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Florou C, Aissopou E, Chalkiadaki E, Andreanos K, Koutsandrea C, Papaconstantinou D, Georgalas I. Corneal endothelial cells and central corneal thickness in patients with neurofibromatosis type 1. Indian J Ophthalmol 2021; 69:1522-1526. [PMID: 34011734 PMCID: PMC8302278 DOI: 10.4103/ijo.ijo_1967_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose: The aim of this study was to evaluate the morphological properties of corneal endothelial cells and central corneal thickness (CCT) in patients with neurofibromatosis type 1 (NF1) and to compare them with age-matched healthy controls. Methods: Nineteen NF1 patients and 38 healthy individuals were recruited. All participants underwent complete ophthalmological examination as well as noncontact specular microscopy to measure endothelial cell density (ECD), average cell area (AVG), coefficient of variation of cell area (CV), the percentage of hexagonal cells, and CCT. Eyes with previous ocular trauma, inflammation or surgery, and preexisting corneal and ocular surface diseases were excluded. Results: NF1 patients had higher ECD compared to healthy controls of the same age (2764.2 ± 270.4 versus 2570.4 ± 449.2 cells/mm, respectively), although at a borderline level (P = 0.051). Patients with NF1 presented significantly lower CV and AVG when compared to controls (32.9 ± 4.6 versus 37.8 ± 9.5%, P = 0.011 and 364.9 ± 34.4 versus 406.0 ± 107.4 µm, P = 0.038, respectively). The NF1 group had significantly higher hexagonality in comparison with controls (55.7 ± 6.5 versus 50.5 ± 9.9%, P = 0.025). CCT was similar between the two groups (P = 0.955). Conclusion: Our results show that corneal endothelium has more favorable morphological characteristics in NF1 patients compared to healthy individuals of the same age.
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Affiliation(s)
- Chrysoula Florou
- First Department of Ophthalmology, National and Kapodistrian University of Athens, General Hospital "G. Gennimatas", Athens, Greece
| | - Evaggelia Aissopou
- Ophthalmologist in Private Office, Papadiamantopoulou 186, Athens, Greece
| | - Evangelia Chalkiadaki
- First Department of Ophthalmology, National and Kapodistrian University of Athens, General Hospital "G. Gennimatas", Athens, Greece
| | | | - Chrysanthi Koutsandrea
- First Department of Ophthalmology, National and Kapodistrian University of Athens, General Hospital "G. Gennimatas", Athens, Greece
| | - Dimitrios Papaconstantinou
- First Department of Ophthalmology, National and Kapodistrian University of Athens, General Hospital "G. Gennimatas", Athens, Greece
| | - Ilias Georgalas
- First Department of Ophthalmology, National and Kapodistrian University of Athens, General Hospital "G. Gennimatas", Athens, Greece
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Lauri A, Fasano G, Venditti M, Dallapiccola B, Tartaglia M. In vivo Functional Genomics for Undiagnosed Patients: The Impact of Small GTPases Signaling Dysregulation at Pan-Embryo Developmental Scale. Front Cell Dev Biol 2021; 9:642235. [PMID: 34124035 PMCID: PMC8194860 DOI: 10.3389/fcell.2021.642235] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 03/12/2021] [Indexed: 12/24/2022] Open
Abstract
While individually rare, disorders affecting development collectively represent a substantial clinical, psychological, and socioeconomic burden to patients, families, and society. Insights into the molecular mechanisms underlying these disorders are required to speed up diagnosis, improve counseling, and optimize management toward targeted therapies. Genome sequencing is now unveiling previously unexplored genetic variations in undiagnosed patients, which require functional validation and mechanistic understanding, particularly when dealing with novel nosologic entities. Functional perturbations of key regulators acting on signals' intersections of evolutionarily conserved pathways in these pathological conditions hinder the fine balance between various developmental inputs governing morphogenesis and homeostasis. However, the distinct mechanisms by which these hubs orchestrate pathways to ensure the developmental coordinates are poorly understood. Integrative functional genomics implementing quantitative in vivo models of embryogenesis with subcellular precision in whole organisms contribute to answering these questions. Here, we review the current knowledge on genes and mechanisms critically involved in developmental syndromes and pediatric cancers, revealed by genomic sequencing and in vivo models such as insects, worms and fish. We focus on the monomeric GTPases of the RAS superfamily and their influence on crucial developmental signals and processes. We next discuss the effectiveness of exponentially growing functional assays employing tractable models to identify regulatory crossroads. Unprecedented sophistications are now possible in zebrafish, i.e., genome editing with single-nucleotide precision, nanoimaging, highly resolved recording of multiple small molecules activity, and simultaneous monitoring of brain circuits and complex behavioral response. These assets permit accurate real-time reporting of dynamic small GTPases-controlled processes in entire organisms, owning the potential to tackle rare disease mechanisms.
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Affiliation(s)
- Antonella Lauri
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy
| | | | | | | | - Marco Tartaglia
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy
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Revised diagnostic criteria for neurofibromatosis type 1 and Legius syndrome: an international consensus recommendation. Genet Med 2021; 23:1506-1513. [PMID: 34012067 PMCID: PMC8354850 DOI: 10.1038/s41436-021-01170-5] [Citation(s) in RCA: 248] [Impact Index Per Article: 82.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 03/21/2021] [Accepted: 03/26/2021] [Indexed: 01/08/2023] Open
Abstract
Purpose By incorporating major developments in genetics, ophthalmology, dermatology, and neuroimaging, to revise the diagnostic criteria for neurofibromatosis type 1 (NF1) and to establish diagnostic criteria for Legius syndrome (LGSS). Methods We used a multistep process, beginning with a Delphi method involving global experts and subsequently involving non-NF experts, patients, and foundations/patient advocacy groups. Results We reached consensus on the minimal clinical and genetic criteria for diagnosing and differentiating NF1 and LGSS, which have phenotypic overlap in young patients with pigmentary findings. Criteria for the mosaic forms of these conditions are also recommended. Conclusion The revised criteria for NF1 incorporate new clinical features and genetic testing, whereas the criteria for LGSS were created to differentiate the two conditions. It is likely that continued refinement of these new criteria will be necessary as investigators (1) study the diagnostic properties of the revised criteria, (2) reconsider criteria not included in this process, and (3) identify new clinical and other features of these conditions. For this reason, we propose an initiative to update periodically the diagnostic criteria for NF1 and LGSS. ![]()
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Metalloproteinase 1 downregulation in neurofibromatosis 1: Therapeutic potential of antimalarial hydroxychloroquine and chloroquine. Cell Death Dis 2021; 12:513. [PMID: 34011935 PMCID: PMC8134427 DOI: 10.1038/s41419-021-03802-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 04/30/2021] [Accepted: 04/30/2021] [Indexed: 02/07/2023]
Abstract
Neurofibromatosis type 1 is an autosomal dominant genetic disorder caused by mutation in the neurofibromin 1 (NF1) gene. Its hallmarks are cutaneous findings including neurofibromas, benign peripheral nerve sheath tumors. We analyzed the collagen and matrix metalloproteinase 1 (MMP1) expression in Neurofibromatosis 1 cutaneous neurofibroma and found excessive expression of collagen and reduced expression of MMP1. To identify new therapeutic drugs for neurofibroma, we analyzed phosphorylation of components of the Ras pathway, which underlies NF1 regulation, and applied treatments to block this pathway (PD184352, U0126, and rapamycin) and lysosomal processes (chloroquine (CQ), hydroxychloroquine (HCQ), and bafilomycin A (BafA)) in cultured Neurofibromatosis 1 fibroblasts. We found that downregulation of the MMP1 protein was a key abnormal feature in the neurofibromatosis 1 fibroblasts and that the decreased MMP1 was restored by the lysosomal blockers CQ and HCQ, but not by the blockers of the Ras pathway. Moreover, the MMP1-upregulating activity of those lysosomal blockers was dependent on aryl hydrocarbon receptor (AHR) activation and ERK phosphorylation. Our findings suggest that lysosomal blockers are potential candidates for the treatment of Neurofibromatosis 1 neurofibroma.
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Coincidental Expression of Classic Hodgkin Lymphoma and Neurofibromatosis Type I and Literature Review. J Pediatr Hematol Oncol 2021; 43:e535-e538. [PMID: 32366782 DOI: 10.1097/mph.0000000000001811] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 03/25/2020] [Indexed: 10/24/2022]
Abstract
Neurofibromatosis Type 1 (NF1) is a genetic disorder with an incidence of 1 in 2600 to 3000 individuals. It is a clinical diagnosis characterized by café-au-lait macules, neurofibromas, and axillary and/or groin freckling. Because of genetic mutations in the NF1 gene affecting the Ras/mitogen-activated protein kinase pathway, there is also risk of associated soft tissue sarcomas and hematologic malignancies. However, reports of classic Hodgkin lymphoma in patients with NF1 are sparse. We report an adolescent with NF1 who developed classic Hodgkin lymphoma. Although there is an unclear association between mutations in the NF1 gene and classic Hodgkin lymphoma, further studies are warranted.
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Zhang T, Jia C, Dong Z, Li C, Lu W. A novel mutation in NF1 gene of patient with Neurofibromatosis type 1: A case report and functional study. Mol Genet Genomic Med 2021; 9:e1643. [PMID: 33764694 PMCID: PMC8172195 DOI: 10.1002/mgg3.1643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 01/17/2021] [Accepted: 02/10/2021] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Neurofibromatosis type 1 is an autosomal dominant inherited disease and caused by NF1 gene mutation. Its clinical manifestations include multiple cafe´-au lait (CAL) spots, skinfold freckling, neurofibroma, bone dysplasia, learning disabilities, and an increased risk of malignancy. METHODS AND RESULTS Here, we reported a Chinese patient bearing with a novel NF1 mutation (c.2064delGGATGCAGCGG/p.Gly672AsnfsTer24) and complaining mainly about bone phenotype. Functional studies found that this novel mutation caused the damage of NF1 mRNA and protein levels, and lost the inhibition on Ras/Erk signaling. CONCLUSION A novel mutation in NF1 gene was identified and in vitro functional studies were performed, which provided a potential molecular mechanism to explain the bone maldevelopment of patients with neurofibromatosis type 1.
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Affiliation(s)
- Tingting Zhang
- Department of PediatricsRuijin Hospital Affiliated to Shanghai Jiao Tong UniversityShanghaiChina
| | - Caiwei Jia
- Cancer CenterShanghai Tenth People’s HospitalSchool of MedicineTongji UniversityShanghaiChina
| | - Zhiya Dong
- Department of PediatricsRuijin Hospital Affiliated to Shanghai Jiao Tong UniversityShanghaiChina
| | - Chuanyin Li
- Cancer CenterShanghai Tenth People’s HospitalSchool of MedicineTongji UniversityShanghaiChina
| | - Wenli Lu
- Department of PediatricsRuijin Hospital Affiliated to Shanghai Jiao Tong UniversityShanghaiChina
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Choi HJ, Yoon JH, Son BJ, Hwang SK, Chun BY. Retinal Microvascular Abnormalities in Patients with Type I Neurofibromatosis. JOURNAL OF THE KOREAN OPHTHALMOLOGICAL SOCIETY 2021. [DOI: 10.3341/jkos.2021.62.2.266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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58
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Shinozaki H, Sasakura Y, Shinozaki S, Terauchi T, Matsui J, Kobayashi K, Lefor AK, Ogata Y. Cystic Pancreatic Neuroendocrine Tumor in a Patient with Neurofibromatosis Type 1. Case Rep Gastroenterol 2021; 15:108-114. [PMID: 33708057 PMCID: PMC7923728 DOI: 10.1159/000510210] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 07/10/2020] [Indexed: 12/27/2022] Open
Abstract
Neurofibromatosis type 1 (NF-1) is strongly associated with neurofibromas and malignancies. Solid pancreatic neuroendocrine tumors (PanNETs) have been recently reported in patients with NF-1. PanNETs are always solid and rarely present with a cystic appearance due to central necrosis and hemorrhage caused by rapid growth. A 33-year-old female diagnosed with NF-1 at age 16 was referred for evaluation of a pelvic mass found on abdominal ultrasound. Magnetic resonance imaging showed a 6 cm solid pelvic mass adjacent to the left external iliac artery, and contrast-enhanced computed tomography scan showed a 3-cm solid para-aortic mass and a 3-cm cystic mass in the pancreatic tail. Endoscopic ultrasonography showed a cystic tumor with necrotic tissue and septa. Preoperative diagnosis was pancreatic cystic malignancy with para-aortic lymph node metastasis accompanied with a pelvic neurofibroma. These lesions were resected simultaneously. The specimen resected from the pancreas showed a necrotizing cystic tumor invading abutting lymph nodes. Immunohistochemical analysis showed positive chromogranin A and synaptophysin. The Ki-67 index was <1%, and the mitotic count was 1/10 in high power field. Therefore, a non-functional PanNET (grade G1) was diagnosed. The pelvic and para-aortic tumors were both neurofibromas. A cystic appearance is atypical for PanNET and makes preoperative diagnosis difficult. To the best of our knowledge, this is the first report of a cystic PanNET in a patient with NF-1.
