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Hirbe AC, Dehner CA, Dombi E, Eulo V, Gross AM, Sundby T, Lazar AJ, Widemann BC. Contemporary Approach to Neurofibromatosis Type 1-Associated Malignant Peripheral Nerve Sheath Tumors. Am Soc Clin Oncol Educ Book 2024; 44:e432242. [PMID: 38710002 DOI: 10.1200/edbk_432242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Most malignant peripheral nerve sheath tumors (MPNSTs) are clinically aggressive high-grade sarcomas, arising in individuals with neurofibromatosis type 1 (NF1) at a significantly elevated estimated lifetime frequency of 8%-13%. In the setting of NF1, MPNSTs arise from malignant transformation of benign plexiform neurofibroma and borderline atypical neurofibromas. Composed of neoplastic cells from the Schwannian lineage, these cancers recur in approximately 50% of individuals, and most patients die within five years of diagnosis, despite surgical resection, radiation, and chemotherapy. Treatment for metastatic disease is limited to cytotoxic chemotherapy and investigational clinical trials. In this article, we review the pathophysiology of this aggressive cancer and current approaches to surveillance and treatment.
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Affiliation(s)
- Angela C Hirbe
- Division of Oncology, Department of Medicine, Siteman Cancer Center, Barnes Jewish Hospital and Washington University School of Medicine, St Louis, MO
| | - Carina A Dehner
- Department of Anatomic Pathology and Laboratory Medicine, Indiana University, Indianapolis, IN
| | - Eva Dombi
- Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD
| | - Vanessa Eulo
- Division of Oncology, Department of Medicine, University of Alabama, Birmingham, AL
| | - Andrea M Gross
- Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD
| | - Taylor Sundby
- Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD
| | - Alexander J Lazar
- Departments of Pathology & Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX
| | - Brigitte C Widemann
- Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD
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2
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Timis T, Bergthorsson JT, Greiff V, Cenariu M, Cenariu D. Pathology and Molecular Biology of Melanoma. Curr Issues Mol Biol 2023; 45:5575-5597. [PMID: 37504268 PMCID: PMC10377842 DOI: 10.3390/cimb45070352] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 06/27/2023] [Accepted: 06/29/2023] [Indexed: 07/29/2023] Open
Abstract
Almost every death in young patients with an advanced skin tumor is caused by melanoma. Today, with the help of modern treatments, these patients survive longer or can even achieve a cure. Advanced stage melanoma is frequently related with poor prognosis and physicians still find this disease difficult to manage due to the absence of a lasting response to initial treatment regimens and the lack of randomized clinical trials in post immunotherapy/targeted molecular therapy settings. New therapeutic targets are emerging from preclinical data on the genetic profile of melanocytes and from the identification of molecular factors involved in the pathogenesis of malignant transformation. In the current paper, we present the diagnostic challenges, molecular biology and genetics of malignant melanoma, as well as the current therapeutic options for patients with this diagnosis.
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Affiliation(s)
- Tanase Timis
- Department of Oncology, Bistrita Emergency Hospital, 420094 Bistrita, Romania;
- Department of Hematology, Iuliu Hatieganu University of Medicine and Pharmacy, 400347 Cluj-Napoca, Romania
| | - Jon Thor Bergthorsson
- Department of Pharmacology and Toxicology, Medical Faculty, University of Iceland, Hofsvallagotu 53, 107 Reykjavík, Iceland;
| | - Victor Greiff
- Department of Immunology, University of Oslo, Oslo University Hospital, 0372 Oslo, Norway;
| | - Mihai Cenariu
- Department of Animal Reproduction, University of Agricultural Sciences and Veterinary Medicine, 3-5 Calea Manastur Street, 400372 Cluj-Napoca, Romania;
| | - Diana Cenariu
- Medfuture Research Center for Advanced Medicine, Iuliu Hatieganu University of Medicine and Pharmacy, 400337 Cluj-Napoca, Romania
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3
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Pan R, Dai J, Liang W, Wang H, Ye L, Ye S, Lin Z, Huang S, Xiong Y, Zhang L, Lu L, Wang O, Shen X, Liao W, Lu X. PDE4DIP contributes to colorectal cancer growth and chemoresistance through modulation of the NF1/RAS signaling axis. Cell Death Dis 2023; 14:373. [PMID: 37355626 PMCID: PMC10290635 DOI: 10.1038/s41419-023-05885-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 04/26/2023] [Accepted: 06/08/2023] [Indexed: 06/26/2023]
Abstract
Phosphodiesterase 4D interacting protein (PDE4DIP) is a centrosome/Golgi protein associated with cyclic nucleotide phosphodiesterases. PDE4DIP is commonly mutated in human cancers, and its alteration in mice leads to a predisposition to intestinal cancer. However, the biological function of PDE4DIP in human cancer remains obscure. Here, we report for the first time the oncogenic role of PDE4DIP in colorectal cancer (CRC) growth and adaptive MEK inhibitor (MEKi) resistance. We show that the expression of PDE4DIP is upregulated in CRC tissues and associated with the clinical characteristics and poor prognosis of CRC patients. Knockdown of PDE4DIP impairs the growth of KRAS-mutant CRC cells by inhibiting the core RAS signaling pathway. PDE4DIP plays an essential role in the full activation of oncogenic RAS/ERK signaling by suppressing the expression of the RAS GTPase-activating protein (RasGAP) neurofibromin (NF1). Mechanistically, PDE4DIP promotes the recruitment of PLCγ/PKCε to the Golgi apparatus, leading to constitutive activation of PKCε, which triggers the degradation of NF1. Upregulation of PDE4DIP results in adaptive MEKi resistance in KRAS-mutant CRC by reactivating the RAS/ERK pathway. Our work reveals a novel functional link between PDE4DIP and NF1/RAS signal transduction and suggests that targeting PDE4DIP is a promising therapeutic strategy for KRAS-mutant CRC.
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Affiliation(s)
- Rulu Pan
- School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, 325035, China
| | - Juji Dai
- Department of Colorectal and Anal Surgery, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000, China
| | - Weicheng Liang
- School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, 325035, China
| | - Hongxiao Wang
- School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, 325035, China
| | - Lin Ye
- School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, 325035, China
| | - Siqi Ye
- School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, 325035, China
| | - Ziqi Lin
- School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, 325035, China
| | - Shishun Huang
- School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, 325035, China
| | - Yan Xiong
- School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, 325035, China
| | - Li Zhang
- School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, 325035, China
| | - Liting Lu
- School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, 325035, China
| | - Ouchen Wang
- Department of Breast Surgery, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000, China
| | - Xian Shen
- Department of General Surgery, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000, China
| | - Wanqin Liao
- School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, 325035, China.
| | - Xincheng Lu
- School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, 325035, China.
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4
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Wang W, Li X, Qin X, Miao Y, Zhang Y, Li S, Yao R, Yang Y, Yu L, Zhu H, Song L, Mao S, Wang X, Chen J, Feng H, Li Y. Germline Neurofibromin 1 mutation enhances the anti-tumour immune response and decreases juvenile myelomonocytic leukaemia tumourigenicity. Br J Haematol 2023. [PMID: 37144690 DOI: 10.1111/bjh.18851] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 04/10/2023] [Accepted: 04/25/2023] [Indexed: 05/06/2023]
Abstract
Juvenile myelomonocytic leukaemia (JMML) is an aggressive paediatric leukaemia characterized by mutations in five canonical RAS pathway genes, including the NF1 gene. JMML is driven by germline NF1 gene mutations, with additional somatic aberrations resulting in the NF1 biallelic inactivation, leading to disease progression. Germline mutations in the NF1 gene alone primarily cause benign neurofibromatosis type 1 (NF1) tumours rather than malignant JMML, yet the underlying mechanism remains unclear. Here, we demonstrate that with reduced NF1 gene dose, immune cells are promoted in anti-tumour immune response. Comparing the biological properties of JMML and NF1 patients, we found that not only JMML but also NF1 patients driven by NF1 mutations could increase monocytes generation. But monocytes cannot further malignant development in NF1 patients. Utilizing haematopoietic and macrophage differentiation from iPSCs, we revealed that NF1 mutations or knockout (KO) recapitulated the classical haematopoietic pathological features of JMML with reduced NF1 gene dose. NF1 mutations or KO promoted the proliferation and immune function of NK cells and iMacs derived from iPSCs. Moreover, NF1-mutated iNKs had a high capacity to kill NF1-KO iMacs. NF1-mutated or KO iNKs administration delayed leukaemia progression in a xenograft animal model. Our findings demonstrate that germline NF1 mutations alone cannot directly drive JMML development and suggest a potential cell immunotherapy for JMML patients.
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Affiliation(s)
- Wanqiao Wang
- Pediatric Translational Medicine Institute, Department of Hematology & Oncology, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Key Laboratory of Pediatric Hematology & Oncology of China Ministry of Health, Shanghai, China
| | - Xin Li
- Department of Endocrinology and Metabolism, Shanghai Children's Medical Center, Shanghai, China
| | - Xia Qin
- Department of Hematology & Oncology, Shanghai Children's Medical Center, Shanghai, China
| | - Yan Miao
- Department of Hematology & Oncology, Shanghai Children's Medical Center, Shanghai, China
| | - Yingwen Zhang
- State Key Laboratory of Oncogenes and Related Genes, Renji-Med X Clinical Stem Cell Research Center, Ren Ji Hospital, Shanghai Cancer Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Shanshan Li
- Pediatric Translational Medicine Institute, Department of Hematology & Oncology, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Key Laboratory of Pediatric Hematology & Oncology of China Ministry of Health, Shanghai, China
| | - Ruen Yao
- Department of Medical Genetics, Shanghai Children's Medical Center, Shanghai, China
| | - Yi Yang
- Pediatric Translational Medicine Institute, Department of Hematology & Oncology, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Key Laboratory of Pediatric Hematology & Oncology of China Ministry of Health, Shanghai, China
| | - Lisha Yu
- Department of Hematology & Oncology, Shanghai Children's Medical Center, Shanghai, China
| | - Hua Zhu
- Department of Hematology & Oncology, Shanghai Children's Medical Center, Shanghai, China
| | - Lili Song
- Department of Hematology & Oncology, Shanghai Children's Medical Center, Shanghai, China
| | - Shengqiao Mao
- Department of Hematology & Oncology, Shanghai Children's Medical Center, Shanghai, China
| | - Xiumin Wang
- Department of Endocrinology and Metabolism, Shanghai Children's Medical Center, Shanghai, China
| | - Jing Chen
- Department of Hematology & Oncology, Shanghai Children's Medical Center, Shanghai, China
| | - Haizhong Feng
- State Key Laboratory of Oncogenes and Related Genes, Renji-Med X Clinical Stem Cell Research Center, Ren Ji Hospital, Shanghai Cancer Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yanxin Li
- Pediatric Translational Medicine Institute, Department of Hematology & Oncology, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Key Laboratory of Pediatric Hematology & Oncology of China Ministry of Health, Shanghai, China
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5
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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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6
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Role of nerves in neurofibromatosis type 1-related nervous system tumors. Cell Oncol (Dordr) 2022; 45:1137-1153. [PMID: 36327093 DOI: 10.1007/s13402-022-00723-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/22/2022] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND Neurofibromatosis type 1 (NF1) is an autosomal dominant genetic disorder that affects nearly 1 in 3000 infants. Neurofibromin inactivation and NF1 gene mutations are involved in various aspects of neuronal function regulation, including neuronal development induction, electrophysiological activity elevation, growth factor expression, and neurotransmitter release. NF1 patients often exhibit a predisposition to tumor development, especially in the nervous system, resulting in the frequent occurrence of peripheral nerve sheath tumors and gliomas. Recent evidence suggests that nerves play a role in the development of multiple tumor types, prompting researchers to investigate the nerve as a vital component in and regulator of the initiation and progression of NF1-related nervous system tumors. CONCLUSION In this review, we summarize existing evidence about the specific effects of NF1 mutation on neurons and emerging research on the role of nerves in neurological tumor development, promising a new set of selective and targeted therapies for NF1-related tumors.
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7
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Cai X, Xiang S, He W, Tang M, Zhang S, Chen D, Zhang X, Liu C, Li G, Xing J, Li Y, Chen X, Nie Y. Deubiquitinase Ubp3 regulates ribophagy and deubiquitinates Smo1 for appressorium-mediated infection by Magnaporthe oryzae. MOLECULAR PLANT PATHOLOGY 2022; 23:832-844. [PMID: 35220670 PMCID: PMC9104258 DOI: 10.1111/mpp.13196] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 02/09/2022] [Accepted: 02/09/2022] [Indexed: 06/14/2023]
Abstract
The Ubp family of deubiquitinating enzymes has been found to play important roles in plant-pathogenic fungi, but their regulatory mechanisms are still largely unknown. In this study, we revealed the regulatory mechanism of the deubiquitinating enzyme Ubp3 during the infection process of Magnaporthe oryzae. AUBP3 deletion mutant was severely defective in appressorium turgor accumulation, leading to the impairment of appressorial penetration. During appressorium formation, the mutant was also defective in glycogen and lipid metabolism. Interestingly, we found that nitrogen starvation and rapamycin treatment induced the ribophagy process in M. oryzae, which is closely dependent on Ubp3. In the ∆ubp3 mutant, the ribosome proteins and rRNAs were not well degraded on nitrogen starvation and rapamycin treatment. We also found that Ubp3 interacted with the GTPase-activating protein Smo1 and regulated its de-ubiquitination. Ubp3-dependent de-ubiquitination of Smo1 may be required for Smo1 to coordinate Ras signalling. Taken together, our results showed at least two roles of Ubp3 in M. oryzae: it regulates the ribophagy process and it regulates de-ubiquitination of GTPase-activating protein Smo1 for appressorium-mediated infection.
