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Wang P, Laster K, Jia X, Dong Z, Liu K. Targeting CRAF kinase in anti-cancer therapy: progress and opportunities. Mol Cancer 2023; 22:208. [PMID: 38111008 PMCID: PMC10726672 DOI: 10.1186/s12943-023-01903-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Accepted: 11/16/2023] [Indexed: 12/20/2023] Open
Abstract
The RAS/mitogen-activated protein kinase (MAPK) signaling cascade is commonly dysregulated in human malignancies by processes driven by RAS or RAF oncogenes. Among the members of the RAF kinase family, CRAF plays an important role in the RAS-MAPK signaling pathway, as well as in the progression of cancer. Recent research has provided evidence implicating the role of CRAF in the physiological regulation and the resistance to BRAF inhibitors through MAPK-dependent and MAPK-independent mechanisms. Nevertheless, the effectiveness of solely targeting CRAF kinase activity remains controversial. Moreover, the kinase-independent function of CRAF may be essential for lung cancers with KRAS mutations. It is imperative to develop strategies to enhance efficacy and minimize toxicity in tumors driven by RAS or RAF oncogenes. The review investigates CRAF alterations observed in cancers and unravels the distinct roles of CRAF in cancers propelled by diverse oncogenes. This review also seeks to summarize CRAF-interacting proteins and delineate CRAF's regulation across various cancer hallmarks. Additionally, we discuss recent advances in pan-RAF inhibitors and their combination with other therapeutic approaches to improve treatment outcomes and minimize adverse effects in patients with RAF/RAS-mutant tumors. By providing a comprehensive understanding of the multifaceted role of CRAF in cancers and highlighting the latest developments in RAF inhibitor therapies, we endeavor to identify synergistic targets and elucidate resistance pathways, setting the stage for more robust and safer combination strategies for cancer treatment.
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Affiliation(s)
- Penglei Wang
- Department of Pathophysiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, 450000, China
- Tianjian Laboratory for Advanced Biomedical Sciences, Zhengzhou, 450052, Henan, China
- China-US (Henan) Hormel Cancer Institute, Zhengzhou, 450000, China
| | - Kyle Laster
- China-US (Henan) Hormel Cancer Institute, Zhengzhou, 450000, China
| | - Xuechao Jia
- Department of Pathophysiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, 450000, China
- Tianjian Laboratory for Advanced Biomedical Sciences, Zhengzhou, 450052, Henan, China
- China-US (Henan) Hormel Cancer Institute, Zhengzhou, 450000, China
| | - Zigang Dong
- Department of Pathophysiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, 450000, China.
- Tianjian Laboratory for Advanced Biomedical Sciences, Zhengzhou, 450052, Henan, China.
- China-US (Henan) Hormel Cancer Institute, Zhengzhou, 450000, China.
- Department of Pathophysiology, School of Basic Medical Sciences, China-US (Henan) Hormel Cancer Institute, AMS, College of Medicine, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, 450001, Henan, China.
| | - Kangdong Liu
- Department of Pathophysiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, 450000, China.
- Tianjian Laboratory for Advanced Biomedical Sciences, Zhengzhou, 450052, Henan, China.
- China-US (Henan) Hormel Cancer Institute, Zhengzhou, 450000, China.
- Department of Pathophysiology, School of Basic Medical Sciences, China-US (Henan) Hormel Cancer Institute, AMS, College of Medicine, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, 450001, Henan, China.
- Basic Medicine Sciences Research Center, Academy of Medical Sciences, Zhengzhou University, Zhengzhou, 450052, Henan, China.
- State Key Laboratory of Esophageal Cancer Prevention and Treatment, Zhengzhou University, Zhengzhou, 450000, Henan, China.
- Provincial Cooperative Innovation Center for Cancer Chemoprevention, Zhengzhou University, Zhengzhou, 450000, Henan, China.
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2
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Singh A, Sonawane P, Kumar A, Singh H, Naumovich V, Pathak P, Grishina M, Khalilullah H, Jaremko M, Emwas AH, Verma A, Kumar P. Challenges and Opportunities in the Crusade of BRAF Inhibitors: From 2002 to 2022. ACS OMEGA 2023; 8:27819-27844. [PMID: 37576670 PMCID: PMC10413849 DOI: 10.1021/acsomega.3c00332] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 02/27/2023] [Indexed: 08/15/2023]
Abstract
Serine/threonine-protein kinase B-Raf (BRAF; RAF = rapidly accelerated fibrosarcoma) plays an important role in the mitogen-activated protein kinase (MAPK) signaling cascade. Somatic mutations in the BRAF gene were first discovered in 2002 by Davies et al., which was a major breakthrough in cancer research. Subsequently, three different classes of BRAF mutants have been discovered. This class includes class I monomeric mutants (BRAFV600), class II BRAF homodimer mutants (non-V600), and class III BRAF heterodimers (non-V600). Cancers caused by these include melanoma, thyroid cancer, ovarian cancer, colorectal cancer, nonsmall cell lung cancer, and others. In this study, we have highlighted the major binding pockets in BRAF protein, their active and inactive conformations with inhibitors, and BRAF dimerization and its importance in paradoxical activation and BRAF mutation. We have discussed the first-, second-, and third-generation drugs approved by the Food and Drug Administration and drugs under clinical trials with all four different binding approaches with DFG-IN/OUT and αC-IN/OUT for BRAF protein. We have investigated particular aspects and difficulties with all three generations of inhibitors. Finally, this study has also covered recent developments in synthetic BRAF inhibitors (from their discovery in 2002 to 2022), their unique properties, and importance in inhibiting BRAF mutants.
