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1.
Gene ; 746: 144658, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32283115

RESUMO

Neurofibromatosis 1 (NF1) is an autosomal dominant disorder characterized by café-au-lait spots, intertriginous freckling, and multiple neurofibromas. Classically, it has been described that hypertrophic cardiomyopathy (HCM) may be a cardiovascular manifestation of neurofibromatosis 1, although the relationship between these two entities has not been fully established. We report a large Spanish family carrying a pathogenic truncating variant in NF1 (p.Arg2258Ter) causing neurofibromatosis 1, and a pathogenic missense variant in MYH7 (p. Arg453Cys), causing hypertrophic cardiomyopathy independently. A complete penetrance was observed in both genetic diseases, reinforcing the notion of deleterious effects of both rare variants. According to our report, hypertrophic cardiomyopathy in patients with NF1 should not be considered as part of the clinical spectrum in all cases. A careful and comprehensive assessment, including family evaluation and genetic testing for HCM should be considered as part of the diagnostic work-up in individuals presenting with both phenotypes.


Assuntos
Manchas Café com Leite/genética , Miosinas Cardíacas/genética , Cardiomiopatia Hipertrófica Familiar/genética , Códon de Terminação , Mutação de Sentido Incorreto , Cadeias Pesadas de Miosina/genética , Neurofibromatose 1/genética , Neurofibromina 1/genética , Substituição de Aminoácidos , Família , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Linhagem , Espanha
2.
PLoS One ; 15(2): e0228222, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32074109

RESUMO

Genetically modified swine disease models are becoming increasingly important for studying molecular, physiological and pathological characteristics of human disorders. Given the limited history of these model systems, there remains a great need for proven molecular reagents in swine tissue. Here, to provide a resource for neurological models of disease, we validated antibodies by immunohistochemistry for use in examining central nervous system (CNS) markers in a recently developed miniswine model of neurofibromatosis type 1 (NF1). NF1 is an autosomal dominant tumor predisposition disorder stemming from mutations in NF1, a gene that encodes the Ras-GTPase activating protein neurofibromin. Patients classically present with benign neurofibromas throughout their bodies and can also present with neurological associated symptoms such as chronic pain, cognitive impairment, and behavioral abnormalities. As validated antibodies for immunohistochemistry applications are particularly difficult to find for swine models of neurological disease, we present immunostaining validation of antibodies implicated in glial inflammation (CD68), oligodendrocyte development (NG2, O4 and Olig2), and neuron differentiation and neurotransmission (doublecortin, GAD67, and tyrosine hydroxylase) by examining cellular localization and brain region specificity. Additionally, we confirm the utility of anti-GFAP, anti-Iba1, and anti-MBP antibodies, previously validated in swine, by testing their immunoreactivity across multiple brain regions in mutant NF1 samples. These immunostaining protocols for CNS markers provide a useful resource to the scientific community, furthering the utility of genetically modified miniswine for translational and clinical applications.


Assuntos
Biomarcadores/metabolismo , Neurofibromatose 1/patologia , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Peptídeo Relacionado com Gene de Calcitonina/metabolismo , Linhagem da Célula , Modelos Animais de Doenças , Proteína Glial Fibrilar Ácida/metabolismo , Proteínas dos Microfilamentos/metabolismo , Microglia/citologia , Microglia/metabolismo , Neurofibromatose 1/metabolismo , Neurofibromina 1/genética , Fator de Transcrição 2 de Oligodendrócitos/metabolismo , Oligodendroglia/citologia , Oligodendroglia/metabolismo , Suínos
3.
Nat Commun ; 11(1): 550, 2020 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-31992716

