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Moody TW, Lee L, Ramos-Alvarez I, Iordanskaia T, Mantey SA, Jensen RT. Bombesin Receptor Family Activation and CNS/Neural Tumors: Review of Evidence Supporting Possible Role for Novel Targeted Therapy. Front Endocrinol (Lausanne) 2021; 12:728088. [PMID: 34539578 PMCID: PMC8441013 DOI: 10.3389/fendo.2021.728088] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2021] [Accepted: 08/02/2021] [Indexed: 12/13/2022] Open
Abstract
G-protein-coupled receptors (GPCRs) are increasingly being considered as possible therapeutic targets in cancers. Activation of GPCR on tumors can have prominent growth effects, and GPCRs are frequently over-/ectopically expressed on tumors and thus can be used for targeted therapy. CNS/neural tumors are receiving increasing attention using this approach. Gliomas are the most frequent primary malignant brain/CNS tumor with glioblastoma having a 10-year survival <1%; neuroblastomas are the most common extracranial solid tumor in children with long-term survival<40%, and medulloblastomas are less common, but one subgroup has a 5-year survival <60%. Thus, there is an increased need for more effective treatments of these tumors. The Bombesin-receptor family (BnRs) is one of the GPCRs that are most frequently over/ectopically expressed by common tumors and is receiving particular attention as a possible therapeutic target in several tumors, particularly in prostate, breast, and lung cancer. We review in this paper evidence suggesting why a similar approach in some CNS/neural tumors (gliomas, neuroblastomas, medulloblastomas) should also be considered.
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Affiliation(s)
- Terry W. Moody
- Department of Health and Human Services, National Cancer Institute, Center for Cancer Training, Office of the Director, Bethesda, MD, United States
| | - Lingaku Lee
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
- Department of Gastroenterology, National Hospital Organization Kyushu Cancer Center, Fukuoka, Japan
| | - Irene Ramos-Alvarez
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Tatiana Iordanskaia
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Samuel A. Mantey
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Robert T. Jensen
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
- *Correspondence: Robert T. Jensen,
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2
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Bahmad HF, Poppiti RJ. Medulloblastoma cancer stem cells: molecular signatures and therapeutic targets. J Clin Pathol 2020; 73:243-249. [PMID: 32034059 DOI: 10.1136/jclinpath-2019-206246] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 12/12/2019] [Accepted: 12/16/2019] [Indexed: 12/11/2022]
Abstract
Medulloblastoma (MB) is the most common malignant primary intracranial neoplasm diagnosed in childhood. Although numerous efforts have been made during the past few years to exploit novel targeted therapies for this aggressive neoplasm, there still exist substantial hitches hindering successful management of MB. Lately, progress in cancer biology has shown evidence that a subpopulation of cells within the tumour, namely cancer stem cells (CSCs), are thought to be responsible for the resistance to most chemotherapeutic agents and radiation therapy, accounting for cancer recurrence. Hence, it is crucial to identify the molecular signatures and genetic aberrations that characterise those CSCs and develop therapies that specifically target them. In this review, we aim to give an overview of the main genetic and molecular cues that depict MB-CSCs and provide a synopsis of the novel therapeutic approaches that specifically target this population of cells to attain enhanced antitumorous effects and therefore overcome resistance to therapy.
