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Báez-Flores J, Rodríguez-Martín M, Lacal J. The therapeutic potential of neurofibromin signaling pathways and binding partners. Commun Biol 2023; 6:436. [PMID: 37081086 PMCID: PMC10119308 DOI: 10.1038/s42003-023-04815-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 04/05/2023] [Indexed: 04/22/2023] Open
Abstract
Neurofibromin controls many cell processes, such as growth, learning, and memory. If neurofibromin is not working properly, it can lead to health problems, including issues with the nervous, skeletal, and cardiovascular systems and cancer. This review examines neurofibromin's binding partners, signaling pathways and potential therapeutic targets. In addition, it summarizes the different post-translational modifications that can affect neurofibromin's interactions with other molecules. It is essential to investigate the molecular mechanisms that underlie neurofibromin variants in order to provide with functional connections between neurofibromin and its associated proteins for possible therapeutic targets based on its biological function.
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Affiliation(s)
- Juan Báez-Flores
- Laboratory of Functional Genetics of Rare Diseases, Department of Microbiology and Genetics, University of Salamanca (USAL), 37007, Salamanca, Spain
- Institute of Biomedical Research of Salamanca (IBSAL), 37007, Salamanca, Spain
| | - Mario Rodríguez-Martín
- Laboratory of Functional Genetics of Rare Diseases, Department of Microbiology and Genetics, University of Salamanca (USAL), 37007, Salamanca, Spain
- Institute of Biomedical Research of Salamanca (IBSAL), 37007, Salamanca, Spain
| | - Jesus Lacal
- Laboratory of Functional Genetics of Rare Diseases, Department of Microbiology and Genetics, University of Salamanca (USAL), 37007, Salamanca, Spain.
- Institute of Biomedical Research of Salamanca (IBSAL), 37007, Salamanca, Spain.
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2
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Wu T, Yang H, Xu L, Huang Q, He Q, Wu R, Mu YZ. NF1 Gene Novel Splicing Mutations in a Chinese Family with Neurofibromatosis Type 1: Case Series. Clin Cosmet Investig Dermatol 2022; 15:2345-2351. [PMCID: PMC9635557 DOI: 10.2147/ccid.s388045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 10/19/2022] [Indexed: 11/06/2022]
Affiliation(s)
- Ting Wu
- Department of Dermatology, the Affiliated Hospital of North Sichuan Medical College, Nanchong, People’s Republic of China
| | - Hao Yang
- Department of Dermatology, the Affiliated Hospital of North Sichuan Medical College, Nanchong, People’s Republic of China
| | - Liuli Xu
- Department of Dermatology, the Affiliated Hospital of North Sichuan Medical College, Nanchong, People’s Republic of China
| | - Qing Huang
- Department of Dermatology, the Affiliated Hospital of North Sichuan Medical College, Nanchong, People’s Republic of China
| | - Qi He
- Department of Dermatology, the Affiliated Hospital of North Sichuan Medical College, Nanchong, People’s Republic of China
| | - Rong Wu
- Pediatric department, Women’s and Children’s hospital of GaoPing District, Nanchong, People’s Republic of China
| | - Yun-Zhu Mu
- Department of Dermatology, the Affiliated Hospital of North Sichuan Medical College, Nanchong, People’s Republic of China
- Correspondence: Yun-Zhu Mu, Department of Dermatology, the Affiliated Hospital of North Sichuan Medical College, No. 1 Maoyuan South Road, Shunqing District, Nanchong, Sichuan Province, 63700, People’s Republic of China, Tel +8615984833231, Email
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3
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Mo J, Moye SL, McKay RM, Le LQ. Neurofibromin and suppression of tumorigenesis: beyond the GAP. Oncogene 2022; 41:1235-1251. [PMID: 35066574 PMCID: PMC9063229 DOI: 10.1038/s41388-021-02156-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 12/01/2021] [Accepted: 12/13/2021] [Indexed: 12/15/2022]
Abstract
Neurofibromatosis type 1 (NF1) is an autosomal dominant genetic disease and one of the most common inherited tumor predisposition syndromes, affecting 1 in 3000 individuals worldwide. The NF1 gene encodes neurofibromin, a large protein with RAS GTP-ase activating (RAS-GAP) activity, and loss of NF1 results in increased RAS signaling. Neurofibromin contains many other domains, and there is considerable evidence that these domains play a role in some manifestations of NF1. Investigating the role of these domains as well as the various signaling pathways that neurofibromin regulates and interacts with will provide a better understanding of how neurofibromin acts to suppress tumor development and potentially open new therapeutic avenues. In this review, we discuss what is known about the structure of neurofibromin, its interactions with other proteins and signaling pathways, its role in development and differentiation, and its function as a tumor suppressor. Finally, we discuss the latest research on potential therapeutics for neurofibromin-deficient neoplasms.
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Affiliation(s)
- Juan Mo
- Department of Dermatology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390-9069, USA
| | - Stefanie L. Moye
- Department of Dermatology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390-9069, USA
| | - Renee M. McKay
- Department of Dermatology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390-9069, USA
| | - Lu Q. Le
- Department of Dermatology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390-9069, USA,Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390-9069, USA,UTSW Comprehensive Neurofibromatosis Clinic, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390-9069, USA,Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390-9069, USA,O’Donnell Brain Institute, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390-9069, USA,Correspondence and requests for materials should be addressed to Lu Q. Le.