RESUMO

Many cellular models aimed at elucidating cancer biology do not recapitulate pathobiology including tumor heterogeneity, an inherent feature of cancer that underlies treatment resistance. Here we introduce a cancer modeling paradigm using genetically engineered human pluripotent stem cells (hiPSCs) that captures authentic cancer pathobiology. Orthotopic engraftment of the neural progenitor cells derived from hiPSCs that have been genome-edited to contain tumor-associated genetic driver mutations revealed by The Cancer Genome Atlas project for glioblastoma (GBM) results in formation of high-grade gliomas. Similar to patient-derived GBM, these models harbor inter-tumor heterogeneity resembling different GBM molecular subtypes, intra-tumor heterogeneity, and extrachromosomal DNA amplification. Re-engraftment of these primary tumor neurospheres generates secondary tumors with features characteristic of patient samples and present mutation-dependent patterns of tumor evolution. These cancer avatar models provide a platform for comprehensive longitudinal assessment of human tumor development as governed by molecular subtype mutations and lineage-restricted differentiation.


Assuntos
Engenharia Genética , Glioblastoma/genética , Glioblastoma/patologia , Células-Tronco Pluripotentes/patologia , Animais , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Diferenciação Celular , Linhagem Celular Tumoral , Feminino , Regulação Neoplásica da Expressão Gênica , Genoma , Glioblastoma/metabolismo , Glioma/genética , Glioma/patologia , Humanos , Camundongos , Camundongos SCID , Mutação , Transplante de Neoplasias , Células-Tronco Neoplásicas/patologia , Neurofibromina 1/genética , PTEN Fosfo-Hidrolase/genética , Transplante Heterólogo , Proteína Supressora de Tumor p53/genética
4.
World Neurosurg ; 134: 434-437, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31678437

RESUMO

BACKGROUND: Neurofibromatosis type 1 (NF1), a dysregulated neurocutaneous disorder, is an autosomal dominant genetic disease caused by mutations in the NF1 gene. Anaplastic astrocytoma is rare in NF1 patients, and research has proposed that high-grade astrocytomas could be due to larger germ-line mutations in NF1.We present a clinical and molecular study of a Chinese family with NF1. CASE DESCRIPTION: A 28-year-old male patient with NF1 presents with headache, vertigo, and dizziness. Histopathologic examination and molecular features identified a cerebellar anaplastic astrocytoma, IDH-wildtype. The patient underwent gross total resection of the lesion and received radiotherapy and chemotherapy. A rare splice error mutation (c.4110+945A>G) in intron 23-2 of NF1 was identified by next-generation sequencing in the proband. Sanger sequencing identified and confirmed it in some affected family members. CONCLUSIONS: We present a unique case of NF1 with anaplastic astrocytoma that revealed a rare splice error mutation in the NF1 gene in the family.


Assuntos
Astrocitoma/genética , Neoplasias Cerebelares/genética , Genes da Neurofibromatose 1 , Neurofibromatose 1/genética , Neurofibromatose 1/patologia , Adulto , Grupo com Ancestrais do Continente Asiático , Humanos , Masculino , Mutação , Neurofibromina 1/genética
5.
Genes Chromosomes Cancer ; 59(2): 119-124, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31515834

RESUMO

Neuroblastoma, the most common extracranial solid tumor of childhood, can present in multiple primary sites, but the extent of genetic heterogeneity among tumor foci, as well as the presence or absence of common oncogenic drivers, remains unknown. Although PHOX2B genetic aberrations can cause familial neuroblastoma, they demonstrate incomplete penetrance with respect to neuroblastoma pathogenesis, suggesting that additional undescribed oncogenic drivers are necessary for tumor development. We performed comprehensive molecular characterization of neuroblastoma tumors from two siblings affected by familial multifocal neuroblastoma, including whole exome sequencing and single-nucleotide polymorphism (SNP) arrays of tumor and matched blood samples. Data were processed and analyzed using established bioinformatics algorithms to evaluate for germline and somatic mutations and copy number variations (CNVs). We confirmed the presence of a PHOX2B deletion and NF1 mutation across all tumor samples and the germline genome. Matched tumor-blood whole exome sequencing also identified 365 genes that contained nonsilent coding mutations across all tumor samples, with no recurrent mutations across all tumors. SNP arrays also showed significant heterogeneity with respect to CNVs. The only common CNV across all tumors was 17q gain, with differing chromosomal coordinates across samples but a common region of overlap distal to 17q21.31, suggesting this adverse prognostic biomarker may offer insight about additional drivers for multifocal neuroblastoma in patients with germline PHOX2B or NF1 aberrations. Molecular characterization of all tumors from patients with multifocal primary neuroblastoma has potential to yield novel insights on neuroblastoma pathogenesis.


