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Weber SM, Brossier NM, Prechtl A, Barnes S, Wilson LS, Brosius SN, Longo JF, Carroll SL. R-Ras subfamily proteins elicit distinct physiologic effects and phosphoproteome alterations in neurofibromin-null MPNST cells. Cell Commun Signal 2021; 19:95. [PMID: 34530870 PMCID: PMC8447793 DOI: 10.1186/s12964-021-00773-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 07/31/2021] [Indexed: 12/31/2022] Open
Abstract
Background Loss of the Ras GTPase-activating protein neurofibromin promotes nervous system tumor pathogenesis in patients with neurofibromatosis type 1 (NF1). Neurofibromin loss potentially hyperactivates classic Ras (H-Ras, N-Ras, K-Ras), M-Ras, and R-Ras (R-Ras, R-Ras2/TC21) subfamily proteins. We have shown that classic Ras proteins promote proliferation and survival, but not migration, in malignant peripheral nerve sheath tumor (MPNST) cells. However, it is unclear whether R-Ras, R-Ras2 and M-Ras are expressed and hyperactivated in MPNSTs and, if so, whether they contribute to MPNST pathogenesis. We assessed the expression and activation of these proteins in MPNST cells and inhibited them to determine the effect this had on proliferation, migration, invasion, survival and the phosphoproteome. Methods NF1-associated (ST88-14, 90-8, NMS2, NMS-PC, S462, T265-2c) and sporadic (STS-26T, YST-1) MPNST lines were used. Cells were transfected with doxycycline-inducible vectors expressing either a pan-inhibitor of the R-Ras subfamily [dominant negative (DN) R-Ras] or enhanced green fluorescent protein (eGFP). Methodologies used included immunoblotting, immunocytochemistry, PCR, Transwell migration, 3H-thymidine incorporation, calcein cleavage assays and shRNA knockdowns. Proteins in cells with or without DN R-Ras expression were differentially labeled with SILAC and mass spectrometry was used to identify phosphoproteins and determine their relative quantities in the presence and absence of DN R-Ras. Validation of R-Ras and R-Ras2 action and R-Ras regulated networks was performed using genetic and/or pharmacologic approaches. Results R-Ras2 was uniformly expressed in MPNST cells, with R-Ras present in a major subset. Both proteins were activated in neurofibromin-null MPNST cells. Consistent with classical Ras inhibition, DN R-Ras and R-Ras2 knockdown inhibited proliferation. However, DN R-Ras inhibition impaired migration and invasion but not survival. Mass spectrometry-based phosphoproteomics identified thirteen protein networks distinctly regulated by DN R-Ras, including multiple networks regulating cellular movement and morphology. ROCK1 was a prominent mediator in these networks. DN R-Ras expression and RRAS and RRAS2 knockdown inhibited migration and ROCK1 phosphorylation; ROCK1 inhibition similarly impaired migration and invasion, altered cellular morphology and triggered the accumulation of large intracellular vesicles. Conclusions R-Ras proteins function distinctly from classic Ras proteins by regulating distinct signaling pathways that promote MPNST tumorigenesis by mediating migration and invasion. Plain English Summary Mutations of the NF1 gene potentially results in the activation of multiple Ras proteins, which are key regulators of many biologic effects. The protein encoded by the NF1 gene, neurofibromin, acts as an inhibitor of both classic Ras and R-Ras proteins; loss of neurofibromin could cause these Ras proteins to become persistently active, leading to the development of cancer. We have previously shown that three related Ras proteins (the classic Ras proteins) are highly activated in malignant peripheral nerve sheath tumor (MPNST) cells with neurofibromin loss and that they drive cancer cell proliferation and survival by activating multiple cellular signaling pathways. Here, we examined the expression, activation and action of R-Ras proteins in MPNST cells that have lost neurofibromin. Both R-Ras and R-Ras2 are expressed in MPNST cells and activated. Inhibition of R-Ras action inhibited proliferation, migration and invasion but not survival. We examined the activation of cytoplasmic signaling pathways in the presence and absence of R-Ras signaling and found that R-Ras proteins regulated 13 signaling pathways distinct from those regulated by classic Ras proteins. Closer study of an R-Ras regulated pathway containing the signaling protein ROCK1 showed that inhibition of either R-Ras, R-Ras2 or ROCK1 similarly impaired cellular migration and invasion and altered cellular morphology. Inhibition of R-Ras/R-Ras2 and ROCK1 signaling also triggered the accumulation of abnormal intracellular vesicles, indicating that these signaling molecules regulate the movement of proteins and other molecules in the cellular interior. Video Abstract
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Supplementary Information The online version contains supplementary material available at 10.1186/s12964-021-00773-4.
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Affiliation(s)
- Shannon M Weber
- Department of Pathology and Laboratory Medicine (SMW, AP, JFL, SLC), MUSC Medical Scientist Training Program (SMW), Medical University of South Carolina, 171 Ashley Avenue, MSC 908, Charleston, SC, 29425-9080, USA.,Departments of Pathology (NMB, SNB, SLC), Pharmacology and Toxicology (SB, LSW), UAB Medical Scientist Training Program (NMB, SNB), Birmingham, USA.,The University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Nicole M Brossier
- Department of Pathology and Laboratory Medicine (SMW, AP, JFL, SLC), MUSC Medical Scientist Training Program (SMW), Medical University of South Carolina, 171 Ashley Avenue, MSC 908, Charleston, SC, 29425-9080, USA.,Departments of Pathology (NMB, SNB, SLC), Pharmacology and Toxicology (SB, LSW), UAB Medical Scientist Training Program (NMB, SNB), Birmingham, USA.,The University of Alabama at Birmingham, Birmingham, AL, 35294, USA.,Department of Pediatrics, St. Louis Children's Hospital, St. Louis, USA
| | - Amanda Prechtl
- Department of Pathology and Laboratory Medicine (SMW, AP, JFL, SLC), MUSC Medical Scientist Training Program (SMW), Medical University of South Carolina, 171 Ashley Avenue, MSC 908, Charleston, SC, 29425-9080, USA.,Departments of Pathology (NMB, SNB, SLC), Pharmacology and Toxicology (SB, LSW), UAB Medical Scientist Training Program (NMB, SNB), Birmingham, USA.,The University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Stephen Barnes
- Department of Pathology and Laboratory Medicine (SMW, AP, JFL, SLC), MUSC Medical Scientist Training Program (SMW), Medical University of South Carolina, 171 Ashley Avenue, MSC 908, Charleston, SC, 29425-9080, USA.,Departments of Pathology (NMB, SNB, SLC), Pharmacology and Toxicology (SB, LSW), UAB Medical Scientist Training Program (NMB, SNB), Birmingham, USA.,The University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Landon S Wilson
- Department of Pathology and Laboratory Medicine (SMW, AP, JFL, SLC), MUSC Medical Scientist Training Program (SMW), Medical University of South Carolina, 171 Ashley Avenue, MSC 908, Charleston, SC, 29425-9080, USA.,Departments of Pathology (NMB, SNB, SLC), Pharmacology and Toxicology (SB, LSW), UAB Medical Scientist Training Program (NMB, SNB), Birmingham, USA.,The University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Stephanie N Brosius
- Department of Pathology and Laboratory Medicine (SMW, AP, JFL, SLC), MUSC Medical Scientist Training Program (SMW), Medical University of South Carolina, 171 Ashley Avenue, MSC 908, Charleston, SC, 29425-9080, USA.,Departments of Pathology (NMB, SNB, SLC), Pharmacology and Toxicology (SB, LSW), UAB Medical Scientist Training Program (NMB, SNB), Birmingham, USA.,The University of Alabama at Birmingham, Birmingham, AL, 35294, USA.,Departments of Neurology and Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA.,Division of Child Neurology, Children's Hospital of Philadelphia, Philadelphia, USA
| | - Jody Fromm Longo
- Department of Pathology and Laboratory Medicine (SMW, AP, JFL, SLC), MUSC Medical Scientist Training Program (SMW), Medical University of South Carolina, 171 Ashley Avenue, MSC 908, Charleston, SC, 29425-9080, USA.,Departments of Pathology (NMB, SNB, SLC), Pharmacology and Toxicology (SB, LSW), UAB Medical Scientist Training Program (NMB, SNB), Birmingham, USA.,The University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Steven L Carroll
- Department of Pathology and Laboratory Medicine (SMW, AP, JFL, SLC), MUSC Medical Scientist Training Program (SMW), Medical University of South Carolina, 171 Ashley Avenue, MSC 908, Charleston, SC, 29425-9080, USA. .,Departments of Pathology (NMB, SNB, SLC), Pharmacology and Toxicology (SB, LSW), UAB Medical Scientist Training Program (NMB, SNB), Birmingham, USA. .,The University of Alabama at Birmingham, Birmingham, AL, 35294, USA.
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Feroze K, Kaliyadan F. Targeted genetic and molecular therapies in neurofibromatosis - A review of present therapeutic options and a glimpse into the future. Indian J Dermatol Venereol Leprol 2021; 88:1-10. [PMID: 34379966 DOI: 10.25259/ijdvl_6_2020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2020] [Accepted: 05/01/2021] [Indexed: 11/04/2022]
Abstract
Neurofibromatosis type 1, the most common phakomatoses, can present with a host of signs and symptoms, usually involving the skin and the peripheral nervous system. It is characterized by a mutation in the neurofibromatosis type 1 gene on chromosome 17q11.2 that codes for the protein neurofibromin. Neurofibromin acts as a tumor suppressor gene by inhibiting rat sarcoma (Ras) activity and its deficiency leads to increased Ras activity, cellular proliferation and tumor formation. This review was conducted to analyze the various targeted therapies at the genetic and molecular level employed to manage the tumors and other clinical presentations associated with neurofibromatosis type 1. Twenty-eight studies of treatment modalities for the conditions associated with neurofibromatosis and which involved either targeted gene therapy or molecular level therapies, including the latest advances, were included in this review. Mitogen-activated protein kinase kinase inhibition, mammalian target of Rapamycin inhibition and Tyrosine kinase inhibition, represent some of the newer treatment options in this category. Although there are a number of trials for providing therapeutic options at the genetic and molecular level for the various physical and psychological morbidities associated with neurofibromatosis type 1, most of them are in the preclinical stage. Increased clinical trials of the molecules and gene therapies could significantly help in managing the various chronic and sometimes, life-threatening conditions associated with neurofibromatosis 1 and these will probably represent the preferred treatment direction of the future.
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Affiliation(s)
- Kaberi Feroze
- Department of Ophthalmology, Al Azhar Medical College, Thodupuzha, Kerala, India
| | - Feroze Kaliyadan
- Department of Dermatology, College of Medicine, King Faisal University, Hofuf, Saudi Arabia.,Department of Dermatology, Sree Narayana Institute of Medical Sciences, Chalakka, Kerala, India
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Barbet V, Broutier L. Future Match Making: When Pediatric Oncology Meets Organoid Technology. Front Cell Dev Biol 2021; 9:674219. [PMID: 34327198 PMCID: PMC8315550 DOI: 10.3389/fcell.2021.674219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Accepted: 05/10/2021] [Indexed: 11/13/2022] Open
Abstract
Unlike adult cancers that frequently result from the accumulation in time of mutational “hits” often linked to lifestyle, childhood cancers are emerging as diseases of dysregulated development through massive epigenetic alterations. The ability to reconstruct these differences in cancer models is therefore crucial for better understanding the uniqueness of pediatric cancer biology. Cancer organoids (i.e., tumoroids) represent a promising approach for creating patient-derived in vitro cancer models that closely recapitulate the overall pathophysiological features of natural tumorigenesis, including intra-tumoral heterogeneity and plasticity. Though largely applied to adult cancers, this technology is scarcely used for childhood cancers, with a notable delay in technological transfer. However, tumoroids could provide an unprecedented tool to unravel the biology of pediatric cancers and improve their therapeutic management. We herein present the current state-of-the-art of a long awaited and much needed matchmaking.
