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Nourbakhsh A, Dinh CT. Updates on Tumor Biology in Vestibular Schwannoma. Otolaryngol Clin North Am 2023; 56:421-434. [PMID: 37121611 DOI: 10.1016/j.otc.2023.02.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Vestibular schwannomas (VSs) are benign tumors that develop after biallelic inactivation of the neurofibromatosis type 2 (NF2) gene that encodes the tumor suppressor merlin. Merlin inactivation leads to cell proliferation by dysregulation of receptor tyrosine kinase signaling and other intracellular pathways. In VS without NF2 mutations, dysregulation of non-NF2 genes can promote pathways favoring cell proliferation and tumorigenesis. The tumor microenvironment of VS consists of multiple cell types that influence VS tumor biology through complex intercellular networking and communications.
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Affiliation(s)
- Aida Nourbakhsh
- Department of Otolaryngology, University of Miami Miller School of Medicine, 1120 Northwest 14th Street, Suite 579, Miami, FL 33136, USA; Sylvester Comprehensive Cancer Center, 1475 Northwest 12th Avenue, Miami, FL 33136, USA
| | - Christine T Dinh
- Department of Otolaryngology, University of Miami Miller School of Medicine, 1120 Northwest 14th Street, Suite 579, Miami, FL 33136, USA; Sylvester Comprehensive Cancer Center, 1475 Northwest 12th Avenue, Miami, FL 33136, USA.
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2
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Ghalavand MA, Asghari A, Farhadi M, Taghizadeh-Hesary F, Garshasbi M, Falah M. The genetic landscape and possible therapeutics of neurofibromatosis type 2. Cancer Cell Int 2023; 23:99. [PMID: 37217995 DOI: 10.1186/s12935-023-02940-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Accepted: 05/07/2023] [Indexed: 05/24/2023] Open
Abstract
Neurofibromatosis type 2 (NF2) is a genetic condition marked by the development of multiple benign tumors in the nervous system. The most common tumors associated with NF2 are bilateral vestibular schwannoma, meningioma, and ependymoma. The clinical manifestations of NF2 depend on the site of involvement. Vestibular schwannoma can present with hearing loss, dizziness, and tinnitus, while spinal tumor leads to debilitating pain, muscle weakness, or paresthesias. Clinical diagnosis of NF2 is based on the Manchester criteria, which have been updated in the last decade. NF2 is caused by loss-of-function mutations in the NF2 gene on chromosome 22, leading the merlin protein to malfunction. Over half of NF2 patients have de novo mutations, and half of this group are mosaic. NF2 can be managed by surgery, stereotactic radiosurgery, monoclonal antibody bevacizumab, and close observation. However, the nature of multiple tumors and the necessity of multiple surgeries over the lifetime, inoperable tumors like meningiomatosis with infiltration of the sinus or in the area of the lower cranial nerves, the complications caused by the operation, the malignancies induced by radiotherapy, and inefficiency of cytotoxic chemotherapy due to the benign nature of NF-related tumors have led a march toward exploring targeted therapies. Recent advances in genetics and molecular biology have allowed identifying and targeting of underlying pathways in the pathogenesis of NF2. In this review, we explain the clinicopathological characteristics of NF2, its genetic and molecular background, and the current knowledge and challenges of implementing genetics to develop efficient therapies.
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Affiliation(s)
- Mohammad Amin Ghalavand
- ENT and Head and Neck Research Center and Department, The Five Senses Health Institute, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
- Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Alimohamad Asghari
- ENT and Head and Neck Research Center and Department, The Five Senses Health Institute, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
- Skull Base Research Center, The Five Senses Health Institute, Hazrat Rasoul Akram Hospital, Iran University of Medical Sciences, Tehran, Iran
| | - Mohammad Farhadi
- ENT and Head and Neck Research Center and Department, The Five Senses Health Institute, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Farzad Taghizadeh-Hesary
- ENT and Head and Neck Research Center and Department, The Five Senses Health Institute, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
- Radiation Oncology Department, Iran University of Medical Sciences, Tehran, Iran
| | - Masoud Garshasbi
- Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
| | - Masoumeh Falah
- ENT and Head and Neck Research Center and Department, The Five Senses Health Institute, School of Medicine, Iran University of Medical Sciences, Tehran, Iran.
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3
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Understanding the Molecular Mechanism of Vestibular Schwannoma for Hearing Preservation Surgery: Otologists’ Perspective from Bedside to Bench. Diagnostics (Basel) 2022; 12:diagnostics12051044. [PMID: 35626200 PMCID: PMC9140016 DOI: 10.3390/diagnostics12051044] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Revised: 04/19/2022] [Accepted: 04/20/2022] [Indexed: 02/04/2023] Open
Abstract
Vestibular schwannoma is a clinically benign schwannoma that arises from the vestibulocochlear nerve that causes sensorineural hearing loss. This tumor is clinically and oncologically regarded as a benign tumor as it does not metastasize or invade surrounding tissues. Despite being a benign tumor, its management is difficult and controversial due to the potential serious complications, such as irreversible sensorineural hearing loss, of current interventions. Therefore, preventing hearing loss due to the natural course of the disease and complications of surgery is a challenging issue for an otologist. Improvements have been reported recently in the treatment of vestibular schwannomas. These include advances in intraoperative monitoring systems for vestibular schwannoma surgery where the risk of hearing loss as a complication is decreased. Precise genomic analysis of the tumor would be helpful in determining the characteristics of the tumor for each patient, leading to a better hearing prognosis. These procedures are expected to help improve the treatment of vestibular schwannomas. This review summarizes recent advances in vestibular schwannoma management and treatment, especially in hearing preservation. In addition, recent advances in the understanding of the molecular mechanisms underlying vestibular schwannomas and how these advances can be applied in clinical practice are outlined and discussed, respectively. Moreover, the future directions from the bedside to the bench side are presented from the perspective of otologists.
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Gan J, Zhang Y, Wu J, Lei D, Zhang F, Zhao H, Wang L. Current Understanding of Hearing Loss in Sporadic Vestibular Schwannomas: A Systematic Review. Front Oncol 2021; 11:687201. [PMID: 34476211 PMCID: PMC8406761 DOI: 10.3389/fonc.2021.687201] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 07/21/2021] [Indexed: 11/13/2022] Open
Abstract
Objective Hearing loss is the most common initial symptom in patients with sporadic vestibular schwannomas (SVS). Hearing preservation is an important goal of both conservative and surgical therapy. However, the mechanism of SVS-associated hearing loss remains unclear. Thus, we performed this systematic review to summarize the current understanding of hearing loss in the SVS and distill a testable hypothesis to further illuminate its underlying mechanism. Methods A systematic review querying four databases (PubMed, Medline, Embase, and Web of Science) was performed to identify studies evaluating hearing loss in patients with SVS and exploring the potential mechanisms of hearing impairment. Results A total of 50 articles were eligible and included in this review. After analysis, the retrieved studies could be categorized into four types: (1) 29 studies explore the relationship between hearing loss and the growth pattern of the tumor (e.g., tumor size/volume, growth rate, tumor location, etc.); (2) ten studies investigate the potential role of cochlear dysfunction in hearing deterioration, including structural abnormality, protein elevation in perilymph, and cochlear malfunctioning; (3) two studies looked into SVS-induced impairment of auditory pathway and cortex; (4) in the rest nine studies, researchers explored the molecular mechanism underlying hearing loss in SVS, which involves molecular and genetic alterations, inflammatory response, growth factors, and other tumor-associated secretions. Conclusions Multiple factors may contribute to the hearing impairment in SVS, including the growth pattern of tumor, cochlear dysfunction, impairment of auditory pathway and cortex, genetic and molecular changes. However, our current understanding is still limited, and future studies are needed to explore this multifactorial hypothesis and dig deeper into its underlying mechanism.
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Affiliation(s)
- Jinlu Gan
- Department of Neurosurgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yanling Zhang
- Department of Obstetrics and Gynecology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jingnan Wu
- Department of Neurosurgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Deqiang Lei
- Department of Neurosurgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Fangcheng Zhang
- Department of Neurosurgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Hongyang Zhao
- Department of Neurosurgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Lei Wang
- Department of Neurosurgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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5
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Neurofibromatosis Type 2 (NF2) and the Implications for Vestibular Schwannoma and Meningioma Pathogenesis. Int J Mol Sci 2021; 22:ijms22020690. [PMID: 33445724 PMCID: PMC7828193 DOI: 10.3390/ijms22020690] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 01/06/2021] [Accepted: 01/07/2021] [Indexed: 12/14/2022] Open
Abstract
Patients diagnosed with neurofibromatosis type 2 (NF2) are extremely likely to develop meningiomas, in addition to vestibular schwannomas. Meningiomas are a common primary brain tumor; many NF2 patients suffer from multiple meningiomas. In NF2, patients have mutations in the NF2 gene, specifically with loss of function in a tumor-suppressor protein that has a number of synonymous names, including: Merlin, Neurofibromin 2, and schwannomin. Merlin is a 70 kDa protein that has 10 different isoforms. The Hippo Tumor Suppressor pathway is regulated upstream by Merlin. This pathway is critical in regulating cell proliferation and apoptosis, characteristics that are important for tumor progression. Mutations of the NF2 gene are strongly associated with NF2 diagnosis, leading to benign proliferative conditions such as vestibular schwannomas and meningiomas. Unfortunately, even though these tumors are benign, they are associated with significant morbidity and the potential for early mortality. In this review, we aim to encompass meningiomas and vestibular schwannomas as they pertain to NF2 by assessing molecular genetics, common tumor types, and tumor pathogenesis.
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6
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Ren Y, Chari DA, Vasilijic S, Welling DB, Stankovic KM. New developments in neurofibromatosis type 2 and vestibular schwannoma. Neurooncol Adv 2020; 3:vdaa153. [PMID: 33604573 PMCID: PMC7881257 DOI: 10.1093/noajnl/vdaa153] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Neurofibromatosis type 2 (NF2) is a rare autosomal dominant disorder characterized by the development of multiple nervous system tumors due to mutation in the NF2 tumor suppressor gene. The hallmark feature of the NF2 syndrome is the development of bilateral vestibular schwannomas (VS). Although there is nearly 100% penetrance by 60 years of age, some patients suffer from a severe form of the disease and develop multiple tumors at an early age, while others are asymptomatic until later in life. Management options for VS include surgery, stereotactic radiation, and observation with serial imaging; however, currently, there are no FDA-approved pharmacotherapies for NF2 or VS. Recent advancements in the molecular biology underlying NF2 have led to a better understanding of the etiology and pathogenesis of VS. These novel signaling pathways may be used to identify targeted therapies for these tumors. This review discusses the clinical features and treatment options for sporadic- and NF2-associated VS, the diagnostic and screening criteria, completed and ongoing clinical trials, quality of life metrics, and opportunities for future research.