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Affiliation(s)
- Ankit
Kumar Singh
- Department
of Pharmaceutical Sciences and Natural Products, Central University of Punjab, Ghudda, Bathinda 151401, India
| | - Pankaj Sonawane
- Department
of Pharmaceutical Sciences and Natural Products, Central University of Punjab, Ghudda, Bathinda 151401, India
| | - Adarsh Kumar
- Department
of Pharmaceutical Sciences and Natural Products, Central University of Punjab, Ghudda, Bathinda 151401, India
| | - Harshwardhan Singh
- Department
of Pharmaceutical Sciences and Natural Products, Central University of Punjab, Ghudda, Bathinda 151401, India
| | - Vladislav Naumovich
- Laboratory
of Computational Modeling of Drugs, Higher Medical and Biological
School, South Ural State University, Chelyabinsk 454008, Russia
| | - Prateek Pathak
- Laboratory
of Computational Modeling of Drugs, Higher Medical and Biological
School, South Ural State University, Chelyabinsk 454008, Russia
| | - Maria Grishina
- Laboratory
of Computational Modeling of Drugs, Higher Medical and Biological
School, South Ural State University, Chelyabinsk 454008, Russia
| | - Habibullah Khalilullah
- Department
of Pharmaceutical Chemistry and Pharmacognosy, Unaizah College of
Pharmacy, Qassim University, Unayzah 51911, Saudi Arabia
| | - Mariusz Jaremko
- Smart-Health
Initiative and Red Sea Research Center, Division of Biological and
Environmental Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Abdul-Hamid Emwas
- Core
Laboratories, King Abdullah University of
Science and Technology, Thuwal 23955-6900, Saudi
Arabia
| | - Amita Verma
- Bioorganic
and Medicinal Chemistry Research Laboratory, Department of Pharmaceutical
Sciences, Sam Higginbottom University of
Agriculture, Technology and Sciences, Prayagraj 211007, India
| | - Pradeep Kumar
- Department
of Pharmaceutical Sciences and Natural Products, Central University of Punjab, Ghudda, Bathinda 151401, India
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3
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Oktem EK, Yazar M. Drug Repositioning Identifies Six Drug Candidates for Systemic Autoimmune Diseases by Integrative Analyses of Transcriptomes from Scleroderma, Systemic Lupus Erythematosus, and Sjogren's Syndrome. OMICS : A JOURNAL OF INTEGRATIVE BIOLOGY 2022; 26:683-693. [PMID: 36378860 DOI: 10.1089/omi.2022.0138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The mechanisms of systemic autoimmune diseases (ADs) are still not clearly understood. Understanding the etiology of systemic ADs and identifying new therapeutic targets require a systems science approach. Using publicly available transcriptome data and bioinformatic analysis, we investigated the differential gene expression profiles of patients with scleroderma, systemic lupus erythematosus, and Sjogren's syndrome. Of these common differentially expressed gene signatures, 208 were regulated in the same direction (either upregulated or downregulated in all datasets) and used for drug repositioning. Six small molecule drug candidates (KU-0063794, YM-155 [sepantronium bromide], MST-312 [telomerase inhibitor IX], PLX-4720, ZM 336372, and 528116.cdx [PIK-75]) were discovered by drug repositioning as potential therapeutics for systemic ADs. The Search Tool for Chemical Interactions was used to find the anticipated target genes of the repositioned molecules. The PI3K/AKT pathway topped the list of common enriched pathways with the most anticipated target genes of the six repositioned small molecules. We also report here the molecular docking findings on the binding affinity between the repositioned drug candidates and genes from the protein-protein interaction network modules of anticipated target genes. Taken together, this study provides new insights and opens up new possibilities on both pathogenesis and treatment of systemic ADs through drug repositioning.
