivatives, where one arm was used to attach the DOTA scaffold onto resin beads and the other three arms were chemically modified. We now hypothesized that the chemical moieties used to modify these three arms can also recognize biomarkers on a cell surface. Therefore in this current study, we used such 76 derivatives of DOTA library to screen against HeLa cervical cancer cells. We found that two of the four 'hits' identified displayed higher binding towards HeLa cells than the unmodified parent DOTA. Furthermore, one of those 'hits' displayed better binding towards cervical and prostate cancer cells than lung and breast cancer cells and normal HBEC-3KT and RWPE1 cells. This indicates that this derivative can recognize a biomarker specific for certain types of cancer cells. If the compound has intrinsic activity, this can be used as a theranostic agent for real time therapy monitoring applications in the future. We believe that our DOTA derivative-based library approach can be applied to other types of cell and protein screens on various disease types in the future.
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Affiliation(s)
- Vineeta Rustagi
- Department of Pharmacological & Pharmaceutical Sciences, University of Houston, 4849 Calhoun Rd, Health Building 2, Room 7033, Houston, TX 77204-5037, USA
| | - D Gomika Udugamasooriya
- Department of Pharmacological & Pharmaceutical Sciences, University of Houston, 4849 Calhoun Rd, Health Building 2, Room 7033, Houston, TX 77204-5037, USA; Department of Cancer Systems Imaging, MD Anderson Cancer Center, 1881 East Road, Houston, TX 77030-4009, USA.
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16
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Mokdad AA, Zhu H, Beg MS, Arriaga Y, Dowell JE, Singal AG, Yopp AC. Efficacy and Safety of Bavituximab in Combination with Sorafenib in Advanced Hepatocellular Carcinoma: A Single-Arm, Open-Label, Phase II Clinical Trial. Target Oncol 2019; 14:541-550. [DOI: 10.1007/s11523-019-00663-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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17
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Liang Y, Besch-Williford C, Cook MT, Belenchia A, Brekken RA, Hyder SM. APR-246 alone and in combination with a phosphatidylserine-targeting antibody inhibits lung metastasis of human triple-negative breast cancer cells in nude mice. BREAST CANCER-TARGETS AND THERAPY 2019; 11:249-259. [PMID: 31534364 PMCID: PMC6681124 DOI: 10.2147/bctt.s208706] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 07/18/2019] [Indexed: 12/29/2022]
Abstract
Background Approximately 15–20% of all human breast cancers are classified as triple-negative because they lack estrogen and progesterone receptors and Her-2-neu, which are commonly targeted by chemotherapeutic drugs. New treatment strategies are therefore urgently needed to combat triple-negative breast cancers (TNBCs). Almost 80% of the triple-negative tumors express mutant p53 (mtp5), a functionally defective tumor suppressor protein. Whereas wild-type p53 (wtp53) promotes cell-cycle arrest and apoptosis and inhibits vascular endothelial growth factor-dependent angiogenesis, mtp53 fails to regulate these functions, resulting in tumor vascularization, growth, resistance to chemotherapy, and metastasis. Restoration of p53 function is therefore a promising drug-targeted strategy for suppressing TNBC metastasis. Methods APR-246 is a small-molecule drug that reactivates mtp53, thereby restoring p53 function. In this study, we sought to determine whether administration of APR-246, either alone or in combination with 2aG4, an antibody that targets phosphatidylserine residues on tumor blood vessels and disrupts tumor vasculature, effectively inhibits stem cell-like characteristics of tumor cells and migration in vitro, and metastasis of human mtp53-expressing TNBC cells to the lungs in mouse models. Results APR-246 reduced both the stem cell-like properties and migration of TNBC cells in vitro. In mouse models, administration of either APR-246 or 2aG4 reduced metastasis of TNBC cells to the lungs; a combination of the two diminished lung metastasis to the same extent as either agent alone. Combination treatment significantly reduced the incidence of lung metastasis compared either single agent alone. Conclusion Metastasis of human mtp53-expressing TNBC cells to the lungs of nude mice is inhibited by the treatment that combines activation of mtp53 with targeting of phosphatidylserine residues on tumor blood vessels. We contend therefore that our findings strongly support the use of combination treatment involving mtp53 activation and immunotherapy in patients with TNBC.
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Affiliation(s)
- Yayun Liang
- Department of Biomedical Sciences and Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO, USA
| | | | - Matthew T Cook
- Department of Biology, Washburn University, Topeka, KS, USA
| | - Anthony Belenchia
- Department of Nutrition and Exercise Physiology and Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO, USA
| | - Rolf A Brekken
- Hamon Center for Therapeutic Oncology Research and Department of Surgery, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Salman M Hyder
- Department of Biomedical Sciences and Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO, USA
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18
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Shin SA, Moon SY, Park D, Park JB, Lee CS. Apoptotic cell clearance in the tumor microenvironment: a potential cancer therapeutic target. Arch Pharm Res 2019; 42:658-671. [PMID: 31243646 DOI: 10.1007/s12272-019-01169-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 06/06/2019] [Indexed: 12/14/2022]
Abstract
Millions of cells in the human body undergo apoptosis not only under normal physiological conditions but also under pathological conditions such as infection or other diseases related to acute tissue injury. Swift apoptotic cell clearance is essential for tissue homeostasis. Defective clearance of dead cells is linked to pathogenesis of diseases such as inflammatory diseases, atherosclerosis, neurological disease, and cancer. Significance of apoptotic cell clearance has been emerging as an interesting field for disease treatment. Efficient apoptotic cell clearance plays an important role in reducing inflammation through the suppression of inappropriate inflammatory responses under healthy and diseased conditions. However, apoptotic cell clearance related to cancer pathogenesis is more complex in tumor microenvironments. Chronic inflammation resulting from the failure of apoptotic cell clearance can contribute to tumor progression. Conversely, tumor cells can exploit the anti-inflammatory effect of apoptotic cell clearance to generate an immunosuppressive tumor microenvironment. In this review, focus is on the current understanding of apoptotic cell clearance in the tumor microenvironment. Furthermore, we discuss how signaling molecules (PtdSer and PtdSer recognition receptor) mediating apoptotic cell clearance are aberrantly expressed in the tumor microenvironment and their current development state as potential therapeutic targets for clinical cancer therapy.
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Affiliation(s)
- Seong-Ah Shin
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Gyeongsang National University, 501 Jinju-daero, Jinju, Gyeongnam, 52828, Republic of Korea
| | - Sun Young Moon
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Gyeongsang National University, 501 Jinju-daero, Jinju, Gyeongnam, 52828, Republic of Korea
| | - Daeho Park
- School of Life Sciences and Aging Research Institute, Gwangju Institute of Science and Technology, Gwangju, 61005, Republic of Korea
| | - Jong Bae Park
- Specific Organs Cancer Branch, Research Institute and Hospital, National Cancer Center, Goyang, Gyeonggi, 10408, Republic of Korea.,Department of System Cancer Science, Graduate School of Cancer Science and Policy, National Cancer Center, Goyang, Gyeonggi, 10408, Republic of Korea
| | - Chang Sup Lee
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Gyeongsang National University, 501 Jinju-daero, Jinju, Gyeongnam, 52828, Republic of Korea.
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19
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Wang L, Habib AA, Mintz A, Li KC, Zhao D. Phosphatidylserine-Targeted Nanotheranostics for Brain Tumor Imaging and Therapeutic Potential. Mol Imaging 2018; 16:1536012117708722. [PMID: 28654387 PMCID: PMC5470144 DOI: 10.1177/1536012117708722] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Phosphatidylserine (PS), the most abundant anionic phospholipid in cell membrane, is strictly confined to the inner leaflet in normal cells. However, this PS asymmetry is found disruptive in many tumor vascular endothelial cells. We discuss the underlying mechanisms for PS asymmetry maintenance in normal cells and its loss in tumor cells. The specificity of PS exposure in tumor vasculature but not normal blood vessels may establish it a useful biomarker for cancer molecular imaging. Indeed, utilizing PS-targeting antibodies, multiple imaging probes have been developed and multimodal imaging data have shown their high tumor-selective targeting in various cancers. There is a critical need for improved diagnosis and therapy for brain tumors. We have recently established PS-targeted nanoplatforms, aiming to enhance delivery of imaging contrast agents across the blood-brain barrier to facilitate imaging of brain tumors. Advantages of using the nanodelivery system, in particular, lipid-based nanocarriers, are discussed here. We also describe our recent research interest in developing PS-targeted nanotheranostics for potential image-guided drug delivery to treat brain tumors.