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Affiliation(s)
| | - Yuuichi Sasakura
- Department of Surgery, Saiseikai Utsunomiya Hospital, Utsunomiya, Japan
| | - Satoshi Shinozaki
- Shinozaki Medical Clinic, Utsunomiya, Japan.,Division of Gastroenterology, Department of Medicine, Jichi Medical University, Shimotsuke, Japan
| | - Toshiaki Terauchi
- Department of Surgery, Saiseikai Utsunomiya Hospital, Utsunomiya, Japan
| | - Junichi Matsui
- Department of Surgery, Tokyo Dental College Ichikawa General Hospital, Tokyo, Japan
| | - Kenji Kobayashi
- Department of Surgery, Saiseikai Utsunomiya Hospital, Utsunomiya, Japan
| | | | - Yoshiro Ogata
- Department of Surgery, Saiseikai Utsunomiya Hospital, Utsunomiya, Japan
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Neira JL, Vega S, Martínez-Rodríguez S, Velázquez-Campoy A. The isolated GTPase-activating-protein-related domain of neurofibromin-1 has a low conformational stability in solution. Arch Biochem Biophys 2021; 700:108767. [PMID: 33476564 DOI: 10.1016/j.abb.2021.108767] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 01/07/2021] [Accepted: 01/11/2021] [Indexed: 11/28/2022]
Abstract
Neurofibromin-1 (NF1) is a large, multidomain tumour suppressor encoded by the NF1 gene. The gene is mutated in neurofibromatosis type I, a disease characterized by malignant tumours of the nervous system and benign neurofibromas. The best-known activity of NF1 is the down-regulation of the mitogen-activated protein kinase pathway via its three-hundred-residue-long GTPase-activating protein (GAP) domain (the so-called GAP-related domain (NF1-GRD)). The NF1-GRD stimulates Ras GTPase activity in turning off signalling. Despite this activity, NF1-GRD has been demonstrated to bind to other different proteins, such as SPRED1 or MC1R. We have embarked on the biophysical and conformational characterization of NF1-GRD in solution by using several spectroscopic (namely fluorescence and circular dichroism (CD)) and biophysical techniques (namely size exclusion chromatography (SEC) and differential scanning calorimetry (DSC)). This biophysical characterization is crucial in deciphering NF1-GRD interactome and in finding biochemical features, modulating possible protein interactions. The native-like structure of NF1-GRD (as monitored by intrinsic fluorescence and far-UV CD) was strongly pH-dependent showing a pH-titration causing a substantial increase in its helicity. NF1-GRD had a low conformational stability, as concluded from DSC experiments and thermal denaturations followed by intrinsic and ANS fluorescence, and CD. Chemical denaturations showed that NF1-GRD unfolded through an intermediate which has a substantial amount of solvent-exposed hydrophobic patches.
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Affiliation(s)
- José L Neira
- IDIBE, Universidad Miguel Hernández, 03202, Elche, Alicante, Spain; Instituto de Biocomputación y Física de Sistemas Complejos, Joint Units IQFR-CSIC-BIFI, and GBsC-CSIC-BIFI, Universidad de Zaragoza, 50009, Zaragoza, Spain.
| | - Sonia Vega
- Instituto de Biocomputación y Física de Sistemas Complejos, Joint Units IQFR-CSIC-BIFI, and GBsC-CSIC-BIFI, Universidad de Zaragoza, 50009, Zaragoza, Spain
| | - Sergio Martínez-Rodríguez
- Laboratorio de Estudios Cristalográficos, CSIC, 18100, Armilla, Granada, Spain; Dpto. Bioquímica y Biología Molecular III e Inmunología, Facultad de Medicina, Universidad de Granada, 18071, Granada, Spain.
| | - Adrián Velázquez-Campoy
- Instituto de Biocomputación y Física de Sistemas Complejos, Joint Units IQFR-CSIC-BIFI, and GBsC-CSIC-BIFI, Universidad de Zaragoza, 50009, Zaragoza, Spain; Instituto de Investigación Sanitaria Aragón (IIS Aragón), 50009, Zaragoza, Spain; Fundación ARAID, Government of Aragón, 50009, Zaragoza, Spain; Departamento de Bioquímica y Biología Molecular y Celular, Universidad de Zaragoza, 50009, Zaragoza, Spain; Centro de Investigación Biomédica en Red en el Área Temática de Enfermedades Hepáticas y Digestivas (CIBERehd), 28006, Madrid, Spain
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Malaquias AC, Jorge AAL. Activation of the MAPK pathway (RASopathies) and partial growth hormone insensitivity. Mol Cell Endocrinol 2021; 519:111040. [PMID: 33011209 DOI: 10.1016/j.mce.2020.111040] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 09/12/2020] [Accepted: 09/25/2020] [Indexed: 12/19/2022]
Abstract
RASopathies are a heterogeneous group of syndromes caused by germline mutations in genes encoding components of the RAS/MAPK pathway. Postnatal short stature is a cardinal feature of the RASopathies. Although the pathophysiology of these conditions is not fully understood to date, growth hormone insensitivity is one possibility, based on the observation of low IGF-1 values, generally preserved GH secretion and suboptimal growth response to recombinant human GH therapy. In this review, we will discuss the clinical and experimental evidence of GH insensitivity in patients with Noonan syndrome and other RASopathies, as well as their molecular basis.
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Affiliation(s)
- Alexsandra C Malaquias
- Unidade de Endocrinologia Genética, Laboratório de Endocrinologia Celular e Molecular LIM25, Disciplina de Endocrinologia da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil; Unidade de Endocrinologia Pediátrica, Departamento de Pediatria, Irmandade da Santa Casa de Misericórdia de São Paulo, Faculdade de Ciências Médicas da Santa Casa de São Paulo, São Paulo, Brazil
| | - Alexander A L Jorge
- Unidade de Endocrinologia Genética, Laboratório de Endocrinologia Celular e Molecular LIM25, Disciplina de Endocrinologia da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
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Kameneva P, Kastriti ME, Adameyko I. Neuronal lineages derived from the nerve-associated Schwann cell precursors. Cell Mol Life Sci 2021; 78:513-529. [PMID: 32748156 PMCID: PMC7873084 DOI: 10.1007/s00018-020-03609-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 05/18/2020] [Accepted: 07/22/2020] [Indexed: 12/26/2022]
Abstract
For a long time, neurogenic placodes and migratory neural crest cells were considered the immediate sources building neurons of peripheral nervous system. Recently, a number of discoveries revealed the existence of another progenitor type-a nerve-associated multipotent Schwann cell precursors (SCPs) building enteric and parasympathetic neurons as well as neuroendocrine chromaffin cells. SCPs are neural crest-derived and are similar to the crest cells by their markers and differentiation potential. Such similarities, but also considerable differences, raise many questions pertaining to the medical side, fundamental developmental biology and evolution. Here, we discuss the genesis of Schwann cell precursors, their role in building peripheral neural structures and ponder on their role in the origin in congenial diseases associated with peripheral nervous systems.
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Affiliation(s)
- Polina Kameneva
- Department of Physiology and Pharmacology, Karolinska Institute, Stockholm, 171 77, Sweden
| | - Maria Eleni Kastriti
- Department of Physiology and Pharmacology, Karolinska Institute, Stockholm, 171 77, Sweden
- Department of Molecular Neurosciences, Center for Brain Research, Medical University Vienna, Vienna, 1090, Austria
| | - Igor Adameyko
- Department of Physiology and Pharmacology, Karolinska Institute, Stockholm, 171 77, Sweden.
- Department of Molecular Neurosciences, Center for Brain Research, Medical University Vienna, Vienna, 1090, Austria.
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Cabozantinib for neurofibromatosis type 1-related plexiform neurofibromas: a phase 2 trial. Nat Med 2021; 27:165-173. [PMID: 33442015 PMCID: PMC8275010 DOI: 10.1038/s41591-020-01193-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 11/25/2020] [Indexed: 01/29/2023]
Abstract
Neurofibromatosis type 1 (NF1) plexiform neurofibromas (PNs) are progressive, multicellular neoplasms that cause morbidity and may transform to sarcoma. Treatment of Nf1fl/fl;Postn-Cre mice with cabozantinib, an inhibitor of multiple tyrosine kinases, caused a reduction in PN size and number and differential modulation of kinases in cell lineages that drive PN growth. Based on these findings, the Neurofibromatosis Clinical Trials Consortium conducted a phase II, open-label, nonrandomized Simon two-stage study to assess the safety, efficacy and biologic activity of cabozantinib in patients ≥16 years of age with NF1 and progressive or symptomatic, inoperable PN ( NCT02101736 ). The trial met its primary outcome, defined as ≥25% of patients achieving a partial response (PR, defined as ≥20% reduction in target lesion volume as assessed by magnetic resonance imaging (MRI)) after 12 cycles of therapy. Secondary outcomes included adverse events (AEs), patient-reported outcomes (PROs) assessing pain and quality of life (QOL), pharmacokinetics (PK) and the levels of circulating endothelial cells and cytokines. Eight of 19 evaluable (42%) trial participants achieved a PR. The median change in tumor volume was 15.2% (range, +2.2% to -36.9%), and no patients had disease progression while on treatment. Nine patients required dose reduction or discontinuation of therapy due to AEs; common AEs included gastrointestinal toxicity, hypothyroidism, fatigue and palmar plantar erythrodysesthesia. A total of 11 grade 3 AEs occurred in eight patients. Patients with PR had a significant reduction in tumor pain intensity and pain interference in daily life but no change in global QOL scores. These data indicate that cabozantinib is active in NF1-associated PN, resulting in tumor volume reduction and pain improvement.
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Engler M, Fidan M, Nandi S, Cirstea IC. Senescence in RASopathies, a possible novel contributor to a complex pathophenoype. Mech Ageing Dev 2020; 194:111411. [PMID: 33309600 DOI: 10.1016/j.mad.2020.111411] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 11/17/2020] [Accepted: 11/23/2020] [Indexed: 01/07/2023]
Abstract
Senescence is a biological process that induces a permanent cell cycle arrest and a specific gene expression program in response to various stressors. Following studies over the last few decades, the concept of senescence has evolved from an antiproliferative mechanism in cancer (oncogene-induced senescence) to a critical component of physiological processes associated with embryonic development, tissue regeneration, ageing and its associated diseases. In somatic cells, oncogenic mutations in RAS-MAPK pathway genes are associated with oncogene-induced senescence and cancer, while germline mutations in the same pathway are linked to a group of monogenic developmental disorders generally termed RASopathies. Here, we consider that in these disorders, senescence induction may result in opposing outcomes, a tumour protective effect and a possible contributor to a premature ageing phenotype identified in Costello syndrome, which belongs to the RASopathy group. In this review, we will highlight the role of senescence in organismal homeostasis and we will describe the current knowledge about senescence in RASopathies. Additionally, we provide a perspective on examples of experimentally characterised RASopathy mutations that, alone or in combination with various stressors, may also trigger an age-dependent chronic senescence, possibly contributing to the age-dependent worsening of RASopathy pathophenotype and the reduction of lifespan.