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Affiliation(s)
- Yin Ren
- Department of Surgery, Division of Otolaryngology - Head and Neck Surgery, University of California San Diego School of Medicine, San Diego, California, USA
| | - Divya A Chari
- Department of Otolaryngology Head and Neck Surgery, Harvard Medical School, Boston, Massachusetts, USA.,Eaton-Peabody Laboratories and Department of Otolaryngology Head and Neck Surgery, Massachusetts Eye and Ear, Boston, Massachusetts, USA
| | - Sasa Vasilijic
- Department of Otolaryngology Head and Neck Surgery, Harvard Medical School, Boston, Massachusetts, USA.,Eaton-Peabody Laboratories and Department of Otolaryngology Head and Neck Surgery, Massachusetts Eye and Ear, Boston, Massachusetts, USA
| | - D Bradley Welling
- Department of Otolaryngology Head and Neck Surgery, Harvard Medical School, Boston, Massachusetts, USA.,Eaton-Peabody Laboratories and Department of Otolaryngology Head and Neck Surgery, Massachusetts Eye and Ear, Boston, Massachusetts, USA.,Speech and Hearing Bioscience and Technology Program, Harvard Medical School, Boston, Massachusetts, USA
| | - Konstantina M Stankovic
- Department of Otolaryngology Head and Neck Surgery, Harvard Medical School, Boston, Massachusetts, USA.,Eaton-Peabody Laboratories and Department of Otolaryngology Head and Neck Surgery, Massachusetts Eye and Ear, Boston, Massachusetts, USA.,Speech and Hearing Bioscience and Technology Program, Harvard Medical School, Boston, Massachusetts, USA.,Harvard Stem Cell Institute, Harvard University, Cambridge, Massachusetts, USA.,Program in Therapeutic Science, Harvard Medical School, Boston, Massachusetts, USA
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7
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Yao L, Alahmari M, Temel Y, Hovinga K. Therapy of Sporadic and NF2-Related Vestibular Schwannoma. Cancers (Basel) 2020; 12:cancers12040835. [PMID: 32244314 PMCID: PMC7226024 DOI: 10.3390/cancers12040835] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 03/29/2020] [Accepted: 03/30/2020] [Indexed: 12/16/2022] Open
Abstract
Vestibular schwannoma (VS) is a benign primary brain tumor that occurs sporadic or as part of a genetic syndrome. The most common cause is the mutation of the NF2 tumor suppressor gene that is involved in the production of the protein merlin. Merlin plays a role in cell growth and cell adhesion. In patients with NF2, the VSs arise bilaterally and coincide with other brain tumors. In sporadic VS, the tumor is typically unilateral and does not coincide in combination with other tumors. MRI is the standard imaging technique and can be used to assess the size and aspect of the tumor as well as the progression of disease. The preferred management of large VS in both VS types is surgery with or without adjuvant radiation. The management for the medium- or small-sized VS includes wait and scan, radiotherapy and/or surgery. This choice depends on the preference of the patient and institutional protocols. The outcomes of surgical and radiotherapy treatments are improving due to progress in surgical equipment/approaches, advances in radiation delivery techniques and dose optimizations protocols. The main purpose of the management of VS is preserving function as long as possible in combination with tumor control.
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Affiliation(s)
- Longping Yao
- Department of Neurosurgery, Maastricht University Medical Center, 6202 AZ Maastricht, The Netherlands; (L.Y.); (M.A.); (Y.T.)
| | - Mohammed Alahmari
- Department of Neurosurgery, Maastricht University Medical Center, 6202 AZ Maastricht, The Netherlands; (L.Y.); (M.A.); (Y.T.)
- Department of Radiology, King Fahad Hospital of Imam Abdulrahman Bin Faisal University, P.O. Box 40046, 31952 AL-Khobar, Saudi Arabia
| | - Yasin Temel
- Department of Neurosurgery, Maastricht University Medical Center, 6202 AZ Maastricht, The Netherlands; (L.Y.); (M.A.); (Y.T.)
| | - Koos Hovinga
- Department of Neurosurgery, Maastricht University Medical Center, 6202 AZ Maastricht, The Netherlands; (L.Y.); (M.A.); (Y.T.)
- Correspondence: ; Tel.: +31-43-387-50-01
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8
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Zanoletti E, Mazzoni A, Martini A, Abbritti RV, Albertini R, Alexandre E, Baro V, Bartolini S, Bernardeschi D, Bivona R, Bonali M, Borghesi I, Borsetto D, Bovo R, Breun M, Calbucci F, Carlson ML, Caruso A, Cayé-Thomasen P, Cazzador D, Champagne PO, Colangeli R, Conte G, D'Avella D, Danesi G, Deantonio L, Denaro L, Di Berardino F, Draghi R, Ebner FH, Favaretto N, Ferri G, Fioravanti A, Froelich S, Giannuzzi A, Girasoli L, Grossardt BR, Guidi M, Hagen R, Hanakita S, Hardy DG, Iglesias VC, Jefferies S, Jia H, Kalamarides M, Kanaan IN, Krengli M, Landi A, Lauda L, Lepera D, Lieber S, Lloyd SLK, Lovato A, Maccarrone F, Macfarlane R, Magnan J, Magnoni L, Marchioni D, Marinelli JP, Marioni G, Mastronardi V, Matthies C, Moffat DA, Munari S, Nardone M, Pareschi R, Pavone C, Piccirillo E, Piras G, Presutti L, Restivo G, Reznitsky M, Roca E, Russo A, Sanna M, Sartori L, Scheich M, Shehata-Dieler W, Soloperto D, Sorrentino F, Sterkers O, Taibah A, Tatagiba M, Tealdo G, Vlad D, Wu H, Zanetti D. Surgery of the lateral skull base: a 50-year endeavour. ACTA ACUST UNITED AC 2019; 39:S1-S146. [PMID: 31130732 PMCID: PMC6540636 DOI: 10.14639/0392-100x-suppl.1-39-2019] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Disregarding the widely used division of skull base into anterior and lateral, since the skull base should be conceived as a single anatomic structure, it was to our convenience to group all those approaches that run from the antero-lateral, pure lateral and postero-lateral side of the skull base as “Surgery of the lateral skull base”. “50 years of endeavour” points to the great effort which has been made over the last decades, when more and more difficult surgeries were performed by reducing morbidity. The principle of lateral skull base surgery, “remove skull base bone to approach the base itself and the adjacent sites of the endo-esocranium”, was then combined with function preservation and with tailoring surgery to the pathology. The concept that histology dictates the extent of resection, balancing the intrinsic morbidity of each approach was the object of the first section of the present report. The main surgical approaches were described in the second section and were conceived not as a step-by-step description of technique, but as the highlighthening of the surgical principles. The third section was centered on open issues related to the tumor and its treatment. The topic of vestibular schwannoma was investigated with the current debate on observation, hearing preservation surgery, hearing rehabilitation, radiotherapy and the recent efforts to detect biological markers able to predict tumor growth. Jugular foramen paragangliomas were treated in the frame of radical or partial surgery, radiotherapy, partial “tailored” surgery and observation. Surgery on meningioma was debated from the point of view of the neurosurgeon and of the otologist. Endolymphatic sac tumors and malignant tumors of the external auditory canal were also treated, as well as chordomas, chondrosarcomas and petrous bone cholesteatomas. Finally, the fourth section focused on free-choice topics which were assigned to aknowledged experts. The aim of this work was attempting to report the state of the art of the lateral skull base surgery after 50 years of hard work and, above all, to raise questions on those issues which still need an answer, as to allow progress in knowledge through sharing of various experiences. At the end of the reading, if more doubts remain rather than certainties, the aim of this work will probably be achieved.