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Affiliation(s)
- Lulu Wang
- 1 Department of Biomedical Engineering, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Amyn A Habib
- 2 Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA.,3 North Texas VA Medical Center, Dallas, TX, USA
| | - Akiva Mintz
- 4 Department of Cancer Biology, Wake Forest School of Medicine, Winston-Salem, NC, USA.,5 Department of Radiology, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - King C Li
- 4 Department of Cancer Biology, Wake Forest School of Medicine, Winston-Salem, NC, USA.,6 Clinical and Translational Science Institute, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Dawen Zhao
- 1 Department of Biomedical Engineering, Wake Forest School of Medicine, Winston-Salem, NC, USA.,3 North Texas VA Medical Center, Dallas, TX, USA
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20
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Liang Y, Mafuvadze B, Besch-Williford C, Hyder SM. A combination of p53-activating APR-246 and phosphatidylserine-targeting antibody potently inhibits tumor development in hormone-dependent mutant p53-expressing breast cancer xenografts. BREAST CANCER-TARGETS AND THERAPY 2018; 10:53-67. [PMID: 29606888 PMCID: PMC5868596 DOI: 10.2147/bctt.s156285] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Background Between 30 and 40% of human breast cancers express a defective tumor suppressor p53 gene. Wild-type p53 tumor suppressor protein promotes cell-cycle arrest and apoptosis and inhibits vascular endothelial growth factor-dependent angiogenesis, whereas mutant p53 protein (mtp53) lacks these functions, resulting in tumor cell survival and metastasis. Restoration of p53 function is therefore a promising drug-targeted strategy for combating mtp53-expressing breast cancer. Methods In this study, we sought to determine whether administration of APR-246, a small-molecule drug that restores p53 function, in combination with 2aG4, an antibody that targets phosphatidylserine residues on tumor blood vessels and disrupts tumor vasculature, effectively inhibits advanced hormone-dependent breast cancer tumor growth. Results APR-246 reduced cell viability in mtp53-expressing BT-474 and T47-D human breast cancer cells in vitro, and significantly induced apoptosis in a dose-dependent manner. However, APR-246 did not reduce cell viability in MCF-7 breast cancer cells, which express wild-type p53. We next examined APR-246's anti-tumor effects in vivo using BT-474 and T47-D tumor xenografts established in female nude mice. Tumor-bearing mice were treated with APR-246 and/or 2aG4 and tumor volume followed over time. Tumor growth was more effectively suppressed by combination treatment than by either agent alone, and combination therapy completely eradicated some tumors. Immunohistochemistry analysis of tumor tissue sections demonstrated that combination therapy more effectively induced apoptosis and reduced cell proliferation in tumor xenografts than either agent alone. Importantly, combination therapy dramatically reduced the density of blood vessels, which serve as the major route for tumor metastasis, in tumor xenografts compared with either agent alone. Conclusion Based on our findings, we contend that breast tumor growth might effectively be controlled by simultaneous targeting of mtp53 protein and tumor blood vessels in mtp53-expressing cancers.
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Affiliation(s)
- Yayun Liang
- Deparment of Biomedical Sciences and Dalton Cardiovascular Research Center, Columbia, MO, USA
| | - Benford Mafuvadze
- Deparment of Biomedical Sciences and Dalton Cardiovascular Research Center, Columbia, MO, USA
| | | | - Salman M Hyder
- Deparment of Biomedical Sciences and Dalton Cardiovascular Research Center, Columbia, MO, USA
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21
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Anti-CD73 and anti-OX40 immunotherapy coupled with a novel biocompatible enzyme prodrug system for the treatment of recurrent, metastatic ovarian cancer. Cancer Lett 2018; 425:174-182. [PMID: 29574275 DOI: 10.1016/j.canlet.2018.03.027] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 03/13/2018] [Accepted: 03/14/2018] [Indexed: 02/02/2023]
Abstract
Approximately 75% of ovarian cancer is diagnosed once metastasis to the peritoneal cavity has occurred. A large proportion of patients eventually develop platinum-resistive tumors, which are considered terminal. In order to provide an alternative a novel fusion protein, mCTH-ANXA5, has been developed for the treatment of recurrent, metastatic ovarian cancer. The fusion protein combines annexin V (ANXA5), an ovarian tumor and tumor vasculature targeting protein, with mutated cystathionine gamma-lyase (mCTH), an enzyme that converts selenomethionine (SeMet) into toxic methylselenol, which generates reactive oxygen species and eventual tumor cell death. In order to further enhance the therapeutic efficacy, anti-CD73 and anti-OX40 immunostimulants were combined with mCTH-ANXA5, resulting in an increase of survival by 100% from 12 to 24 days post-therapy and decrease tumor burden in mice with orthotopic metastatic ovarian cancer. Further evaluation of the combination therapy revealed a strong antibody-mediated immune response, and an increased infiltration of cytotoxic T-cells along with a decrease in tumor promoting immune cells. This study demonstrates the efficacy of a synergistic, multi-drug system by attacking the tumor as well as enlisting the body's own defense system to treat the patient.
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22
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Grilley-Olson JE, Weiss J, Ivanova A, Villaruz LC, Moore DT, Stinchcombe TE, Lee C, Shan JS, Socinski MA. Phase Ib Study of Bavituximab With Carboplatin and Pemetrexed in Chemotherapy-Naive Advanced Nonsquamous Non-Small-Cell Lung Cancer. Clin Lung Cancer 2018; 19:e481-e487. [PMID: 29631965 DOI: 10.1016/j.cllc.2018.03.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 02/08/2018] [Accepted: 03/10/2018] [Indexed: 10/17/2022]
Abstract
INTRODUCTION Bavituximab is an immunomodulatory chimeric monoclonal antibody that inhibits phosphatidylserine signaling, which promotes innate and adaptive immune responses. In this phase Ib trial we evaluated the safety, tolerability, and preliminary antitumor activity of pemetrexed, carboplatin, bavituximab in advanced non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS Patients with advanced nonsquamous NSCLC and performance status 0 or 1 were treated with pemetrexed 500 mg/m2 and carboplatin area under the curve 6 once every 3 weeks for up to 6 cycles, with concurrent bavituximab (0.3, 1, or 3 mg/kg) intravenously weekly, using a standard 3+3 design. At the maximum identified dose, additional patients were enrolled to further characterize the safety profile. The primary objective was to characterize the safety, determine the dose-limiting toxicities (DLTs), and establish the recommended phase II dose of bavituximab in combination with pemetrexed and carboplatin in incurable stage IV nonsquamous NSCLC. RESULTS Between March 29, 2011 and December 30, 2013, 26 patients were enrolled. Three patients each were enrolled into dose escalation cohorts of bavituximab (0.3, 1, and 3 mg/kg). Therapy was well tolerated with no DLTs, and toxicities were consistent with those expected from pemetrexed/carboplatin. Overall response was 28%, with a median progression-free and overall survival of 4.8 months and 12.2 months, respectively. CONCLUSION The combination of pemetrexed, carboplatin, bavituximab is well tolerated. However, with toxicities and preliminary efficacy signal similar to pemetrexed/carboplatin alone, further studies of bavituximab should focus on ways to enhance its immunomodulatory role.
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Affiliation(s)
- Juneko E Grilley-Olson
- Department of Medicine, Division of Hematology-Oncology, University of North Carolina, Chapel Hill, NC; Lineberger Cancer Center, University of North Carolina, Chapel Hill, NC.
| | - Jared Weiss
- Department of Medicine, Division of Hematology-Oncology, University of North Carolina, Chapel Hill, NC; Lineberger Cancer Center, University of North Carolina, Chapel Hill, NC
| | - Anastasia Ivanova
- Lineberger Cancer Center, University of North Carolina, Chapel Hill, NC; Department of Biostatistics, University of North Carolina, Chapel Hill, NC
| | | | - Dominic T Moore
- Lineberger Cancer Center, University of North Carolina, Chapel Hill, NC; Department of Biostatistics, University of North Carolina, Chapel Hill, NC
| | - Thomas E Stinchcombe
- Department of Medicine, Division of Hematology-Oncology, University of North Carolina, Chapel Hill, NC; Lineberger Cancer Center, University of North Carolina, Chapel Hill, NC
| | - Carrie Lee
- Department of Medicine, Division of Hematology-Oncology, University of North Carolina, Chapel Hill, NC; Lineberger Cancer Center, University of North Carolina, Chapel Hill, NC
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Rybczynska AA, Boersma HH, de Jong S, Gietema JA, Noordzij W, Dierckx RAJO, Elsinga PH, van Waarde A. Avenues to molecular imaging of dying cells: Focus on cancer. Med Res Rev 2018. [PMID: 29528513 PMCID: PMC6220832 DOI: 10.1002/med.21495] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Successful treatment of cancer patients requires balancing of the dose, timing, and type of therapeutic regimen. Detection of increased cell death may serve as a predictor of the eventual therapeutic success. Imaging of cell death may thus lead to early identification of treatment responders and nonresponders, and to “patient‐tailored therapy.” Cell death in organs and tissues of the human body can be visualized, using positron emission tomography or single‐photon emission computed tomography, although unsolved problems remain concerning target selection, tracer pharmacokinetics, target‐to‐nontarget ratio, and spatial and temporal resolution of the scans. Phosphatidylserine exposure by dying cells has been the most extensively studied imaging target. However, visualization of this process with radiolabeled Annexin A5 has not become routine in the clinical setting. Classification of death modes is no longer based only on cell morphology but also on biochemistry, and apoptosis is no longer found to be the preponderant mechanism of cell death after antitumor therapy, as was earlier believed. These conceptual changes have affected radiochemical efforts. Novel probes targeting changes in membrane permeability, cytoplasmic pH, mitochondrial membrane potential, or caspase activation have recently been explored. In this review, we discuss molecular changes in tumors which can be targeted to visualize cell death and we propose promising biomarkers for future exploration.
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Affiliation(s)
- Anna A Rybczynska
- Molecular Imaging Center, Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.,Department of Genetics, University of Groningen, Groningen, the Netherlands
| | - Hendrikus H Boersma
- Molecular Imaging Center, Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.,Department of Clinical Pharmacy & Pharmacology, University of Groningen, Groningen, the Netherlands
| | - Steven de Jong
- Department of Medical Oncology, University of Groningen, Groningen, the Netherlands
| | - Jourik A Gietema
- Department of Medical Oncology, University of Groningen, Groningen, the Netherlands
| | - Walter Noordzij
- Molecular Imaging Center, Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Rudi A J O Dierckx
- Molecular Imaging Center, Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.,Department of Nuclear Medicine, Ghent University, Ghent, Belgium
| | - Philip H Elsinga
- Molecular Imaging Center, Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Aren van Waarde
- Molecular Imaging Center, Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
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Antiphospholipid antibodies induce thrombosis by PP2A activation via apoER2-Dab2-SHC1 complex formation in endothelium. Blood 2018; 131:2097-2110. [PMID: 29500169 DOI: 10.1182/blood-2017-11-814681] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 02/23/2018] [Indexed: 01/10/2023] Open
Abstract
In the antiphospholipid syndrome (APS), antiphospholipid antibody (aPL) recognition of β2 glycoprotein I promotes thrombosis, and preclinical studies indicate that this is due to endothelial nitric oxide synthase (eNOS) antagonism via apolipoprotein E receptor 2 (apoER2)-dependent processes. How apoER2 molecularly links these events is unknown. Here, we show that, in endothelial cells, the apoER2 cytoplasmic tail serves as a scaffold for aPL-induced assembly and activation of the heterotrimeric protein phosphatase 2A (PP2A). Disabled-2 (Dab2) recruitment to the apoER2 NPXY motif promotes the activating L309 methylation of the PP2A catalytic subunit by leucine methyl transferase-1. Concurrently, Src homology domain-containing transforming protein 1 (SHC1) recruits the PP2A scaffolding subunit to the proline-rich apoER2 C terminus along with 2 distinct regulatory PP2A subunits that mediate inhibitory dephosphorylation of Akt and eNOS. In mice, the coupling of these processes in endothelium is demonstrated to underlie aPL-invoked thrombosis. By elucidating these intricacies in the pathogenesis of APS-related thrombosis, numerous potential new therapeutic targets have been identified.
