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El Nachef L, Berthel E, Ferlazzo ML, Le Reun E, Al-Choboq J, Restier-Verlet J, Granzotto A, Sonzogni L, Bourguignon M, Foray N. Cancer and Radiosensitivity Syndromes: Is Impaired Nuclear ATM Kinase Activity the Primum Movens? Cancers (Basel) 2022; 14:cancers14246141. [PMID: 36551628 PMCID: PMC9776478 DOI: 10.3390/cancers14246141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 12/01/2022] [Accepted: 12/09/2022] [Indexed: 12/15/2022] Open
Abstract
There are a number of genetic syndromes associated with both high cancer risk and clinical radiosensitivity. However, the link between these two notions remains unknown. Particularly, some cancer syndromes are caused by mutations in genes involved in DNA damage signaling and repair. How are the DNA sequence errors propagated and amplified to cause cell transformation? Conversely, some cancer syndromes are caused by mutations in genes involved in cell cycle checkpoint control. How is misrepaired DNA damage produced? Lastly, certain genes, considered as tumor suppressors, are not involved in DNA damage signaling and repair or in cell cycle checkpoint control. The mechanistic model based on radiation-induced nucleoshuttling of the ATM kinase (RIANS), a major actor of the response to ionizing radiation, may help in providing a unified explanation of the link between cancer proneness and radiosensitivity. In the frame of this model, a given protein may ensure its own specific function but may also play additional biological role(s) as an ATM phosphorylation substrate in cytoplasm. It appears that the mutated proteins that cause the major cancer and radiosensitivity syndromes are all ATM phosphorylation substrates, and they generally localize in the cytoplasm when mutated. The relevance of the RIANS model is discussed by considering different categories of the cancer syndromes.
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Affiliation(s)
- Laura El Nachef
- Inserm, U1296 Unit, Radiation: Defense, Health and Environment, Centre Léon-Bérard, 69008 Lyon, France
| | - Elise Berthel
- Inserm, U1296 Unit, Radiation: Defense, Health and Environment, Centre Léon-Bérard, 69008 Lyon, France
| | - Mélanie L. Ferlazzo
- Inserm, U1296 Unit, Radiation: Defense, Health and Environment, Centre Léon-Bérard, 69008 Lyon, France
| | - Eymeric Le Reun
- Inserm, U1296 Unit, Radiation: Defense, Health and Environment, Centre Léon-Bérard, 69008 Lyon, France
| | - Joelle Al-Choboq
- Inserm, U1296 Unit, Radiation: Defense, Health and Environment, Centre Léon-Bérard, 69008 Lyon, France
| | - Juliette Restier-Verlet
- Inserm, U1296 Unit, Radiation: Defense, Health and Environment, Centre Léon-Bérard, 69008 Lyon, France
| | - Adeline Granzotto
- Inserm, U1296 Unit, Radiation: Defense, Health and Environment, Centre Léon-Bérard, 69008 Lyon, France
| | - Laurène Sonzogni
- Inserm, U1296 Unit, Radiation: Defense, Health and Environment, Centre Léon-Bérard, 69008 Lyon, France
| | - Michel Bourguignon
- Inserm, U1296 Unit, Radiation: Defense, Health and Environment, Centre Léon-Bérard, 69008 Lyon, France
- Department of Biophysics and Nuclear Medicine, Université Paris Saclay (UVSQ), 78035 Versailles, France
| | - Nicolas Foray
- Inserm, U1296 Unit, Radiation: Defense, Health and Environment, Centre Léon-Bérard, 69008 Lyon, France
- Correspondence: ; Tel.: +33-04-7878-2828
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2
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Dalal S, Connelly B, Singh M, Singh K. NF2 signaling pathway plays a pro-apoptotic role in β-adrenergic receptor stimulated cardiac myocyte apoptosis. PLoS One 2018; 13:e0196626. [PMID: 29709009 PMCID: PMC5927447 DOI: 10.1371/journal.pone.0196626] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Accepted: 04/16/2018] [Indexed: 12/24/2022] Open
Abstract
β-adrenergic receptor (β-AR) stimulation induces cardiac myocyte apoptosis in vitro and in vivo. Neurofibromin 2 (NF2) is a member of the ezrin/radixin/moesin (ERM) family of proteins. Post-translational modifications such as phosphorylation and sumoylation affect NF2 activity, subcellular localization and function. Here, we tested the hypothesis that β-AR stimulation induces post-translational modifications of NF2, and NF2 plays a pro-apoptotic role in β-AR-stimulated myocyte apoptosis.