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Affiliation(s)
- Virginie Barbet
- Childhood Cancer & Cell Death (C3), Université Claude Bernard Lyon 1, INSERM 1052, CNRS 5286, Centre Léon Bérard, Centre de Recherche en Cancérologie de Lyon (CRCL), Lyon, France
| | - Laura Broutier
- Childhood Cancer & Cell Death (C3), Université Claude Bernard Lyon 1, INSERM 1052, CNRS 5286, Centre Léon Bérard, Centre de Recherche en Cancérologie de Lyon (CRCL), Lyon, France
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MiR-27a-3p/miR-27b-3p Promotes Neurofibromatosis Type 1 via Targeting of NF1. J Mol Neurosci 2021; 71:2353-2363. [PMID: 33570696 DOI: 10.1007/s12031-020-01779-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 12/15/2020] [Indexed: 10/22/2022]
Abstract
The dysregulation of microRNAs (miRNAs) is a crucial molecular signature of disease development. The potential implication of miRNAs in neurofibromatosis type 1 (NF1) remains poorly investigated. The expression levels of miR-27a-3p, miR-27b-3p, and neurofibromin 1 (NF1) were detected by real-time quantitative polymerase chain reaction (RT-qPCR) analysis. The functional roles of miR-27a-3p and miR-27b-3p in NF1 were explored by CCK8 (Cell Counting Kit-8), 5-ethynyl-2'-deoxyuridine (EdU), terminal deoxynucleoitidyl transferase dUTP nick-end labeling (TUNEL), and transwell assays. Luciferase reporter, RNA pull-down, and RNA binding protein immunoprecipitation (RIP) assays were employed to study the probable target relationship between miRNA and messenger RNA (mRNA). MiR-27b-3p and miR-27a-3p were upregulated in dermal and plexiform human Schwann cells (HSC) from NF1 neurofibromas as well as cell lines of malignant peripheral nerve sheath tumors (MPNSTs). MiR-27a-3p/miR-27b-3p mimics promoted the proliferative, migratory, and invasive ability of dermal HSC and MPNST cell ST88-14, while inhibiting the apoptotic capacity. MiR-27a-3p/miR-27b-3p inhibitors elicited the opposite impacts on the above cellular behaviors in dermal HSC and ST88-14. Intriguingly, NF1 was revealed to be the target of both miR-27a-3p and miR-27b-3p, and was negatively modulated by them. MiR-27a-3p/miR-27b-3p upregulation suppressed the expression of NF1 in dermal HSC and ST88-14. Furthermore, NF1 depletion counterbalanced the functional alteration induced by miR-27a-3p/miR-27b-3p inhibition. Our study suggests that both miR-27b-3p and miR-27a-3p are involved in upstream molecular activity responsible for the depletion of NF1, representing promising targets for therapeutic application in NF1.
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Abstract
Ras proteins mediate extracellular and cytoplasmic signaling networks via receptor tyrosine kinase. The Ras pathway induces activation of signaling molecules involved in cell proliferation and growth, cell survival and apoptosis, metabolism, and motility. Although Ras mutations in breast cancer are not frequently reported, hyperactivation of Ras signaling plays an important role in breast cancer growth and progression. Oncogenic Ras activation occurs via loss of Ras GTPase-activating proteins, overexpression of growth factor receptor, and stimulation by various cytokines. Effective control of oncogenic Ras is one of the therapeutic strategies in breast cancer. The mechanisms of intracellular localization, activation, and signaling pathway of Ras in cancer have been used to develop therapeutic candidates. Recent studies have reported an effective therapy for breast cancer by inhibition of enzymes involved in the posttranslational modification of Ras, such as farnesyltransferase and geranylgeranyltransferase 1, and anti-cancer therapies targeting the epidermal growth factor receptor (EGFR). Emerging targets involved in EGF-mediated Ras activity in breast cancer have shed new insight into Ras activation in breast cancer progression. These alternative mechanisms for Ras signaling pathway may suggest novel therapeutic approaches for targeting Ras in breast cancer. In spite of the difficulties in targeting Ras protein, important discoveries highlight the direct inhibition of Ras activity. Further studies may elucidate the effects of targeting Ras protein and the clinical relevance thereof.
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Tao J, Sun D, Dong L, Zhu H, Hou H. Advancement in research and therapy of NF1 mutant malignant tumors. Cancer Cell Int 2020; 20:492. [PMID: 33061844 PMCID: PMC7547409 DOI: 10.1186/s12935-020-01570-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 09/23/2020] [Indexed: 12/27/2022] Open
Abstract
The NF1 gene encodes neurofibromin, which is one of the primary negative regulatory factors of the Ras protein. Neurofibromin stimulates the GTPase activity of Ras to convert it from an active GTP-bound form to its inactive GDP-bound form through its GTPase activating protein-related domain (GRD). Therefore, neurofibromin serves as a shutdown signal for all vertebrate RAS GTPases. NF1 mutations cause a resultant decrease in neurofibromin expression, which has been detected in many human malignancies, including NSCLC, breast cancer and so on. NF1 mutations are associated with the underlying mechanisms of treatment resistance discovered in multiple malignancies. This paper reviews the possible mechanisms of NF1 mutation-induced therapeutic resistance to chemotherapy, endocrine therapy and targeted therapy in malignancies. Then, we further discuss advancements in targeted therapy for NF1-mutated malignant tumors. In addition, therapies targeting the downstream molecules of NF1 might be potential novel strategies for the treatment of advanced malignancies.
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Affiliation(s)
- Junyan Tao
- Precision Medicine Center of Oncology, the Affiliated Hospital of Qingdao University, No. 59 Haier Road, Qingdao, Shandong 266000 China
| | - Dantong Sun
- Precision Medicine Center of Oncology, the Affiliated Hospital of Qingdao University, No. 59 Haier Road, Qingdao, Shandong 266000 China
| | - Lina Dong
- Precision Medicine Center of Oncology, the Affiliated Hospital of Qingdao University, No. 59 Haier Road, Qingdao, Shandong 266000 China
| | - Hua Zhu
- Precision Medicine Center of Oncology, the Affiliated Hospital of Qingdao University, No. 59 Haier Road, Qingdao, Shandong 266000 China
| | - Helei Hou
- Precision Medicine Center of Oncology, the Affiliated Hospital of Qingdao University, No. 59 Haier Road, Qingdao, Shandong 266000 China
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7
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Chang LS, Oblinger JL, Burns SS, Huang J, Anderson LW, Hollingshead MG, Shen R, Pan L, Agarwal G, Ren Y, Roberts RD, O'Keefe BR, Kinghorn AD, Collins JM. Targeting Protein Translation by Rocaglamide and Didesmethylrocaglamide to Treat MPNST and Other Sarcomas. Mol Cancer Ther 2020; 19:731-741. [PMID: 31848295 PMCID: PMC7056570 DOI: 10.1158/1535-7163.mct-19-0809] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 12/02/2019] [Accepted: 12/13/2019] [Indexed: 01/30/2023]
Abstract
Malignant peripheral nerve sheath tumors (MPNST) frequently overexpress eukaryotic initiation factor 4F components, and the eIF4A inhibitor silvestrol potently suppresses MPNST growth. However, silvestrol has suboptimal drug-like properties, including a bulky structure, poor oral bioavailability (<2%), sensitivity to MDR1 efflux, and pulmonary toxicity in dogs. We compared ten silvestrol-related rocaglates lacking the dioxanyl ring and found that didesmethylrocaglamide (DDR) and rocaglamide (Roc) had growth-inhibitory activity comparable with silvestrol. Structure-activity relationship analysis revealed that the dioxanyl ring present in silvestrol was dispensable for, but may enhance, cytotoxicity. Both DDR and Roc arrested MPNST cells at G2-M, increased the sub-G1 population, induced cleavage of caspases and PARP, and elevated the levels of the DNA-damage response marker γH2A.X, while decreasing the expression of AKT and ERK1/2, consistent with translation inhibition. Unlike silvestrol, DDR and Roc were not sensitive to MDR1 inhibition. Pharmacokinetic analysis confirmed that Roc had 50% oral bioavailability. Importantly, Roc, when administered intraperitoneally or orally, showed potent antitumor effects in an orthotopic MPNST mouse model and did not induce pulmonary toxicity in dogs as found with silvestrol. Treated tumors displayed degenerative changes and had more cleaved caspase-3-positive cells, indicative of increased apoptosis. Furthermore, Roc effectively suppressed the growth of osteosarcoma, Ewing sarcoma, and rhabdomyosarcoma cells and patient-derived xenografts. Both Roc- and DDR-treated sarcoma cells showed decreased levels of multiple oncogenic kinases, including insulin-like growth factor-1 receptor. The more favorable drug-like properties of DDR and Roc and the potent antitumor activity of Roc suggest that these rocaglamides could become viable treatments for MPNST and other sarcomas.
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Affiliation(s)
- Long-Sheng Chang
- Center for Childhood Cancer and Blood Diseases, Abigail Wexner Research Institute, Nationwide Children's Hospital, Columbus, Ohio.
- Department of Pediatrics, The Ohio State University College of Medicine, Columbus, Ohio
- Department of Otolaryngology-Head and Neck Surgery, The Ohio State University College of Medicine, Columbus, Ohio
- Department of Pathology, The Ohio State University College of Medicine, Columbus, Ohio
| | - Janet L Oblinger
- Center for Childhood Cancer and Blood Diseases, Abigail Wexner Research Institute, Nationwide Children's Hospital, Columbus, Ohio
- Department of Pediatrics, The Ohio State University College of Medicine, Columbus, Ohio
| | - Sarah S Burns
- Center for Childhood Cancer and Blood Diseases, Abigail Wexner Research Institute, Nationwide Children's Hospital, Columbus, Ohio
- Department of Pediatrics, The Ohio State University College of Medicine, Columbus, Ohio
| | - Jie Huang
- Center for Childhood Cancer and Blood Diseases, Abigail Wexner Research Institute, Nationwide Children's Hospital, Columbus, Ohio
- Department of Pediatrics, The Ohio State University College of Medicine, Columbus, Ohio
| | - Larry W Anderson
- Division of Cancer Treatment and Diagnosis, Center for Cancer Research, National Cancer Institute, NIH, Frederick, Maryland
| | - Melinda G Hollingshead
- Division of Cancer Treatment and Diagnosis, Center for Cancer Research, National Cancer Institute, NIH, Frederick, Maryland
| | - Rulong Shen
- Department of Pathology, The Ohio State University College of Medicine, Columbus, Ohio
| | - Li Pan
- Division of Medicinal Chemistry and Pharmacognosy, The Ohio State University College of Pharmacy, Columbus, Ohio
| | - Garima Agarwal
- Division of Medicinal Chemistry and Pharmacognosy, The Ohio State University College of Pharmacy, Columbus, Ohio
| | - Yulin Ren
- Division of Medicinal Chemistry and Pharmacognosy, The Ohio State University College of Pharmacy, Columbus, Ohio
| | - Ryan D Roberts
- Center for Childhood Cancer and Blood Diseases, Abigail Wexner Research Institute, Nationwide Children's Hospital, Columbus, Ohio
- Department of Pediatrics, The Ohio State University College of Medicine, Columbus, Ohio
| | - Barry R O'Keefe
- Division of Cancer Treatment and Diagnosis, Center for Cancer Research, National Cancer Institute, NIH, Frederick, Maryland
- Molecular Targets Program, Center for Cancer Research, National Cancer Institute, NIH, Frederick, Maryland
| | - A Douglas Kinghorn
- Division of Medicinal Chemistry and Pharmacognosy, The Ohio State University College of Pharmacy, Columbus, Ohio
| | - Jerry M Collins
- Division of Cancer Treatment and Diagnosis, Center for Cancer Research, National Cancer Institute, NIH, Frederick, Maryland
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Abstract
Cancer is a cumulative manifestation of several complicated disease states that affect multiple organs. Over the last few decades, the fruit fly Drosophila melanogaster, has become a successful model for studying human cancers. The genetic simplicity and vast arsenal of genetic tools available in Drosophila provides a unique opportunity to address questions regarding cancer initiation and progression that would be extremely challenging in other model systems. In this chapter we provide a historical overview of Drosophila as a model organism for cancer research, summarize the multitude of genetic tools available, offer a brief comparison between different model organisms and cell culture platforms used in cancer studies and briefly discuss some of the latest models and concepts in recent Drosophila cancer research.