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Affiliation(s)
- Melanie Engler
- Institute of Comparative Molecular Endocrinology, Ulm University, Helmholtzstr. 8/1, 89081, Ulm, Germany
| | - Miray Fidan
- Institute of Comparative Molecular Endocrinology, Ulm University, Helmholtzstr. 8/1, 89081, Ulm, Germany
| | - Sayantan Nandi
- Institute of Comparative Molecular Endocrinology, Ulm University, Helmholtzstr. 8/1, 89081, Ulm, Germany
| | - Ion Cristian Cirstea
- Institute of Comparative Molecular Endocrinology, Ulm University, Helmholtzstr. 8/1, 89081, Ulm, Germany.
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Bergoug M, Doudeau M, Godin F, Mosrin C, Vallée B, Bénédetti H. Neurofibromin Structure, Functions and Regulation. Cells 2020; 9:cells9112365. [PMID: 33121128 PMCID: PMC7692384 DOI: 10.3390/cells9112365] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 10/21/2020] [Accepted: 10/26/2020] [Indexed: 12/13/2022] Open
Abstract
Neurofibromin is a large and multifunctional protein encoded by the tumor suppressor gene NF1, mutations of which cause the tumor predisposition syndrome neurofibromatosis type 1 (NF1). Over the last three decades, studies of neurofibromin structure, interacting partners, and functions have shown that it is involved in several cell signaling pathways, including the Ras/MAPK, Akt/mTOR, ROCK/LIMK/cofilin, and cAMP/PKA pathways, and regulates many fundamental cellular processes, such as proliferation and migration, cytoskeletal dynamics, neurite outgrowth, dendritic-spine density, and dopamine levels. The crystallographic structure has been resolved for two of its functional domains, GRD (GAP-related (GTPase-activating protein) domain) and SecPH, and its post-translational modifications studied, showing it to be localized to several cell compartments. These findings have been of particular interest in the identification of many therapeutic targets and in the proposal of various therapeutic strategies to treat the symptoms of NF1. In this review, we provide an overview of the literature on neurofibromin structure, function, interactions, and regulation and highlight the relationships between them.
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Tao J, Sun D, Dong L, Zhu H, Hou H. Advancement in research and therapy of NF1 mutant malignant tumors. Cancer Cell Int 2020; 20:492. [PMID: 33061844 PMCID: PMC7547409 DOI: 10.1186/s12935-020-01570-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 09/23/2020] [Indexed: 12/27/2022] Open
Abstract
The NF1 gene encodes neurofibromin, which is one of the primary negative regulatory factors of the Ras protein. Neurofibromin stimulates the GTPase activity of Ras to convert it from an active GTP-bound form to its inactive GDP-bound form through its GTPase activating protein-related domain (GRD). Therefore, neurofibromin serves as a shutdown signal for all vertebrate RAS GTPases. NF1 mutations cause a resultant decrease in neurofibromin expression, which has been detected in many human malignancies, including NSCLC, breast cancer and so on. NF1 mutations are associated with the underlying mechanisms of treatment resistance discovered in multiple malignancies. This paper reviews the possible mechanisms of NF1 mutation-induced therapeutic resistance to chemotherapy, endocrine therapy and targeted therapy in malignancies. Then, we further discuss advancements in targeted therapy for NF1-mutated malignant tumors. In addition, therapies targeting the downstream molecules of NF1 might be potential novel strategies for the treatment of advanced malignancies.
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Affiliation(s)
- Junyan Tao
- Precision Medicine Center of Oncology, the Affiliated Hospital of Qingdao University, No. 59 Haier Road, Qingdao, Shandong 266000 China
| | - Dantong Sun
- Precision Medicine Center of Oncology, the Affiliated Hospital of Qingdao University, No. 59 Haier Road, Qingdao, Shandong 266000 China
| | - Lina Dong
- Precision Medicine Center of Oncology, the Affiliated Hospital of Qingdao University, No. 59 Haier Road, Qingdao, Shandong 266000 China
| | - Hua Zhu
- Precision Medicine Center of Oncology, the Affiliated Hospital of Qingdao University, No. 59 Haier Road, Qingdao, Shandong 266000 China
| | - Helei Hou
- Precision Medicine Center of Oncology, the Affiliated Hospital of Qingdao University, No. 59 Haier Road, Qingdao, Shandong 266000 China
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Craniofacial bone alterations in patients with neurofibromatosis type 1. Childs Nerv Syst 2020; 36:2391-2399. [PMID: 32583151 DOI: 10.1007/s00381-020-04749-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Accepted: 06/16/2020] [Indexed: 12/26/2022]
Abstract
Osseous manifestations of neurofibromatosis 1 (NF-1) occur in a minority of the affected subjects but may be because of significant clinical impairment. Typically, they involve the long bones, commonly the tibia and the fibula, the vertebrae, and the sphenoid wing. The pathogenesis of NF-1 focal osseous lesions and its possible relationships with other osseous NF-1 anomalies leading to short stature are still unknown, though it is likely that they depend on a common mechanism acting in a specific subgroup of NF-1 patients. Indeed, NF-1 gene product, neurofibromin, is expressed in all the cells that participate to bone growth: osteoblasts, osteoclasts, chondrocytes, fibroblasts, and vascular endothelial cells. Absent or low content of neurofibromin may be responsible for the osseous manifestations associated to NF-1. Among the focal NF-1 osseous anomalies, the agenesis of the sphenoid wing is of a particular interest to the neurosurgeon because of its progressive course that can be counteracted only by a surgical intervention. The sphenoid wing agenesis is regarded as a dysplasia, which is a primary bone pathology. However, its clinical progression is related to a variety of causes, commonly the development of an intraorbital plexiform neurofibroma or the extracranial protrusion of temporal lobe parenchyma and its coverings. Thus, the cranial bone defect resulting by the primary bone dysplasia is progressively accentuated by the orbit remodeling caused by the necessity of accommodating the mass effect exerted by the growing tumor or the progression of the herniated intracranial content. The aim of this paper is to review the neurosurgical and craniofacial surgical modalities to prevent the further progression of the disease by "reconstructing" the normal relationship of the orbit and the skull.
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Legius E, Brems H. Genetic basis of neurofibromatosis type 1 and related conditions, including mosaicism. Childs Nerv Syst 2020; 36:2285-2295. [PMID: 32601904 DOI: 10.1007/s00381-020-04771-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 06/23/2020] [Indexed: 12/13/2022]
Abstract
INTRODUCTION Neurofibromatosis type 1 (NF1) is a frequent autosomal dominant disorder characterised by café-au-lait maculae (CALM), skinfold freckling, iris Lisch nodules and benign peripheral nerve sheath tumours (neurofibromas). MECHANISM The NF1 gene is a tumour suppressor gene and NF1 individuals have an increased risk for a long list of tumours, all resulting from a second hit in the normal copy of the NF1 gene. Remarkably, some non-tumour phenotypes such as CALM and pseudarthrosis are also caused by a "second hit". Germline mutations inactivating the NF1 gene show a large variability in genetic mechanisms ranging from single-nucleotide substitutions and somatic mosaicism to large deletions affecting neighbouring genes. Molecular confirmation of the clinical diagnosis is becoming increasingly more important to differentiate NF1 from other syndromes such as Legius syndrome, to investigate genotype-phenotype correlations relevant in 10% of cases and to detect somatic mosaicism. SURVEILLANCE AND THERAPY Some degree of learning difficulties, attention deficit and social problems are observed in most children and affect quality of life. There is a large individual variability in complications and the evolution of the disease is difficult to predict. Specialised outpatient clinics for children have been widely established and are important for surveillance and guidance. Regular surveillance is also important for adolescents and adults because many tumour complications can be detected by whole-body MRI and treated even before symptoms develop and irreversible damage occurs. Recent data on nodular plexiform neurofibromas with continued growth in adolescents and young adults show that many of these tumours are premalignant lesions called atypical neurofibromatous neoplasm of uncertain biological potential (ANNUBP). Specific surveillance and timely local resection of these benign peripheral nerve sheath tumours might be important to prevent malignant degeneration. In the last years, targeted therapy with MEK inhibitors has shown promise to treat unresectable and symptomatic plexiform neurofibromas. Many more challenges remain to find the best way to monitor children and adults for potential complications and to find a satisfying cure for many complications in this disorder.
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Affiliation(s)
- Eric Legius
- Department of Human Genetics, University of Leuven, Herestraat 49, 3000, Leuven, Belgium.
| | - Hilde Brems
- Department of Human Genetics, University of Leuven, Herestraat 49, 3000, Leuven, Belgium
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Assessment of nociception and related quality-of-life measures in a porcine model of neurofibromatosis type 1. Pain 2020; 160:2473-2486. [PMID: 31246731 DOI: 10.1097/j.pain.0000000000001648] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Neurofibromatosis type 1 (NF1) is an autosomal dominant genetic disorder resulting from germline mutations in the NF1 gene, which encodes neurofibromin. Patients experience a variety of symptoms, but pain in the context of NF1 remains largely underrecognized. Here, we characterize nociceptive signaling and pain behaviors in a miniswine harboring a disruptive NF1 mutation (exon 42 deletion). We present the first characterization of pain-related behaviors in a pig model of NF1, identifying unchanged agitation scores, lower tactile thresholds (allodynia), and decreased response latencies to thermal laser stimulation (hyperalgesia) in NF1 (females only) pigs. Male NF1 pigs with tumors showed reduced sleep quality and increased resting, 2 health-related quality-of-life symptoms found to be comorbid in people with NF1 pain. We explore these phenotypes in relationship to suppression of the increased activity of the N-type voltage-gated calcium (CaV2.2) channel by pharmacological antagonism of phosphorylation of a regulatory protein-the collapsin response mediator protein 2 (CRMP2), a known interactor of neurofibromin, and by targeting the interface between the α subunit of CaV2.2 and the accessory β-subunits with small molecules. Our data support the use of NF1 pigs as a large animal model for studying NF1-associated pain and for understanding the pathophysiology of NF1. Our findings demonstrate the translational potential of 2 small molecules in reversing ion channel remodeling seen in NF1. Interfering with CaV2.2, a clinically validated target for pain management, might also be a promising therapeutic strategy for NF1-related pain management.
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Oppel F, Ki DH, Zimmerman MW, Ross KN, Tao T, Shi H, He S, Aster JC, Look AT. suz12 inactivation in p53- and nf1-deficient zebrafish accelerates the onset of malignant peripheral nerve sheath tumors and expands the spectrum of tumor types. Dis Model Mech 2020; 13:dmm.042341. [PMID: 32651197 PMCID: PMC7473648 DOI: 10.1242/dmm.042341] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Accepted: 07/01/2020] [Indexed: 12/13/2022] Open
Abstract
Polycomb repressive complex 2 (PRC2) is an epigenetic regulator of gene expression that possesses histone methyltransferase activity. PRC2 trimethylates lysine 27 of histone H3 proteins (H3K27me3) as a chromatin modification associated with repressed transcription of genes frequently involved in cell proliferation or self-renewal. Loss-of-function mutations in the PRC2 core subunit SUZ12 have been identified in a variety of tumors, including malignant peripheral nerve sheath tumors (MPNSTs). To determine the consequences of SUZ12 loss in the pathogenesis of MPNST and other cancers, we used CRISPR-Cas9 to disrupt the open reading frame of each of two orthologous suz12 genes in zebrafish: suz12a and suz12b. We generated these knockout alleles in the germline of our previously described p53 (also known as tp53)- and nf1-deficient zebrafish model of MPNSTs. Loss of suz12 significantly accelerated the onset and increased the penetrance of MPNSTs compared to that in control zebrafish. Moreover, in suz12-deficient zebrafish, we detected additional types of tumors besides MPNSTs, including leukemia with histological characteristics of lymphoid malignancies, soft tissue sarcoma and pancreatic adenocarcinoma, which were not detected in p53/nf1-deficient control fish, and are also contained in the human spectrum of SUZ12-deficient malignancies identified in the AACR Genie database. The suz12-knockout tumors displayed reduced or abolished H3K27me3 epigenetic marks and upregulation of gene sets reported to be targeted by PRC2. Thus, these zebrafish lines with inactivation of suz12 in combination with loss of p53/nf1 provide a model of human MPNSTs and multiple other tumor types, which will be useful for mechanistic studies of molecular pathogenesis and targeted therapy with small molecule inhibitors. Summary: In p53- and nf1-deficient zebrafish, onset of MPNSTs, as well as diverse other tumors, is accelerated by loss of the suz12 tumor suppressor, accompanied by global reduction in H3K27me3 marks and increased Ras-Mapk signaling.