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4
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Splicing is an alternate oncogenic pathway activation mechanism in glioma. Nat Commun 2022; 13:588. [PMID: 35102191 PMCID: PMC8803922 DOI: 10.1038/s41467-022-28253-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 01/14/2022] [Indexed: 12/13/2022] Open
Abstract
High-grade diffuse glioma (HGG) is the leading cause of brain tumour death. While the genetic drivers of HGG have been well described, targeting these has thus far had little impact on survival suggesting other mechanisms are at play. Here we interrogate the alternative splicing landscape of pediatric and adult HGG through multi-omic analyses, uncovering an increased splicing burden compared with normal brain. The rate of recurrent alternative splicing in cancer drivers exceeds their mutation rate, a pattern that is recapitulated in pan-cancer analyses, and is associated with worse prognosis in HGG. We investigate potential oncogenicity by interrogating cancer pathways affected by alternative splicing in HGG; spliced cancer drivers include members of the RAS/MAPK pathway. RAS suppressor neurofibromin 1 is differentially spliced to a less active isoform in >80% of HGG downstream from REST upregulation, activating the RAS/MAPK pathway and reducing glioblastoma patient survival. Overall, our results identify non-mutagenic mechanisms by which cancers activate oncogenic pathways which need to accounted for in personalized medicine approaches. Targeting genetic drivers of high grade diffuse glioma (HGG) has not improved patient survival, suggesting the involvement of other mechanisms. Here, across cancer types, the authors identify increased alternative splicing burden in cancer drivers compared to mutation rate as an alternative mechanism for activation of oncogenic pathways such as RAS/MAPK.
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5
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Neurofibromatosis Type 1 Gene Alterations Define Specific Features of a Subset of Glioblastomas. Int J Mol Sci 2021; 23:ijms23010352. [PMID: 35008787 PMCID: PMC8745708 DOI: 10.3390/ijms23010352] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 12/14/2021] [Accepted: 12/24/2021] [Indexed: 02/08/2023] Open
Abstract
Neurofibromatosis type 1 (NF1) gene mutations or alterations occur within neurofibromatosis type 1 as well as in many different malignant tumours on the somatic level. In glioblastoma, NF1 loss of function plays a major role in inducing the mesenchymal (MES) subtype and, therefore defining the most aggressive glioblastoma. This is associated with an immune signature and mediated via the NF1–MAPK–FOSL1 axis. Specifically, increased invasion seems to be regulated via mutations in the leucine-rich domain (LRD) of the NF1 gene product neurofibromin. Novel targets for therapy may arise from neurofibromin deficiency-associated cellular mechanisms that are summarised in this review.
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6
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Wang W, Wei CJ, Cui XW, Li YH, Gu YH, Gu B, Li QF, Wang ZC. Impacts of NF1 Gene Mutations and Genetic Modifiers in Neurofibromatosis Type 1. Front Neurol 2021; 12:704639. [PMID: 34566848 PMCID: PMC8455870 DOI: 10.3389/fneur.2021.704639] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 07/15/2021] [Indexed: 12/26/2022] Open
Abstract
Neurofibromatosis type 1 (NF1) is a tumor predisposition genetic disorder that directly affects more than 1 in 3,000 individuals worldwide. It results from mutations of the NF1 gene and shows almost complete penetrance. NF1 patients show high phenotypic variabilities, including cafe-au-lait macules, freckling, or other neoplastic or non-neoplastic features. Understanding the underlying mechanisms of the diversities of clinical symptoms might contribute to the development of personalized healthcare for NF1 patients. Currently, studies have shown that the different types of mutations in the NF1 gene might correlate with this phenomenon. In addition, genetic modifiers are responsible for the different clinical features. In this review, we summarize different genetic mutations of the NF1 gene and related genetic modifiers. More importantly, we focus on the genotype–phenotype correlation. This review suggests a novel aspect to explain the underlying mechanisms of phenotypic heterogeneity of NF1 and provides suggestions for possible novel therapeutic targets to prevent or delay the onset and development of different manifestations of NF1.
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Affiliation(s)
- Wei Wang
- Department of Plastic and Reconstructive Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Cheng-Jiang Wei
- Department of Plastic and Reconstructive Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xi-Wei Cui
- Department of Plastic and Reconstructive Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yue-Hua Li
- Department of Plastic and Reconstructive Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yi-Hui Gu
- Department of Plastic and Reconstructive Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Bin Gu
- Department of Plastic and Reconstructive Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Qing-Feng Li
- Department of Plastic and Reconstructive Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zhi-Chao Wang
- Department of Plastic and Reconstructive Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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7
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Perez-Becerril C, Evans DG, Smith MJ. Pathogenic noncoding variants in the neurofibromatosis and schwannomatosis predisposition genes. Hum Mutat 2021; 42:1187-1207. [PMID: 34273915 DOI: 10.1002/humu.24261] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 06/16/2021] [Accepted: 07/13/2021] [Indexed: 11/11/2022]
Abstract
Neurofibromatosis type 1 (NF1), type 2 (NF2), and schwannomatosis are a group of autosomal dominant disorders that predispose to the development of nerve sheath tumors. Pathogenic variants (PVs) that cause NF1 and NF2 are located in the NF1 and NF2 loci, respectively. To date, most variants associated with schwannomatosis have been identified in the SMARCB1 and LZTR1 genes, and a missense variant in the DGCR8 gene was recently reported to predispose to schwannomas. In spite of the high detection rate for PVs in NF1 and NF2 (over 90% of non-mosaic germline variants can be identified by routine genetic screening) underlying PVs for a proportion of clinical cases remain undetected. A higher proportion of non-NF2 schwannomatosis cases have no detected PV, with PVs currently only identified in around 70%-86% of familial cases and 30%-40% of non-NF2 sporadic schwannomatosis cases. A number of variants of uncertain significance have been observed for each disorder, many of them located in noncoding, regulatory, or intergenic regions. Here we summarize noncoding variants in this group of genes and discuss their established or potential role in the pathogenesis of NF1, NF2, and schwannomatosis.