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Patwardhan PP, Musi E, Schwartz GK. Preclinical Evaluation of Nintedanib, a Triple Angiokinase Inhibitor, in Soft-tissue Sarcoma: Potential Therapeutic Implication for Synovial Sarcoma. Mol Cancer Ther 2018; 17:2329-2340. [PMID: 30166401 DOI: 10.1158/1535-7163.mct-18-0319] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 07/25/2018] [Accepted: 08/21/2018] [Indexed: 11/16/2022]
Abstract
Sarcomas are rare cancers that make up about 1% of all cancers in adults; however, they occur more commonly among children and young adolescents. Sarcomas are genetically complex and are often difficult to treat given the lack of clinical efficacy of any of the currently available therapies. Receptor tyrosine kinases (RTK) such as c-Kit, c-Met, PDGFR, IGF-1R, as well as FGFR have all been reported to be involved in driving tumor development and progression in adult and pediatric soft-tissue sarcoma. These driver kinases often act as critical determinants of tumor cell proliferation and targeting these signal transduction pathways remains an attractive therapeutic approach. Nintedanib, a potent triple angiokinase inhibitor, targets PDGFR, VEGFR, and FGFR pathways critical for tumor angiogenesis and vasculature. In this study, we evaluated the preclinical efficacy of nintedanib in soft-tissue sarcoma cell lines. Nintedanib treatment resulted in significant antiproliferative effect in vitro in cell lines with high expression of RTK drug targets. Furthermore, treatment with nintedanib showed significant downregulation of downstream phosphorylated AKT and ERK1/2. Finally, treatment with nintedanib resulted in significant tumor growth suppression in mouse xenograft model of synovial sarcoma. Notably, both the in vitro and in vivo efficacy of nintedanib was superior to that of imatinib, another multikinase inhibitor, previously tested with minimal success in clinical trials in sarcoma. Overall, the data from this study provide a strong rationale to warrant further clinical exploration of this drug in patients with synovial sarcoma. Mol Cancer Ther; 17(11); 2329-40. ©2018 AACR.
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Affiliation(s)
- Parag P Patwardhan
- Department of Medicine, Columbia University Medical Center, New York, New York.
| | - Elgilda Musi
- Department of Medicine, Columbia University Medical Center, New York, New York
| | - Gary K Schwartz
- Department of Medicine, Columbia University Medical Center, New York, New York.,Herbert Irving Comprehensive Cancer Center, Columbia University College of Medicine, New York, New York
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Varin J, Poulain L, Hivelin M, Nusbaum P, Hubas A, Laurendeau I, Lantieri L, Wolkenstein P, Vidaud M, Pasmant E, Chapuis N, Parfait B. Dual mTORC1/2 inhibition induces anti-proliferative effect in NF1-associated plexiform neurofibroma and malignant peripheral nerve sheath tumor cells. Oncotarget 2018; 7:35753-35767. [PMID: 26840085 PMCID: PMC5094959 DOI: 10.18632/oncotarget.7099] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 01/19/2016] [Indexed: 01/23/2023] Open
Abstract
Approximately 30-50% of individuals with Neurofibromatosis type 1 develop benign peripheral nerve sheath tumors, called plexiform neurofibromas (PNFs). PNFs can undergo malignant transformation to highly metastatic malignant peripheral nerve sheath tumors (MPNSTs) in 5-10% of NF1 patients, with poor prognosis. No effective systemic therapy is currently available for unresectable tumors. In tumors, the NF1 gene deficiency leads to Ras hyperactivation causing the subsequent activation of the AKT/mTOR and Raf/MEK/ERK pathways and inducing multiple cellular responses including cell proliferation. In this study, three NF1-null MPNST-derived cell lines (90-8, 88-14 and 96-2), STS26T sporadic MPNST cell line and PNF-derived primary Schwann cells were used to test responses to AZD8055, an ATP-competitive “active-site” mTOR inhibitor. In contrast to rapamycin treatment which only partially affected mTORC1 signaling, AZD8055 induced a strong inhibition of mTORC1 and mTORC2 signaling in MPNST-derived cell lines and PNF-derived Schwann cells. AZD8055 induced full blockade of mTORC1 leading to an efficient decrease of global protein synthesis. A higher cytotoxic effect was observed with AZD8055 compared to rapamycin in the NF1-null MPNST-derived cell lines with IC50 ranging from 70 to 140 nM and antiproliferative effect was confirmed in PNF-derived Schwann cells. Cell migration was impaired by AZD8055 treatment and cell cycle analysis showed a G0/G1 arrest. Combined effects of AZD8055 and PD0325901 MEK inhibitor as well as BRD4 (BromoDomain-containing protein 4) inhibitors showed a synergistic antiproliferative effect. These data suggest that NF1-associated peripheral nerve sheath tumors are an ideal target for AZD8055 as a single molecule or in combined therapies.
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Affiliation(s)
- Jennifer Varin
- EA7331, Faculté de Pharmacie de Paris, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Laury Poulain
- Institut Cochin, Département d'Immuno-Hématologie, CNRS UMR8104, INSERM U1016, Paris, France
| | - Mikael Hivelin
- Service de Chirurgie Plastique et Reconstructrice, Hôpital Européen Georges Pompidou- AP-HP, Université Paris Descartes, Paris, France
| | - Patrick Nusbaum
- Service de Biochimie et de Génétique Moléculaire, Hôpital Cochin, AP-HP, Paris, France
| | - Arnaud Hubas
- Service de Biochimie et de Génétique Moléculaire, Hôpital Cochin, AP-HP, Paris, France
| | - Ingrid Laurendeau
- EA7331, Faculté de Pharmacie de Paris, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Laurent Lantieri
- Service de Chirurgie Plastique et Reconstructrice, Hôpital Européen Georges Pompidou- AP-HP, Université Paris Descartes, Paris, France
| | - Pierre Wolkenstein
- Département de Dermatologie, Centre de Référence des Neurofibromatoses, Hôpital Henri-Mondor, AP-HP , Créteil, France.,EA 4393 LIC, Université Paris Est Créteil (UPEC), Créteil, France
| | - Michel Vidaud
- EA7331, Faculté de Pharmacie de Paris, Université Paris Descartes, Sorbonne Paris Cité, Paris, France.,Service de Biochimie et de Génétique Moléculaire, Hôpital Cochin, AP-HP, Paris, France
| | - Eric Pasmant
- EA7331, Faculté de Pharmacie de Paris, Université Paris Descartes, Sorbonne Paris Cité, Paris, France.,Service de Biochimie et de Génétique Moléculaire, Hôpital Cochin, AP-HP, Paris, France
| | - Nicolas Chapuis
- Institut Cochin, Département d'Immuno-Hématologie, CNRS UMR8104, INSERM U1016, Paris, France.,Service d'Hématologie Biologique, Hôpital Cochin, AP-HP, Paris, France
| | - Béatrice Parfait
- EA7331, Faculté de Pharmacie de Paris, Université Paris Descartes, Sorbonne Paris Cité, Paris, France.,Service de Biochimie et de Génétique Moléculaire, Hôpital Cochin, AP-HP, Paris, France
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11
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Masgras I, Ciscato F, Brunati AM, Tibaldi E, Indraccolo S, Curtarello M, Chiara F, Cannino G, Papaleo E, Lambrughi M, Guzzo G, Gambalunga A, Pizzi M, Guzzardo V, Rugge M, Vuljan SE, Calabrese F, Bernardi P, Rasola A. Absence of Neurofibromin Induces an Oncogenic Metabolic Switch via Mitochondrial ERK-Mediated Phosphorylation of the Chaperone TRAP1. Cell Rep 2017; 18:659-672. [PMID: 28099845 DOI: 10.1016/j.celrep.2016.12.056] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 11/04/2016] [Accepted: 12/18/2016] [Indexed: 01/21/2023] Open
Abstract
Mutations in neurofibromin, a Ras GTPase-activating protein, lead to the tumor predisposition syndrome neurofibromatosis type 1. Here, we report that cells lacking neurofibromin exhibit enhanced glycolysis and decreased respiration in a Ras/ERK-dependent way. In the mitochondrial matrix of neurofibromin-deficient cells, a fraction of active ERK1/2 associates with succinate dehydrogenase (SDH) and TRAP1, a chaperone that promotes the accumulation of the oncometabolite succinate by inhibiting SDH. ERK1/2 enhances both formation of this multimeric complex and SDH inhibition. ERK1/2 kinase activity is favored by the interaction with TRAP1, and TRAP1 is, in turn, phosphorylated in an ERK1/2-dependent way. TRAP1 silencing or mutagenesis at the serine residues targeted by ERK1/2 abrogates tumorigenicity, a phenotype that is reverted by addition of a cell-permeable succinate analog. Our findings reveal that Ras/ERK signaling controls the metabolic changes orchestrated by TRAP1 that have a key role in tumor growth and are a promising target for anti-neoplastic strategies.
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Affiliation(s)
- Ionica Masgras
- CNR Institute of Neuroscience and Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
| | - Francesco Ciscato
- CNR Institute of Neuroscience and Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
| | - Anna Maria Brunati
- Department of Molecular Medicine, University of Padova, 35131 Padova, Italy
| | - Elena Tibaldi
- Department of Molecular Medicine, University of Padova, 35131 Padova, Italy
| | | | | | - Federica Chiara
- Department of Cardiac, Thoracic, and Vascular Sciences, University of Padova, 35128 Padova, Italy
| | - Giuseppe Cannino
- CNR Institute of Neuroscience and Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
| | - Elena Papaleo
- Computational Biology Laboratory, Unit of Statistics, Bioinformatics and Registry, Danish Cancer Society Research Center, 2100 Copenhagen, Denmark
| | - Matteo Lambrughi
- Computational Biology Laboratory, Unit of Statistics, Bioinformatics and Registry, Danish Cancer Society Research Center, 2100 Copenhagen, Denmark
| | - Giulia Guzzo
- CNR Institute of Neuroscience and Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
| | - Alberto Gambalunga
- Department of Cardiac, Thoracic, and Vascular Sciences, University of Padova, 35128 Padova, Italy
| | - Marco Pizzi
- Department of Medicine, University of Padova, 35128 Padova, Italy
| | | | - Massimo Rugge
- Department of Medicine, University of Padova, 35128 Padova, Italy
| | - Stefania Edith Vuljan
- Department of Cardiac, Thoracic, and Vascular Sciences, University of Padova, 35128 Padova, Italy
| | - Fiorella Calabrese
- Department of Cardiac, Thoracic, and Vascular Sciences, University of Padova, 35128 Padova, Italy
| | - Paolo Bernardi
- CNR Institute of Neuroscience and Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
| | - Andrea Rasola
- CNR Institute of Neuroscience and Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy.