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Affiliation(s)
- Suman Dalal
- Department of Biomedical Sciences, James H Quillen College of Medicine, East Tennessee State University, Johnson City, TN, United States of America
| | - Barbara Connelly
- Department of Biomedical Sciences, James H Quillen College of Medicine, East Tennessee State University, Johnson City, TN, United States of America
| | - Mahipal Singh
- Department of Biomedical Sciences, James H Quillen College of Medicine, East Tennessee State University, Johnson City, TN, United States of America
| | - Krishna Singh
- Department of Biomedical Sciences, James H Quillen College of Medicine, East Tennessee State University, Johnson City, TN, United States of America
- Center for Inflammation, Infectious Disease and Immunity, East Tennessee State University, Johnson City, TN, United States of America
- James H Quillen Veterans Affairs Medical Center, Mountain Home, TN, United States of America
- * E-mail:
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3
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Janse van Rensburg HJ, Yang X. Essential signaling in NF2 loss-related tumours: the therapeutic potential of CRL4 DCAF1 and mTOR combined inhibition. J Thorac Dis 2017; 9:3533-3536. [PMID: 29268334 DOI: 10.21037/jtd.2017.09.34] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
| | - Xiaolong Yang
- Department of Pathology and Molecular Medicine, Queen's University, Kingston, Ontario, K7L 3N6, Canada
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4
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Zou J, Hirvonen T. "Wait and scan" management of patients with vestibular schwannoma and the relevance of non-contrast MRI in the follow-up. J Otol 2017; 12:174-184. [PMID: 29937853 PMCID: PMC6002632 DOI: 10.1016/j.joto.2017.08.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 07/29/2017] [Accepted: 08/04/2017] [Indexed: 02/04/2023] Open
Abstract
Vestibular schwannoma (VS) is a slow-growing benign neoplasm. There has been an evolution in the management of VS from active treatments (microsurgery and stereotactic radiotherapy) to conservative management (wait and scan). Regular MRI scanning is necessary to monitor tumor progression. Conservative management causes significantly less complications and offers a higher quality of life compared with active treatments. The mean growth rate of VS varies from 0.4 to 2.9 mm/year, and spontaneous shrinkage is observed in 3.8 percent of tumors during observation. If significant growth occurs, active treatment is considered. Significant growth is defined as an increase of at least 3 mm in the largest extrameatal diameter in any plane between the first and last available scans. The vestibulocochlear nerve is surrounded by cerebrospinal fluid, which provides natural contrast for MRI; thus, gadolinium may not be needed to detect VS. Specific sequences have high sensitivity, specificity, and accuracy for detection of progression. Hypointense signal in the ipsilateral inner ear fluid might be a useful sign to distinguish VS from meningioma. In this paper, we summarize the current status of research on conservative management and non-contrast MRI for the detection of VS.
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Affiliation(s)
- Jing Zou
- Department of Otolaryngology-Head and Neck Surgery, Center for Otolaryngology-Head & Neck Surgery of Chinese PLA, Changhai Hospital, Second Military Medical University, Shanghai, China
- Corresponding author. Department of Otolaryngology-Head and Neck Surgery, Changhai Hospital, Second Military Medical University, Changhai Road #168, 200433 Shanghai, China.
| | - Timo Hirvonen
- Department of Otorhinolaryngology-Head and Neck Surgery, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
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5
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Chen H, Xue L, Wang H, Wang Z, Wu H. Differential NF2 Gene Status in Sporadic Vestibular Schwannomas and its Prognostic Impact on Tumour Growth Patterns. Sci Rep 2017. [PMID: 28710469 DOI: 10.1038/srep5470] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/07/2023] Open
Abstract
The great majority of sporadic vestibular schwannomas (VSs) are due to the inactivation of the NF2 gene. In this study, we found age-dependent differences in the clinical parameters of sporadic VSs. Young patients were characterized by progressive tumour behaviours, including earlier onset of initial symptoms, shorter symptom duration and larger tumour size. An increased rate of "two-hits" of both NF2 alleles, usually by mutation and allelic loss, was observed in young cases compared to older, and this correlated with the loss of protein and mRNA expression. In contrast, the tumours with a single mutation (referred to as 'one-hit') exhibited obvious expression levels. Moreover, a mixture of merlin-expressing tumour cells and non-expressing tumour cells was observed in 'one-hit' schwannomas, suggesting that a subset of 'one-hit' tumour cells was present in these tumours. To mimic the growth promoting effects by the second hit, we performed lentivirus-mediated NF2 knockdown in the 'one-hit' schwannoma cultures. Following the loss of NF2 expression, schwannoma cultures demonstrated increased proliferation rates. Above all, we have identified a correlation between the NF2 status and the growth patterns of sporadic VSs. The treatment decision-making, microsurgery or "wait and scan" strategy, should be carried out according to the tumour's genetic background.
