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Gamble LD, Purgato S, Henderson MJ, Di Giacomo S, Russell AJ, Pigini P, Murray J, Valli E, Milazzo G, Giorgi FM, Cowley M, Ashton LJ, Bhalshankar J, Schleiermacher G, Rihani A, Van Maerken T, Vandesompele J, Speleman F, Versteeg R, Koster J, Eggert A, Noguera R, Stallings RL, Tonini GP, Fong K, Vaksman Z, Diskin SJ, Maris JM, London WB, Marshall GM, Ziegler DS, Hogarty MD, Perini G, Norris MD, Haber M. A G316A Polymorphism in the Ornithine Decarboxylase Gene Promoter Modulates MYCN-Driven Childhood Neuroblastoma. Cancers (Basel) 2021; 13:cancers13081807. [PMID: 33918978 PMCID: PMC8069650 DOI: 10.3390/cancers13081807] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Revised: 03/29/2021] [Accepted: 04/06/2021] [Indexed: 01/13/2023] Open
Abstract
Simple Summary Neuroblastoma is a devasting childhood cancer in which multiple copies (amplification) of the cancer-causing gene MYCN strongly predict poor outcome. Neuroblastomas are reliant on high levels of cellular components called polyamines for their growth and malignant behavior, and the gene regulating polyamine synthesis is called ODC1. ODC1 is often coamplified with MYCN, and in fact is regulated by MYCN, and like MYCN is prognostic of poor outcome. Here we studied a naturally occurring genetic variant or polymorphism that occurs in the ODC1 gene, and used gene editing to demonstrate the functional importance of this variant in terms of ODC1 levels and growth of neuroblastoma cells. We showed that this variant impacts the ability of MYCN to regulate ODC1, and that it also influences outcome in neuroblastoma, with the rarer variant associated with a better survival. This study addresses the important topic of genetic polymorphisms in cancer. Abstract Ornithine decarboxylase (ODC1), a critical regulatory enzyme in polyamine biosynthesis, is a direct transcriptional target of MYCN, amplification of which is a powerful marker of aggressive neuroblastoma. A single nucleotide polymorphism (SNP), G316A, within the first intron of ODC1, results in genotypes wildtype GG, and variants AG/AA. CRISPR-cas9 technology was used to investigate the effects of AG clones from wildtype MYCN-amplified SK-N-BE(2)-C cells and the effect of the SNP on MYCN binding, and promoter activity was investigated using EMSA and luciferase assays. AG clones exhibited decreased ODC1 expression, growth rates, and histone acetylation and increased sensitivity to ODC1 inhibition. MYCN was a stronger transcriptional regulator of the ODC1 promoter containing the G allele, and preferentially bound the G allele over the A. Two neuroblastoma cohorts were used to investigate the clinical impact of the SNP. In the study cohort, the minor AA genotype was associated with improved survival, while poor prognosis was associated with the GG genotype and AG/GG genotypes in MYCN-amplified and non-amplified patients, respectively. These effects were lost in the GWAS cohort. We have demonstrated that the ODC1 G316A polymorphism has functional significance in neuroblastoma and is subject to allele-specific regulation by the MYCN oncoprotein.
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Affiliation(s)
- Laura D. Gamble
- Children’s Cancer Institute, Lowy Cancer Research Centre, UNSW Australia, PO Box 81, Randwick, NSW 2031, Australia; (L.D.G.); (M.J.H.); (J.M.); (E.V.); (M.C.); (G.M.M.); (D.S.Z.); (M.D.N.)
| | - Stefania Purgato
- Department of Pharmacy and Biotechnology, University of Bologna, 40126 Bologna, Italy; (S.P.); (S.D.G.); (P.P.); (G.M.); (F.M.G.); (G.P.)
| | - Michelle J. Henderson
- Children’s Cancer Institute, Lowy Cancer Research Centre, UNSW Australia, PO Box 81, Randwick, NSW 2031, Australia; (L.D.G.); (M.J.H.); (J.M.); (E.V.); (M.C.); (G.M.M.); (D.S.Z.); (M.D.N.)
| | - Simone Di Giacomo
- Department of Pharmacy and Biotechnology, University of Bologna, 40126 Bologna, Italy; (S.P.); (S.D.G.); (P.P.); (G.M.); (F.M.G.); (G.P.)
| | - Amanda J. Russell
- Cancer Research Program, The Garvan Institute of Medical Research, Darlinghurst, NSW 2010, Australia;
| | - Paolo Pigini
- Department of Pharmacy and Biotechnology, University of Bologna, 40126 Bologna, Italy; (S.P.); (S.D.G.); (P.P.); (G.M.); (F.M.G.); (G.P.)
| | - Jayne Murray
- Children’s Cancer Institute, Lowy Cancer Research Centre, UNSW Australia, PO Box 81, Randwick, NSW 2031, Australia; (L.D.G.); (M.J.H.); (J.M.); (E.V.); (M.C.); (G.M.M.); (D.S.Z.); (M.D.N.)
| | - Emanuele Valli
- Children’s Cancer Institute, Lowy Cancer Research Centre, UNSW Australia, PO Box 81, Randwick, NSW 2031, Australia; (L.D.G.); (M.J.H.); (J.M.); (E.V.); (M.C.); (G.M.M.); (D.S.Z.); (M.D.N.)
| | - Giorgio Milazzo
- Department of Pharmacy and Biotechnology, University of Bologna, 40126 Bologna, Italy; (S.P.); (S.D.G.); (P.P.); (G.M.); (F.M.G.); (G.P.)
| | - Federico M. Giorgi
- Department of Pharmacy and Biotechnology, University of Bologna, 40126 Bologna, Italy; (S.P.); (S.D.G.); (P.P.); (G.M.); (F.M.G.); (G.P.)