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Affiliation(s)
- E Zanoletti
- Department of Neuroscience DNS, Otolaryngology Section, Padova University, Padova, Italy
| | - A Mazzoni
- Department of Neuroscience DNS, Otolaryngology Section, Padova University, Padova, Italy
| | - A Martini
- Department of Neuroscience DNS, Otolaryngology Section, Padova University, Padova, Italy
| | - R V Abbritti
- Department of Neurosurgery, Lariboisière Hospital, University of Paris Diderot, Paris, France
| | | | - E Alexandre
- Department of Neuroscience DNS, Otolaryngology Section, Padova University, Padova, Italy
| | - V Baro
- Academic Neurosurgery, Department of Neuroscience DNS, University of Padova Medical School, Padova, Italy
| | - S Bartolini
- Neurosurgery, Bellaria Hospital, Bologna, Italy
| | - D Bernardeschi
- AP-HP, Groupe Hôspital-Universitaire Pitié-Salpêtrière, Neuro-Sensory Surgical Department and NF2 Rare Disease Centre, Paris, France.,Sorbonne Université, Paris, France
| | - R Bivona
- ENT and Skull-Base Surgery Department, Department of Neurosciences, Ospedale Papa Giovanni XXIII, Bergamo, Italy
| | - M Bonali
- Otolaryngology-Head and Neck Surgery Department, University Hospital of Modena, Italy
| | - I Borghesi
- Neurosurgery, Maria Cecilia Hospital, Cotignola (RA), Italy
| | - D Borsetto
- Department of Neuroscience DNS, Otolaryngology Section, Padova University, Padova, Italy
| | - R Bovo
- Department of Neuroscience DNS, Otolaryngology Section, Padova University, Padova, Italy
| | - M Breun
- Department of Neurosurgery, Julius Maximilians University Hospital Würzburg, Bavaria, Germany
| | - F Calbucci
- Neurosurgery, Maria Cecilia Hospital, Cotignola (RA), Italy
| | - M L Carlson
- Department of Otolaryngology-Head and Neck Surgery, Mayo Clinic, Rochester, MN, USA.,Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, USA
| | - A Caruso
- Gruppo Otologico, Piacenza-Rome, Italy
| | - P Cayé-Thomasen
- The Department of Otorhinolaryngology, Head & Neck Surgery and Audiology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.,Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - D Cazzador
- Department of Neuroscience DNS, Otolaryngology Section, Padova University, Padova, Italy.,Department of Neuroscience DNS, Section of Human Anatomy, Padova University, Padova, Italy
| | - P-O Champagne
- Department of Neurosurgery, Lariboisière Hospital, University of Paris Diderot, Paris, France
| | - R Colangeli
- Department of Neuroscience DNS, Otolaryngology Section, Padova University, Padova, Italy
| | - G Conte
- Department of Neuroradiology, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milano, Italy
| | - D D'Avella
- Academic Neurosurgery, Department of Neuroscience DNS, University of Padova Medical School, Padova, Italy
| | - G Danesi
- ENT and Skull-Base Surgery Department, Department of Neurosciences, Ospedale Papa Giovanni XXIII, Bergamo, Italy
| | - L Deantonio
- Department of Radiation Oncology, University Hospital Maggiore della Carità, Novara, Italy.,Department of Translational Medicine, University of Piemonte Orientale, Novara, Italy
| | - L Denaro
- Academic Neurosurgery, Department of Neuroscience DNS, University of Padova Medical School, Padova, Italy
| | - F Di Berardino
- Unit of Audiology, Department of Clinical Sciences and Community Health, University of Milano, Italy.,Department of Surgery, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milano, Italy
| | - R Draghi
- Neurosurgery, Maria Cecilia Hospital, Cotignola (RA), Italy
| | - F H Ebner
- Department of Neurosurgery, Eberhard Karls University Tübingen, Germany
| | - N Favaretto
- Department of Neuroscience DNS, Otolaryngology Section, Padova University, Padova, Italy
| | - G Ferri
- Otolaryngology-Head and Neck Surgery Department, University Hospital of Modena, Italy
| | | | - S Froelich
- Department of Neurosurgery, Lariboisière Hospital, University of Paris Diderot, Paris, France
| | | | - L Girasoli
- Department of Neuroscience DNS, Otolaryngology Section, Padova University, Padova, Italy
| | - B R Grossardt
- Division of Biomedical Statistics and Informatics, Department of Health Sciences Research, Mayo Clinic, Rochester, MN, USA
| | - M Guidi
- Gruppo Otologico, Piacenza-Rome, Italy
| | - R Hagen
- Department of Otorhinolaryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery, "Julius-Maximilians" University Hospital of Würzburg, Bavaria, Germany
| | - S Hanakita
- Department of Neurosurgery, Lariboisière Hospital, University of Paris Diderot, Paris, France
| | - D G Hardy
- Department of Neurosurgery, Cambridge University Hospital, Cambridge, UK
| | - V C Iglesias
- ENT and Skull-Base Surgery Department, Department of Neurosciences, Ospedale Papa Giovanni XXIII, Bergamo, Italy
| | - S Jefferies
- Oncology Department, Cambridge University Hospital, Cambridge, UK
| | - H Jia
- Department of Otolaryngology Head and Neck Surgery, Shanghai Ninh People's Hospital, Shanghai Jiatong University School of Medicine, China
| | - M Kalamarides
- AP-HP, Groupe Hôspital-Universitaire Pitié-Salpêtrière, Neuro-Sensory Surgical Department and NF2 Rare Disease Centre, Paris, France.,Sorbonne Université, Paris, France
| | - I N Kanaan
- Department of Neurosciences, King Faisal Specialist Hospital & Research Center, Alfaisal University, College of Medicine, Riyadh, KSA
| | - M Krengli
- Department of Radiation Oncology, University Hospital Maggiore della Carità, Novara, Italy.,Department of Translational Medicine, University of Piemonte Orientale, Novara, Italy
| | - A Landi
- Academic Neurosurgery, Department of Neuroscience DNS, University of Padova Medical School, Padova, Italy
| | - L Lauda
- Gruppo Otologico, Piacenza-Rome, Italy
| | - D Lepera
- ENT & Skull-Base Department, Ospedale Nuovo di Legnano, Legnano (MI), Italy
| | - S Lieber
- Department of Neurosurgery, Eberhard Karls University Tübingen, Germany
| | - S L K Lloyd
- Department of Neuro-Otology and Skull-Base Surgery Manchester Royal Infirmary, Manchester, UK
| | - A Lovato
- Department of Neuroscience DNS, Audiology Unit, Padova University, Treviso, Italy
| | - F Maccarrone
- Otolaryngology-Head and Neck Surgery Department, University Hospital of Modena, Italy
| | - R Macfarlane
- Department of Neurosurgery, Cambridge University Hospital, Cambridge, UK
| | - J Magnan
- University Aix-Marseille, France
| | - L Magnoni
- Unit of Audiology, Department of Clinical Sciences and Community Health, University of Milano, Italy.,Department of Surgery, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milano, Italy
| | - D Marchioni
- Otolaryngology-Head and Neck Surgery Department, University Hospital of Verona, Italy
| | | | - G Marioni
- Department of Neuroscience DNS, Otolaryngology Section, Padova University, Padova, Italy
| | | | - C Matthies
- Department of Neurosurgery, Julius Maximilians University Hospital Würzburg, Bavaria, Germany
| | - D A Moffat
- Department of Neuro-otology and Skull Base Surgery, Cambridge University Hospital, Cambridge, UK
| | - S Munari
- Department of Neuroscience DNS, Otolaryngology Section, Padova University, Padova, Italy
| | - M Nardone
- ENT Department, Treviglio (BG), Italy
| | - R Pareschi
- ENT & Skull-Base Department, Ospedale Nuovo di Legnano, Legnano (MI), Italy
| | - C Pavone
- Department of Neuroscience DNS, Otolaryngology Section, Padova University, Padova, Italy
| | | | - G Piras
- Gruppo Otologico, Piacenza-Rome, Italy
| | - L Presutti
- Otolaryngology-Head and Neck Surgery Department, University Hospital of Modena, Italy
| | - G Restivo
- ENT and Skull-Base Surgery Department, Department of Neurosciences, Ospedale Papa Giovanni XXIII, Bergamo, Italy
| | - M Reznitsky
- The Department of Otorhinolaryngology, Head & Neck Surgery and Audiology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - E Roca
- Department of Neurosurgery, Lariboisière Hospital, University of Paris Diderot, Paris, France
| | - A Russo
- Gruppo Otologico, Piacenza-Rome, Italy
| | - M Sanna
- Gruppo Otologico, Piacenza-Rome, Italy
| | - L Sartori
- Academic Neurosurgery, Department of Neuroscience DNS, University of Padova Medical School, Padova, Italy
| | - M Scheich
- Department of Otorhinolaryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery, "Julius-Maximilians" University Hospital of Würzburg, Bavaria, Germany
| | - W Shehata-Dieler
- Department of Otorhinolaryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery, "Julius-Maximilians" University Hospital of Würzburg, Bavaria, Germany
| | - D Soloperto
- Otolaryngology-Head and Neck Surgery Department, University Hospital of Verona, Italy
| | - F Sorrentino
- Department of Neuroscience DNS, Otolaryngology Section, Padova University, Padova, Italy
| | - O Sterkers
- AP-HP, Groupe Hôspital-Universitaire Pitié-Salpêtrière, Neuro-Sensory Surgical Department and NF2 Rare Disease Centre, Paris, France.,Sorbonne Université, Paris, France
| | - A Taibah
- Gruppo Otologico, Piacenza-Rome, Italy
| | - M Tatagiba
- Department of Neurosurgery, Eberhard Karls University Tübingen, Germany
| | - G Tealdo
- Department of Neuroscience DNS, Otolaryngology Section, Padova University, Padova, Italy
| | - D Vlad
- Gruppo Otologico, Piacenza-Rome, Italy
| | - H Wu
- Department of Otolaryngology Head and Neck Surgery, Shanghai Ninh People's Hospital, Shanghai Jiatong University School of Medicine, China
| | - D Zanetti
- Unit of Audiology, Department of Clinical Sciences and Community Health, University of Milano, Italy.,Department of Surgery, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milano, Italy
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Sass H, Cayé-Thomasen P. Contemporary Molecular Biology of Sporadic Vestibular Schwannomas: A Systematic Review and Clinical Implications. J Int Adv Otol 2019; 14:322-329. [PMID: 30100540 DOI: 10.5152/iao.2018.4929] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
In light of missing systematic reviews in the literature, the objective of this paper is to present the contemporary knowledge on the molecular biology of vestibular schwannomas (VS), based on a systematic literature search. In addition, current and prospected medical therapy based on molecular biology is addressed. A systematic literature search was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The systematic search was performed in the Pubmed and Embase databases. The following were the words searched: acoustic neuroma/vestibular schwannoma, molecular biology, gene, and microRNA. Specific inclusion and exclusion criteria were determined prior to search. The systematic search rendered 486 articles, ultimately yielding 69 included articles, whereas 35 were from relevant references. The occurrence of at least one mutation in the merlin gene was reported to range between 54% and 76%, whereas the loss of heterozygosity (LOH) corresponding to chromosome 22 occurs in 25% to 83% of sporadic VS. Global gene expression studies indicate that a number of genes other than merlin are at play. No high-level methylation of the merlin gene has been found. Several miRNAs are deregulated in tumor tissue, among others let-7d, miR-221, and miR-21. The acquired knowledge on molecular biology has led to several clinical implementations. Lack of the tumor suppressor merlin plays a principal role in the development of VS. Existing knowledge on the molecular biology has led to the first attempts of targeted medical treatment to prevent tumor growth. Future research is likely to introduce potential imaging markers with prognostic value and new targets for medical therapy.
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Affiliation(s)
- Hjalte Sass
- Department of Otorhinolaryngology, Head and Neck Surgery and Audiology, Copenhagen University Hospital, Copenhagen, Denmark; University of Copenhagen, School of Health and Medical Sciences, Copenhagen, Denmark
| | - Per Cayé-Thomasen
- Department of Otorhinolaryngology, Head and Neck Surgery and Audiology, Copenhagen University Hospital, Copenhagen, Denmark; University of Copenhagen, School of Health and Medical Sciences, Copenhagen, Denmark
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Young ED, Ingram D, Metcalf-Doetsch W, Khan D, Al Sannaa G, Le Loarer F, Lazar AJF, Slopis J, Torres KE, Lev D, Pollock RE, McCutcheon IE. Clinicopathological variables of sporadic schwannomas of peripheral nerve in 291 patients and expression of biologically relevant markers. J Neurosurg 2017; 129:805-814. [PMID: 28885122 DOI: 10.3171/2017.2.jns153004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE While sporadic peripheral schwannomas (SPSs) are generally well treated with surgery, their biology is not well understood. Consequently, treatment options are limited. The aim of this study was to provide a comprehensive description of SPS. The authors describe clinicopathological features and treatment outcomes of patients harboring these tumors, and they assess expression of biomarkers using a clinically annotated tissue microarray. Together, these data give new insight into the biology and management of SPS. METHODS Patients presenting with a primary SPS between 1993 and 2011 (n = 291) were selected from an institutional registry to construct a clinical database. All patients underwent follow-up, and short- and long-term outcomes were assessed. Expression of relevant biomarkers was assessed using a new tissue microarray (n = 121). RESULTS SPSs were generally large (mean 5.5 cm) and frequently painful at presentation (55%). Most patients were treated with surgery (80%), the majority of whom experienced complete resolution (52%) or improvement (18%) of their symptoms. Tumors that were completely resected (85%) did not recur. Some patients experienced short-term (16%) and long-term (4%) complications postoperatively. Schwannomas expressed higher levels of platelet-derived growth factor receptor-β (2.1) than malignant peripheral nerve sheath tumors (MPNSTs) (1.5, p = 0.004) and neurofibromas (1.33, p = 0.007). Expression of human epidermal growth factor receptor-2 was greater in SPSs (0.91) than in MPNSTs (0.33, p = 0.002) and neurofibromas (0.33, p = 0.026). Epidermal growth factor receptor was expressed in far fewer SPS cells (10%) than in MPNSTs (58%, p < 0.0001) or neurofibromas (37%, p = 0.007). SPSs more frequently expressed cytoplasmic survivin (66% of tumor cells) than normal nerve (46% of cells), but SPS expressed nuclear survivin in fewer tumor cells than in MPNSTs (24% and 50%, respectively; p = 0.018). CONCLUSIONS Complete resection is curative for SPS. Left untreated, however, these tumors can cause significant morbidity, and not all patients are candidates for resection. SPSs express a pattern of biomarkers consistent with the dysregulation of the tumor suppressor merlin observed in neurofibromatosis Type 2-associated schwannomas, suggesting a shared etiology. This SPS pattern is distinct from that of other tumors of the peripheral nerve sheath.