Assuntos
Proteínas de Homeodomínio/genética , Neuroblastoma/genética , Neurofibromina 1/genética , Fatores de Transcrição/genética , Pré-Escolar , Biologia Computacional/métodos , Variações do Número de Cópias de DNA , Genes da Neurofibromatose 1 , Heterogeneidade Genética , Predisposição Genética para Doença , Proteínas de Homeodomínio/metabolismo , Humanos , Lactente , Perda de Heterozigosidade , Masculino , Mutação , Neurofibromina 1/metabolismo , Polimorfismo de Nucleotídeo Único , Irmãos , Fatores de Transcrição/metabolismo , Sequenciamento Completo do Exoma/métodos
6.
Nat Commun ; 10(1): 5585, 2019 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-31811119

RESUMO

Linked-read sequencing provides long-range information on short-read sequencing data by barcoding reads originating from the same DNA molecule, and can improve detection and breakpoint identification for structural variants (SVs). Here we present LinkedSV for SV detection on linked-read sequencing data. LinkedSV considers barcode overlapping and enriched fragment endpoints as signals to detect large SVs, while it leverages read depth, paired-end signals and local assembly to detect small SVs. Benchmarking studies demonstrate that LinkedSV outperforms existing tools, especially on exome data and on somatic SVs with low variant allele frequencies. We demonstrate clinical cases where LinkedSV identifies disease-causal SVs from linked-read exome sequencing data missed by conventional exome sequencing, and show examples where LinkedSV identifies SVs missed by high-coverage long-read sequencing. In summary, LinkedSV can detect SVs missed by conventional short-read and long-read sequencing approaches, and may resolve negative cases from clinical genome/exome sequencing studies.


Assuntos
Sequência de Bases , Análise Mutacional de DNA/métodos , Exoma , Variação Estrutural do Genoma/genética , Deleção de Sequência , Pontos de Quebra do Cromossomo , Genoma/genética , Genoma Humano , Humanos , Modelos Genéticos , Neurofibromina 1/genética , Análise de Sequência de DNA , Software
7.
BMC Cancer ; 19(1): 1196, 2019 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-31805970

RESUMO

BACKGROUND: NF1(Neurofibromatosis type 1) is an autosomal dominant genetic disorder. Patients with NF1 have an increased risk of developing benign or malignant tumours, such as gastrointestinal stromal tumours (GISTs). However, the coexistence of NF1, GIST and colon cancer is very rare, and few cases have been reported in the literature. CASE PRESENTATION: We admitted a case of a 64-year-old man with type 1 neurofibromatosis, GISTs, and ascending colon cancer. This case was characterized by café-au-lait macules, discrete cutaneous neurofibromas, nodular neurofibromas, multiple jejunal tumours, and ascending colon cancer. Laparoscopic exploration revealed ascending colon cancer and multiple jejunal tumours. Laparoscopic right hemicolectomy and local excision of the jejunal tumours were performed successfully. The pathological results confirmed moderate differentiated adenocarcinoma of the ascending colon with multiple jejunal GISTs (low risk, very low risk). Moreover, the immunohistochemistry results of multiple jejunal GISTs suggest that NF1 is positive. Whole-exome sequencing (WES) of colon cancer revealed mutations in more than 20 genes, including KRAS, PIK3CA, APC, SMAD4, etc. The results of whole-exome sequencing (WES) of jejunal GISTs revealed an NF1 mutation and no KIT or PDGFR gene mutation. CONCLUSION: We report a rare case of simultaneous NF1, GIST and colon adenocarcinoma. For patients with NF1, benign and/or malignant tumours are often combined. Therefore, these patients should undergo regular physical examinations so that early detection and early treatment can be achieved.


