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International Journal of Molecular... May 2021Neurofibromatosis (NF) is a neurocutaneous syndrome characterized by the development of tumors of the central or peripheral nervous system including the brain, spinal... (Review)
Review
Neurofibromatosis (NF) is a neurocutaneous syndrome characterized by the development of tumors of the central or peripheral nervous system including the brain, spinal cord, organs, skin, and bones. There are three types of NF: NF1 accounting for 96% of all cases, NF2 in 3%, and schwannomatosis (SWN) in <1%. The NF1 gene is located on chromosome 17q11.2, which encodes for a tumor suppressor protein, neurofibromin, that functions as a negative regulator of Ras/MAPK and PI3K/mTOR signaling pathways. The NF2 gene is identified on chromosome 22q12, which encodes for merlin, a tumor suppressor protein related to ezrin-radixin-moesin that modulates the activity of PI3K/AKT, Raf/MEK/ERK, and mTOR signaling pathways. In contrast, molecular insights on the different forms of SWN remain unclear. Inactivating mutations in the tumor suppressor genes SMARCB1 and LZTR1 are considered responsible for a majority of cases. Recently, treatment strategies to target specific genetic or molecular events involved in their tumorigenesis are developed. This study discusses molecular pathways and related targeted therapies for NF1, NF2, and SWN and reviews recent clinical trials which involve NF patients.
Topics: Animals; Biomarkers, Tumor; Clinical Trials as Topic; Disease Models, Animal; Disease Susceptibility; Genes, Neurofibromatosis 1; Genes, Neurofibromatosis 2; Genetic Predisposition to Disease; Humans; Models, Biological; Molecular Targeted Therapy; Mutation; Neurilemmoma; Neurofibromatoses; Neurofibromatosis 1; Neurofibromatosis 2; Protein Kinase Inhibitors; Skin Neoplasms; Treatment Outcome
PubMed: 34072574
DOI: 10.3390/ijms22115850 -
Genetics in Medicine : Official Journal... Sep 2022Neurofibromatosis type 2 (NF2) and schwannomatosis (SWN) are genetically distinct tumor predisposition syndromes with overlapping phenotypes. We sought to update the...
PURPOSE
Neurofibromatosis type 2 (NF2) and schwannomatosis (SWN) are genetically distinct tumor predisposition syndromes with overlapping phenotypes. We sought to update the diagnostic criteria for NF2 and SWN by incorporating recent advances in genetics, ophthalmology, neuropathology, and neuroimaging.
METHODS
We used a multistep process, beginning with a Delphi method involving global disease experts and subsequently involving non-neurofibromatosis clinical experts, patients, and foundations/patient advocacy groups.
RESULTS
We reached consensus on the minimal clinical and genetic criteria for diagnosing NF2 and SWN. These criteria incorporate mosaic forms of these conditions. In addition, we recommend updated nomenclature for these disorders to emphasize their phenotypic overlap and to minimize misdiagnosis with neurofibromatosis type 1.
CONCLUSION
The updated criteria for NF2 and SWN incorporate clinical features and genetic testing, with a focus on using molecular data to differentiate the 2 conditions. It is likely that continued refinement of these new criteria will be necessary as investigators study the diagnostic properties of the revised criteria and identify new genes associated with SWN. In the revised nomenclature, the term "neurofibromatosis 2" has been retired to improve diagnostic specificity.
Topics: Consensus; Humans; Neurilemmoma; Neurofibromatoses; Neurofibromatosis 1; Neurofibromatosis 2; Skin Neoplasms
PubMed: 35674741
DOI: 10.1016/j.gim.2022.05.007 -
Neuro-oncology Jan 2020The level of evidence to provide treatment recommendations for vestibular schwannoma is low compared with other intracranial neoplasms. Therefore, the vestibular...
The level of evidence to provide treatment recommendations for vestibular schwannoma is low compared with other intracranial neoplasms. Therefore, the vestibular schwannoma task force of the European Association of Neuro-Oncology assessed the data available in the literature and composed a set of recommendations for health care professionals. The radiological diagnosis of vestibular schwannoma is made by magnetic resonance imaging. Histological verification of the diagnosis is not always required. Current treatment options include observation, surgical resection, fractionated radiotherapy, and radiosurgery. The choice of treatment depends on clinical presentation, tumor size, and expertise of the treating center. In small tumors, observation has to be weighed against radiosurgery, in large tumors surgical decompression is mandatory, potentially followed by fractionated radiotherapy or radiosurgery. Except for bevacizumab in neurofibromatosis type 2, there is no role for pharmacotherapy.