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Affiliation(s)
- Hisham F Bahmad
- Arkadi M Rywlin MD Department of Pathology and Laboratory Medicine, Mount Sinai Medical Center, Miami Beach, Florida, USA.,Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - Robert J Poppiti
- Arkadi M Rywlin MD Department of Pathology and Laboratory Medicine, Mount Sinai Medical Center, Miami Beach, Florida, USA .,Herbert Wertheim College of Medicine, Florida International University, Miami, Florida, USA
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3
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Shah SS, Rodriguez GA, Musick A, Walters WM, de Cordoba N, Barbarite E, Marlow MM, Marples B, Prince JS, Komotar RJ, Vanni S, Graham RM. Targeting Glioblastoma Stem Cells with 2-Deoxy-D-Glucose (2-DG) Potentiates Radiation-Induced Unfolded Protein Response (UPR). Cancers (Basel) 2019; 11:cancers11020159. [PMID: 30709011 PMCID: PMC6406669 DOI: 10.3390/cancers11020159] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2019] [Revised: 01/24/2019] [Accepted: 01/29/2019] [Indexed: 01/09/2023] Open
Abstract
Glioblastoma (GBM) is the most common and aggressive primary brain tumor in adults, and despite optimized treatment options, median survival remains dismal. Contemporary evidence suggests disease recurrence results from expansion of a robustly radioresistant subset of GBM progenitor cells, termed GBM stem cells (GSCs). In this study, we utilized transmission electron microscopy to uncover ultrastructural effects on patient-derived GSC lines exposed to supratherapeutic radiotherapy levels. Elevated autophagosome formation and increased endoplasmic reticulum (ER) internal diameter, a surrogate for ER stress and activation of unfolded protein response (UPR), was uncovered. These observations were confirmed via protein expression through Western blot. Upon interrogating genomic data from an open-access GBM patient database, overexpression of UPR-related chaperone protein genes was inversely correlated with patient survival. This indicated controlled UPR may play a role in promoting radioresistance. To determine if potentiating UPR further can induce apoptosis, we exposed GSCs to radiation with an ER stress-inducing drug, 2-deoxy-D-glucose (2-DG), and found dose-dependent decreases in viability and increased apoptotic marker expression. Taken together, our results indicate GSC radioresistance is, in part, achieved by overexpression and overactivation of ER stress-related pathways, and this effect can be overcome via potentiation of UPR, leading to loss of GSC viability.
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Affiliation(s)
- Sumedh S Shah
- University of Miami Brain Tumor Initiative, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
- Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
| | - Gregor A Rodriguez
- University of Miami Brain Tumor Initiative, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
| | - Alexis Musick
- Dauer Electron Microscopy Laboratory, Department of Biology, University of Miami, Coral Gables, FL 33146, USA.
| | - Winston M Walters
- University of Miami Brain Tumor Initiative, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
| | - Nicolas de Cordoba
- University of Miami Brain Tumor Initiative, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
| | - Eric Barbarite
- University of Miami Brain Tumor Initiative, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
| | - Megan M Marlow
- University of Miami Brain Tumor Initiative, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
| | - Brian Marples
- University of Miami Brain Tumor Initiative, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
- Department of Radiation Oncology, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
- Sylvester Comprehensive Cancer Center, University of Miami Health System, Miami, FL 33136, USA.
| | - Jeffrey S Prince
- Dauer Electron Microscopy Laboratory, Department of Biology, University of Miami, Coral Gables, FL 33146, USA.
| | - Ricardo J Komotar
- University of Miami Brain Tumor Initiative, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
- Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
- Sylvester Comprehensive Cancer Center, University of Miami Health System, Miami, FL 33136, USA.
| | - Steven Vanni
- Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
| | - Regina M Graham
- University of Miami Brain Tumor Initiative, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
- Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
- Sylvester Comprehensive Cancer Center, University of Miami Health System, Miami, FL 33136, USA.
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4
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Distribution of cancer stem cells in two human brain gliomas. Oncol Lett 2018; 17:2123-2130. [PMID: 30719107 PMCID: PMC6351732 DOI: 10.3892/ol.2018.9824] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Accepted: 10/17/2018] [Indexed: 12/19/2022] Open
Abstract
There is compelling evidence that brain tumors, particularly glioblastoma multiforme (GBM), harbor a small population of cancer stem cells (CSCs). These CSCs have the ability to undergo self-renewal, initiate tumors in vivo, and are resistant to chemotherapy and radiation therapy. The present study determined the spatial distribution of CSCs within the donated brains of two deceased patients affected by glioblastoma multiforme. The following six grossly visible functional regions were identified: Necrotic tumor, viable solid tumor, infiltrating tumor edge, peritumoral normal brain, normal brain close to the tumor and normal brain distant from the tumor. Each region was snap-frozen, sectioned and immunostained for the CSC biomarkers prominin-1 (CD133) and sex-determining region Y-box 2 (SOX2). The percentages of CD133+ and SOX2+ cells within each region were determined. Different percentages of CD133+ and SOX2+ cells were identified in different regions. Significantly higher percentages of CD133+ and SOX2+ cells were indicated at the infiltrating tumor edge when compared with other areas. In summary, the spatial distributions of CSCs in these two brains with glioblastoma multiforme were similar, with the highest concentration being at the infiltrating tumor edge. This suggests that the edge of the tumor is the moving front for tumor progression and invasion, and should be targeted for therapeutic intervention.
