RESUMEN
Neurofibromatosis type 1 (NF1), an autosomal dominant genetic disorder, is caused by mutations in the NF1 gene, which encodes the GTPase-activating protein neurofibromin. The pathogenesis of the tumor progression of benign plexiform neurofibromas (PNs) and malignant peripheral nerve sheath tumors (MPNSTs) remain unclear. Here, we found that interferon-induced transmembrane protein 1 (IFITM1) was downregulated in MPNST tissues compared to those in PN tissues from patients with NF1. Overexpression of IFITM1 in NF1-associated MPNST cells resulted in a significant decrease in Ras activation (GTP-Ras) and downstream extracellular regulatory kinase 1/2 (ERK1/2) phosphorylation, whereas downregulation of IFITM1 via treatment with small interfering RNA in normal Schwann cells had the opposite result, indicating that expression levels of IFITM1 are closely associated with tumor progression in NF1. Treatment of MPNST cells with interferon-gamma (IFN-γ) significantly augmented the expression of IFITM1, thereby leading to a decrease in Ras and ERK1/2 activation. Despite the small number of patient samples, these findings may potentially provide a new target for chemotherapy in patients with NF1-associated MPNSTs. In xenograft mice injected with MPNST cells, IFN-γ treatment successfully suppressed tumor progression with increased IFITM1 expression and decreased Ras and ERK1/2 activation in tumor tissues. Collectively, these results suggest that IFITM1 is closely involved in MPNST pathogenesis and that IFN-γ is a good candidate for the therapeutic treatment of MPNSTs in NF1.
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Antígenos de Diferenciación , Neoplasias de la Vaina del Nervio , Neurofibromatosis 1 , Humanos , Animales , Neurofibromatosis 1/metabolismo , Neurofibromatosis 1/genética , Neurofibromatosis 1/patología , Neurofibromatosis 1/complicaciones , Ratones , Neoplasias de la Vaina del Nervio/metabolismo , Neoplasias de la Vaina del Nervio/genética , Neoplasias de la Vaina del Nervio/patología , Línea Celular Tumoral , Antígenos de Diferenciación/metabolismo , Antígenos de Diferenciación/genética , Regulación hacia Abajo , Femenino , Regulación Neoplásica de la Expresión Génica , Masculino , Interferón gamma/metabolismo , Sistema de Señalización de MAP Quinasas , Proteínas ras/metabolismo , Proteínas ras/genética , Neurofibromina 1/genética , Neurofibromina 1/metabolismo , AdultoRESUMEN
In this issue of Developmental Cell, Shiraishi et al. investigate the epigenetic changes occurring during the formation of SHH medulloblastoma and show that an epigenomic shift renders Nuclear Factor I family of transcription factors oncogenic.
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Epigénesis Genética , Proteínas Hedgehog , Meduloblastoma , Factores de Transcripción NFI , Meduloblastoma/genética , Meduloblastoma/patología , Meduloblastoma/metabolismo , Humanos , Proteínas Hedgehog/metabolismo , Proteínas Hedgehog/genética , Factores de Transcripción NFI/metabolismo , Factores de Transcripción NFI/genética , Animales , Neoplasias Cerebelosas/genética , Neoplasias Cerebelosas/patología , Neoplasias Cerebelosas/metabolismo , Neurofibromina 1/genética , Neurofibromina 1/metabolismo , RatonesRESUMEN
BACKGROUND: Increased case reports have shown that patients with NF1 have an increased risk of extensive vascular vasculopathy. Previous studies demonstrated the presence of macrophages and smooth muscle cells in the neoplastic intima of carotid arteries after injury in Nf1+/- mice. However, whether NF1 gene mutations affect macrophage polarization and macrophage-smooth muscle cell interactions remains to be elucidated. METHODS: Scratch assay and transwell assay were utilized to detect cell migration ability. The dye 2',7'dichlorofluorescin diacetate and neutral red stain were used to assess intracellular ROS production and cell phagocytosis function, respectively. Proteins and mRNA expression were determined by western blot, RT-qPCR, and immunofluorescence. Finally, the macrophage (MAC) and vascular smooth muscle cell (VSMC) co-culture system was used to detect cellular crosstalk. RESULTS: Cell function assays confirmed that the Nf1-Q181X point mutation attenuated the phagocytosis of bone marrow-derived macrophages (BMDMs) and promoted the migration and ROS production of BMDMs. Moreover, we found that the Nf1-Q181X point mutation inhibited M1 but promoted M2 macrophage polarization by down-regulating p38, ERK, and JNK and up-regulating the Akt/STAT3 signaling pathway, respectively. Furthermore, in the MAC-VSMC co-culture system, we demonstrated that Nf1-Q181X point mutation-activated M2 BMDMs promoted proliferation and migration of VSMCs and induced the transformation of VSMCs from contractile phenotype to synthetic phenotype. CONCLUSION: The findings suggest that the Nf1-Q181X point mutation can mediate macrophage polarization and promote smooth muscle cell proliferation and migration, providing clinical clues for the treatment of NF1-complicated vasculopathy.