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Affiliation(s)
- Elif Kubat Oktem
- Department of Molecular Biology and Genetics, Faculty of Engineering and Natural Sciences, Istanbul Medeniyet University, Istanbul, Turkey
| | - Metin Yazar
- Department of Genetics and Bioengineering, Faculty of Engineering and Natural Sciences, Istanbul Okan University, Istanbul, Turkey
- Department of Bioengineering, Faculty of Engineering, Marmara University, Istanbul, Turkey
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4
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Mori M, Cazzaniga G, Meneghetti F, Villa S, Gelain A. Insights on the Modulation of SIRT5 Activity: A Challenging Balance. Molecules 2022; 27:4449. [PMID: 35889322 PMCID: PMC9316768 DOI: 10.3390/molecules27144449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 07/08/2022] [Accepted: 07/09/2022] [Indexed: 02/01/2023] Open
Abstract
SIRT5 is a member of the Sirtuin family, a class of deacetylating enzymes consisting of seven isoforms, involved in the regulation of several processes, including gene expression, metabolism, stress response, and aging. Considering that the anomalous activity of SIRT5 is linked to many pathological conditions, we present herein an overview of the most interesting modulators, with the aim of contributing to further development in this field.
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Affiliation(s)
| | | | | | - Stefania Villa
- Department of Pharmaceutical Sciences, University of Milan, Via L. Mangiagalli 25, 20133 Milano, Italy; (M.M.); (G.C.); (F.M.); (A.G.)
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Egal ESA, Jacenik D, Soares HP, Beswick EJ. Translational challenges in pancreatic neuroendocrine tumor immunotherapy. Biochim Biophys Acta Rev Cancer 2021; 1876:188640. [PMID: 34695532 PMCID: PMC10695297 DOI: 10.1016/j.bbcan.2021.188640] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 09/19/2021] [Accepted: 10/18/2021] [Indexed: 12/28/2022]
Abstract
Pancreatic neuroendocrine tumors are rare types of pancreatic cancer formed from islet cells of pancreas. Clinical presentation of pancreatic neuroendocrine tumors depends on both tumor progression and hormone secretion status, which generate several complications in both diagnosis and treatment. Despite numerous strategies, treatment of patients with pancreatic neuroendocrine tumors still needs improvement. It is suggested that immune response modulation may be essential in the regulation of pancreatic neuroendocrine tumor progression and patient's symptomology. Accumulating evidence indicates that immunotherapy seems to be a promising treatment option for patients with pancreatic neuroendocrine tumors. Nevertheless, several challenges in pre-clinical and clinical studies are present. This review provides knowledge about microenvironment of pancreatic neuroendocrine tumors including significance of cytokine and chemokine as well as specific immune cell types. Additionally, in vitro and in vivo models of pancreatic neuroendocrine tumors and translational challenges are highlighted.
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Affiliation(s)
- Erika Said Abu Egal
- Division of Gastroenterology, Department of Internal Medicine, University of Utah, UT, Salt Lake City, United States
| | - Damian Jacenik
- Division of Gastroenterology, Department of Internal Medicine, University of Utah, UT, Salt Lake City, United States; Division of Oncology, Department of Internal Medicine, Huntsman Cancer Institute at the University of Utah, UT, Salt Lake City, United States; Department of Cytobiochemistry, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland
| | - Heloisa Prado Soares
- Division of Oncology, Department of Internal Medicine, Huntsman Cancer Institute at the University of Utah, UT, Salt Lake City, United States.
| | - Ellen J Beswick
- Division of Gastroenterology, Department of Internal Medicine, University of Utah, UT, Salt Lake City, United States
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6
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Schreck KC, Morin A, Zhao G, Allen AN, Flannery P, Glantz M, Green AL, Jones C, Jones KL, Kilburn LB, Nazemi KJ, Samuel D, Sanford B, Solomon DA, Wang J, Pratilas CA, Nicolaides T, Mulcahy Levy JM. Deconvoluting Mechanisms of Acquired Resistance to RAF Inhibitors in BRAF V600E-Mutant Human Glioma. Clin Cancer Res 2021; 27:6197-6208. [PMID: 34433654 PMCID: PMC8595717 DOI: 10.1158/1078-0432.ccr-21-2660] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 08/12/2021] [Accepted: 08/23/2021] [Indexed: 11/16/2022]
Abstract
PURPOSE Selective RAF-targeted therapy is effective in some patients with BRAFV600E-mutated glioma, though emergent and adaptive resistance occurs through ill-defined mechanisms. EXPERIMENTAL DESIGN Paired pre-/post- RAF inhibitor (RAFi)-treated glioma samples (N = 15) were obtained and queried for treatment-emergent genomic alterations using DNA and RNA sequencing (RNA-seq). Functional validation of putative resistance mechanisms was performed using established and patient-derived BRAFV600E-mutant glioma cell lines. RESULTS Analysis of 15 tissue sample pairs identified 13 alterations conferring putative resistance were identified among nine paired samples (including mutations involving ERRFI1, BAP1, ANKHD1, and MAP2K1). We performed functional validation of mechanisms of resistance, including loss of NF1, PTEN, or CBL, in BRAFV600E-mutant glioma lines, and demonstrate they are capable of conferring resistance in vitro. Knockdown of CBL resulted in increased EGFR expression and phosphorylation, a possible mechanism for maintaining ERK signaling within the cell. Combination therapy with a MEKi or EGFR inhibitor was able to overcome resistance to BRAFi, in NF1 knockdown and CBL knockdown, respectively. Restoration of wild-type PTEN in B76 cells (PTEN-/-) restored sensitivity to BRAFi. We identified and validated CRAF upregulation as a mechanism of resistance in one resistant sample. RNA-seq analysis identified two emergent expression patterns in resistant samples, consistent with expression patterns of known glioma subtypes. CONCLUSIONS Resistance mechanisms to BRAFi in glioma are varied and may predict effective precision combinations of targeted therapy, highlighting the importance of a personalized approach.