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Affiliation(s)
- Felix Oppel
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Dong H Ki
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Mark W Zimmerman
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Kenneth N Ross
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Ting Tao
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Hui Shi
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Shuning He
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Jon C Aster
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - A Thomas Look
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA
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70
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Cui XW, Ren JY, Gu YH, Li QF, Wang ZC. NF1, Neurofibromin and Gene Therapy: Prospects of Next-Generation Therapy. Curr Gene Ther 2020; 20:100-108. [PMID: 32767931 DOI: 10.2174/1566523220666200806111451] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 07/10/2020] [Accepted: 07/14/2020] [Indexed: 12/28/2022]
Abstract
Neurofibromatosis type 1 [NF1] is an autosomal dominant genetic disorder affecting multiple organs. NF1 is well known for its various clinical manifestations, including café-au-late macules, Lisch nodules, bone deformity and neurofibromas. However, there is no effective therapy for NF1. Current therapies are aimed at alleviating NF1 clinical symptoms but not curing the disease. By altering pathogenic genes, gene therapy regulates cell activities at the nucleotide level. In this review, we described the structure and functions of neurofibromin domains, including GAP-related domain [GRD], cysteine-serine rich domain [CSRD], leucine-rich domain [LRD] and C-terminal domain [CTD], which respectively alter downstream pathways. By transfecting isolated sequences of these domains, researchers can partially restore normal cell functions in neurofibroma cell lines. Furthermore, recombinant transgene sequences may be designed to encode truncated proteins, which is functional and easy to be packaged into viral vectors. In addition, the treatment effect of gene therapy is also determined by various factors such as the vectors selection, transgene packaging strategies and drug administration. We summarized multiple NF1 gene therapy strategies and discussed their feasibility from multiple angles. Different protein domains alter the function and downstream pathways of neurofibromin.
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Affiliation(s)
- Xi-Wei Cui
- Department of Plastic and Reconstructive Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200011, China
| | - Jie-Yi Ren
- Department of Plastic and Reconstructive Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200011, China
| | - Yi-Hui Gu
- Department of Plastic and Reconstructive Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200011, China
| | - Qing-Feng Li
- Department of Plastic and Reconstructive Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200011, China
| | - Zhi-Chao Wang
- Department of Plastic and Reconstructive Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200011, China
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71
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Neurofibromatosis type 1: New developments in genetics and treatment. J Am Acad Dermatol 2020; 84:1667-1676. [PMID: 32771543 DOI: 10.1016/j.jaad.2020.07.105] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 07/26/2020] [Accepted: 07/28/2020] [Indexed: 12/12/2022]
Abstract
Neurofibromatosis type 1 is the most common neurocutaneous syndrome, with a frequency of 1 in 2500 persons. Diagnosis is paramount in the pretumor stage to provide proper anticipatory guidance for a number of neoplasms, both benign and malignant. Loss-of-function mutations in the NF1 gene result in truncated and nonfunctional production of neurofibromin, a tumor suppressor protein involved in downregulating the RAS signaling pathway. New therapeutic and preventive options include tyrosine kinase inhibitors, mTOR inhibitors, interferons, and radiofrequency therapy. This review summarizes recent updates in genetics, mutation analysis assays, and treatment options targeting aberrant genetic pathways. We also propose modified diagnostic criteria and provide an algorithm for surveillance of patients with neurofibromatosis type 1.
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72
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Congenital abnormalities of the retinal vasculature in neurofibromatosis type I. Sci Rep 2020; 10:12865. [PMID: 32733046 PMCID: PMC7393144 DOI: 10.1038/s41598-020-69852-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 07/21/2020] [Indexed: 11/08/2022] Open
Abstract
The aim of this cross-sectional study was to investigate congenital abnormalities of the retinal vasculature (CARVs) in patients with neurofibromatosis type I (NF-1). Forty-eight patients (96 eyes) with NF-1 diagnosed according to the National Institutes of Health (NIH) criteria and 48 healthy controls were included in this study. Standard fundus photographs were obtained for each subject to evaluate the presence and frequency of CARVs. The sensitivity, specificity, and diagnostic accuracy of different cut-off numbers of CARVs were compared with those of the NIH criteria. Forty-four (91.7%) patients in the NF-1 group demonstrated either supranumeraty optic disc vessels or triple branching of the retinal vasculature, and 22 patients (45.8%) demonstrated both findings. The frequencies of these two CARVs were significantly different between the two groups (p < 0.00001). A cut-off value of either one for supranumerary optic disc vessels or triple branching showed the highest accuracy along with sensitivity and specificity of 91.7% and 87.5%. CARVs such as supranumerary optic disc vessels or triple branching were frequently observed in NF-1 patients, and their occurrence was unrelated to the age of patients. Thus, these CARVs could be added as new ophthalmologic manifestions for NF-1 and may potentially enable early diagnosis of NF-1.
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73
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Mund JA, Park S, Smith AE, He Y, Jiang L, Hawley E, Roberson MJ, Mitchell DK, Abu-Sultanah M, Yuan J, Bessler WK, Sandusky G, Chen S, Zhang C, Rhodes SD, Clapp DW. Genetic disruption of the small GTPase RAC1 prevents plexiform neurofibroma formation in mice with neurofibromatosis type 1. J Biol Chem 2020; 295:9948-9958. [PMID: 32471868 PMCID: PMC7380178 DOI: 10.1074/jbc.ra119.010981] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 05/27/2020] [Indexed: 12/13/2022] Open
Abstract
Neurofibromatosis type 1 (NF1) is a common cancer predisposition syndrome caused by mutations in the NF1 tumor suppressor gene. NF1 encodes neurofibromin, a GTPase-activating protein for RAS proto-oncogene GTPase (RAS). Plexiform neurofibromas are a hallmark of NF1 and result from loss of heterozygosity of NF1 in Schwann cells, leading to constitutively activated p21RAS. Given the inability to target p21RAS directly, here we performed an shRNA library screen of all human kinases and Rho-GTPases in a patient-derived NF1-/- Schwann cell line to identify novel therapeutic targets to disrupt PN formation and progression. Rho family members, including Rac family small GTPase 1 (RAC1), were identified as candidates. Corroborating these findings, we observed that shRNA-mediated knockdown of RAC1 reduces cell proliferation and phosphorylation of extracellular signal-regulated kinase (ERK) in NF1-/- Schwann cells. Genetically engineered Nf1flox/flox;PostnCre+ mice, which develop multiple PNs, also exhibited increased RAC1-GTP and phospho-ERK levels compared with Nf1flox/flox;PostnCre- littermates. Notably, mice in which both Nf1 and Rac1 loci were disrupted (Nf1flox/floxRac1flox/flox;PostnCre+) were completely free of tumors and had normal phospho-ERK activity compared with Nf1flox/flox ;PostnCre+ mice. We conclude that the RAC1-GTPase is a key downstream node of RAS and that genetic disruption of the Rac1 allele completely prevents PN tumor formation in vivo in mice.
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Affiliation(s)
- Julie A Mund
- Department of Pediatrics, Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana
| | - SuJung Park
- Department of Pediatrics, Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana
| | - Abbi E Smith
- Department of Pediatrics, Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana
| | - Yongzheng He
- Department of Pediatrics, Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana
| | - Li Jiang
- Department of Pediatrics, Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana
| | - Eric Hawley
- Department of Pediatrics, Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Michelle J Roberson
- Department of Pediatrics, Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana
| | - Dana K Mitchell
- Department of Pediatrics, Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana
| | - Mohannad Abu-Sultanah
- Department of Pediatrics, Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana
| | - Jin Yuan
- Department of Pediatrics, Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana
| | - Waylan K Bessler
- Department of Pediatrics, Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana
| | - George Sandusky
- Division of Pediatric Hematology-Oncology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Shi Chen
- Department of Pediatrics, Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana
| | - Chi Zhang
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana
| | - Steven D Rhodes
- Department of Pediatrics, Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana
- Department of Pathology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - D Wade Clapp
- Department of Pediatrics, Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana
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74
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Binobaid L, Masternak MM. Molecular targets for NF1-associated malignant peripheral nerve sheath tumor. Rep Pract Oncol Radiother 2020; 25:556-561. [PMID: 32494228 PMCID: PMC7256061 DOI: 10.1016/j.rpor.2020.04.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 04/01/2020] [Accepted: 04/15/2020] [Indexed: 10/24/2022] Open
Abstract
Malignant Peripheral Nerve Sheath Tumor (MPNST) is a soft-tissue neurosarcoma. It can occur sporadically, after radiotherapy or in patients with Neurofibromatosis 1 (NF1). The hereditary disorder, NF1, is a common cancer predisposition syndrome. The main genetic feature is the mutation of the NF1 tumor suppressor gene that is inherited in an autosomal dominant, progressive manner. Mutations of the NF1 gene increase the activity of Ras signaling and cause the development of different types of tumors, including subcutaneous and plexiform neurofibromas. These can have further mutations that mediate the transformation into MPNST. Somatic mutations that have been observed are the loss of cell cycle regulators of the CDKN2A gene, and the inactivation of Polycomb Repressive Complex 2 (PRC2), mainly embryonic ectoderm development (EED) or suppressor of zeste 12 homologue (SUZ12). Other molecular pathways that have been targeted for treatment are dual MAPK-mTOR targeting, p53 protein, and MEK-ERK pathway. To advance the therapies focused on delaying or inhibiting malignant tumor formation in NF1, we need to understand the implications of the molecular and genetic pathway that are involved in the transformation into MPNST.
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Affiliation(s)
- Lama Binobaid
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida. 6900 Lake Nona Blvd., Orlando, FL 32827, US
| | - Michal M. Masternak
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida. 6900 Lake Nona Blvd., Orlando, FL 32827, US
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75
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Gross AM, Widemann BC. Clinical trial design in neurofibromatosis type 1 as a model for other tumor predisposition syndromes. Neurooncol Adv 2020; 2:i134-i140. [PMID: 32642739 DOI: 10.1093/noajnl/vdaa017] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Up to 10% of all pediatric cancer patients may have an underlying germline mutation which predisposed them to develop a malignancy. With more patients being tested for and diagnosed with genetic tumor predisposition syndromes, there has been improved characterization of their many nonmalignant manifestations. However, designing and implementing clinical trials to treat the nonmalignant tumor and non-tumor manifestations of these syndromes poses many unique challenges. Unlike trials for malignancies where tumor response and survival can be used as straightforward trial endpoints, the nonmalignant manifestations are often chronic, evolve more slowly over time, and may not be immediately life-threatening. Therefore, they will likely require a different approach to both testing and treatment with a focus on more functional and patient-reported outcome trial endpoints. The recent success of treatment trials for the benign tumors plexiform neurofibromas in the tumor predisposition syndrome neurofibromatosis type 1 (NF1) can be used as a model for the development of clinical trials in other tumor predisposition syndromes. In this article, we review the unique challenges associated with targeting the nonmalignant aspects of these conditions as well as some of the lessons learned from the NF1 experience which may be applied to other syndromes in the future.