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Movimiento Celular , Proliferación Celular , Macrófagos , Miocitos del Músculo Liso , Neurofibromina 1 , Mutación Puntual , Proteínas Proto-Oncogénicas c-akt , Transducción de Señal , Movimiento Celular/genética , Animales , Proliferación Celular/genética , Macrófagos/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Miocitos del Músculo Liso/metabolismo , Ratones , Neurofibromina 1/genética , Neurofibromina 1/metabolismo , Factor de Transcripción STAT3/metabolismo , Factor de Transcripción STAT3/genética , Músculo Liso Vascular/metabolismo , Músculo Liso Vascular/citología , Fagocitosis/genética , Especies Reactivas de Oxígeno/metabolismo , Ratones Endogámicos C57BL , Técnicas de CocultivoRESUMEN
Plexiform neurofibromas (PNFs) are a prevalent and severe phenotype associated with NF1, characterized by a high teratogenic rate and potential for malignant transformation. The growth and recurrence of PNFs are attributed to aberrant proliferation and migration of Nf1-deficient Schwann cells. Protein tyrosine phosphatase receptor S (PTPRS) is believed to modulate cell migration and invasion by inhibiting the EMT process in NF1-derived malignant peripheral nerve sheath tumors. Nevertheless, the specific role of PTPRS in NF1-derived PNFs remains to be elucidated. The study utilized the GEO database and tissue microarray to illustrate a decrease in PTPRS expression in PNF tissues, linked to tumor recurrence. Furthermore, the down- and over-expression of PTPRS in Nf1-deficient Schwann cell lines resulted in the changes of cell migration and EMT processes. Additionally, RTK assay and WB showed that PTPRS knockdown can promote EGFR expression and phosphorylation. The restoration of EMT processes disrupted by alterations in PTPRS levels in Schwann cells can be achieved through EGFR knockdown and EGFR inhibitor. Moreover, high EGFR expression has been significantly correlated with poor prognosis. These findings underscore the potential role of PTPRS as a tumor suppressor in the recurrence of PNF via the regulation of EGFR-mediated EMT processes, suggesting potential targets for future clinical interventions.
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Movimiento Celular , Transición Epitelial-Mesenquimal , Receptores ErbB , Neurofibroma Plexiforme , Células de Schwann , Humanos , Línea Celular Tumoral , Receptores ErbB/metabolismo , Receptores ErbB/genética , Regulación Neoplásica de la Expresión Génica , Recurrencia Local de Neoplasia/patología , Recurrencia Local de Neoplasia/genética , Neurofibroma Plexiforme/patología , Neurofibroma Plexiforme/genética , Neurofibroma Plexiforme/metabolismo , Neurofibromatosis 1/genética , Neurofibromatosis 1/metabolismo , Neurofibromatosis 1/patología , Neurofibromina 1/genética , Neurofibromina 1/metabolismo , Fosforilación , Proteínas Tirosina Fosfatasas Clase 2 Similares a Receptores/genética , Proteínas Tirosina Fosfatasas Clase 2 Similares a Receptores/metabolismo , Células de Schwann/metabolismo , Células de Schwann/patología , Transducción de SeñalRESUMEN
Neurofibromatosis type 1 (NF1) is a human genetic disorder caused by variants in the NF1 gene. Plexiform neurofibromas, one of many NF1 manifestations, are benign peripheral nerve sheath tumors occurring in up to 50% of NF1 patients. A substantial fraction of NF1 pathogenetic variants are nonsense mutations, which result in the synthesis of truncated non-functional NF1 protein (neurofibromin). To date, no therapeutics have restored neurofibromin expression or addressed the consequences of this protein's absence in NF1 nonsense mutation patients, but nonsense suppression is a potential approach to the problem. Ataluren is a small molecule drug that has been shown to stimulate functional nonsense codon readthrough in several models of nonsense mutation diseases, as well as in Duchenne muscular dystrophy patients. To test ataluren's potential applicability in nonsense mutation NF1 patients, we evaluated its therapeutic effects using three treatment regimens in a previously established NF1 patient-derived (c.2041C > T; p.Arg681X) nonsense mutation mouse model. Collectively, our experiments indicate that: i) ataluren appeared to slow the growth of neurofibromas and alleviate some paralysis phenotypes, ii) female Nf1-nonsense mutation mice manifested more severe paralysis and neurofibroma phenotypes than male mice, iii) ataluren doses with apparent effectiveness were lower in female mice than in male mice, and iv) age factors also influenced ataluren's effectiveness.