| | - Mark Cowley
- Children’s Cancer Institute, Lowy Cancer Research Centre, UNSW Australia, PO Box 81, Randwick, NSW 2031, Australia; (L.D.G.); (M.J.H.); (J.M.); (E.V.); (M.C.); (G.M.M.); (D.S.Z.); (M.D.N.)
| | - Lesley J. Ashton
- Research Portfolio, University of Sydney, Sydney, NSW 2008, Australia;
| | - Jaydutt Bhalshankar
- SIREDO, Department of Paediatric, Adolescents and Young Adults Oncology and INSERM U830, Institut Curie, 26 rue d’Ulm, 75005 Paris, France; (J.B.); (G.S.)
| | - Gudrun Schleiermacher
- SIREDO, Department of Paediatric, Adolescents and Young Adults Oncology and INSERM U830, Institut Curie, 26 rue d’Ulm, 75005 Paris, France; (J.B.); (G.S.)
| | - Ali Rihani
- Center for Medical Genetics, Ghent University, C. Heymanslaan 10, 9000 Ghent, Belgium; (A.R.); (T.V.M.); (J.V.); (F.S.)
| | - Tom Van Maerken
- Center for Medical Genetics, Ghent University, C. Heymanslaan 10, 9000 Ghent, Belgium; (A.R.); (T.V.M.); (J.V.); (F.S.)
| | - Jo Vandesompele
- Center for Medical Genetics, Ghent University, C. Heymanslaan 10, 9000 Ghent, Belgium; (A.R.); (T.V.M.); (J.V.); (F.S.)
| | - Frank Speleman
- Center for Medical Genetics, Ghent University, C. Heymanslaan 10, 9000 Ghent, Belgium; (A.R.); (T.V.M.); (J.V.); (F.S.)
| | - Rogier Versteeg
- Department of Oncogenomics, Academic Medical Center, University of Amsterdam, 1100 Amsterdam, The Netherlands; (R.V.); (J.K.)
| | - Jan Koster
- Department of Oncogenomics, Academic Medical Center, University of Amsterdam, 1100 Amsterdam, The Netherlands; (R.V.); (J.K.)
| | - Angelika Eggert
- Department of Pediatric Hematology, Oncology and SCT, Charité-University Hospital Berlin, Campus Virchow-Klinikum, 10117 Berlin, Germany;
| | - Rosa Noguera
- Department of Pathology, Medical School, University of Valencia, 46010 Valencia, Spain;
- CIBERONC-INCLIVA, Biomedical Health Research Institute, 46010 Valencia, Spain
| | - Raymond L. Stallings
- Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, D02 YN77 Dublin 2, Ireland;
| | - Gian Paolo Tonini
- Neuroblastoma Laboratory, Fondazione Istituto di Ricerca Pediatrica Città della Speranza, 35127 Padova, Italy;
| | - Kwun Fong
- Thoracic Research Centre, University of Queensland, The Prince Charles Hospital, Brisbane, QLD 4032, Australia;
| | - Zalman Vaksman
- Division of Oncology and Center for Childhood Cancer Research, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA; (Z.V.); (S.J.D.); (J.M.M.); (M.D.H.)
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Sharon J. Diskin
- Division of Oncology and Center for Childhood Cancer Research, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA; (Z.V.); (S.J.D.); (J.M.M.); (M.D.H.)
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - John M. Maris
- Division of Oncology and Center for Childhood Cancer Research, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA; (Z.V.); (S.J.D.); (J.M.M.); (M.D.H.)
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Wendy B. London
- Dana-Farber/Boston Children’s Cancer and Blood Disorders Center, Harvard Medical School, Boston, MA 02215, USA;
| | - Glenn M. Marshall
- Children’s Cancer Institute, Lowy Cancer Research Centre, UNSW Australia, PO Box 81, Randwick, NSW 2031, Australia; (L.D.G.); (M.J.H.); (J.M.); (E.V.); (M.C.); (G.M.M.); (D.S.Z.); (M.D.N.)
- Kids Cancer Centre, Sydney Children’s Hospital, High St, Randwick, NSW 2031, Australia
| | - David S. Ziegler
- Children’s Cancer Institute, Lowy Cancer Research Centre, UNSW Australia, PO Box 81, Randwick, NSW 2031, Australia; (L.D.G.); (M.J.H.); (J.M.); (E.V.); (M.C.); (G.M.M.); (D.S.Z.); (M.D.N.)
- Kids Cancer Centre, Sydney Children’s Hospital, High St, Randwick, NSW 2031, Australia
| | - Michael D. Hogarty
- Division of Oncology and Center for Childhood Cancer Research, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA; (Z.V.); (S.J.D.); (J.M.M.); (M.D.H.)
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Giovanni Perini
- Department of Pharmacy and Biotechnology, University of Bologna, 40126 Bologna, Italy; (S.P.); (S.D.G.); (P.P.); (G.M.); (F.M.G.); (G.P.)
| | - Murray D. Norris
- Children’s Cancer Institute, Lowy Cancer Research Centre, UNSW Australia, PO Box 81, Randwick, NSW 2031, Australia; (L.D.G.); (M.J.H.); (J.M.); (E.V.); (M.C.); (G.M.M.); (D.S.Z.); (M.D.N.)
- Centre for Childhood Cancer Research, University of New South Wales, Sydney, NSW 2052, Australia
| | - Michelle Haber
- Children’s Cancer Institute, Lowy Cancer Research Centre, UNSW Australia, PO Box 81, Randwick, NSW 2031, Australia; (L.D.G.); (M.J.H.); (J.M.); (E.V.); (M.C.); (G.M.M.); (D.S.Z.); (M.D.N.)