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25
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Crittenden MR, Baird J, Friedman D, Savage T, Uhde L, Alice A, Cottam B, Young K, Newell P, Nguyen C, Bambina S, Kramer G, Akporiaye E, Malecka A, Jackson A, Gough MJ. Mertk on tumor macrophages is a therapeutic target to prevent tumor recurrence following radiation therapy. Oncotarget 2018; 7:78653-78666. [PMID: 27602953 PMCID: PMC5346667 DOI: 10.18632/oncotarget.11823] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2016] [Accepted: 08/25/2016] [Indexed: 12/19/2022] Open
Abstract
Radiation therapy provides a means to kill large numbers of cancer cells in a controlled location resulting in the release of tumor-specific antigens and endogenous adjuvants. However, by activating pathways involved in apoptotic cell recognition and phagocytosis, irradiated cancer cells engender suppressive phenotypes in macrophages. We demonstrate that the macrophage-specific phagocytic receptor, Mertk is upregulated in macrophages in the tumor following radiation therapy. Ligation of Mertk on macrophages results in anti-inflammatory cytokine responses via NF-kB p50 upregulation, which in turn limits tumor control following radiation therapy. We demonstrate that in immunogenic tumors, loss of Mertk is sufficient to permit tumor cure following radiation therapy. However, in poorly immunogenic tumors, TGFβ inhibition is also required to result in tumor cure following radiation therapy. These data demonstrate that Mertk is a highly specific target whose absence permits tumor control in combination with radiation therapy.
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Affiliation(s)
- Marka R Crittenden
- Earle A. Chiles Research Institute, Robert W. Franz Cancer Center, Providence Portland Medical Center, Portland OR, USA.,The Oregon Clinic, Portland OR, USA
| | - Jason Baird
- Earle A. Chiles Research Institute, Robert W. Franz Cancer Center, Providence Portland Medical Center, Portland OR, USA
| | - David Friedman
- Earle A. Chiles Research Institute, Robert W. Franz Cancer Center, Providence Portland Medical Center, Portland OR, USA
| | - Talicia Savage
- Earle A. Chiles Research Institute, Robert W. Franz Cancer Center, Providence Portland Medical Center, Portland OR, USA
| | - Lauren Uhde
- Earle A. Chiles Research Institute, Robert W. Franz Cancer Center, Providence Portland Medical Center, Portland OR, USA
| | - Alejandro Alice
- Earle A. Chiles Research Institute, Robert W. Franz Cancer Center, Providence Portland Medical Center, Portland OR, USA
| | - Benjamin Cottam
- Earle A. Chiles Research Institute, Robert W. Franz Cancer Center, Providence Portland Medical Center, Portland OR, USA
| | - Kristina Young
- Earle A. Chiles Research Institute, Robert W. Franz Cancer Center, Providence Portland Medical Center, Portland OR, USA.,The Oregon Clinic, Portland OR, USA
| | - Pippa Newell
- Earle A. Chiles Research Institute, Robert W. Franz Cancer Center, Providence Portland Medical Center, Portland OR, USA.,Providence Hepatobiliary and Pancreatic Cancer Program, Providence Portland Medical Center, Portland OR, USA
| | - Cynthia Nguyen
- Earle A. Chiles Research Institute, Robert W. Franz Cancer Center, Providence Portland Medical Center, Portland OR, USA
| | - Shelly Bambina
- Earle A. Chiles Research Institute, Robert W. Franz Cancer Center, Providence Portland Medical Center, Portland OR, USA
| | - Gwen Kramer
- Earle A. Chiles Research Institute, Robert W. Franz Cancer Center, Providence Portland Medical Center, Portland OR, USA
| | - Emmanuel Akporiaye
- Earle A. Chiles Research Institute, Robert W. Franz Cancer Center, Providence Portland Medical Center, Portland OR, USA
| | - Anna Malecka
- Host-Tumour Interactions Group, Division of Cancer and Stem Cells, University of Nottingham, UK
| | - Andrew Jackson
- Host-Tumour Interactions Group, Division of Cancer and Stem Cells, University of Nottingham, UK
| | - Michael J Gough
- Earle A. Chiles Research Institute, Robert W. Franz Cancer Center, Providence Portland Medical Center, Portland OR, USA
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Belzile O, Huang X, Gong J, Carlson J, Schroit AJ, Brekken RA, Freimark BD. Antibody targeting of phosphatidylserine for the detection and immunotherapy of cancer. Immunotargets Ther 2018; 7:1-14. [PMID: 29417044 PMCID: PMC5788995 DOI: 10.2147/itt.s134834] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Phosphatidylserine (PS) is a negatively charged phospholipid in all eukaryotic cells that is actively sequestered to the inner leaflet of the cell membrane. Exposure of PS on apoptotic cells is a normal physiological process that triggers their rapid removal by phagocytic engulfment under noninflammatory conditions via receptors primarily expressed on immune cells. PS is aberrantly exposed in the tumor microenvironment and contributes to the overall immunosuppressive signals that antagonize the development of local and systemic antitumor immune responses. PS-mediated immunosuppression in the tumor microenvironment is further exacerbated by chemotherapy and radiation treatments that result in increased levels of PS on dying cells and necrotic tissue. Antibodies targeting PS localize to tumors and block PS-mediated immunosuppression. Targeting exposed PS in the tumor microenvironment may be a novel approach to enhance immune responses to cancer.
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Affiliation(s)
- Olivier Belzile
- Hamon Center for Therapeutic Oncology Research, University of Texas Southwestern Medical Center, Dallas, TX
| | - Xianming Huang
- Department of Preclinical Research.,Department of Antibody Discovery, Peregrine Pharmaceuticals, Inc., Tustin, CA, USA
| | - Jian Gong
- Department of Preclinical Research.,Department of Antibody Discovery, Peregrine Pharmaceuticals, Inc., Tustin, CA, USA
| | - Jay Carlson
- Department of Preclinical Research.,Department of Antibody Discovery, Peregrine Pharmaceuticals, Inc., Tustin, CA, USA
| | - Alan J Schroit
- Hamon Center for Therapeutic Oncology Research, University of Texas Southwestern Medical Center, Dallas, TX
| | - Rolf A Brekken
- Hamon Center for Therapeutic Oncology Research, University of Texas Southwestern Medical Center, Dallas, TX
| | - Bruce D Freimark
- Department of Preclinical Research.,Department of Antibody Discovery, Peregrine Pharmaceuticals, Inc., Tustin, CA, USA
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27
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Zhang L, Habib AA, Zhao D. Phosphatidylserine-targeted liposome for enhanced glioma-selective imaging. Oncotarget 2018; 7:38693-38706. [PMID: 27231848 PMCID: PMC5122421 DOI: 10.18632/oncotarget.9584] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 04/28/2016] [Indexed: 12/31/2022] Open
Abstract
Phosphatidylserine (PS), which is normally intracellular, becomes exposed on the outer surface of viable endothelial cells (ECs) of tumor vasculature. Utilizing a PS-targeting antibody, we have recently established a PS-targeted liposomal (PS-L) nanoplatform that has demonstrated to be highly tumor-selective. Because of the vascular lumen-exposed PS that is immediately accessible without a need to penetrate the intact blood brain barrier (BBB), we hypothesize that the systemically administered PS-L binds specifically to tumor vascular ECs, becomes subsequently internalized into the cells and then enables its cargos to be efficiently delivered to glioma parenchyma. To test this, we exploited the dual MRI/optical imaging contrast agents-loaded PS-L and injected it intravenously into mice bearing intracranial U87 glioma. At 24 h, both in vivo optical imaging and MRI depicted enhanced tumor contrast, distinct from the surrounding normal brain. Intriguingly, longitudinal MRI revealed temporal and spatial intratumoral distribution of the PS-L by following MRI contrast changes, which appeared punctate in tumor periphery at an earlier time point (4 h), but became clustering and disseminated throughout the tumor at 24 h post injection. Importantly, glioma-targeting specificity of the PS-L was antigen specific, since a control probe of irrelevant specificity showed minimal accumulation in the glioma. Together, these results indicate that the PS-L nanoplatform enables the enhanced, glioma-targeted delivery of imaging contrast agents by crossing the tumor BBB efficiently, which may also serve as a useful nanoplatform for anti-glioma drugs.