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12
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Sheikh TN, Patwardhan PP, Cremers S, Schwartz GK. Targeted inhibition of glutaminase as a potential new approach for the treatment of NF1 associated soft tissue malignancies. Oncotarget 2017; 8:94054-94068. [PMID: 29212209 PMCID: PMC5706855 DOI: 10.18632/oncotarget.21573] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Accepted: 09/16/2017] [Indexed: 01/23/2023] Open
Abstract
Many cancer cells rely on glutamine as the source of carbon molecules to feed the biosynthetic pathways and are often addicted to glutaminolysis. Inhibitors of glutaminase activity have gained attention in the last few years due to their anti-proliferative effect and ability to induce apoptosis in some cancers. Although it is a promising therapeutic approach, its efficacy or the role played by glutamine in modulating cell proliferation in NF1 associated tumors has never been studied. We report for the first time, a strong correlation between the NF1 status of tumor cells and increased sensitivity to glutamine deprivation and glutaminase inhibition. Soft-tissue cell lines null for NF1 were highly dependent on glutamine for proliferation and showed decreased mTORC1 and Ras activity in response to glutaminase inhibition. Re-addition of glutamine or intermediary metabolite such as glutamate to the media restored mTORC1 and Ras activity. SiRNA mediated NF1 knockdown in wild-type NF1 cell line shows increased sensitivity to glutaminase inhibition. Conversely, NF1 overexpression in NF1 null cell lines results in reduced sensitivity to glutaminase inhibition, and restores mTORC1 signaling and Ras activity. These findings provide new insights into the role played by glutamine metabolism in NF1 associated tumors and strongly warrant further investigation as a potential therapy in the NF1 disease setting.
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Affiliation(s)
- Tahir N Sheikh
- Herbert Irving Comprehensive Cancer Center, New York, NY, USA
| | | | - Serge Cremers
- Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Gary K Schwartz
- Herbert Irving Comprehensive Cancer Center, New York, NY, USA.,Department of Hematology/Oncology, Columbia University College of Medicine, New York, NY, USA
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13
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Kim A, Pratilas CA. The promise of signal transduction in genetically driven sarcomas of the nerve. Exp Neurol 2017; 299:317-325. [PMID: 28859862 DOI: 10.1016/j.expneurol.2017.08.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 08/24/2017] [Accepted: 08/25/2017] [Indexed: 12/28/2022]
Abstract
Neurofibromatosis type 1 (NF1) is an autosomal dominant tumor predisposition syndrome. Malignant peripheral nerve sheath tumors (MPNST) are aggressive soft tissue sarcomas arising from peripheral nerve sheaths, and the most commonly lethal feature associated with NF1. The hallmark of NF1 and NF1-related MPNST is the loss of neurofibromin expression. Loss of neurofibromin is considered a tumor-promoting event, and leads to constitutive activation of RAS and its downstream effectors. However, RAS activation alone is not sufficient for MPNST formation, and additional tumor suppressors and signaling pathways have been implicated in tumorigenesis of MPNST. Taking advantage of the rapid development of novel therapeutics targeting key molecular pathways across all cancer types, the best-in-class modulators of these pathways can be assessed in pre-clinical models and translated into clinical trials for patients with MPNST. Here, we describe the genetic changes and molecular pathways that drive MPNST formation and highlight the promise of signal transduction to identify therapies that may treat these tumors more effectively.
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Affiliation(s)
- AeRang Kim
- Children's National Medical Center, Washington, D.C., United States
| | - Christine A Pratilas
- Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, MD, United States.
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14
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Sekerdag E, Lüle S, Bozdağ Pehlivan S, Öztürk N, Kara A, Kaffashi A, Vural I, Işıkay I, Yavuz B, Oguz KK, Söylemezoğlu F, Gürsoy-Özdemir Y, Mut M. A potential non-invasive glioblastoma treatment: Nose-to-brain delivery of farnesylthiosalicylic acid incorporated hybrid nanoparticles. J Control Release 2017; 261:187-198. [PMID: 28684169 DOI: 10.1016/j.jconrel.2017.06.032] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 05/29/2017] [Accepted: 06/28/2017] [Indexed: 11/26/2022]
Abstract
New drug delivery systems are highly needed in research and clinical area to effectively treat gliomas by reaching a high antineoplastic drug concentration at the target site without damaging healthy tissues. Intranasal (IN) administration, an alternative route for non-invasive drug delivery to the brain, bypasses the blood-brain-barrier (BBB) and eliminates systemic side effects. This study evaluated the antitumor efficacy of farnesylthiosalicylic acid (FTA) loaded (lipid-cationic) lipid-PEG-PLGA hybrid nanoparticles (HNPs) after IN application in rats. FTA loaded HNPs were prepared, characterized and evaluated for cytotoxicity. Rat glioma 2 (RG2) cells were implanted unilaterally into the right striatum of female Wistar rats. 10days later, glioma bearing rats received either no treatment, or 5 repeated doses of 500μM freshly prepared FTA loaded HNPs via IN or intravenous (IV) application. Pre-treatment and post-treatment tumor sizes were determined with MRI. After a treatment period of 5days, IN applied FTA loaded HNPs achieved a significant decrease of 55.7% in tumor area, equal to IV applied FTA loaded HNPs. Herewith, we showed the potential utility of IN application of FTA loaded HNPs as a non-invasive approach in glioblastoma treatment.
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Affiliation(s)
- Emine Sekerdag
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Hacettepe University, Ankara, Turkey; Neuroscience Research Lab, Research Center for Translational Medicine, Koҫ University, Istanbul, Turkey.
| | - Sevda Lüle
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey; Neuroscience Center and Department of Pediatrics, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Sibel Bozdağ Pehlivan
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Hacettepe University, Ankara, Turkey
| | - Naile Öztürk
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Hacettepe University, Ankara, Turkey
| | - Aslı Kara
- Department of Nanotechnology and Nanomedicine, Faculty of Pharmacy, Hacettepe University, Ankara, Turkey; Department of Biology, Faculty of Art and Science, Hitit University, Çorum, Turkey
| | - Abbas Kaffashi
- Department of Nanotechnology and Nanomedicine, Faculty of Pharmacy, Hacettepe University, Ankara, Turkey
| | - Imran Vural
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Hacettepe University, Ankara, Turkey
| | - Ilkay Işıkay
- Department of Neurosurgery, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Burҫin Yavuz
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Hacettepe University, Ankara, Turkey
| | - Kader Karlı Oguz
- Department of Radiology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Figen Söylemezoğlu
- Department of Pathology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Yasemin Gürsoy-Özdemir
- Neuroscience Research Lab, Research Center for Translational Medicine, Koҫ University, Istanbul, Turkey; Department of Neurology, School of Medicine, Koҫ University, Istanbul, Turkey
| | - Melike Mut
- Department of Neurosurgery, Faculty of Medicine, Hacettepe University, Ankara, Turkey
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15
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Malignant Peripheral Nerve Sheath Tumors State of the Science: Leveraging Clinical and Biological Insights into Effective Therapies. Sarcoma 2017; 2017:7429697. [PMID: 28592921 PMCID: PMC5448069 DOI: 10.1155/2017/7429697] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Accepted: 04/03/2017] [Indexed: 01/08/2023] Open
Abstract
Malignant peripheral nerve sheath tumor (MPNST) is the leading cause of mortality in patients with neurofibromatosis type 1. In 2002, an MPNST consensus statement reviewed the current knowledge and provided guidance for the diagnosis and management of MPNST. Although the improvement in clinical outcome has not changed, substantial progress has been made in understanding the natural history and biology of MPNST through imaging and genomic advances since 2002. Genetically engineered mouse models that develop MPNST spontaneously have greatly facilitated preclinical evaluation of novel drugs for translation into clinical trials led by consortia efforts. Continued work in identifying alterations that contribute to the transformation, progression, and metastasis of MPNST coupled with longitudinal follow-up, biobanking, and data sharing is needed to develop prognostic biomarkers and effective prevention and therapeutic strategies for MPNST.
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16
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Malignant Peripheral Nerve Sheath Tumors. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 916:495-530. [DOI: 10.1007/978-3-319-30654-4_22] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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17
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McCarthy M, Prakash P, Gorfe AA. Computational allosteric ligand binding site identification on Ras proteins. Acta Biochim Biophys Sin (Shanghai) 2016; 48:3-10. [PMID: 26487442 DOI: 10.1093/abbs/gmv100] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 08/16/2015] [Indexed: 12/19/2022] Open
Abstract
A number of computational techniques have been proposed to expedite the process of allosteric ligand binding site identification in inherently flexible and hence challenging drug targets. Some of these techniques have been instrumental in the discovery of allosteric ligand binding sites on Ras proteins, a group of elusive anticancer drug targets. This review provides an overview of these techniques and their application to Ras proteins. A summary of molecular docking and binding site identification is provided first, followed by a more detailed discussion of two specific techniques for binding site identification in ensembles of Ras conformations generated by molecular simulations.
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Affiliation(s)
- Michael McCarthy
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Priyanka Prakash
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Alemayehu A Gorfe
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
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18
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Abstract
Neurofibromatosis type 1 (NF1) is a relatively common tumour predisposition syndrome related to germline aberrations of NF1, a tumour suppressor gene. The gene product neurofibromin is a negative regulator of the Ras cellular proliferation pathway, and also exerts tumour suppression via other mechanisms. Recent next-generation sequencing projects have revealed somatic NF1 aberrations in various sporadic tumours. NF1 plays a critical role in a wide range of tumours. NF1 alterations appear to be associated with resistance to therapy and adverse outcomes in several tumour types. Identification of a patient's germline or somatic NF1 aberrations can be challenging, as NF1 is one of the largest human genes, with a myriad of possible mutations. Epigenetic factors may also contribute to inadequate levels of neurofibromin in cancer cells. Clinical trials of NF1-based therapeutic approaches are currently limited. Preclinical studies on neurofibromin-deficient malignancies have mainly been on malignant peripheral nerve sheath tumour cell lines or xenografts derived from NF1 patients. However, the emerging recognition of the role of NF1 in sporadic cancers may lead to the development of NF1-based treatments for other tumour types. Improved understanding of the implications of NF1 aberrations is critical for the development of novel therapeutic strategies.
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19
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Classic Ras Proteins Promote Proliferation and Survival via Distinct Phosphoproteome Alterations in Neurofibromin-Null Malignant Peripheral Nerve Sheath Tumor Cells. J Neuropathol Exp Neurol 2015; 74:568-86. [PMID: 25946318 DOI: 10.1097/nen.0000000000000201] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Neurofibromin, the tumor suppressor encoded by the neurofibromatosis type 1 (NF1) gene, potentially suppresses the activation of H-Ras, N-Ras, and K-Ras. However, it is not known whether these classic Ras proteins are hyperactivated in NF1-null nerve sheath tumors, how they contribute to tumorigenesis, and what signaling pathways mediate their effects. Here we show that H-Ras, N-Ras, and K-Ras are coexpressed with their activators (guanine nucleotide exchange factors) in neurofibromin-null malignant peripheral nerve sheath tumor (MPNST) cells, and that all 3 Ras proteins are activated. Dominant negative (DN) H-Ras, a pan-inhibitor of the classic Ras family, inhibited MPNST proliferation and survival, but not migration. However, NF1-null MPNST cells were variably dependent on individual Ras proteins. In some lines, ablation of H-Ras, N-Ras, and/or K-Ras inhibited mitogenesis. In others, ablation of a single Ras protein had no effect on proliferation; in these lines, ablation of a single Ras protein resulted in compensatory increases in the activation and/or expression of other Ras proteins. Using mass spectrometry-based phosphoproteomics, we identified 7 signaling networks affecting morphology, proliferation, and survival that are regulated by DN H-Ras. Thus, neurofibromin loss activates multiple classic Ras proteins that promote proliferation and survival by regulating several distinct signaling cascades.