- Correspondence: ; Tel.: +61-(02)-9385-2170
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Zinc and zinc-containing biomolecules in childhood brain tumors. J Mol Med (Berl) 2016; 94:1199-1215. [PMID: 27638340 DOI: 10.1007/s00109-016-1454-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 07/13/2016] [Accepted: 07/27/2016] [Indexed: 12/21/2022]
Abstract
Zinc ions are essential cofactors of a wide range of enzymes, transcription factors, and other regulatory proteins. Moreover, zinc is also involved in cellular signaling and enzymes inhibition. Zinc dysregulation, deficiency, over-supply, and imbalance in zinc ion transporters regulation are connected with various diseases including cancer. A zinc ion pool is maintained by two types of proteins: (i) zinc-binding proteins, which act as a buffer and intracellular donors of zinc and (ii) zinc transporters responsible for zinc fluxes into/from cells and organelles. The decreased serum zinc ion levels have been identified in patients suffering from various cancer diseases, including head and neck tumors and breast, prostate, liver, and lung cancer. On the contrary, increased zinc ion levels have been found in breast cancer and other malignant tissues. Zinc metalloproteomes of a majority of tumors including brain ones are still not yet fully understood. Current knowledge show that zinc ion levels and detection of certain zinc-containing proteins may be utilized for diagnostic and prognostic purposes. In addition, these proteins can also be promising therapeutic targets. The aim of the present work is an overview of the importance of zinc ions, zinc transporters, and zinc-containing proteins in brain tumors, which are, after leukemia, the second most common type of childhood cancer and the second leading cause of death in children after accidents.
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Somasundaram A, Ardanowski N, Opalak CF, Fillmore HL, Chidambaram A, Broaddus WC. Wilms tumor 1 gene, CD97, and the emerging biogenetic profile of glioblastoma. Neurosurg Focus 2015; 37:E14. [PMID: 25434383 DOI: 10.3171/2014.9.focus14506] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Glioblastoma multiforme (GBM) is the most common type of primary brain tumor, and current treatment regimens are only marginally effective. One of the most vexing and malignant aspects of GBM is its pervasive infiltration into surrounding brain tissue. This review describes the role of the Wilms tumor 1 gene (WT1) and its relationship to GBM. WT1 has several alternative splicing products, one of which, the KTS(+) variant, has been demonstrated to be involved in the transcriptional activation of a variety of oncogenes as well as the inhibition of tumor suppressor genes. Further, this paper will examine the relationship of WT1 with CD97, a gene that codes for an epidermal growth factor receptor family member, an adhesion G-protein-coupled receptor, thought to promote tumor invasiveness and migration. The authors suggest that further research into WT1 and CD97 will allow clinicians to begin to deal more effectively with the infiltrative behavior displayed by GBM and design new therapies that target this deadly disease.
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Affiliation(s)
- Aravind Somasundaram
- Department of Neurosurgery, Virginia Commonwealth University, Richmond, Virginia
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Kletzel M, Chou PM, Olszewski M, Rademaker AW, Khan S. Expression of Wilms tumor gene in high risk neuroblastoma: complementary marker to tyrosine hydroxylase for detection of minimal residual disease. Transl Pediatr 2015; 4:219-25. [PMID: 26835379 PMCID: PMC4729048 DOI: 10.3978/j.issn.2224-4336.2015.07.01] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Neuroblastoma (NB) is an enigmatic tumor that often presents with metastatic disease at diagnosis and it is this aggressive propensity which places it among the deadliest pediatric tumors despite intensive multimodal therapy including hematopoietic stem cell transplantation (HSCT). We have previously demonstrated that Wilms tumor 1 gene (WT1) is a surrogate marker of proliferation in leukemia. To determine the potential association between WT1 and a known marker of NB, tyrosine hydroxylase (TH) in this high risk group of patients. METHODS A total of 141 random samples from 34 patients were obtained, at diagnosis (n=27), during therapy (n=95), in clinical remission (n=13), and at the time of relapse (n=6). Quantitative RT-PCR was used for the evaluation of the level of gene expression using specific primers. RESULTS Although similar gene expressions were demonstrated in both controls when evaluating both genes, significant difference was found at each clinical time point. Furthermore, when comparing patient samples from diagnosis to clinical remission and diagnosis to clinical relapse, individual gene expression varied. WT1 demonstrated significance (P=0.0002) and insignificance (P=0.06) whereas TH remained non-significant (P=0.2, P=0.09) respectively. CONCLUSIONS WT1 gene is indicative of cellular proliferation in NB and for this reason it can be adjuvant to TH for the detection minimal residual disease (MRD).