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Codón sin Sentido , Modelos Animales de Enfermedad , Neurofibromatosis 1 , Neurofibromina 1 , Animales , Codón sin Sentido/efectos de los fármacos , Ratones , Masculino , Femenino , Neurofibromatosis 1/genética , Neurofibromatosis 1/tratamiento farmacológico , Neurofibromina 1/genética , Oxadiazoles/farmacología , Oxadiazoles/uso terapéutico , Humanos , Ratones Endogámicos C57BL , Ratones TransgénicosRESUMEN
Neurofibromatosis type 1, a genetic disorder caused by pathogenic germline variations in NF1, predisposes individuals to the development of tumors, including cutaneous and plexiform neurofibromas (CNs and PNs), optic gliomas, astrocytomas, juvenile myelomonocytic leukemia, high-grade gliomas and malignant peripheral nerve sheath tumors (MPNSTs), which are chemotherapy- and radiation-resistant sarcomas with poor survival. Loss of NF1 also occurs in sporadic tumors, such as glioblastoma (GBM), melanoma, breast, ovarian and lung cancers. We performed a high-throughput screen for compounds that were synthetic lethal with NF1 loss, which identified several leads, including the small molecule Y102. Treatment of cells with Y102 perturbed autophagy, mitophagy and lysosome positioning in NF1-deficient cells. A dual proteomics approach identified BLOC-one-related complex (BORC), which is required for lysosome positioning and trafficking, as a potential target of Y102. Knockdown of a BORC subunit using siRNA recapitulated the phenotypes observed with Y102 treatment. Our findings demonstrate that BORC might be a promising therapeutic target for NF1-deficient tumors.
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Lisosomas , Neurofibromina 1 , Humanos , Lisosomas/metabolismo , Neurofibromina 1/genética , Neurofibromina 1/metabolismo , Neurofibromatosis 1/metabolismo , Neurofibromatosis 1/genética , Neurofibromatosis 1/patología , Autofagia/efectos de los fármacos , Mutaciones Letales Sintéticas , Transporte de Proteínas/efectos de los fármacosRESUMEN
Genetic testing is recommended for all patients with pheochromocytomas and paragangliomas (PPGL) to establish genotype-phenotype associations. We investigated germline mutations in 59 patients with PPGL at six Korean university hospitals using next-generation sequencing (NGS) targeting 38 PPGL-associated genes, including those recommended by the Korean PPGL Task Force. Germline mutations were identified in 13 patients (22%), and affected four genes: RET, NF1, VHL, and SDHD. Germline mutations were significantly associated with a family history of PPGL, smaller tumor size, and the presence of other types of tumors. Using 95 Korean PPGL cases with germline mutations identified through a literature review and 13 cases from our cohort, we characterized genotype-phenotype correlations. Mutation hotspots were identified in specific codons of RET (codons 631 and 634), VHL (157 and 167), and SDHB (131 and 253). NF1 mutations varied, indicating the absence of common hotspots. These findings highlight the efficacy of the recommended NGS panel for Korean patients with PPGL and the importance of genetic testing in establishing clinical management and personalized therapeutic strategies.
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Neoplasias de las Glándulas Suprarrenales , Mutación de Línea Germinal , Secuenciación de Nucleótidos de Alto Rendimiento , Paraganglioma , Feocromocitoma , Proteínas Proto-Oncogénicas c-ret , Proteína Supresora de Tumores del Síndrome de Von Hippel-Lindau , Humanos , Feocromocitoma/genética , Feocromocitoma/patología , Paraganglioma/genética , Paraganglioma/patología , República de Corea , Adulto , Femenino , Masculino , Persona de Mediana Edad , Neoplasias de las Glándulas Suprarrenales/genética , Neoplasias de las Glándulas Suprarrenales/patología , Neoplasias de las Glándulas Suprarrenales/diagnóstico , Proteínas Proto-Oncogénicas c-ret/genética , Proteína Supresora de Tumores del Síndrome de Von Hippel-Lindau/genética , Pueblo Asiatico/genética , Succinato Deshidrogenasa/genética , Fenotipo , Estudios de Asociación Genética , Neurofibromina 1/genética , Adolescente , Adulto Joven , Pruebas Genéticas , AncianoRESUMEN
BACKGROUND: Melanomas lacking mutations in BRAF, NRAS and NF1 are frequently referred to as "triple wild-type" (tWT) melanomas. They constitute 5-10 % of all melanomas and remain poorly characterized regarding clinical characteristics and response to therapy. This study investigates the largest multicenter collection of tWT-melanomas to date. METHODS: Targeted next-generation sequencing of the TERT promoter and 29 melanoma-associated genes were performed on 3109 melanoma tissue samples of the prospective multicenter study ADOREG/TRIM of the DeCOG revealing 292 patients suffering from tWT-melanomas. Clinical characteristics and mutational patterns were analyzed. As subgroup analysis, we analyzed 141 tWT-melanoma patients receiving either anti-CTLA4 plus anti-PD1 or anti PD1 monotherapy as first line therapy in AJCC stage IV. RESULTS: 184 patients with cutaneous melanomas, 56 patients with mucosal melanomas, 34 patients with acral melanomas and 18 patients with melanomas of unknown origin (MUP) were included. A TERT promoter mutation could be identified in 33.2 % of all melanomas and 70.5 % of all tWT-melanomas harbored less than three mutations per sample. For the 141 patients with stage IV disease, mPFS independent of melanoma type was 6.2 months (95 % CI: 4-9) and mOS was 24.8 months (95 % CI: 14.2-53.4) after first line anti-CTLA4 plus anti-PD1 therapy. After first-line anti-PD1 monotherapy, mPFS was 4 months (95 %CI: 2.9-8.5) and mOS was 29.18 months (95 % CI: 17.5-46.2). CONCLUSIONS: While known prognostic factors such as TERT promoter mutations and TMB were equally distributed among patients who received either anti-CTLA4 plus anti-PD1 combination therapy or anti-PD1 monotherapy as first line therapy, we did not find a prolonged mPFS or mOS in either of those. For both therapy concepts, mPFS and mOS were considerably shorter than reported for melanomas with known oncogene mutations.