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20
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Zhang Y, Huang Y, Li S. Polymeric micelles: nanocarriers for cancer-targeted drug delivery. AAPS PharmSciTech 2014; 15:862-71. [PMID: 24700296 DOI: 10.1208/s12249-014-0113-z] [Citation(s) in RCA: 198] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Accepted: 03/13/2014] [Indexed: 11/30/2022] Open
Abstract
Polymeric micelles represent an effective delivery system for poorly water-soluble anticancer drugs. With small size (10-100 nm) and hydrophilic shell of PEG, polymeric micelles exhibit prolonged circulation time in the blood and enhanced tumor accumulation. In this review, the importance of rational design was highlighted by summarizing the recent progress on the development of micellar formulations. Emphasis is placed on the new strategies to enhance the drug/carrier interaction for improved drug-loading capacity. In addition, the micelle-forming drug-polymer conjugates are also discussed which have both drug-loading function and antitumor activity.
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21
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Affiliation(s)
- Roni Rak
- Department of Neurobiology; The George S. Wise Faculty of Life Sciences; Tel Aviv University; Tel Aviv, Israel
| | - Yoel Kloog
- Department of Neurobiology; The George S. Wise Faculty of Life Sciences; Tel Aviv University; Tel Aviv, Israel
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22
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Abstract
Galectins are a family of β-galactoside-binding lectins that exert diverse extracellular and intracellular effects. Galectin-7 and galectin-1 show opposing effects on proliferation and survival in different cell types. Galectin-7 is a p53-induced gene and an enhancer of apoptosis, whereas galectin-1 induces tumorigenicity and resistance to apoptosis in several types of cancers. We show here that in cells derived from neurofibromin-deficient (Nf1−/−) malignant peripheral nerve sheath tumors (MPNSTs), Ras inhibition by S-trans,trans-farnesylthiosalicylic-acid (FTS; Salirasib) shifts the pattern of galectin expression. Whereas FTS decreased levels of both active Ras and galectin-1 expression, it dramatically increased both the mRNA and protein expression levels of galectin-7. Galectin-7 accumulation was mediated through JNK inhibition presumably resulting from the observed induction of p53, and was negatively regulated by the AP-1 inhibitor JDP2. Expression of galectin-7 by itself decreased Ras activation in ST88-14 cells and rendered them sensitive to apoptosis. This observed shift in galectin expression pattern together with the accompanying shift from cell proliferation to apoptosis represents a novel pattern of Ras inhibition by FTS. This seems likely to be an important phenomenon in view of the fact that both enhanced cell proliferation and defects of apoptosis constitute major hallmarks of human cancers and play a central role in the resistance of MPNSTs to anti-cancer treatments. These findings suggest that FTS, alone or in combination with chemotherapy agents, may be worth developing as a possible treatment for MPNSTs.
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23
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Abstract
The Ras inhibitor S-trans,trans-farnesylthiosalicylic acid (FTS, Salirasib®) interferes with Ras membrane interactions that are crucial for Ras-dependent signaling and cellular transformation. FTS had been successfully evaluated in clinical trials of cancer patients. Interestingly, its effect is mediated by targeting Ras chaperones that serve as key coordinators for Ras proper folding and delivery, thus offering a novel target for cancer therapy. The development of new FTS analogs has revealed that the specific modifications to the FTS carboxyl group by esterification and amidation yielded compounds with improved growth inhibitory activity. When FTS was combined with additional therapeutic agents its activity toward Ras was significantly augmented. FTS should be tested not only in cancer but also for genetic diseases associated with abnormal Ras signaling, as well as for various inflammatory and autoimmune disturbances, where Ras plays a major role. We conclude that FTS has a great potential both as a safe anticancer drug and as a promising immune modulator agent.
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Affiliation(s)
- Yoel Kloog
- Department of Neurobiology, Faculty of Life Sciences, Tel-Aviv University, Ramat-Aviv, Israel.
| | - Galit Elad-Sfadia
- Department of Neurobiology, Faculty of Life Sciences, Tel-Aviv University, Ramat-Aviv, Israel
| | - Roni Haklai
- Department of Neurobiology, Faculty of Life Sciences, Tel-Aviv University, Ramat-Aviv, Israel
| | - Adam Mor
- Department of Medicine, New York University School of Medicine, New York, New York, USA; Department of Pathology, New York University School of Medicine, New York, New York, USA
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24
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Abstract
AbstractRas genes are pre-eminent genes that are frequently linked with cancer biology. The functional loss of ras protein caused by various point mutations within the gene, is established as a prognostic factor for the genesis of a constitutively active Ras-MAPK pathway leading to cancer. Ras signaling circuit follows a complex pathway, which connects many signaling molecules and cells. Several strategies have come up for targeting mutant ras proteins for cancer therapy, however, the clinical benefits remain insignificant. Targeting the Ras-MAPK pathway is extremely complicated due its intricate networks involving several upstream and downstream regulators. Blocking oncogenic Ras is still in latent stage and requires alternative approaches to screen the genes involved in Ras transformation. Understanding the mechanism of Ras induced tumorigenesis in diverse cancers and signaling networks will open a path for drug development and other therapeutic approaches.
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25
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Sun D, Haddad R, Kraniak JM, Horne SD, Tainsky MA. RAS/MEK-independent gene expression reveals BMP2-related malignant phenotypes in the Nf1-deficient MPNST. Mol Cancer Res 2013; 11:616-27. [PMID: 23423222 DOI: 10.1158/1541-7786.mcr-12-0593] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Malignant peripheral nerve sheath tumor (MPNST) is a type of soft tissue sarcoma that occurs in carriers of germline mutations in Nf1 gene as well as sporadically. Neurofibromin, encoded by the Nf1 gene, functions as a GTPase-activating protein (GAP) whose mutation leads to activation of wt-RAS and mitogen-activated protein kinase (MAPK) signaling in neurofibromatosis type I (NF1) patients' tumors. However, therapeutic targeting of RAS and MAPK have had limited success in this disease. In this study, we modulated NRAS, mitogen-activated protein/extracellular signal-regulated kinase (MEK)1/2, and neurofibromin levels in MPNST cells and determined gene expression changes to evaluate the regulation of signaling pathways in MPNST cells. Gene expression changes due to neurofibromin modulation but independent of NRAS and MEK1/2 regulation in MPNST cells indicated bone morphogenetic protein 2 (Bmp2) signaling as a key pathway. The BMP2-SMAD1/5/8 pathway was activated in NF1-associated MPNST cells and inhibition of BMP2 signaling by LDN-193189 or short hairpin RNA (shRNA) to BMP2 decreased the motility and invasion of NF1-associated MPNST cells. The pathway-specific gene changes provide a greater understanding of the complex role of neurofibromin in MPNST pathology and novel targets for drug discovery.
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Affiliation(s)
- Daochun Sun
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Wayne State University, Detroit, Michigan 48201, USA
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26
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Mashiach-Farkash E, Rak R, Elad-Sfadia G, Haklai R, Carmeli S, Kloog Y, Wolfson HJ. Computer-based identification of a novel LIMK1/2 inhibitor that synergizes with salirasib to destabilize the actin cytoskeleton. Oncotarget 2013; 3:629-39. [PMID: 22776759 PMCID: PMC3442289 DOI: 10.18632/oncotarget.525] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Neurofibromin regulates cell motility via three distinct GTPase pathways acting through two different domains, the Ras GTPase-activating protein-related domain (GRD) and the pre-GRD domain. First, the GRD domain inhibits Ras-dependent changes in cell motility through the mitogen activated protein cascade. Second, it also regulates Rho-dependent (Ras-independent) changes by activating LIM kinase 2 (LIMK2), an enzyme that phosphorylates and inactivates cofilin (an actin-depolymerizing factor). Third, the pre-GRD domain acts through the Rac1 GTPase, that activate the P21 activated kinase 1 (PAK1)-LIMK1-cofilin pathway. We employed molecular modeling to identify a novel inhibitor of LIMK1/2. The active sites of an ephrin-A receptor (EphA3) and LIMK2 showed marked similarity (60%). On testing a known inhibitor of EphA3, we found that it fits to the LIMK1/2-ATP binding site and to the latter's substrate-binding pockets. We identified a similar compound, T56-LIMKi, and found that it inhibits LIMK1/2 kinase activities. It blocked the phosphorylation of cofilin which led to actin severance and inhibition of tumor cell migration, tumor cell growth, and anchorage-independent colony formation in soft agar. Because modulation of LIMK by neurofibromin is not affected by the Ras inhibitor Salirasib, we examined the combined effect of Salirasib and T56-LIMKi each of which can affect cell motility by a distinct pathway. We found that their combined action on cell proliferation and stress-fiber formation in neurofibromin-deficient cells was synergistic. We suggest that this drug combination may be developed for treatment of neurofibromatosis and cancer.
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Affiliation(s)
- Efrat Mashiach-Farkash
- The Blavatnik School of Computer Science, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel-Aviv University, Tel Aviv, Israel
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27
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Dai C, Santagata S, Tang Z, Shi J, Cao J, Kwon H, Bronson RT, Whitesell L, Lindquist S. Loss of tumor suppressor NF1 activates HSF1 to promote carcinogenesis. J Clin Invest 2012; 122:3742-54. [PMID: 22945628 DOI: 10.1172/jci62727] [Citation(s) in RCA: 101] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2012] [Accepted: 07/12/2012] [Indexed: 01/25/2023] Open
Abstract
Intrinsic stress response pathways are frequently mobilized within tumor cells. The mediators of these adaptive mechanisms and how they contribute to carcinogenesis remain poorly understood. A striking example is heat shock factor 1 (HSF1), master transcriptional regulator of the heat shock response. Surprisingly, we found that loss of the tumor suppressor gene neurofibromatosis type 1 (Nf1) increased HSF1 levels and triggered its activation in mouse embryonic fibroblasts. As a consequence, Nf1-/- cells acquired tolerance to proteotoxic stress. This activation of HSF1 depended on dysregulated MAPK signaling. HSF1, in turn, supported MAPK signaling. In mice, Hsf1 deficiency impeded NF1-associated carcinogenesis by attenuating oncogenic RAS/MAPK signaling. In cell lines from human malignant peripheral nerve sheath tumors (MPNSTs) driven by NF1 loss, HSF1 was overexpressed and activated, which was required for tumor cell viability. In surgical resections of human MPNSTs, HSF1 was overexpressed, translocated to the nucleus, and phosphorylated. These findings reveal a surprising biological consequence of NF1 deficiency: activation of HSF1 and ensuing addiction to this master regulator of the heat shock response. The loss of NF1 function engages an evolutionarily conserved cellular survival mechanism that ultimately impairs survival of the whole organism by facilitating carcinogenesis.
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Affiliation(s)
- Chengkai Dai
- Whitehead Institute for Biomedical Research, Cambridge, Massachusetts 02142, USA.
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Gong M, Ma J, Li M, Zhou M, Hock JM, Yu X. MicroRNA-204 critically regulates carcinogenesis in malignant peripheral nerve sheath tumors. Neuro Oncol 2012; 14:1007-17. [PMID: 22718995 DOI: 10.1093/neuonc/nos124] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Malignant peripheral nerve sheath tumors (MPNSTs) are highly aggressive soft tissue sarcomas accounting for 3%-10% of all soft tissue sarcomas. Neurofibromatosis type 1 (NF1) is the most important known risk factor. MPNSTs are often diagnosed at an advanced stage when distant metastases have developed. Although surgical resection remains the main treatment for MPNSTs, complete surgical resection is rarely possible. The prognosis for patients with MPNSTs is poor. There is an urgent need for improved therapies. To this end, we investigated whether microRNA (miR), specifically miR-204, might be implicated in MPNSTs because it is located at a cancer-associated genomic region exhibiting high frequency of loss of heterozygosity in tumors. We show that miR-204 expression is downregulated in NF1 and non-NF1 MPNST tumor tissues and in tumor cell lines. Restoring miR-204 expression in MPNST cell lines STS26T (non-NF1), ST88-14 (NF1), and T265p21 (NF1) significantly reduces cellular proliferation, migration, and invasion in vitro. Restoring miR-204 expression in STS26T decreases tumor growth and malignant progression in vivo. We also report that miR-204 inhibits Ras signaling and expression of high mobility group gene A2. These findings support the hypothesis that miR-204 plays critical roles in MPNST development and tumor progression. miR-204 may represent a novel biomarker for diagnosis and a candidate target with which to develop effective therapies for MPNSTs.