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Affiliation(s)
- Karisa C Schreck
- Department of Neurology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, Baltimore, Maryland
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, Baltimore, Maryland
- Department of Neurosurgery, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, Baltimore, Maryland
| | - Andrew Morin
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado
- Morgan Adams Foundation Pediatric Brain Tumor Research Program, Children's Hospital Colorado, Aurora, Colorado
| | - Guisheng Zhao
- Department of Pediatrics, NYU Langone Health, New York, New York
| | - Amy N Allen
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, Baltimore, Maryland
- Department of Pediatrics, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, Baltimore, Maryland
| | - Patrick Flannery
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado
- Morgan Adams Foundation Pediatric Brain Tumor Research Program, Children's Hospital Colorado, Aurora, Colorado
| | - Michael Glantz
- Department of Neurosurgery, Penn State College of Medicine, Hershey, Pennsylvania
- Department of Oncology, Penn State College of Medicine, Hershey, Pennsylvania
| | - Adam L Green
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado
- Morgan Adams Foundation Pediatric Brain Tumor Research Program, Children's Hospital Colorado, Aurora, Colorado
- Center for Cancer and Blood Disorders, Children's Hospital Colorado, Aurora, Colorado
| | - Chris Jones
- Division of Molecular Pathology, Institute of Cancer Research, London, United Kingdom
| | | | - Lindsay B Kilburn
- Division of Oncology and the Brain Tumor Institute, Children's National Hospital, Washington, DC
| | - Kellie J Nazemi
- Department of Pediatrics, Oregon Health & Science University, Portland, Oregon
| | - David Samuel
- Department of Hematology-Oncology, Valley Children's Healthcare, Madera, California
| | - Bridget Sanford
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado
| | - David A Solomon
- Department of Pathology, University of California, San Francisco, California
| | - Jiawan Wang
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, Baltimore, Maryland
- Department of Pediatrics, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, Baltimore, Maryland
| | - Christine A Pratilas
- Department of Neurology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, Baltimore, Maryland
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, Baltimore, Maryland
- Department of Pediatrics, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, Baltimore, Maryland
| | | | - Jean M Mulcahy Levy
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado.
- Morgan Adams Foundation Pediatric Brain Tumor Research Program, Children's Hospital Colorado, Aurora, Colorado
- Center for Cancer and Blood Disorders, Children's Hospital Colorado, Aurora, Colorado
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, Colorado
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7
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Maharjan CK, Ear PH, Tran CG, Howe JR, Chandrasekharan C, Quelle DE. Pancreatic Neuroendocrine Tumors: Molecular Mechanisms and Therapeutic Targets. Cancers (Basel) 2021; 13:5117. [PMID: 34680266 PMCID: PMC8533967 DOI: 10.3390/cancers13205117] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 10/08/2021] [Accepted: 10/09/2021] [Indexed: 12/16/2022] Open
Abstract
Pancreatic neuroendocrine tumors (pNETs) are unique, slow-growing malignancies whose molecular pathogenesis is incompletely understood. With rising incidence of pNETs over the last four decades, larger and more comprehensive 'omic' analyses of patient tumors have led to a clearer picture of the pNET genomic landscape and transcriptional profiles for both primary and metastatic lesions. In pNET patients with advanced disease, those insights have guided the use of targeted therapies that inhibit activated mTOR and receptor tyrosine kinase (RTK) pathways or stimulate somatostatin receptor signaling. Such treatments have significantly benefited patients, but intrinsic or acquired drug resistance in the tumors remains a major problem that leaves few to no effective treatment options for advanced cases. This demands a better understanding of essential molecular and biological events underlying pNET growth, metastasis, and drug resistance. This review examines the known molecular alterations associated with pNET pathogenesis, identifying which changes may be drivers of the disease and, as such, relevant therapeutic targets. We also highlight areas that warrant further investigation at the biological level and discuss available model systems for pNET research. The paucity of pNET models has hampered research efforts over the years, although recently developed cell line, animal, patient-derived xenograft, and patient-derived organoid models have significantly expanded the available platforms for pNET investigations. Advancements in pNET research and understanding are expected to guide improved patient treatments.