Assuntos
Colo Ascendente/cirurgia , Neoplasias do Colo/cirurgia , Tumores do Estroma Gastrointestinal/cirurgia , Neurofibromatose 1/cirurgia , Colectomia , Colo Ascendente/patologia , Neoplasias do Colo/genética , Neoplasias do Colo/patologia , Comorbidade , Tumores do Estroma Gastrointestinal/genética , Tumores do Estroma Gastrointestinal/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Neurofibromatose 1/genética , Neurofibromatose 1/patologia , Neurofibromina 1/genética , Sequenciamento Completo do Exoma
8.
Biomed Res Int ; 2019: 2721357, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31886188

RESUMO

Neurofibromatosis type 1 (NF1) is a progressive neurocutaneous disorder in humans, mainly characterized by café-au-lait macules (CALMs) and neurofibromas. NF1 is caused by variants of the neurofibromin 1 gene (NF1), which encodes a Ras-GTPase-activating protein called neurofibromin. NF1 variants may result in loss of neurofibromin function and elevation of cell proliferation and tumor formation. In this study, a Chinese NF1 family with an autosomal dominant inheritance pattern was recruited. Exome sequencing and Sanger sequencing were performed to discover the causative variant responsible for the family, followed by molecular analysis of effect of the mutated NF1 protein on Ras activity. A novel frameshift variant c.541dupC (p.(Gln181Profs∗20)) in the NF1 gene was identified in all three affected family members. The variant cosegregated with the disease phenotypes in the pedigree and was absent in 100 healthy controls. Bioinformatic analysis showed that the variant c.541dupC (p.(Gln181Profs∗20)) was pathogenic. The further molecular analysis verified the cells expressing NF1 variant p.(Gln181Profs∗20) partially enhanced Ras activity and elevated cell proliferation and tumor formation due to loss of neurofibromin function caused by the variant. Taken together, the data strongly advocate the c.541dupC (p.(Gln181Profs∗20)) variant as the underlying genetic cause of the Chinese family with NF1. Moreover, our findings broaden the spectrum of NF1 variants and provide molecular insights into the pathogenesis of NF1.


Assuntos
Manchas Café com Leite/genética , Predisposição Genética para Doença , Neurofibromatose 1/genética , Neurofibromina 1/genética , Adolescente , Adulto , Manchas Café com Leite/fisiopatologia , Criança , China , Feminino , Mutação da Fase de Leitura/genética , Humanos , Masculino , Pessoa de Meia-Idade , Neurofibromatose 1/fisiopatologia , Linhagem , Fenótipo , Sequenciamento Completo do Exoma , Adulto Jovem
9.
Genes (Basel) ; 10(11)2019 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-31717729

RESUMO

BACKGROUND: Neurofibromatosis 1 (NF1) is one of the most common dominantly inherited genetic disorders worldwide, with an age-dependent phenotypic expression. Exploring the mutational spectrum and clinical presentation of NF1 patients at different ages from a diverse population will aid the understanding of genotype-phenotype correlations. METHODS: In this study, 95 Chinese children with clinical suspicion of NF1 mainly due to the presence of multiple café-au-lait macules (CALMs) were subjected to medical exome-sequencing analysis and Sanger confirmation of pathogenic variants. Clinical presentations were evaluated regarding dermatological, ocular, neurological, and behavioral features. RESULTS: Pathogenic or likely pathogenic NF1 variants were detected in 71.6% (68/95) of patients; 20 pathogenic variants were not previously reported, indicating that Chinese NF1 patients are still understudied. Parental Sanger sequencing confirmation revealed 77.9% of de novo variants, a percentage that was much higher than expected. The presence of a higher number of NF1-related features at young ages was correlated with positive diagnostic findings. In addition to CALMs, neurological and behavioral features had a high expression among Chinese NF1 children. We attempted to correlate short stature with the locations of the pathogenic variants across the NF1 gene. It is interesting to notice that variants detected in the C-terminal region of the NF1 gene were less likely to be associated with short stature among the NF1 patients, whereas variants at the N-terminal were highly penetrant for the short stature phenotype. CONCLUSION: Novel NF1 pathogenic variants are yet to be uncovered in under-studied NF1 patient populations; their identification will help to reveal novel genotype-phenotype correlations.