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Affiliation(s)
- Meng Gong
- Laboratory of Endocrinology and Metabolism, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan, P.R. China
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Liu DZ, Ander BP. Cell cycle inhibition without disruption of neurogenesis is a strategy for treatment of aberrant cell cycle diseases: an update. ScientificWorldJournal 2012; 2012:491737. [PMID: 22547985 PMCID: PMC3323905 DOI: 10.1100/2012/491737] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2011] [Accepted: 11/17/2011] [Indexed: 12/12/2022] Open
Abstract
Since publishing our earlier report describing a strategy for the treatment of central nervous system (CNS) diseases by inhibiting the cell cycle and without disrupting neurogenesis (Liu et al. 2010), we now update and extend this strategy to applications in the treatment of cancers as well. Here, we put forth the concept of "aberrant cell cycle diseases" to include both cancer and CNS diseases, the two unrelated disease types on the surface, by focusing on a common mechanism in each aberrant cell cycle reentry. In this paper, we also summarize the pharmacological approaches that interfere with classical cell cycle molecules and mitogenic pathways to block the cell cycle of tumor cells (in treatment of cancer) as well as to block the cell cycle of neurons (in treatment of CNS diseases). Since cell cycle inhibition can also block proliferation of neural progenitor cells (NPCs) and thus impair brain neurogenesis leading to cognitive deficits, we propose that future strategies aimed at cell cycle inhibition in treatment of aberrant cell cycle diseases (i.e., cancers or CNS diseases) should be designed with consideration of the important side effects on normal neurogenesis and cognition.
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Affiliation(s)
- Da-Zhi Liu
- Department of Neurology and the MIND Institute, University of California at Davis, Sacramento, CA 95817, USA.
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30
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Abstract
The RAS oncogenes (HRAS, NRAS and KRAS) comprise the most frequently mutated class of oncogenes in human cancers (33%), thus stimulating intensive effort in developing anti-Ras inhibitors for cancer treatment. Despite intensive effort, to date, no effective anti-Ras strategies have successfully made it to the clinic. We present an overview of past and ongoing strategies to inhibit oncogenic Ras in cancer. Since approaches to directly target mutant Ras have not been successful, most efforts have focused on indirect approaches to block Ras membrane association or downstream effector signaling. While inhibitors of effector signaling are currently under clinical evaluation, genome-wide unbiased genetic screens have identified novel directions for future anti-Ras drug discovery.
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31
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Sun D, Tainsky MA, Haddad R. Oncogene Mutation Survey in MPNST Cell Lines Enhances the Dominant Role of Hyperactive Ras in NF1 Associated Pro-Survival and Malignancy. TRANSLATIONAL ONCOGENOMICS 2012; 5:1-7. [PMID: 22346343 PMCID: PMC3273949 DOI: 10.4137/tog.s8830] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Malignant peripheral nerve sheath tumors (MPNST) are a type of soft tissue sarcoma that can be associated with germline mutations in Neurofibromatosis type 1 (NF1) or may occur sporadically. Although the etiology of MPNST is poorly understood, it is clear that a loss of function of the NF1 gene, encoding a Ras-GAP, is an important factor in the tumorigenesis of the inherited form of MPNST. Tumor latency in NF1 patients suggests that additional mutational events are probably required for malignancy. In order to define oncogene mutations associated with 5 MPNST cell lines, we assayed the 238 most frequent mutations in 19 commonly activated oncogenes using mass spectroscopy-based analysis. All 238 mutation sites in the assayed oncogenes were determined to harbor only wild-type sequences. These data suggest that hyperactive Ras resulting from the loss function of neurofibromin may be sufficient to set up the direction of malignant transformation of Schwann cells to MPNST.
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Affiliation(s)
- Daochun Sun
- Center for Molecluar Medicine and Genetics, Wayne State University School of Medicine, Wayne State University, Detroit, MI 48201
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32
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Ma J, Li M, Hock J, Yu X. Hyperactivation of mTOR critically regulates abnormal osteoclastogenesis in neurofibromatosis Type 1. J Orthop Res 2012; 30:144-52. [PMID: 21748792 DOI: 10.1002/jor.21497] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2010] [Accepted: 06/15/2011] [Indexed: 02/05/2023]
Abstract
Individuals with nerofibromatosis Type 1 (NF1) frequently suffer a spectrum of bone pathologies, such as abnormal skeletal development (scoliosis, congenital bowing, and congenital pseudoarthroses, etc), lower bone mineral density with increased fracture risk. These skeletal problems may result, in part, from abnormal osteoclastogenesis. Enhanced RAS/PI3K activity has been reported to contribute to abnormal osteoclastogenesis in Nf1 heterozygous (Nf1+/-) mice. However, the specific downstream pathways linked to NF1 abnormal osteoclastogenesis have not been defined. Our aim was to determine whether mammalian target of rapamycin (mTOR) was a key effector responsible for abnormal osteoclastogenesis in NF1. Primary osteoclast-like cells (OCLs) were cultured from Nf1 wild-type (Nf1+/+) and Nf1+/- mice. Compared to Nf1+/+ controls, there were 20% more OCLs induced from Nf1+/- mice. Nf1+/- OCLs were larger and contained more nuclei. Hyperactive mTOR signaling was detected in Nf1+/- OCLs. Inhibition of mTOR signaling by rapamycin in Nf1+/- OCLs abrogated abnormalities in cellular size and number. Moreover, we found that hyperactive mTOR signaling induced abnormal osteoclastogenesis major through hyper-proliferation. Our research suggests that neurofibromin directly regulates osteoclastogenesis through mTOR signaling pathway. Inhibiting mTOR may represent a viable strategy to treat NF1 bone diseases.
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Affiliation(s)
- Junrong Ma
- West China Hospital, Sichuan University, Chengdu, People's Republic of China
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33
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Rudrapatna VA, Cagan RL, Das TK. Drosophila cancer models. Dev Dyn 2011; 241:107-18. [PMID: 22038952 DOI: 10.1002/dvdy.22771] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/27/2011] [Indexed: 01/20/2023] Open
Abstract
Cancer is driven by complex genetic and cellular mechanisms. Recently, the Drosophila community has become increasingly interested in exploring cancer issues. The Drosophila field has made seminal contributions to many of the mechanisms that are fundamental to the cancer process; several of these mechanisms have already been validated in vertebrates. Less well known are the Drosophila field's early direct contributions to the cancer field: some of the earliest tumor suppressors were identified in flies. In this review, we identify major contributions that Drosophila studies have made toward dissecting the pathways and mechanisms underlying tumor progression. We also highlight areas, such as drug discovery, where we expect Drosophila studies to make a major scientific impact in the future.
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Affiliation(s)
- Vivek A Rudrapatna
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, New York 10029, USA
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34
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Inhibition of contact sensitivity by farnesylthiosalicylic acid-amide, a potential Rap1 inhibitor. J Invest Dermatol 2011; 131:2040-8. [PMID: 21716322 DOI: 10.1038/jid.2011.152] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We hypothesized that Ras proximate 1 (Rap1) functions as an additional target for farnesylthiosalicylic acid (FTS) or its derivatives, and that the inhibition of Rap1 in lymphocytes by these agents may represent a method for treating inflammatory disorders. Indeed, we found that FTS-amide (FTS-A) was able to inhibit the elicitation phase of delayed cutaneous hypersensitivity in vivo. This effect was associated with the inhibition of Rap1 more than with the inhibition of Harvey rat sarcoma viral oncogene (Ras). Moreover, FTS-A inhibited Rap1 and contact sensitivity far better than FTS. We suggest that FTS-A may serve as a possible therapeutic tool in contact sensitivity in particular and T-cell-mediated inflammation in general.
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35
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Barkan B, Kloog Y, Ehrlich M. Phenotypic reversion of invasive neurofibromin-deficient schwannoma by FTS: Ras inhibition reduces BMP4/Erk/Smad signaling. Mol Cancer Ther 2011; 10:1317-26. [PMID: 21632464 DOI: 10.1158/1535-7163.mct-10-1087] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Neurofibromin-deficient (Nf1(-/-)) malignant peripheral nerve sheath tumors (MPNST) are highly invasive, refractory to chemotherapy, and characterized by overactivated Ras. Ras activates mitogenic pathways and regulates morphogenic programs--such as those induced by bone morphogenetic proteins (BMP) and TGF-β. The role of such a cross-talk in determining the phenotype and transformation potential of MPNSTs is unknown. Here, we used MPNST cell lines and selective Ras inhibition with S-trans,trans-farnesylthiosalicylic-acid (FTS; salirasib) in conjunction with specific inhibitors of TGF-β and BMP signaling. FTS perturbed signaling of BMP4 and TGF-β1 to Smad-dependent and Erk-dependent pathways. Furthermore, FTS inhibited motility and spreading, reduced the gelatinase secretion, eliminated the expression and activation of regulators of cell-matrix interaction, and altered gene expression. These phenomena are indicative of a phenotypic reversion of NF1-deficient cells by FTS. Inhibition of BMP4 and TGF-β by noggin and SB-431542, respectively, mimicked the FTS-mediated effects on adhesion, spreading, and cell morphology. This strongly suggests that a cross-talk among TGF-β superfamily ligands and Ras plays a significant role in the transformation of NF1(-/-) MPNSTs. Our results support the therapeutic potential of FTS, in conjuncture with BMP and TGF-β pathway inhibitors, toward the inhibition of mitogenic and morphogenic signaling pathways and the alleviation of NF1 symptoms.
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Affiliation(s)
- Batya Barkan
- Department of Neurobiology, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
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36
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Bustinza-Linares E, Kurzrock R, Tsimberidou AM. Salirasib in the treatment of pancreatic cancer. Future Oncol 2010; 6:885-91. [PMID: 20528225 DOI: 10.2217/fon.10.71] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The Ras family of genes is involved in the cellular regulation of proliferation, differentiation, cell adhesion and apoptosis. The K-ras gene is mutated in over 90% of pancreatic cancer cases. Salirasib (S-trans,trans-farnesylthiosalycilic acid [FTS]) is a synthetic small molecule that acts as a potent Ras inhibitor. It is a farnesylcysteine mimetic that selectively disrupts the association of active RAS proteins with the plasma membrane. Animal studies demonstrated that salirasib inhibited tumor growth, downregulated gene expression in the cell cycle and Ras signaling pathways. In a clinical study of salirasib combined with standard doses of gemcitabine, it was demonstrated that the two drugs have no overlapping pharmacokinetics. The salirasib recommended dose was 600 mg twice daily and the progression-free survival was 4.7 months. Future studies will determine whether salirasib adds to the anti-tumor activity of drugs approved by the US FDA for pancreatic cancer.