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Affiliation(s)
- Eric D Young
- 1Department of Cancer Biology, University of Kansas Medical Center, Andover, Kansas
| | - Davis Ingram
- Departments of2Surgical Oncology.,6The Sarcoma Research Center, University of Texas MD Anderson Cancer Center, Houston, Texas
| | | | - Dilshad Khan
- 8Department of Internal Medicine, University of Toledo Medical Center, Toledo, Ohio
| | - Ghadah Al Sannaa
- 3Pathology and Laboratory Medicine.,6The Sarcoma Research Center, University of Texas MD Anderson Cancer Center, Houston, Texas
| | | | - Alexander J F Lazar
- 3Pathology and Laboratory Medicine.,6The Sarcoma Research Center, University of Texas MD Anderson Cancer Center, Houston, Texas
| | | | - Keila E Torres
- Departments of2Surgical Oncology.,6The Sarcoma Research Center, University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Dina Lev
- 10Department of Surgery, Sheba Medical Center, Israel; and
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Tumor Biology of Vestibular Schwannoma: A Review of Experimental Data on the Determinants of Tumor Genesis and Growth Characteristics. Otol Neurotol 2016; 36:1128-36. [PMID: 26049313 DOI: 10.1097/mao.0000000000000788] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
OBJECTIVE Provide an overview of the literature on vestibular schwannoma biology with special attention to tumor behavior and targeted therapy. BACKGROUND Vestibular schwannomas are benign tumors originating from the eighth cranial nerve and arise due to inactivation of the NF2 gene and its product merlin. Unraveling the biology of these tumors helps to clarify their growth pattern and is essential in identifying therapeutic targets. METHODS PubMed search for English-language articles on vestibular schwannoma biology from 1994 to 2014. RESULTS Activation of merlin and its role in cell signaling seem as key aspects of vestibular schwannoma biology. Merlin is regulated by proteins such as CD44, Rac, and myosin phosphatase-targeting subunit 1. The tumor-suppressive functions of merlin are related to receptor tyrosine kinases, such as the platelet-derived growth factor receptor and vascular endothelial growth factor receptor. Merlin mediates the Hippo pathway and acts within the nucleus by binding E3 ubiquiting ligase CRL4. Angiogenesis is an important mechanism responsible for the progression of these tumors and is affected by processes such as hypoxia and inflammation. Inhibiting angiogenesis by targeting vascular endothelial growth factor receptor seems to be the most successful pharmacologic strategy, but additional therapeutic options are emerging. CONCLUSION Over the years, the knowledge on vestibular schwannoma biology has significantly increased. Future research should focus on identifying new therapeutic targets by investigating vestibular schwannoma (epi)genetics, merlin function, and tumor behavior. Besides identifying novel targets, testing new combinations of existing treatment strategies can further improve vestibular schwannoma therapy.
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12
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13
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Sporadic vestibular schwannomas associated with good hearing secrete higher levels of fibroblast growth factor 2 than those associated with poor hearing irrespective of tumor size. Otol Neurotol 2013; 34:748-54. [PMID: 23512073 DOI: 10.1097/mao.0b013e31828048ec] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
HYPOTHESIS We hypothesize that the severity of hearing loss (HL) associated with sporadic vestibular schwannomas (VS) is correlated with tumor secretion of proteins with ototoxic or otoprotective potential. BACKGROUND Because the recognition that HL associated with VS is not solely due to compression of the auditory nerve, elucidating the mechanism by which VS cause HL has been an important task. We previously showed that VS stratified by hearing have differential gene expression. We now focus on identifying differentially expressed proteins in tumor secretions. METHODS Fresh surgical specimens of VS were incubated in sterile PBS at 37°C to collect secretions. The specimens were divided into a group associated with good hearing (GH, word recognition ≥ 70% and pure-tone average ≤ 30 dB, n = 11) or poor hearing (PH, n = 10). The groups were compared using a customized cytokine array. Statistically significant results were verified with an enzyme-linked immunosorbent assay on a different set of secretions (n = 8 for GH and n = 10 for PH group). RESULTS Of the 37 molecules we studied, 9 were significantly expressed in secretions from VS compared with secretions from control nerves. Secretion of fibroblast growth factor 2 (FGF2) was 3.5-fold higher in VS associated with GH versus PH based on cytokine array analysis (p = 0.02), which was validated with enzyme-linked immunosorbent assay. CONCLUSION This study highlights FGF2, a mitogen known to protect the auditory nerve, as a potential tumor-secreted mediator of hearing protection in VS. If FGF2's significant role in hearing protection in patients with VS is validated, then FGF2 could be used as a biomarker for HL in VS, and therapeutic targeting of the FGF2 signaling pathway may reduce HL due to VS.
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Microsurgery versus stereotactic radiation for small vestibular schwannomas: a meta-analysis of patients with more than 5 years' follow-up. Otol Neurotol 2013; 33:1611-20. [PMID: 22996165 DOI: 10.1097/mao.0b013e31826dbd02] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To compare the long-term outcome of hearing and tumor outcome of small vestibular schwannomas treated with stereotactic radiation and microsurgery. DATA SOURCES A thorough search for English-language publications and "in process" articles dating from 1948 to December 2011 was conducted using Ovid MEDLINE. STUDY SELECTION The principal criteria were patients having had microsurgery or radiation therapy as their sole treatment, with a follow-up of at least 5 years, and a useful hearing level at diagnosis. DATA EXTRACTION Sixteen studies met our criteria. Hearing preservation outcome (worse or preserved) and tumor outcome (failure, control) data, as well as all other significant observations, were collected from the articles. Stereotactic radiation was the only radiation therapy analyzed. DATA SYNTHESIS The Pearson χ test was our primary statistical analysis. CONCLUSION Stereotactic radiation showed significantly better long-term hearing preservation outcome rates than microsurgery (p < 0.001). However, long-term tumor outcome was not significantly different in stereotactic radiation as compared with microsurgery (p = 0.122). Although stereotactic radiation demonstrates a more favorable long-term hearing preservation outcome as compared with microsurgery, additional studies are required to provide the medical field with a better understanding of vestibular schwannoma treatment.
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Abstract
A comprehensive discussion of neurofibromatosis 2 (NF2) is presented, including clinical characteristics, symptoms, diagnosis, tumor types, prevalence and incidence, genetic testing, imaging, treatment options, and follow-up management of NF2.
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Affiliation(s)
- Michael Hoa
- House Clinic, House Research Institute, 2100 West 3rd Street, Suite 111, Los Angeles, CA 90057, USA
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Celis-Aguilar E, Lassaletta L, Torres-Martín M, Rodrigues FY, Nistal M, Castresana JS, Gavilan J, Rey JA. The molecular biology of vestibular schwannomas and its association with hearing loss: a review. GENETICS RESEARCH INTERNATIONAL 2012; 2012:856157. [PMID: 22567403 PMCID: PMC3335540 DOI: 10.1155/2012/856157] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2011] [Revised: 10/08/2011] [Accepted: 11/03/2011] [Indexed: 01/16/2023]
Abstract
Hearing loss is the most common symptom in patients with vestibular schwannoma (VS). In the past, compressive mechanisms caused by the tumoral mass and its growth have been regarded as the most likely causes of the hearing loss associated with VS. Interestingly, new evidence proposes molecular mechanisms as an explanation for such hearing loss. Among the molecular mechanisms proposed are methylation of TP73, negative expression of cyclin D1, expression of B7-H1, increased expression of the platelet-derived growth factor A, underexpression of PEX5L, RAD54B, and PSMAL, and overexpression of CEA. Many molecular mechanisms are involved in vestibular schwannoma development; we review some of these mechanisms with special emphasis on hearing loss associated with vestibular schwannoma.
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Affiliation(s)
- Erika Celis-Aguilar
- Instituto Nacional de Neurología y Neurocirugía Manuel Velasco Suarez, 14269 Ciudad de México, DF, Mexico
| | - Luis Lassaletta
- Department of Otolaryngology, “La Paz” University Hospital, 28046 Madrid, Spain
| | - Miguel Torres-Martín
- Unidad de Investigación, Laboratorio Oncogenetica Molecular, “La Paz” University Hospital, 28046 Madrid, Spain
| | - F. Yuri Rodrigues
- Department of Pathology, “La Paz” University Hospital, 28046 Madrid, Spain
| | - Manuel Nistal
- Department of Pathology, “La Paz” University Hospital, 28046 Madrid, Spain
| | - Javier S. Castresana
- Brain Tumor Biology Unit, CIFA, University of Navarra School of Sciences, 31009 Pamplona, Spain
| | - Javier Gavilan
- Department of Otolaryngology, “La Paz” University Hospital, 28046 Madrid, Spain
| | - Juan A. Rey
- Department of Pathology, “La Paz” University Hospital, 28046 Madrid, Spain
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19
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Lee JD, Kwon TJ, Kim UK, Lee WS. Genetic and epigenetic alterations of the NF2 gene in sporadic vestibular schwannomas. PLoS One 2012; 7:e30418. [PMID: 22295085 PMCID: PMC3266248 DOI: 10.1371/journal.pone.0030418] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2011] [Accepted: 12/15/2011] [Indexed: 12/11/2022] Open
Abstract
Background Mutations in the neurofibromatosis type 2 (NF2) tumor-suppressor gene have been identified in not only NF2-related tumors but also sporadic vestibular schwannomas (VS). This study investigated the genetic and epigenetic alterations in tumors and blood from 30 Korean patients with sporadic VS and correlated these alterations with tumor behavior. Methodology/Principal Findings NF2 gene mutations were detected using PCR and direct DNA sequencing and three highly polymorphic microsatellite DNA markers were used to assess the loss of heterozygosity (LOH) from chromosome 22. Aberrant hypermethylation of the CpG island of the NF2 gene was also analyzed. The tumor size, the clinical growth index, and the proliferative activity assessed using the Ki-67 labeling index were evaluated. We found 18 mutations in 16 cases of 30 schwannomas (53%). The mutations included eight frameshift mutations, seven nonsense mutations, one in-frame deletion, one splicing donor site, and one missense mutation. Nine patients (30%) showed allelic loss. No patient had aberrant hypermethylation of the NF2 gene and correlation between NF2 genetic alterations and tumor behavior was not observed in this study. Conclusions/Significance The molecular genetic changes in sporadic VS identified here included mutations and allelic loss, but no aberrant hypermethylation of the NF2 gene was detected. In addition, no clear genotype/phenotype correlation was identified. Therefore, it is likely that other factors contribute to tumor formation and growth.