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Affiliation(s)
- Chandra K. Maharjan
- Department of Neuroscience and Pharmacology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA;
| | - Po Hien Ear
- Department of Surgery, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA; (P.H.E.); (C.G.T.); (J.R.H.)
| | - Catherine G. Tran
- Department of Surgery, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA; (P.H.E.); (C.G.T.); (J.R.H.)
| | - James R. Howe
- Department of Surgery, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA; (P.H.E.); (C.G.T.); (J.R.H.)
| | - Chandrikha Chandrasekharan
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA;
| | - Dawn E. Quelle
- Department of Neuroscience and Pharmacology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA;
- Department of Pathology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
- Holden Comprehensive Cancer Center, University of Iowa, Iowa City, IA 52242, USA
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8
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Aristizabal Prada ET, Heinzle V, Knösel T, Nölting S, Spöttl G, Maurer J, Spitzweg C, Angele M, Schmidt N, Beuschlein F, Stalla GK, Blaser R, Kuhn KA, Auernhammer CJ. Tropomyosin receptor kinase: a novel target in screened neuroendocrine tumors. Endocr Relat Cancer 2018; 25:547-560. [PMID: 29563190 DOI: 10.1530/erc-17-0201] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 03/21/2018] [Indexed: 01/27/2023]
Abstract
Tropomyosin receptor kinase (Trk) inhibitors are investigated as a novel targeted therapy in various cancers. We investigated the in vitro effects of the pan-Trk inhibitor GNF-5837 in human neuroendocrine tumor (NET) cells. The human neuroendocrine pancreatic BON1, bronchopulmonary NCI-H727 and ileal GOT1 cell lines were treated with GNF-5837 alone and in combination with everolimus. Cell viability decreased in a time- and dose-dependent manner in GOT1 cells in response to GNF-5837 treatment, while treatment in BON1 and NCI-H727 cells showed no effect on cellular viability. Trk receptor expression determined GNF-5837 sensitivity. GNF-5837 caused downregulation of PI3K-Akt-mTOR signaling, Ras-Raf-MEK-ERK signaling, the cell cycle and increased apoptotic cell death. The combinational treatment of GNF-5837 with everolimus showed a significant enhancement in inhibition of cell viability vs single substance treatments, due to a cooperative PI3K-Akt-mTOR and Ras-Raf-MEK-ERK pathway downregulation, as well as an enhanced cell cycle component downregulation. Immunohistochemical staining for Trk receptors were performed using a tissue microarray containing 107 tumor samples of gastroenteropancreatic NETs. Immunohistochemical staining with TrkA receptor and pan-Trk receptor antibodies revealed a positive staining in pancreatic NETs in 24.2% (8/33) and 33.3% (11/33), respectively. We demonstrated that the pan-Trk inhibitor GNF-5837 has promising anti-tumoral properties in human NET cell lines expressing the TrkA receptor. Immunohistochemical or molecular screening for Trk expression particularly in pancreatic NETs might serve as predictive marker for molecular targeted therapy with Trk inhibitors.
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Affiliation(s)
- Elke Tatjana Aristizabal Prada
- Interdisciplinary Center of Neuroendocrine Tumors of the GastroEnteroPancreatic System (GEPNET-KUM), Klinikum der Universität München, Ludwig-Maximilians-University of Munich, Campus Grosshadern, Munich, Germany
- Department of Internal Medicine 2, University-Hospital, Klinikum der Universität München, Ludwig-Maximilians-University of Munich, Munich, Germany
- Department of Internal Medicine 4, University-Hospital, Klinikum der Universität München, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Vera Heinzle
- Interdisciplinary Center of Neuroendocrine Tumors of the GastroEnteroPancreatic System (GEPNET-KUM), Klinikum der Universität München, Ludwig-Maximilians-University of Munich, Campus Grosshadern, Munich, Germany
- Department of Internal Medicine 2, University-Hospital, Klinikum der Universität München, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Thomas Knösel
- Interdisciplinary Center of Neuroendocrine Tumors of the GastroEnteroPancreatic System (GEPNET-KUM), Klinikum der Universität München, Ludwig-Maximilians-University of Munich, Campus Grosshadern, Munich, Germany
- Institute of Pathology, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Svenja Nölting
- Interdisciplinary Center of Neuroendocrine Tumors of the GastroEnteroPancreatic System (GEPNET-KUM), Klinikum der Universität München, Ludwig-Maximilians-University of Munich, Campus Grosshadern, Munich, Germany
- Department of Internal Medicine 2, University-Hospital, Klinikum der Universität München, Ludwig-Maximilians-University of Munich, Munich, Germany
- Department of Internal Medicine 4, University-Hospital, Klinikum der Universität München, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Gerald Spöttl
- Interdisciplinary Center of Neuroendocrine Tumors of the GastroEnteroPancreatic System (GEPNET-KUM), Klinikum der Universität München, Ludwig-Maximilians-University of Munich, Campus Grosshadern, Munich, Germany