Assuntos
Taxa de Mutação , Neurofibromatose 1/genética , Fenótipo , Adolescente , Criança , Pré-Escolar , China , Feminino , Humanos , Lactente , Masculino , Neurofibromatose 1/patologia , Neurofibromina 1/genética
10.
Int J Mol Sci ; 20(21)2019 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31683701

RESUMO

Conjunctival melanoma (CjM) is a rare, primary cancer of the ocular region. Genetic and epigenetic characteristics of conjunctival melanoma have not been completely elucidated yet. Conjunctival melanoma presents similarities with cutaneous melanoma, with substantial differences in the biological behavior. We reviewed the genetic and epigenetic insights of CjM involved in invasion and metastatic spread. CjM is commonly characterized by mutations of v-raf murine sarcoma viral oncogene homolog B1 (BRAF), neurofibromin 1 (NF1) and telomerase reverse transcriptase (TERT), high expression of mammalian target of rapamycin (mTOR) and heat shock protein 90 (HSP90), frequent phosphatase and tensin homolog (PTEN) loss and upregulation of specific miRNAs. These features should identify CjM as a distinct subset of melanoma with its own profile, which is more similar to cutaneous melanoma than mucosal melanoma and remarkably different from uveal melanoma.


Assuntos
Neoplasias da Túnica Conjuntiva/genética , Epigênese Genética/genética , Predisposição Genética para Doença/genética , Melanoma/genética , Mutação , Humanos , Neurofibromina 1/genética , PTEN Fosfo-Hidrolase/genética , Proteínas Proto-Oncogênicas B-raf/genética , Telomerase/genética
11.
Exp Suppl ; 111: 129-147, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31588531

RESUMO

Pheochromocytomas (Pheo) and paragangliomas (PGL) are rare tumors originating from catecholamine-producing chromaffin cells. They occur approximately in 0.1% of patients affected with hypertonia. Pheo/PGL may manifest itself at any age; in 10% of the patients, the disease is bilateral, and also in 10% it occurs outside of the adrenal medulla. From a genetic aspect, a considerable proportion of these tumors represents a prototype for an autosomal dominantly inherited syndrome with incomplete penetrance. In addition, to date more than 15 genes have been identified representing genetic susceptibility for Pheo/PGL and accounting for 40% of all cases. In general, in familiar cases, the tumor manifests at younger age, and they are often occurring as multiplex tumors. Permanent recovery can be achieved with an early diagnosis and with a successful surgical removal of the tumor tissue. On the other hand, undiagnosed, hormonally active Pheos may lead to severe, or even lethal, consequences. This chapter will summarize our recent knowledge about the genetics of Pheo/PGL, focusing on tumor syndromes where Pheo/PGLs are among the main manifestations.


Assuntos
Neurofibromina 1/genética , Feocromocitoma/genética , Proteína Supressora de Tumor Von Hippel-Lindau/genética , Neoplasias das Glândulas Suprarrenais/genética , Catecolaminas , Humanos , Paraganglioma/genética
12.
PLoS Biol ; 17(10): e3000477, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31600280