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Affiliation(s)
- Jong Dae Lee
- Department of Otorhinolaryngology-Head and Neck Surgery, Soonchunhyang University College of Medicine, Bucheon, Korea
| | - Tae Jun Kwon
- Department of Biology, College of Natural Sciences, Kyungpook National University, Daegu, Korea
| | - Un-Kyung Kim
- Department of Biology, College of Natural Sciences, Kyungpook National University, Daegu, Korea
- * E-mail:
| | - Won-Sang Lee
- Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, Korea
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21
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Fong B, Barkhoudarian G, Pezeshkian P, Parsa AT, Gopen Q, Yang I. The molecular biology and novel treatments of vestibular schwannomas. J Neurosurg 2011; 115:906-14. [PMID: 21800959 DOI: 10.3171/2011.6.jns11131] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Vestibular schwannomas are histopathologically benign tumors arising from the Schwann cell sheath surrounding the vestibular branch of cranial nerve VIII and are related to the NF2 gene and its product merlin. Merlin acts as a tumor suppressor and as a mediator of contact inhibition. Thus, deficiencies in both NF2 genes lead to vestibular schwannoma development. Recently, there have been major advances in our knowledge of the molecular biology of vestibular schwannomas as well as the development of novel therapies for its treatment. In this article the authors comprehensively review the recent advances in the molecular biology and characterization of vestibular schwannomas as well as the development of modern treatments for vestibular schwannoma. For instance, merlin is involved with a number of receptors including the CD44 receptor, EGFR, and signaling pathways, such as the Ras/raf pathway and the canonical Wnt pathway. Recently, merlin was also shown to interact in the nucleus with E3 ubiquitin ligase CRL4(DCAF1). A greater understanding of the molecular mechanisms behind vestibular schwannoma tumorigenesis has begun to yield novel therapies. Some authors have shown that Avastin induces regression of progressive schwannomas by over 40% and improves hearing. An inhibitor of VEGF synthesis, PTC299, is currently in Phase II trials as a potential agent to treat vestibular schwannoma. Furthermore, in vitro studies have shown that trastuzumab (an ERBB2 inhibitor) reduces vestibular schwannoma cell proliferation. With further research it may be possible to significantly reduce morbidity and mortality rates by decreasing tumor burden, tumor volume, hearing loss, and cranial nerve deficits seen in vestibular schwannomas.
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Affiliation(s)
- Brendan Fong
- Department of Neurological Surgery, University of California, Los Angeles, CA 90095-1761, USA
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22
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Almeida LOD, Custódio AC, Santos MJD, Almeida JRW, Clara CA, Pinto GR, Rey JA, Casartelli C. The A61G EGF polymorphism is associated with development of extraaxial nervous system tumors but not with overall survival. ACTA ACUST UNITED AC 2010; 198:15-21. [PMID: 20303009 DOI: 10.1016/j.cancergencyto.2009.11.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2009] [Revised: 10/24/2009] [Accepted: 11/19/2009] [Indexed: 11/18/2022]
Abstract
Epidermal growth factor can activate several signaling pathways, leading to proliferation, differentiation, and tumorigenesis of epithelial tissues by binding with its receptor. The EGF protein is involved in nervous system development, and polymorphisms in the EGF gene on chromosome band 4q25 are associated with brain cancers. The purpose of this study was to investigate the association between the single-nucleotide polymorphism of EGF+61G/A and extraaxial brain tumors in a population of the southeast of Brazil. We analyzed the genotype distribution of this polymorphism in 90 patients and 100 healthy subjects, using the polymerase chain reaction-restriction fragment length polymorphism technique. Comparison of genotype distribution revealed a significant difference between patients and control subjects (P < 0.001). The variant genotypes of A/G and G/G were associated with a significant increase of the risk of tumor development, compared with the homozygote A/A (P < 0.0001). When the analyses were stratified, we observed that the genotype G/G was more frequent in female patients (P=0.021). The same genotype was observed more frequently in patients with low-grade tumors (P=0.001). Overall survival rates did not show statistically significant differences. Our data suggest that the EGF A61G polymorphism can be associated with susceptibility to development of these tumors.
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Affiliation(s)
- Luciana Oliveira de Almeida
- Oncogenetics Laboratory, Department of Medical Genetics, Ribeirão Preto Medical School, University of São Paulo, 14049-900, Ribeirão Preto, SP, Brazil.
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Sughrue ME, Yeung AH, Rutkowski MJ, Cheung SW, Parsa AT. Molecular biology of familial and sporadic vestibular schwannomas: implications for novel therapeutics. J Neurosurg 2009; 114:359-66. [PMID: 19943731 DOI: 10.3171/2009.10.jns091135] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Vestibular schwannomas (VSs) are benign tumors arising from the sheath of cranial nerve VIII. The pathogenesis underlying most familial and sporadic VSs has been linked to a mutation in a single gene, the neurofibromin 2 (NF2) gene located on chromosome 22, band q11-13.1. In this review, the authors summarized what is known about the epidemiology of NF2 mutations and patients with VSs. The authors also discuss the function of the NF2 gene product, merlin, and describe the known and hypothetical effects of genetic mutations that lead to merlin dysfunction on a broad variety of cellular and histological end points. A better understanding of the molecular pathobiology of VSs may lead to novel therapeutics to augment current modalities of treatment while minimizing morbidity.
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Affiliation(s)
- Michael E Sughrue
- Department of Otolaryngology-Head and Neck Surgery, University of California at San Francisco, 94143-0350, USA
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Abstract
Recent advances in molecular biology have led to a better understanding of the etiology of vestibular schwannomas. The underlying purpose of vestibular schwannoma research is the development of new treatment options; however, such options have not yet been established. A fundamental understanding of the underlying molecular events leading to tumor formation began when mutations in the neurofibromatosis type 2 (NF2) tumor suppressor gene were identified in vestibular schwannomas. The clinical characteristics of vestibular schwannomas and neurofibromatosis type 2 (NF2) syndromes have both been related to alterations in the NF2 gene. Genetic screening for NF2 is now available. When utilized with clinical screening, such as magnetic resonance imaging (MRI), conventional audiometry, and auditory brainstem response (ABR), the early detection of NF2 can be made, which consequently makes a significant difference in the ability to successfully treat vestibular schwannomas. Additionally, the signaling pathways affected by merlin, the product of the NF2 gene, are becoming better understood. Nf2-transgenic and knockout mice as well as vestibular schwannoma xenograft models are now ready for novel therapeutic testing. Hopefully, better treatment options will be forthcoming soon.
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Affiliation(s)
- Long-Sheng Chang
- Department of Pediatrics, The Ohio State University College of Medicine, Center for Childhood Cancer Research Institute at National Childen's Hospital, Columbus, OH, USA
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Asthagiri AR, Helm GA, Sheehan JP. Current concepts in management of meningiomas and schwannomas. Neurol Clin 2008; 25:1209-30, xi. [PMID: 17964032 DOI: 10.1016/j.ncl.2007.07.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Meningiomas and schwannomas are the two most common extra-axial intracranial tumors in adults. Since their initial discovery, these often-benign lesions have shared a parallel metamorphosis in their management. The goal of this article is to provide a review of the current literature surrounding the mainstays of therapy for these lesions.
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Welling DB, Packer MD, Chang LS. Molecular studies of vestibular schwannomas: a review. Curr Opin Otolaryngol Head Neck Surg 2007; 15:341-6. [PMID: 17823551 DOI: 10.1097/moo.0b013e3282b97310] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW To summarize advances in understanding the molecular biology of vestibular schwannomas over the past year. RECENT FINDINGS The role of the neurofibromatosis type 2 protein, denoted as merlin or schwannomin, in embryonic development, cellular adherence, and in cell proliferation has become better elucidated in the past year. Likewise, the role of merlin in Schwann cell-axon interaction has been studied. Additionally, two comprehensive analyses of the spectrum of human neurofibromatosis type 2 mutations have been compiled which make up a valuable resource in understanding critical regions of the neurofibromatosis type 2 gene. Neurofibromatosis type 2 screening guidelines for young patients with solitary vestibular schwannomas have been published. The role of electromagnetic radiation via cellular and portable telephones as a predisposing factor to vestibular schwannoma formation has also been the topic of several studies. Based on increased knowledge of the pathways in which merlin functions and the available transgenic and xenograft mouse models, preliminary data regarding directed pharmacotherapy are also summarized. SUMMARY With increased knowledge of the pathologic mechanisms and interacting proteins associated with merlin, the research community is poised to begin trials of targeted interventions in vitro and in the current mouse models.
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Affiliation(s)
- D Bradley Welling
- Department of Otolaryngology, The Ohio State University College of Medicine and Children's Hospital, Columbus, Ohio 43210, USA.