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Affiliation(s)
- Xuan Cai
- Laboratory of Physiological Plant PathologySouth China Agricultural UniversityGuangzhouChina
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei ProvinceCollege of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanChina
| | - Shikun Xiang
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei ProvinceCollege of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanChina
| | - Wenhui He
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei ProvinceCollege of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanChina
| | - Mengxi Tang
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei ProvinceCollege of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanChina
| | - Shimei Zhang
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei ProvinceCollege of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanChina
| | - Deng Chen
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei ProvinceCollege of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanChina
| | - Xinrong Zhang
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei ProvinceCollege of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanChina
| | - Caiyun Liu
- Laboratory of Physiological Plant PathologySouth China Agricultural UniversityGuangzhouChina
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei ProvinceCollege of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanChina
| | - Guotian Li
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei ProvinceCollege of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanChina
| | - Junjie Xing
- State Key Laboratory of Hybrid RiceHunan Hybrid Rice Research CenterChangshaChina
| | - Yunfeng Li
- Laboratory of Physiological Plant PathologySouth China Agricultural UniversityGuangzhouChina
| | - Xiao‐Lin Chen
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei ProvinceCollege of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanChina
| | - Yanfang Nie
- Laboratory of Physiological Plant PathologySouth China Agricultural UniversityGuangzhouChina
- College of Materials and EnergySouth China Agricultural UniversityGuangzhouChina
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8
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Genomic and Epigenomic Landscape of Juvenile Myelomonocytic Leukemia. Cancers (Basel) 2022; 14:cancers14051335. [PMID: 35267643 PMCID: PMC8909150 DOI: 10.3390/cancers14051335] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 02/25/2022] [Accepted: 03/02/2022] [Indexed: 02/04/2023] Open
Abstract
Simple Summary Juvenile myelomonocytic leukemia (JMML) is a rare pediatric myelodysplastic/myeloproliferative neoplasm characterized by the constitutive activation of the RAS pathway. In spite of the recent progresses in the molecular characterization of JMML, this disease is still a clinical challenge due to its heterogeneity, difficult diagnosis, poor prognosis, and the lack of curative treatment options other than hematopoietic stem cell transplantation (HSCT). In this review, we will provide a detailed overview of the genetic and epigenetic alterations occurring in JMML, and discuss their clinical relevance in terms of disease prognosis and risk of relapse after HSCT. We will also present the most recent advances on novel preclinical and clinical therapeutic approaches directed against JMML molecular targets. Finally, we will outline future research perspectives to further explore the oncogenic mechanism driving JMML leukemogenesis and progression, with special attention to the application of single-cell next-generation sequencing technologies. Abstract Juvenile myelomonocytic leukemia (JMML) is a rare myelodysplastic/myeloproliferative neoplasm of early childhood. Most of JMML patients experience an aggressive clinical course of the disease and require hematopoietic stem cell transplantation, which is currently the only curative treatment. JMML is characterized by RAS signaling hyperactivation, which is mainly driven by mutations in one of five genes of the RAS pathway, including PTPN11, KRAS, NRAS, NF1, and CBL. These driving mutations define different disease subtypes with specific clinico-biological features. Secondary mutations affecting other genes inside and outside the RAS pathway contribute to JMML pathogenesis and are associated with a poorer prognosis. In addition to these genetic alterations, JMML commonly presents aberrant epigenetic profiles that strongly correlate with the clinical outcome of the patients. This observation led to the recent publication of an international JMML stratification consensus, which defines three JMML clinical groups based on DNA methylation status. Although the characterization of the genomic and epigenomic landscapes in JMML has significantly contributed to better understand the molecular mechanisms driving the disease, our knowledge on JMML origin, cell identity, and intratumor and interpatient heterogeneity is still scarce. The application of new single-cell sequencing technologies will be critical to address these questions in the future.
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9
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Zhao Z, Xu Q, Wei R, Huang L, Wang W, Wei G, Ni T. Comprehensive characterization of somatic variants associated with intronic polyadenylation in human cancers. Nucleic Acids Res 2021; 49:10369-10381. [PMID: 34508351 PMCID: PMC8501991 DOI: 10.1093/nar/gkab772] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 08/16/2021] [Accepted: 08/26/2021] [Indexed: 11/29/2022] Open
Abstract
Somatic single nucleotide variants (SNVs) in cancer genome affect gene expression through various mechanisms depending on their genomic location. While somatic SNVs near canonical splice sites have been reported to cause abnormal splicing of cancer-related genes, whether these SNVs can affect gene expression through other mechanisms remains an open question. Here, we analyzed RNA sequencing and exome data from 4,998 cancer patients covering ten cancer types and identified 152 somatic SNVs near splice sites that were associated with abnormal intronic polyadenylation (IPA). IPA-associated somatic variants favored the localization near the donor splice sites compared to the acceptor splice sites. A proportion of SNV-associated IPA events overlapped with premature cleavage and polyadenylation events triggered by U1 small nuclear ribonucleoproteins (snRNP) inhibition. GC content, intron length and polyadenylation signal were three genomic features that differentiated between SNV-associated IPA and intron retention. Notably, IPA-associated SNVs were enriched in tumor suppressor genes (TSGs), including the well-known TSGs such as PTEN and CDH1 with recurrent SNV-associated IPA events. Minigene assay confirmed that SNVs from PTEN, CDH1, VEGFA, GRHL2, CUL3 and WWC2 could lead to IPA. This work reveals that IPA acts as a novel mechanism explaining the functional consequence of somatic SNVs in human cancer.
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Affiliation(s)
- Zhaozhao Zhao
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Human Phenome Institute, School of Life Sciences and Huashan Hospital, Fudan University, Shanghai 200438, P.R. China
| | - Qiushi Xu
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Human Phenome Institute, School of Life Sciences and Huashan Hospital, Fudan University, Shanghai 200438, P.R. China
| | - Ran Wei
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Human Phenome Institute, School of Life Sciences and Huashan Hospital, Fudan University, Shanghai 200438, P.R. China.,Department of Pathology, Fudan University Shanghai Cancer Center, Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, P.R. China
| | - Leihuan Huang
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Human Phenome Institute, School of Life Sciences and Huashan Hospital, Fudan University, Shanghai 200438, P.R. China
| | - Weixu Wang
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Human Phenome Institute, School of Life Sciences and Huashan Hospital, Fudan University, Shanghai 200438, P.R. China
| | - Gang Wei
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Human Phenome Institute, School of Life Sciences and Huashan Hospital, Fudan University, Shanghai 200438, P.R. China.,MOE Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai 200438, P.R. China
| | - Ting Ni
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Human Phenome Institute, School of Life Sciences and Huashan Hospital, Fudan University, Shanghai 200438, P.R. China.,Shanghai Engineering Research Center of Industrial Microorganisms, School of Life Sciences, Fudan University, Shanghai 200438, P.R. China
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10
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Mlakar V, Morel E, Mlakar SJ, Ansari M, Gumy-Pause F. A review of the biological and clinical implications of RAS-MAPK pathway alterations in neuroblastoma. JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH : CR 2021; 40:189. [PMID: 34103089 PMCID: PMC8188681 DOI: 10.1186/s13046-021-01967-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 04/27/2021] [Indexed: 02/07/2023]
Abstract
Neuroblastoma is the most common extra-cranial solid tumor in children, representing approximately 8% of all malignant childhood tumors and 15% of pediatric cancer-related deaths. Recent sequencing and transcriptomics studies have demonstrated the RAS-MAPK pathway’s contribution to the development and progression of neuroblastoma. This review compiles up-to-date evidence of this pathway’s involvement in neuroblastoma. We discuss the RAS-MAPK pathway’s general functioning, the clinical implications of its deregulation in neuroblastoma, and current promising therapeutics targeting proteins involved in signaling.
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Affiliation(s)
- Vid Mlakar
- CANSEARCH Research Platform for Pediatric Oncology and Hematology, Department of Pediatrics, Gynecology and Obstetrics, Faculty of Medicine, University of Geneva, Avenue de la Roseraie 64, 1205, Geneva, Switzerland
| | - Edouard Morel
- CANSEARCH Research Platform for Pediatric Oncology and Hematology, Department of Pediatrics, Gynecology and Obstetrics, Faculty of Medicine, University of Geneva, Avenue de la Roseraie 64, 1205, Geneva, Switzerland
| | - Simona Jurkovic Mlakar
- CANSEARCH Research Platform for Pediatric Oncology and Hematology, Department of Pediatrics, Gynecology and Obstetrics, Faculty of Medicine, University of Geneva, Avenue de la Roseraie 64, 1205, Geneva, Switzerland
| | - Marc Ansari
- CANSEARCH Research Platform for Pediatric Oncology and Hematology, Department of Pediatrics, Gynecology and Obstetrics, Faculty of Medicine, University of Geneva, Avenue de la Roseraie 64, 1205, Geneva, Switzerland.,Division of Pediatric Oncology and Hematology, Department of Women, Child and Adolescent, University Hospital of Geneva, Rue Willy-Donzé 6, 1205, Geneva, Switzerland
| | - Fabienne Gumy-Pause
- CANSEARCH Research Platform for Pediatric Oncology and Hematology, Department of Pediatrics, Gynecology and Obstetrics, Faculty of Medicine, University of Geneva, Avenue de la Roseraie 64, 1205, Geneva, Switzerland. .,Division of Pediatric Oncology and Hematology, Department of Women, Child and Adolescent, University Hospital of Geneva, Rue Willy-Donzé 6, 1205, Geneva, Switzerland.
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11
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Longo JF, Brosius SN, Znoyko I, Alers VA, Jenkins DP, Wilson RC, Carroll AJ, Wolff DJ, Roth KA, Carroll SL. Establishment and genomic characterization of a sporadic malignant peripheral nerve sheath tumor cell line. Sci Rep 2021; 11:5690. [PMID: 33707600 PMCID: PMC7952412 DOI: 10.1038/s41598-021-85055-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 02/17/2021] [Indexed: 12/19/2022] Open
Abstract
Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive Schwann cell-derived neoplasms that occur sporadically or in patients with neurofibromatosis type 1 (NF1). Preclinical research on sporadic MPNSTs has been limited as few cell lines exist. We generated and characterized a new sporadic MPNST cell line, 2XSB, which shares the molecular and genomic features of the parent tumor. These cells have a highly complex karyotype with extensive chromothripsis. 2XSB cells show robust invasive 3-dimensional and clonogenic culture capability and form solid tumors when xenografted into immunodeficient mice. High-density single nucleotide polymorphism array and whole exome sequencing analyses indicate that, unlike NF1-associated MPNSTs, 2XSB cells have intact, functional NF1 alleles with no evidence of mutations in genes encoding components of Polycomb Repressor Complex 2. However, mutations in other genes implicated in MPNST pathogenesis were identified in 2XSB cells including homozygous deletion of CDKN2A and mutations in TP53 and PTEN. We also identified mutations in genes not previously associated with MPNSTs but associated with the pathogenesis of other human cancers. These include DNMT1, NUMA1, NTRK1, PDE11A, CSMD3, LRP5 and ACTL9. This sporadic MPNST-derived cell line provides a useful tool for investigating the biology and potential treatment regimens for sporadic MPNSTs.
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Affiliation(s)
- Jody Fromm Longo
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, 171 Ashley Avenue, MSC 908, Charleston, SC, 29425-9080, USA
| | - Stephanie N Brosius
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, 35294-0017, USA.,Medical Scientist Training Program, University of Alabama at Birmingham, Birmingham, AL, 35294-0017, USA.,Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Iya Znoyko
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, 171 Ashley Avenue, MSC 908, Charleston, SC, 29425-9080, USA
| | - Victoria A Alers
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, 171 Ashley Avenue, MSC 908, Charleston, SC, 29425-9080, USA
| | - Dorea P Jenkins
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, 171 Ashley Avenue, MSC 908, Charleston, SC, 29425-9080, USA
| | - Robert C Wilson
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, 171 Ashley Avenue, MSC 908, Charleston, SC, 29425-9080, USA.,Center for Genomic Medicine, Medical University of South Carolina, Charleston, SC, 29425-9080, USA
| | - Andrew J Carroll
- Department of Genetics, University of Alabama at Birmingham, Birmingham, AL, 35294-0017, USA
| | - Daynna J Wolff
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, 171 Ashley Avenue, MSC 908, Charleston, SC, 29425-9080, USA
| | - Kevin A Roth
- Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, 10032, USA
| | - Steven L Carroll
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, 171 Ashley Avenue, MSC 908, Charleston, SC, 29425-9080, USA. .,Center for Genomic Medicine, Medical University of South Carolina, Charleston, SC, 29425-9080, USA. .,Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, 35294-0017, USA.
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12
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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: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 10/21/2020] [Accepted: 10/26/2020] [Indexed: 12/13/2022] Open
Abstract
Neurofibromin is a large and multifunctional protein encoded by the tumor suppressor gene NF1, mutations of which cause the tumor predisposition syndrome neurofibromatosis type 1 (NF1). Over the last three decades, studies of neurofibromin structure, interacting partners, and functions have shown that it is involved in several cell signaling pathways, including the Ras/MAPK, Akt/mTOR, ROCK/LIMK/cofilin, and cAMP/PKA pathways, and regulates many fundamental cellular processes, such as proliferation and migration, cytoskeletal dynamics, neurite outgrowth, dendritic-spine density, and dopamine levels. The crystallographic structure has been resolved for two of its functional domains, GRD (GAP-related (GTPase-activating protein) domain) and SecPH, and its post-translational modifications studied, showing it to be localized to several cell compartments. These findings have been of particular interest in the identification of many therapeutic targets and in the proposal of various therapeutic strategies to treat the symptoms of NF1. In this review, we provide an overview of the literature on neurofibromin structure, function, interactions, and regulation and highlight the relationships between them.