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Affiliation(s)
- Morris Kletzel
- 1 Northwestern University Feinberg School of Medicine, Chicago Il, USA ; 2 Lurie Children's Hospital of Chicago Department of Hematology, Oncology and Transplant, Chicago Il, USA ; 3 Stem Cell Transplant Research Laboratory, Chicago Il, USA ; 4 Lurie Children's Hospital of Chicago Department of Pathology, Chicago Il, USA
| | - Pauline M Chou
- 1 Northwestern University Feinberg School of Medicine, Chicago Il, USA ; 2 Lurie Children's Hospital of Chicago Department of Hematology, Oncology and Transplant, Chicago Il, USA ; 3 Stem Cell Transplant Research Laboratory, Chicago Il, USA ; 4 Lurie Children's Hospital of Chicago Department of Pathology, Chicago Il, USA
| | - Marie Olszewski
- 1 Northwestern University Feinberg School of Medicine, Chicago Il, USA ; 2 Lurie Children's Hospital of Chicago Department of Hematology, Oncology and Transplant, Chicago Il, USA ; 3 Stem Cell Transplant Research Laboratory, Chicago Il, USA ; 4 Lurie Children's Hospital of Chicago Department of Pathology, Chicago Il, USA
| | - Alfred W Rademaker
- 1 Northwestern University Feinberg School of Medicine, Chicago Il, USA ; 2 Lurie Children's Hospital of Chicago Department of Hematology, Oncology and Transplant, Chicago Il, USA ; 3 Stem Cell Transplant Research Laboratory, Chicago Il, USA ; 4 Lurie Children's Hospital of Chicago Department of Pathology, Chicago Il, USA
| | - Sana Khan
- 1 Northwestern University Feinberg School of Medicine, Chicago Il, USA ; 2 Lurie Children's Hospital of Chicago Department of Hematology, Oncology and Transplant, Chicago Il, USA ; 3 Stem Cell Transplant Research Laboratory, Chicago Il, USA ; 4 Lurie Children's Hospital of Chicago Department of Pathology, Chicago Il, USA
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Parenti R, Salvatorelli L, Musumeci G, Parenti C, Giorlandino A, Motta F, Magro G. Wilms' tumor 1 (WT1) protein expression in human developing tissues. Acta Histochem 2015; 117:386-96. [PMID: 25858532 DOI: 10.1016/j.acthis.2015.03.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2014] [Revised: 03/06/2015] [Accepted: 03/14/2015] [Indexed: 12/14/2022]
Abstract
Several genes playing crucial roles in human development often reproduce a key role also during the onset and progression of malignant tumors. WT1, a transcription factor expressed with a dynamic pattern during human development, has either oncogenic or suppressor tumor properties. A detailed analysis of the immunohistochemical profile of WT1 protein in human developmental tissues could be exploitable as the rational for better understanding its role in cancerogenesis and planning innovative WT1-based therapeutic approaches. This review focuses on the dynamic immunohistochemical expression and distribution of WT1 protein during human ontogenesis, providing illustrations and discussion on the most relevant findings. The possibility that WT1 nuclear/cytoplasmic expression in some tumors mirrors its normal developmental regulation will be emphasized.
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Parenti R, Puzzo L, Vecchio GM, Gravina L, Salvatorelli L, Musumeci G, Vasquez E, Magro G. Immunolocalization of Wilms' Tumor protein (WT1) in developing human peripheral sympathetic and gastroenteric nervous system. Acta Histochem 2014; 116:48-54. [PMID: 23791475 DOI: 10.1016/j.acthis.2013.05.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Revised: 05/12/2013] [Accepted: 05/13/2013] [Indexed: 01/06/2023]
Abstract
Developmental expression of Wilms' tumor gene (WT1) and protein is crucial for cell proliferation, apoptosis, differentiation and cytoskeletal architecture regulation. Recently, a potential role of WT1 has been suggested in the development of neural tissue and in neurodegenerative disorders. We have investigated immunohistochemically the developmentally regulated expression and distribution of WT1 in the human fetal peripheral sympathetic nervous system (PSNS) and the gastro-enteric nervous system (GENS) from weeks 8 to 28 gestational age. WT1 expression was restricted to the cytoplasm of sympathetic neuroblasts, while it progressively disappeared with advancing morphologic differentiation of these cells along both ganglionic and chromaffin cell lineages. In adult tissues, both ganglion and chromaffin cells lacked any WT1 expression. These findings show that WT1 is a reliable marker of human sympathetic neuroblasts, which can be used routinely in formalin-fixed, paraffin-embedded tissues. The progressive loss of WT1 in both ganglion and chromaffin cells, suggests its potential repressor role of differentiation in a precise temporal window during the development of the human PSNS and GENS.
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Wilms' tumor gene 1: a possible new proangiogenic factor in Hodgkin lymphoma. Appl Immunohistochem Mol Morphol 2013; 21:177-80. [PMID: 22688351 DOI: 10.1097/pai.0b013e318259852a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
INTRODUCTION Wilms' tumor gene 1 (WT1) was recently found to play a role in solid and hematologic malignancies and serves as a marker of prognosis and minimal residual disease in acute leukemia. WT1 was also found to be involved in tumor angiogenesis. There are no data concerning the involvement of WT1 in angiogenesis in lymphoproliferative tumors. The aim of this study was to explore the involvement of WT1 in Hodgkin lymphoma. METHODS The expression of WT1, neuropilin 1, and VEGF was tested by immunohistochemistry in lymph nodes biopsies of 20 Hodgkin patients and 7 reactive lymph nodes. RESULTS WT1 was expressed in endothelial cells, in 95% of the malignant lymph nodes. The average of WT1 expression scale was higher in the malignant lymph nodes than in reactive lymph nodes. We found a positive correlation between WT1 expression scale and the angiogenesis scale (0.53) that was statistically significant (P<0.05). As the number of vessels increases, the expression of WT1 is more intense. CONCLUSIONS We found, for the first time, that WT1 is expressed in endothelial cells in Hodgkin lymphoma. The clinical implications of these findings should be tested in a future study.