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27
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Ahronowitz I, Xin W, Kiely R, Sims K, MacCollin M, Nunes FP. Mutational spectrum of the NF2 gene: a meta-analysis of 12 years of research and diagnostic laboratory findings. Hum Mutat 2007; 28:1-12. [PMID: 16983642 DOI: 10.1002/humu.20393] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The NF2 tumor suppressor gene on chromosome 22 is a member of the protein 4.1 family of cytoskeletal elements. A number of single- and multiple-tumor phenotypes have been linked to alterations of NF2 since its characterization in 1993. We present a meta-analysis of 967 constitutional and somatic NF2 alterations from 93 published reports, along with 59 additional unpublished events identified in our laboratory and 115 alterations identified in clinical samples submitted to the Massachusetts General Hospital (MGH) Neurogenetics DNA Diagnostic Laboratory. In total, these sources defined 1,070 small genetic changes detected primarily by exon scanning, 42 intragenic changes of one whole exon or larger, and 29 whole gene deletions and gross chromosomal rearrangements. Constitutional single-exon events (N=422) were significantly more likely to be nonsense or splice site changes than somatic events (N=533), which favored frameshift changes (chi(2) test; P<0.001). Somatic events also differed markedly between tumors of different pathology, most significantly in the tendency of somatic events in meningiomas to lie within the 5' FERM domain of the transcript (Fisher's exact test; P<0.01 in comparison to schwannomas) with a complete absence of mutations in exons 14 and 15. There was no statistically significant difference in mutation type or exon distribution between published constitutional events and those found by the clinical laboratory. Less than 10% of all published and unpublished small alterations are nontruncating (N=63) and these changes are clustered in exons 2 and 3, suggesting that this region may be especially crucial to tumor suppressor activity in the protein.
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Affiliation(s)
- Iris Ahronowitz
- Molecular Neurofibromatosis Laboratory, Massachusetts General Hospital, Charlestown, Massachusetts 02129, USA
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Neff BA, Welling DB, Akhmametyeva E, Chang LS. The molecular biology of vestibular schwannomas: dissecting the pathogenic process at the molecular level. Otol Neurotol 2007; 27:197-208. [PMID: 16436990 DOI: 10.1097/01.mao.0000180484.24242.54] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE The goal of this article was to review concisely what is currently known about the tumorigenesis of vestibular schwannomas. BACKGROUND Recent advances in molecular biology have led to a better understanding of the cause of vestibular schwannomas. Mutations in the neurofibromatosis type 2 tumor suppressor gene (NF2) have been identified in these tumors. In addition, the interactions of merlin, the protein product of the NF2 gene, and other cellular proteins are beginning to give us a better idea of NF2 function and the pathogenesis of vestibular schwannomas. METHODS Review of the relevant basic science studies at our institution as well as the basic science and clinical literature. RESULTS The clinical characteristics of vestibular schwannomas and neurofibromatosis type 2 syndromes are reviewed and related to alterations in the NF2 gene. Studies demonstrating our current understanding of tumor developmental pathways are highlighted. In addition, methods of clinical and genetic screening for neurofibromatosis type 2 disease are outlined. Avenues for the development of potential future research and therapies are discussed. CONCLUSION Great strides have been made to identify why vestibular schwannomas develop at the molecular level. Continued research is needed to find targeted therapies with which to treat these tumors.
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Affiliation(s)
- Brian A Neff
- Department of Otolaryngology, The Ohio State University College of Medicine and Children's Hospital, Columbus, Ohio, USA
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Hansen MR, Roehm PC, Chatterjee P, Green SH. Constitutive neuregulin-1/ErbB signaling contributes to human vestibular schwannoma proliferation. Glia 2006; 53:593-600. [PMID: 16432850 DOI: 10.1002/glia.20316] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Vestibular schwannomas (VSs) are benign tumors that arise from the Schwann cells (SCs) lining the vestibular nerve. VS cells survive and proliferate far from neurons and axonally derived growth factors. We have previously shown that VSs produce the glial growth factor, neuregulin-1 (NRG1), and its receptors, ErbB2 and ErbB3. In the present work, we explore the contribution of constitutive NRG1:ErbB signaling to human VS cell proliferation. We confirm that human VSs, which express markers of immature and denervated SCs, also express endogenous NRG1 and activated ErbB2. We find that a blocking anti-NRG1 antibody and trastuzumab (Herceptin, HCN), a humanized anti-ErbB2 inhibitory monoclonal antibody, effectively inhibit NRG1 induced SC proliferation. Treatment of primary VS cultures with anti-NRG1 or HCN reduces cell proliferation in the absence of exogenous NRG1. Furthermore, conditioned medium from VS cell cultures contains NRG1 and stimulates SC proliferation in SC cultures, an effect that is inhibited by anti-NRG1 and HCN. These data suggest an autocrine pathway of VS growth stimulation involving NRG and ErbB receptors. Inhibition of constitutive NRG:ErbB signaling reduces VS cell proliferation in vitro and may have therapeutic potential for patients with VSs.
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MESH Headings
- Animals
- Animals, Newborn
- Antibodies/pharmacology
- Autocrine Communication/drug effects
- Autocrine Communication/physiology
- Biomarkers/metabolism
- Cell Differentiation/drug effects
- Cell Differentiation/physiology
- Cell Division/drug effects
- Cell Division/physiology
- Cell Proliferation/drug effects
- Cell Transformation, Neoplastic/genetics
- Cell Transformation, Neoplastic/metabolism
- Cells, Cultured
- Culture Media, Conditioned/pharmacology
- Down-Regulation/drug effects
- Down-Regulation/physiology
- Gene Expression Regulation, Neoplastic/physiology
- Glycoproteins/metabolism
- Humans
- Neuregulin-1/antagonists & inhibitors
- Neuregulin-1/genetics
- Neuregulin-1/metabolism
- Neuroma, Acoustic/genetics
- Neuroma, Acoustic/metabolism
- Neuroma, Acoustic/pathology
- Oncogene Proteins v-erbB/genetics
- Oncogene Proteins v-erbB/metabolism
- Rats
- Receptor, ErbB-2
- Schwann Cells/drug effects
- Schwann Cells/metabolism
- Signal Transduction/physiology
- Stem Cells/drug effects
- Stem Cells/metabolism
- Vestibular Nerve/metabolism
- Vestibular Nerve/pathology
- Vestibular Nerve/physiopathology
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Affiliation(s)
- Marlan R Hansen
- Department of Otolaryngology-Head and Neck Surgery, University of Iowa Hospitals and Clinics, Iowa City, 52242, USA.
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Ruttledge MH, Rouleau GA. Role of the neurofibromatosis Type 2 gene in the development of tumors of the nervous system. Neurosurg Focus 2005; 19:E6. [PMID: 16398470 DOI: 10.3171/foc.2005.19.5.7] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Germ line and somatic mutations in the neurofibromatosis Type 2 (NF2) tumor suppressor gene predispose individuals to tumors of the nervous system, including schwannomas and meningiomas. Since identification of the NF2 gene more than a decade ago, a large body of information has been collected on the nature and consequences of these alterations in patients with NF2 and in individuals in whom sporadic tumors associated with NF2 develop. The catalog of mutations identified thus far has facilitated extensive genetic analysis, including studies of patients with mosaicism and phenotype–genotype correlations, and has also led to experiments that have begun to unravel the molecular biology of the NF2 gene and its role in tumorigenesis. The authors describe some of the most significant findings in NF2 genetics and biology over the last decade.
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Affiliation(s)
- Martin H Ruttledge
- Department of Neurology, Kings College Hospital, London, United Kingdom.
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Neff BA, Welling DB. Current Concepts in the Evaluation and Treatment of Neurofibromatosis Type II. Otolaryngol Clin North Am 2005; 38:671-84, ix. [PMID: 16005725 DOI: 10.1016/j.otc.2005.01.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
This article presents the current diagnostic and treatment options for the hereditary disease neurofibromatosis type II, reviews clinical presentation and diagnosis, highlights indications for and methods of clinical and genetic screening, discusses treatment approaches for surgery and stereotactic radiation, and summarizes potential future therapeutic avenues.
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Affiliation(s)
- Brian A Neff
- Department of Otolaryngology, Mayo Clinic, Rochester, MN, USA
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Hansen MR, Linthicum FH. Expression of Neuregulin and Activation of erbB Receptors in Vestibular Schwannomas: Possible Autocrine Loop Stimulation. Otol Neurotol 2004; 25:155-9. [PMID: 15021776 DOI: 10.1097/00129492-200403000-00013] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
HYPOTHESIS We sought to determine whether vestibular schwannomas are capable of producing and responding to the glial growth factor neuregulin. BACKGROUND Neuregulin is a neuronally derived trophic factor that interacts with erbB2 and erbB3 receptors on Schwann cells and is required for normal Schwann cell proliferation, survival, and development. Vestibular schwannomas grow several millimeters or even centimeters away from adjacent axons, suggesting that vestibular schwannomas do not depend critically on axons for their proliferation or survival. This raises the possibility that vestibular schwannomas themselves produce and respond to trophic factors in an autocrine fashion. METHODS Pathologic specimens from eight patients undergoing microsurgical removal of vestibular schwannomas and one patient undergoing vestibular nerve section were immunostained with anti-neuregulin, anti-erbB2, anti-erbB3, and anti-phosphorylated-erbB2 antibodies. Three patients had received previous gamma knife radiation therapy and two patients had neurofibromatosis Type 2. RESULTS The Scarpa ganglion neurons express neuregulin, and normal vestibular Schwann cells express erbB2 and erbB3. Vestibular schwannomas from all eight patients demonstrated neuregulin, erbB2, and erbB3 immunoreactivity. In addition, all vestibular schwannomas demonstrated immunoreactivity to anti-phosphorylated-erbB2 antibody that only recognizes erbB2 when it is phosphorylated, or activated. CONCLUSION These results demonstrate that vestibular schwannomas express neuregulin and its receptors, erbB2 and erbB3. Because erbB2 exists in an activated state, as evidenced by phosphorylated-erbB2 immunoreactivity, it likely responds to the locally produced neuregulin. This suggests the possibility that vestibular schwannomas produce and respond to neuregulin in an autocrine fashion.
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Affiliation(s)
- Marlan R Hansen
- Department of Otolaryngology-Head and Neck Surgery, University of Iowa Hospitals and Clinics, Iowa City, Iowa 52242, USA.