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Affiliation(s)
- Andrea M Gross
- Pediatric Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Brigitte C Widemann
- Pediatric Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
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Abstract
Inherited syndromes are important to recognize in the setting of a pancreatic neuroendocrine tumor (PNET) as there are significant implications for the patient's medical management and opportunity for early detection of subsequent manifestations. Although most PNETs are sporadic, approximately 10% are due to an inherited syndrome, which include multiple endocrine neoplasia type 1 (MEN1), multiple endocrine neoplasia type 4 (MEN4), von Hippel-Lindau disease (VHL), neurofibromatosis type 1 (NF1), and tuberous sclerosis complex (TSC). The general hallmarks of a hereditary endocrine neoplasia predisposition syndrome include any one of the following: multiple primary tumors (in the same or different organs), rare tumors (prevalence of less than 1 in 1,000 people in the general population), earlier age of diagnosis (usually under the age of 40), characteristic pattern of disease in the individual or family (phenotype and inheritance pattern). These syndromes are monogenic (due to a single gene disorder), highly penetrant (with all carriers of the disease exhibiting at least part of the phenotype) and can display variable expressivity (where affected individuals may have different presentations and features of the disease). A thoughtful approach to management is required, even if the presenting symptom is resolved, as these syndromes often involve multi-organ disease with a lifelong risk for tumor development. Additionally, the natural history of tumors in the setting of a hereditary condition may be different than would be expected in a sporadic form of the disease. For example, in some circumstances the risk of metastatic disease is lower, and therefor longer observation is the preferred approach over early surgical intervention. The unique aspects to management, challenges in hereditary disease recognition and accurate diagnosis, and rarity of these syndromes are all reasons to support referral to high-volume centers with the experience and knowledge to treat patients with hereditary endocrine neoplasia syndromes.
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Affiliation(s)
- Jennifer L Geurts
- Department of Surgery, Medical College of Wisconsin, Milwaukee, WI, USA
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77
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Jeong JW, Jeon S, Yu TY, Kim HS, Cho CG. An Extraordinary Case of Pheochromocytoma with Breast Cancer in a Patient with Neurofibromatosis Type 1. Chonnam Med J 2020; 56:154-155. [PMID: 32509566 PMCID: PMC7250663 DOI: 10.4068/cmj.2020.56.2.154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 12/31/2019] [Accepted: 01/14/2020] [Indexed: 11/22/2022] Open
Affiliation(s)
- Jin Woo Jeong
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Iksan, Korea
| | - Sunil Jeon
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Iksan, Korea
| | - Tae Yang Yu
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Iksan, Korea
| | - Hun Soo Kim
- Department of Pathology, Wonkwang University School of Medicine, Iksan, Korea
| | - Chung Gu Cho
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Iksan, Korea
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78
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Obo T, Koriyama N, Tokito A, Ogiso K, Nishio Y. Neurofibromatosis type 1 associated with hypophosphatemic osteomalacia due to hypersecretion of fibroblast growth factor 23: a case report. J Med Case Rep 2020; 14:56. [PMID: 32384911 PMCID: PMC7210688 DOI: 10.1186/s13256-020-02381-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 03/25/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Neurofibromatosis type 1 is characterized by multiple café au lait spots and cutaneous and plexiform neurofibromas, and is one of the most common autosomal dominant hereditary disorders caused by mutations of the neurofibromatosis type 1 tumor suppressor gene. Osteomalacia in neurofibromatosis type 1 is very rare and is characterized by later onset in adulthood. In humans, fibroblast growth factor 23, which is a causative factor of tumor-induced osteomalacia, is not only a paracrine and autocrine factor, but is also a physiological regulator of phosphate balance in normal serum. CASE PRESENTATION Our patient was a 65-year-old Japanese woman whose neurofibromas began to appear when she was in elementary school. At age 28, she was diagnosed as having neurofibromatosis type 1. A spinal compression fracture and multiple rib fractures were identified in 2012 and 2017, respectively. Her laboratory findings revealed hypophosphatemia due to renal phosphate wasting and a high serum level of fibroblast growth factor 23. Neurofibromas located on the surface of her right forearm and left upper arm, in which a slight abnormal accumulation of tracers was observed on 111indium-pentetreotide scintigraphy, were surgically removed, but there was no improvement in hypophosphatemia or serum fibroblast growth factor 23 after surgery. Therefore, we administered eldecalcitol, which also failed to produce improvement in abnormal data. Subsequent combination with dibasic calcium phosphate hydrate led to improvement in some of the abnormalities, including hypophosphatemia. Immunohistochemical staining using anti-human fibroblast growth factor 23 antibody revealed slightly positive results, however, only one out of three amplifications of the fibroblast growth factor 23 gene was observed by real-time polymerase chain reaction, and no clear fibroblast growth factor 23 gene expression in the resected neurofibromas could be confirmed. CONCLUSIONS We here describe a first rare case of a 65-year-old woman with neurofibromatosis type 1 associated with hypophosphatemic osteomalacia in which a high serum fibroblast growth factor 23 level was confirmed.
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Affiliation(s)
- Takahiko Obo
- Department of Diabetes and Endocrine Medicine, National Hospital Organization Kagoshima Medical Center, 8-1 Shiroyama-cho, Kagoshima, 892-0853, Japan.,Department of Diabetes and Endocrine Medicine, Kagoshima University Graduate School of Medicine and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima, 890-8520, Japan
| | - Nobuyuki Koriyama
- Department of Diabetes and Endocrine Medicine, National Hospital Organization Kagoshima Medical Center, 8-1 Shiroyama-cho, Kagoshima, 892-0853, Japan.
| | - Akinori Tokito
- Department of Diabetes and Endocrine Medicine, National Hospital Organization Kagoshima Medical Center, 8-1 Shiroyama-cho, Kagoshima, 892-0853, Japan
| | - Kazuma Ogiso
- Department of Diabetes and Endocrine Medicine, National Hospital Organization Kagoshima Medical Center, 8-1 Shiroyama-cho, Kagoshima, 892-0853, Japan.,Department of Diabetes and Endocrine Medicine, Kagoshima University Graduate School of Medicine and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima, 890-8520, Japan
| | - Yoshihiko Nishio
- Department of Diabetes and Endocrine Medicine, Kagoshima University Graduate School of Medicine and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima, 890-8520, Japan
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79
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Biotteau M, Déjean S, Lelong S, Iannuzzi S, Faure-Marie N, Castelnau P, Rivier F, Lauwers-Cancès V, Baudou E, Chaix Y. Sporadic and Familial Variants in NF1: An Explanation of the Wide Variability in Neurocognitive Phenotype? Front Neurol 2020; 11:368. [PMID: 32431664 PMCID: PMC7214842 DOI: 10.3389/fneur.2020.00368] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 04/14/2020] [Indexed: 12/15/2022] Open
Abstract
Background: Cognitive impairment is the most common neurological manifestation in NF1 and occurs in 30–70% of NF1 cases. The onset and severity of each specific cognitive deficit varies greatly from child to child, with no apparent external causes. The wide variability of phenotype is the most complex aspect in terms of management and care. Despite multiple research, the mechanism underlying the high heterogeneity in NF1 has not yet been elucidated. While many studies have focused on the effects of specific and precise genetic mutations on the NF1 phenotype, little has been done on the impact of NF1 transmission (sporadic vs. familial cases). We used a complete neuropsychological evaluation designed to assess five large cognitive areas: general cognitive functions (WISC-IV and EVIP); reading skills (“L'Alouette,” ODEDYS-2 and Lobrot French reading tests); phonological process (ODEDYS-2 test); visual perceptual skills (JLO, Thurstone and Corsi block tests) and attention (CPT-II), as well as psychosocial adjustments (CBCL) to explore the impact of NF1 transmission on cognitive disease manifestation in 96 children affected by NF1 [55 sporadic cases (29♀, 26♂); 41 familial cases (24♀, 17♂)]. Results: Familial and Sporadic form of NF1 only differ in IQ expression. The families' socioeconomic status (SES) impacts IQ performance but not differently between sporadic and familial variants. However, SES is lower in familial variants than in the sporadic variant of NF1. No other cognitive differences emerge between sporadic and familial NF1. Conclusions: Inheritance in NF1 failed to explain the phenotype variability in its entirety. IQ differences between groups seems in part linked to the environment where the child grows up. Children with NF1, and especially those that have early diagnoses (most often in inherited cases), must obtain careful monitoring from their early childhood, at home to strengthen investment in education and in school to early detect emerging academic problems and to quickly place them into care. Trial Registration: IDRCB, IDRCB2008-A01444-51. Registered 19 January 2009.
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Affiliation(s)
- Maëlle Biotteau
- ToNIC, Toulouse NeuroImaging Center, University of Toulouse, Inserm, UPS, Toulouse, France.,Children's Hospital, Toulouse-Purpan University Hospital, Toulouse, France
| | - Sébastien Déjean
- Institut de Mathématiques de Toulouse, UMR5219 Université de Toulouse, CNRS UPS, Toulouse, France
| | - Sandrine Lelong
- Children's Hospital, Toulouse-Purpan University Hospital, Toulouse, France
| | - Stéphanie Iannuzzi
- Children's Hospital, Toulouse-Purpan University Hospital, Toulouse, France
| | | | - Pierre Castelnau
- UMR 1253, iBrain, University of Tours, INSERM, Tours, France.,Department of Medicine, University of Tours Francois Rabelais, Tours, France.,Pediatric Neurology, Clocheville Children's Hospital, Tours University Hospital, Tours, France
| | - François Rivier
- Department of Pediatric Neurology and Reference Center for Language Disabilities, CHU Montpellier, PhyMedExp, University of Montpellier, INSERM, CNRS, Montpellier, France
| | | | - Eloïse Baudou
- ToNIC, Toulouse NeuroImaging Center, University of Toulouse, Inserm, UPS, Toulouse, France.,Children's Hospital, Toulouse-Purpan University Hospital, Toulouse, France
| | - Yves Chaix
- ToNIC, Toulouse NeuroImaging Center, University of Toulouse, Inserm, UPS, Toulouse, France.,Children's Hospital, Toulouse-Purpan University Hospital, Toulouse, France
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80
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Lalor L, Davies OMT, Basel D, Siegel DH. Café au lait spots: When and how to pursue their genetic origins. Clin Dermatol 2020; 38:421-431. [PMID: 32972601 DOI: 10.1016/j.clindermatol.2020.03.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Café au lait spots are common birthmarks seen sporadically and in association with several genetic syndromes. Dermatologists are often asked to evaluate these birthmarks both by other physicians and by parents. In some cases, it is challenging to know when and how to pursue further evaluation. Diagnostic challenges may come in the form of the appearance of the individual lesions, areas and patterns of cutaneous involvement, and associated features (or lack thereof). In this review, we aim to clarify when and how to evaluate the child with multiple or patterned café au lait spots and to explain some emerging concepts in our understanding of the genetics of these lesions.