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Inhibidores de Puntos de Control Inmunológico , Melanoma , Mutación , Proteínas Proto-Oncogénicas B-raf , Humanos , Melanoma/tratamiento farmacológico , Melanoma/genética , Melanoma/mortalidad , Melanoma/patología , Melanoma/inmunología , Masculino , Inhibidores de Puntos de Control Inmunológico/uso terapéutico , Femenino , Persona de Mediana Edad , Proteínas Proto-Oncogénicas B-raf/genética , Anciano , Adulto , Neoplasias Cutáneas/genética , Neoplasias Cutáneas/tratamiento farmacológico , Neoplasias Cutáneas/mortalidad , Neoplasias Cutáneas/patología , Neoplasias Cutáneas/inmunología , Neurofibromina 1/genética , Estudios Prospectivos , Supervivencia sin Progresión , Anciano de 80 o más Años , Receptor de Muerte Celular Programada 1/antagonistas & inhibidores , Telomerasa/genética , GTP Fosfohidrolasas/genética , Regiones Promotoras Genéticas , Proteínas de la MembranaRESUMEN
OBJECTIVES: To investigate the clinical and genetic features in a cohort of Chinese families with neurofibromatosis type 1 (NF1). METHODS: The clinical information of 21 patients with NF1 in 10 families was retrospectively analyzed. To broaden the genetic spectrum of NF1, multiplex ligation-dependent probe amplification analysis was performed first, followed by the whole-exome sequencing, in order to identify pathogenic or potentially pathogenic variants of NF1 gene in 10 unrelated Chinese families. RESULTS: Nine different NF1 variants were identified in all 10 families. Of these, 7 were known pathogenic variants and included the exon 1 deletion, exons 1-58 deletion, c.5401C>T (p.Q1801*), c.2291-2A>C, c.484C>T (p.Q162*), c.4922G>A (p.W1641*) and c.1019_1020del (p.S340Cfs*25). The 2 novel variants were c.5197T>C (p.S1733P) and c.783_797delinsC (p.K261Nfs*25). The p.S1733P variant was classified as a variant of uncertain significance, while p.K261Nfs*25 was classified as pathogenic. Hence, the positive detection rate of NF1 variants was 100% (10/10). While the truncating variants were responsible for 60.0% (6/10) of the cases, the splicing variant was responsible for 10% (1/10) of the cases. CONCLUSION: We identified 2 novel heterozygous variants (c.5197T>C and c.783_797delinsC) in the NF1 gene, which broadens the genetic spectrum of the NF1 gene.
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Pueblo Asiatico , Neurofibromatosis 1 , Adolescente , Adulto , Niño , Preescolar , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven , Pueblo Asiatico/genética , China , Pueblos del Este de Asia , Familia , Mutación , Neurofibromatosis 1/genética , Neurofibromina 1/genética , Linaje , Estudios RetrospectivosRESUMEN
The neurofibromatosis type 1 (NF1) RASopathy is associated with persistent fibrotic nonunions (pseudarthrosis) in human and mouse skeletal tissue. Here, we performed spatial transcriptomics to define the molecular signatures occurring during normal endochondral healing following fracture in mice. Within the control fracture callus, we observed spatially restricted activation of morphogenetic pathways, such as TGF-ß, WNT, and BMP. To investigate the molecular mechanisms contributing to Nf1-deficient delayed fracture healing, we performed spatial transcriptomic analysis on a Postn-cre;Nf1fl/- (Nf1Postn) fracture callus. Transcriptional analyses, subsequently confirmed through phospho-SMAD1/5/8 immunohistochemistry, demonstrated a lack of BMP pathway induction in Nf1Postn mice. To gain further insight into the human condition, we performed spatial transcriptomic analysis of fracture pseudarthrosis tissue from a patient with NF1. Analyses detected increased MAPK signaling at the fibrocartilaginous-osseus junction. Similar to that in the Nf1Postn fracture, BMP pathway activation was absent within the pseudarthrosis tissue. Our results demonstrate the feasibility of delineating the molecular and tissue-specific heterogeneity inherent in complex regenerative processes, such as fracture healing, and reconstructing phase transitions representing endochondral bone formation in vivo. Furthermore, our results provide in situ molecular evidence of impaired BMP signaling underlying NF1 pseudarthrosis, potentially informing the clinical relevance of off-label BMP2 as a therapeutic intervention.