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13
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Bellazzo A, Collavin L. Cutting the Brakes on Ras-Cytoplasmic GAPs as Targets of Inactivation in Cancer. Cancers (Basel) 2020; 12:cancers12103066. [PMID: 33096593 PMCID: PMC7588890 DOI: 10.3390/cancers12103066] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 10/11/2020] [Accepted: 10/15/2020] [Indexed: 12/16/2022] Open
Abstract
Simple Summary GTPase-Activating Proteins (RasGAPs) are a group of structurally related proteins with a fundamental role in controlling the activity of Ras in normal and cancer cells. In particular, loss of function of RasGAPs may contribute to aberrant Ras activation in cancer. Here we review the multiple molecular mechanisms and factors that are involved in downregulating RasGAPs expression and functions in cancer. Additionally, we discuss how extracellular stimuli from the tumor microenvironment can control RasGAPs expression and activity in cancer cells and stromal cells, indirectly affecting Ras activation, with implications for cancer development and progression. Abstract The Ras pathway is frequently deregulated in cancer, actively contributing to tumor development and progression. Oncogenic activation of the Ras pathway is commonly due to point mutation of one of the three Ras genes, which occurs in almost one third of human cancers. In the absence of Ras mutation, the pathway is frequently activated by alternative means, including the loss of function of Ras inhibitors. Among Ras inhibitors, the GTPase-Activating Proteins (RasGAPs) are major players, given their ability to modulate multiple cancer-related pathways. In fact, most RasGAPs also have a multi-domain structure that allows them to act as scaffold or adaptor proteins, affecting additional oncogenic cascades. In cancer cells, various mechanisms can cause the loss of function of Ras inhibitors; here, we review the available evidence of RasGAP inactivation in cancer, with a specific focus on the mechanisms. We also consider extracellular inputs that can affect RasGAP levels and functions, implicating that specific conditions in the tumor microenvironment can foster or counteract Ras signaling through negative or positive modulation of RasGAPs. A better understanding of these conditions might have relevant clinical repercussions, since treatments to restore or enhance the function of RasGAPs in cancer would help circumvent the intrinsic difficulty of directly targeting the Ras protein.
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14
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Schreck KC, Allen AN, Wang J, Pratilas CA. Combination MEK and mTOR inhibitor therapy is active in models of glioblastoma. Neurooncol Adv 2020; 2:vdaa138. [PMID: 33235998 PMCID: PMC7668446 DOI: 10.1093/noajnl/vdaa138] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Background RAS effector signaling pathways such as PI3K/mTOR and ERK are frequently dysregulated in glioblastoma. While small molecule targeted therapies against these pathways have appeared promising in preclinical studies, they have been disappointing in clinical trials due to toxicity and de novo and adaptive resistance. To identify predictors of glioblastoma sensitivity to dual pathway inhibition with mTORC1/2 and MEK inhibitors, we tested these agents, alone and in combination, in a cohort of genomically characterized glioblastoma cell lines. Methods Seven genomically characterized, patient-derived glioblastoma neurosphere cell lines were evaluated for their sensitivity to the dual mTORC1/2 kinase inhibitor sapanisertib (MLN0128, TAK-228) alone or in combination with the MEK1/2 inhibitor trametinib (GSK1120212), using assessment of proliferation and evaluation of the downstream signaling consequences of these inhibitors. Results Sapanisertib inhibited cell growth in neurosphere lines, but induced apoptosis only in a subset of lines, and did not completely inhibit downstream mTOR signaling via ribosomal protein S6 (RPS6). Growth sensitivity to MEK inhibitor monotherapy was observed in a subset of lines defined by loss of NF1, was predicted by an ERK-dependent expression signature, and was associated with effective phospho-RPS6 inhibition. In these lines, combined MEK/mTOR treatment further inhibited growth and induced apoptosis. Combined MEK and mTOR inhibition also led to modest antiproliferative effects in lines with intact NF1 and insensitivity to MEK inhibitor monotherapy. Conclusions These data demonstrate that combined MEK/mTOR inhibition is synergistic in glioblastoma cell lines and may be more potent in NF1-deficient glioblastoma.
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Affiliation(s)
- Karisa C Schreck
- Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, Maryland, USA.,Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Amy N Allen
- Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, Maryland, USA.,Division of Pediatric Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Jiawan Wang
- Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, Maryland, USA.,Division of Pediatric Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Christine A Pratilas
- Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, Maryland, USA.,Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,Division of Pediatric Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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15
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Transcriptome-wide Sequencing Reveals Molecules and Pathways Involved in Neurofibromatosis Type I Combined With Spinal Deformities. Spine (Phila Pa 1976) 2020; 45:E489-E498. [PMID: 31770328 DOI: 10.1097/brs.0000000000003338] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
UNLABELLED MINI: We identified differentially expressed genes (DEGs) that may be involved in the development of neurofibromatosis type I by whole-transcriptional sequencing. Seven hundred eighty DEGs were identified which include protein coding genes, miRNAs, and lncRNAs. The enrichment analysis may reveal pathways that these DEGs involved. A total of 383 protein-pairs for DEGs may unfold the possible mechanism how the disease is developed. STUDY DESIGN This is a clinical basic study on neurofibromatosis type I (NF-1) with spinal deformity. OBJECTIVE The current research focuses on screening key molecules affecting NF-1 with spinal deformity by transcriptome sequencing and discovering its underlying molecular biological mechanisms. SUMMARY OF BACKGROUND DATA NF-1 is a complex multisystem human disorder, which is often found in spinal deformities patients. The success rate of orthopedic surgery for neurofibromatosis type I combined with spinal deformities patients was low because of the lack of molecular pathology. METHODS In our study, the transcriptome-wide sequencing was preformed to identify the differentially expressed genes (DEGs) involved in this disease. RESULTS Seven hundred eighty DEGs were identified which include protein coding genes, miRNAs, and lncRNAs. The DO, GO, KEGG and Reactome enrichment analysis may reveal pathways that these DEGs involved. And the 383 protein-pairs for DEGs that are involved in NF-1 combined with spinal deformities may unfold the possible mechanism how this disease is developed. CONCLUSION The differentially expressed miRNAs and lncRNAs may contribute the ceRNA network. We focused on three key DEGs: FGFR2, MAP3K1 and STAT4. FGFR2 and MAP3K1 are members of the RAS/RAF/MEK/ERK-signaling pathway, and STAT4 were involved in the JAK/STAT pathway. The expression changes were verified by other researches and the functional cross-talk between the Ras/MAPK and JAK/STAT pathways may contribute in the disease development. This study took insight of the molecular mechanism of this disease. More detailed interactions between these factors are needed to be further explored. These key DEGs and involved pathways may provide clues in the clinical process for patients with NF-1, especially in prognosis prediction. LEVEL OF EVIDENCE N/A.
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16
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Affinity Purification of NF1 Protein-Protein Interactors Identifies Keratins and Neurofibromin Itself as Binding Partners. Genes (Basel) 2019; 10:genes10090650. [PMID: 31466283 PMCID: PMC6770187 DOI: 10.3390/genes10090650] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 08/09/2019] [Accepted: 08/19/2019] [Indexed: 12/23/2022] Open
Abstract
Neurofibromatosis Type 1 (NF1) is caused by pathogenic variants in the NF1 gene encoding neurofibromin. Definition of NF1 protein–protein interactions (PPIs) has been difficult and lacks replication, making it challenging to define binding partners that modulate its function. We created a novel tandem affinity purification (TAP) tag cloned in frame to the 3’ end of the full-length murine Nf1 cDNA (mNf1). We show that this cDNA is functional and expresses neurofibromin, His-Tag, and can correct p-ERK/ERK ratios in NF1 null HEK293 cells. We used this affinity tag to purify binding partners with Strep-Tactin®XT beads and subsequently, identified them via mass spectrometry (MS). We found the tagged mNf1 can affinity purify human neurofibromin and vice versa, indicating that neurofibromin oligomerizes. We identify 21 additional proteins with high confidence of interaction with neurofibromin. After Metacore network analysis of these 21 proteins, eight appear within the same network, primarily keratins regulated by estrogen receptors. Previously, we have shown that neurofibromin levels negatively regulate keratin expression. Here, we show through pharmacological inhibition that this is independent of Ras signaling, as the inhibitors, selumetinib and rapamycin, do not alter keratin expression. Further characterization of neurofibromin oligomerization and binding partners could aid in discovering new neurofibromin functions outside of Ras regulation, leading to novel drug targets.
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17
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Scheffzek K, Shivalingaiah G. Ras-Specific GTPase-Activating Proteins-Structures, Mechanisms, and Interactions. Cold Spring Harb Perspect Med 2019; 9:cshperspect.a031500. [PMID: 30104198 DOI: 10.1101/cshperspect.a031500] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Ras-specific GTPase-activating proteins (RasGAPs) down-regulate the biological activity of Ras proteins by accelerating their intrinsic rate of GTP hydrolysis, basically by a transition state stabilizing mechanism. Oncogenic Ras is commonly not sensitive to RasGAPs caused by interference of mutants with the electronic or steric requirements of the transition state, resulting in up-regulation of activated Ras in respective cells. RasGAPs are modular proteins containing a helical catalytic RasGAP module surrounded by smaller domains that are frequently involved in the subcellular localization or contributing to regulatory features of their host proteins. In this review, we summarize current knowledge about RasGAP structure, mechanism, regulation, and dual-substrate specificity and discuss in some detail neurofibromin, one of the most important negative Ras regulators in cellular growth control and neuronal function.
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Affiliation(s)
- Klaus Scheffzek
- Division of Biological Chemistry (Biocenter), Medical University of Innsbruck, A-6020 Innsbruck, Austria
| | - Giridhar Shivalingaiah
- Division of Biological Chemistry (Biocenter), Medical University of Innsbruck, A-6020 Innsbruck, Austria
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18
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Post JB, Hami N, Mertens AEE, Elfrink S, Bos JL, Snippert HJG. CRISPR-induced RASGAP deficiencies in colorectal cancer organoids reveal that only loss of NF1 promotes resistance to EGFR inhibition. Oncotarget 2019; 10:1440-1457. [PMID: 30858928 PMCID: PMC6402720 DOI: 10.18632/oncotarget.26677] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 02/01/2019] [Indexed: 12/16/2022] Open
Abstract
Anti-EGFR therapy is used to treat metastatic colorectal cancer (CRC) patients, for which initial response rates of 10-20% have been achieved. Although the presence of HER2 amplifications and oncogenic mutations in KRAS, NRAS, and BRAF are associated with EGFR-targeted therapy resistance, for a large population of CRC patients the underlying mechanism of RAS-MEK-ERK hyperactivation is not clear. Loss-of-function mutations in RASGAPs are often speculated in literature to promote CRC growth as being negative regulators of RAS, but direct experimental evidence is lacking. We generated a CRISPR-mediated knock out panel of all RASGAPs in patient-derived CRC organoids and found that only loss of NF1, but no other RASGAPs e.g. RASA1, results in enhanced RAS-ERK signal amplification and improved tolerance towards limited EGF stimulation. Our data suggests that NF1-deficient CRCs are likely not responsive to anti-EGFR monotherapy and can potentially function as a biomarker for CRC progression.