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Affiliation(s)
- Cristina Perez-Becerril
- Division of Evolution and Genomic Science, Manchester Centre for Genomic Medicine, St Mary's Hospital, Manchester Academic Health Science Centre, School of Biological Sciences, University of Manchester, Manchester, UK
| | - D Gareth Evans
- Division of Evolution and Genomic Science, Manchester Centre for Genomic Medicine, St Mary's Hospital, Manchester Academic Health Science Centre, School of Biological Sciences, University of Manchester, Manchester, UK
| | - Miriam J Smith
- Division of Evolution and Genomic Science, Manchester Centre for Genomic Medicine, St Mary's Hospital, Manchester Academic Health Science Centre, School of Biological Sciences, University of Manchester, Manchester, UK
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8
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Kwong HL, Tay YK, Tan EC. Case Report: Mosaicism of a novel nonsense variant in the neurofibromin gene underlies a mosaic generalized NF1 phenotype. F1000Res 2021; 10:148. [PMID: 34164111 PMCID: PMC8215559 DOI: 10.12688/f1000research.28052.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/23/2021] [Indexed: 11/20/2022] Open
Abstract
Neurofibromatosis 1 (NF1) is a neurocutaneous syndrome characterized by multiple café-au-lait macules, cutaneous neurofibromas or plexiform neurofibromas, iris Lisch nodules, axillary and inguinal freckling. Mosaicism in NF1 can either present as a generalized disease, or in a localized (segmental) manner. Mosaic generalized NF1 may have presentations that are similar to generalized NF1 or have a milder phenotype and hence may be under-recognised in clinical practice. We report a nonsense mutation in the NF1 gene in a 55-year old Chinese male with the mosaic generalized phenotype. He reported noticing increasing numbers of skin-colored papules over his face, neck, back and abdomen when he was about 40 years old. From both next-generation and Sanger sequencing data, the variant appeared to be mosaic and present at about 24%. It is in exon 39 and has not been reported in any database or published literature.
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Affiliation(s)
| | | | - Ene-Choo Tan
- KK Women's and Children's Hospital, Singapore, Singapore.,Paediatrics Academic Clinical Programme, SingHealth Duke-NUS Medical School, Singapore, Singapore
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9
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Using antisense oligonucleotides for the physiological modulation of the alternative splicing of NF1 exon 23a during PC12 neuronal differentiation. Sci Rep 2021; 11:3661. [PMID: 33574490 PMCID: PMC7878752 DOI: 10.1038/s41598-021-83152-w] [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: 05/08/2020] [Accepted: 01/29/2021] [Indexed: 01/11/2023] Open
Abstract
Neurofibromatosis Type 1 (NF1) is a genetic condition affecting approximately 1:3500 persons worldwide. The NF1 gene codes for neurofibromin protein, a GTPase activating protein (GAP) and a negative regulator of RAS. The NF1 gene undergoes alternative splicing of exon 23a (E23a) that codes for 21 amino acids placed at the center of the GAP related domain (GRD). E23a-containing type II neurofibromin exhibits a weaker Ras-GAP activity compared to E23a-less type I isoform. Exon E23a has been related with the cognitive impairment present in NF1 individuals. We designed antisense Phosphorodiamidate Morpholino Oligomers (PMOs) to modulate E23a alternative splicing at physiological conditions of gene expression and tested their impact during PC12 cell line neuronal differentiation. Results show that any dynamic modification of the natural ratio between type I and type II isoforms disturbed neuronal differentiation, altering the proper formation of neurites and deregulating both the MAPK/ERK and cAMP/PKA signaling pathways. Our results suggest an opposite regulation of these pathways by neurofibromin and the possible existence of a feedback loop sensing neurofibromin-related signaling. The present work illustrates the utility of PMOs to study alternative splicing that could be applied to other alternatively spliced genes in vitro and in vivo.