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Proteínas Morfogenéticas Óseas , Curación de Fractura , Neurofibromatosis 1 , Seudoartrosis , Transducción de Señal , Transcriptoma , Animales , Seudoartrosis/metabolismo , Seudoartrosis/genética , Ratones , Humanos , Proteínas Morfogenéticas Óseas/metabolismo , Proteínas Morfogenéticas Óseas/genética , Neurofibromatosis 1/genética , Neurofibromatosis 1/metabolismo , Neurofibromatosis 1/complicaciones , Neurofibromatosis 1/patología , Curación de Fractura/genética , Fracturas Óseas/metabolismo , Fracturas Óseas/genética , Modelos Animales de Enfermedad , Neurofibromina 1/genética , Neurofibromina 1/metabolismo , Perfilación de la Expresión GénicaRESUMEN
Low response rate, treatment relapse, and resistance remain key challenges for cancer treatment with immune checkpoint blockade (ICB). Here we report that loss of specific tumor suppressors (TS) induces an inflammatory response and promotes an immune suppressive tumor microenvironment. Importantly, low expression of these TSs is associated with a higher expression of immune checkpoint inhibitory mediators. Here we identify, by using in vivo CRISPR/Cas9 based loss-of-function screening, that NF1, TSC1, and TGF-ß RII as TSs regulating immune composition. Loss of each of these three TSs leads to alterations in chromatin accessibility and enhances IL6-JAK3-STAT3/6 inflammatory pathways. This results in an immune suppressive landscape, characterized by increased numbers of LAG3+ CD8 and CD4 T cells. ICB targeting LAG3 and PD-L1 simultaneously inhibits metastatic progression in preclinical triple negative breast cancer (TNBC) mouse models of NF1-, TSC1- or TGF-ß RII- deficient tumors. Our study thus reveals a role of TSs in regulating metastasis via non-cell-autonomous modulation of the immune compartment and provides proof-of-principle for ICB targeting LAG3 for patients with NF1-, TSC1- or TGF-ß RII-inactivated cancers.
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Antígeno B7-H1 , Inhibidores de Puntos de Control Inmunológico , Proteína del Gen 3 de Activación de Linfocitos , Neoplasias de la Mama Triple Negativas , Proteína 1 del Complejo de la Esclerosis Tuberosa , Microambiente Tumoral , Microambiente Tumoral/inmunología , Animales , Ratones , Femenino , Humanos , Neoplasias de la Mama Triple Negativas/inmunología , Neoplasias de la Mama Triple Negativas/patología , Neoplasias de la Mama Triple Negativas/genética , Inhibidores de Puntos de Control Inmunológico/farmacología , Inhibidores de Puntos de Control Inmunológico/uso terapéutico , Proteína 1 del Complejo de la Esclerosis Tuberosa/genética , Proteína 1 del Complejo de la Esclerosis Tuberosa/metabolismo , Antígeno B7-H1/metabolismo , Antígeno B7-H1/genética , Neurofibromina 1/genética , Neurofibromina 1/metabolismo , Línea Celular Tumoral , Linfocitos T CD8-positivos/inmunología , Inflamación/inmunología , Linfocitos T CD4-Positivos/inmunología , Regulación Neoplásica de la Expresión Génica , Sistemas CRISPR-CasRESUMEN
Neurofibromatosis type 1 (NF1) is a genetic disorder caused by mutations in the NF1 gene. This disorder shows nearly complete penetrance and high phenotypic variability. We used the whole-exome sequencing technique to identify mutations in 32 NF1 cases from 22 Iranian families. A total of 31 variants, including 30 point mutations and one large deletion, were detected. In eight cases, variants were inherited, while they were sporadic in the remaining. Seven novel variants, including c.5576 T > G, c.6658_6659insC, c.2322dupT, c.92_93insAA, c.4360C > T, c.3814C > T, and c.4565_4566delinsC, were identified. The current study is the largest in terms of the sample size of Iranian NF1 cases with identified mutations. The results can broaden the spectrum of NF1 mutations and facilitate the process of genetic counseling in the affected families.
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Secuenciación del Exoma , Genes de Neurofibromatosis 1 , Neurofibromatosis 1 , Neurofibromina 1 , Humanos , Irán , Neurofibromatosis 1/genética , Neurofibromina 1/genética , Femenino , Masculino , Niño , Linaje , Adulto , Mutación Puntual , Mutación , Adolescente , Preescolar , Adulto Joven , Análisis Mutacional de ADN , Eliminación de SecuenciaRESUMEN
Encephalocraniocutaneous lipomatosis (ECCL) is a sporadic congenital condition characterised by ocular, cutaneous and central nervous system involvement. Mosaic activating variants in FGFR1 and KRAS have been reported in several individuals with this syndrome. We report on a patient with neurofibromatosis type 1 (NF1) with a germline pathogenic variant in the NF1 gene and an ECCL phenotype, suggesting ECCL to be part of a spectrum of malformations associated with NF1 pathogenic variants. An anatomical hemispherectomy was performed for intractable epilepsy. Through genetic analysis of blood, cerebral tissue and giant cell lesions in both jaws, we identified the germline NF1 pathogenic variant in all samples and a second-hit pathogenic NF1 variant in cerebral tissue and both giant cell lesions. Both NF1 variants were located on different alleles resulting in somatic mosaicism for a biallelic NF1 inactivation originating in early embryogenesis (second-hit mosaicism or Happle type 2 mosaicism). The biallelic deficit in NF1 in the left hemicranium explains the severe localised, congenital abnormality in this patient. Identical first and second-hit variants in a giant cell lesion of both upper and lower jaws provide confirmatory evidence for an early embryonic second hit involving at least the neural crest. We suggest that the ECCL phenotype may be part of a spectrum of congenital problems associated with mosaic NF1 nullisomy originating during early embryogenesis. The biallelic NF1 inactivation during early embryogenesis mimics the severe activation of the RAS-MAPK pathway seen in ECCL caused by embryonic mosaic activating FGFR1 and KRAS variants in the cranial region. We propose that distinct mechanisms of mosaicism can cause the ECCL phenotype through convergence on the RAS-MAPK pathway.