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de la Rosa J, Sáenz Antoñanzas A, Shahi MH, Meléndez B, Rey JA, Castresana JS. Laminin-adherent versus suspension-non-adherent cell culture conditions for the isolation of cancer stem cells in the DAOY medulloblastoma cell line. Tumour Biol 2016; 37:12359-12370. [DOI: 10.1007/s13277-016-5119-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2016] [Accepted: 06/09/2016] [Indexed: 01/01/2023] Open
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Gastrin-Releasing Peptide Receptor Knockdown Induces Senescence in Glioblastoma Cells. Mol Neurobiol 2016; 54:888-894. [PMID: 26780458 DOI: 10.1007/s12035-016-9696-6] [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: 11/03/2015] [Accepted: 01/05/2016] [Indexed: 12/19/2022]
Abstract
Glioblastoma multiforme (GBM) is the most aggressive type of brain tumor, characterized by excessive cell proliferation, resistance to apoptosis, and invasiveness. Due to resistance to currently available treatment options, the prognosis for patients with GBM is very dismal. The activation of gastrin-releasing peptide receptors (GRPR) stimulates GBM cell proliferation, whereas GRPR antagonists induce antiproliferative effects in in vitro and in vivo experimental models of GBM. However, the role of GRPR in regulating other aspects of GBM cell function related to tumor progression remains poorly understood, and previous studies have not used RNA interference techniques as tools to examine GRPR function in GBM. Here, we found that stable GRPR knockdown by a lentiviral vector using a short hairpin interfering RNA sequence in human A172 GBM cells resulted in increased cell size and altered cell cycle dynamics consistent with cell senescence. These changes were accompanied by increases in the content of p53, p21, and p16, activation of epidermal growth factor receptors (EGFR), and a reduction in p38 content. These results increase our understanding of GRPR regulation of GBM cells and further support that GRPR may be a relevant therapeutic target in GBM.
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7
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Sarvi S, Mackinnon AC, Avlonitis N, Bradley M, Rintoul RC, Rassl DM, Wang W, Forbes SJ, Gregory CD, Sethi T. CD133+ cancer stem-like cells in small cell lung cancer are highly tumorigenic and chemoresistant but sensitive to a novel neuropeptide antagonist. Cancer Res 2014; 74:1554-65. [PMID: 24436149 DOI: 10.1158/0008-5472.can-13-1541] [Citation(s) in RCA: 139] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Small cell lung cancer (SCLC) is a highly aggressive malignancy with poor survival rates, with initial responses nearly invariably followed by rapid recurrence of therapy-resistant disease. Drug resistance in SCLC may be attributable to the persistence of a subpopulation of cancer stem-like cells (CSC) that exhibit multiple drug resistance. In this study, we characterized the expression of CD133, one important marker of CSC in other cancers, in SCLC cancer cells. CD133 expression correlated with chemoresistance and increased tumorigenicity in vitro and in vivo accompanied by increased expression of Akt/PKB and Bcl-2. CD133 expression was increased in mouse and human SCLC after chemotherapy, an observation confirmed in clinical specimens isolated longitudinally from a patient receiving chemotherapy. We discovered in CD133(+) SCLC cells, an increased expression of the mitogenic neuropeptide receptors for gastrin-releasing peptide and arginine vasopressin. Notably, these cells exhibited increased sensitivity to the growth inhibitory and proapoptotic effects of a novel broad spectrum neuropeptide antagonist (related to SP-G), which has completed a phase I clinical trial for SCLC. Our results offer evidence that this agent can preferentially target chemoresistant CD133(+) cells with CSC character in SCLC, emphasizing its potential utility for improving therapy in this setting.