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Affiliation(s)
- Liang Zhang
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Amyn A Habib
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center and the North Texas VA Medical Center, Dallas, TX, USA
| | - Dawen Zhao
- Department of Biomedical Engineering, Wake Forest School of Medicine, Winston Salem, NC, USA.,Department of Cancer Biology, Wake Forest School of Medicine, Winston Salem, NC, USA
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28
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Virani NA, Davis C, McKernan P, Hauser P, Hurst RE, Slaton J, Silvy RP, Resasco DE, Harrison RG. Phosphatidylserine targeted single-walled carbon nanotubes for photothermal ablation of bladder cancer. NANOTECHNOLOGY 2018; 29:035101. [PMID: 29160225 DOI: 10.1088/1361-6528/aa9c0c] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Bladder cancer has a 60%-70% recurrence rate most likely due to any residual tumour left behind after a transurethral resection (TUR). Failure to completely resect the cancer can lead to recurrence and progression into higher grade tumours with metastatic potential. We present here a novel therapy to treat superficial tumours with the potential to decrease recurrence. The therapy is a heat-based approach in which bladder tumour specific single-walled carbon nanotubes (SWCNTs) are delivered intravesically at a very low dose (0.1 mg SWCNT per kg body weight) followed 24 h later by a short 30 s treatment with a 360° near-infrared light that heats only the bound nanotubes. The energy density of the treatment was 50 J cm-2, and the power density that this treatment corresponds to is 1.7 W cm-2, which is relatively low. Nanotubes are specifically targeted to the tumour via the interaction of annexin V (AV) and phosphatidylserine, which is normally internalised on healthy tissue but externalised on tumours and the tumour vasculature. SWCNTs are conjugated to AV, which binds specifically to bladder cancer cells as confirmed in vitro and in vivo. Due to this specific localisation, NIR light can be used to heat the tumour while conserving the healthy bladder wall. In a short-term efficacy study in mice with orthotopic MB49 murine bladder tumours treated with the SWCNT-AV conjugate and NIR light, no tumours were visible on the bladder wall 24 h after NIR light treatment, and there was no damage to the bladder. In a separate survival study in mice with the same type of orthotopic tumours, there was a 50% cure rate at 116 days when the study was ended. At 116 days, no treatment toxicity was observed, and no nanotubes were detected in the clearance organs or bladder.
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Affiliation(s)
- Needa A Virani
- School of Biomedical Engineering, University of Oklahoma, 202 W. Boyd Street, Norman, OK 73019, United States of America
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29
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Desai TJ, Toombs JE, Minna JD, Brekken RA, Udugamasooriya DG. Identification of lipid-phosphatidylserine (PS) as the target of unbiasedly selected cancer specific peptide-peptoid hybrid PPS1. Oncotarget 2017; 7:30678-90. [PMID: 27120792 PMCID: PMC5058709 DOI: 10.18632/oncotarget.8929] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 03/31/2016] [Indexed: 12/20/2022] Open
Abstract
Phosphatidylserine (PS) is an anionic phospholipid maintained on the inner-leaflet of the cell membrane and is externalized in malignant cells. We previously launched a careful unbiased selection targeting biomolecules (e.g. protein, lipid or carbohydrate) distinct to cancer cells by exploiting HCC4017 lung cancer and HBEC30KT normal epithelial cells derived from the same patient, identifying HCC4017 specific peptide-peptoid hybrid PPS1. In this current study, we identified PS as the target of PPS1. We validated direct PPS1 binding to PS using ELISA-like assays, lipid dot blot and liposome based binding assays. In addition, PPS1 recognized other negatively charged and cancer specific lipids such as phosphatidic acid, phosphatidylinositol and phosphatidylglycerol. PPS1 did not bind to neutral lipids such as phosphatidylethanolamine found in cancer and phosphatidylcholine and sphingomyelin found in normal cells. Further we found that the dimeric version of PPS1 (PPS1D1) displayed strong cytotoxicity towards lung cancer cell lines that externalize PS, but not normal cells. PPS1D1 showed potent single agent anti-tumor activity and enhanced the efficacy of docetaxel in mice bearing H460 lung cancer xenografts. Since PS and anionic phospholipid externalization is common across many cancer types, PPS1 may be an alternative to overcome limitations of protein targeted agents.
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Affiliation(s)
- Tanvi J Desai
- Department of Pharmacological and Pharmaceutical Sciences, University of Houston, Houston, TX 77204, USA
| | - Jason E Toombs
- Hamon Center for Therapeutic Oncology Research, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - John D Minna
- Hamon Center for Therapeutic Oncology Research, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.,Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.,Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.,Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Rolf A Brekken
- Hamon Center for Therapeutic Oncology Research, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.,Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.,Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.,Department of Surgery, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Damith Gomika Udugamasooriya
- Department of Pharmacological and Pharmaceutical Sciences, University of Houston, Houston, TX 77204, USA.,Department of Cancer Systems Imaging, MD Anderson Cancer Center, Houston, TX 77030, USA
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30
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Lima L, Oliveira A, Campos L, Bonamino M, Chammas R, Werneck C, Vicente C, Barcinski M, Petersen L, Monteiro R. Malignant transformation in melanocytes is associated with increased production of procoagulant microvesicles. Thromb Haemost 2017; 106:712-23. [DOI: 10.1160/th11-03-0143] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Accepted: 06/30/2011] [Indexed: 01/08/2023]
Abstract
SummaryShedding of microvesicles (MVs) by cancer cells is implicated in a variety of biological effects, including the establishment of cancer-associated hypercoagulable states. However, the mechanisms underlying malignant transformation and the acquisition of procoagulant properties by tumour-derived MVs are poorly understood. Here we investigated the procoagulant and prothrombotic properties of MVs produced by a melanocyte-derived cell line (melan-a) as compared to its tumourigenic melanoma counterpart Tm1. Tumour cells exhibit a two-fold higher rate of MVs production as compared to melan-a. Melanoma MVs display greater procoagulant activity and elevated levels of the clotting initiator protein tissue factor (TF). On the other hand, tumour- and melanocyte- derived MVs expose similar levels of the procoagulant lipid phosphatidylserine, displaying identical abilities to support thrombin generation by the prothrombinase complex. By using an arterial thrombosis model, we observed that melanoma- but not melanocyte-derived MVs strongly accelerate thrombus formation in a TF-dependent manner, and accumulate at the site of vascular injury. Analysis of plasma obtained from melanoma-bearing mice showed the presence of MVs with a similar procoagulant pattern as compared to Tm1 MVs produced in vitro. Remarkably, flow-cytometric analysis demonstrated that 60% of ex vivo MVs are TF-positive and carry the melanoma-associated antigen, demonstrating its tumour origin. Altogether our data suggest that malignant transformation in melanocytes increases the production of procoagulant MVs, which may contribute for a variety of coagulation- related protumoural responses.
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31
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Shukla SP, Udugamasooriya DG. A mini-library system to investigate non-essential residues of lipid-phosphatidylserine (PS) binding peptide-peptoid hybrid PPS1. MEDCHEMCOMM 2017. [PMID: 29527284 DOI: 10.1039/c7md00372b] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We recently identified a peptide-peptoid hybrid, PPS1, which specifically recognized lipid-phosphatidylserine (PS). PPS1 consists of distinct positively charged and hydrophobic residue-containing regions. PPS1 monomer was inactive, but the dimeric form, PPS1D1, displayed strong cytotoxicity for lung cancer cells compared to normal cells in vitro, and reduced the tumor growth in vivo. The minimum pharmacophore of PPS1D1 showed that the first (methionine) and fourth (N-lysine) residues were not important for PPS1D1 cytotoxic activity. In this study, we further investigated these two residues, in particular the fourth residue that lies between the most important four residue hydrophobic region and two positively charged residues, to determine whether replacements of these moieties could gain activity improvements, or render PPS1D1 totally insensitive for binding recognition. The positively charged fourth residue N-lysine was replaced with the substituents having varied physiochemical properties, such as aromatic-hydrophobic, aliphatic-alicyclic, heterocyclic, and negatively charged residues, developing a mini-library of 39 derivatives. The standard 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) colorimetric and/or the calcein AM cell viability assays performed on HCC4017 lung cancer cells indicated that the fourth position of PPS1D1 was insensitive to most changes, except reversal to the negative charge significantly affected the activity. This observation may be due to the neutralization of the nearby positively charged residue that is essential for binding. In addition, shortening each monomeric sequence by eliminating the methionine at the first position did not affect the activity.
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Affiliation(s)
- Satya Prakash Shukla
- Department of Pharmacological & Pharmaceutical Sciences, University of Houston, 3455 Cullen Blvd., Houston, TX 77204-5037, USA
| | - D Gomika Udugamasooriya
- Department of Pharmacological & Pharmaceutical Sciences, University of Houston, 3455 Cullen Blvd., Houston, TX 77204-5037, USA.,Department of Cancer Systems Imaging, MD Anderson Cancer Center, 1881 East Road, Houston, TX 77030-4009, USA
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32
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Akalu YT, Rothlin CV, Ghosh S. TAM receptor tyrosine kinases as emerging targets of innate immune checkpoint blockade for cancer therapy. Immunol Rev 2017; 276:165-177. [PMID: 28258690 DOI: 10.1111/imr.12522] [Citation(s) in RCA: 119] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Cancer immunotherapy utilizing T-cell checkpoint inhibitors has shown tremendous clinical success. Yet, this mode of treatment is effective in only a subset of patients. Unresponsive patients tend to have non-T-cell-inflamed tumors that lack markers associated with the activation of adaptive anti-tumor immune responses. Notably, elimination of cancer cells by T cells is critically dependent on the optimal activity of innate immune cells. Therefore, identifying new targets that regulate innate immune cell function and promote the engagement of adaptive tumoricidal responses is likely to lead to the development of improved therapies against cancer. Here, we review the TAM receptor tyrosine kinases-TYRO3, AXL, and MERTK-as an emerging class of innate immune checkpoints that participate in key steps of anti-tumoral immunity. Namely, TAM-mediated efferocytosis, negative regulation of dendritic cell activity, and dysregulated production of chemokines collectively favor the escape of malignant cells. Hence, disabling TAM signaling may promote engagement of adaptive immunity and complement T-cell checkpoint blockade.