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Affiliation(s)
- Hongsai Chen
- Department of Otolaryngology Head & Neck Surgery, The Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Department of Otolaryngology Head and Neck Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China
| | - Lu Xue
- Department of Otolaryngology Head & Neck Surgery, The Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Department of Otolaryngology Head and Neck Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China
| | - Hantao Wang
- Department of Otolaryngology Head & Neck Surgery, The Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Department of Otolaryngology Head and Neck Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China
| | - Zhaoyan Wang
- Department of Otolaryngology Head & Neck Surgery, The Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
- Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
- Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China.
| | - Hao Wu
- Department of Otolaryngology Head & Neck Surgery, The Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
- Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
- Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China.
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6
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Chen H, Xue L, Wang H, Wang Z, Wu H. Differential NF2 Gene Status in Sporadic Vestibular Schwannomas and its Prognostic Impact on Tumour Growth Patterns. Sci Rep 2017; 7:5470. [PMID: 28710469 PMCID: PMC5511254 DOI: 10.1038/s41598-017-05769-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 06/02/2017] [Indexed: 02/06/2023] Open
Abstract
The great majority of sporadic vestibular schwannomas (VSs) are due to the inactivation of the NF2 gene. In this study, we found age-dependent differences in the clinical parameters of sporadic VSs. Young patients were characterized by progressive tumour behaviours, including earlier onset of initial symptoms, shorter symptom duration and larger tumour size. An increased rate of “two-hits” of both NF2 alleles, usually by mutation and allelic loss, was observed in young cases compared to older, and this correlated with the loss of protein and mRNA expression. In contrast, the tumours with a single mutation (referred to as ‘one-hit’) exhibited obvious expression levels. Moreover, a mixture of merlin-expressing tumour cells and non-expressing tumour cells was observed in ‘one-hit’ schwannomas, suggesting that a subset of ‘one-hit’ tumour cells was present in these tumours. To mimic the growth promoting effects by the second hit, we performed lentivirus-mediated NF2 knockdown in the ‘one-hit’ schwannoma cultures. Following the loss of NF2 expression, schwannoma cultures demonstrated increased proliferation rates. Above all, we have identified a correlation between the NF2 status and the growth patterns of sporadic VSs. The treatment decision-making, microsurgery or “wait and scan” strategy, should be carried out according to the tumour’s genetic background.
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Affiliation(s)
- Hongsai Chen
- Department of Otolaryngology Head & Neck Surgery, The Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Department of Otolaryngology Head and Neck Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China
| | - Lu Xue
- Department of Otolaryngology Head & Neck Surgery, The Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Department of Otolaryngology Head and Neck Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China
| | - Hantao Wang
- Department of Otolaryngology Head & Neck Surgery, The Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Department of Otolaryngology Head and Neck Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China
| | - Zhaoyan Wang
- Department of Otolaryngology Head & Neck Surgery, The Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China. .,Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai, China. .,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China.
| | - Hao Wu
- Department of Otolaryngology Head & Neck Surgery, The Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China. .,Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai, China. .,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China.