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Affiliation(s)
- Sana Sarvi
- Authors' Affiliations: MRC Centre for Inflammation Research, The Queen's Medical Research Institute; MRC Centre for Regenerative Medicine; School of Chemistry, Joseph Black Building, University of Edinburgh, Edinburgh; Department of Thoracic Oncology, Papworth Hospital NHS Foundation Trust, Cambridge; and Department of Respiratory Medicine and Allergy, Kings College Denmark Hill Campus, London, United Kingdom
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8
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Affiliation(s)
- Rafael Roesler
- Department of Pharmacology, Institute for Basic Health Sciences, Cancer Research Laboratory, University Hospital Research Center (CPE-HCPA), Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil
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9
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Sassi FDA, Caesar L, Jaeger M, Nör C, Abujamra AL, Schwartsmann G, de Farias CB, Brunetto AL, Lopez PLDC, Roesler R. Inhibitory activities of trichostatin a in U87 glioblastoma cells and tumorsphere-derived cells. J Mol Neurosci 2014; 54:27-40. [PMID: 24464841 DOI: 10.1007/s12031-014-0241-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Accepted: 01/14/2014] [Indexed: 12/11/2022]
Abstract
Epigenetic alterations have been increasingly implicated in glioblastoma (GBM) pathogenesis, and epigenetic modulators including histone deacetylase inhibitors (HDACis) have been investigated as candidate therapies. GBMs are proposed to contain a subpopulation of glioblastoma stem cells (GSCs) that sustain tumor progression and therapeutic resistance and can form tumorspheres in culture. Here, we investigate the effects of the HDACi trichostatin A (TSA) in U87 GBM cultures and tumorsphere-derived cells. Using approaches that include a novel method to measure tumorsphere sizes and the area covered by spheres in GBM cultures, as well as a nuclear morphometric analysis, we show that TSA reduced proliferation and colony sizes, led to G2/M arrest, induced alterations in nuclear morphology consistent with cell senescence, and increased the protein content of GFAP, but did not affect migration, in cultured human U87 GBM cells. In cells expanded in tumorsphere assays, TSA reduced sphere formation and induced neuron-like morphological changes. The expression of stemness markers in these cells was detected by reverse transcriptase polymerase chain reaction. These findings indicate that HDACis can inhibit proliferation, survival, and tumorsphere formation, and promote differentiation of U87 GBM cells, providing further evidence for the development of HDACis as potential therapeutics against GBM.
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Affiliation(s)
- Felipe de Almeida Sassi
- Cancer Research Laboratory, University Hospital Research Center (CPE-HCPA), Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil
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10
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Li P, Lu X, Wang Y, Sun L, Qian C, Yan W, Liu N, You Y, Fu Z. MiR-181b suppresses proliferation of and reduces chemoresistance to temozolomide in U87 glioma stem cells. J Biomed Res 2013; 24:436-43. [PMID: 23554660 PMCID: PMC3596691 DOI: 10.1016/s1674-8301(10)60058-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2010] [Revised: 09/28/2010] [Accepted: 10/29/2010] [Indexed: 01/26/2023] Open
Abstract
MicroRNAs regulate self renewal and differentiation of cancer stem cells. There, we sought to identify the expression of miR-181b in glioma stem cells and investigate the biological effect of miR-181b on glioma stem cells in this study. MiR-181b expression was measured by real-time PCR in glioma stem cells isolated from U87 cells by FACS sorting. After miR-181b was overexpressed in U87 glioma stem cells by miR-181b lentiviral expression vector and/or treatment of temozolomide, secondary neurosphere assay, soft agar colony assay and MTT assay were performed. Compared with U87 cells, the expression of miR-181b was significantly decreased in U87 glioma stem cells. Overexpression of miR-181b decreased neurosphere formation by U87 glioma stem cells in vitro and suppressed colony formation in soft agar, and the cell growth inhibition rates increased in a time-dependent manner in U87 glioma stem cells infected with miR-181b lentivirus. Furthermore, miR-181b had a synergistic effect on temozolomide-induced inhibition of secondary neurosphere and soft agar colony, and on cell growth inhibition rates. MiR-181b functions as a tumor suppressor that suppresses proliferation and reduces chemoresistance to temozolomide in glioma stem cells.