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Lipomatosis , Mosaicismo , Síndromes Neurocutáneos , Neurofibromina 1 , Fenotipo , Humanos , Lipomatosis/genética , Lipomatosis/patología , Síndromes Neurocutáneos/genética , Síndromes Neurocutáneos/patología , Neurofibromina 1/genética , Alelos , Neurofibromatosis 1/genética , Neurofibromatosis 1/patología , Femenino , Masculino , Mutación de Línea Germinal/genética , Receptor Tipo 1 de Factor de Crecimiento de Fibroblastos/genética , OftalmopatíasRESUMEN
Congenital pseudarthrosis of the tibia (CPT) is a severe pathology marked by spontaneous bone fractures that fail to heal, leading to fibrous nonunion. Half of patients with CPT are affected by the multisystemic genetic disorder neurofibromatosis type 1 (NF1) caused by mutations in the NF1 tumor suppressor gene, a negative regulator of RAS-mitogen-activated protein kinase (MAPK) signaling pathway. Here, we analyzed patients with CPT and Prss56-Nf1 knockout mice to elucidate the pathogenic mechanisms of CPT-related fibrous nonunion and explored a pharmacological approach to treat CPT. We identified NF1-deficient Schwann cells and skeletal stem/progenitor cells (SSPCs) in pathological periosteum as affected cell types driving fibrosis. Whereas NF1-deficient SSPCs adopted a fibrotic fate, NF1-deficient Schwann cells produced critical paracrine factors including transforming growth factor-ß and induced fibrotic differentiation of wild-type SSPCs. To counteract the elevated RAS-MAPK signaling in both NF1-deficient Schwann cells and SSPCs, we used MAPK kinase (MEK) and Src homology 2 containing protein tyrosine phosphatase 2 (SHP2) inhibitors. Combined MEK-SHP2 inhibition in vivo prevented fibrous nonunion in the Prss56-Nf1 knockout mouse model, providing a promising therapeutic strategy for the treatment of fibrous nonunion in CPT.
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Ratones Noqueados , Neurofibromina 1 , Proteína Tirosina Fosfatasa no Receptora Tipo 11 , Seudoartrosis , Células de Schwann , Animales , Femenino , Humanos , Masculino , Ratones , Diferenciación Celular/efectos de los fármacos , Fibrosis , Quinasas de Proteína Quinasa Activadas por Mitógenos/metabolismo , Quinasas de Proteína Quinasa Activadas por Mitógenos/antagonistas & inhibidores , Neurofibromatosis 1/patología , Neurofibromatosis 1/metabolismo , Neurofibromatosis 1/complicaciones , Neurofibromina 1/metabolismo , Neurofibromina 1/genética , Proteína Tirosina Fosfatasa no Receptora Tipo 11/metabolismo , Proteína Tirosina Fosfatasa no Receptora Tipo 11/antagonistas & inhibidores , Seudoartrosis/patología , Seudoartrosis/metabolismo , Seudoartrosis/congénito , Células de Schwann/metabolismo , Células de Schwann/efectos de los fármacos , Células de Schwann/patología , Células Madre/metabolismo , Células Madre/efectos de los fármacos , Tibia/patologíaRESUMEN
Histiocytic sarcoma is a rare neoplasm of mature histiocytes with an aggressive clinical course and poor response to treatment. Primary gastric histiocytic sarcoma is rarer and just reported sporadically.Histiocytic sarcoma is a rare neoplasm of mature histiocytes with an aggressive clinical course and poor response to treatment. Primary gastric histiocytic sarcoma is rarer and just reported sporadically. A case of a 71-year-old female admitted with a one-year history of upper abdominal pain exacerbated after meals. After CT scans revealed a bulged mass at the lesser curvature of the gastric body, the patient underwent endoscopic submucosal dissection. Microscopically, non-cohesive neoplastic cells diffusely infiltrated lamina propria and submucosa, and diffusely expressed LCA, CD4, CD163, CD68 (KP1), Cyclin D1, Lysozyme, and Vimentin. PD-L1 (22CS) expression evaluated as CPS 60. The final pathological diagnosis was gastric histiocytic sarcoma. Subsequently, next-generation sequencing identified a nonsense mutation in exon 21 of NF1 gene [c.2446C > T (p.R816*)] and the TUBB3 gene amplification (copy number: 4.55). The patient refused further treatment and died of the tumor half a year later. This case broadens the spectrum of differential diagnosis of gastric cancer and emphasizes the value of immunohistochemical and molecular tests in the accurate diagnosis of histiocytic sarcoma. Furthermore, we performed literature review of 11 cases of gastric histiocytic sarcoma so as to strengthen the understanding of the clinicopathologic features, treatment, and prognosis.