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Affiliation(s)
- Yemsratch T Akalu
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT, USA
| | - Carla V Rothlin
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT, USA.,Department of Pharmacology, Yale University School of Medicine, New Haven, CT, USA
| | - Sourav Ghosh
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT, USA.,Department of Neurology, Yale University School of Medicine, New Haven, CT, USA
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33
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Liu YW, Shia KS, Wu CH, Liu KL, Yeh YC, Lo CF, Chen CT, Chen YY, Yeh TK, Chen WH, Jan JJ, Huang YC, Huang CL, Fang MY, Gray BD, Pak KY, Hsu TA, Huang KH, Tsou LK. Targeting Tumor Associated Phosphatidylserine with New Zinc Dipicolylamine-Based Drug Conjugates. Bioconjug Chem 2017; 28:1878-1892. [PMID: 28581724 DOI: 10.1021/acs.bioconjchem.7b00225] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
A series of zinc(II) dipicolylamine (ZnDPA)-based drug conjugates have been synthesized to probe the potential of phosphatidylserine (PS) as a new antigen for small molecule drug conjugate (SMDC) development. Using in vitro cytotoxicity and plasma stability studies, PS-binding assay, in vivo pharmacokinetic studies, and maximum tolerated dose profiles, we provided a roadmap and the key parameters required for the development of the ZnDPA based drug conjugate. In particular, conjugate 24 induced tumor regression in the COLO 205 xenograft model and exhibited a more potent antitumor effect with a 70% reduction of cytotoxic payload compared to that of the marketed irinotecan when dosed at the same regimen. In addition to the validation of PS as an effective pharmacodelivery target for SMDC, our work also provided the foundation that, if applicable, a variety of therapeutic agents could be conjugated in the same manner to treat other PS-associated diseases.
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Affiliation(s)
- Yu-Wei Liu
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes , Miaoli 35053, Taiwan, ROC
| | - Kak-Shan Shia
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes , Miaoli 35053, Taiwan, ROC
| | - Chien-Huang Wu
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes , Miaoli 35053, Taiwan, ROC
| | - Kuan-Liang Liu
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes , Miaoli 35053, Taiwan, ROC
| | - Yu-Cheng Yeh
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes , Miaoli 35053, Taiwan, ROC
| | - Chen-Fu Lo
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes , Miaoli 35053, Taiwan, ROC
| | - Chiung-Tong Chen
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes , Miaoli 35053, Taiwan, ROC
| | - Yun-Yu Chen
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes , Miaoli 35053, Taiwan, ROC
| | - Teng-Kuang Yeh
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes , Miaoli 35053, Taiwan, ROC
| | - Wei-Han Chen
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes , Miaoli 35053, Taiwan, ROC
| | - Jiing-Jyh Jan
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes , Miaoli 35053, Taiwan, ROC
| | - Yu-Chen Huang
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes , Miaoli 35053, Taiwan, ROC
| | - Chen-Lung Huang
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes , Miaoli 35053, Taiwan, ROC
| | - Ming-Yu Fang
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes , Miaoli 35053, Taiwan, ROC
| | - Brian D Gray
- Molecular Targeting Technologies, Inc. , West Chester, Pennsylvania 19380, United States
| | - Koon Y Pak
- Molecular Targeting Technologies, Inc. , West Chester, Pennsylvania 19380, United States
| | - Tsu-An Hsu
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes , Miaoli 35053, Taiwan, ROC
| | - Kuan-Hsun Huang
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes , Miaoli 35053, Taiwan, ROC
| | - Lun K Tsou
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes , Miaoli 35053, Taiwan, ROC
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34
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Shukla SP, Manarang JC, Udugamasooriya DG. A unique mid-sequence linker used to multimerize the lipid-phosphatidylserine (PS) binding peptide-peptoid hybrid PPS1. Eur J Med Chem 2017; 137:1-10. [PMID: 28551176 DOI: 10.1016/j.ejmech.2017.05.040] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Revised: 04/26/2017] [Accepted: 05/17/2017] [Indexed: 02/07/2023]
Abstract
Ligand multimerizations enhance the binding affinity towards cell surface biomarkers through their avidity effects. Typical linkers connect individual monomeric ligand moieties from one end (e.g., C- or N-terminus of a peptide) and exclusively target protein receptors. The lipid phosphatidylserine (PS) is normally present on the cytoplasmic side of the eukaryotic cell membrane, but in tumors and tumor endothelial cells, this negatively charged PS flips to the outer layer. We recently reported a PS binding peptide-peptoid hybrid (PPS1) that has distinct positively charged and hydrophobic residue-containing regions. The PPS1 monomer is inactive, and upon C-terminal dimerization (PPS1D1), it triggers cytotoxicity. In the current study, a unique series of PPS1 multimeric derivatives were synthesized by switching the linker from the C-terminus to an internal position. The unimportant fourth residue (N-lys) from the C-terminus was utilized to build the linker. The synthesis strategy was developed employing variations of (I) the linker size, (II) the number of positively charged residues, and (III) the number of hydrophobic regions. Cytotoxicity of these new derivatives on HCC4017 lung cancer cells showed that a minimum of two hydrophobic regions was important to retain the activity and that the shortest linker length was optimal for activity.
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Affiliation(s)
- Satya Prakash Shukla
- Department of Pharmacological & Pharmaceutical Sciences, University of Houston, 3455 Cullen Blvd., Houston, TX 77204-5037, USA
| | - Joseph C Manarang
- Department of Pharmacological & Pharmaceutical Sciences, University of Houston, 3455 Cullen Blvd., Houston, TX 77204-5037, USA
| | - D Gomika Udugamasooriya
- Department of Pharmacological & Pharmaceutical Sciences, University of Houston, 3455 Cullen Blvd., Houston, TX 77204-5037, USA; Department of Cancer Systems Imaging, MD Anderson Cancer Center, 1881 East Road, Houston, TX 77030-4009, USA.
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35
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Krais JJ, Virani N, McKernan PH, Nguyen Q, Fung KM, Sikavitsas VI, Kurkjian C, Harrison RG. Antitumor Synergism and Enhanced Survival with a Tumor Vasculature-Targeted Enzyme Prodrug System, Rapamycin, and Cyclophosphamide. Mol Cancer Ther 2017; 16:1855-1865. [PMID: 28522586 DOI: 10.1158/1535-7163.mct-16-0263] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Revised: 01/17/2017] [Accepted: 05/09/2017] [Indexed: 11/16/2022]
Abstract
Mutant cystathionine gamma-lyase was targeted to phosphatidylserine exposed on tumor vasculature through fusion with Annexin A1 or Annexin A5. Cystathionine gamma-lyase E58N, R118L, and E338N mutations impart nonnative methionine gamma-lyase activity, resulting in tumor-localized generation of highly toxic methylselenol upon systemic administration of nontoxic selenomethionine. The described therapeutic system circumvents systemic toxicity issues using a novel drug delivery/generation approach and avoids the administration of nonnative proteins and/or DNA required with other enzyme prodrug systems. The enzyme fusion exhibits strong and stable in vitro binding with dissociation constants in the nanomolar range for both human and mouse breast cancer cells and in a cell model of tumor vascular endothelium. Daily administration of the therapy suppressed growth of highly aggressive triple-negative murine 4T1 mammary tumors in immunocompetent BALB/cJ mice and MDA-MB-231 tumors in SCID mice. Treatment did not result in the occurrence of negative side effects or the elicitation of neutralizing antibodies. On the basis of the vasculature-targeted nature of the therapy, combinations with rapamycin and cyclophosphamide were evaluated. Rapamycin, an mTOR inhibitor, reduces the prosurvival signaling of cells in a hypoxic environment potentially exacerbated by a vasculature-targeted therapy. IHC revealed, unsurprisingly, a significant hypoxic response (increase in hypoxia-inducible factor 1 α subunit, HIF1A) in the enzyme prodrug-treated tumors and a dramatic reduction of HIF1A upon rapamycin treatment. Cyclophosphamide, an immunomodulator at low doses, was combined with the enzyme prodrug therapy and rapamycin; this combination synergistically reduced tumor volumes, inhibited metastatic progression, and enhanced survival. Mol Cancer Ther; 16(9); 1855-65. ©2017 AACR.
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Affiliation(s)
- John J Krais
- School of Biomedical Engineering, University of Oklahoma, Norman, Oklahoma
| | - Needa Virani
- School of Biomedical Engineering, University of Oklahoma, Norman, Oklahoma
| | - Patrick H McKernan
- School of Biomedical Engineering, University of Oklahoma, Norman, Oklahoma
| | - Quang Nguyen
- School of Chemical, Biological and Materials Engineering, University of Oklahoma, Norman, Oklahoma
| | - Kar-Ming Fung
- Department of Pathology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Vassilios I Sikavitsas
- School of Chemical, Biological and Materials Engineering, University of Oklahoma, Norman, Oklahoma
| | - Carla Kurkjian
- Oncology/Hematology Section, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Roger G Harrison
- School of Biomedical Engineering, University of Oklahoma, Norman, Oklahoma. .,School of Chemical, Biological and Materials Engineering, University of Oklahoma, Norman, Oklahoma
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36
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Bacteriophages and Their Immunological Applications against Infectious Threats. J Immunol Res 2017; 2017:3780697. [PMID: 28484722 PMCID: PMC5412166 DOI: 10.1155/2017/3780697] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 03/19/2017] [Indexed: 01/06/2023] Open
Abstract
Bacteriophage therapy dates back almost a century, but the discovery of antibiotics led to a rapid decline in the interests and investments within this field of research. Recently, the novel threat of multidrug-resistant bacteria highlighted the alarming drop in research and development of new antibiotics: 16 molecules were discovered during 1983–87, 10 new therapeutics during the nineties, and only 5 between 2003 and 2007. Phages are therefore being reconsidered as alternative therapeutics. Phage display technique has proved to be extremely promising for the identification of effective antibodies directed against pathogens, as well as for vaccine development. At the same time, conventional phage therapy uses lytic bacteriophages for treatment of infections and recent clinical trials have shown great potential. Moreover, several other approaches have been developed in vitro and in vivo using phage-derived proteins as antibacterial agents. Finally, their use has also been widely considered for public health surveillance, as biosensor phages can be used to detect food and water contaminations and prevent bacterial epidemics. These novel approaches strongly promote the idea that phages and their proteins can be exploited as an effective weapon in the near future, especially in a world which is on the brink of a “postantibiotic era.”