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10
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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: 62] [Impact Index Per Article: 15.5] [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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11
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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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12
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Riccardi C, Perrone L, Napolitano F, Sampaolo S, Melone MAB. Understanding the Biological Activities of Vitamin D in Type 1 Neurofibromatosis: New Insights into Disease Pathogenesis and Therapeutic Design. Cancers (Basel) 2020; 12:E2965. [PMID: 33066259 PMCID: PMC7602022 DOI: 10.3390/cancers12102965] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 09/18/2020] [Accepted: 10/08/2020] [Indexed: 02/07/2023] Open
Abstract
Vitamin D is a fat-soluble steroid hormone playing a pivotal role in calcium and phosphate homeostasis as well as in bone health. Vitamin D levels are not exclusively dependent on food intake. Indeed, the endogenous production-occurring in the skin and dependent on sun exposure-contributes to the majority amount of vitamin D present in the body. Since vitamin D receptors (VDRs) are ubiquitous and drive the expression of hundreds of genes, the interest in vitamin D has tremendously grown and its role in different diseases has been extensively studied. Several investigations indicated that vitamin D action extends far beyond bone health and calcium metabolism, showing broad effects on a variety of critical illnesses, including cancer, infections, cardiovascular and autoimmune diseases. Epidemiological studies indicated that low circulating vitamin D levels inversely correlate with cutaneous manifestations and bone abnormalities, clinical hallmarks of neurofibromatosis type 1 (NF1). NF1 is an autosomal dominant tumour predisposition syndrome causing significant pain and morbidity, for which limited treatment options are available. In this context, vitamin D or its analogues have been used to treat both skin and bone lesions in NF1 patients, alone or combined with other therapeutic agents. Here we provide an overview of vitamin D, its characteristic nutritional properties relevant for health benefits and its role in NF1 disorder. We focus on preclinical and clinical studies that demonstrated the clinical correlation between vitamin D status and NF1 disease, thus providing important insights into disease pathogenesis and new opportunities for targeted therapy.
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Affiliation(s)
- Claudia Riccardi
- Department of Chemical Sciences, University of Naples Federico II, via Cintia 21, I-80126 Naples, Italy;
- Department of Advanced Medical and Surgical Sciences, 2nd Division of Neurology, Center for Rare Diseases and InterUniversity Center for Research in Neurosciences, University of Campania Luigi Vanvitelli, via Sergio Pansini 5, I-80131 Naples, Italy; (L.P.); (F.N.); (S.S.)
| | - Lorena Perrone
- Department of Advanced Medical and Surgical Sciences, 2nd Division of Neurology, Center for Rare Diseases and InterUniversity Center for Research in Neurosciences, University of Campania Luigi Vanvitelli, via Sergio Pansini 5, I-80131 Naples, Italy; (L.P.); (F.N.); (S.S.)
| | - Filomena Napolitano
- Department of Advanced Medical and Surgical Sciences, 2nd Division of Neurology, Center for Rare Diseases and InterUniversity Center for Research in Neurosciences, University of Campania Luigi Vanvitelli, via Sergio Pansini 5, I-80131 Naples, Italy; (L.P.); (F.N.); (S.S.)
| | - Simone Sampaolo
- Department of Advanced Medical and Surgical Sciences, 2nd Division of Neurology, Center for Rare Diseases and InterUniversity Center for Research in Neurosciences, University of Campania Luigi Vanvitelli, via Sergio Pansini 5, I-80131 Naples, Italy; (L.P.); (F.N.); (S.S.)
| | - Mariarosa Anna Beatrice Melone
- Department of Advanced Medical and Surgical Sciences, 2nd Division of Neurology, Center for Rare Diseases and InterUniversity Center for Research in Neurosciences, University of Campania Luigi Vanvitelli, via Sergio Pansini 5, I-80131 Naples, Italy; (L.P.); (F.N.); (S.S.)
- Sbarro Institute for Cancer Research and Molecular Medicine, Department of Biology, Temple University, BioLife Building (015-00), 1900 North 12th Street, Philadelphia, PA 19122-6078, USA
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13
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Lou H, Zhai C, Gong L, Pan H, Pan H, Zhang Y, Yang M, Hu Z. NF1 germline mutation in a Chinese family with colon cancer. J Int Med Res 2020; 48:300060519896435. [PMID: 32814491 PMCID: PMC7444156 DOI: 10.1177/0300060519896435] [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] [Indexed: 12/24/2022] Open
Abstract
Colorectal cancer (CRC) is a leading cause of cancer death worldwide. Recent advances in genomic medicine have identified novel gene mutations that contribute to an increased risk of CRC. Here, we describe a diagnosis of colon cancer in a 63-year-old woman and also in her brother. Next-generation sequencing showed that both patients harbored a germline mutation in NF1. The female patient also carried co-mutations in KRAS and NRAS. Furthermore, the NF1 germline mutation was identified in a healthy offspring of the brother. The female patient received three cycles of bevacizumab plus capecitabine/oxaliplatin therapy and achieved stable disease of the primary lesion in the colon and partial response of metastasis in the right abdominal cavity. This study highlights the association of NF1 germline mutations with colon cancer.
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Affiliation(s)
- Haizhou Lou
- Department of Medical Oncology 1, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Chongya Zhai
- Department of Medical Oncology 1, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Liu Gong
- Department of Medical Oncology 1, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Hong Pan
- Department of Medical Oncology 1, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Hongming Pan
- Department of Medical Oncology 1, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | | | | | - Zimin Hu
- Department of Respiratory Disease, Cixi Sixth Hospital, Ningbo, China
- Zimin Hu, Department of Respiratory Disease, Cixi Sixth Hospital, 100 Youth Palace South Road, Ningbo 315300, China.