- Department of Internal Medicine 2, University-Hospital, Klinikum der Universität München, Ludwig-Maximilians-University of Munich, Munich, Germany
- Department of Internal Medicine 4, University-Hospital, Klinikum der Universität München, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Julian Maurer
- Interdisciplinary Center of Neuroendocrine Tumors of the GastroEnteroPancreatic System (GEPNET-KUM), Klinikum der Universität München, Ludwig-Maximilians-University of Munich, Campus Grosshadern, Munich, Germany
- Department of Internal Medicine 2, University-Hospital, Klinikum der Universität München, Ludwig-Maximilians-University of Munich, Munich, Germany
- Department of Internal Medicine 4, University-Hospital, Klinikum der Universität München, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Christine Spitzweg
- Interdisciplinary Center of Neuroendocrine Tumors of the GastroEnteroPancreatic System (GEPNET-KUM), Klinikum der Universität München, Ludwig-Maximilians-University of Munich, Campus Grosshadern, Munich, Germany
- Department of Internal Medicine 2, University-Hospital, Klinikum der Universität München, Ludwig-Maximilians-University of Munich, Munich, Germany
- Department of Internal Medicine 4, University-Hospital, Klinikum der Universität München, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Martin Angele
- Interdisciplinary Center of Neuroendocrine Tumors of the GastroEnteroPancreatic System (GEPNET-KUM), Klinikum der Universität München, Ludwig-Maximilians-University of Munich, Campus Grosshadern, Munich, Germany
- Department of General, Visceral, Transplantation, Vascular and Thoracic Surgery, University-Hospital, Klinikum der Universität München, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Nina Schmidt
- Interdisciplinary Center of Neuroendocrine Tumors of the GastroEnteroPancreatic System (GEPNET-KUM), Klinikum der Universität München, Ludwig-Maximilians-University of Munich, Campus Grosshadern, Munich, Germany
- Department of Internal Medicine 2, University-Hospital, Klinikum der Universität München, Ludwig-Maximilians-University of Munich, Munich, Germany
- Department of Internal Medicine 4, University-Hospital, Klinikum der Universität München, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Felix Beuschlein
- Department of Internal Medicine 4, University-Hospital, Klinikum der Universität München, Ludwig-Maximilians-University of Munich, Munich, Germany
- Klinik für Endokrinologie, Diabetologie und Klinische Ernährung, Universitätsspital Zürich, Zurich, Switzerland
| | - Günter K Stalla
- Clinical Neuroendocrinology, Max Planck Institute of Psychiatry, Munich, Germany
| | - Rainer Blaser
- Institute of Medical Statistics and Epidemiology, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany
| | - Klaus A Kuhn
- Institute of Medical Statistics and Epidemiology, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany
| | - Christoph J Auernhammer
- Interdisciplinary Center of Neuroendocrine Tumors of the GastroEnteroPancreatic System (GEPNET-KUM), Klinikum der Universität München, Ludwig-Maximilians-University of Munich, Campus Grosshadern, Munich, Germany
- Department of Internal Medicine 2, University-Hospital, Klinikum der Universität München, Ludwig-Maximilians-University of Munich, Munich, Germany
- Department of Internal Medicine 4, University-Hospital, Klinikum der Universität München, Ludwig-Maximilians-University of Munich, Munich, Germany
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9
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Aristizabal Prada ET, Auernhammer CJ. Targeted therapy of gastroenteropancreatic neuroendocrine tumours: preclinical strategies and future targets. Endocr Connect 2018; 7:R1-R25. [PMID: 29146887 PMCID: PMC5754510 DOI: 10.1530/ec-17-0286] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 11/16/2017] [Indexed: 12/12/2022]
Abstract
Molecular targeted therapy of advanced neuroendocrine tumours (NETs) of the gastroenteropancreatic (GEP) system currently encompasses approved therapy with the mammalian target of rapamycin (mTOR) inhibitor everolimus and the multi-tyrosinkinase inhibitor sunitinib. However, clinical efficacy of these treatment strategies is limited by low objective response rates and limited progression-free survival due to tumour resistance. Further novel strategies for molecular targeted therapy of NETs of the GEP system are needed. This paper reviews preclinical research models and signalling pathways in NETs of the GEP system. Preclinical and early clinical data on putative novel targets for molecular targeted therapy of NETs of the GEP system are discussed, including PI3K, Akt, mTORC1/mTORC2, GSK3, c-Met, Ras-Raf-MEK-ERK, embryogenic pathways (Hedgehog, Notch, Wnt/beta-catenin, TGF-beta signalling and SMAD proteins), tumour suppressors and cell cycle regulators (p53, cyclin-dependent kinases (CDKs) CDK4/6, CDK inhibitor p27, retinoblastoma protein (Rb)), heat shock protein HSP90, Aurora kinase, Src kinase family, focal adhesion kinase and epigenetic modulation by histone deacetylase inhibitors.