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Affiliation(s)
- Ernesto Bustinza-Linares
- Department of Investigational Cancer Therapeutics, The Phase I Clinical Trials Program, Unit 455, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, USA
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37
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Chai G, Liu N, Ma J, Li H, Oblinger JL, Prahalad AK, Gong M, Chang LS, Wallace M, Muir D, Guha A, Phipps RJ, Hock JM, Yu X. MicroRNA-10b regulates tumorigenesis in neurofibromatosis type 1. Cancer Sci 2010; 101:1997-2004. [PMID: 20550523 PMCID: PMC11159772 DOI: 10.1111/j.1349-7006.2010.01616.x] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
MicroRNAs (miRNAs) are frequently deregulated in human tumors, and play important roles in tumor development and progression. The pathological roles of miRNAs in neurofibromatosis type 1 (NF1) tumorigenesis are largely unknown. We demonstrated that miR-10b was up-regulated in primary Schwann cells isolated from NF1 neurofibromas and in cell lines and tumor tissues from malignant peripheral nerve sheath tumors (MPNSTs). Intriguingly, a significantly high level of miR-10b correlated with low neurofibromin expression was found in a neuroectodermal cell line: Ewing's sarcoma SK-ES-1 cells. Antisense inhibiting miR-10b in NF1 MPNST cells reduced cell proliferation, migration and invasion. Furthermore, we showed that NF1 mRNA was the target for miR-10b. Overexpression of miR-10b in 293T cells suppressed neurofibromin expression and activated RAS signaling. Antisense inhibition of miR-10b restored neurofibromin expression in SK-ES-1 cells, and decreased RAS signaling independent of neurofibromin in NF1 MPNST cells. These results suggest that miR-10b may play an important role in NF1 tumorigenesis through targeting neurofibromin and RAS signaling.
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Affiliation(s)
- Guolin Chai
- Maine Institute for Human Genetics & Health, Bangor, Maine
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38
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Kraniak JM, Sun D, Mattingly RR, Reiners JJ, Tainsky MA. The role of neurofibromin in N-Ras mediated AP-1 regulation in malignant peripheral nerve sheath tumors. Mol Cell Biochem 2010; 344:267-76. [PMID: 20680410 DOI: 10.1007/s11010-010-0551-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2010] [Accepted: 07/23/2010] [Indexed: 11/29/2022]
Abstract
Plexiform neurofibromas commonly found in patients with Neurofibromatosis type I (NF1) have a 5% risk of being transformed into malignant peripheral nerve sheath tumors (MPNST). Germline mutations in the NF1 gene coding for neurofibromin, which is a Ras GTPase activating protein (RasGAP) and a negative regulator of Ras, result in an upregulation of the Ras pathway. We established a direct connection between neurofibromin deficiency and downstream effectors of Ras in cell lines from MPNST patients by demonstrating that knockdown of NF1 expression using siRNA in a NF1 wild type MPNST cell line, STS-26T, activates the Ras/ERK1,2 pathway and increases AP-1 binding and activity. We believe this is the first time the transactivation of AP-1 has been linked directly to neurofibromin deficiency in a disease relevant MPNST cell line. Previously, we have shown that N-Ras is constitutively activated in cell lines derived from independent MPNSTs from NF1 patients. We therefore sought to analyze the role of the N-Ras pathway in deregulating AP-1 transcriptional activity. We show that STS-26T clones conditionally expressing oncogenic N-Ras show increased phosphorylated ERK1,2 and phosphorylated JNK expression concomitant with increased AP-1 activity. MAP kinase pathways (ERK1,2 and JNK) were further examined in ST88-14, a neurofibromin-deficient MPNST cell line. The basal activity of ERK1,2 but not JNK was found to increase AP-1 activity. These experiments further confirmed the link between the loss of neurofibromin and increased activity of Ras/MAP kinase pathways and the activation of downstream transcriptional mechanisms in MPNSTs from NF1 patients.
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Affiliation(s)
- Janice M Kraniak
- Programs in Molecular Biology and Genetics, Barbara Ann Karmanos Cancer Institute, Detroit, MI 48201, USA
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39
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Goldberg L, Ocherashvilli A, Daniels D, Last D, Cohen ZR, Tamar G, Kloog Y, Mardor Y. Salirasib (farnesyl thiosalicylic acid) for brain tumor treatment: a convection-enhanced drug delivery study in rats. Mol Cancer Ther 2008; 7:3609-16. [PMID: 19001442 DOI: 10.1158/1535-7163.mct-08-0488] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Our aim was to assess the ability of convection-enhanced drug delivery (CED), a novel approach of direct delivery of drugs into brain tissue and brain tumors, to treat brain tumors using salirasib (farsnesyl thiosalicylic acid). CED was achieved by continuous infusion of drugs via intracranial catheters, thus enabling convective distribution of high drug concentrations over large volumes while avoiding systemic toxicity. Several phase II/III CED-based trials are currently in progress but have yet to overcome two major pitfalls of this methodology (the difficulty in attaining efficient CED and the significant nonspecific neurotoxicity caused by high drug doses in the brain). In this study, we addressed both issues by employing our previously described novel CED imaging and increased efficiency methodologies to exclusively target the activated form of the Ras oncogene in a 9L gliosarcoma rat model. The drug we used was salirasib, a highly specific Ras inhibitor shown to exert its suppressive effects on growth and migration of proliferating tumor cells in in vitro and in vivo models, including human glioblastoma, without affecting normal tissues. The results show a significant decrease in tumor growth rate in salirasib-treated rats relative to vehicle-treated rats as well as a significant correlation between CED efficacy and tumor growth rate with no observed toxicity despite drug concentrations an order of magnitude higher than previously detected in the brain. The results show that CED of salirasib is efficient and nontoxic for the treatment of glioblastoma in a rat model, thus suggesting that it may be considered for clinical application.
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Affiliation(s)
- Liat Goldberg
- Department of Neurobiochemistry, The George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel Aviv, Israel
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40
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Goldberg L, Haklai R, Bauer V, Heiss A, Kloog Y. New Derivatives of Farnesylthiosalicylic Acid (Salirasib) for Cancer Treatment: Farnesylthiosalicylamide Inhibits Tumor Growth in Nude Mice Models. J Med Chem 2008; 52:197-205. [DOI: 10.1021/jm801165r] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Liat Goldberg
- Department of Neurobiology, The George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel Aviv, Israel, Concordia Pharmaceuticals, Inc., 1550 Sawgrass Corporate Parkway, Sunrise, Florida, Ricerca Biosciences, 7528 Auburn Road, Concord, Ohio
| | - Roni Haklai
- Department of Neurobiology, The George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel Aviv, Israel, Concordia Pharmaceuticals, Inc., 1550 Sawgrass Corporate Parkway, Sunrise, Florida, Ricerca Biosciences, 7528 Auburn Road, Concord, Ohio
| | - Victor Bauer
- Department of Neurobiology, The George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel Aviv, Israel, Concordia Pharmaceuticals, Inc., 1550 Sawgrass Corporate Parkway, Sunrise, Florida, Ricerca Biosciences, 7528 Auburn Road, Concord, Ohio
| | - Aaron Heiss
- Department of Neurobiology, The George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel Aviv, Israel, Concordia Pharmaceuticals, Inc., 1550 Sawgrass Corporate Parkway, Sunrise, Florida, Ricerca Biosciences, 7528 Auburn Road, Concord, Ohio
| | - Yoel Kloog
- Department of Neurobiology, The George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel Aviv, Israel, Concordia Pharmaceuticals, Inc., 1550 Sawgrass Corporate Parkway, Sunrise, Florida, Ricerca Biosciences, 7528 Auburn Road, Concord, Ohio
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41
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Harmon B, Ratner L. Induction of the Galpha(q) signaling cascade by the human immunodeficiency virus envelope is required for virus entry. J Virol 2008; 82:9191-205. [PMID: 18632858 PMCID: PMC2546909 DOI: 10.1128/jvi.00424-08] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2008] [Accepted: 07/08/2008] [Indexed: 12/13/2022] Open
Abstract
Binding of human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein (Env) with the primary receptor CD4 and one of two coreceptors, CXCR4 or CCR5, activates a signaling cascade resulting in Rac-1 GTPase activation and stimulation of actin cytoskeletal reorganizations critical for HIV-1-mediated membrane fusion. The mechanism by which HIV-1 Env induces Rac-1 activation and subsequent actin cytoskeleton rearrangement is unknown. In this study, we show that Env-mediated Rac-1 activation is dependent on the activation of Galpha(q) and its downstream targets. Fusion and Rac-1 activation are mediated by Galpha(q) and phospholipase C (PLC), as shown by attenuation of fusion and Rac-1 activation in cells either expressing small interfering RNA (siRNA) targeting Galpha(q) or treated with the PLC inhibitor U73122. Rac-1 activation and fusion were also blocked by multiple protein kinase C inhibitors, by inhibitors of intracellular Ca2+ release, by Pyk2-targeted siRNA, and by the Ras inhibitor S-trans,trans-farnesylthiosalicylic acid (FTS). Fusion was blocked without altering cell viability or cell surface localization of CD4 and CCR5. Similar results were obtained when cell fusion was induced by Env expressed on viral and cellular membranes and when cell lines or primary cells were the target. Treatment with inhibitors and siRNA specific for Galpha(i) or Galpha(s) signaling mediators had no effect on Env-mediated Rac-1 activation or cell fusion, indicating that the Galpha(q) pathway alone is responsible. These results could provide a new focus for therapeutic intervention with drugs targeting host signaling mediators rather than viral molecules, a strategy which is less likely to result in resistance.
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Affiliation(s)
- Brooke Harmon
- Division of Molecular Oncology, Washington University School of Medicine, St. Louis, Missouri, USA
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42
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Abstract
Neurofibromatosis type 1 (NF1) is a dominantly inherited multi-system disorder. Major features include pigmentary abnormalities, benign tumors of the nerve sheath (neurofibromas), malignant tumors, learning disabilities, and skeletal dysplasia. The NF1 gene functions as a tumor suppressor, but haploinsuffiency probably accounts for some aspects of the non-tumor phenotype. The protein product, neurofibromin, is a Ras GTPase-activating protein, and various Ras pathway inhibitors are being tested in preclinical models and clinical trials for effectiveness in treating NF1 complications. This month in BMC Medicine, a paper by Kolanczyk et al describes a preclinical mouse model for tibial dysplasia and provides evidence that the drug lovastatin - in use to treat cardiovascular disease - may be beneficial, opening the door to clinical trials in humans.
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Affiliation(s)
- Bruce R Korf
- Department of Genetics, University of Alabama at Birmingham, 1530 Third Avenue South, Kaul 230, Birmingham, AL, USA.
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43
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Ambrosini G, Cheema HS, Seelman S, Teed A, Sambol EB, Singer S, Schwartz GK. Sorafenib inhibits growth and mitogen-activated protein kinase signaling in malignant peripheral nerve sheath cells. Mol Cancer Ther 2008; 7:890-6. [PMID: 18413802 DOI: 10.1158/1535-7163.mct-07-0518] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Malignant peripheral nerve sheath tumors (MPNST) are soft-tissue tumors with a very poor prognosis and largely resistant to chemotherapy. MPNSTs are characterized by activation of the Ras pathway by loss of tumor suppressor neurofibromatosis type 1. In view of this, MPNST may be susceptible to inhibition of the activated Ras/Raf/mitogen-activated protein kinase pathway by the B-Raf inhibitor sorafenib. MPNST (MPNST and ST8814) and dedifferentiated liposarcoma (LS141 and DDLS) human tumor cell lines were characterized for Ras activation and B-Raf expression. Tumor cells were treated with sorafenib and examined for growth inhibition, inhibition of phospho-MEK, phospho-ERK, cell cycle arrest, and changes in cyclin D1 and pRb expression. MPNSTs were sensitive to sorafenib at nanomolar concentrations. This appeared to be due to inhibition of phospho-MEK, phospho-ERK, suppression of cyclin D1, and hypophosphorylation of pRb at the CDK4-specific sites, resulting in a G(1) cell cycle arrest. These effects were not seen in the liposarcoma cells, which either did not express B-Raf or showed decreased Ras activation. Small interfering RNA-mediated depletion of B-Raf in MPNSTs also induced a G(1) cell cycle arrest in these cells, with a marked inhibition of cyclin D1 expression and Rb phosphorylation, whereas depletion of C-Raf did not affect either. With growth inhibition at the low nanomolar range, sorafenib, by inhibiting the mitogen-activated protein kinase pathway, may prove to be a novel therapy for patients with MPNST.