RESUMO

The striatum plays a fundamental role in motor learning and reward-related behaviors that are synergistically shaped by populations of D1 dopamine receptor (D1R)- and D2 dopamine receptor (D2R)-expressing medium spiny neurons (MSNs). How various neurotransmitter inputs converging on common intracellular pathways are parsed out to regulate distinct behavioral outcomes in a neuron-specific manner is poorly understood. Here, we reveal that distinct contributions of D1R-MSNs and D2R-MSNs towards reward and motor behaviors are delineated by the multifaceted signaling protein neurofibromin 1 (NF1). Using genetic mouse models, we show that NF1 in D1R-MSN modulates opioid reward, whereas loss of NF1 in D2R-MSNs delays motor learning by impeding the formation and consolidation of repetitive motor sequences. We found that motor learning deficits upon NF1 loss were associated with the disruption in dopamine signaling to cAMP in D2R-MSN. Restoration of cAMP levels pharmacologically or chemogenetically rescued the motor learning deficits seen upon NF1 loss in D2R-MSN. Our findings illustrate that multiplex signaling capabilities of MSNs are deployed at the level of intracellular pathways to achieve cell-specific control over behavioral outcomes.


Assuntos
Corpo Estriado/fisiologia , Neurofibromina 1/metabolismo , Neurônios/fisiologia , Animais , AMP Cíclico/metabolismo , Dopamina/metabolismo , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Modelos Animais , Atividade Motora/fisiologia , Neurônios/metabolismo , Receptores de Dopamina D1/metabolismo , Receptores de Dopamina D2/metabolismo , Recompensa , Transdução de Sinais
13.
Genes (Basel) ; 10(11)2019 10 24.
Artigo em Inglês | MEDLINE | ID: mdl-31652930

RESUMO

Neurofibromatosis type 1 (NF1) is a cancer predisposition syndrome that results from dominant loss-of-function mutations mainly in the NF1 gene. Large rearrangements are present in 5-10% of affected patients, generally encompass NF1 neighboring genes, and are correlated with a more severe NF1 phenotype. Evident genotype-phenotype correlations and the importance of the co-deleted genes are difficult to establish. In our study we employed an evolutionary approach to provide further insights into the understanding of the fundamental function of genes that are co-deleted in subjects with NF1 microdeletions. Our goal was to access the ortholog and paralog relationship of these genes in primates and verify if purifying or positive selection are acting on these genes. Fourteen genes were analyzed in twelve mammalian species. Of these, four and ten genes showed positive selection and purifying selection, respectively. The protein, RNF135, showed three sites under positive selection at the RING finger domain, which may have been selected to increase efficiency in ubiquitination routes in primates. The phylogenetic analysis suggests distinct evolutionary constraint between the analyzed genes. With these analyses, we hope to help clarify the correlation of the co-deletion of these genes and the more severe phenotype of NF1.


Assuntos
Evolução Molecular , Deleção de Genes , Neurofibromatose 1/genética , Animais , Bovinos , Cães , Humanos , Camundongos , Neurofibromina 1/genética , Primatas , Ratos , Seleção Genética , Ubiquitina-Proteína Ligases/genética
14.
Proc Natl Acad Sci U S A ; 116(44): 22122-22131, 2019 10 29.
Artigo em Inglês | MEDLINE | ID: mdl-31611389

RESUMO

KRAS mutations occur in ∼35% of colorectal cancers and promote tumor growth by constitutively activating the mitogen-activated protein kinase (MAPK) pathway. KRAS mutations at codons 12, 13, or 61 are thought to prevent GAP protein-stimulated GTP hydrolysis and render KRAS-mutated colorectal cancers unresponsive to epidermal growth factor receptor (EGFR) inhibitors. We report here that KRAS G13-mutated cancer cells are frequently comutated with NF1 GAP but NF1 is rarely mutated in cancers with KRAS codon 12 or 61 mutations. Neurofibromin protein (encoded by the NF1 gene) hydrolyzes GTP directly in complex with KRAS G13D, and KRAS G13D-mutated cells can respond to EGFR inhibitors in a neurofibromin-dependent manner. Structures of the wild type and G13D mutant of KRAS in complex with neurofibromin (RasGAP domain) provide the structural basis for neurofibromin-mediated GTP hydrolysis. These results reveal that KRAS G13D is responsive to neurofibromin-stimulated hydrolysis and suggest that a subset of KRAS G13-mutated colorectal cancers that are neurofibromin-competent may respond to EGFR therapies.