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Affiliation(s)
- E T Aristizabal Prada
- Department of Internal Medicine IVCampus Grosshadern, University-Hospital, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - C J Auernhammer
- Department of Internal Medicine IVCampus Grosshadern, University-Hospital, Ludwig-Maximilians-University of Munich, Munich, Germany
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10
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Patel P, Galoian K. Molecular challenges of neuroendocrine tumors. Oncol Lett 2017; 15:2715-2725. [PMID: 29456718 DOI: 10.3892/ol.2017.7680] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 12/13/2017] [Indexed: 02/07/2023] Open
Abstract
Neuroendocrine tumors (NETs) are a very heterogeneous group that are thought to originate from the cells of the endocrine and nervous systems. These tumors develop in a number of organs, predominantly in the gastrointestinal and pulmonary systems. Clinical detection and diagnosis are reliable at the late stages when metastatic spread has occurred. However, traditional conventional therapies such as radiation and chemotherapy are not effective. In the majority of cases even surgical resection at that stage is unlikely to produce promising reusults. NETs present a serious clinical challenge, as the survival rates remain low, and as these rare tumors are very difficult to study, novel approaches and therapies are required. This review will highlight the important points of accumulated knowledge covering the molecular aspects of the role of neuroendocrine cells, hormonal peptides, the reasons for ectopic hormone production in NET, neuropeptides and epigenetic regulation as well as the other challenging questions that require further understanding.
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Affiliation(s)
- Parthik Patel
- Department of Orthopedic Surgery, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
| | - Karina Galoian
- Department of Orthopedic Surgery, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
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11
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Hughes RR, Shaaban KA, Zhang J, Cao H, Phillips GN, Thorson JS. OleD Loki as a Catalyst for Tertiary Amine and Hydroxamate Glycosylation. Chembiochem 2017; 18:363-367. [PMID: 28067448 PMCID: PMC5355705 DOI: 10.1002/cbic.201600676] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Indexed: 12/23/2022]
Abstract
We describe the ability of an engineered glycosyltransferase (OleD Loki) to catalyze the N-glycosylation of tertiary-amine-containing drugs and trichostatin hydroxamate glycosyl ester formation. As such, this study highlights the first bacterial model catalyst for tertiary-amine N-glycosylation and further expands the substrate scope and synthetic potential of engineered OleDs. In addition, this work could open the door to the discovery of similar capabilities among other permissive bacterial glycosyltransferases.
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Affiliation(s)
- Ryan R Hughes
- Center for Pharmaceutical Research and Innovation, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
| | - Khaled A Shaaban
- Center for Pharmaceutical Research and Innovation, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
| | - Jianjun Zhang
- Center for Pharmaceutical Research and Innovation, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
| | - Hongnan Cao
- Department of Chemistry, Rice University, P. O. Box 1892, MS 60, Houston, TX, 77251, USA
| | - George N Phillips
- Department of Chemistry, Rice University, P. O. Box 1892, MS 60, Houston, TX, 77251, USA
| | - Jon S Thorson
- Center for Pharmaceutical Research and Innovation, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
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12
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Wyche TP, Dammalapati A, Cho H, Harrison AD, Kwon GS, Chen H, Bugni TS, Jaskula-Sztul R. Thiocoraline activates the Notch pathway in carcinoids and reduces tumor progression in vivo. Cancer Gene Ther 2014; 21:518-25. [PMID: 25412645 PMCID: PMC4270822 DOI: 10.1038/cgt.2014.57] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Revised: 10/02/2014] [Accepted: 10/17/2014] [Indexed: 12/13/2022]
Abstract
Carcinoids are slow-growing neuroendocrine tumors (NETs) that are characterized by hormone overproduction; surgery is currently the only option for treatment. Activation of the Notch pathway has previously been shown to have a role in tumor suppression in NETs. The marine-derived thiodepsipeptide thiocoraline was investigated in vitro in two carcinoid cell lines (BON and H727). Carcinoid cells treated with nanomolar concentrations of thiocoraline resulted in a decrease in cell proliferation and an alteration of malignant phenotype evidenced by decrease of NET markers, ASCL-1, CgA, and NSE. Western blot analysis demonstrated the activation of Notch1 on the protein level in BON cells. Additionally, thiocoraline activated downstream Notch targets HES1, HES5, and HEY2. Thiocoraline effectively suppressed carcinoid cell growth by promoting cell cycle arrest in BON and H727 cells. An in vivo study demonstrated that thiocoraline, formulated with polymeric micelles, slowed carcinoid tumor progression. Thus, the therapeutic potential of thiocoraline, which induced activation of the Notch pathway, in carcinoid tumors was demonstrated.