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37
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Phosphatidylserine Outer Layer Translocation Is Implicated in IL-10 Secretion by Human Regulatory B Cells. PLoS One 2017; 12:e0169755. [PMID: 28072868 PMCID: PMC5225009 DOI: 10.1371/journal.pone.0169755] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 12/21/2016] [Indexed: 12/22/2022] Open
Abstract
B cells can have a regulatory role, mainly mediated by interleukin 10 (IL-10). IL-10 producing B cells (B10 cells) cells remain to be better characterized. Annexin V binds phosphatidylserine (PS), which is externalized during apoptosis. Previous works suggested that B10 cells are apoptotic cells since they bind Annexin V. Others showed that Annexin V binding could also be expressed on viable B cells. We aimed to explore if PS exposure can be a marker of B10 cells and if PS exposure has a functional role on B cell IL-10 production in healthy subjects. We found that B10 cells were significantly more often Annexin V+ than IL-10 non-producing B cells. After CpG activation, Annexin V+ B cells differentiated more often into B10 cells than Annexin Vneg B cells. Cell death and early apoptosis were similar between Annexin V+ and Annexin Vneg B cells. PS blockage, using biotinylated AnV and glyburide, decreased B10 cell differentiation. This study showed that B10 cells have an increased PS exposure independently of any apoptotic state. B cells exposing PS differentiate more into B10 cells whereas PS blockage inhibits B10 cells generation. These results strongly suggest a link between PS exposure and B10 cells.
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38
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Gebremeskel S, Johnston B. Concepts and mechanisms underlying chemotherapy induced immunogenic cell death: impact on clinical studies and considerations for combined therapies. Oncotarget 2016; 6:41600-19. [PMID: 26486085 PMCID: PMC4747176 DOI: 10.18632/oncotarget.6113] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 09/22/2015] [Indexed: 01/12/2023] Open
Abstract
Chemotherapy has historically been thought to induce cancer cell death in an immunogenically silent manner. However, recent studies have demonstrated that therapeutic outcomes with specific chemotherapeutic agents (e.g. anthracyclines) correlate strongly with their ability to induce a process of immunogenic cell death (ICD) in cancer cells. This process generates a series of signals that stimulate the immune system to recognize and clear tumor cells. Extensive studies have revealed that chemotherapy-induced ICD occurs via the exposure/release of calreticulin (CALR), ATP, chemokine (C–X–C motif) ligand 10 (CXCL10) and high mobility group box 1 (HMGB1). This review provides an in-depth look into the concepts and mechanisms underlying CALR exposure, activation of the Toll-like receptor 3/IFN/CXCL10 axis, and the release of ATP and HMGB1 from dying cancer cells. Factors that influence the impact of ICD in clinical studies and the design of therapies combining chemotherapy with immunotherapy are also discussed.
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Affiliation(s)
- Simon Gebremeskel
- Department of Microbiology & Immunology, Dalhousie University, Halifax, Nova Scotia, Canada.,Beatrice Hunter Cancer Research Institute, Halifax, Nova Scotia, Canada
| | - Brent Johnston
- Department of Microbiology & Immunology, Dalhousie University, Halifax, Nova Scotia, Canada.,Department of Pediatrics, Dalhousie University, Halifax, Nova Scotia, Canada.,Department of Pathology, Dalhousie University, Halifax, Nova Scotia, Canada.,Beatrice Hunter Cancer Research Institute, Halifax, Nova Scotia, Canada
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39
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Mineo C, Lanier L, Jung E, Sengupta S, Ulrich V, Sacharidou A, Tarango C, Osunbunmi O, Shen YM, Salmon JE, Brekken RA, Huang X, Thorpe PE, Shaul PW. Identification of a Monoclonal Antibody That Attenuates Antiphospholipid Syndrome-Related Pregnancy Complications and Thrombosis. PLoS One 2016; 11:e0158757. [PMID: 27463336 PMCID: PMC4963039 DOI: 10.1371/journal.pone.0158757] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 06/21/2016] [Indexed: 11/18/2022] Open
Abstract
In the antiphospholipid syndrome (APS), patients produce antiphospholipid antibodies (aPL) that promote thrombosis and adverse pregnancy outcomes. Current therapy with anticoagulation is only partially effective and associated with multiple complications. We previously discovered that aPL recognition of cell surface β2-glycoprotein I (β2-GPI) initiates apolipoprotein E receptor 2 (apoER2)-dependent signaling in endothelial cells and in placental trophoblasts that ultimately promotes thrombosis and fetal loss, respectively. Here we sought to identify a monoclonal antibody (mAb) to β2-GPI that negates aPL-induced processes in cell culture and APS disease endpoints in mice. In a screen measuring endothelial NO synthase (eNOS) activity in cultured endothelial cells, we found that whereas aPL inhibit eNOS, the mAb 1N11 does not, and instead 1N11 prevents aPL action. Coimmunoprecipitation studies revealed that 1N11 decreases pathogenic antibody binding to β2-GPI, and it blocks aPL-induced complex formation between β2-GPI and apoER2. 1N11 also prevents aPL antagonism of endothelial cell migration, and in mice it reverses the impairment in reendothelialization caused by aPL, which underlies the non-thrombotic vascular occlusion provoked by disease-causing antibodies. In addition, aPL inhibition of trophoblast proliferation and migration is negated by 1N11, and the more than 6-fold increase in fetal resorption caused by aPL in pregnant mice is prevented by 1N11. Furthermore, the promotion of thrombosis by aPL is negated by 1N11. Thus, 1N11 has been identified as an mAb that attenuates APS-related pregnancy complications and thrombosis in mice. 1N11 may provide an efficacious, mechanism-based therapy to combat the often devastating conditions suffered by APS patients.
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Affiliation(s)
- Chieko Mineo
- Center for Pulmonary and Vascular Biology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
- * E-mail: (CM); (PWS)
| | - Lane Lanier
- Center for Pulmonary and Vascular Biology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Eunjeong Jung
- Center for Pulmonary and Vascular Biology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Samarpita Sengupta
- Center for Pulmonary and Vascular Biology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Victoria Ulrich
- Center for Pulmonary and Vascular Biology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Anastasia Sacharidou
- Center for Pulmonary and Vascular Biology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Cristina Tarango
- Center for Pulmonary and Vascular Biology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Olutoye Osunbunmi
- Center for Pulmonary and Vascular Biology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Yu-Min Shen
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Jane E. Salmon
- Department of Medicine, Hospital for Special Surgery, Weill Cornell Medical College, New York, New York, United States of America
| | - Rolf A. Brekken
- Department of Pharmacology and the Hamon Center for Therapeutic Oncology Research, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
- Department of Surgery, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Xianming Huang
- Department of Pharmacology and the Hamon Center for Therapeutic Oncology Research, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Philip E. Thorpe
- Department of Pharmacology and the Hamon Center for Therapeutic Oncology Research, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Philip W. Shaul
- Center for Pulmonary and Vascular Biology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
- * E-mail: (CM); (PWS)
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Identification of the minimum pharmacophore of lipid-phosphatidylserine (PS) binding peptide-peptoid hybrid PPS1D1. Bioorg Med Chem 2016; 24:4470-4477. [PMID: 27485601 DOI: 10.1016/j.bmc.2016.07.045] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 07/17/2016] [Accepted: 07/20/2016] [Indexed: 12/26/2022]
Abstract
We previously reported a unique peptide-peptoid hybrid, PPS1 that specifically recognizes lipid-phosphatidylserine (PS) and a few other negatively charged phospholipids, but not neutral phospholipids, on the cell membrane. The dimeric version of PPS1, i.e., PPS1D1 triggers strong cancer cell cytotoxicity and has been validated in lung cancer models both in vitro and in vivo. Given that PS and other negatively charged phospholipids are abundant in almost all tumor microenvironments, PPS1D1 is an attractive drug lead that can be developed into a globally applicable anti-cancer agent. Therefore, it is extremely important to identify the minimum pharmacophore of PPS1D1. In this study, we have synthesized alanine/sarcosine derivatives as well as truncated derivatives of PPS1D1. We performed ELISA-like competitive binding assay to evaluate the PS-recognition potential and standard MTS cell viability assay on HCC4017 lung cancer cells to validate the cell cytotoxicity effects of these derivatives. Our studies indicate that positively charged residues at the second and third positions, as well as four hydrophobic residues at the fifth through eighth positions, are imperative for the binding and activity of PPS1D1. Methionine at the first position was not essential, whereas the positively charged Nlys at the fourth position was minimally needed, as two derivatives that were synthesized replacing this residue were almost as active as PPS1D1.
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Freimark BD, Gong J, Ye D, Gray MJ, Nguyen V, Yin S, Hatch MMS, Hughes CCW, Schroit AJ, Hutchins JT, Brekken RA, Huang X. Antibody-Mediated Phosphatidylserine Blockade Enhances the Antitumor Responses to CTLA-4 and PD-1 Antibodies in Melanoma. Cancer Immunol Res 2016; 4:531-40. [PMID: 27045021 DOI: 10.1158/2326-6066.cir-15-0250] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 01/20/2016] [Indexed: 12/11/2022]
Abstract
In tumor-bearing animals, the membrane phospholipid phosphatidylserine (PS) suppresses immune responses, suggesting that PS signaling could counteract the antitumor effect of antibody-driven immune checkpoint blockade. Here, we show that treating melanoma-bearing mice with a PS-targeting antibody enhances the antitumor activity of downstream checkpoint inhibition. Combining PS-targeting antibodies with CTLA-4 or PD-1 blockade resulted in significantly greater inhibition of tumor growth than did single-agent therapy. Moreover, combination therapy enhanced CD4(+) and CD8(+) tumor-infiltrating lymphocyte numbers; elevated the fraction of cells expressing the proinflammatory cytokines IL2, IFNγ, and TNFα; and increased the ratio of CD8 T cells to myeloid-derived suppressor cells and regulatory T cells in tumors. Similar changes in immune cell profiles were observed in splenocytes. Taken together, these data show that antibody-mediated PS blockade enhances the antitumor efficacy of immune checkpoint inhibition. Cancer Immunol Res; 4(6); 531-40. ©2016 AACR.