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Parenti R, Perris R, Vecchio GM, Salvatorelli L, Torrisi A, Gravina L, Magro G. Immunohistochemical expression of Wilms' tumor protein (WT1) in developing human epithelial and mesenchymal tissues. Acta Histochem 2013; 115:70-5. [PMID: 22673530 DOI: 10.1016/j.acthis.2012.04.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2012] [Revised: 04/27/2012] [Accepted: 04/30/2012] [Indexed: 10/28/2022]
Abstract
The Wilms' tumor (WT1) gene and its protein product are known to exhibit a dynamic expression profile during development and in the adult organism. Apart from a nuclear expression observed in the urogenital system, its precise localization in other developing human tissues is still largely unknown. Accordingly, the aim of this study was to investigate immunohistochemically the temporal and spatial distribution of WT1 in epithelial and mesenchymal developing human tissues from gestational weeks 7-24. For this purpose we used antibodies against the N-terminal of WT1. As might be expected, WT1 nuclear expression was observed in mesonephric/metanephric glomeruli, metanephric blastema, celom-derived membranes (pleura, peritoneum, serosal surfaces) and sex cords. With regard to mesenchymal tissues, a similar nuclear staining was also obtained in the mesenchyme surrounding Müllerian and Wolffian ducts, as well as in the submesothelial mesenchymal cells of all celomatic-derived membranes. The most striking finding was the detection of strong WT1 cytoplasmic immunostaining in developing skeletal and cardiac muscle cells and endothelial cells. The tissue-specific expression of WT1, together with its different nuclear/cytoplasmic localization, both suggest that WT1 protein may have shuttling properties, acting as a protein with complex regulator activity in transcriptional/translation processes during human ontogenesis. The reported cytoplasmic expression of WT1 in human rhabdomyosarcomas and in many vascular tumors strongly suggests an oncofetal expression of this protein. Although not specific, WT1 cytoplasmic expression can be used as a marker of skeletal muscle and endothelial differentiation in an appropriate morphological context.
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Abstract
BACKGROUND/PURPOSE The oncogenic properties of the Wilms' tumor gene (WT1) have recently been reported in various malignancies. However, the role of WT1 in pediatric tumors is unclear. To elucidate the role of WT1 in the development of neuroblastoma (NB), we examined the WT1 expression in NB and the effect of WT1 suppression on NB cell proliferation. METHODS We examined the expression of the WT1 protein in 20 NBs and 5 ganglioneuromas (GNs) by performing immunohistochemical analysis. We determined WT1 messenger RNA expression in 22 NBs, 5 GNs, and 4 NB cell lines by real-time reverse transcription polymerase chain reaction. We studied the effects of WT1 suppression on cell proliferation using small interfering RNA against WT1. RESULTS Expression of WT1 was higher in mature ganglionic cells, and in the immunohistochemical analysis, the WT1 positivity for GNs was significantly higher than that for NBs (P < .01). The level of WT1 messenger RNA expression did not correlate with histologic grade, clinical stage, and prognosis of the tumor. Knockdown of WT1 gene promoted the proliferation of NB69 cells (P < .01). CONCLUSIONS The WT1 may govern cell differentiation and suppress cell proliferation in NB. The WT1 does not act as an oncogene, but it may participate in the maturation of NB.
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Clark AJ, Ware JL, Chen MY, Graf MR, Van Meter TE, Dos Santos WG, Fillmore HL, Broaddus WC. Effect of WT1 gene silencing on the tumorigenicity of human glioblastoma multiforme cells. J Neurosurg 2010; 112:18-25. [PMID: 19392599 DOI: 10.3171/2008.11.jns08368] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT Wilms tumor 1 (WT1) is overexpressed in many human cancers, including glioblastoma multiforme (GBM). In another study, the authors showed that transient WT1 silencing increases the radiosensitivity of glioma cells. Studies of nonglioma cell lines have demonstrated that WT1 promotes cell proliferation and survival; however, this ability has not been rigorously analyzed in human GBM. METHODS The authors tested the efficacy of 2 sequences of short hairpin RNA (shRNA) directed against WT1 in U251MG human GBM cells and found that 1 sequence was capable of stably silencing WT1 expression. They then evaluated the effect of WT1 silencing on cellular proliferation, invasion, and in vivo tumor formation. RESULTS Stable WT1-shRNA expression significantly decreased the proliferation of U251MG cells in vitro as demonstrated by both an adenosine 5'-triphosphate-based viability assay and tritiated thymidine uptake. Furthermore, stable WT1 silencing caused significantly slower growth after the subcutaneous inoculation of tumor cells in the flanks of athymic nude mice and was associated with an increased latency period. CONCLUSIONS Data in this study provide proof of the principle that downregulation of WT1 causes decreased tumorigenicity of a GBM cell line in vitro and in vivo and suggest that WT1 is a promising target for novel molecular GBM therapies, perhaps in combination with standard treatment modalities.
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Affiliation(s)
- Aaron J Clark
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Medical College of Virginia Campus, Richmond, Virginia 23298-0631, USA
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Jacobs JFM, Coulie PG, Figdor CG, Adema GJ, de Vries IJM, Hoogerbrugge PM. Targets for active immunotherapy against pediatric solid tumors. Cancer Immunol Immunother 2009; 58:831-41. [PMID: 19009292 PMCID: PMC11030767 DOI: 10.1007/s00262-008-0619-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2008] [Accepted: 10/22/2008] [Indexed: 02/06/2023]
Abstract
The potential role of antibodies and T lymphocytes in the eradication of cancer has been demonstrated in numerous animal models and clinical trials. In the last decennia new strategies have been developed for the use of tumor-specific T cells and antibodies in cancer therapy. Effective anti-tumor immunotherapy requires the identification of suitable target antigens. The expression of tumor-specific antigens has been extensively studied for most types of adult tumors. Pediatric patients should be excellent candidates for immunotherapy since their immune system is more potent and flexible as compared to that of adults. So far, these patients do not benefit enough from the progresses in cancer immunotherapy, and one of the reasons is the paucity of tumor-specific antigens identified on pediatric tumors. In this review we discuss the current status of cancer immunotherapy in children, focusing on the identification of tumor-specific antigens on pediatric solid tumors.
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Affiliation(s)
- J F M Jacobs
- Department of Pediatric Hemato-oncology, Radboud University Medical Centre Nijmegen, Nijmegen, The Netherlands.