Asunto(s)
Sarcoma Histiocítico , Neurofibromina 1 , Neoplasias Gástricas , Tubulina (Proteína) , Humanos , Femenino , Neoplasias Gástricas/genética , Neoplasias Gástricas/patología , Neoplasias Gástricas/diagnóstico , Neoplasias Gástricas/cirugía , Sarcoma Histiocítico/genética , Sarcoma Histiocítico/diagnóstico , Sarcoma Histiocítico/patología , Sarcoma Histiocítico/cirugía , Anciano , Neurofibromina 1/genética , Tubulina (Proteína)/genética , Amplificación de Genes , Mutación , Secuenciación de Nucleótidos de Alto RendimientoRESUMEN
Neurofibromatosis Type I (NF1) is a rare genetic disorder. NF1 patients frequently develop a benign tumor in peripheral nerve plexuses called plexiform neurofibroma. In the past two decades, tissue-specific Nf1 knockout mouse models were developed using commercially available tissue-specific Cre recombinase and the Nf1 flox mice to mimic neurofibroma development. However, these models develop para-spinal neurofibroma, recapitulating a rare type of neurofibroma found in NF1 patients. The NPcis mouse model developed a malignant version of neurofibroma called malignant peripheral nerve sheath tumor (MPNST) within 3 to 6 months but intriguingly without apparent benign precursor lesion. Here, we revisited the NPcis model and discovered that about 20% display clinical signs similar to Nf1 tissue-specific knockout mice models. However, a systematic histological analysis could not explain the clinical signs we observed although we noticed lesions reminiscent of a neurofibroma in a peripheral nerve, a cutaneous neurofibroma, and para-spinal neurofibroma on rare occasions in NPcis mice. We also observed that 10% of the mice developed a malignant peripheral nerve sheath tumor (MPNST) spontaneously, coinciding with their earring tag identification. Strikingly, half of the sciatic nerves from NPcis mice developed plexiform neurofibroma within 1-6 months when intentionally injured. Thus, we provided a procedure to turn the widely used NPcis sarcoma model into a model recapitulating plexiform neurofibroma.
Asunto(s)
Modelos Animales de Enfermedad , Neurofibroma Plexiforme , Animales , Neurofibroma Plexiforme/patología , Ratones , Nervio Ciático/patología , Ratones Noqueados , Neurofibromatosis 1/patología , Neurofibromatosis 1/genética , Neurofibromina 1/genéticaRESUMEN
NF1 microdeletion syndrome, accounting for 5-11% of NF1 patients, is caused by a deletion in the NF1 region and it is generally characterized by a severe phenotype. Although 70% of NF1 microdeletion patients presents the same 1.4 Mb type-I deletion, some patients may show additional clinical features. Therefore, the contribution of several pathogenic mechanisms, besides haploinsufficiency of some genes within the deletion interval, is expected and needs to be defined. We investigated an altered expression of deletion flanking genes by qPCR in patients with type-1 NF1 deletion, compared to healthy donors, possibly contributing to the clinical traits of NF1 microdeletion syndrome. In addition, the 1.4-Mb deletion leads to changes in the 3D chromatin structure in the 17q11.2 region. Specifically, this deletion alters DNA-DNA interactions in the regions flanking the breakpoints, as demonstrated by our 4C-seq analysis. This alteration likely causes position effect on the expression of deletion flanking genes.Interestingly, 4C-seq analysis revealed that in microdeletion patients, an interaction was established between the RHOT1 promoter and the SLC6A4 gene, which showed increased expression. We performed NGS on putative modifier genes, and identified two "likely pathogenic" rare variants in RAS pathway, possibly contributing to incidental phenotypic features.This study provides new insights into understanding the pathogenesis of NF1 microdeletion syndrome and suggests a novel pathomechanism that contributes to the expression phenotype in addition to haploinsufficiency of genes located within the deletion.This is a pivotal approach that can be applied to unravel microdeletion syndromes, improving precision medicine, prognosis and patients' follow-up.
Asunto(s)
Deleción Cromosómica , Epigénesis Genética , Haploinsuficiencia , Neurofibromatosis 1 , Humanos , Neurofibromatosis 1/genética , Femenino , Masculino , Neurofibromina 1/genética , Cromosomas Humanos Par 17/genética , Fenotipo , Niño , Regiones Promotoras GenéticasRESUMEN
Cognitive or motor impairment is common among individuals with neurofibromatosis type 1 (NF1), an autosomal dominant tumor-predisposition disorder. As many as 70% of children with NF1 report difficulties with spatial/working memory, attention, executive function, and fine motor movements. In contrast to the utilization of various Nf1 mouse models, here we employ an NF1+/ex42del miniswine model to evaluate the mechanisms and characteristics of these presentations, taking advantage of a large animal species more like human anatomy and physiology. The prefrontal lobe, anterior cingulate, and hippocampus from NF1+/ex42del and wild-type miniswine were examined longitudinally, revealing abnormalities in mature oligodendrocytes and astrocytes, and microglial activation over time. Imbalances in GABA: Glutamate ratios and GAD67 expression were observed in the hippocampus and motor cortex, supporting the role of disruption in inhibitory neurotransmission in NF1 cognitive impairment and motor dysfunction. Moreover, NF1+/ex42del miniswine demonstrated slower and shorter steps, indicative of a balance-preserving response commonly observed in NF1 patients, and progressive memory and learning impairments. Collectively, our findings affirm the effectiveness of NF1+/ex42del miniswine as a valuable resource for assessing cognitive and motor impairments associated with NF1, investigating the involvement of specific neural circuits and glia in these processes, and evaluating potential therapeutic interventions.