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Affiliation(s)
- Leah Lalor
- Department of Dermatology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.
| | - Olivia M T Davies
- Department of Dermatology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Donald Basel
- Division of Genetics, Department of Pediatrics, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Dawn H Siegel
- Department of Dermatology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
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81
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Grade V Thoracic Spondylolisthesis in Neurofibromatosis Type 1: Case Report and Literature Review. World Neurosurg 2020; 138:291-296. [PMID: 32201295 DOI: 10.1016/j.wneu.2020.03.075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 03/11/2020] [Accepted: 03/12/2020] [Indexed: 11/23/2022]
Abstract
BACKGROUND Grade V thoracic spondylolisthesis secondary to neurofibromatosis type 1 (NF-1), especially combined with vertebral fusion, is rare. We reported a case of a 26-year-old female diagnosed with grade V T2spondylolisthesis and T2-T5 autofusion secondary to NF-1, which caused severe kyphotic deformity and neurologic deficits, and she was treated with posterior decompression, internal fixation, and fusion. CASE DESCRIPTION The right-handed patient admitted to the clinic due to weakness of her legs. An eye examination documented a sign of Lisch nodules in the iris. Café-au-lait macules, dermal neurofibroma of multiple forms, and rubbery bumps of varying sizes could be observed on her skin. Paresis with muscle strength of 2/5 in both lower extremities with increased muscle tone and decreased muscle mass could be observed. Radiographic results indicated grade V thoracic spondylolisthesis with vertebral fusion from T2-T5 level. To alleviate neurologic dysfunction, posterior decompression, internal fixation, and fusion were performed. She reported marked improvement in lower limb motor and sensory functions during the follow-up, and her muscle strength recovered to 5/5. CONCLUSIONS Grade V thoracic spondylolisthesis combined with vertebral fusion on T2-T5 level in NF-1 is rare. Early surgical intervention of posterior spinal decompression with internal fixation and fusion yielded satisfactory clinical outcomes.
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82
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Ravindran DM, Ravi S, Santhanakrishnan M, Sk B. LASER Assisted Excision of Solitary Neurofibroma in the Gingiva. Cureus 2020; 12:e7118. [PMID: 32257664 PMCID: PMC7105066 DOI: 10.7759/cureus.7118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Neurofibromatosis (NF) is a genetic disorder that presents as benign tumours of the nervous system originating from the nerve sheath. It is of three types: Type I, Type II and Schwannomatosis. Type I Neurofibromatosis or von Recklinghausen's disease is the most common type of neurofibromatosis seen and it accounts for 90% of all cases seen. It can be seen as light brown pigmentation spots (Café-au-lait) on the skin and multiple small tumours among the nerves. Oral manifestations of NF are very rare and can be seen as sessile lesion in the tongue or the gingiva. The major complaints of the oral manifestations include difficulty in speech and mastication which it results in progression of periodontal disease. Here, we present a case report of Type I NF which presented as a sessile lesion in the right maxillary gingiva, for which we performed an excisional biopsy using LASER.
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Affiliation(s)
- Deepak M Ravindran
- Periodontology, Sri Ramachandra Institute of Higher Education and Research, Chennai, IND
| | - Shravanthy Ravi
- Periodontology, Sri Ramachandra Institute of Higher Education and Research, Chennai, IND
| | | | - Balaji Sk
- Periodontology, Sri Ramachandra Institute of Higher Education and Research, Chennai, IND
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83
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Harrell Stewart DR, Clark GJ. Pumping the brakes on RAS - negative regulators and death effectors of RAS. J Cell Sci 2020; 133:133/3/jcs238865. [PMID: 32041893 DOI: 10.1242/jcs.238865] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Mutations that activate the RAS oncoproteins are common in cancer. However, aberrant upregulation of RAS activity often occurs in the absence of activating mutations in the RAS genes due to defects in RAS regulators. It is now clear that loss of function of Ras GTPase-activating proteins (RasGAPs) is common in tumors, and germline mutations in certain RasGAP genes are responsible for some clinical syndromes. Although regulation of RAS is central to their activity, RasGAPs exhibit great diversity in their binding partners and therefore affect signaling by multiple mechanisms that are independent of RAS. The RASSF family of tumor suppressors are essential to RAS-induced apoptosis and senescence, and constitute a barrier to RAS-mediated transformation. Suppression of RASSF protein expression can also promote the development of excessive RAS signaling by uncoupling RAS from growth inhibitory pathways. Here, we will examine how these effectors of RAS contribute to tumor suppression, through both RAS-dependent and RAS-independent mechanisms.
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Affiliation(s)
- Desmond R Harrell Stewart
- Department of Pharmacology & Toxicology, University of Louisville School of Medicine, Louisville, KY 40222, USA
| | - Geoffrey J Clark
- Department of Pharmacology & Toxicology, University of Louisville School of Medicine, Louisville, KY 40222, USA
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84
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Ehara Y, Koga M, Imafuku S, Yamamoto O, Yoshida Y. Distribution of diffuse plexiform neurofibroma on the body surface in patients with neurofibromatosis 1. J Dermatol 2019; 47:190-192. [PMID: 31849109 DOI: 10.1111/1346-8138.15194] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Accepted: 11/18/2019] [Indexed: 01/10/2023]
Abstract
Neurofibromatosis 1 (NF1) is a genetic disease characterized by cutaneous, neurological and osseous abnormalities. Approximately 20% of patients develop plexiform neurofibroma (PN), resulting in impaired quality of life. To evaluate distribution of diffuse PN on the body surface, a retrospective study was conducted for 354 patients with NF1 from 2007 to 2018 in Japan. We investigated a total of 40 patients with clinically apparent superficial diffuse PN. In the cases evaluated, 57.4% of the diffuse PN were located on the trunk, 19.2% the head and neck, 12.8% the lower limbs and 10.6% the upper limbs. Remarkably, 75.0% of the diffuse PN were located on the dorsal side. The frequency was significantly higher on the trunk than on the head and neck (P = 0.026). Our findings provide useful information for giving attention to the high possibility of diffuse PN on the dorsal side before progression in childhood and for future treatment in NF1.
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Affiliation(s)
- Yuko Ehara
- Division of Dermatology, Department of Medicine of Sensory and Motor Organs, Faculty of Medicine, Tottori University, Yonago, Japan
| | - Monji Koga
- Department of Dermatology, Fukuoka University School of Medicine, Fukuoka, Japan
| | - Shinichi Imafuku
- Department of Dermatology, Fukuoka University School of Medicine, Fukuoka, Japan
| | - Osamu Yamamoto
- Division of Dermatology, Department of Medicine of Sensory and Motor Organs, Faculty of Medicine, Tottori University, Yonago, Japan
| | - Yuichi Yoshida
- Division of Dermatology, Department of Medicine of Sensory and Motor Organs, Faculty of Medicine, Tottori University, Yonago, Japan
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85
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Pinna V, Daniele P, Calcagni G, Mariniello L, Criscione R, Giardina C, Lepri FR, Hozhabri H, Alberico A, Cavone S, Morella AT, Mandile R, Annunziata F, Di Giosaffatte N, D'Asdia MC, Versacci P, Capolino R, Strisciuglio P, Giustini S, Melis D, Digilio MC, Tartaglia M, Marino B, De Luca A. Prevalence, Type, and Molecular Spectrum of NF1 Mutations in Patients with Neurofibromatosis Type 1 and Congenital Heart Disease. Genes (Basel) 2019; 10:E675. [PMID: 31487937 PMCID: PMC6770533 DOI: 10.3390/genes10090675] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2019] [Revised: 08/30/2019] [Accepted: 09/01/2019] [Indexed: 02/05/2023] Open
Abstract
The aim of this study was to assess the prevalence and type of congenital heart disease (CHD) and the associated mutation spectrum in a large series of patients with neurofibromatosis type 1 (NF1), and correlate the mutation type with the presence and subgroups of cardiac defects. The study cohort included 493 individuals with molecularly confirmed diagnosis of NF1 for whom cardiac evaluation data were available. CHD was reported in 62/493 (12.6%) patients. Among these patients, 23/62 (37.1%) had pulmonary valve stenosis/dysplasia, 20/62 (32.3%) had mitral valve anomalies, and 10/62 (16.1%) had septal defects. Other defects occurred as rare events. In this NF1 subcohort, three subjects carried a whole-gene deletion, while 59 were heterozygous for an intragenic mutation. A significantly increased prevalence of non-truncating intragenic mutations was either observed in individuals with CHD (22/59, 37.3%) or with pulmonary valve stenosis (13/20, 65.0%), when compared to individuals without CHD (89/420, 21.2%) (p = 0.038) or pulmonary valve stenosis (98/459, 21.4%) (p = 0.002). Similarly, patients with non-truncating NF1 mutations displayed two- and six-fold higher risk of developing CHD (odds ratio = 1.9713, 95% confidence interval (CI): 1.1162-3.4814, p = 0.0193) and pulmonary valve stenosis (odds ratio = 6.8411, 95% CI: 2.6574-17.6114, p = 0.0001), respectively. Noteworthy, all but one patient (19/20, 95.0%) with pulmonary valve stenosis, and 18/35 (51.4%) patients with other CHDs displayed Noonan syndrome (NS)-like features. Present data confirm the significant frequency of CHD in patients with NF1, and provide further evidence for a higher than expected prevalence of NF1 in-frame variants and NS-like characteristics in NF1 patients with CHD, particularly with pulmonary valve stenosis.
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Affiliation(s)
- Valentina Pinna
- UOS Diagnosi Genetica Molecolare, Fondazione IRCCS Casa Sollievo della Sofferenza, 71013 San Giovanni Rotondo (FG), Italy.
| | - Paola Daniele
- UOS Diagnosi Genetica Molecolare, Fondazione IRCCS Casa Sollievo della Sofferenza, 71013 San Giovanni Rotondo (FG), Italy.
| | - Giulio Calcagni
- Department of Pediatric Cardiology and Cardiac Surgery, Bambino Gesù Pediatric Hospital and Research Institute, 00165 Rome, Italy.
| | - Lucio Mariniello
- Department of Translational Medical Science, Section of Pediatrics, Federico II University, 80100 Naples, Italy.
| | - Roberta Criscione
- UOS Diagnosi Genetica Molecolare, Fondazione IRCCS Casa Sollievo della Sofferenza, 71013 San Giovanni Rotondo (FG), Italy.
- Department of Pediatrics, Sapienza University of Rome, 00161 Rome, Italy.
| | - Chiara Giardina
- UOS Diagnosi Genetica Molecolare, Fondazione IRCCS Casa Sollievo della Sofferenza, 71013 San Giovanni Rotondo (FG), Italy.
- Department of Pediatrics, Sapienza University of Rome, 00161 Rome, Italy.
| | - Francesca Romana Lepri
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, 00146 Rome, Italy.
| | - Hossein Hozhabri
- UOS Diagnosi Genetica Molecolare, Fondazione IRCCS Casa Sollievo della Sofferenza, 71013 San Giovanni Rotondo (FG), Italy.
| | - Angela Alberico
- UOS Diagnosi Genetica Molecolare, Fondazione IRCCS Casa Sollievo della Sofferenza, 71013 San Giovanni Rotondo (FG), Italy.
| | - Stefania Cavone
- UOS Diagnosi Genetica Molecolare, Fondazione IRCCS Casa Sollievo della Sofferenza, 71013 San Giovanni Rotondo (FG), Italy.
| | - Annunziata Tina Morella
- UOS Diagnosi Genetica Molecolare, Fondazione IRCCS Casa Sollievo della Sofferenza, 71013 San Giovanni Rotondo (FG), Italy.
| | - Roberta Mandile
- Department of Translational Medical Science, Section of Pediatrics, Federico II University, 80100 Naples, Italy.
| | - Francesca Annunziata
- UOS Diagnosi Genetica Molecolare, Fondazione IRCCS Casa Sollievo della Sofferenza, 71013 San Giovanni Rotondo (FG), Italy.
| | - Niccolò Di Giosaffatte
- UOS Diagnosi Genetica Molecolare, Fondazione IRCCS Casa Sollievo della Sofferenza, 71013 San Giovanni Rotondo (FG), Italy.
| | - Maria Cecilia D'Asdia
- UOS Diagnosi Genetica Molecolare, Fondazione IRCCS Casa Sollievo della Sofferenza, 71013 San Giovanni Rotondo (FG), Italy.
| | - Paolo Versacci
- Department of Pediatrics, Sapienza University of Rome, 00161 Rome, Italy.
| | - Rossella Capolino
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, 00146 Rome, Italy.
| | - Pietro Strisciuglio
- Department of Translational Medical Science, Section of Pediatrics, Federico II University, 80100 Naples, Italy.
| | - Sandra Giustini
- Department of Dermatology and Venereology, Sapienza University of Rome, Policlinico Umberto I, 00161 Rome, Italy.
| | - Daniela Melis
- Department of Translational Medical Science, Section of Pediatrics, Federico II University, 80100 Naples, Italy.
| | - Maria Cristina Digilio
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, 00146 Rome, Italy.
| | - Marco Tartaglia
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, 00146 Rome, Italy.
| | - Bruno Marino
- Department of Pediatrics, Sapienza University of Rome, 00161 Rome, Italy
| | - Alessandro De Luca
- UOS Diagnosi Genetica Molecolare, Fondazione IRCCS Casa Sollievo della Sofferenza, 71013 San Giovanni Rotondo (FG), Italy.