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Affiliation(s)
- Jasmin B Post
- Center for Molecular Medicine, Section Molecular Cancer Research, University Medical Center Utrecht, Utrecht, The Netherlands.,Oncode Netherlands, Institute Netherlands, Office Jaarbeurs Innovation Mile, Utrecht, The Netherlands
| | - Nizar Hami
- Center for Molecular Medicine, Section Molecular Cancer Research, University Medical Center Utrecht, Utrecht, The Netherlands.,Oncode Netherlands, Institute Netherlands, Office Jaarbeurs Innovation Mile, Utrecht, The Netherlands
| | - Alexander E E Mertens
- Center for Molecular Medicine, Section Molecular Cancer Research, University Medical Center Utrecht, Utrecht, The Netherlands.,Oncode Netherlands, Institute Netherlands, Office Jaarbeurs Innovation Mile, Utrecht, The Netherlands
| | - Suraya Elfrink
- Center for Molecular Medicine, Section Molecular Cancer Research, University Medical Center Utrecht, Utrecht, The Netherlands.,Oncode Netherlands, Institute Netherlands, Office Jaarbeurs Innovation Mile, Utrecht, The Netherlands
| | - Johannes L Bos
- Center for Molecular Medicine, Section Molecular Cancer Research, University Medical Center Utrecht, Utrecht, The Netherlands.,Oncode Netherlands, Institute Netherlands, Office Jaarbeurs Innovation Mile, Utrecht, The Netherlands
| | - Hugo J G Snippert
- Center for Molecular Medicine, Section Molecular Cancer Research, University Medical Center Utrecht, Utrecht, The Netherlands.,Oncode Netherlands, Institute Netherlands, Office Jaarbeurs Innovation Mile, Utrecht, The Netherlands
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19
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Green YS, Sargis T, Reichert EC, Rudasi E, Fuja D, Jonasch E, Koh MY. Hypoxia-Associated Factor (HAF) Mediates Neurofibromin Ubiquitination and Degradation Leading to Ras-ERK Pathway Activation in Hypoxia. Mol Cancer Res 2019; 17:1220-1232. [PMID: 30705246 DOI: 10.1158/1541-7786.mcr-18-1080] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Revised: 01/07/2019] [Accepted: 01/24/2019] [Indexed: 01/05/2023]
Abstract
Low oxygen or hypoxia is a feature of all solid tumors and has been associated with aggressive disease. Here, we describe a novel mechanism for the hypoxia-dependent degradation of the Ras-GTPase-activating protein neurofibromin, by hypoxia-associated factor (HAF). We have previously characterized HAF as an oxygen-independent ubiquitin ligase for HIF-1α. Here, we show that HAF promotes neurofibromin ubiquitination and degradation independently of oxygen and pVHL, resulting in Ras-ERK pathway activation. Hypoxia enhanced HAF:neurofibromin binding independently of HAF-SUMOylation, whereas HAF knockdown increased neurofibromin levels primarily in hypoxia, supporting the role of HAF as a hypoxia-specific neurofibromin regulator. HAF overexpression increased p-ERK levels and promoted resistance of clear cell kidney cancer (ccRCC) cells to sorafenib and sunitinib in both normoxia and hypoxia. However, a greater-fold increase in sorafenib/sunitinib resistance was observed during hypoxia, particularly in pVHL-deficient cells. Intriguingly, HAF-mediated resistance was HIF-2α-dependent in normoxia, but HIF-2α-independent in hypoxia indicating two potential mechanisms of HAF-mediated resistance: a HIF-2α-dependent pathway dominant in normoxia, and the direct activation of the Ras-ERK pathway through neurofibromin degradation dominant in hypoxia. Patients with ccRCC with high HAF transcript or protein levels showed significantly decreased overall survival compared with those with low HAF. Thus, we establish a novel, nonmutational pathway of neurofibromin inactivation through hypoxia-induced HAF-mediated degradation, leading to Ras-ERK activation and poor prognosis in ccRCC. IMPLICATIONS: We describe a novel mechanism of neurofibromin degradation induced by hypoxia that leads to activation of the prooncogenic Ras-ERK pathway and resistance to therapy.
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Affiliation(s)
- Yangsook Song Green
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah
| | - Timothy Sargis
- Department of Physiology and Biophysics, College of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | | | - Eleanor Rudasi
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah
| | - Daniel Fuja
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah
| | - Eric Jonasch
- Department of Genitourinary Medical Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Mei Yee Koh
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah.
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20
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Molosh AI, Shekhar A. Neurofibromatosis type 1 as a model system to study molecular mechanisms of autism spectrum disorder symptoms. PROGRESS IN BRAIN RESEARCH 2018; 241:37-62. [PMID: 30447756 DOI: 10.1016/bs.pbr.2018.09.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Neurofibromatosis type 1 (NF1) is monogenic neurodevelopmental disorder caused by mutation of NF1 gene, which leads to increased susceptibility to various tumors formations. Additionally, majority of patients with NF1 are experience high incidence of cognitive deficits. Particularly, we review the growing number of reports demonstrated a higher incidence of autism spectrum disorder (ASD) in individuals with NF1. In this review we also discuss face validity of preclinical Nf1 mouse models. Then we describe discoveries from these animal models that have uncovered the deficiencies in the regulation of Ras and other intracellular pathways as critical mechanisms underlying the Nf1 cognitive problems. We also summarize and interpret recent preclinical and clinical studies that point toward potential pharmacological therapies for NF1 patients.
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Affiliation(s)
- Andrei I Molosh
- Department of Psychiatry, Institute of Psychiatric Research, IU School of Medicine, Indianapolis, IN, United States; Stark Neurosciences Research Institute, IU School of Medicine, Indianapolis, IN, United States.
| | - Anantha Shekhar
- Department of Psychiatry, Institute of Psychiatric Research, IU School of Medicine, Indianapolis, IN, United States; Stark Neurosciences Research Institute, IU School of Medicine, Indianapolis, IN, United States; Department of Pharmacology & Toxicology, IU School of Medicine, Indianapolis, IN, United States; Indiana Clinical and Translational Institute, IU School of Medicine, Indianapolis, IN, United States
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21
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Alon M, Arafeh R, Lee JS, Madan S, Kalaora S, Nagler A, Abgarian T, Greenberg P, Ruppin E, Samuels Y. CAPN1 is a novel binding partner and regulator of the tumor suppressor NF1 in melanoma. Oncotarget 2018; 9:31264-31277. [PMID: 30131853 PMCID: PMC6101293 DOI: 10.18632/oncotarget.25805] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 07/05/2018] [Indexed: 11/25/2022] Open
Abstract
Neurofibromin 1 (NF1), a tumor suppressor that negatively regulates RAS through its GTPase activity, is highly mutated in various types of sporadic human cancers, including melanoma. However, the binding partners of NF1 and the pathways in which it is involved in melanoma have not been characterized in an in depth manner. Utilizing a mass spectrometry analysis of NF1 binding partners, we revealed Calpain1 (CAPN1), a calcium-dependent neutral cysteine protease, as a novel NF1 binding partner that regulates NF1 degradation in melanoma cells. ShRNA-mediated knockdown of CAPN1 or treatment with a CAPN1 inhibitor stabilizes NF1 protein levels, downregulates AKT signaling and melanoma cell growth. Combination treatment of Calpain inhibitor I with MEKi Trametinib in different melanoma cells is more effective in reducing melanoma cell growth compared to treatment with Trametinib alone, suggesting that this combination may have a therapeutic potential in melanoma. This novel mechanism for regulating NF1 in melanoma provides a molecular basis for targeting CAPN1 in order to stabilize NF1 levels and, in doing so, suppressing Ras activation; this mechanism can be exploited therapeutically in melanoma and other cancers.
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Affiliation(s)
- Michal Alon
- Molecular Cell Biology Department, Weizmann Institute of Science, Rehovot, Israel
| | - Rand Arafeh
- Molecular Cell Biology Department, Weizmann Institute of Science, Rehovot, Israel
| | - Joo Sang Lee
- Center for Bioinformatics and Computational Biology, The University of Maryland, College Park, Maryland, USA
- Cancer Data Science Lab, National Cancer Institute, National Institute of Health, Bethesda, Maryland, USA
| | - Sanna Madan
- Center for Bioinformatics and Computational Biology, The University of Maryland, College Park, Maryland, USA
- Cancer Data Science Lab, National Cancer Institute, National Institute of Health, Bethesda, Maryland, USA
| | - Shelly Kalaora
- Molecular Cell Biology Department, Weizmann Institute of Science, Rehovot, Israel
| | - Adi Nagler
- Molecular Cell Biology Department, Weizmann Institute of Science, Rehovot, Israel
| | - Tereza Abgarian
- Molecular Cell Biology Department, Weizmann Institute of Science, Rehovot, Israel
| | - Polina Greenberg
- Molecular Cell Biology Department, Weizmann Institute of Science, Rehovot, Israel
| | - Eytan Ruppin
- Center for Bioinformatics and Computational Biology, The University of Maryland, College Park, Maryland, USA
- Cancer Data Science Lab, National Cancer Institute, National Institute of Health, Bethesda, Maryland, USA
| | - Yardena Samuels
- Molecular Cell Biology Department, Weizmann Institute of Science, Rehovot, Israel
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22
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Clinical characteristics and NF1 gene mutation analysis of three successive generations in three different Indian families with neurofibromatosis type 1 and peripheral nerve sheath tumours. J Clin Neurosci 2018; 53:62-68. [PMID: 29680440 DOI: 10.1016/j.jocn.2018.04.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 03/05/2018] [Accepted: 04/02/2018] [Indexed: 11/21/2022]
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23
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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] [Key Words] [MESH Headings] [Grants] [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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Neurocristopathies: New insights 150 years after the neural crest discovery. Dev Biol 2018; 444 Suppl 1:S110-S143. [PMID: 29802835 DOI: 10.1016/j.ydbio.2018.05.013] [Citation(s) in RCA: 104] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 05/16/2018] [Accepted: 05/17/2018] [Indexed: 12/12/2022]
Abstract
The neural crest (NC) is a transient, multipotent and migratory cell population that generates an astonishingly diverse array of cell types during vertebrate development. These cells, which originate from the ectoderm in a region lateral to the neural plate in the neural fold, give rise to neurons, glia, melanocytes, chondrocytes, smooth muscle cells, odontoblasts and neuroendocrine cells, among others. Neurocristopathies (NCP) are a class of pathologies occurring in vertebrates, especially in humans that result from the abnormal specification, migration, differentiation or death of neural crest cells during embryonic development. Various pigment, skin, thyroid and hearing disorders, craniofacial and heart abnormalities, malfunctions of the digestive tract and tumors can also be considered as neurocristopathies. In this review we revisit the current classification and propose a new way to classify NCP based on the embryonic origin of the affected tissues, on recent findings regarding the molecular mechanisms that drive NC formation, and on the increased complexity of current molecular embryology techniques.
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25
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Abstract
In Neurofibromatosis 1 (NF1) germ line loss of function mutations result in reduction of cellular neurofibromin content (NF1+/-, NF1 haploinsufficiency). The Ras-GAP neurofibromin is a very large cytoplasmic protein (2818 AA, 319 kDa) involved in the RAS-MAPK pathway. Aside from regulation of proliferation, it is involved in mechanosensoric of cells. We investigated neurofibromin replacement in cultured human fibroblasts showing reduced amount of neurofibromin. Full length neurofibromin was produced recombinantly in insect cells and purified. Protein transduction into cultured fibroblasts was performed employing cell penetrating peptides along with photochemical internalization. This combination of transduction strategies ensures the intracellular uptake and the translocation to the cytoplasm of neurofibromin. The transduced neurofibromin is functional, indicated by functional rescue of reduced mechanosensoric blindness and reduced RasGAP activity in cultured fibroblasts of NF1 patients or normal fibroblasts treated by NF1 siRNA. Our study shows that recombinant neurofibromin is able to revert cellular effects of NF1 haploinsuffiency in vitro, indicating a use of protein transduction into cells as a potential treatment strategy for the monogenic disease NF1.
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26
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Allaway RJ, Wood MD, Downey SL, Bouley SJ, Traphagen NA, Wells JD, Batra J, Melancon SN, Ringelberg C, Seibel W, Ratner N, Sanchez Y. Exploiting mitochondrial and metabolic homeostasis as a vulnerability in NF1 deficient cells. Oncotarget 2018; 9:15860-15875. [PMID: 29662612 PMCID: PMC5882303 DOI: 10.18632/oncotarget.19335] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 07/09/2017] [Indexed: 11/26/2022] Open
Abstract
Neurofibromatosis type 1 is a disease caused by mutation of neurofibromin 1 (NF1), loss of which results in hyperactive Ras signaling and a concomitant increase in cell proliferation and survival. Patients with neurofibromatosis type 1 frequently develop tumors such as plexiform neurofibromas and malignant peripheral nerve sheath tumors. Mutation of NF1 or loss of the NF1 protein is also observed in glioblastoma, lung adenocarcinoma, and ovarian cancer among other sporadic cancers. A therapy that selectively targets NF1 deficient tumors would substantially advance our ability to treat these malignancies. To address the need for these therapeutics, we developed and conducted a synthetic lethality screen to discover molecules that target yeast lacking the homolog of NF1, IRA2. One of the lead candidates that was observed to be synthetic lethal with ira2Δ yeast is Y100. Here, we describe the mechanisms by which Y100 targets ira2Δ yeast and NF1-deficient tumor cells. Y100 treatment disrupted proteostasis, metabolic homeostasis, and induced the formation of mitochondrial superoxide in NF1-deficient cancer cells. Previous studies also indicate that NF1/Ras-dysregulated tumors may be sensitive to modulators of oxidative and ER stress. We hypothesize that the use of Y100 and molecules with related mechanisms of action represent a feasible therapeutic strategy for targeting NF1 deficient cells.