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Pfuhl T, Mamiani A, Dürr M, Welter S, Stieber J, Ankara J, Liss M, Dobner T, Schmitt A, Falkai P, Kremmer E, Jung V, Barth S, Grässer FA. The LARK/RBM4a protein is highly expressed in cerebellum as compared to cerebrum. Neurosci Lett 2008; 444:11-5. [DOI: 10.1016/j.neulet.2008.08.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2008] [Revised: 07/04/2008] [Accepted: 08/05/2008] [Indexed: 10/21/2022]
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13
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Schittenhelm J, Beschorner R, Simon P, Tabatabai G, Herrmann C, Schlaszus H, Capper D, Weller M, Meyermann R, Mittelbronn M. Diagnostic value of WT1 in neuroepithelial tumours. Neuropathol Appl Neurobiol 2008; 35:69-81. [PMID: 18466223 DOI: 10.1111/j.1365-2990.2008.00957.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIMS Currently, clinical trials using WT1 (Wilms tumour gene) peptide vaccines are conducted in haematopoietic malignancies and solid cancers. Single reports showed that the Wilms tumour gene product WT1 is also expressed in astrocytic neoplasms. Our aim was to investigate WT1 expression in a large cohort of various neuroepithelial tumours of different World Health Organization (WHO) grades and in normal central nervous system (CNS) tissue specimens to test its potential value as a diagnostic marker. METHODS Specimens were assessed by RT-PCR, Western blotting and immunohistochemistry. The samples investigated in our study consisted of 334 human neuroepithelial tumours, among those 33 oligodendrogliomas, 219 astrocytomas (including 105 glioblastomas) and 47 ependymomas. RESULTS Our results showed a de novo WT1 expression in neuroepithelial tumours. In diffuse astrocytomas and ependymomas, WT1 expression increased significantly with the grade of malignancy. In contrast, no significant difference was seen between WHO grade-II and -III oligodendrogliomas. Controlling for WHO grade, the comparison of oligodendrogliomas with ependymal and astrocytic tumours showed higher expression values for the latter. CONCLUSIONS Our study shows that WT1 is expressed de novo in numerous neuroepithelial tumours and increases with the grade of malignancy. These results suggest an important role of WT1 in tumourigenesis and progression in human brain tumours.
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Affiliation(s)
- J Schittenhelm
- Institute of Brain Research, University of Tuebingen, Tuebingen, Germany
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14
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Clark AJ, Dos Santos WG, McCready J, Chen MY, Van Meter TE, Ware JL, Wolber SB, Fillmore H, Broaddus WC. Wilms tumor 1 expression in malignant gliomas and correlation of +KTS isoforms with p53 status. J Neurosurg 2007; 107:586-92. [PMID: 17886559 DOI: 10.3171/jns-07/09/0586] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Object
The WT1 gene is overexpressed in many types of human cancer. It has been demonstrated that Wilms tumor 1 (WT1) promotes tumor cell proliferation and survival in some cell lines by inhibiting p53-mediated apoptosis; however, this relationship has not been investigated in gliomas. The goal in this study was to characterize the expression pattern of WT1 in human gliomas and to determine if a correlation exists between WT1 expression and p53 status.
Methods
The authors screened nine malignant glioma cell lines, 50 glioblastoma multiforme (GBM) samples, and 16 lower-grade glial tumors for WT1 expression.
Results
Five of nine cell lines, 44 of 50 GBM samples, and 13 of 16 lower-grade gliomas expressed WT1 mRNA on reverse transcriptase polymerase chain reaction (PCR) analysis. Expression of WT1 was not detected in normal astrocytes. Two WT1 isoforms, +/+ and −/+, were expressed in the majority of these samples. Real-time PCR analysis of the GBM cell lines revealed that the level of WT1 mRNA ranged from 6.33 to 214.70 ng per ng 18S ribosomal RNA. The authors screened the GBM samples for p53 mutation by using PCR and single-stranded conformational polymorphism analysis, and they demonstrated an association between WT1 expression and p53 status. Tumors that contained wild-type p53 were significantly more likely to express WT1 than tumors that contained mutant p53.
Conclusions
The presence of WT1 in glioma cell lines and the majority of primary tumor samples and its absence in normal astrocytes support the suggestion that WT1 expression is important in glioma biology.
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Affiliation(s)
- Aaron J Clark
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Medical College of Virginia Campus, Richmond, Virginia 23298-0631, USA
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15
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Yang L, Han Y, Suarez Saiz F, Saurez Saiz F, Minden MD. A tumor suppressor and oncogene: the WT1 story. Leukemia 2007; 21:868-76. [PMID: 17361230 DOI: 10.1038/sj.leu.2404624] [Citation(s) in RCA: 324] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The Wilms' tumor 1 (WT1) gene encodes a transcription factor important for normal cellular development and cell survival. The initial discovery of WT1 as the causative gene in an autosomal-recessive condition identified it as a tumor suppressor gene whose mutations are associated with urogenital disease and the development of kidney tumors. However, this view is not in keeping with the frequent finding of wild-type, full-length WT1 in human leukemia, breast cancer and several other cancers including the majority of Wilms' tumors. Rather, these observations suggest that in those conditions, WT1 has an oncogenic role in tumor formation. In this review, we explore the literature supporting both views of WT1 in human cancer and in particular human leukemias. To understand the mechanism by which WT1 can do this, we will also examine its functional activity as a transcription factor and the influence of protein partners on its dual behavior.