Topics: Humans; Neuroma, Acoustic
PubMed: 31504802
DOI: 10.1093/neuonc/noz153 -
Neurosurgery Feb 2021Neoplasms of the peripheral nervous system represent a heterogenous group with a wide spectrum of morphological features and biological potential. They range from benign... (Review)
Review
Neoplasms of the peripheral nervous system represent a heterogenous group with a wide spectrum of morphological features and biological potential. They range from benign and curable by complete excision (schwannoma and soft tissue perineurioma) to benign but potentially aggressive at the local level (plexiform neurofibroma) to the highly malignant (malignant peripheral nerve sheath tumors [MPNST]). In this review, we discuss the diagnostic and pathologic features of common peripheral nerve sheath tumors, particularly those that may be encountered in the intracranial compartment or in the spine and paraspinal region. The discussion will cover schwannoma, neurofibroma, atypical neurofibromatous neoplasms of uncertain biological potential, intraneural and soft tissue perineurioma, hybrid nerve sheath tumors, MPNST, and the recently renamed enigmatic tumor, malignant melanotic nerve sheath tumor, formerly referred to as melanotic schwannoma. We also discuss the diagnostic relevance of these neoplasms to specific genetic and familial syndromes of nerve, including neurofibromatosis 1, neurofibromatosis 2, and schwannomatosis. In addition, we discuss updates in our understanding of the molecular alterations that represent key drivers of these neoplasms, including neurofibromatosis type 1 and type 2, SMARCB1, LZTR1, and PRKAR1A loss, as well as the acquisition of CDKN2A/B mutations and alterations in the polycomb repressor complex members (SUZ12 and EED) in the malignant progression to MPNST. In summary, this review covers practical aspects of pathologic diagnosis with updates relevant to neurosurgical practice.
Topics: Animals; Humans; Nerve Sheath Neoplasms; Neurilemmoma; Neurofibroma; Neurofibromatoses; Peripheral Nerves; Peripheral Nervous System Neoplasms; Skin Neoplasms; Transcription Factors
PubMed: 33588442
DOI: 10.1093/neuros/nyab021 -
International Journal of Molecular... May 2022Vestibular schwannoma (VS) is a benign tumor that originates from Schwann cells in the vestibular component. Surgical treatment for VS has gradually declined over the... (Review)
Review
Vestibular schwannoma (VS) is a benign tumor that originates from Schwann cells in the vestibular component. Surgical treatment for VS has gradually declined over the past few decades, especially for small tumors. Gamma knife radiosurgery has become an accepted treatment for VS, with a high rate of tumor control. For neurofibromatosis type 2 (NF2)-associated VS resistant to radiotherapy, vascular endothelial growth factor (VEGF)-A/VEGF receptor (VEGFR)-targeted therapy (e.g., bevacizumab) may become the first-line therapy. Recently, a clinical trial using a VEGFR1/2 peptide vaccine was also conducted in patients with progressive NF2-associated schwannomas, which was the first immunotherapeutic approach for NF2 patients. Targeted therapies for the gene product of SH3PXD2A-HTRA1 fusion may be effective for sporadic VS. Several protein kinase inhibitors could be supportive to prevent tumor progression because merlin inhibits signaling by tyrosine receptor kinases and the activation of downstream pathways, including the Ras/Raf/MEK/ERK and PI3K/Akt/mTORC1 pathways. Tumor-microenvironment-targeted therapy may be supportive for the mainstays of management. The tumor-associated macrophage is the major component of immunosuppressive cells in schwannomas. Here, we present a critical overview of targeted therapies for VS. Multimodal therapy is required to manage patients with refractory VS.
Topics: High-Temperature Requirement A Serine Peptidase 1; Humans; Neurilemmoma; Neurofibromatosis 2; Neuroma, Acoustic; Phosphatidylinositol 3-Kinases; Tumor Microenvironment; Vascular Endothelial Growth Factor A
PubMed: 35628268
DOI: 10.3390/ijms23105462 -
The Pan African Medical Journal 2021
Topics: Humans; Neurilemmoma; Neurofibroma; Spinal Cord Neoplasms
PubMed: 34527162
DOI: 10.11604/pamj.2021.39.146.30169 -
European Journal of Human Genetics :... Jul 2022A Guideline Group (GG) was convened from multiple specialties and patients to develop the first comprehensive schwannomatosis guideline. The GG undertook thorough...