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Welling DB, Lasak JM, Akhmametyeva E, Ghaheri B, Chang LS. cDNA microarray analysis of vestibular schwannomas. Otol Neurotol 2002; 23:736-48. [PMID: 12218628 DOI: 10.1097/00129492-200209000-00022] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Vestibular schwannomas are known to harbor mutations in the neurofibromatosis type 2 tumor suppressor gene, but the mechanism of the neurofibromatosis type 2 tumor suppressor gene action is not well understood. Identification of genes differentially expressed in normal and diseased tissues through the use of a large-scale, cDNA microarray approach may lead to increased understanding of pathways that lead to tumor formation. OBJECTIVE The objectives of this study were to evaluate the gene expression profiles in vestibular schwannomas in comparison with normal vestibular nerve tissues and to identify pathways that may be altered in schwannomas. METHODS Total RNA was extracted from one normal vestibular nerve and seven vestibular schwannomas. The normal vestibular nerve was from one of the seven patients with small vestibular schwannomas. Radiolabeled cDNA was synthesized and hybridized to cDNA microarray filters that contained 25,920 known genes or expressed sequence tags. Expression profiles were imaged and analyzed. Selected genes that showed three-fold or greater difference in the intensity between the normal nerve and the schwannomas were further examined by real-time polymerase chain reaction and by immunohistochemical staining. RESULTS Forty-two genes (0.2%) were upregulated 3-fold or more in at least 5 of the 7 tumors when the filter images were compared with a normal adjacent vestibular nerve. Among them, osteonectin, an angiogenesis mediator, and RhoB GTPase, which is important in cell signaling, were significantly upregulated in 5 of 7 tumors. Among genes that were downregulated, an apoptosis-related LUCA-15 gene was highly underexpressed in 6 of 7 schwannomas when compared with the normal nerve. Also, ezrin, a relative of the NF2 protein, was significantly downregulated in 5 of 7 tumors. Real-time PCR and immunohistochemistry data support the cDNA microarray findings. CONCLUSION Our cDNA microarray analysis of schwannomas suggested several interesting and potentially important tumorigenesis pathways associated with vestibular schwannoma formation. Further in vivo study is necessary to define the roles of these identified genes and their potential relationships with the neurofibromatosis type 2 tumor suppressor gene.
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Affiliation(s)
- D Bradley Welling
- Department of Otolaryngology, Ohio State University College of Medicine, Ohio, USA.
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Fernandez-Valle C, Tang Y, Ricard J, Rodenas-Ruano A, Taylor A, Hackler E, Biggerstaff J, Iacovelli J. Paxillin binds schwannomin and regulates its density-dependent localization and effect on cell morphology. Nat Genet 2002; 31:354-62. [PMID: 12118253 DOI: 10.1038/ng930] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Neurofibromatosis type 2 is an autosomal dominant disorder characterized by tumors, predominantly schwannomas, in the nervous system. It is caused by mutations in the gene NF2, encoding the growth regulator schwannomin (also known as merlin). Mutations occur throughout the 17-exon gene, with most resulting in protein truncation and undetectable amounts of schwannomin protein. Pathogenic mutations that result in production of defective schwannomin include in-frame deletions of exon 2 and three independent missense mutations within this same exon. Mice with conditional deletion of exon 2 in Schwann cells develop schwannomas, which confirms the crucial nature of exon 2 for growth control. Here we report that the molecular adaptor paxillin binds directly to schwannomin at residues 50-70, which are encoded by exon 2. This interaction mediates the membrane localization of schwannomin to the plasma membrane, where it associates with beta 1 integrin and erbB2. It defines a pathogenic mechanism for the development of NF2 in humans with mutations in exon 2 of NF2.
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Affiliation(s)
- Cristina Fernandez-Valle
- Department of Molecular Biology and Microbiology, University of Central Florida, Orlando, Florida 32826, USA.
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35
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Scoles DR, Chen M, Pulst SM. Effects of Nf2 missense mutations on schwannomin interactions. Biochem Biophys Res Commun 2002; 290:366-74. [PMID: 11779178 DOI: 10.1006/bbrc.2001.6178] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Most benign brain tumors are associated with loss of the Nf2 gene tumor suppressor product schwannomin/merlin. Interactions between schwannomin fragments have given rise to hypotheses of in vivo schwannomin folding and dimerization. Previously, we showed that schwannomin with missense mutations L360P, L535P, and Q538P alters interaction with betaII-spectrin and Hrs. Using yeast two-hybrid tests of interaction, we now show the effects of 11 Nf2 missense mutations on schwannomin self-interaction as well as schwannomin interaction with Hrs isoforms 1 and 2, betaII-spectrin, and p110. Missense mutations L46R and K364I significantly decreased affinity of schwannomin for binding all interacting proteins. The schwannomin L46R mutation may result in a complex conformational change that alters folding and denies betaII-spectrin access to an intact binding site in the C-terminal half of schwannomin. We show that unique inter- and intramolecular interactions occur for schwannomin isoform 2, suggesting that this schwannomin isoform has unique functional properties compared to schwannomin isoform 1.
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Affiliation(s)
- Daniel R Scoles
- Division of Neurology, Cedars-Sinai Medical Center, 1145E Medical Tower, 8631 West 3rd Street, Los Angeles, CA 90048, USA.
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Chang LS, Akhmametyeva EM, Wu Y, Zhu L, Welling DB. Multiple transcription initiation sites, alternative splicing, and differential polyadenylation contribute to the complexity of human neurofibromatosis 2 transcripts. Genomics 2002; 79:63-76. [PMID: 11827459 DOI: 10.1006/geno.2001.6672] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Northern blot analysis has shown that the human neurofibromatosis type 2 (NF2) cDNA hybridizes to multiple RNA species. To examine whether these hybridizing RNA species represent NF2 transcripts, we cloned the complete NF2 cDNA by a combination of techniques: 5' and 3' rapid amplification of cDNA ends, RT-PCR, and searching and sequencing the NF2-related cDNA clones from the IMAGE consortium. We showed that human NF2 transcripts initiate at multiple positions. Analogous to those reported previously, NF2 transcripts undergo alternative splicing in the coding exons. We isolated eight alternatively spliced NF2 cDNA isoforms, including one that contains a new exon termed exon 2', which potentially could encode proteins of different sizes. We assembled the overlapping cDNA fragments, and the longest NF2 cDNA, containing all 17 exons, consists of 6067 nucleotides, which is consistent with the size of the major RNA species hybridized to the NF2 probe. The cDNA has a 425-nucleotide 5' untranslated region upstream from the ATG start codon, and a long 3' untranslated region of 3869 nucleotides. We also isolated two shorter NF2 cDNAs that were terminated by different polyadenylation signal sequences, which indicates that differential usage of multiple polyadenylation sites also contributes to the complexity of human NF2 transcripts. By reference to the transcription initiation site mapped, we analyzed the 5' flanking sequence of the human NF2 gene. Transient transfection analysis in human 293 kidney, SK-N-AS neuroblastoma, and NT2/D1 teratocarcinoma cells with NF2 promoter-luciferase chimeric constructs revealed a core promoter region extending 400 base pairs from the major transcription initiation site. Although multiple regions are required for full promoter activity, a site-directed mutagenesis experiment identified a GC-rich sequence (position -58 to -46), which could be bound by transcription factor Sp1, as a positive cis-acting regulatory element. Cotransfection studies in Drosophila melanogaster SL2 cells showed that Sp1 could activate the NF2 promoter through the GC-rich sequence.
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Affiliation(s)
- Long-Sheng Chang
- Children's Research Institute, Children's Hospital, The Ohio State University College of Medicine and Public Health, Columbus, OH 43205, USA.
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Kaneko T, Yamashima T, Tohma Y, Nomura M, Imajoh-Ohmi S, Saido TC, Nakao M, Saya H, Yamamoto H, Yamashita J. Calpain-dependent proteolysis of merlin occurs by oxidative stress in meningiomas: a novel hypothesis of tumorigenesis. Cancer 2001; 92:2662-72. [PMID: 11745202 DOI: 10.1002/1097-0142(20011115)92:10<2662::aid-cncr1620>3.0.co;2-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND The purpose of this study is to indicate that oxidative stress may contribute to occurrence of meningiomas. Recently, it was reported that aside from the neurofibromatosis type 2 (NF2) gene mutations, the calpain-dependent proteolysis of the NF2 gene product, merlin might be closely related to the development of certain NF2-related tumors. Although meningiomas are well known to occur more frequently in aged persons, it still remains unknown why calpain activation occurs predominantly in them. Because the production of free radicals with aging might be one of the causes of calpain activation especially in leptomeningeal cells being devoid of blood supply, the authors examined the relations between mu-calpain activation and merlin proteolysis induced by the oxidative stress. METHODS The authors examined 12 patient-derived sporadic meningiomas and their primary cultured cells. Malignant glioma cell line (U-251MG), which had no relation to NF2, was used as a control. They were exposed to hydrogen peroxide (H2O2) for 1 hour. After oxidative stress, they were examined by Western blot and immunofluorescence microscopic analyses. RESULTS Despite the consistent expressions of activated mu-calpain in 11 of 12 meningioma tissues, this calpain activation completely disappeared after culture; instead the full-length merlin appeared again in 8 of 11 cases. The treatment of cultured cells with hydrogen peroxide induced both mu-calpain-dependent cleavage of merlin and reduction of an intrinsic calpain inhibitor calpastatin. Such proteolysis was significantly blocked by a specific calpain inhibitor, Z-LLal. The full-length merlin was immunocytochemically colocalized with activated mu-calpain at the plasma membrane, and, after mu-calpain activation, the fragment of merlin translocated to the perinuclear cytoplasm or into the nucleus. CONCLUSIONS These findings suggest that oxidative stress-induced activation of mu-calpain causes proteolysis of merlin conceivably to impair cell adhesion and/or contact inhibition of meningioma cells.
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Affiliation(s)
- T Kaneko
- Department of Neurosurgery, Kanazawa University Graduate School of Medical Sciences, Kanazawa, Japan
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Welling DB, Akhmametyeva EM, Daniels RL, Lasak JM, Zhu L, Miles-Markley BA, Chang LS. Analysis of the human neurofibromatosis type 2 gene promoter and its expression. Otolaryngol Head Neck Surg 2000; 123:413-8. [PMID: 11020177 DOI: 10.1067/mhn.2000.107683] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE It is hypothesized that transcriptional regulation plays an important role for neurofibromatosis type 2 (NF2) expression in Schwann cells and other cell types. The objective of this study is the isolation and characterization of the transcriptional regulatory elements of the NF2 gene. STUDY DESIGN AND SETTING A bacterial artificial chromosome library and a partial genomic DNA library were used to isolate the human NF2 gene; NF2 promoter-luciferase constructs were generated, and promoter activities were assayed. This study was carried out in a molecular biology laboratory. RESULTS A bacterial artificial chromosome clone with an approximately 100-kilobase insert containing nearly the entire human NF2 gene has been isolated. An additional 5' NF2 sequence has also been cloned. Transient transfection experiments demonstrate strong promoter activity from the NF2 5' flanking DNA. CONCLUSIONS The NF2 gene is approximately 100 kilobases long. Both positive and negative regulatory elements are present in NF2 5' flanking regions. SIGNIFICANCE Better understanding of the NF2 gene and its regulation will improve molecular diagnostics and ultimately treatment of patients with NF2.