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14
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Yan W, Markegard E, Dharmaiah S, Urisman A, Drew M, Esposito D, Scheffzek K, Nissley DV, McCormick F, Simanshu DK. Structural Insights into the SPRED1-Neurofibromin-KRAS Complex and Disruption of SPRED1-Neurofibromin Interaction by Oncogenic EGFR. Cell Rep 2020; 32:107909. [PMID: 32697994 PMCID: PMC7437355 DOI: 10.1016/j.celrep.2020.107909] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 05/25/2020] [Accepted: 06/24/2020] [Indexed: 02/07/2023] Open
Abstract
Sprouty-related, EVH1 domain-containing (SPRED) proteins negatively regulate RAS/mitogen-activated protein kinase (MAPK) signaling following growth factor stimulation. This inhibition of RAS is thought to occur primarily through SPRED1 binding and recruitment of neurofibromin, a RasGAP, to the plasma membrane. Here, we report the structure of neurofibromin (GTPase-activating protein [GAP]-related domain) complexed with SPRED1 (EVH1 domain) and KRAS. The structure provides insight into how the membrane targeting of neurofibromin by SPRED1 allows simultaneous interaction with activated KRAS. SPRED1 and NF1 loss-of-function mutations occur across multiple cancer types and developmental diseases. Analysis of the neurofibromin-SPRED1 interface provides a rationale for mutations observed in Legius syndrome and suggests why SPRED1 can bind to neurofibromin but no other RasGAPs. We show that oncogenic EGFR(L858R) signaling leads to the phosphorylation of SPRED1 on serine 105, disrupting the SPRED1-neurofibromin complex. The structural, biochemical, and biological results provide new mechanistic insights about how SPRED1 interacts with neurofibromin and regulates active KRAS levels in normal and pathologic conditions.
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Affiliation(s)
- Wupeng Yan
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD 21701, USA
| | - Evan Markegard
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Srisathiyanarayanan Dharmaiah
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD 21701, USA
| | - Anatoly Urisman
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Matthew Drew
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD 21701, USA
| | - Dominic Esposito
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD 21701, USA
| | - Klaus Scheffzek
- Institute of Biological Chemistry, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Dwight V Nissley
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD 21701, USA
| | - Frank McCormick
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD 21701, USA; Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA 94158, USA.
| | - Dhirendra K Simanshu
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD 21701, USA.
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15
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Zheng Y, Qiu G, Dai H, Zhu C, Xue D, Ren Y. Two novel mutations of NF1 gene identified in Chinese patients with severe neurofibromatosis type 1. Indian J Dermatol Venereol Leprol 2020; 86:76-81. [PMID: 31868168 DOI: 10.4103/ijdvl.ijdvl_1037_18] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Yuxin Zheng
- Department of Dermatology, Second Affiliated Hospital, Zhejiang University School of Medicine; The Second Clinical Medical College, Zhejiang Chinese Medical University, Hangzhou, China
| | - Guiying Qiu
- Department of Dermatology, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Huatuo Dai
- Department of Dermatology, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Chengyao Zhu
- Department of Dermatology, Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu, Zhejiang, China
| | - Dan Xue
- Department of Plastic Surgery, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yunqing Ren
- Department of Dermatology, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
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16
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Lee S, Cieply B, Yang Y, Peart N, Glaser C, Chan P, Carstens RP. Esrp1-Regulated Splicing of Arhgef11 Isoforms Is Required for Epithelial Tight Junction Integrity. Cell Rep 2019; 25:2417-2430.e5. [PMID: 30485810 PMCID: PMC6371790 DOI: 10.1016/j.celrep.2018.10.097] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 09/10/2018] [Accepted: 10/25/2018] [Indexed: 12/19/2022] Open
Abstract
The epithelial-specific splicing regulators Esrp1 and Esrp2 are required for mammalian development, including establishment of epidermal barrier functions. However, the mechanisms by which Esrp ablation causes defects in epithelial barriers remain undefined. We determined that the ablation of Esrp1 and Esrp2 impairs epithelial tight junction (TJ) integrity through loss of the epithelial isoform of Rho GTP exchange factor Arhgef11. Arhgef11 is required for the maintenance of TJs via RhoA activation and myosin light chain (MLC) phosphorylation. Ablation or depletion of Esrp1/2 or Arhgef11 inhibits MLC phosphorylation and only the epithelial Arhgef11 isoform rescues MLC phosphorylation in Arhgef11 KO epithelial cells. Mesenchymal Arhgef11 transcripts contain a C-terminal exon that binds to PAK4 and inhibits RhoA activation byArhgef11. Deletion of the mesenchymal-specific Arhgef11 exon in Esrp1/2 KO epithelial cells using CRISPR/Cas9 restored TJ function, illustrating how splicing alterations can be mechanistically linked to disease phenotypes that result from impaired functions of splicing regulators.
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Affiliation(s)
- SungKyoung Lee
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Benjamin Cieply
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Yueqin Yang
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Natoya Peart
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Carl Glaser
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Patricia Chan
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Russ P Carstens
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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17
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LIU B, YANG Y, YAN K, CHEN M, WANG L, HUANG Y, QIAN Y, DONG M. [Genetic analysis and prenatal diagnosis of a sporadic family with neurofibromatosis type 1]. Zhejiang Da Xue Xue Bao Yi Xue Ban 2019; 48:367-372. [PMID: 31901038 PMCID: PMC8800689 DOI: 10.3785/j.issn.1008-9292.2019.08.03] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
OBJECTIVE To identify pathogenic mutation for a family with neurofibromatosis type 1(NF1) and provide prenatal diagnosis for them. METHODS Mutation analysis of the sporadic family with NF1 was performed with target captured next generation sequencing and Sanger sequencing. RNA samples were extracted from the lymphocytes of NF1 patient and her parents. RT-PCR and Sanger sequencing were performed to analyze the relative mRNA expression in the samples. Prenatal diagnosis of the pathogenic mutation was offered to the fetus. RESULTS A novel splicing mutation c.1260+4A>T in the NF1 gene was found in the proband of the family, but was not found in her parents.cDNA sequencing showed that 13 bases inserted into the 3' end of exon 11 in the NF1 gene lead to a frameshift mutation. Prenatal diagnosis suggested that the fetus did not carried the mutant. CONCLUSIONS The NF1: c.1260+4A>T mutation found in the NF1 patient is considered to be pathogenic, which provides information for family genetic counseling and prenatal diagnosis.