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Affiliation(s)
- L Yang
- Department of Cellular and Molecular Biology, Ontario Cancer Institute, University Health Network, Toronto, Ontario, Canada
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16
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Clark AJ, Chan DC, Chen MY, Fillmore H, Dos Santos WG, Van Meter TE, Graf MR, Broaddus WC. Down-regulation of Wilms’ tumor 1 expression in glioblastoma cells increases radiosensitivity independently of p53. J Neurooncol 2007; 83:163-72. [PMID: 17206472 DOI: 10.1007/s11060-006-9317-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2006] [Accepted: 12/06/2006] [Indexed: 11/25/2022]
Abstract
The Wilms' tumor 1 (WT1) gene is overexpressed in human glioblastoma and correlates with wild-type p53 status. In other cell types, WT1 inhibits p53-mediated apoptosis in response to DNA damaging agents. However, neither this interaction nor the relationship between WT1 and radiosensitivity has been studied in glioblastoma. To study this interaction, we generated LN-229 glioma cell lines (p53 mutant) stably expressing WT1 isoforms and induced apoptosis by transfecting with different doses of wild-type p53 plasmid expression vector. Constitutive expression of WT1 did not protect against exogenous p53-mediated apoptosis. Likewise, WT1 expression did not protect against endogenous p53-mediated cell death induced by radiotherapy in U87MG cells, which contain functional wild-type p53. We then tested the efficacy of WT1 siRNA in inhibiting WT1 expression and its effect on radiosensitivity. In T98G and LN-18 glioma cells, which possess p53 mutations, WT1 siRNA decreased WT1 protein to almost undetectable levels by 96-h post-transfection. Furthermore, WT1 siRNA transfection caused a significantly larger decrease in viability following irradiation than was seen in untransfected cells in both cell lines after treatment with ED50 of ionizing radiation. In conclusion, WT1 overexpression did not protect against p53-mediated apoptosis or ionizing radiation induced cell death. WT1 siRNA increased the radiosensitivity of two human glioma cell lines independently of p53. Anti-WT1 strategies may, therefore, prove useful in improving the response of glioblastoma to radiotherapy, thus potentially improving patient survival.
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Affiliation(s)
- Aaron J Clark
- Department of Neurosurgery, Virginia Commonwealth University, Medical College of Virginia Campus, Richmond, VA 23298-0631, USA
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17
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Sarfstein R, Werner H. The WT1 Wilms' tumor suppressor gene is a downstream target for insulin-like growth factor-I (IGF-I) action in PC12 cells. J Neurochem 2006; 99:818-26. [PMID: 16911581 DOI: 10.1111/j.1471-4159.2006.04119.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The biological actions of the insulin-like growth factors, IGF-I and IGF-II, are mediated by the ligand-induced activation of the IGF-I receptor (IGF-IR), a transmembrane heterotetramer linked to the ras-raf-mitogen-activated protein kinase (MAPK) and phosphatidyl inositol 3 kinase (PI3K)-protein kinase B (PKB)/Akt signal transduction cascades. The Wilms' tumor suppressor gene (wt1) encodes a zinc finger transcription factor, WT1, which has been implicated in various cellular processes including proliferation, differentiation and apoptosis. In the present study we demonstrated that IGF-I modulates the WT1 gene expression in neurally derived PC12 cells in a dose- and time-dependent manner. This effect was mediated through both the MAPK and PI3-kinase signaling pathways, as shown by the ability of the specific inhibitors UO126 and LY294002 to abrogate IGF-I action. Moreover, using RT-PCR and transient transfection assays, we demonstrated that the IGF-I effect was associated with corresponding changes in WT1 mRNA levels and WT1 promoter activity. In addition, the results of the present study revealed that high WT1 levels were associated with the induction of apoptosis, whereas low WT1 levels were correlated with the inhibition of apoptosis, as demonstrated by poly ADP ribose polymerase (PARP) cleavage, Bax expression, Annexin V-FITC staining, and by the use of antisense oligonucleotides against WT1. In summary, our results show that the wt1 gene is a novel target for IGF-I action in neurally derived cells.
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Affiliation(s)
- Rive Sarfstein
- Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
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18
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Schumacher V, Thumfart J, Drechsler M, Essayie M, Royer-Pokora B, Querfeld U, Müller D. A novel WT1 missense mutation presenting with Denys–Drash syndrome and cortical atrophy. Nephrol Dial Transplant 2005; 21:518-21. [PMID: 16303781 DOI: 10.1093/ndt/gfi285] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Valérie Schumacher
- Institute of Human Genetics, Heinrich-Heine University Düsseldorf , Germany
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19
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Sebire NJ, Gibson S, Rampling D, Williams S, Malone M, Ramsay AD. Immunohistochemical findings in embryonal small round cell tumors with molecular diagnostic confirmation. Appl Immunohistochem Mol Morphol 2005; 13:1-5. [PMID: 15722786 DOI: 10.1097/00129039-200503000-00001] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The diagnosis of pediatric tumors relies heavily on immunohistochemical staining of small tissue biopsies, since many entities share a "small blue cell" phenotype. More recently, molecular genetic analysis for detection of specific gene fusion products has become available. With the increased use of such molecular techniques, the authors have noted that tumors with proven molecular diagnoses can exhibit unusual patterns of immunohistochemical staining. This study examines pediatric tumors with a "small blue cell" phenotype in which molecular diagnoses were available where applicable. A panel of immunohistochemical stains was performed (S100, CD56, NB84, CD99 [MIC2], Bcl-2, CD117, CD34, desmin, MNF116, and WT1). In the 370 sections from 37 cases, all primitive neuroectodermal tumors, with and without the presence of t(11;22), demonstrated uniform membranous membrane staining with CD99 (MIC2) and focal staining with CD56, NB84, MNF116, and WT1. All rhabdomyosarcomas, both alveolar and embryonal, demonstrated uniform desmin, CD56, and cytoplasmic WT1 immunostaining. Desmoplastic small round cell tumors showed positive cytokeratin staining, with half having "dot-like" cytoplasmic desmin and WT1 positivity; some showed focal positivity for NB84, CD99, and Bcl-2. The "undifferentiated" sarcomas showed the widest range of staining, with no marker staining all cases. Neuroblastomas exhibited uniform strong staining for CD56 and NB84 and marked cytoplasmic Bcl-2 positivity, and some cases showed cytoplasmic WT1 expression. Blastematous Wilms' tumors showed uniform strong membranous staining for CD56, uniform cytoplasmic staining for Bcl-2, and nuclear expression of WT1. Embryonal pediatric malignancies can demonstrate apparently nonspecific expression patterns for several antigens, which may reflect developmental immaturity rather than specific differentiation pathways.