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Affiliation(s)
- Robert J. Allaway
- Department of Molecular and Systems Biology, Geisel School of Medicine, Dartmouth College, Hanover, NH 03755, USA
| | - Matthew D. Wood
- Department of Pharmacology and Toxicology, Geisel School of Medicine, Dartmouth College, Hanover, NH 03755, USA
- Current address: Department of Pathology, University of California San Francisco, San Francisco, CA 94143, USA
| | - Sondra L. Downey
- Department of Pharmacology and Toxicology, Geisel School of Medicine, Dartmouth College, Hanover, NH 03755, USA
| | - Stephanie J. Bouley
- Department of Molecular and Systems Biology, Geisel School of Medicine, Dartmouth College, Hanover, NH 03755, USA
| | - Nicole A. Traphagen
- Department of Molecular and Systems Biology, Geisel School of Medicine, Dartmouth College, Hanover, NH 03755, USA
| | - Jason D. Wells
- Department of Epidemiology, Geisel School of Medicine, Dartmouth College, Hanover, NH 03755, USA
| | - Jaya Batra
- Department of Pharmacology and Toxicology, Geisel School of Medicine, Dartmouth College, Hanover, NH 03755, USA
- Current address: Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Sir Norman Melancon
- Department of Pharmacology and Toxicology, Geisel School of Medicine, Dartmouth College, Hanover, NH 03755, USA
- Current address: Vanderbilt School of Medicine, Nashville, TN 37232, USA
| | - Carol Ringelberg
- Department of Molecular and Systems Biology, Geisel School of Medicine, Dartmouth College, Hanover, NH 03755, USA
- Bioinformatics Shared Resource, Norris Cotton Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, NH 03756, USA
| | - William Seibel
- Division of Oncology, Cincinnati Children’s Hospital Medical Center, Cancer and Blood Diseases Institute, Cincinnati, OH 45229, USA
| | - Nancy Ratner
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children’s Hospital Medical Center, Cancer and Blood Diseases Institute, Cincinnati, OH 45229, USA
| | - Yolanda Sanchez
- Department of Molecular and Systems Biology, Geisel School of Medicine, Dartmouth College, Hanover, NH 03755, USA
- Norris Cotton Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, NH 03756, USA
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27
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Zhikrivetskaya SO, Snezhkina AV, Zaretsky AR, Alekseev BY, Pokrovsky AV, Golovyuk AL, Melnikova NV, Stepanov OA, Kalinin DV, Moskalev AA, Krasnov GS, Dmitriev AA, Kudryavtseva AV. Molecular markers of paragangliomas/pheochromocytomas. Oncotarget 2017; 8:25756-25782. [PMID: 28187001 PMCID: PMC5421967 DOI: 10.18632/oncotarget.15201] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Accepted: 01/23/2017] [Indexed: 12/14/2022] Open
Abstract
Paragangliomas/pheochromocytomas comprise rare tumors that arise from the extra-adrenal paraganglia, with an incidence of about 2 to 8 per million people each year. Approximately 40% of cases are due to genetic mutations in at least one out of more than 30 causative genes. About 25-30% of pheochromocytomas/paragangliomas develop under the conditions of a hereditary tumor syndrome a third of which are caused by mutations in the VHL gene. Together, the gene mutations in this disorder have implicated multiple processes including signaling pathways, translation initiation, hypoxia regulation, protein synthesis, differentiation, survival, proliferation, and cell growth. The present review contemplates the mutations associated with the development of pheochromocytomas/paragangliomas and their potential to serve as specific markers of these tumors and their progression. These data will improve our understanding of the pathogenesis of these tumors and likely reveal certain features that may be useful for early diagnostics, malignancy prognostics, and the determination of new targets for disease therapeutics.
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Affiliation(s)
| | | | - Andrew R Zaretsky
- M.M. Shemyakin - Yu.A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Boris Y Alekseev
- National Medical Research Radiological Center, Ministry of Health of the Russian Federation, Moscow, Russia
| | | | | | - Nataliya V Melnikova
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Oleg A Stepanov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
- National Medical Research Radiological Center, Ministry of Health of the Russian Federation, Moscow, Russia
| | | | - Alexey A Moskalev
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - George S Krasnov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Alexey A Dmitriev
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Anna V Kudryavtseva
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
- National Medical Research Radiological Center, Ministry of Health of the Russian Federation, Moscow, Russia
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28
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Ricker CA, Pan Y, Gutmann DH, Keller C. Challenges in Drug Discovery for Neurofibromatosis Type 1-Associated Low-Grade Glioma. Front Oncol 2016; 6:259. [PMID: 28066715 PMCID: PMC5167692 DOI: 10.3389/fonc.2016.00259] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Accepted: 12/05/2016] [Indexed: 01/08/2023] Open
Abstract
Neurofibromatosis type 1 (NF1) is an autosomal dominant disorder that results from germline mutations of the NF1 gene, creating a predisposition to low-grade gliomas (LGGs; pilocytic astrocytoma) in young children. Insufficient data and resources represent major challenges to identifying the best possible drug therapies for children with this tumor. Herein, we summarize the currently available cell lines, genetically engineered mouse models, and therapeutic targets for these LGGs. Conspicuously absent are human tumor-derived cell lines or patient-derived xenograft models for NF1-LGG. New collaborative initiatives between patients and their families, research groups, and pharmaceutical companies are needed to create transformative resources and broaden the knowledge base relevant to identifying cooperating genetic drivers and possible drug therapeutics for this common pediatric brain tumor.
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Affiliation(s)
- Cora A Ricker
- Children's Cancer Therapy Development Institute , Beaverton, OR , USA
| | - Yuan Pan
- Washington University School of Medicine , St. Louis, MO , USA
| | - David H Gutmann
- Washington University School of Medicine , St. Louis, MO , USA
| | - Charles Keller
- Children's Cancer Therapy Development Institute , Beaverton, OR , USA
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29
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Wang S, Ma G, Zhu H, Lv C, Chu H, Tong N, Wu D, Qiang F, Gong W, Zhao Q, Tao G, Zhou J, Zhang Z, Wang M. miR-107 regulates tumor progression by targeting NF1 in gastric cancer. Sci Rep 2016; 6:36531. [PMID: 27827403 PMCID: PMC5101511 DOI: 10.1038/srep36531] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 10/17/2016] [Indexed: 12/20/2022] Open
Abstract
Our previous genome-wide miRNA microarray study revealed that miR-107 was upregulated in gastric cancer (GC). In this study we aimed to explore its biological role in the pathogenesis of GC. Integrating in silico prediction algorithms with western blotting assays revealed that miR-107 inhibition enhanced NF1 (neurofibromin 1) mRNA and protein levels, suggesting that NF1 is one of miR-107 targets in GC. Luciferase reporter assay revealed that miR-107 suppressed NF1 expression by binding to the first potential binding site within the 3′-UTR of NF1 mRNA. mRNA stable assay indicated this binding could result in NF1 mRNA instability, which might contribute to its abnormal protein expression. Functional analyses such as cell growth, transwell migration and invasion assays were used to investigate the role of interaction between miR-107 and its target on GC development and progression. Moreover, We investigated the association between the clinical phenotype and the status of miR-107 expression in 55 GC tissues, and found the high expression contributed to the tumor size and depth of invasion. The results exhibited that down regulation of miR-107 opposed cell growth, migration, and invasion, whereas NF1 repression promoted these phenotypes. Our findings provide a mechanism by which miR-107 regulates NF1 in GC, as well as highlight the importance of interaction between miR-107 and NF1 in GC development and progression.
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Affiliation(s)
- Shizhi Wang
- Department of Environmental Genomics, Jiangsu Key Laboratory of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center For Cancer Personalized Medicine, Nanjing Medical University, Nanjing, China.,Department of Genetic Toxicology, the Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing, China.,Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing, China
| | - Gaoxiang Ma
- Department of Environmental Genomics, Jiangsu Key Laboratory of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center For Cancer Personalized Medicine, Nanjing Medical University, Nanjing, China.,Department of Genetic Toxicology, the Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Haixia Zhu
- Core Laboratory, Nantong Tumor Hospital, Nantong, China
| | - Chunye Lv
- Department of Environmental Genomics, Jiangsu Key Laboratory of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center For Cancer Personalized Medicine, Nanjing Medical University, Nanjing, China.,Department of General Surgery, The Affiliated Jiangning Hospital of Nanjing Medical University, Nanjing, China
| | - Haiyan Chu
- Department of Environmental Genomics, Jiangsu Key Laboratory of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center For Cancer Personalized Medicine, Nanjing Medical University, Nanjing, China.,Department of Genetic Toxicology, the Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Na Tong
- Department of Environmental Genomics, Jiangsu Key Laboratory of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center For Cancer Personalized Medicine, Nanjing Medical University, Nanjing, China.,Department of Genetic Toxicology, the Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Dongmei Wu
- Department of Environmental Genomics, Jiangsu Key Laboratory of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center For Cancer Personalized Medicine, Nanjing Medical University, Nanjing, China.,Department of Genetic Toxicology, the Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Fulin Qiang
- Department of Environmental Genomics, Jiangsu Key Laboratory of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center For Cancer Personalized Medicine, Nanjing Medical University, Nanjing, China.,Core Laboratory, Nantong Tumor Hospital, Nantong, China
| | - Weida Gong
- Department of General Surgery, Yixing Cancer Hospital, Yixing, China
| | - Qinghong Zhao
- Department of General Surgery, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Guoquan Tao
- Department of General Surgery, Huai-An First People's Hospital Affiliated to Nanjing Medical University, Huai-An, China
| | - Jianwei Zhou
- Department of Molecular Cell Biology and Toxicology, Cancer Center, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Zhengdong Zhang
- Department of Environmental Genomics, Jiangsu Key Laboratory of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center For Cancer Personalized Medicine, Nanjing Medical University, Nanjing, China.,Department of Genetic Toxicology, the Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Meilin Wang
- Department of Environmental Genomics, Jiangsu Key Laboratory of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center For Cancer Personalized Medicine, Nanjing Medical University, Nanjing, China.,Department of Genetic Toxicology, the Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing, China
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30
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Hennig A, Markwart R, Wolff K, Schubert K, Cui Y, Prior IA, Esparza-Franco MA, Ladds G, Rubio I. Feedback activation of neurofibromin terminates growth factor-induced Ras activation. Cell Commun Signal 2016; 14:5. [PMID: 26861207 PMCID: PMC4746934 DOI: 10.1186/s12964-016-0128-z] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 02/03/2016] [Indexed: 02/08/2023] Open
Abstract
Background Growth factors induce a characteristically short-lived Ras activation in cells emerging from quiescence. Extensive work has shown that transient as opposed to sustained Ras activation is critical for the induction of mitogenic programs. Mitogen-induced accumulation of active Ras-GTP results from increased nucleotide exchange driven by the nucleotide exchange factor Sos. In contrast, the mechanism accounting for signal termination and prompt restoration of basal Ras-GTP levels is unclear, but has been inferred to involve feedback inhibition of Sos. Remarkably, how GTP-hydrolase activating proteins (GAPs) participate in controlling the rise and fall of Ras-GTP levels is unknown. Results Monitoring nucleotide exchange of Ras in permeabilized cells we find, unexpectedly, that the decline of growth factor-induced Ras-GTP levels proceeds in the presence of unabated high nucleotide exchange, pointing to GAP activation as a major mechanism of signal termination. Experiments with non-hydrolysable GTP analogues and mathematical modeling confirmed and rationalized the presence of high GAP activity as Ras-GTP levels decline in a background of high nucleotide exchange. Using pharmacological and genetic approaches we document a raised activity of the neurofibromatosis type I tumor suppressor Ras-GAP neurofibromin and an involvement of Rsk1 and Rsk2 in the down-regulation of Ras-GTP levels. Conclusions Our findings show that, in addition to feedback inhibition of Sos, feedback stimulation of the RasGAP neurofibromin enforces termination of the Ras signal in the context of growth-factor signaling. These findings ascribe a precise role to neurofibromin in growth factor-dependent control of Ras activity and illustrate how, by engaging Ras-GAP activity, mitogen-challenged cells play safe to ensure a timely termination of the Ras signal irrespectively of the reigning rate of nucleotide exchange. Electronic supplementary material The online version of this article (doi:10.1186/s12964-016-0128-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Anne Hennig
- Institute of Molecular Cell Biology, Center for Molecular Biomedicine, University Hospital, Hans-Knöll-Str.2, 07745, Jena, Germany.
| | - Robby Markwart
- Institute of Molecular Cell Biology, Center for Molecular Biomedicine, University Hospital, Hans-Knöll-Str.2, 07745, Jena, Germany.
| | - Katharina Wolff
- Institute of Molecular Cell Biology, Center for Molecular Biomedicine, University Hospital, Hans-Knöll-Str.2, 07745, Jena, Germany.
| | - Katja Schubert
- Institute of Molecular Cell Biology, Center for Molecular Biomedicine, University Hospital, Hans-Knöll-Str.2, 07745, Jena, Germany.
| | - Yan Cui
- Leibniz Institute for Age Research - Fritz Lipmann Institute, 07745, Jena, Germany.
| | - Ian A Prior
- Division of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, L69 3BX, UK.
| | | | - Graham Ladds
- Department of Pharmacology, University of Cambridge, Cambridge, CB2 1PD, UK.
| | - Ignacio Rubio
- Institute of Molecular Cell Biology, Center for Molecular Biomedicine, University Hospital, Hans-Knöll-Str.2, 07745, Jena, Germany. .,Center for Sepsis Control and Care, University Hospital, 07747, Jena, Germany.
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31
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RasGRP1 overexpression in T-ALL increases basal nucleotide exchange on Ras rendering the Ras/PI3K/Akt pathway responsive to protumorigenic cytokines. Oncogene 2015; 35:3658-68. [PMID: 26549032 DOI: 10.1038/onc.2015.431] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Revised: 08/31/2015] [Accepted: 10/05/2015] [Indexed: 12/25/2022]
Abstract
Ras GTPases are activated by RasGEFs and inactivated by RasGAPs, which stimulate the hydrolysis of RasGTP to inactive RasGDP. GTPase-impairing somatic mutations in RAS genes, such as KRAS(G12D), are among the most common oncogenic events in metastatic cancer. A different type of cancer Ras signal, driven by overexpression of the RasGEF RasGRP1 (Ras guanine nucleotide-releasing protein 1), was recently implicated in pediatric T-cell acute lymphoblastic leukemia (T-ALL) patients and murine models, in which RasGRP1 T-ALLs expand in response to treatment with interleukins (ILs) 2, 7 and 9. Here, we demonstrate that IL-2/7/9 stimulation activates Erk and Akt pathways downstream of Ras in RasGRP1 T-ALL but not in normal thymocytes. In normal lymphocytes, RasGRP1 is recruited to the membrane by diacylglycerol (DAG) in a phospholipase C-γ (PLCγ)-dependent manner. Surprisingly, we find that leukemic RasGRP1-triggered Ras-Akt signals do not depend on acute activation of PLCγ to generate DAG but rely on baseline DAG levels instead. In agreement, using three distinct assays that measure different aspects of the RasGTP/GDP cycle, we established that overexpression of RasGRP1 in T-ALLs results in a constitutively high GTP-loading rate of Ras, which is constantly counterbalanced by hydrolysis of RasGTP. KRAS(G12D) T-ALLs do not show constitutive GTP loading of Ras. Thus, we reveal an entirely novel type of leukemogenic Ras signals that is based on a RasGRP1-driven increased in flux through the RasGTP/GDP cycle, which is mechanistically very different from KRAS(G12D) signals. Our studies highlight the dynamic balance between RasGEF and RasGAP in these T-ALLs and put forth a new model in which IL-2/7/9 decrease RasGAP activity.