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Affiliation(s)
- Grazia Ambrosini
- Laboratory of New Drug Development, Department of Medicine, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021, USA
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44
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Leukemia-associated NF1 inactivation in patients with pediatric T-ALL and AML lacking evidence for neurofibromatosis. Blood 2008; 111:4322-8. [DOI: 10.1182/blood-2007-06-095075] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Abstract
Neurofibromatosis type 1 (NF1) is an autosomal dominant genetic disorder caused by mutations in the NF1 gene. Patients with NF1 have a higher risk to develop juvenile myelomonocytic leukemia (JMML) with a possible progression toward acute myeloid leukemia (AML). In an oligo array comparative genomic hybridization–based screening of 103 patients with pediatric T-cell acute lymphoblastic leukemia (T-ALL) and 71 patients with MLL-rearranged AML, a recurrent cryptic deletion, del(17)(q11.2), was identified in 3 patients with T-ALL and 2 patients with MLL-rearranged AML. This deletion has previously been described as a microdeletion of the NF1 region in patients with NF1. However, our patients lacked clinical NF1 symptoms. Mutation analysis in 4 of these del(17)(q11.2)-positive patients revealed that mutations in the remaining NF1 allele were present in 3 patients, confirming its role as a tumor-suppressor gene in cancer. In addition, NF1 inactivation was confirmed at the RNA expression level in 3 patients tested. Since the NF1 protein is a negative regulator of the RAS pathway (RAS-GTPase activating protein), homozygous NF1 inactivation represent a novel type I mutation in pediatric MLL-rearranged AML and T-ALL with a predicted frequency that is less than 10%. NF1 inactivation may provide an additional proliferative signal toward the development of leukemia.
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Rotblat B, Ehrlich M, Haklai R, Kloog Y. The Ras inhibitor farnesylthiosalicylic acid (Salirasib) disrupts the spatiotemporal localization of active Ras: a potential treatment for cancer. Methods Enzymol 2008; 439:467-89. [PMID: 18374183 DOI: 10.1016/s0076-6879(07)00432-6] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Chronic activation of Ras proteins by mutational activation or by growth factor stimulation is a common occurrence in many human cancers and was shown to induce and be required for tumor growth. Even if additional genetic defects are present, "correction" of the Ras defect has been shown to reverse Ras-dependent tumorigenesis. One way to block Ras protein activity is by interfering with their spatiotemporal localization in cellular membranes or in membrane microdomains, a prerequisite for Ras signaling and biological activity. Detailed reports describe the use of this method in studies employing farnesylthiosalicylic acid (FTS, Salirasib), a Ras farnesylcysteine mimetic, which selectively disrupts the association of chronically active Ras proteins with the plasma membrane. FTS competes with Ras for binding to Ras-escort proteins, which possess putative farnesyl-binding domains and interact only with the activated form of Ras proteins, thereby promoting Ras nanoclusterization in the plasma membrane and robust signals. This chapter presents three-dimensional time-lapse images that track the FTS-induced inhibition of membrane-activated Ras in live cells on a real-time scale. It also describes a mechanistic model that explains FTS selectivity toward activated Ras. Selective blocking of activated Ras proteins results in the inhibition of Ras transformation in vitro and in animal models, with no accompanying toxicity. Phase I clinical trials have demonstrated a safe profile for oral FTS, with minimal side effects and promising activity in hematological malignancies. Salirasib is currently undergoing trials in patients with pancreatic cancer and with nonsmall cell lung cancer, with or without identified K-Ras mutations. The findings might indicate whether with the disruption of the spatiotemporal localization of oncogenic Ras proteins and the targeting of prenyl-binding domains by anticancer drugs is worth developing as a means of cancer treatment.
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Affiliation(s)
- Barak Rotblat
- Department of Neurobiochemistry, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
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Abstract
PURPOSE OF REVIEW The delineation of syndromes carrying a predisposition to malignancy has led to great insights into the molecular biology of malignancy. Many such syndromes have cutaneous findings which can precede the development of neoplasia. Early recognition of the cutaneous stigmata of the genodermatoses with malignant potential can lead to early diagnosis and initiation of proper screening and treatment when indicated. RECENT FINDINGS This article reviews 'classic' genodermatoses with malignant potential and highlights recent recommendations for screening and treatment. Additionally more recently delineated syndromes and their cutaneous findings are discussed. SUMMARY Certain inherited syndromes with a risk of neoplasia exhibit characteristic cutaneous findings. Recognition of these findings by the astute practitioner can lead to early intervention which can impact the course of these rare diseases.
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Affiliation(s)
- Jennifer D Holman
- Department of Dermatology, University of Missouri Columbia, Missouri 65212, USA
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Abstract
✓Discovery that the Schwann cell is the primary cell type responsible for both the neurofibroma as well as the schwannoma has proven to represent a crucial milestone in understanding the pathogenesis of peripheral nerve tumor development. This information and related findings have served as a nidus for research aimed at more fully characterizing this family of conditions. Recent discoveries in the laboratory have clarified an understanding of the molecular mechanisms underlying the pathogenesis of benign peripheral nerve tumors. Similarly, the mechanisms whereby idiopathic and syndromic (NF1- andNF2-associated) nerve sheath tumors progress to malignancy are being elucidated. This detailed understanding of the molecular pathogenesis of peripheral nerve tumors provides the information necessary to create a new generation of therapies tailored specifically to the prevention, cessation, or reversal of pathological conditions at the fundamental level of dysfunction. The authors review the data that have helped to elucidate the molecular pathogenesis of this category of conditions, explore the current progress toward exploitation of these findings, and discuss potential therapeutic avenues for future research.
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Affiliation(s)
- Jonathan Riley
- Department of Neurosciences and the Center for Neurological Restoration, Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA
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Zundelevich A, Elad-Sfadia G, Haklai R, Kloog Y. Suppression of lung cancer tumor growth in a nude mouse model by the Ras inhibitor salirasib (farnesylthiosalicylic acid). Mol Cancer Ther 2007; 6:1765-73. [PMID: 17541036 DOI: 10.1158/1535-7163.mct-06-0706] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Aberrant Ras pathway functions contribute to the malignant phenotype of lung cancers. Inhibitors of Ras might therefore be considered as potential drugs for lung cancer therapy. Here, we show that the Ras inhibitor farnesylthiosalicylic acid (salirasib) inhibits proliferation of human lung cancer cells harboring a mutated K-ras gene (A549, H23, or HTB54) or overexpressing a growth factor receptor (H1299 or HTB58) and enhances the cytotoxic effect of the chemotherapeutic drug gemcitabine. Salirasib inhibited active K-Ras in A549 cells, reversed their transformed morphology, and inhibited their anchorage-independent growth in vitro. Tumor growth in A549 and HTB58 cell nude mouse models was inhibited by i.p. administration of salirasib. P.o. formulated salirasib also inhibited A549 cell tumor growth. Our results suggest that p.o. salirasib may be considered as a potential treatment for lung cancer therapy.
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Affiliation(s)
- Adi Zundelevich
- Department of Neurobiochemistry, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
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Haklai R, Elad-Sfadia G, Egozi Y, Kloog Y. Orally administered FTS (salirasib) inhibits human pancreatic tumor growth in nude mice. Cancer Chemother Pharmacol 2007; 61:89-96. [PMID: 17909812 DOI: 10.1007/s00280-007-0451-6] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2006] [Accepted: 02/27/2007] [Indexed: 10/23/2022]
Abstract
BACKGROUND S-trans,trans-farnesylthiosalicylic acid (salirasib, FTS) is a synthetic small molecule that acts as a potent Ras inhibitor. Salirasib inhibits specifically both oncogenically activated Ras and growth factor receptor-mediated Ras activation, resulting in the inhibition of Ras-dependent tumor growth. The objectives of this study were to develop a sensitive LC-MS/MS assay for determination of FTS in plasma, to assess the bioavailabilty of FTS after oral administration to mice, and then to examine the efficacy of orally administered FTS for inhibition of tumor growth in a nude mouse model. METHODS FTS was isolated from mouse plasma by liquid chromatography on a Columbus 5-mum particle size, 50 x 2 mm id column with a methanol/5 mM ammonium acetate (80/20) mobile phase (isocratic elution) at a flow rate of 0.3 ml/min. MS/MS was performed on a PE Sciex API 365 with Turbo Ion Spray as interface and negative ion ionization; parent ion (m/z): 357.2; daughter ion (m/z) 153.2; retention time 2.3 min. For plasma analysis, the amount of analyte in each sample was calculated by comparing response of the analyte in that sample to a nine-point standard curve linear over the range 3-1000 ng/ml. Pharmacokinetic studies were performed in mice following intraperitoneal dosing (20 mk/kg in PBS) or oral dosing (40 mg/kg in either 0.5% aqueous CMC or corn oil). Panc-1 tumor growth in nude mice was determined following daily oral dosing with FTS in 0.5% CMC (40, 60, or 80 mg/kg), or in combination with weekly gemcitabine (30 mg/kg). RESULTS Salirasib was readily detected in mouse plasma by LC-MS/MS at a detection limit of 3 ng/ml. For each route of administration, t (max) was 1 h and t (1/2) ranged from 1.86 to 2.66 h. Compared to IP administration, the oral bioavailabilty of FTS was 69.5% for oral CMC and 55% for oral corn oil suspensions, while clearance and volume of distribution were higher in both oral preparations. The orally administered salirasib inhibited panc-1 tumor growth in a dose dependent manner (67% reduction in tumor weight at the highest dose, P < 0.002 vs. control, n = 10 mice per group) and at a 40 mg/kg daily dose was synergistic with gemcitabine (83% increase in survival rate, n = 8 mice per group). CONCLUSIONS Salirasib exhibits good bioavailabilty after oral administration, as determined by a highly sensitive method for quantification in plasma. The orally available Ras inhibitor salirasib inhibited growth in nude mice, and may thus be considered for clinical trials.
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Affiliation(s)
- Roni Haklai
- Department of Neurobiochemistry, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, 69978, Israel
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Shapira S, Barkan B, Friedman E, Fridman E, Kloog Y, Stein R. The tumor suppressor neurofibromin confers sensitivity to apoptosis by Ras-dependent and Ras-independent pathways. Cell Death Differ 2006; 14:895-906. [PMID: 17096025 DOI: 10.1038/sj.cdd.4402057] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Neurofibromatosis type 1 (NF1) is characterized by a high incidence of benign and malignant tumors attributed to loss of function of Nf1, which encodes neurofibromin, a tumor suppressor with Ras-GAP activity. Neurofibromin deficiency typically causes chronic activation of Ras, considered the major contributor to manifestation of NF1. Resistance to radio- and chemotherapy are typical of NF1-associated tumors, but the underlying mechanism is unknown. Here, we investigated interrelationships between neurofibromin expression, Ras activity, and sensitivity to apoptosis. Neurofibromin-deficient mouse embryonic fibroblasts (MEFs) and human NF1 tumor cells were more resistant than neurofibromin-expressing cells to apoptosis. Moreover, Nf1(-/-), Nf1(+/-), and Nf1(+/+) MEFs exhibited gene-dosage-related resistance to apoptosis. Resistance of the Nf1-deficient cells was mediated by two survival pathways: a Ras-dependent pathway, and a Ras-independent pathway promoted by the lack of an NF1-GRD-independent proapoptotic action of neurofibromin. Therefore, besides its Ras-dependent growth inhibition, neurofibromin can exert tumor suppression via a proapoptotic effect.
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Affiliation(s)
- S Shapira
- Department of Neurobiochemistry, George S Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Israel
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