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Affiliation(s)
- Neil J Sebire
- Department of Paediatric Pathology, Great Ormond Street Hospital, London, United Kingdom.
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20
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Oji Y, Suzuki T, Nakano Y, Maruno M, Nakatsuka SI, Jomgeow T, Abeno S, Tatsumi N, Yokota A, Aoyagi S, Nakazawa T, Ito K, Kanato K, Shirakata T, Nishida S, Hosen N, Kawakami M, Tsuboi A, Oka Y, Aozasa K, Yoshimine T, Sugiyama H. Overexpression of the Wilms' tumor gene WT1 in primary astrocytic tumors. Cancer Sci 2004; 95:822-7. [PMID: 15504250 DOI: 10.1111/j.1349-7006.2004.tb02188.x] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Expression of the Wilms' tumor gene W T1 in primary astrocytic tumors was examined using a quantitative real-time reverse transcriptase-polymerase chain reaction (RT-PCR) or immunohistochemistry. Real-time RT-PCR showed that W T1 mRNA was expressed at various levels in all of the 25 astrocytic tumors examined. Immunohistochemical analysis showed that W T1 protein was expressed in 5 of 6 low-grade astrocytic tumors (grade I-II) and all of 18 high-grade ones (grade III-IV), and that expression levels of W T1 protein in high-grade tumors were significantly higher than those in low-grade ones. W T1 protein was not detected in the normal glial cells contained in the tumor specimens. Furthermore, treatment with W T1 antisense oligomers specifically inhibited growth of glioblastoma cell lines, U87-MG, A172, and T-98G. These results may indicate that the W T1 gene plays an important role in tumorigenesis of primary astrocytic tumors.
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Affiliation(s)
- Yusuke Oji
- Department of Bioinformatics, Osaka University Graduate School of Medicine, 1-7 Yamada-Oka, Suita, Osaka 565-0871, Japan
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21
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Koesters R, Linnebacher M, Coy JF, Germann A, Schwitalle Y, Findeisen P, von Knebel Doeberitz M. WT1 is a tumor-associated antigen in colon cancer that can be recognized by in vitro stimulated cytotoxic T cells. Int J Cancer 2004; 109:385-92. [PMID: 14961577 DOI: 10.1002/ijc.11721] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The Wilms' tumor suppressor gene (WT1) has been shown to be overexpressed in acute and chronic leukemias and in a variety of solid human malignancies, including cancers of the breast and lung. In our present study, we investigated the potential role of WT1 gene in human colon cancer. WT1 mRNA and protein expression was analyzed in a panel of human colon cancer cell lines and primary colon carcinomas by RT-PCR and Western blot analysis, respectively. A mutational screen of WT1' zinc-finger region was carried out by sequence analysis. Finally, using peptide-stimulated cytotoxic T cells it was investigated whether WT1-expressing colon tumor cells are a potential target for antigen-specific immunotherapy. Medium to high abundant levels of WT1 mRNA were detected by RT-PCR in 10 of 12 (83%) colon cell lines and by quantitative, real-time RT-PCR in 13 of 15 (87%) primary tumors, whereas only very low levels of expression were found in 2 primary tumors. Interestingly, however, low levels of WT1 mRNA were also detected in all samples derived from normal colon mucosa. When RT-PCR products were examined by sequence analysis, both +KTS and -KTS splice isoforms but no zinc-finger mutations were found, suggesting that the wild-type form of the WT1 gene is expressed. To determine whether the WT1 protein can serve as a target antigen for immunotherapy, 2 HLA-A2.1-restricted WT1 peptides (Db126 and WH187) were used for the in vitro induction of WT1-specific cytotoxic T lymphocytes (CTLs). The WH187-specific CTLs not only lysed target cells pulsed exogenously with cognate peptide but also WT1-expressing colon tumor cells in a HLA-restricted manner. These findings identify the WT1 protein as an attractive target for the development of antigen-specific immunotherapy in human colon cancer.
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Affiliation(s)
- Robert Koesters
- Institute of Molecular Pathology, University of Heidelberg, Heidelberg, Germany
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22
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Abstract
Although originally identified as a tumor suppressor gene, WT1 is overexpressed in a variety of hematologic malignancies and solid tumors, including acute leukemia, breast cancer, malignant mesothelioma, renal cell carcinoma, and others. Overexpression of both wild-type and mutant WT1 has been reported. In some cases, this finding represents overexpression of a gene that should be expressed at lower levels, but in other cases, WT1 is expressed at high levels in a tissue type in which there is normally no expression at all. In this review, the mechanisms of altered WT1 expression are explored, including changes in promoter methylation. WT1 target genes that may be important for oncogenesis are discussed, as is the use of WT1 expression as a diagnostic tool. The prognostic implications of altered WT1 expression and the potential for immunotherapy aimed at WT1 are also discussed.
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Affiliation(s)
- David M Loeb
- Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, Maryland, USA
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