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Affiliation(s)
| | | | | | | | | | | | | | - Minyue DONG
- 董旻岳(1964—), 男, 博士, 主任医师, 博士生导师, 主要从事生殖遗传学研究; E-mail:
;
https://orcid.org/0000-0002-4344-7924
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18
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Cui Y, Morrison H. Construction of cloning-friendly minigenes for mammalian expression of full-length human NF1 isoforms. Hum Mutat 2018; 40:187-192. [DOI: 10.1002/humu.23681] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 10/23/2018] [Accepted: 11/06/2018] [Indexed: 01/17/2023]
Affiliation(s)
- Yan Cui
- Leibniz Institute on Aging, Fritz Lipmann Institute (FLI); Jena Germany
| | - Helen Morrison
- Leibniz Institute on Aging, Fritz Lipmann Institute (FLI); Jena Germany
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19
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Guo X, Zhao Y, Nguyen H, Liu T, Wang Z, Lou H. Quantitative Analysis of Alternative Pre-mRNA Splicing in Mouse Brain Sections Using RNA In Situ Hybridization Assay. J Vis Exp 2018. [PMID: 30199013 DOI: 10.3791/57889] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Alternative splicing (AS) occurs in more than 90% of human genes. The expression pattern of an alternatively spliced exon is often regulated in a cell type-specific fashion. AS expression patterns are typically analyzed by RT-PCR and RNA-seq using RNA samples isolated from a population of cells. In situ examination of AS expression patterns for a particular biological structure can be carried out by RNA in situ hybridization (ISH) using exon-specific probes. However, this particular use of ISH has been limited because alternative exons are generally too short to design exon-specific probes. In this report, the use of BaseScope, a recently developed technology that employs short antisense oligonucleotides in RNA ISH, is described to analyze AS expression patterns in mouse brain sections. Exon 23a of neurofibromatosis type 1 (Nf1) is used as an example to illustrate that short exon-exon junction probes exhibit robust hybridization signals with high specificity in RNA ISH analysis on mouse brain sections. More importantly, signals detected with exon inclusion- and skipping-specific probes can be used to reliably calculate the percent spliced in values of Nf1 exon 23a expression in different anatomical areas of a mouse brain. The experimental protocol and calculation method for AS analysis are presented. The results indicate that BaseScope provides a powerful new tool to assess AS expression patterns in situ.
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Affiliation(s)
- Xuan Guo
- Department of Genetics and Genome Sciences, Case Western Reserve University; Department of Endocrinology, Dongfang Hospital of Beijing University of Chinese Medicine
| | - Yiqing Zhao
- Department of Genetics and Genome Sciences, Case Western Reserve University; Case Comprehensive Cancer Center, Case Western Reserve University
| | - Hieu Nguyen
- Department of Genetics and Genome Sciences, Case Western Reserve University
| | - Tonghua Liu
- Department of Endocrinology, Dongfang Hospital of Beijing University of Chinese Medicine
| | - Zhenghe Wang
- Department of Genetics and Genome Sciences, Case Western Reserve University; Case Comprehensive Cancer Center, Case Western Reserve University
| | - Hua Lou
- Department of Genetics and Genome Sciences, Case Western Reserve University; Case Comprehensive Cancer Center, Case Western Reserve University; Center for RNA Science and Therapeutics, Case Western Reserve University;
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20
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Mao B, Chen S, Chen X, Yu X, Zhai X, Yang T, Li L, Wang Z, Zhao X, Zhang X. Clinical characteristics and spectrum of NF1 mutations in 12 unrelated Chinese families with neurofibromatosis type 1. BMC MEDICAL GENETICS 2018; 19:101. [PMID: 29914388 PMCID: PMC6006597 DOI: 10.1186/s12881-018-0615-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2018] [Accepted: 05/23/2018] [Indexed: 12/16/2022]
Abstract
BACKGROUND Neurofibromatosis type 1 (NF1) is a common autosomal dominant disorder caused by a heterozygous germline mutation in the tumor suppressor gene NF1. Because of the existence of highly homologous pseudogenes, the large size of the gene, and the heterogeneity of mutation types and positions, the detection of variations in NF1 is more difficult than that for an ordinary gene. METHODS In this study, we collected samples from 23 patients among 46 study participants from 12 unrelated Chinese families with NF1. We used a combination of Sanger sequencing, targeted next-generation sequencing, and multiplex ligation-dependent probe amplification to identify potential mutations of different types. RESULTS Seven recurrent mutations and four novel mutations were identified with the aforementioned methods, which were subsequently confirmed by either restriction fragment length polymorphism analysis or Sanger sequencing. Truncating mutations accounted for 73% (8/11) of all mutations identified. We also exhaustively investigated the clinical manifestations of NF1 in patients via acquired pathography, photographs and follow-up. However, no clear genotype-phenotype correlation has been found to date. CONCLUSION In conclusion, the novel mutations identified broaden the spectrum of NF1 mutations in Chinese; however, obvious correlations between genotype and phenotype were not observed in this study.