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86
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Hereditary myeloid malignancies. Best Pract Res Clin Haematol 2019; 32:163-176. [DOI: 10.1016/j.beha.2019.05.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 05/01/2019] [Indexed: 12/18/2022]
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87
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Raffalli-Ebezant H, George K, Burkitt-Wright E, Roncaroli F, Evans G, Soh C, Ealing J, Vassallo G, Elloo J, Karabatsou K. Neurosurgical contribution within a complex NF1 supraregional service. Clin Neurol Neurosurg 2019; 180:18-24. [DOI: 10.1016/j.clineuro.2019.03.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2019] [Revised: 02/25/2019] [Accepted: 03/03/2019] [Indexed: 01/19/2023]
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88
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Scheffzek K, Shivalingaiah G. Ras-Specific GTPase-Activating Proteins-Structures, Mechanisms, and Interactions. Cold Spring Harb Perspect Med 2019; 9:cshperspect.a031500. [PMID: 30104198 DOI: 10.1101/cshperspect.a031500] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Ras-specific GTPase-activating proteins (RasGAPs) down-regulate the biological activity of Ras proteins by accelerating their intrinsic rate of GTP hydrolysis, basically by a transition state stabilizing mechanism. Oncogenic Ras is commonly not sensitive to RasGAPs caused by interference of mutants with the electronic or steric requirements of the transition state, resulting in up-regulation of activated Ras in respective cells. RasGAPs are modular proteins containing a helical catalytic RasGAP module surrounded by smaller domains that are frequently involved in the subcellular localization or contributing to regulatory features of their host proteins. In this review, we summarize current knowledge about RasGAP structure, mechanism, regulation, and dual-substrate specificity and discuss in some detail neurofibromin, one of the most important negative Ras regulators in cellular growth control and neuronal function.
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Affiliation(s)
- Klaus Scheffzek
- Division of Biological Chemistry (Biocenter), Medical University of Innsbruck, A-6020 Innsbruck, Austria
| | - Giridhar Shivalingaiah
- Division of Biological Chemistry (Biocenter), Medical University of Innsbruck, A-6020 Innsbruck, Austria
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89
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Home practice and quality of life among patients with neurofibromatosis randomized to a mind-body intervention. Complement Ther Med 2019; 42:114-118. [DOI: 10.1016/j.ctim.2018.10.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 10/18/2018] [Accepted: 10/19/2018] [Indexed: 01/17/2023] Open
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90
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Ptáček LJ. Raymond Leslie White (1943–2018). Am J Hum Genet 2019. [DOI: 10.1016/j.ajhg.2018.11.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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91
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Vranceanu AM, Zale EL, Funes CJ, Macklin EA, McCurley J, Park ER, Jordan JT, Lin A, Plotkin SR. Mind-Body Treatment for International English-Speaking Adults With Neurofibromatosis via Live Videoconferencing: Protocol for a Single-Blind Randomized Controlled Trial. JMIR Res Protoc 2018; 7:e11008. [PMID: 30355560 PMCID: PMC6231775 DOI: 10.2196/11008] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 07/05/2018] [Accepted: 07/06/2018] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Neurofibromatoses (NF) are rare genetic conditions associated with substantial psychosocial burden and impaired quality of life (QoL). We developed the first NF-tailored mind-body program (the Relaxation Response Resiliency Program for NF) and adapted it for delivery via live videoconferencing to decrease participation barriers and increase its reach. In a pilot randomized controlled trial (RCT), we found that the Relaxation Response Resiliency Program for NF had excellent feasibility and acceptability when delivered via live videoconferencing; furthermore, the Relaxation Response Resiliency Program for NF showed proof of concept in improving QoL compared with an NF-tailored health education control program (the Health Enhancement Program for NF). A fully powered trial is needed to ascertain the efficacy and durability of the Relaxation Response Resiliency Program for NF delivered via secure live videoconferencing among geographically diverse patients. OBJECTIVE The objective of this study is to evaluate the efficacy of the Relaxation Response Resiliency Program for NF versus the Health Enhancement Program for NF, both delivered in groups via secure live videoconferencing, among geographically diverse patients with NF across the United States and internationally. Here we describe the protocol, manualized treatments, evaluation plan, and study design. METHODS This is a single-blind RCT. Patients are told that they will be randomized to one of the two stress management programs (stress management program 1: the Relaxation Response Resiliency Program for NF and stress management program 2: the Health Enhancement Program for NF). Patients are recruited from NF-specific national and international foundations and NF clinics across the United States through study ads and a video of participants who have completed the program as part of the pilot study or ongoing trial. Interested participants are screened for eligibility via secure live videoconferencing (self-reported stress and difficulties coping, no change in antidepressant medication within the past 3 months, no psychotherapy within the past 3 months, no major upcoming surgeries within the next 12 months, English speaking, and able to complete questionnaires online and participate in live video interventions) and consent obtained before participation. Both programs are manualized comprising 8 sessions delivered via secure live videoconferencing by trained clinical psychologists. Primary outcomes are physical health QoL and psychological health QoL. Secondary outcomes are social relationship QoL, environment QoL, and psychosocial and resiliency variables. Outcomes are assessed at baseline, posttraining, and 6- and 12-month follow-ups. RESULTS The trial is ongoing. Thus far, we have recruited 55 patients and aim to recruit a total of 224. Recruitment will close in May 2020; we plan to complete data analyses by June 2021. CONCLUSIONS This trial will answer key questions about the efficacy and durability of the Relaxation Response Resiliency Program for NF via live videoconferencing with English-speaking adults with NF worldwide. If found efficacious, this program can be readily implemented through national and international NF foundations and NF-specific clinics. The virtual model of delivery has extensive applications for patients in rural areas, those with disability or illness that precludes travel to clinics, and those with rare diseases. TRIAL REGISTRATION ClinicalTrials.gov NCT03406208; https://clinicaltrials.gov/ct2/show/NCT03406208 (Archived by WebCite at http://www.webcitation.org/72ZoTDQ6h). INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID) RR1-10.2196/11008.
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Affiliation(s)
- Ana-Maria Vranceanu
- Integrated Brain Health Clinical and Research Program, Department of Psychiatry, Massachusetts General Hospital, Boston, MA, United States
| | - Emily L Zale
- Integrated Brain Health Clinical and Research Program, Department of Psychiatry, Massachusetts General Hospital, Boston, MA, United States
| | - Christopher J Funes
- Integrated Brain Health Clinical and Research Program, Department of Psychiatry, Massachusetts General Hospital, Boston, MA, United States
| | - Eric A Macklin
- Biostatistics Center, Department of Medicine, Massachusetts General Hospital, Boston, MA, United States
| | - Jessica McCurley
- Integrated Brain Health Clinical and Research Program, Department of Psychiatry, Massachusetts General Hospital, Boston, MA, United States
| | - Elyse R Park
- Benson Henry Institute for Mind Body Medicine, Department of Psychiatry, Massachusetts General Hospital, Boston, MA, United States
| | - Justin T Jordan
- Neurofibromatosis Clinic, Department of Neurology, Massachusetts General Hospital, Boston, MA, United States
| | - Ann Lin
- Integrated Brain Health Clinical and Research Program, Department of Psychiatry, Massachusetts General Hospital, Boston, MA, United States
| | - Scott R Plotkin
- Neurofibromatosis Clinic, Department of Neurology, Massachusetts General Hospital, Boston, MA, United States
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92
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Recent Advances in the Diagnosis and Pathogenesis of Neurofibromatosis Type 1 (NF1)-associated Peripheral Nervous System Neoplasms. Adv Anat Pathol 2018; 25:353-368. [PMID: 29762158 DOI: 10.1097/pap.0000000000000197] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The diagnosis of a neurofibroma or a malignant peripheral nerve sheath tumor (MPNST) often raises the question of whether the patient has the genetic disorder neurofibromatosis type 1 (NF1) as well as how this will impact the patient's outcome, what their risk is for developing additional neoplasms and whether treatment options differ for NF1-associated and sporadic peripheral nerve sheath tumors. Establishing a diagnosis of NF1 is challenging as this disorder has numerous neoplastic and non-neoplastic manifestations which are variably present in individual patients. Further, other genetic diseases affecting the Ras signaling cascade (RASopathies) mimic many of the clinical features of NF1. Here, we review the clinical manifestations of NF1 and compare and contrast them with those of the RASopathies. We also consider current approaches to genetic testing for germline NF1 mutations. We then focus on NF1-associated neurofibromas, considering first the complicated clinical behavior and pathology of these neoplasms and then discussing our current understanding of the genomic abnormalities that drive their pathogenesis, including the mutations encountered in atypical neurofibromas. As several neurofibroma subtypes are capable of undergoing malignant transformation to become MPNSTs, we compare and contrast patient outcomes in sporadic, NF1-associated and radiation-induced MPNSTs, and review the challenging pathology of these lesions. The mutations involved in neurofibroma-MPNST progression, including the recent identification of mutations affecting epigenetic regulators, are then considered. Finally, we explore how our current understanding of neurofibroma and MPNST pathogenesis is informing the design of new therapies for these neoplasms.
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93
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Abstract
PURPOSE OF REVIEW This article presents an up-to-date summary of the genetic etiology, diagnostic criteria, clinical features, and current management recommendations for the most common neurocutaneous disorders encountered in clinical adult and pediatric neurology practices. RECENT FINDINGS The phakomatoses are a phenotypically and genetically diverse group of multisystem disorders that primarily affect the skin and central nervous system. A greater understanding of the genetic and biological underpinnings of numerous neurocutaneous disorders has led to better clinical characterization, more refined diagnostic criteria, and improved treatments in neurofibromatosis type 1, Legius syndrome, neurofibromatosis type 2, Noonan syndrome with multiple lentigines, tuberous sclerosis complex, Sturge-Weber syndrome, and incontinentia pigmenti. SUMMARY Neurologists require a basic knowledge of and familiarity with a wide variety of neurocutaneous disorders because of the frequent involvement of the central and peripheral nervous systems. A simple routine skin examination can often open a broad differential diagnosis and lead to improved patient care.
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94
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Burger H, Bezuidenhout H, Sher-Locketz C, Baatjes K, Van Wyk J, Bonthuys A. Malignant peripheral nerve sheath tumours and neurofibromatosis 1: A case series and recommendations for care. SOUTH AFRICAN JOURNAL OF ONCOLOGY 2018. [DOI: 10.4102/sajo.v2i0.46] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Background: The incidence of malignant peripheral nerve sheath tumours (MPNST) in patients with neurofibromatosis 1 (NF1) is significantly higher than that of the general population. NF1-associated MPNST occur at a younger age and carry a worse prognosis than sporadic MPNST.Aim: This case series describes four cases of MPNST in patients with NF1.Setting: The study was performed in a public academic hospital in the Western Cape province of South Africa.Method: Demographics, disease status, histopathology, treatment and outcome data were collected retrospectively from medical charts and through review of histological slides.Results: The median age was 36.5 years. All tumours were > 5 cm at presentation and located on the trunk. One patient presented with metastatic disease. There was a mean delay of 3.5 months from presentation to initiation of treatment. Three patients underwent wide excision, with one receiving adjuvant chemotherapy and radiotherapy. At a median follow-up of 20 months from histological diagnosis only one patient was alive in clinical remission. Two patients had succumbed to progressive disease at 8 and 16 months from diagnosis and one patient with terminal metastatic disease was lost to follow-up.Conclusion: In this series the patients presented with advanced, often unresectable lesions for which single modality therapy was not curative. An adult NF1 health surveillance guideline for resource-constrained environments could lead to early diagnosis and treatment of MPNST and other complications in NF1 patients.