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32
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Gripp KW, Sol-Church K, Smpokou P, Graham GE, Stevenson DA, Hanson H, Viskochil DH, Baker LC, Russo B, Gardner N, Stabley DL, Kolbe V, Rosenberger G. An attenuated phenotype of Costello syndrome in three unrelated individuals with a HRAS c.179G>A (p.Gly60Asp) mutation correlates with uncommon functional consequences. Am J Med Genet A 2015; 167A:2085-97. [PMID: 25914166 DOI: 10.1002/ajmg.a.37128] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Accepted: 04/06/2015] [Indexed: 12/20/2022]
Abstract
Heterozygous germline mutations in the proto-oncogene HRAS cause Costello syndrome (CS), an intellectual disability condition with severe failure to thrive, cardiac abnormalities, predisposition to tumors, and neurologic abnormalities. More than 80% of patients share the HRAS mutation c.34G>A (p.Gly12Ser) associated with the typical, relatively homogeneous phenotype. Rarer mutations occurred in individuals with an attenuated phenotype and less characteristic facial features. Most pathogenic HRAS alterations affect hydrolytic HRAS activity resulting in constitutive activation. "Gain-of-function" and "hyperactivation" concerning downstream pathways are widely used to explain the molecular basis and dysregulation of the RAS-MAPK pathway is the biologic mechanism shared amongst rasopathies. Panel testing for rasopathies identified a novel HRAS mutation (c.179G>A; p.Gly60Asp) in three individuals with attenuated features of Costello syndrome. De novo paternal origin occurred in two, transmission from a heterozygous mother in the third. Individuals showed subtle facial features; curly hair and relative macrocephaly were seen in three; atrial tachycardia and learning difficulties in two, and pulmonic valve dysplasia and mildly thickened left ventricle in one. None had severe failure to thrive, intellectual disability or cancer, underscoring the need to consider HRAS mutations in individuals with an unspecific rasopathy phenotype. Functional studies revealed strongly increased HRAS(Gly60Asp) binding to RAF1, but not to other signaling effectors. Hyperactivation of the MAPK downstream signaling pathways was absent. Our results indicate that an increase in the proportion of activated RAS downstream signaling components does not entirely explain the molecular basis of CS. We conclude that the phenotypic variability in CS recapitulates variable qualities of molecular dysfunction.
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Affiliation(s)
- Karen W Gripp
- Division of Medical Genetics, A. I. duPont Hospital for Children, Wilmington, Delaware
| | - Katia Sol-Church
- Center for Applied Clinical Genomics, A. I. duPont Hospital for Children, Wilmington, Delaware
| | - Patroula Smpokou
- Division of Genetics and Metabolism, Children's National Health System, Washington, District of Columbia
| | - Gail E Graham
- Department of Genetics, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada
| | - David A Stevenson
- Division of Medical Genetics, Stanford University, Stanford, California
| | - Heather Hanson
- Division of Medical Genetics, Department of Pediatrics, University of Utah, Salt Lake City, Utah
| | - David H Viskochil
- Division of Medical Genetics, Department of Pediatrics, University of Utah, Salt Lake City, Utah
| | - Laura C Baker
- Division of Medical Genetics, A. I. duPont Hospital for Children, Wilmington, Delaware
| | - Bridget Russo
- Center for Applied Clinical Genomics, A. I. duPont Hospital for Children, Wilmington, Delaware
| | - Nick Gardner
- Center for Applied Clinical Genomics, A. I. duPont Hospital for Children, Wilmington, Delaware
| | - Deborah L Stabley
- Center for Applied Clinical Genomics, A. I. duPont Hospital for Children, Wilmington, Delaware
| | - Verena Kolbe
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Georg Rosenberger
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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33
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Bloomfield G, Traynor D, Sander SP, Veltman DM, Pachebat JA, Kay RR. Neurofibromin controls macropinocytosis and phagocytosis in Dictyostelium. eLife 2015; 4. [PMID: 25815683 PMCID: PMC4374526 DOI: 10.7554/elife.04940] [Citation(s) in RCA: 97] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2014] [Accepted: 03/06/2015] [Indexed: 02/06/2023] Open
Abstract
Cells use phagocytosis and macropinocytosis to internalise bulk material, which in phagotrophic organisms supplies the nutrients necessary for growth. Wildtype Dictyostelium amoebae feed on bacteria, but for decades laboratory work has relied on axenic mutants that can also grow on liquid media. We used forward genetics to identify the causative gene underlying this phenotype. This gene encodes the RasGAP Neurofibromin (NF1). Loss of NF1 enables axenic growth by increasing fluid uptake. Mutants form outsized macropinosomes which are promoted by greater Ras and PI3K activity at sites of endocytosis. Relatedly, NF1 mutants can ingest larger-than-normal particles using phagocytosis. An NF1 reporter is recruited to nascent macropinosomes, suggesting that NF1 limits their size by locally inhibiting Ras signalling. Our results link NF1 with macropinocytosis and phagocytosis for the first time, and we propose that NF1 evolved in early phagotrophs to spatially modulate Ras activity, thereby constraining and shaping their feeding structures. DOI:http://dx.doi.org/10.7554/eLife.04940.001 Dictyostelium amoebae are microbes that feed on bacteria living in the soil. They are unusual in that the amoebae can survive and grow in a single-celled form, but when food is scarce, many individual cells can gather together to form a simple multicellular organism. To feed on bacteria, the amoebae use a process called phagocytosis, which starts with the membrane that surrounds the cell growing outwards to completely surround the bacteria. This leads to the bacteria entering the amoeba within a membrane compartment called a vesicle, where they are broken down into small molecules by enzymes. The cells can also take up fluids and dissolved molecules using a similar process called macropinocytosis. With its short and relatively simple lifestyle, Dictyostelium is often used in research to study phagocytosis, cell movement and other processes that are also found in larger organisms. For example, some immune cells in animals use phagocytosis to capture and destroy invading microbes. Most studies using Dictyostelium as a model have used amoebae with genetic mutations that allow them to be grown in liquid cultures in the laboratory without needing to feed on bacteria. The mutations allow the ‘mutant’ amoebae to take up more liquid and dissolved nutrients by macropinocytosis, but it is not known where in the genome these mutations are. Here, Bloomfield et al. used genome sequencing to reveal that these mutations alter a gene that encodes a protein called Neurofibromin. The experiments show that the loss of Neurofibromin increases the amount of fluid taken up by the amoebae through macropinocytosis, and also enables the amoebae to take up larger-than-normal particles during phagocytosis. The experiments suggest that Neurofibromin controls both phagocytosis and macropinocytosis by inhibiting the activity of another protein called Ras. Neurofibromin is found in animals and many other organisms so Bloomfield et al. propose that it is an ancient protein that evolved in early single-celled organisms to control the size and shape of their feeding structures. In humans, mutations in the gene that encodes the Neurofibromin protein can lead to the development of a severe disorder—called Neurofibromatosis type 1—in which tumours form in the nervous system. Given that tumour cells can use phagocytosis and macropinocytosis to gain nutrients as they grow, understanding how this protein works in the Dictyostelium amoebae may help to inform future efforts to develop treatments for this human disease. DOI:http://dx.doi.org/10.7554/eLife.04940.002
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Affiliation(s)
| | - David Traynor
- MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Sophia P Sander
- MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Douwe M Veltman
- MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Justin A Pachebat
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom
| | - Robert R Kay
- MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
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Taha H, Yehia M, Mahmoud M, El-Beltagy M, Ghabriel M, El-Naggar S. Incidence of kiaa1549-braf fusion gene in Egyptian pediatric low grade glioma. Clin Transl Med 2015; 4:10. [PMID: 25883769 PMCID: PMC4392037 DOI: 10.1186/s40169-015-0052-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Accepted: 02/03/2015] [Indexed: 01/04/2023] Open
Abstract
Background Low grade gliomas are the most common brain tumor in children. Tandem duplication involving the KIAA1549 and the BRAF kinase genes results in a gene fusion that has been recently characterized in a subset of low grade glioma While there is no clear evidence that the KIAA1549-BRAF gene fusion has an effect on prognosis, it is an attractive target for therapy development and as a diagnostic tool. Methods In the current study we examine the prevalence of KIAA1549-BRAF gene fusion in pediatric patients diagnosed with low grade glioma in the Egyptian population and its relationship to clinical and histological subtypes. Sixty patients between the ages of 1 to 18 years were analyzed for the presence of KIAA1549-BRAF fusion gene products using reverse transcription-PCR and sequencing. The clinicopathologic tumor characteristics were then analyzed in relation to the different fusion genes. Results KIAA1549-BRAF fusion genes were detected in 56.6% of patients. They were primarily associated with pilocytic astrocytoma (74.2%) and pilomyxoid astrocytoma (60%). Translocation 15–9 was the most common, representing (55.8%) of all positive samples followed by 16–9 (26.4%) and 16–11 (8.8%). Pilocytic astrocytomas presented primarily with 15–9 (32.2%), 16–9 (25.8%) and 16–11 (6.4%) while pilomyxoid astrocytomas presented with 15–9 (46.6%), 16–9 (6.6%) and 16–11 (6.6%) translocations. Conclusion Gene fusion is found to be significantly increased in cerebellar pilocytic astrocytoma tumors. Furthermore, 15–9 was found to have a higher incidence among our cohort compared to previous studies. While most of the gene fusion positive pilomyxoid astrocytomas were 15–9, we find the association none significant.
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Affiliation(s)
- Hala Taha
- Department of Pathology, Children's Cancer Hospital Egypt 57357, P.O Box 11441, 1 Sekeat El-Imam, Cairo, Egypt
| | - Maha Yehia
- Department of Pathology, Children's Cancer Hospital Egypt 57357, P.O Box 11441, 1 Sekeat El-Imam, Cairo, Egypt
| | - Madeha Mahmoud
- Department of Pediatric Oncology, Children's Cancer Hospital Egypt 57357, P.O Box 11441, 1 Sekeat El-Imam, Cairo, Egypt
| | - Mohamed El-Beltagy
- Department of Neurosurgery, Children's Cancer Hospital Egypt 57357, P.O Box 11441, 1 Sekeat El-Imam, Cairo, Egypt
| | - Myret Ghabriel
- Basic Research Department, Children's Cancer Hospital Egypt 57357, P.O Box 11441, 1 Sekeat El-Imam, Cairo, Egypt
| | - Shahenda El-Naggar
- Basic Research Department, Children's Cancer Hospital Egypt 57357, P.O Box 11441, 1 Sekeat El-Imam, Cairo, Egypt
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Okada T, Sinha S, Esposito I, Schiavon G, López-Lago MA, Su W, Pratilas CA, Abele C, Hernandez JM, Ohara M, Okada M, Viale A, Heguy A, Socci ND, Sapino A, Seshan VE, Long S, Inghirami G, Rosen N, Giancotti FG. The Rho GTPase Rnd1 suppresses mammary tumorigenesis and EMT by restraining Ras-MAPK signalling. Nat Cell Biol 2014; 17:81-94. [PMID: 25531777 DOI: 10.1038/ncb3082] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Accepted: 11/10/2014] [Indexed: 12/11/2022]
Abstract
We identified the Rho GTPase Rnd1 as a candidate metastasis suppressor in basal-like and triple-negative breast cancer through bioinformatics analysis. Depletion of Rnd1 disrupted epithelial adhesion and polarity, induced epithelial-to-mesenchymal transition, and cooperated with deregulated expression of c-Myc or loss of p53 to cause neoplastic conversion. Mechanistic studies revealed that Rnd1 suppresses Ras signalling by activating the GAP domain of Plexin B1, which inhibits Rap1. Rap1 inhibition in turn led to derepression of p120 Ras-GAP, which was able to inhibit Ras. Inactivation of Rnd1 in mammary epithelial cells induced highly undifferentiated and invasive tumours in mice. Conversely, Rnd1 expression inhibited spontaneous and experimental lung colonization in mouse models of metastasis. Genomic studies indicated that gene deletion in combination with epigenetic silencing or, more rarely, point mutation inactivates RND1 in human breast cancer. These results reveal a previously unappreciated mechanism through which Rnd1 restrains activation of Ras-MAPK signalling and breast tumour initiation and progression.