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Affiliation(s)
- Bin Mao
- Department of Medical Genetics, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & School of Basic Medicine, Peking Union Medical College, Beijing, 100005, China
| | - Siyu Chen
- Department of Medical Genetics, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & School of Basic Medicine, Peking Union Medical College, Beijing, 100005, China
| | - Xin Chen
- Department of Medical Genetics, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & School of Basic Medicine, Peking Union Medical College, Beijing, 100005, China
| | - Xiumei Yu
- Department of Obstetrics and Gynecology, the First Affiliated Hospital of Hebei North University, Zhangjiakou, 075061, China
| | - Xiaojia Zhai
- Department of Medical Genetics, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & School of Basic Medicine, Peking Union Medical College, Beijing, 100005, China
| | - Tao Yang
- Department of Medical Genetics, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & School of Basic Medicine, Peking Union Medical College, Beijing, 100005, China
| | - Lulu Li
- Department of Medical Genetics, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & School of Basic Medicine, Peking Union Medical College, Beijing, 100005, China
| | - Zheng Wang
- Department of Medical Genetics, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & School of Basic Medicine, Peking Union Medical College, Beijing, 100005, China
| | - Xiuli Zhao
- Department of Medical Genetics, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & School of Basic Medicine, Peking Union Medical College, Beijing, 100005, China.
| | - Xue Zhang
- Department of Medical Genetics, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & School of Basic Medicine, Peking Union Medical College, Beijing, 100005, China.
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21
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Allaway RJ, Gosline SJC, La Rosa S, Knight P, Bakker A, Guinney J, Le LQ. Cutaneous neurofibromas in the genomics era: current understanding and open questions. Br J Cancer 2018; 118:1539-1548. [PMID: 29695767 PMCID: PMC6008439 DOI: 10.1038/s41416-018-0073-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 02/24/2018] [Accepted: 03/08/2018] [Indexed: 02/07/2023] Open
Abstract
Cutaneous neurofibromas (cNF) are a nearly ubiquitous symptom of neurofibromatosis type 1 (NF1), a disorder with a broad phenotypic spectrum caused by germline mutation of the neurofibromatosis type 1 tumour suppressor gene (NF1). Symptoms of NF1 can include learning disabilities, bone abnormalities and predisposition to tumours such as cNFs, plexiform neurofibromas, malignant peripheral nerve sheath tumours and optic nerve tumours. There are no therapies currently approved for cNFs aside from elective surgery, and the molecular aetiology of cNF remains relatively uncharacterised. Furthermore, whereas the biallelic inactivation of NF1 in neoplastic Schwann cells is critical for cNF formation, it is still unclear which additional genetic, transcriptional, epigenetic, microenvironmental or endocrine changes are important. Significant inroads have been made into cNF understanding, including NF1 genotype–phenotype correlations in NF1 microdeletion patients, the identification of recurring somatic mutations, studies of cNF-invading mast cells and macrophages, and clinical trials of putative therapeutic targets such as mTOR, MEK and c-KIT. Despite these advances, several gaps remain in our knowledge of the associated pathogenesis, which is further hampered by a lack of translationally relevant animal models. Some of these questions may be addressed in part by the adoption of genomic analysis techniques. Understanding the aetiology of cNF at the genomic level may assist in the development of new therapies for cNF, and may also contribute to a greater understanding of NF1/RAS signalling in cancers beyond those associated with NF1. Here, we summarise the present understanding of cNF biology, including the pathogenesis, mutational landscape, contribution of the tumour microenvironment and endocrine signalling, and the historical and current state of clinical trials for cNF. We also highlight open access data resources and potential avenues for future research that leverage recently developed genomics-based methods in cancer research.
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Affiliation(s)
| | | | | | - Pamela Knight
- Children's Tumor Foundation, New York, NY, 10005, USA
| | | | | | - Lu Q Le
- Department of Dermatology, Simmons Comprehensive Cancer Center and the Neurofibromatosis Clinic, UT Southwestern Medical Center, Dallas, TX, 75390, USA.
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22
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Nguyen HT, Hinman MN, Guo X, Sharma A, Arakawa H, Luo G, Lou H. Neurofibromatosis type 1 alternative splicing is a key regulator of Ras/ERK signaling and learning behaviors in mice. Hum Mol Genet 2018; 26:3797-3807. [PMID: 28934393 DOI: 10.1093/hmg/ddx264] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 06/28/2017] [Indexed: 01/10/2023] Open
Abstract
Appropriate activation of the Ras/extracellular signal-regulated kinase (ERK) protein signaling cascade within the brain is crucial for optimal learning and memory. One key regulator of this cascade is the Nf1 Ras GTPase activating protein (RasGAP), which attenuates Ras/ERK signaling by converting active Ras is bound to guanosine triphosphate, activating Ras into inactive Ras is bound to guanosine diphosphate, inactivating Ras. A previous study using embryonic stem cells and embryonic stem cell-derived neurons indicated that Nf1 RasGAP activity is modulated by the highly regulated alternative splicing of Nf1 exon 23a. In this study, we generated Nf123aIN/23aIN mice, in which the splicing signals surrounding Nf1 exon 23a were manipulated to increase exon inclusion. Nf123aIN/23aIN mice are viable and exon 23a inclusion approaches 100% in all tissues, including the brain, where the exon is normally almost completely skipped. Ras activation and phosphorylation of ERK1/2 downstream of Ras are both greatly increased in Nf123aIN/23aIN mouse brain lysates, confirming that exon 23a inclusion inhibits Nf1 RasGAP activity in vivo as it does in cultured cells. Consistent with the finding of altered Ras/ERK signaling in the brain, Nf123aIN/23aIN mice showed specific deficits in learning and memory compared with Nf1+/+ mice. Nf123aIN/23aIN mice performed poorly on the T-maze and Morris water maze tests, which measure short- and long-term spatial memory, respectively. In addition, Nf123aIN/23aIN mice showed abnormally elevated context-dependent fear and a diminished ability to extinguish a cued fear response, indicating defective associative fear learning. Therefore, the regulated alternative splicing of Nf1 is an important mechanism for fine-tuning Ras/ERK signaling as well as learning and memory in mice.