A Guideline Group (GG) was convened from multiple specialties and patients to develop the first comprehensive schwannomatosis guideline. The GG undertook thorough literature review and wrote recommendations for treatment and surveillance. A modified Delphi process was used to gain approval for recommendations which were further altered for maximal consensus. Schwannomatosis is a tumour predisposition syndrome leading to development of multiple benign nerve-sheath non-intra-cutaneous schwannomas that infrequently affect the vestibulocochlear nerves. Two definitive genes (SMARCB1/LZTR1) have been identified on chromosome 22q centromeric to NF2 that cause schwannoma development by a 3-event, 4-hit mechanism leading to complete inactivation of each gene plus NF2. These genes together account for 70-85% of familial schwannomatosis and 30-40% of isolated cases in which there is considerable overlap with mosaic NF2. Craniospinal MRI is generally recommended from symptomatic diagnosis or from age 12-14 if molecularly confirmed in asymptomatic individuals whose relative has schwannomas. Whole-body MRI may also be deployed and can alternate with craniospinal MRI. Ultrasound scans are useful in limbs where typical pain is not associated with palpable lumps. Malignant-Peripheral-Nerve-Sheath-Tumour-MPNST should be suspected in anyone with rapidly growing tumours and/or functional loss especially with SMARCB1-related schwannomatosis. Pain (often intractable to medication) is the most frequent symptom. Surgical removal, the most effective treatment, must be balanced against potential loss of function of adjacent nerves. Assessment of patients' psychosocial needs should be assessed annually as well as review of pain/pain medication. Genetic diagnosis and counselling should be guided ideally by both blood and tumour molecular testing.
Topics: Adolescent; Child; Humans; Neurilemmoma; Neurofibromatoses; Pain; Skin Neoplasms; Transcription Factors
PubMed: 35361920
DOI: 10.1038/s41431-022-01086-x -
Brain : a Journal of Neurology Apr 2023Schwannoma tumours typically arise on the eighth cranial nerve and are mostly caused by loss of the tumour suppressor Merlin (NF2). There are no approved chemotherapies...
Schwannoma tumours typically arise on the eighth cranial nerve and are mostly caused by loss of the tumour suppressor Merlin (NF2). There are no approved chemotherapies for these tumours and the surgical removal of the tumour carries a high risk of damage to the eighth or other close cranial nerve tissue. New treatments for schwannoma and other NF2-null tumours such as meningioma are urgently required. Using a combination of human primary tumour cells and mouse models of schwannoma, we have examined the role of the Hippo signalling pathway in driving tumour cell growth. Using both genetic ablation of the Hippo effectors YAP and TAZ as well as novel TEAD palmitoylation inhibitors, we show that Hippo signalling may be successfully targeted in vitro and in vivo to both block and, remarkably, regress schwannoma tumour growth. In particular, successful use of TEAD palmitoylation inhibitors in a preclinical mouse model of schwannoma points to their potential future clinical use. We also identify the cancer stem cell marker aldehyde dehydrogenase 1A1 (ALDH1A1) as a Hippo signalling target, driven by the TAZ protein in human and mouse NF2-null schwannoma cells, as well as in NF2-null meningioma cells, and examine the potential future role of this new target in halting schwannoma and meningioma tumour growth.
Topics: Animals; Humans; Mice; Cell Proliferation; Meningeal Neoplasms; Meningioma; Neurilemmoma; Neurofibromin 2; YAP-Signaling Proteins; Transcriptional Coactivator with PDZ-Binding Motif Proteins; TEA Domain Transcription Factors
PubMed: 36148553
DOI: 10.1093/brain/awac342 -
Medicina 2021
Topics: Diagnosis, Differential; Humans; Neurilemmoma
PubMed: 33611262
DOI: No ID Found -
Oncogene Aug 2020Schwannomas are tumors of the peripheral nervous system, consisting of different cell types. These include tumorigenic Schwann cells, axons, macrophages, T cells,... (Review)
Review
Schwannomas are tumors of the peripheral nervous system, consisting of different cell types. These include tumorigenic Schwann cells, axons, macrophages, T cells, fibroblasts, blood vessels, and an extracellular matrix. All cell types involved constitute an intricate "tumor microenvironment" and play relevant roles in the development and progression of schwannomas. Although Nf2 tumor suppressor gene-deficient Schwann cells are the primary tumorigenic element and principle focus of current research efforts, evidence is accumulating regarding the contributory roles of other cell types in schwannoma pathology. In this review, we aim to provide an overview of intra- and intercellular mechanisms contributing to schwannoma formation. "Genes load the gun, environment pulls the trigger." -George A. Bray.
Topics: Animals; Disease Progression; Humans; Mice; Neurilemmoma
PubMed: 32616891
DOI: 10.1038/s41388-020-1374-5