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Affiliation(s)
- D B Welling
- Department of Otolaryngology, Ohio State University and Children's Hospital, USA
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Nataraj AJ, Olivos-Glander I, Kusukawa N, Highsmith WE. Single-strand conformation polymorphism and heteroduplex analysis for gel-based mutation detection. Electrophoresis 1999; 20:1177-85. [PMID: 10380757 DOI: 10.1002/(sici)1522-2683(19990101)20:6<1177::aid-elps1177>3.0.co;2-2] [Citation(s) in RCA: 165] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Single-strand conformation polymorphism (SSCP) and heteroduplex analysis (HA) are popular electrophoretic methods for the identification of sequences. The principle reasons for the popularity of these two methods are their technical simplicity and their relatively high sensitivity for the detection of mutations. Here we review the theory and practice of SSCP and HA, including the factors contributing to the sensitivity of mutation detection. For SSCP analysis, these factors include: choice of gel matrix, electrophoretic conditions, presence of neutral additives, fragment size, and G+C content For HA, the principle factors influencing sensitivity are the gel matrix and the identity of the base mismatch.
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Turunen O, Sainio M, Jääskeläinen J, Carpén O, Vaheri A. Structure-function relationships in the ezrin family and the effect of tumor-associated point mutations in neurofibromatosis 2 protein. BIOCHIMICA ET BIOPHYSICA ACTA 1998; 1387:1-16. [PMID: 9748471 DOI: 10.1016/s0167-4838(98)00103-4] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Ezrin, radixin and moesin (ERM proteins) link cell adhesion molecules to the cytoskeleton, modulate cell morphology and cell growth and are involved in Rho-mediated signal transduction. Merlin, the tumor suppressor in neurofibromatosis 2, is a diverged member of the ezrin family, but its function is at least partially similar to the ERM proteins. In the N-domain, the ezrin family belongs to the band 4.1 superfamily. Secondary structure predictions made separately for the ezrin and band 4.1-tyrosine phosphatase families give a similar pattern for the homologous N-domains, indicating that both families have a similar binding site for the integral membrane proteins. The alpha-domain shows a strong coiled-coil prediction, that can be involved in the protein dimerization. The C-terminal actin-binding site in the ERM proteins and the actin-binding helix in the villin headpiece have a common amino acid motif. In merlin, the published tumor-associated single amino acid mutations in the N-domain are located in the conserved sites, and they affect mainly the predicted helices and strands, indicating that these mutations cause the disease primarily by disturbing the protein structure. In the alpha- and C-domains, some of the mutations break the helical structures. Some known mutations are observed at a site potentially interacting with cell adhesion molecules. We will also discuss the implications of the evolutionary information and the actin-binding models in the ezrin family.
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Affiliation(s)
- O Turunen
- Department of Virology, Haartman Institute, University of Helsinki, POB 21, FIN-00014 Helsinki, Finland.
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Kimura Y, Koga H, Araki N, Mugita N, Fujita N, Takeshima H, Nishi T, Yamashima T, Saido TC, Yamasaki T, Moritake K, Saya H, Nakao M. The involvement of calpain-dependent proteolysis of the tumor suppressor NF2 (merlin) in schwannomas and meningiomas. Nat Med 1998; 4:915-22. [PMID: 9701243 DOI: 10.1038/nm0898-915] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Neurofibromatosis type 2 (NF2) protein, also known as merlin or schwannomin, is a tumor suppressor, and NF2 is mutated in most schwannomas and meningiomas. Although these tumors are dependent on NF2, some lack detectable NF2 mutations, which indicates that alternative mechanisms exist for inactivating merlin. Here, we demonstrate cleavage of merlin by the ubiquitous protease calpain and considerable activation of the calpain system resulting in the loss of merlin expression in these tumors. Increased proteolysis of merlin by calpain in some schwannomas and meningiomas exemplifies tumorigenesis linked to the calpain-mediated proteolytic pathway.
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Affiliation(s)
- Y Kimura
- Department of Tumor Genetics and Biology, Kumamoto University School of Medicine, Honjo, Japan
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Bikhazi PH, Lalwani AK, Kim EJ, Bikhazi N, Attaie A, Slattery WH, Jackler RK, Brackmann DE. Germline screening of the NF-2 gene in families with unilateral vestibular schwannoma. Otolaryngol Head Neck Surg 1998; 119:1-6. [PMID: 9674507 DOI: 10.1016/s0194-5998(98)70166-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Vestibular schwannoma may present clinically in two forms: sporadic unilateral or hereditary bilateral. Familial transmission of vestibular schwannoma is known to occur only in neurofibromatosis type II (NF-2). We have previously described the clinical characteristics of unilateral vestibular schwannoma presenting in families, in the absence of ther criteria necessary for the diagnosis of NF-2. Polymerase chain reaction-single strand chain polymorphism was used to screen for germline NF-2 gene mutations in six families with unilateral vestibular schwannoma. Direct sequencing of DNA from blood was done in affected subjects from three families. No germline mutations were identified. Because NF-2 gene mutations are detected in only 33% of patients with NF-2, hereditary transmission of mutations cannot be entirely excluded. However, in the absence of germline mutations in the NF-2 gene, familial occurrence of unilateral vestibular schwannoma more likely represents either a chance somatic NF-2 gene mutation or originates from a separate genetic loci.
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Affiliation(s)
- P H Bikhazi
- Laboratory of Molecular Otology, University of California at San Francisco, 94143-0526, USA
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LaJeunesse DR, McCartney BM, Fehon RG. Structural analysis of Drosophila merlin reveals functional domains important for growth control and subcellular localization. J Cell Biol 1998; 141:1589-99. [PMID: 9647651 PMCID: PMC2133006 DOI: 10.1083/jcb.141.7.1589] [Citation(s) in RCA: 119] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/1998] [Revised: 05/14/1998] [Indexed: 02/08/2023] Open
Abstract
Merlin, the product of the Neurofibromatosis type 2 (NF2) tumor-suppressor gene, is a member of the protein 4.1 superfamily that is most closely related to ezrin, radixin, and moesin (ERM). NF2 is a dominantly inherited disease characterized by the formation of bilateral acoustic schwannomas and other benign tumors associated with the central nervous system. To understand its cellular functions, we are studying a Merlin homologue in Drosophila. As is the case for NF2 tumors, Drosophila cells lacking Merlin function overproliferate relative to their neighbors. Using in vitro mutagenesis, we define functional domains within Merlin required for proper subcellular localization and for genetic rescue of lethal Merlin alleles. Remarkably, the results of these experiments demonstrate that all essential genetic functions reside in the plasma membrane- associated NH2-terminal 350 amino acids of Merlin. Removal of a seven-amino acid conserved sequence within this domain results in a dominant-negative form of Merlin that is stably associated with the plasma membrane and causes overproliferation when expressed ectopically in the wing. In addition, we provide evidence that the COOH-terminal region of Merlin has a negative regulatory role, as has been shown for ERM proteins. These results provide insights into the functions and functional organization of a novel tumor suppressor gene.
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Affiliation(s)
- D R LaJeunesse
- Developmental, Cell and Molecular Biology Group, Department of Zoology, Duke University, Durham, North Carolina 27708-1000, USA
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Welling DB. Clinical manifestations of mutations in the neurofibromatosis type 2 gene in vestibular schwannomas (acoustic neuromas). Laryngoscope 1998; 108:178-89. [PMID: 9473065 DOI: 10.1097/00005537-199802000-00005] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Vestibular schwannomas (acoustic neuromas) continue to cause significant facial nerve and hearing morbidity, despite marked improvement in diagnosis and treatment. Mutation of a tumor-suppressor gene on human chromosome 22 has been found to be associated with vestibular schwannoma formation. The central hypothesis of this study is that specific mutations in the neurofibromatosis type 2 (NF2) gene may produce specific clinical characteristics or phenotypic expressions. The purposes of this investigation are: 1. to determine what proportion of vestibular schwannomas from patients with spontaneous unilateral and familial bilateral schwannomas have mutations present within the NF2 gene; 2. to determine whether specific types of mutations are associated with a specific clinical manifestation of this disease; and 3. to further define the relationship between newly discovered mutations within the NF2 tumor-suppressor gene and possible clinical applications of this knowledge to advance diagnosis and treatment of patients with NF2 and spontaneous vestibular schwannomas. DNA from 61 schwannomas (29 unilateral vestibular schwannomas and 32 from patients with bilateral vestibular schwannomas [NF2]) were examined, and 33 unique mutations were identified. Significant differences were found in the frequency, distribution, and type of mutation between the NF2 schwannomas and the spontaneous vestibular schwannomas. Three clinical subtypes of NF2 were identified. In tumors from 28 patients, no mutations were identified. Of the 33 mutations identified in the NF2 gene, 30 were likely to result in loss of tumor-suppressor function from protein truncation; however, three milder mutations termed missense mutations were associated with milder clinical manifestations of the disease and had a slower estimated growth rate. Variable clinical presentation in patients whose tumors had severe or truncating types of mutations suggest that factors in addition to the mutation class are likely to be responsible for a portion of the clinical expression of disease. New diagnostic options are now available for NF2 that will improve the likelihood of hearing and facial nerve preservation and ultimately have significant impact on the management of vestibular schwannomas.
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Affiliation(s)
- D B Welling
- Department of Otolaryngology, The Ohio State University, Columbus 43210, USA
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Beutler E, West C, Britton HA, Harris J, Forman L. Glucosephosphate isomerase (GPI) deficiency mutations associated with hereditary nonspherocytic hemolytic anemia (HNSHA). Blood Cells Mol Dis 1997; 23:402-9. [PMID: 9446754 DOI: 10.1006/bcmd.1997.0157] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Five unrelated patients with hereditary glucosephosphate isomerase (GPI) deficiency resulting in nonspherocytic hemolytic anemia were studied. Three new mutations were found in the coding region of the GPI gene: two patients were heterozygous for 223 A-->G (R75G) and 898 G-->C(R300P), respectively and one was homozygous for 1415G-->A(R472H). Surprisingly, 2 previously reported mutations, 286 C-->T and 1039 C-->T, were found in 2 and 3 patients respectively. Until now only 4 of 18 GPI mutations had been found more than once in unrelated patients and these 4 in only 2 patients each. Eleven of the 20 known point mutations have occurred at CpG "hot spots" and the 286 C-->T and 1039 C-->T are among these. The 489 G/A polymorphism in the GPI coding region was used to demonstrate unequivocally that the 1039 C-->T mutation occurred in both haplotypes and therefore probably originated more than once. Because no common GPI mutation has been found we suggest that heterozygosity for GPI confers little if any selective advantage.
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Affiliation(s)
- E Beutler
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
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