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95
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Tan AP, Mankad K, Gonçalves FG, Talenti G, Alexia E. Macrocephaly: Solving the Diagnostic Dilemma. Top Magn Reson Imaging 2018; 27:197-217. [PMID: 30086108 DOI: 10.1097/rmr.0000000000000170] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Macrocephaly is a relatively common clinical condition affecting up to 5% of the pediatric population. It is defined as an abnormally large head with an occipitofrontal circumference greater than 2 standard deviations above the mean for a given age and sex. Megalencephaly refers exclusively to brain overgrowth exceeding twice the standard deviation. Macrocephaly can be isolated and benign or may be the first indication of an underlying congenital, genetic, or acquired disorder, whereas megalencephaly is more often syndromic. Megalencephaly can be divided into 2 subtypes: metabolic and developmental, caused by genetic defects in cellular metabolism and alterations in signaling pathways, respectively. Neuroimaging plays an important role in the evaluation of macrocephaly, especially in the metabolic subtype which may not be overtly apparent clinically. This article outlines the diverse etiologies of macrocephaly, delineates their clinical and radiographic features, and suggests a clinicoradiological algorithm for evaluation.
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Affiliation(s)
- Ai Peng Tan
- Department of Diagnostic Radiology, National University Health System, Singapore, Singapore
| | - Kshitij Mankad
- Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom
| | | | - Giacomo Talenti
- Neuroradiology Unit, Padua University Hospital, Padua, Italy
| | - Egloff Alexia
- Perinatal Imaging and Health Department, St Thomas' Hospital, London, United Kingdom
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96
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Buffet A, Burnichon N, Amar L, Gimenez-Roqueplo AP. Pheochromocytoma: When to search a germline defect? Presse Med 2018; 47:e109-e118. [DOI: 10.1016/j.lpm.2018.07.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
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97
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White KA, Swier VJ, Cain JT, Kohlmeyer JL, Meyerholz DK, Tanas MR, Uthoff J, Hammond E, Li H, Rohret FA, Goeken A, Chan CH, Leidinger MR, Umesalma S, Wallace MR, Dodd RD, Panzer K, Tang AH, Darbro BW, Moutal A, Cai S, Li W, Bellampalli SS, Khanna R, Rogers CS, Sieren JC, Quelle DE, Weimer JM. A porcine model of neurofibromatosis type 1 that mimics the human disease. JCI Insight 2018; 3:120402. [PMID: 29925695 DOI: 10.1172/jci.insight.120402] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Accepted: 05/17/2018] [Indexed: 12/11/2022] Open
Abstract
Loss of the NF1 tumor suppressor gene causes the autosomal dominant condition, neurofibromatosis type 1 (NF1). Children and adults with NF1 suffer from pathologies including benign and malignant tumors to cognitive deficits, seizures, growth abnormalities, and peripheral neuropathies. NF1 encodes neurofibromin, a Ras-GTPase activating protein, and NF1 mutations result in hyperactivated Ras signaling in patients. Existing NF1 mutant mice mimic individual aspects of NF1, but none comprehensively models the disease. We describe a potentially novel Yucatan miniswine model bearing a heterozygotic mutation in NF1 (exon 42 deletion) orthologous to a mutation found in NF1 patients. NF1+/ex42del miniswine phenocopy the wide range of manifestations seen in NF1 patients, including café au lait spots, neurofibromas, axillary freckling, and neurological defects in learning and memory. Molecular analyses verified reduced neurofibromin expression in swine NF1+/ex42del fibroblasts, as well as hyperactivation of Ras, as measured by increased expression of its downstream effectors, phosphorylated ERK1/2, SIAH, and the checkpoint regulators p53 and p21. Consistent with altered pain signaling in NF1, dysregulation of calcium and sodium channels was observed in dorsal root ganglia expressing mutant NF1. Thus, these NF1+/ex42del miniswine recapitulate the disease and provide a unique, much-needed tool to advance the study and treatment of NF1.
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Affiliation(s)
- Katherine A White
- Pediatrics and Rare Diseases Group, Sanford Research, Sioux Falls, South Dakota, USA
| | - Vicki J Swier
- Pediatrics and Rare Diseases Group, Sanford Research, Sioux Falls, South Dakota, USA
| | - Jacob T Cain
- Pediatrics and Rare Diseases Group, Sanford Research, Sioux Falls, South Dakota, USA
| | | | | | | | - Johanna Uthoff
- Department of Radiology, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA.,Department of Biomedical Engineering at the University of Iowa, Iowa City, Iowa, USA
| | - Emily Hammond
- Department of Radiology, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA.,Department of Biomedical Engineering at the University of Iowa, Iowa City, Iowa, USA
| | - Hua Li
- Department of Molecular Genetics and Microbiology and.,University of Florida Health Cancer Center, University of Florida, Gainesville, Florida, USA
| | | | | | - Chun-Hung Chan
- Pediatrics and Rare Diseases Group, Sanford Research, Sioux Falls, South Dakota, USA
| | | | | | - Margaret R Wallace
- Department of Molecular Genetics and Microbiology and.,University of Florida Health Cancer Center, University of Florida, Gainesville, Florida, USA
| | - Rebecca D Dodd
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA.,Holden Comprehensive Cancer Center, University of Iowa, Iowa City, Iowa, USA
| | - Karin Panzer
- Department of Pediatrics, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Amy H Tang
- Department of Microbiology and Molecular Cell Biology, Leroy T. Canoles Jr. Cancer Research Center, Eastern Virginia Medical School, Norfolk, Virginia
| | - Benjamin W Darbro
- Holden Comprehensive Cancer Center, University of Iowa, Iowa City, Iowa, USA.,Department of Pediatrics, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Aubin Moutal
- Department of Pharmacology, University of Arizona, Tucson, Arizona, USA
| | - Song Cai
- Department of Pharmacology, University of Arizona, Tucson, Arizona, USA
| | - Wennan Li
- Department of Pharmacology, University of Arizona, Tucson, Arizona, USA
| | | | - Rajesh Khanna
- Department of Pharmacology, University of Arizona, Tucson, Arizona, USA
| | | | - Jessica C Sieren
- Department of Radiology, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA.,Department of Biomedical Engineering at the University of Iowa, Iowa City, Iowa, USA.,Holden Comprehensive Cancer Center, University of Iowa, Iowa City, Iowa, USA
| | - Dawn E Quelle
- Molecular Medicine Program.,Department of Pathology, and.,Department of Pharmacology and.,Holden Comprehensive Cancer Center, University of Iowa, Iowa City, Iowa, USA
| | - Jill M Weimer
- Pediatrics and Rare Diseases Group, Sanford Research, Sioux Falls, South Dakota, USA.,Department of Pediatrics, Sanford School of Medicine at the University of South Dakota, Sioux Falls, South Dakota, USA
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98
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Dard L, Bellance N, Lacombe D, Rossignol R. RAS signalling in energy metabolism and rare human diseases. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2018; 1859:845-867. [PMID: 29750912 DOI: 10.1016/j.bbabio.2018.05.003] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 04/12/2018] [Accepted: 05/03/2018] [Indexed: 02/07/2023]
Abstract
The RAS pathway is a highly conserved cascade of protein-protein interactions and phosphorylation that is at the heart of signalling networks that govern proliferation, differentiation and cell survival. Recent findings indicate that the RAS pathway plays a role in the regulation of energy metabolism via the control of mitochondrial form and function but little is known on the participation of this effect in RAS-related rare human genetic diseases. Germline mutations that hyperactivate the RAS pathway have been discovered and linked to human developmental disorders that are known as RASopathies. Individuals with RASopathies, which are estimated to affect approximately 1/1000 human birth, share many overlapping characteristics, including cardiac malformations, short stature, neurocognitive impairment, craniofacial dysmorphy, cutaneous, musculoskeletal, and ocular abnormalities, hypotonia and a predisposition to developing cancer. Since the identification of the first RASopathy, type 1 neurofibromatosis (NF1), which is caused by the inactivation of neurofibromin 1, several other syndromes have been associated with mutations in the core components of the RAS-MAPK pathway. These syndromes include Noonan syndrome (NS), Noonan syndrome with multiple lentigines (NSML), which was formerly called LEOPARD syndrome, Costello syndrome (CS), cardio-facio-cutaneous syndrome (CFC), Legius syndrome (LS) and capillary malformation-arteriovenous malformation syndrome (CM-AVM). Here, we review current knowledge about the bioenergetics of the RASopathies and discuss the molecular control of energy homeostasis and mitochondrial physiology by the RAS pathway.
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Affiliation(s)
- L Dard
- Bordeaux University, 33000 Bordeaux, France; INSERM U1211, 33000 Bordeaux, France
| | - N Bellance
- Bordeaux University, 33000 Bordeaux, France; INSERM U1211, 33000 Bordeaux, France
| | - D Lacombe
- Bordeaux University, 33000 Bordeaux, France; INSERM U1211, 33000 Bordeaux, France; CHU de Bordeaux, Service de Génétique Médicale, F-33076 Bordeaux, France
| | - R Rossignol
- Bordeaux University, 33000 Bordeaux, France; INSERM U1211, 33000 Bordeaux, France; CELLOMET, CGFB-146 Rue Léo Saignat, Bordeaux, France.
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99
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Freret ME, Gutmann DH. Insights into optic pathway glioma vision loss from mouse models of neurofibromatosis type 1. J Neurosci Res 2018; 97:45-56. [PMID: 29704429 DOI: 10.1002/jnr.24250] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 04/09/2018] [Indexed: 12/12/2022]
Abstract
Neurofibromatosis type 1 (NF1) is a common cancer predisposition syndrome caused by mutations in the NF1 gene. The NF1-encoded protein (neurofibromin) is an inhibitor of the oncoprotein RAS and controls cell growth and survival. Individuals with NF1 are prone to developing low-grade tumors of the optic nerves, chiasm, tracts, and radiations, termed optic pathway gliomas (OPGs), which can cause vision loss. A paucity of surgical tumor specimens and of patient-derived xenografts for investigative studies has limited our understanding of human NF1-associated OPG (NF1-OPG). However, mice genetically engineered to harbor Nf1 gene mutations develop optic gliomas that share many features of their human counterparts. These genetically engineered mouse (GEM) strains have provided important insights into the cellular and molecular determinants that underlie mouse Nf1 optic glioma development, maintenance, and associated vision loss, with relevance by extension to human NF1-OPG disease. Herein, we review our current understanding of NF1-OPG pathobiology and describe the mechanisms responsible for tumor initiation, growth, and associated vision loss in Nf1 GEM models. We also discuss how Nf1 GEM and other preclinical models can be deployed to identify and evaluate molecularly targeted therapies for OPG, particularly as they pertain to future strategies aimed at preventing or improving tumor-associated vision loss in children with NF1.
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Affiliation(s)
- Morgan E Freret
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri
| | - David H Gutmann
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri
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100
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Stewart DR, Korf BR, Nathanson KL, Stevenson DA, Yohay K. Care of adults with neurofibromatosis type 1: a clinical practice resource of the American College of Medical Genetics and Genomics (ACMG). Genet Med 2018; 20:671-682. [DOI: 10.1038/gim.2018.28] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 01/22/2018] [Indexed: 12/25/2022] Open
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