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Affiliation(s)
- Bruce D Freimark
- Department of Preclinical Research, Peregrine Pharmaceuticals, Inc., Tustin, California
| | - Jian Gong
- Department of Preclinical Research, Peregrine Pharmaceuticals, Inc., Tustin, California
| | - Dan Ye
- Hamon Center for Therapeutic Oncology Research, Departments of Surgery and Pharmacology, UT Southwestern Medical Center, Dallas, Texas
| | - Michael J Gray
- Department of Preclinical Research, Peregrine Pharmaceuticals, Inc., Tustin, California
| | - Van Nguyen
- Department of Preclinical Research, Peregrine Pharmaceuticals, Inc., Tustin, California
| | - Shen Yin
- Department of Preclinical Research, Peregrine Pharmaceuticals, Inc., Tustin, California
| | - Michaela M S Hatch
- Department of Molecular Biology and Biochemistry, University of California, Irvine, California
| | - Christopher C W Hughes
- Department of Molecular Biology and Biochemistry, University of California, Irvine, California
| | - Alan J Schroit
- Simmons Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Jeff T Hutchins
- Department of Preclinical Research, Peregrine Pharmaceuticals, Inc., Tustin, California
| | - Rolf A Brekken
- Hamon Center for Therapeutic Oncology Research, Departments of Surgery and Pharmacology, UT Southwestern Medical Center, Dallas, Texas. Simmons Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Xianming Huang
- Hamon Center for Therapeutic Oncology Research, Departments of Surgery and Pharmacology, UT Southwestern Medical Center, Dallas, Texas.
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Li T, Aredo B, Zhang K, Zhong X, Pulido JS, Wang S, He YG, Huang X, Brekken RA, Ufret-Vincenty RL. Phosphatidylserine (PS) Is Exposed in Choroidal Neovascular Endothelium: PS-Targeting Antibodies Inhibit Choroidal Angiogenesis In Vivo and Ex Vivo. Invest Ophthalmol Vis Sci 2016; 56:7137-45. [PMID: 26529048 DOI: 10.1167/iovs.15-17302] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
PURPOSE Choroidal neovascularization (CNV) accounts for 90% of cases of severe vision loss in patients with advanced age-related macular degeneration. Identifying new therapeutic targets for CNV may lead to novel combination therapies to improve outcomes and reduce treatment burden. Our goal was to test whether phosphatidylserine (PS) becomes exposed in the outer membrane of choroidal neovascular endothelium, and whether this could provide a new therapeutic target for CNV. METHODS Choroidal neovascularization was induced in C57BL/6J mice using laser photocoagulation. Choroidal neovascularization lesions costained for exposed PS and for intercellular adhesion molecule 2 (or isolectin B4) were imaged in flat mounts and in cross sections. The laser CNV model and a choroidal sprouting assay were used to test the effect of PS-targeting antibodies on choroidal angiogenesis. Choroidal neovascularization lesion size was determined by intercellular adhesion molecule 2 (ICAM-2) staining of flat mounts. RESULTS We found that PS was exposed in CNV lesions and colocalized with vascular endothelial staining. Treatment with PS-targeting antibodies led to a 40% to 80% reduction in CNV lesion area when compared to treatment with a control antibody. The effect was the same as that seen using an equal dose of an anti-VEGF antibody. Results were confirmed using the choroid sprouting assay, an ex vivo model of choroidal angiogenesis. CONCLUSIONS We demonstrated that PS is exposed in choroidal neovascular endothelium. Furthermore, targeting this exposed PS with antibodies may be of therapeutic value in CNV.
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Affiliation(s)
- Tao Li
- Department of Ophthalmology University of Texas Southwestern Medical Center, Dallas, Texas, United States 2Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People's Republic of Chi
| | - Bogale Aredo
- Department of Ophthalmology University of Texas Southwestern Medical Center, Dallas, Texas, United States
| | - Kaiyan Zhang
- Department of Ophthalmology University of Texas Southwestern Medical Center, Dallas, Texas, United States 3Department of Ophthalmology, Hainan Provincial People's Hospital, Haikou, Hainan, People's Republic of China
| | - Xin Zhong
- Department of Ophthalmology University of Texas Southwestern Medical Center, Dallas, Texas, United States
| | - Jose S Pulido
- Departments of Ophthalmology and Molecular Medicine, Mayo Clinic, Rochester, Minnesota, United States
| | - Shusheng Wang
- Departments of Cell and Molecular Biology and Ophthalmology, Tulane University, New Orleans, Louisiana, United States
| | - Yu-Guang He
- Department of Ophthalmology University of Texas Southwestern Medical Center, Dallas, Texas, United States
| | - Xianming Huang
- Department of Pharmacology and the Hamon Center for Therapeutic Oncology Research, University of Texas Southwestern Medical Center, Dallas, Texas, United States
| | - Rolf A Brekken
- Department of Pharmacology and the Hamon Center for Therapeutic Oncology Research, University of Texas Southwestern Medical Center, Dallas, Texas, United States 7Department of Surgery, University of Texas Southwestern Medical Center, Dallas, Texas, United
| | - Rafael L Ufret-Vincenty
- Department of Ophthalmology University of Texas Southwestern Medical Center, Dallas, Texas, United States
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Docetaxel Combined With Bavituximab in Previously Treated, Advanced Nonsquamous Non-Small-Cell Lung Cancer. Clin Lung Cancer 2016; 17:169-76. [PMID: 27265742 DOI: 10.1016/j.cllc.2016.02.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Revised: 02/05/2016] [Accepted: 02/09/2016] [Indexed: 12/21/2022]
Abstract
BACKGROUND Bavituximab is a phosphatidylserine-targeting antibody with a selective tumor, vascular-directed immune response. In this phase II trial the efficacy and safety of bavituximab combined with docetaxel for previously treated, advanced nonsquamous non-small-cell lung cancer were evaluated. PATIENTS AND METHODS Patients were randomized 1:1:1 to receive docetaxel 75 mg/m(2) every 21 days for up to 6 cycles combined with weekly, blinded infusions of placebo, bavituximab 1 mg/kg, or bavituximab 3 mg/kg until disease progression or unacceptable toxicity. The primary end point was overall response rate (ORR), with a predefined end point of 26% in the bavituximab arms. After study unblinding, vial-coding discrepancies were discovered in the placebo and bavituximab 1 mg/kg groups. In exploratory analyses, data from these groups were pooled to form the control group and compared with the 3 mg/kg group. RESULTS Efficacy end points in the bavituximab 3 mg/kg group (n = 41) and in the placebo/bavituximab 1 mg/kg group (n = 80), respectively, were as follows: ORR, 17.1% (95% confidence interval [CI], 5.6%-28.6%) and ORR, 11.3% (95% CI, 4.3%-18.2%); median progression-free survival 4.5 and 3.3 months (hazard ratio [HR], 0.74 [95% CI, 0.45-1.21]; P = .24); median overall survival 11.7 and 7.3 months (HR, 0.66 [95% CI, 0.40-1.10]; P = .11). Toxicities were manageable and similar between arms. CONCLUSION The combination of bavituximab and docetaxel is well tolerated. Although no firm efficacy conclusions can be drawn and the trial did not meet the predefined primary end point, exploratory analyses suggest trends favoring the combination of bavituximab 3 mg/kg with docetaxel. This regimen is being evaluated in the ongoing, global, phase III SUNRISE trial.
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Cheng X, Li L, Thorpe PE, Yopp AC, Brekken RA, Huang X. Antibody-Mediated Blockade of Phosphatidylserine Enhances the Antitumor Effect of Sorafenib in Hepatocellular Carcinomas Xenografts. Ann Surg Oncol 2016; 23:583-591. [PMID: 26847681 DOI: 10.1245/s10434-016-5107-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Indexed: 12/21/2022]
Abstract
BACKGROUND Currently, the only FDA-approved systemic therapy for hepatocellular carcinoma (HCC) is the multi-receptor tyrosine kinase inhibitor, sorafenib, which provides only modest clinical benefit. We recently showed that treatment with a phosphatidylserine (PS) targeting agent suppresses tumor growth by targeting tumor vasculature and reactivating antitumor immunity. METHODS We tested the hypothesis that sorafenib increases PS exposure on tumor vasculature, thereby enhancing the antitumor efficacy of PS targeting. We evaluated the efficacy of combining a PS targeting agent (2aG4) with sorafenib in murine xenograft models of human HCC. RESULTS Our results demonstrate that combination of 2aG4 and sorafenib had a superior therapeutic effect over single agent therapy. Mechanistic studies showed that sorafenib significantly increased PS exposure on tumor vasculature; the percentage of PS-positive vessels increased from 19 to 52, 23 to 68, and 30 to 55 % in PLC/PRF/5, C3A, and Huh7 tumors, respectively. Combination therapy significantly decreased tumor microvessel density and the level of M2 macrophages, while increasing the apoptotic index of tumor endothelial cells and the frequency of M1 macrophages. Furthermore, we report the findings of a Phase I clinical study of bavituximab, a chimeric version of 2aG4, combined with sorafenib in HCC patients. The Phase I results demonstrate the appropriate dose of bavituximab to be given with sorafenib in future clinical trials. CONCLUSIONS Overall, these results strongly support the combination of bavituximab with sorafenib as a promising systemic therapeutic strategy for the treatment for advanced HCC patients.