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7
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Li X, Chen H, Xue L, Pang X, Zhang X, Zhu Z, Zhu W, Wang Z, Wu H. p53 performs an essential role in mediating the oncogenic stimulus triggered by loss of expression of neurofibromatosis type 2 during in vitro tumor progression. Oncol Lett 2017; 14:2223-2231. [PMID: 28789444 PMCID: PMC5530008 DOI: 10.3892/ol.2017.6445] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 03/10/2017] [Indexed: 02/04/2023] Open
Abstract
The loss of the tumor suppressor neurofibromatosis type 2 gene, encoding merlin, has been considered to be a fundamental event during the malignant progression of various cell types. However, a consensus for the mainstream mechanism, by which merlin deficiency contributes to uncontrolled cellular proliferation, has not been reached. The present study aimed to determine whether silencing of merlin using lentivirus-based short hairpin RNA potentiates cellular proliferation and cell cycle progression in human colon carcinoma HCT116 cell lines, expressing p53. The present results demonstrated that merlin knockdown contributed to cellular proliferation and G1/S cell cycle progression to a greater extent in HCT116 cells wide-type for p53 (p53wt) compared with p53-null (p53−/−) cells. This was supported by overexpression experiments which demonstrated a significant inhibitory effect of excess merlin on cellular proliferation only in HCT116 p53wt cells. In order to investigate the underlying mechanisms of action, the expression of p53-involved G1/S transition genes was evaluated by western blot analysis. For HCT116 p53wt cells, merlin loss suppressed p53 expression, and therefore the dysregulation of cell cycle regulatory proteins, including p21, cyclin D1/cyclin-dependent kinase (CDK)4 and cyclin E1/CDK2 complexes. However, merlin knockdowns had no impact on the expression of any of the aforementioned molecules in p53−/− cells, indicating that lack of merlin resulted in G1/S cell cycle progression, and thereby uncontrolled cellular proliferation mainly via the regulation of p53-mediated pathways. Taken together, it was proposed that p53 performs an essential role in mediating the oncogenic stimulus triggered by merlin loss, and p53 is a molecule that should be investigated for its potential in targeted drug therapy for merlin-deficient malignancies.
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Affiliation(s)
- Xiye Li
- Department of Otolaryngology Head and Neck Surgery, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, P.R. China.,Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, P.R. China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai 200092, P.R. China
| | - Hongsai Chen
- Department of Otolaryngology Head and Neck Surgery, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, P.R. China.,Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, P.R. China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai 200092, P.R. China
| | - Lu Xue
- Department of Otolaryngology Head and Neck Surgery, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, P.R. China.,Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, P.R. China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai 200092, P.R. China
| | - Xiuhong Pang
- Department of Otolaryngology Head and Neck Surgery, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, P.R. China.,Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, P.R. China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai 200092, P.R. China
| | - Xiaoman Zhang
- Department of Otolaryngology Head and Neck Surgery, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, P.R. China.,Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, P.R. China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai 200092, P.R. China
| | - Zhengjie Zhu
- Department of Otolaryngology Head and Neck Surgery, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, P.R. China.,Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, P.R. China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai 200092, P.R. China
| | - Weidong Zhu
- Department of Otolaryngology Head and Neck Surgery, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, P.R. China.,Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, P.R. China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai 200092, P.R. China
| | - Zhaoyan Wang
- Department of Otolaryngology Head and Neck Surgery, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, P.R. China.,Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, P.R. China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai 200092, P.R. China
| | - Hao Wu
- Department of Otolaryngology Head and Neck Surgery, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, P.R. China.,Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, P.R. China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai 200092, P.R. China
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8
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Håvik AL, Bruland O, Myrseth E, Miletic H, Aarhus M, Knappskog PM, Lund-Johansen M. Genetic landscape of sporadic vestibular schwannoma. J Neurosurg 2017; 128:911-922. [PMID: 28409725 DOI: 10.3171/2016.10.jns161384] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
OBJECTIVE Vestibular schwannoma (VS) is a benign tumor with associated morbidities and reduced quality of life. Except for mutations in NF2, the genetic landscape of VS remains to be elucidated. Little is known about the effect of Gamma Knife radiosurgery (GKRS) on the VS genome. The aim of this study was to characterize mutations occurring in this tumor to identify new genes and signaling pathways important for the development of VS. In addition, the authors sought to evaluate whether GKRS resulted in an increase in the number of mutations. METHODS Forty-six sporadic VSs, including 8 GKRS-treated tumors and corresponding blood samples, were subjected to whole-exome sequencing and tumor-specific DNA variants were called. Pathway analysis was performed using the Ingenuity Pathway Analysis software. In addition, multiplex ligation-dependent probe amplification was performed to characterize copy number variations in the NF2 gene, and microsatellite instability testing was done to investigate for DNA replication error. RESULTS With the exception of a single sample with an aggressive phenotype that harbored a large number of mutations, most samples showed a relatively low number of mutations. A median of 14 tumor-specific mutations in each sample were identified. The GKRS-treated tumors harbored no more mutations than the rest of the group. A clustering of mutations in the cancer-related axonal guidance pathway was identified (25 patients), as well as mutations in the CDC27 (5 patients) and USP8 (3 patients) genes. Thirty-five tumors harbored mutations in NF2 and 16 tumors had 2 mutational hits. The samples without detectable NF2 mutations harbored mutations in genes that could be linked to NF2 or to NF2-related functions. None of the tumors showed microsatellite instability. CONCLUSIONS The genetic landscape of VS seems to be quite heterogeneous; however, most samples had mutations in NF2 or in genes that could be linked to NF2. The results of this study do not link GKRS to an increased number of mutations.