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Affiliation(s)
- Tomoyo Okada
- Cell Biology Program, Sloan-Kettering Institute for Cancer Research, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA
| | - Surajit Sinha
- Cell Biology Program, Sloan-Kettering Institute for Cancer Research, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA
| | - Ilaria Esposito
- Cell Biology Program, Sloan-Kettering Institute for Cancer Research, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA
| | - Gaia Schiavon
- Cell Biology Program, Sloan-Kettering Institute for Cancer Research, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA
| | - Miguel A López-Lago
- Cell Biology Program, Sloan-Kettering Institute for Cancer Research, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA
| | - Wenjing Su
- Cell Biology Program, Sloan-Kettering Institute for Cancer Research, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA
| | - Christine A Pratilas
- 1] Molecular Pharmacology and Chemistry Program, Sloan-Kettering Institute for Cancer Research, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA [2] Department of Pediatrics, Memorial Hospital, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA
| | - Cristina Abele
- Department of Biomedical Sciences and Human Oncology, Center of Experimental Medicine and Research, University of Torino, Torino 10126, Italy
| | - Jonathan M Hernandez
- 1] Cell Biology Program, Sloan-Kettering Institute for Cancer Research, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA [2] Department of Surgery, Memorial Hospital, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA
| | - Masahiro Ohara
- Department of Surgical Oncology, Research Institute for Radiation Biology and Medicine, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima 734-8551, Japan
| | - Morihito Okada
- Department of Surgical Oncology, Research Institute for Radiation Biology and Medicine, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima 734-8551, Japan
| | - Agnes Viale
- Genomics Core Facility, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA
| | - Adriana Heguy
- Geoffrey Beene Translational Oncology Core Facility, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA
| | - Nicholas D Socci
- Bioinformatics Core Facility, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA
| | - Anna Sapino
- Department of Medical Sciences, Center of Experimental Medicine and Research, University of Torino, Torino 10126, Italy
| | - Venkatraman E Seshan
- Department of Epidemiology and Biostatistics, Memorial Hospital, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA
| | - Stephen Long
- Structural Biology Program, Sloan-Kettering Institute for Cancer Research, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA
| | - Giorgio Inghirami
- Department of Biomedical Sciences and Human Oncology, Center of Experimental Medicine and Research, University of Torino, Torino 10126, Italy
| | - Neal Rosen
- 1] Molecular Pharmacology and Chemistry Program, Sloan-Kettering Institute for Cancer Research, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA [2] Department of Medicine, Memorial Hospital, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA
| | - Filippo G Giancotti
- Cell Biology Program, Sloan-Kettering Institute for Cancer Research, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA
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de Bruin EC, Cowell C, Warne PH, Jiang M, Saunders RE, Melnick MA, Gettinger S, Walther Z, Wurtz A, Heynen GJ, Heideman DA, Gómez-Román J, García-Castaño A, Gong Y, Ladanyi M, Varmus H, Bernards R, Smit EF, Politi K, Downward J. Reduced NF1 expression confers resistance to EGFR inhibition in lung cancer. Cancer Discov 2014; 4:606-19. [PMID: 24535670 PMCID: PMC4011693 DOI: 10.1158/2159-8290.cd-13-0741] [Citation(s) in RCA: 157] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Activating mutations in the EGF receptor (EGFR) are associated with clinical responsiveness to EGFR tyrosine kinase inhibitors (TKI), such as erlotinib and gefitinib. However, resistance eventually arises, often due to a second EGFR mutation, most commonly T790M. Through a genome-wide siRNA screen in a human lung cancer cell line and analyses of murine mutant EGFR-driven lung adenocarcinomas, we found that erlotinib resistance was associated with reduced expression of neurofibromin, the RAS GTPase-activating protein encoded by the NF1 gene. Erlotinib failed to fully inhibit RAS-ERK signaling when neurofibromin levels were reduced. Treatment of neurofibromin-deficient lung cancers with a MAP-ERK kinase (MEK) inhibitor restored sensitivity to erlotinib. Low levels of NF1 expression were associated with primary and acquired resistance of lung adenocarcinomas to EGFR TKIs in patients. These findings identify a subgroup of patients with EGFR-mutant lung adenocarcinoma who might benefit from combination therapy with EGFR and MEK inhibitors.
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Affiliation(s)
- Elza C. de Bruin
- Signal Transduction, Cancer Research UK London Research Institute, 44 Lincoln’s Inn Fields, London WC2A 3LY, UK
| | - Catherine Cowell
- Signal Transduction, Cancer Research UK London Research Institute, 44 Lincoln’s Inn Fields, London WC2A 3LY, UK
| | - Patricia H. Warne
- Signal Transduction, Cancer Research UK London Research Institute, 44 Lincoln’s Inn Fields, London WC2A 3LY, UK
| | - Ming Jiang
- High Throughput Screening Laboratories, Cancer Research UK London Research Institute, 44 Lincoln’s Inn Fields, London WC2A 3LY, UK
| | - Rebecca E. Saunders
- High Throughput Screening Laboratories, Cancer Research UK London Research Institute, 44 Lincoln’s Inn Fields, London WC2A 3LY, UK
| | - Mary Ann Melnick
- Yale Cancer Center, Yale University School of Medicine, 333 Cedar St, New Haven, CT 06510, USA
| | - Scott Gettinger
- Yale Cancer Center, Yale University School of Medicine, 333 Cedar St, New Haven, CT 06510, USA
- Department of Medicine (Medical Oncology), Yale University School of Medicine, 333 Cedar St, New Haven, CT 06510, USA
| | - Zenta Walther
- Yale Cancer Center, Yale University School of Medicine, 333 Cedar St, New Haven, CT 06510, USA
- Department of Pathology, Yale University School of Medicine, 333 Cedar St, New Haven, CT 06510, USA
| | - Anna Wurtz
- Yale Cancer Center, Yale University School of Medicine, 333 Cedar St, New Haven, CT 06510, USA
| | - Guus J. Heynen
- Division of Molecular Carcinogenesis, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Daniëlle A.M. Heideman
- Department of Pathology, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands
| | - Javier Gómez-Román
- Pathology Service, Universitario Marques de Valdecilla, IFIMAV, Avda Valdecilla s/n, E39008 Santander, Spain
| | - Almudena García-Castaño
- Oncology Service, Hospital Universitario Marques de Valdecilla, IFIMAV, Avda Valdecilla s/n, E39008 Santander, Spain
| | - Yixuan Gong
- Dept of Pathology, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA
| | - Marc Ladanyi
- Dept of Pathology, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA
| | - Harold Varmus
- Cancer Genetics Branch, National Human Genome Research Institute, 50 South Drive, Bethesda, MD 20892, USA
| | - René Bernards
- Division of Molecular Carcinogenesis, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Egbert F. Smit
- Department of Pulmonary Diseases, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands
| | - Katerina Politi
- Yale Cancer Center, Yale University School of Medicine, 333 Cedar St, New Haven, CT 06510, USA
- Department of Medicine (Medical Oncology), Yale University School of Medicine, 333 Cedar St, New Haven, CT 06510, USA
- Department of Pathology, Yale University School of Medicine, 333 Cedar St, New Haven, CT 06510, USA
| | - Julian Downward
- Signal Transduction, Cancer Research UK London Research Institute, 44 Lincoln’s Inn Fields, London WC2A 3LY, UK
- The Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, UK
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Maertens O, Cichowski K. An expanding role for RAS GTPase activating proteins (RAS GAPs) in cancer. Adv Biol Regul 2014; 55:1-14. [PMID: 24814062 DOI: 10.1016/j.jbior.2014.04.002] [Citation(s) in RCA: 119] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Revised: 04/16/2014] [Accepted: 04/16/2014] [Indexed: 10/25/2022]
Abstract
The RAS pathway is one of the most commonly deregulated pathways in human cancer. Mutations in RAS genes occur in nearly 30% of all human tumors. However in some tumor types RAS mutations are conspicuously absent or rare, despite the fact that RAS and downstream effector pathways are hyperactivated. Recently, RAS GTPase Activating Proteins (RAS GAPs) have emerged as an expanding class of tumor suppressors that, when inactivated, provide an alternative mechanism of activating RAS. RAS GAPs normally turn off RAS by catalyzing the hydrolysis of RAS-GTP. As such, the loss of a RAS GAP would be expected to promote excessive RAS activation. Indeed, this is the case for the NF1 gene, which plays an established role in a familial tumor predisposition syndrome and a variety of sporadic cancers. However, there are 13 additional RAS GAP family members in the human genome. We are only now beginning to understand why there are so many RAS GAPs, how they differentially function, and what their potential role(s) in human cancer are. This review will focus on our current understanding of RAS GAPs in human disease and will highlight important outstanding questions.
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Affiliation(s)
- Ophélia Maertens
- Genetics Division, Department of Medicine, Brigham and Women's Hospital, Boston, MA 02115, USA; Harvard Medical School, Boston, MA 02115, USA
| | - Karen Cichowski
- Genetics Division, Department of Medicine, Brigham and Women's Hospital, Boston, MA 02115, USA; Harvard Medical School, Boston, MA 02115, USA; Ludwig Center at Dana-Farber/Harvard Cancer Center, Boston, MA 02115, USA.
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38
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Abstract
The neuroendocrine tumours pheochromocytomas and paragangliomas carry the highest degree of heritability in human neoplasms, enabling genetic alterations to be traced to clinical phenotypes through their transmission in families. Mutations in more than a dozen distinct susceptibility genes have implicated multiple pathways in these tumours, offering insights into kinase downstream signalling interactions and hypoxia regulation, and uncovering links between metabolism, epigenetic remodelling and cell growth. These advances extend to co-occurring tumours, including renal, thyroid and gastrointestinal malignancies. Hereditary pheochromocytomas and paragangliomas are powerful models for recognizing cancer driver events, which can be harnessed for diagnostic purposes and for guiding the future development of targeted therapies.
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Affiliation(s)
- Patricia L M Dahia
- Department of Medicine/Division of Hematology and Medical Oncology, Cancer Therapy and Research Center, Greehey Children Cancer Research Institute, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, Lab 5053-R3, MC 7880, San Antonio-TX 78229-3900, USA
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39
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Dahia PLM. The genetic landscape of pheochromocytomas and paragangliomas: somatic mutations take center stage. J Clin Endocrinol Metab 2013; 98:2679-81. [PMID: 23837189 DOI: 10.1210/jc.2013-2191] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
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40
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Vlachostergios PJ, Voutsadakis IA, Papandreou CN. Mechanisms of proteasome inhibitor-induced cytotoxicity in malignant glioma. Cell Biol Toxicol 2013; 29:199-211. [PMID: 23733249 DOI: 10.1007/s10565-013-9248-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Accepted: 05/23/2013] [Indexed: 12/12/2022]
Abstract
The 26S proteasome constitutes an essential degradation apparatus involved in the consistent recycling of misfolded and damaged proteins inside cells. The aberrant activation of the proteasome has been widely observed in various types of cancers and implicated in the development and progression of carcinogenesis. In the era of targeted therapies, the clinical use of proteasome inhibitors necessitates a better understanding of the molecular mechanisms of cell death responsible for their cytotoxic action, which are reviewed here in the context of sensitization of malignant gliomas, a tumor type particularly refractory to conventional treatments.
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Affiliation(s)
- Panagiotis J Vlachostergios
- Department of Medical Oncology, Faculty of Medicine, University of Thessaly, University Hospital of Larissa, Larissa, 41110, Greece.
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Hollstein PE, Cichowski K. Identifying the Ubiquitin Ligase complex that regulates the NF1 tumor suppressor and Ras. Cancer Discov 2013; 3:880-93. [PMID: 23661552 DOI: 10.1158/2159-8290.cd-13-0146] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The NF1 tumor suppressor protein neurofibromin is a negative regulator of Ras. Neurofibromin is dynamically regulated by the proteasome, and its degradation and reexpression are essential for maintaining appropriate levels of Ras-GTP. Like p53, NF1/neurofibromin can be inactivated in cancer by both mutations and excessive proteasomal destruction; however, little is known about the mechanisms that underlie this latter process. Here, we show that a Cullin 3 (Cul3)/kelch repeat and BTB domain-containing 7 complex controls both the regulated proteasomal degradation of neurofibromin and the pathogenic destabilization of neurofibromin in glioblastomas. Importantly, RNAi-mediated Cul3 ablation and a dominant-negative Cul3 directly stabilize neurofibromin, suppress Ras and extracellular signal-regulated kinase, and inhibit proliferation in an NF1-dependent manner. Moreover, in glioblastomas where neurofibromin is chronically destabilized, Cul3 inhibition restabilizes the protein and suppresses tumor development. Collectively, these studies show a previously unrecognized role for Cul3 in regulating Ras and provide a molecular framework that can be exploited to develop potential cancer therapies.
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Affiliation(s)
- Pablo E Hollstein
- Brigham and Women’s Hospital, 77 Avenue Louis Pasteur, NRB 0458C, Boston, MA 02115, USA
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Li Y, Wang Y. Ras protein/cAMP-dependent protein kinase signaling is negatively regulated by a deubiquitinating enzyme, Ubp3, in yeast. J Biol Chem 2013; 288:11358-65. [PMID: 23476013 DOI: 10.1074/jbc.m112.449751] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Ras proteins and cAMP-dependent protein kinase (protein kinase A, PKA) are important components of a nutrient signaling pathway that mediates cellular responses to glucose in yeast. The molecular mechanisms that regulate Ras/PKA-mediated signaling remain to be fully understood. Here, we provide evidence that Ras/PKA signaling is negatively regulated by a deubiquitinating enzyme, Ubp3. Disrupting the activity of Ubp3 leads to hyperactivation of PKA, as evidenced by much enhanced phosphorylation of PKA substrates, decreased accumulation of glycogen, larger cell size, and increased sensitivity to heat shock. Levels of intracellular cAMP and the active forms of Ras proteins are also elevated in the ubp3Δ mutant. Consistent with a possibility that the increased cAMP is responsible for the abnormal signaling behavior of the ubp3Δ mutant, overexpressing PDE2, which encodes a phosphodiesterase that hydrolyzes cAMP, significantly relieves the cell size increase and heat shock sensitivity of the mutant. Further analysis reveals that Ubp3 interacts with a Ras GTPase-accelerating protein, Ira2, and regulates its level of ubiquitination. Together, our data indicate that Ubp3 is a new regulator of the Ras/PKA signaling pathway and suggest that Ubp3 regulates this pathway by controlling the ubiquitination of Ras GTPase-accelerating protein Ira2.