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Affiliation(s)
- Ping Li
- Department of Neurosurgery, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China
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11
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Nör C, Sassi FA, de Farias CB, Schwartsmann G, Abujamra AL, Lenz G, Brunetto AL, Roesler R. The histone deacetylase inhibitor sodium butyrate promotes cell death and differentiation and reduces neurosphere formation in human medulloblastoma cells. Mol Neurobiol 2013; 48:533-43. [PMID: 23516101 DOI: 10.1007/s12035-013-8441-7] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Accepted: 03/08/2013] [Indexed: 01/07/2023]
Abstract
Increasing evidence suggests that alterations in epigenetic mechanisms regulating chromatin state play a role in the pathogenesis of medulloblastoma (MB), the most common malignant brain tumor of childhood. Histone deacetylase (HDAC) inhibitors, which increase chromatin relaxation, have been shown to display anticancer activities. Here we show that the HDAC inhibitor sodium butyrate (NaB) markedly increases cell death and reduces colony formation in human MB cell lines. In addition, NaB increased the mRNA expression of Gria2, a neuronal differentiation marker, in D283 and DAOY cells and reduced the number of neurospheres in D283 cell cultures. Finally, NaB reduced the viability of D283 cells when combined with etoposide. These data show that NaB displays pronounced inhibitory effects on the survival of human MB cells and suggest that NaB might potentiate the effects of etoposide. In addition, our study suggests that HDAC inhibition might promote the neuronal differentiation of MB cells and provides the first evidence that an HDAC inhibitor might suppress the expansion or survival of MB cancer stem cells.
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Affiliation(s)
- Carolina Nör
- Cancer Research Laboratory, University Hospital Research Center (CPE-HCPA), Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil
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Li Z, Lee JW, Mukherjee D, Ji J, Jeswani SP, Black KL, Yu JS. Immunotherapy targeting glioma stem cells--insights and perspectives. Expert Opin Biol Ther 2011; 12:165-78. [PMID: 22200324 DOI: 10.1517/14712598.2012.648180] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
INTRODUCTION Glioblastoma multiforme (GBM) is the most aggressive and lethal primary malignant brain tumor. Although progress has been made in current conventional therapies for GBM patients, the effect of these advances on clinical outcomes has been disappointing. Recent research into the origin of cancers suggest that GBM cancer stem cells (GSC) are the source of initial tumor formation, resistance to current conventional therapeutics and eventual patient relapse. Currently, there are very few studies that apply immunotherapy to target GSC. AREAS COVERED CD133, a cell surface protein, is used extensively as a surface marker to identify and isolate GSC in malignant glioma. We discuss biomarkers such as CD133, L1-cell adhesion molecule (L1-CAM), and A20 of GSC. We review developing novel treatment modalities, including immunotherapy strategies, to target GSC. EXPERT OPINION There are very few reports of preclinical studies targeting GSC. Identification and validation of unique molecular signatures and elucidation of signaling pathways involved in survival, proliferation and differentiation of GSC will significantly advance this field and provide a framework for the rational design of a new generation of antigen-specific, anti-GSC immunotherapy- and nanotechnology-based targeted therapyies. Combined with other therapeutic avenues, GSC-targeting therapies may represent a new paradigm to treat GBM patients.