Assuntos
Neoplasias Colorretais/genética , Receptores ErbB/antagonistas & inibidores , Guanosina Trifosfato/metabolismo , Neurofibromina 1/química , Proteínas Proto-Oncogênicas p21(ras)/química , Substituição de Aminoácidos , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Domínio Catalítico , Linhagem Celular , Neoplasias Colorretais/tratamento farmacológico , Proteínas Ativadoras de GTPase/metabolismo , Guanosina Trifosfato/química , Humanos , Hidrólise , Modelos Moleculares , Neurofibromina 1/metabolismo , Neurofibromina 1/fisiologia , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Proto-Oncogênicas p21(ras)/genética
15.
Genes (Basel) ; 10(9)2019 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-31487937

RESUMO

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.


Assuntos
Cardiopatias Congênitas/genética , Mutação , Neurofibromatose 1/genética , Neurofibromina 1/genética , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Cardiopatias Congênitas/epidemiologia , Humanos , Lactente , Itália , Masculino , Pessoa de Meia-Idade , Neurofibromatose 1/epidemiologia , Fenótipo , Prevalência
16.
Curr Opin Oncol ; 31(6): 554-561, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31436563

RESUMO

PURPOSE OF REVIEW: The current review summarizes recent advances on three important issues in neurofibromatosis type 1 (NF1) management: the identification of specific NF1 gene mutations predicting the risk for developing neurological malignancies; the molecular features of NF1-associated tumors and their differences from sporadic neoplasms; genetic, epigenetic, or microenviromental factors leading benign tumors to a malignant transformation in NF1. RECENT FINDINGS: The association between the risk of developing optic pathway glioma and specific germiline NF1 mutations is still debated and further studies are needed with large, new cohorts of patients. The available evidences suggest that gliomas and malignant peripheral nerve sheath tumors (MPNSTs) in NF1 have a distinct genetic signatures, different from those observed in sporadic neoplasms. Some neoplasms, very rare in general population, such as subependymal giant cell astrocytoma, can be observed in NF1. A subgroup of low-grade NF1-gliomas, some MPNSTs and plexiform neurofibromas contain abundant T lymphocyte infiltrates suggesting that immunotherapy could be a potential therapeutic approach. SUMMARY: These data support the notion that next-generation sequencing efforts are helpful in the genetic characterization of NF1-associated malignancies A better knowledge of those tumors at the genomic level, is essential for addressing new treatments and may contribute to a deeper comprehension of NF1/RAS signaling also in sporadic cancers.


Assuntos
Neurofibromatose 1/patologia , Glioma do Nervo Óptico/patologia , Animais , Transformação Celular Neoplásica , Mutação em Linhagem Germinativa , Humanos , Neurofibromatose 1/genética , Neurofibromina 1/genética , Glioma do Nervo Óptico/genética
17.
Genes (Basel) ; 10(8)2019 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-31370276

RESUMO

Pigmentary manifestations can represent an early clinical sign in children affected by Neurofibromatosis type 1 (NF1), Legius syndrome, and other neurocutaneous disorders. The differential molecular diagnosis of these pathologies is a challenge that can now be met by combining next generation sequencing of target genes with concurrent second-level tests, such as multiplex ligation-dependent probe amplification and RNA analysis. We clinically and genetically investigated 281 patients, almost all pediatric cases, presenting with either NF1 (n = 150), only pigmentary features (café au lait macules with or without freckling; (n = 95), or clinical suspicion of other RASopathies or neurocutaneous disorders (n = 36). The causative variant was identified in 239 out of the 281 patients analyzed (85.1%), while 42 patients remained undiagnosed (14.9%). The NF1 and SPRED1 genes were mutated in 73.3% and 2.8% of cases, respectively. The remaining 8.9% carried mutations in different genes associated with other disorders. We achieved a molecular diagnosis in 69.5% of cases with only pigmentary manifestations, allowing a more appropriate clinical management of these patients. Our findings, together with the increasing availability and sharing of clinical and genetic data, will help to identify further novel genotype-phenotype associations that may have a positive impact on patient follow-up.