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Affiliation(s)
- Xiaoyun Cheng
- Hamon Center for Therapeutic Oncology Research, UT Southwestern Medical Center, Dallas, TX, USA
| | - Li Li
- Hamon Center for Therapeutic Oncology Research, UT Southwestern Medical Center, Dallas, TX, USA
| | - Philip E Thorpe
- Hamon Center for Therapeutic Oncology Research, UT Southwestern Medical Center, Dallas, TX, USA.,Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Adam C Yopp
- Division of Surgical Oncology, Department of Surgery, UT Southwestern Medical Center, Dallas, TX, USA
| | - Rolf A Brekken
- Hamon Center for Therapeutic Oncology Research, UT Southwestern Medical Center, Dallas, TX, USA. .,Division of Surgical Oncology, Department of Surgery, UT Southwestern Medical Center, Dallas, TX, USA. .,Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX, USA.
| | - Xianming Huang
- Hamon Center for Therapeutic Oncology Research, UT Southwestern Medical Center, Dallas, TX, USA. .,Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX, USA.
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Matharage JM, Minna JD, Brekken RA, Udugamasooriya DG. Unbiased Selection of Peptide-Peptoid Hybrids Specific for Lung Cancer Compared to Normal Lung Epithelial Cells. ACS Chem Biol 2015; 10:2891-9. [PMID: 26509598 DOI: 10.1021/acschembio.5b00592] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
To develop widely applicable diagnostic and potentially therapeutic approaches overcoming protein heterogeneity in human cancer, we have developed a technology to unbiasedly select high specificity compound(s) that bind any biomolecule (e.g., proteins, lipids, carbohydrates) presented on the cancer cell surface but not on normal cells. We utilized a peptidomimetic based on-bead two-color (OBTC) combinatorial cell screen that can detect differences between two cell surfaces at high accuracy by looking for beads (where each bead in the library had one peptide-peptoid hybrid on the surface) that only bound cancer but not normal cells. We screened a library of 393 216 compounds targeting HCC4017 lung adenocarcinoma cells (labeled in red) in the presence of HBEC30KT normal bronchial epithelial cells (labeled in green) derived from the same tissue of the same patient. This screen identified a peptide-peptoid hybrid called PPS1 which displayed high specific binding for HCC4017 cancer cells over HBEC30KT cells. Specificity was validated through on-bead, ELISA-like and magnetic bead pulldown studies, while a scrambled version of PPS1 did not show any binding. Of interest, the simple dimeric version (PPS1D1) displayed cytotoxic activity on HCC4017 cells, but not on normal HBEC30KT cells. PPS1D1 also strongly accumulated in HCC4017 lung cancer xenografts in mice over control constructs. We conclude that such combinatorial screens using tumor and normal cells from the same patient have significant potential to develop new reagents for cancer biology, diagnosis, and potentially therapy.
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Affiliation(s)
- Jaya M. Matharage
- Advanced Imaging Research Center, ‡Simmons Comprehensive
Cancer Center, §Hamon Center for Therapeutic
Oncology Research, ∥Departments of Biochemistry, ⊥Pharmacology, #Internal Medicine, and ▽Surgery, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, Texas 75390, United States
| | - John D. Minna
- Advanced Imaging Research Center, ‡Simmons Comprehensive
Cancer Center, §Hamon Center for Therapeutic
Oncology Research, ∥Departments of Biochemistry, ⊥Pharmacology, #Internal Medicine, and ▽Surgery, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, Texas 75390, United States
| | - Rolf A. Brekken
- Advanced Imaging Research Center, ‡Simmons Comprehensive
Cancer Center, §Hamon Center for Therapeutic
Oncology Research, ∥Departments of Biochemistry, ⊥Pharmacology, #Internal Medicine, and ▽Surgery, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, Texas 75390, United States
| | - D. Gomika Udugamasooriya
- Advanced Imaging Research Center, ‡Simmons Comprehensive
Cancer Center, §Hamon Center for Therapeutic
Oncology Research, ∥Departments of Biochemistry, ⊥Pharmacology, #Internal Medicine, and ▽Surgery, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, Texas 75390, United States
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The phospholipid code: a key component of dying cell recognition, tumor progression and host-microbe interactions. Cell Death Differ 2015; 22:1893-905. [PMID: 26450453 DOI: 10.1038/cdd.2015.122] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Revised: 08/05/2015] [Accepted: 08/06/2015] [Indexed: 02/06/2023] Open
Abstract
A significant effort is made by the cell to maintain certain phospholipids at specific sites. It is well described that proteins involved in intracellular signaling can be targeted to the plasma membrane and organelles through phospholipid-binding domains. Thus, the accumulation of a specific combination of phospholipids, denoted here as the 'phospholipid code', is key in initiating cellular processes. Interestingly, a variety of extracellular proteins and pathogen-derived proteins can also recognize or modify phospholipids to facilitate the recognition of dying cells, tumorigenesis and host-microbe interactions. In this article, we discuss the importance of the phospholipid code in a range of physiological and pathological processes.
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de Melo ET, Estrela AB, Santos ECG, Machado PRL, Farias KJS, Torres TM, Carvalho E, Lima JPMS, Silva-Júnior AA, Barbosa EG, Fernandes-Pedrosa MDF. Structural characterization of a novel peptide with antimicrobial activity from the venom gland of the scorpion Tityus stigmurus: Stigmurin. Peptides 2015; 68:3-10. [PMID: 25805002 DOI: 10.1016/j.peptides.2015.03.003] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Revised: 03/02/2015] [Accepted: 03/05/2015] [Indexed: 01/05/2023]
Abstract
A new antimicrobial peptide, herein named Stigmurin, was selected based on a transcriptomic analysis of the Brazilian yellow scorpion Tityus stigmurus venom gland, an underexplored source for toxic peptides with possible biotechnological applications. Stigmurin was investigated in silico, by circular dichroism (CD) spectroscopy, and in vitro. The CD spectra suggested that this peptide interacts with membranes, changing its conformation in the presence of an amphipathic environment, with predominance of random coil and beta-sheet structures. Stigmurin exhibited antibacterial and antifungal activity, with minimal inhibitory concentrations ranging from 8.7 to 69.5μM. It was also showed that Stigmurin is toxic against SiHa and Vero E6 cell lines. The results suggest that Stigmurin can be considered a potential anti-infective drug.
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Affiliation(s)
- Edinara Targino de Melo
- Laboratório de Tecnologia e Biotecnologia Farmacêutica, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil
| | - Andréia Bergamo Estrela
- Laboratório de Tecnologia e Biotecnologia Farmacêutica, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil
| | | | | | | | - Taffarel Melo Torres
- Departamento de Ciências Animais, Universidade Federal Rural do Semi-Árido, Mossoró, RN, Brazil
| | - Enéas Carvalho
- Centro de Biotecnologia, Instituto Butantan, São Paulo, SP, Brazil
| | | | - Arnóbio Antonio Silva-Júnior
- Laboratório de Tecnologia e Biotecnologia Farmacêutica, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil
| | | | - Matheus de Freitas Fernandes-Pedrosa
- Laboratório de Tecnologia e Biotecnologia Farmacêutica, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil; Programa de Pós-Graduação em Bioquímica, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil.
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Adams B, Herold M, Ferstl E, Choi J, Zhu S. Anticancer effects of monocarbonyl analogs of curcumin: oxidative stress, nuclear translocation and modulation of AP-1 and NF-κB. INTERNATIONAL JOURNAL OF CANCER THERAPY AND ONCOLOGY 2015. [DOI: 10.14319/ijcto.32.19] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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Bujak E, Pretto F, Neri D. Generation and tumor recognition properties of two human monoclonal antibodies specific to cell surface anionic phospholipids. Invest New Drugs 2015; 33:791-800. [PMID: 25983040 DOI: 10.1007/s10637-015-0248-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Accepted: 04/29/2015] [Indexed: 11/28/2022]
Abstract
Phosphatidylserine (PS) and other anionic phospholipids, which become exposed on the surface of proliferating endothelial cells, tumor cells and certain leukocytes, have been used as targets for the development of clinical-stage biopharmaceuticals. One of these products (bavituximab) is currently being investigated in Phase 3 clinical trials. There are conflicting reports on the ability of bavituximab and other antibodies to recognize PS directly or through beta-2 glycoprotein 1, a serum protein that is not highly conserved across species. Here, we report on the generation and characterization of two fully human antibodies directed against phosphatidylserine. One of these antibodies (PS72) bound specifically to phosphatidylserine and to phosphatidic acid, but did not recognize other closely related phospholipids, while the other antibody (PS41) also bound to cardiolipin. Both PS72 and PS41 stained 8/9 experimental tumor models in vitro, but both antibodies failed to exhibit a preferential tumor accumulation in vivo, as revealed by quantitative biodistribution analysis. Our findings indicate that anionic phospholipids are exposed and accessible in most tumor types, but cast doubts about the possibility of efficiently targeting tumors in vivo with PS-specific reagents.
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Affiliation(s)
- Emil Bujak
- Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093, Zurich, Switzerland
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Effective binding of a phosphatidylserine-targeting antibody to Ebola virus infected cells and purified virions. J Immunol Res 2015; 2015:347903. [PMID: 25815346 PMCID: PMC4359806 DOI: 10.1155/2015/347903] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Revised: 06/20/2014] [Accepted: 09/03/2014] [Indexed: 11/17/2022] Open
Abstract
Ebola virus is responsible for causing severe hemorrhagic fevers, with case fatality rates of up to 90%. Currently, no antiviral or vaccine is licensed against Ebola virus. A phosphatidylserine-targeting antibody (PGN401, bavituximab) has previously been shown to have broad-spectrum antiviral activity. Here, we demonstrate that PGN401 specifically binds to Ebola virus and recognizes infected cells. Our study provides the first evidence of phosphatidylserine-targeting antibody reactivity against Ebola virus.
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