Asunto(s)
Modelos Animales de Enfermedad , Neurofibromatosis 1 , Animales , Neurofibromatosis 1/fisiopatología , Neurofibromatosis 1/complicaciones , Neurofibromatosis 1/metabolismo , Ratones , Neurofibromina 1/genética , Neurofibromina 1/metabolismo , Conducta Animal , Masculino , Hipocampo/patología , Hipocampo/metabolismo , Disfunción Cognitiva/etiología , Disfunción Cognitiva/fisiopatología , Oligodendroglía/metabolismo , Oligodendroglía/patología , Humanos , Astrocitos/metabolismo , Astrocitos/patología , FemeninoRESUMEN
Optic pathway gliomas (OPGs) are most predominant pilocytic astrocytomas, which are typically diagnosed within the first decade of life. The majority of affected children with OPGs also present with neurofibromatosis type 1 (NF1), the most common tumor predisposition syndrome. OPGs in individuals with NF1 primarily affect the optic pathway and lead to visual disturbance. However, it is challenging to assess risk in asymptomatic patients without valid biomarkers. On the other hand, for symptomatic patients, there is still no effective treatment to prevent or recover vision loss. Therefore, this review summarizes current knowledge regarding the pathogenesis of NF1-associated OPGs (NF1-OPGs) from preclinical studies to seek potential prognostic markers and therapeutic targets. First, the loss of the NF1 gene activates 3 distinct Ras effector pathways, including the PI3K/AKT/mTOR pathway, the MEK/ERK pathway, and the cAMP pathway, which mediate glioma tumorigenesis. Meanwhile, non-neoplastic cells from the tumor microenvironment (microglia, T cells, neurons, etc.) also contribute to gliomagenesis via various soluble factors. Subsequently, we investigated potential genetic risk factors, molecularly targeted therapies, and neuroprotective strategies for tumor prevention and vision recovery. Last, potential directions and promising preclinical models of NF1-OPGs are presented for further research. On the whole, NF1-OPGs develop as a result of the interaction between glioma cells and the tumor microenvironment. Developing effective treatments require a better understanding of tumor molecular characteristics, as well as multistage interventions targeting both neoplastic cells and non-neoplastic cells.
Asunto(s)
Neurofibromatosis 1 , Glioma del Nervio Óptico , Humanos , Neurofibromatosis 1/complicaciones , Neurofibromatosis 1/genética , Glioma del Nervio Óptico/terapia , Glioma del Nervio Óptico/genética , Factores de Riesgo , Animales , Neurofibromina 1/genética , Neoplasias del Nervio Óptico/terapia , Neoplasias del Nervio Óptico/genéticaRESUMEN
OBJECTIVE: Anaplastic thyroid carcinoma (ATC) is considered a very aggressive carcinoma and has been difficult to treat with therapeutic strategies. This study examines the landscape of genomic alteration in ATC, including the BRAF V600E mutation, and its clinical implications. DESIGN, PATIENTS AND MESUREMENT: A retrospective observational study was conducted using collected at the Center for Cancer Genomics and Advanced Therapeutics (C-CAT) in Japan, utilizing comprehensive genomic profiling data from 102 ATC cases. Additionally, AACR-GENIE data from 267 cases were analysed for validation. Statistical methods, including the conditional Kendall tau statistic and χ2 tests, were employed for survival analysis and gene mutation comparisons. RESULTS: Among 102 ATCs, BRAF, RAS, and other driver mutations were found in 83 cases (81.2%). The prevalence of BRAF V600E mutations was as high as 60%. Co-mutation analysis identified different genomic profiles in the BRAF, RAS, and wild-type groups. Despite the diverse molecular backgrounds, no significant differences in clinical variables and overall survival were observed. The analysis considering left-side amputation suggested that RAS mutations had a poorer prognosis. In the BRAF/RAS wild-type group, FGFR1 and NF1 were identified as driver mutations, with an accumulation of copy number variations and less TERT promoter mutations. This molecular subgrouping was also supported by the AACR-GENIE data. CONCLUSIONS: Comprehensive genomic analysis of ATC in Japan revealed distinct molecular subgroups, highlighting the importance of BRAF V600E mutations, particularly V600E, as potential therapeutic targets and suggest the relevance of tailor-made therapeutic strategies based on genomic profiling.