Assuntos
Manchas Café com Leite/genética , Mutação , Neurofibromatose 1/genética , Proteínas Adaptadoras de Transdução de Sinal/genética , Adolescente , Adulto , Manchas Café com Leite/patologia , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Neurofibromatose 1/patologia , Neurofibromina 1/genética , Fenótipo
18.
Genes (Basel) ; 10(9)2019 08 22.
Artigo em Inglês | MEDLINE | ID: mdl-31443423

RESUMO

Neurofibromatosis type 1 (NF1) is an autosomal dominant disease with complete penetrance but high variable expressivity. NF1 is caused by loss-of-function mutations in the NF1 gene, a negative regulator of the RAS-MAPK pathway. The NF1 gene has one of the highest mutation rates in human disorders, which may explain the outbreak of independent de novo variants in the same family. Here, we report the co-occurrence of pathogenic variants in the NF1 and SPRED1 genes in six families with NF1 and Legius syndrome, using next-generation sequencing. In five of these families, we observed the co-occurrence of two independent NF1 variants. All NF1 variants were classified as pathogenic, according to the American College of Medical Genetics and Genomics and the Association for Molecular Pathology (ACMG-AMP) guidelines. In the sixth family, one sibling inherited a complete deletion of the NF1 gene from her mother and carried a variant of unknown significance in the SPRED1 gene. This variant was also present in her brother, who was diagnosed with Legius syndrome, a differential diagnosis of NF1. This work illustrates the complexity of molecular diagnosis in a not-so-rare genetic disease.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Manchas Café com Leite/genética , Neurofibromatose 1/genética , Neurofibromina 1/genética , Fenótipo , Adolescente , Adulto , Manchas Café com Leite/complicações , Manchas Café com Leite/patologia , Criança , Feminino , Humanos , Masculino , Mutação , Neurofibromatose 1/complicações , Neurofibromatose 1/patologia , Linhagem
19.
Genes (Basel) ; 10(9)2019 08 28.
Artigo em Inglês | MEDLINE | ID: mdl-31466283

RESUMO

Neurofibromatosis Type 1 (NF1) is caused by pathogenic variants in the NF1 gene encoding neurofibromin. Definition of NF1 protein-protein interactions (PPIs) has been difficult and lacks replication, making it challenging to define binding partners that modulate its function. We created a novel tandem affinity purification (TAP) tag cloned in frame to the 3' end of the full-length murine Nf1 cDNA (mNf1). We show that this cDNA is functional and expresses neurofibromin, His-Tag, and can correct p-ERK/ERK ratios in NF1 null HEK293 cells. We used this affinity tag to purify binding partners with Strep-Tactin®XT beads and subsequently, identified them via mass spectrometry (MS). We found the tagged mNf1 can affinity purify human neurofibromin and vice versa, indicating that neurofibromin oligomerizes. We identify 21 additional proteins with high confidence of interaction with neurofibromin. After Metacore network analysis of these 21 proteins, eight appear within the same network, primarily keratins regulated by estrogen receptors. Previously, we have shown that neurofibromin levels negatively regulate keratin expression. Here, we show through pharmacological inhibition that this is independent of Ras signaling, as the inhibitors, selumetinib and rapamycin, do not alter keratin expression. Further characterization of neurofibromin oligomerization and binding partners could aid in discovering new neurofibromin functions outside of Ras regulation, leading to novel drug targets.


Assuntos
Queratinas/metabolismo , Neurofibromina 1/metabolismo , Células HEK293 , Humanos , Ligação Proteica , Multimerização Proteica
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