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Affiliation(s)
- Zhenhua Li
- Maxine Dunitz Neurosurgical Institute, Cedars-Sinai Medical Center, 8361 West Third Street, Suite 800 E, Los Angeles, CA 90048, USA
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Extracellular ATP reduces tumor sphere growth and cancer stem cell population in glioblastoma cells. Purinergic Signal 2011; 8:39-48. [PMID: 21818572 DOI: 10.1007/s11302-011-9252-9] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2010] [Accepted: 07/18/2011] [Indexed: 10/18/2022] Open
Abstract
Glioblastoma is the most aggressive tumor in the CNS and is characterized by having a cancer stem cell (CSC) subpopulation essential for tumor survival. The purinergic system plays an important role in glioma growth, since adenosine triphosphate (ATP) can induce proliferation of glioma cells, and alteration in extracellular ATP degradation by the use of exogenous nucleotidases dramatically alters the size of gliomas in rats. The aim of this work was to characterize the effect of the purinergic system on glioma CSCs. Human U87 glioma cultures presented tumor spheres that express the markers of glioma cancer stem cells CD133, Oct-4, and Nanog. Messenger RNA of several purinergic receptors were differently expressed in spheres when compared to a cell monolayer not containing spheres. Treatment of human gliomas U87 or U343 as well as rat C6 gliomas with 100 μM of ATP reduced the number of tumor spheres when grown in neural stem cell medium supplemented with epidermal growth factor and basic fibroblast growth factor. Moreover, ATP caused a decline in the number of spheres observed in culture in a dose-dependent manner. ATP also reduces the expression of Nanog, as determined by flow cytometry, as well as CD133 and Oct-4, as analyzed by flow cytometry and RT-PCR in U87 cells. The differential expression of purinergic receptor in tumor spheres when compared to adherent cells and the effect of ATP in reducing tumor spheres suggest that the purinergic system affects CSC biology and that ATP may be a potential agonist for differentiation therapy.
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Roesler R, Brunetto AT, Abujamra AL, de Farias CB, Brunetto AL, Schwartsmann G. Current and emerging molecular targets in glioma. Expert Rev Anticancer Ther 2011; 10:1735-51. [PMID: 21080801 DOI: 10.1586/era.10.167] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Gliomas are the most common and lethal neurological cancers. Despite research efforts, the prognosis for patients with malignant gliomas remains poor. Advances in the understanding of cellular and molecular alterations in gliomas have led to the emergence of experimental molecularly targeted therapies. This article summarizes recent progress in the development of targeted therapies for glioma, focusing on emerging molecular targets, including neuropeptide and neurotrophin pathways, glutamate receptors, epigenetic mechanisms and glioma stem cell targets. Recent clinical trials of small molecules and antibodies targeted at growth factor pathways and intracellular signaling cascades are also discussed.
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Affiliation(s)
- Rafael Roesler
- Laboratory of Molecular Neuropharmacology, Department of Pharmacology, Institute for Basic Health Sciences, Federal University of Rio Grande do Sul, 90050-170 Porto Alegre, RS, Brazil.
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Abstract
A given cancer is produced by a unique combination of genetic alterations that target specific genes, most often leading to activation of oncogenes and inactivation of tumor suppressor genes. Traditional oncogenes, such as RasV12, are involved in maintaining pro-survival and proliferation signals activated in the cell. Several evidences suggest that cancer cells are addicted to oncogenes and that their inhibition has dramatic effects on cancer cells. Here, the hypothesis that oncogenes may be activated only transiently and that this short activation may be important for cancer formation by affecting the differentiation state of the cancer cells is presented. These "transient oncogenes" are overlooked in genomic or proteomic analysis due to their transient nature. Here we argue that transcription factors, such as the so called Yamanaka factors, capable of reprogramming cells to a less differentiated state, which normally happens to cancer cells, can function as transient oncogenes. Several published evidences are used to support the proposed hypothesis. Analysis and even targeting of this new class of oncogenes could have a great impact on cancer biology, treatment and, most importantly, prevention.
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Affiliation(s)
- G Lenz
- Department of Biophysics and Center of Biotechnology, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, Brazil.
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Expression of Hydroxyindole-O-Methyltransferase Enzyme in the Human Central Nervous System and in Pineal Parenchymal Cell Tumors. J Neuropathol Exp Neurol 2010; 69:498-510. [DOI: 10.1097/nen.0b013e3181db7d3c] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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17
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Gastrin-releasing peptide receptor content in human glioma and normal brain. Brain Res Bull 2010; 82:95-8. [DOI: 10.1016/j.brainresbull.2010.02.014] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2009] [Revised: 01/25/2010] [Accepted: 02/28/2010] [Indexed: 11/20/2022]
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Roesler R, Cornelio DB, Abujamra AL, Schwartsmann G. HER2 as a cancer stem-cell target. Lancet Oncol 2010; 11:225-6. [DOI: 10.1016/s1470-2045(09)70404-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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