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Affiliation(s)
| | | | - Xuan Guo
- Department of Genetics and Genome Sciences
| | | | | | - Guangbin Luo
- Department of Genetics and Genome Sciences.,Case Comprehensive Cancer Center
| | - Hua Lou
- Department of Genetics and Genome Sciences.,Case Comprehensive Cancer Center.,Center for RNA Molecular Biology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
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23
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Sharma A, Nguyen H, Cai L, Lou H. Histone hyperacetylation and exon skipping: a calcium-mediated dynamic regulation in cardiomyocytes. Nucleus 2016; 6:273-8. [PMID: 26325491 DOI: 10.1080/19491034.2015.1081324] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
In contrast to cell type-specific pre-mRNA alternative splicing, mechanisms controlling activity-dependent alternative splicing is under-studied and not well understood. In a recent study, we conducted a comprehensive analysis of calcium-mediated mechanism that regulates alternative exon skipping in mouse cardiomyocytes. Our results reveal a strong link between histone hyperacetylation and skipping of cassette exons, and provide support to the kinetic coupling model of the epigenetic regulation of alternative splicing at the chromatin level.
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Affiliation(s)
- Alok Sharma
- a Department of Genetics and Genome Sciences ; Case Western Reserve University ; Cleveland , OH USA
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24
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Ratner N, Miller SJ. A RASopathy gene commonly mutated in cancer: the neurofibromatosis type 1 tumour suppressor. Nat Rev Cancer 2015; 15:290-301. [PMID: 25877329 PMCID: PMC4822336 DOI: 10.1038/nrc3911] [Citation(s) in RCA: 298] [Impact Index Per Article: 33.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Neurofibromatosis type 1 (NF1) is a common genetic disorder that predisposes affected individuals to tumours. The NF1 gene encodes a RAS GTPase-activating protein called neurofibromin and is one of several genes that (when mutant) affect RAS-MAPK signalling, causing related diseases collectively known as RASopathies. Several RASopathies, beyond NF1, are cancer predisposition syndromes. Somatic NF1 mutations also occur in 5-10% of human sporadic cancers and may contribute to resistance to therapy. To highlight areas for investigation in RASopathies and sporadic tumours with NF1 mutations, we summarize current knowledge of NF1 disease, the NF1 gene and neurofibromin, neurofibromin signalling pathways and recent developments in NF1 therapeutics.
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Affiliation(s)
- Nancy Ratner
- Division of Experimental Hematology and Cancer Biology, Cancer and Blood Diseases Institute, Cincinnati Children's Hospital, 3333 Burnet Avenue, Cincinnati, Ohio 45229, USA
| | - Shyra J Miller
- Division of Experimental Hematology and Cancer Biology, Cancer and Blood Diseases Institute, Cincinnati Children's Hospital, 3333 Burnet Avenue, Cincinnati, Ohio 45229, USA
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25
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Sharma A, Nguyen H, Geng C, Hinman MN, Luo G, Lou H. Calcium-mediated histone modifications regulate alternative splicing in cardiomyocytes. Proc Natl Acad Sci U S A 2014; 111:E4920-8. [PMID: 25368158 PMCID: PMC4246288 DOI: 10.1073/pnas.1408964111] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
In cardiomyocytes, calcium is known to control gene expression at the level of transcription, whereas its role in regulating alternative splicing has not been explored. Here we report that, in mouse primary or embryonic stem cell-derived cardiomyocytes, increased calcium levels induce robust and reversible skipping of several alternative exons from endogenously expressed genes. Interestingly, we demonstrate a calcium-mediated splicing regulatory mechanism that depends on changes of histone modifications. Specifically, the regulation occurs through changes in calcium-responsive kinase activities that lead to alterations in histone modifications and subsequent changes in the transcriptional elongation rate and exon skipping. We demonstrate that increased intracellular calcium levels lead to histone hyperacetylation along the body of the genes containing calcium-responsive alternative exons by disrupting the histone deacetylase-to-histone acetyltransferase balance in the nucleus. Consequently, the RNA polymerase II elongation rate increases significantly on those genes, resulting in skipping of the alternative exons. These studies reveal a mechanism by which calcium-level changes in cardiomyocytes impact on the output of gene expression through altering alternative pre-mRNA splicing patterns.
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Affiliation(s)
| | | | - Cuiyu Geng
- Department of Genetics and Genome Sciences
| | | | - Guangbin Luo
- Department of Genetics and Genome Sciences, Case Comprehensive Cancer Center, and
| | - Hua Lou
- Department of Genetics and Genome Sciences, Case Comprehensive Cancer Center, and Center for RNA Molecular Biology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106
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