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Affiliation(s)
- Aril Løge Håvik
- Departments of1Clinical Medicine.,2Center for Medical Genetics and Molecular Medicine, and.,3Clinical Science, and
| | - Ove Bruland
- 2Center for Medical Genetics and Molecular Medicine, and
| | | | - Hrvoje Miletic
- 5Pathology, Haukeland University Hospital, Bergen; and.,6K.G. Jebsen Brain Tumor Research Center, University of Bergen.,7Biomedicine, and
| | - Mads Aarhus
- 8Department of Neurosurgery, Oslo University Hospitals, Ullevål Sykehus, Oslo,Norway
| | - Per-Morten Knappskog
- 2Center for Medical Genetics and Molecular Medicine, and.,3Clinical Science, and
| | - Morten Lund-Johansen
- Departments of1Clinical Medicine.,Departments of4Neurosurgery and.,6K.G. Jebsen Brain Tumor Research Center, University of Bergen
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Qi Q, Liu X, Brat DJ, Ye K. Merlin sumoylation is required for its tumor suppressor activity. Oncogene 2013; 33:4893-903. [PMID: 24166499 DOI: 10.1038/onc.2013.438] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Revised: 08/01/2013] [Accepted: 08/12/2013] [Indexed: 12/11/2022]
Abstract
Merlin, encoded by the Neurofibromatosis 2 (NF2) gene, is a multifunctional tumor suppressor that integrates and regulates extracellular cues and intracellular signaling pathways, both at the plasma membrane and in the nucleus, to control cell proliferation, migration and invasion. Molecular mechanisms regulating merlin's tumor-suppressive activity have not been clearly defined. Here we report that merlin can be sumoylated on Lysine residue (K76) in vitro and in vivo. Sumoylation mediates merlin's intramolecular and intermolecular binding activities and regulates its cytoplasm/nucleus trafficking. Interestingly, sumoylation of merlin is regulated by its phosphorylation via Akt and PAK2 kinases. Mutation of K76 into arginine (R) abolishes its sumoylation, disrupts merlin cortical cytoskeleton residency and attenuates its stability. Using a K76R mutant merlin in a subcutaneous U87MG xenograft model, we demonstrate that merlin sumoylation is required for tumor-suppressive activity. Taken together, our findings indicate that merlin is sumoylated and that this post-translational modification is essential for tumor suppression.
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Affiliation(s)
- Q Qi
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA, USA
| | - X Liu
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA, USA
| | - D J Brat
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA, USA
| | - K Ye
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA, USA
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10
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Abstract
HYPOTHESIS The proto-oncogen cyclin D1 has been implicated in the development and behavior of vestibular schwannoma. This study evaluates the association between cyclin D1 expression and other known prognostic factors in facial function outcome 1 year after vestibular schwannoma surgery. METHODS Sixty-four patients undergoing surgery for vestibular schwannoma were studied. Immunohistochemistry analysis was performed with anticyclin D1 in all cases. Cyclin D1 expression, as well as other demographic, clinical, radiologic, and intraoperative data, was correlated with 1-year postoperative facial function. RESULTS Good 1-year facial function (Grades 1-2) was achieved in 73% of cases. Cyclin D1 expression was found in 67% of the tumors. Positive cyclin D1 staining was more frequent in patients with Grades 1 to 2 (75%) than in those with Grades 3 to 6 (25%). Other significant variables were tumor volume and facial nerve stimulation after tumor resection. The area under the receiver operating characteristics curve increased when adding cyclin D1 expression to the multivariate model. CONCLUSION Cyclin D1 expression is associated to facial outcome after vestibular schwannoma surgery. The prognostic value of cyclin D1 expression is independent of tumor size and facial nerve stimulation at the end of surgery.
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