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Affiliation(s)
- Yang Li
- Department of Biology, Saint Louis University, St. Louis, Missouri 63103, USA
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43
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NMR-based functional profiling of RASopathies and oncogenic RAS mutations. Proc Natl Acad Sci U S A 2013; 110:4574-9. [PMID: 23487764 DOI: 10.1073/pnas.1218173110] [Citation(s) in RCA: 178] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Defects in the RAS small G protein or its associated network of regulatory proteins that disrupt GTPase cycling are a major cause of cancer and developmental RASopathy disorders. Lack of robust functional assays has been a major hurdle in RAS pathway-targeted drug development. We used NMR to obtain detailed mechanistic data on RAS cycling defects conferred by oncogenic mutations, or full-length RASopathy-derived regulatory proteins. By monitoring the conformation of wild-type and oncogenic RAS in real-time, we show that opposing properties integrate with regulators to hyperactivate oncogenic RAS mutants. Q61L and G13D exhibited rapid nucleotide exchange and an unexpected susceptibility to GAP-mediated hydrolysis, in direct contrast with G12V, indicating different approaches must be taken to inhibit these oncoproteins. An NMR methodology was established to directly monitor RAS cycling by intact, multidomain proteins encoded by RASopathy genes in mammalian cell extracts. By measuring GAP activity from tumor cells, we demonstrate how loss of neurofibromatosis type 1 (NF1) increases RAS-GTP levels in NF1-derived cells. We further applied this methodology to profile Noonan Syndrome (NS)-derived SOS1 mutants. Combining NMR with cell-based assays allowed us to differentiate defects in catalysis, allosteric regulation, and membrane targeting of individual mutants, while revealing a membrane-dependent compensatory effect that attenuates dramatic increases in RAS activation shown by Y337C, L550P, and I252T. Our NMR method presents a precise and robust measure of RAS activity, providing mechanistic insights that facilitate discovery of therapeutics targeted against the RAS signaling network.
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Maertens O, Johnson B, Hollstein P, Frederick DT, Cooper ZA, Messiaen L, Bronson RT, McMahon M, Granter S, Flaherty K, Wargo JA, Marais R, Cichowski K. Elucidating distinct roles for NF1 in melanomagenesis. Cancer Discov 2013; 3:338-49. [PMID: 23171796 PMCID: PMC3595355 DOI: 10.1158/2159-8290.cd-12-0313] [Citation(s) in RCA: 180] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
BRAF mutations play a well-established role in melanomagenesis; however, without additional genetic alterations, tumor development is restricted by oncogene-induced senescence (OIS). Here, we show that mutations in the NF1 tumor suppressor gene cooperate with BRAF mutations in melanomagenesis by preventing OIS. In a genetically engineered mouse model, Nf1 mutations suppress Braf-induced senescence, promote melanocyte hyperproliferation, and enhance melanoma development. Nf1 mutations function by deregulating both phosphoinositide 3-kinase and extracellular signal-regulated kinase pathways. As such, Nf1/Braf-mutant tumors are resistant to BRAF inhibitors but are sensitive to combined inhibition of mitogen-activated protein/extracellular signal-regulated kinase kinase and mTOR. Importantly, NF1 is mutated or suppressed in human melanomas that harbor concurrent BRAF mutations, NF1 ablation decreases the sensitivity of melanoma cell lines to BRAF inhibitors, and NF1 is lost in tumors from patients following treatment with these agents. Collectively, these studies provide mechanistic insight into how NF1 cooperates with BRAF mutations in melanoma and show that NF1/neurofibromin inactivation may have an impact on responses to targeted therapies.
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Affiliation(s)
- Ophélia Maertens
- Genetics Division, Department of Medicine, Brigham and Women’s Hospital, Boston MA 02115
- Harvard Medical School, Boston MA 02115
| | - Bryan Johnson
- Genetics Division, Department of Medicine, Brigham and Women’s Hospital, Boston MA 02115
- Harvard Medical School, Boston MA 02115
| | - Pablo Hollstein
- Genetics Division, Department of Medicine, Brigham and Women’s Hospital, Boston MA 02115
- Harvard Medical School, Boston MA 02115
| | - Dennie T. Frederick
- Division of Surgical Oncology, Medical Oncology and Dermatology, Massachusetts General Hospital, Boston, MA 02114
| | - Zachary A. Cooper
- Division of Surgical Oncology, Medical Oncology and Dermatology, Massachusetts General Hospital, Boston, MA 02114
| | - Ludwine Messiaen
- Department of Genetics, Medical Genomics Laboratory, University of Alabama at Birmingham, Birmingham, AL 35242
| | | | - Martin McMahon
- Cancer Research Institute & Department of Cell and Molecular Pharmacology, Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA 94143
| | - Scott Granter
- Harvard Medical School, Boston MA 02115
- Department of Pathology, Brigham and Women's Hospital, Boston, MA 02115
| | - Keith Flaherty
- Division of Surgical Oncology, Medical Oncology and Dermatology, Massachusetts General Hospital, Boston, MA 02114
| | - Jennifer A. Wargo
- Division of Surgical Oncology, Medical Oncology and Dermatology, Massachusetts General Hospital, Boston, MA 02114
| | - Richard Marais
- The Patterson Institute for Cancer Research, The University of Manchester, Manchester, UK
| | - Karen Cichowski
- Genetics Division, Department of Medicine, Brigham and Women’s Hospital, Boston MA 02115
- Harvard Medical School, Boston MA 02115
- Ludwig Center at Dana-Farber/Harvard Cancer Center, Boston, MA 02115
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45
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Abstract
Mutations in the SPRED1 (Sprouty-related protein with an EVH [Ena/Vasp homology] domain 1) and NF1 (neurofibromatosis 1) genes underlie clinically related human disorders. The NF1-encoded protein neurofibromin is a Ras GTPase-activating protein (GAP) and can directly limit Ras activity. Spred proteins also negatively regulate Ras signaling, but the mechanism by which they do so is not clear. In the July 1, 2012, issue of Genes & Development, Stowe and colleagues (pp. 1421-1426) present evidence that Spred1 recruits neurofibromin to the membrane, where it dampens growth factor-induced Ras activity, providing a satisfying explanation for the overlapping features of two human diseases.
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Affiliation(s)
- Andrea I McClatchey
- Massachusetts General Hospital Center for Cancer Research, Department of Pathology, Harvard Medical School, Charlestown, Massachusetts 02129, USA.
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Stowe IB, Mercado EL, Stowe TR, Bell EL, Oses-Prieto JA, Hernández H, Burlingame AL, McCormick F. A shared molecular mechanism underlies the human rasopathies Legius syndrome and Neurofibromatosis-1. Genes Dev 2012; 26:1421-6. [PMID: 22751498 DOI: 10.1101/gad.190876.112] [Citation(s) in RCA: 113] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The Ras/mitogen-activated protein kinase (MAPK) pathway plays a critical role in transducing mitogenic signals from receptor tyrosine kinases. Loss-of-function mutations in one feedback regulator of Ras/MAPK signaling, SPRED1 (Sprouty-related protein with an EVH1 domain), cause Legius syndrome, an autosomal dominant human disorder that resembles Neurofibromatosis-1 (NF1). Spred1 functions as a negative regulator of the Ras/MAPK pathway; however, the underlying molecular mechanism is poorly understood. Here we show that neurofibromin, the NF1 gene product, is a Spred1-interacting protein that is necessary for Spred1's inhibitory function. We show that Spred1 binding induces the plasma membrane localization of NF1, which subsequently down-regulates Ras-GTP levels. This novel mechanism for the regulation of neurofibromin provides a molecular bridge for understanding the overlapping pathophysiology of NF1 and Legius syndrome.
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Affiliation(s)
- Irma B Stowe
- Helen Diller Family Comprehensive Cancer Center, University of California at San Francisco, San Francisco, California 94158, USA
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Han D, Spengler BA, Ross RA. Increased wild-type N-ras activation by neurofibromin down-regulation increases human neuroblastoma stem cell malignancy. Genes Cancer 2012; 2:1034-43. [PMID: 22737269 DOI: 10.1177/1947601912443127] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Accepted: 02/20/2012] [Indexed: 12/30/2022] Open
Abstract
Cellular heterogeneity is a well-known feature of human neuroblastoma tumors and cell lines. Of the 3 phenotypes (N-, I-, and S-type) isolated and characterized, the I-type cancer stem cell of neuroblastoma is the most malignant. Here, we report that, although wild-type N-Ras protein is expressed at the same level in all 3 neuroblastoma cell phenotypes, activated N-Ras-GTP level is significantly higher in I-type cancer stem cells. When activated N-Ras levels were decreased by transfection of a dominant-negative N-Ras construct, the malignant potential of I-type cancer stem cells decreased significantly. Conversely, when weakly malignant N-type cells were transfected with a constitutively active N-Ras construct, activated N-Ras levels, and malignant potential, were significantly increased. Thus, high levels of N-Ras-GTP are required for the increased malignancy of I-type neuroblastoma cancer stem cells. Moreover, increased activation of N-Ras results from significant down-regulation of neurofibromin (NF1), an important RasGAP. This specific down-regulation is mediated by an ubiquitin-proteasome-dependent pathway. Thus, decreased expression of NF1 in I-type neuroblastoma cancer stem cells causes a high level of activated N-Ras that is, at least in part, responsible for their higher tumorigenic potential.
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Affiliation(s)
- Dan Han
- Department of Biological Sciences, Fordham University, Bronx, NY, USA
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Plotkin SR, Bredella MA, Cai W, Kassarjian A, Harris GJ, Esparza S, Merker VL, Munn LL, Muzikansky A, Askenazi M, Nguyen R, Wenzel R, Mautner VF. Quantitative assessment of whole-body tumor burden in adult patients with neurofibromatosis. PLoS One 2012; 7:e35711. [PMID: 22558206 PMCID: PMC3338705 DOI: 10.1371/journal.pone.0035711] [Citation(s) in RCA: 111] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2011] [Accepted: 03/20/2012] [Indexed: 01/29/2023] Open
Abstract
PURPOSE Patients with neurofibromatosis 1 (NF1), NF2, and schwannomatosis are at risk for multiple nerve sheath tumors and premature mortality. Traditional magnetic resonance imaging (MRI) has limited ability to assess disease burden accurately. The aim of this study was to establish an international cohort of patients with quantified whole-body internal tumor burden and to correlate tumor burden with clinical features of disease. METHODS We determined the number, volume, and distribution of internal nerve sheath tumors in patients using whole-body MRI (WBMRI) and three-dimensional computerized volumetry. We quantified the distribution of tumor volume across body regions and used unsupervised cluster analysis to group patients based on tumor distribution. We correlated the presence and volume of internal tumors with disease-related and demographic factors. RESULTS WBMRI identified 1286 tumors in 145/247 patients (59%). Schwannomatosis patients had the highest prevalence of tumors (P = 0.03), but NF1 patients had the highest median tumor volume (P = 0.02). Tumor volume was unevenly distributed across body regions with overrepresentation of the head/neck and pelvis. Risk factors for internal nerve sheath tumors included decreasing numbers of café-au-lait macules in NF1 patients (P = 0.003) and history of skeletal abnormalities in NF2 patients (P = 0.09). Risk factors for higher tumor volume included female gender (P = 0.05) and increasing subcutaneous neurofibromas (P = 0.03) in NF1 patients, absence of cutaneous schwannomas in NF2 patients (P = 0.06), and increasing age in schwannomatosis patients (p = 0.10). CONCLUSION WBMRI provides a comprehensive phenotype of neurofibromatosis patients, identifies distinct anatomic subgroups, and provides the basis for investigating molecular biomarkers that correlate with unique disease manifestations.
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Affiliation(s)
- Scott R Plotkin
- Department of Neurology and Cancer Center, Massachusetts General Hospital, Boston, Massachusetts, United States of America.
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Tumor suppressor functions of FBW7 in cancer development and progression. FEBS Lett 2012; 586:1409-18. [PMID: 22673505 DOI: 10.1016/j.febslet.2012.03.017] [Citation(s) in RCA: 130] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2012] [Revised: 03/09/2012] [Accepted: 03/13/2012] [Indexed: 01/23/2023]
Abstract
FBW7 (F-box and WD repeat domain-containing 7) has been characterized as an onco-suppressor protein in human cancers. Recent studies have also shown that FBW7 exerts its anti-tumor function primarily by promoting the degradation of various oncoproteins, through which FBW7 regulates cellular proliferation, differentiation and causes genetic instability. In this review, we will discuss the role of FBW7 downstream substrates and how dysregulation of Fbw7-mediated proteolysis of these substrates contributes to tumorigenesis. Additionally, we will also summarize the currently available various Fbw7-knockout mouse models that support Fbw7 as a tumor suppressor gene in the development and progression of human malignancies.
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A fraction of neurofibromin interacts with PML bodies in the nucleus of the CCF astrocytoma cell line. Biochem Biophys Res Commun 2012; 418:689-94. [DOI: 10.1016/j.bbrc.2012.01.079] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Accepted: 01/14/2012] [Indexed: 02/07/2023]
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