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Affiliation(s)
- T P Wyche
- Pharmaceutical Sciences Division, University of Wisconsin-Madison, Madison, WI, USA
| | - A Dammalapati
- Department of Surgery Endocrine Research Laboratories, UW Carbone Cancer Center, University of Wisconsin-Madison, Madison, WI, USA
| | - H Cho
- Pharmaceutical Sciences Division, University of Wisconsin-Madison, Madison, WI, USA
| | - A D Harrison
- Department of Surgery Endocrine Research Laboratories, UW Carbone Cancer Center, University of Wisconsin-Madison, Madison, WI, USA
| | - G S Kwon
- Pharmaceutical Sciences Division, University of Wisconsin-Madison, Madison, WI, USA
| | - H Chen
- Department of Surgery Endocrine Research Laboratories, UW Carbone Cancer Center, University of Wisconsin-Madison, Madison, WI, USA
| | - T S Bugni
- Pharmaceutical Sciences Division, University of Wisconsin-Madison, Madison, WI, USA
| | - R Jaskula-Sztul
- Department of Surgery Endocrine Research Laboratories, UW Carbone Cancer Center, University of Wisconsin-Madison, Madison, WI, USA
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13
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Fazio N, Abdel-Rahman O, Spada F, Galdy S, De Dosso S, Capdevila J, Scarpa A. RAF signaling in neuroendocrine neoplasms: from bench to bedside. Cancer Treat Rev 2014; 40:974-9. [PMID: 24998490 DOI: 10.1016/j.ctrv.2014.06.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2014] [Revised: 06/16/2014] [Accepted: 06/17/2014] [Indexed: 12/23/2022]
Abstract
Neuroendocrine neoplasms are a low-incidence and heterogeneous group of malignancies. In the advanced stage, several therapeutic options can be discussed, including molecular-targeted agents, but biological predicting factors are lacking. A number of molecular targets have been studied over the last decade leading to several phase II studies; however, very few agents progressed to phase III clinical trials. The RAF family of proteins belongs to the mitogen-activated protein kinase (MAPK) pathway, that has a role in several types of cancers, particularly related to BRAF mutations. Indeed BRAF inhibitors have been reported as being effective, mainly in melanoma. However, in neuroendocrine neoplasms BRAF mutations are extremely rare and RAF-1 activation has been reported to inhibit tumor growth in a pre-clinical setting. Therefore, in this field, RAF-1 activators rather than BRAF inhibitors should be clinically investigated. This article reviews the basic science as well as clinical data of RAF signaling in advanced neuroendocrine neoplasms with special emphasis on the potential role of both RAF activators and inhibitors.
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Affiliation(s)
- Nicola Fazio
- Unit of Gastrointestinal Medical Oncology and Neuroendocrine Tumors, European Institute of Oncology, Milan, Italy.
| | - Omar Abdel-Rahman
- Clinical Oncology Department, Faculty of Medicine, Ain Shams University, Cairo, Egypt
| | - Francesca Spada
- Unit of Gastrointestinal Medical Oncology and Neuroendocrine Tumors, European Institute of Oncology, Milan, Italy
| | - Salvatore Galdy
- Unit of Gastrointestinal Medical Oncology and Neuroendocrine Tumors, European Institute of Oncology, Milan, Italy
| | - Sara De Dosso
- Oncology Institute of Southern Switzerland, Bellinzona, Switzerland
| | - Jaume Capdevila
- Medical Oncology Department, Vall d'Hebron University Hospital, Barcelona, Spain
| | - Aldo Scarpa
- Department of Pathology and Diagnostics, ARC-NET Research Center, University of Verona, Italy
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14
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Alhefdhi A, Burke JF, Redlich A, Kunnimalaiyaan M, Chen H. Leflunomide suppresses growth in human medullary thyroid cancer cells. J Surg Res 2013; 185:212-6. [PMID: 23816245 DOI: 10.1016/j.jss.2013.05.089] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Revised: 05/15/2013] [Accepted: 05/24/2013] [Indexed: 11/16/2022]
Abstract
BACKGROUND Medullary thyroid cancer (MTC) is a neuroendocrine tumor that arises from the calcitonin-secreting parafollicular cells of the thyroid gland. Leflunomide (LFN) is a disease-modifying antirheumatic drug approved for the treatment of rheumatoid arthritis, and its active metabolite teriflunomide has been identified as a potential anticancer drug. In this study we investigated the ability of LFN to similarly act as an anticancer drug by examining the effects of LFN treatment on MTC cells. METHODS Human MTC-TT cells were treated with LFN (25-150 μmol/L) and Western blotting was performed to measure levels of neuroendocrine markers. MTT assays were used to assess the effect of LFN treatment on cellular proliferation. RESULTS LFN treatment downregulated neuroendocrine markers ASCL1 and chromogranin A. Importantly, LFN significantly inhibited the growth of MTC cells in a dose-dependent manner. CONCLUSIONS Treatment with LFN decreased neuroendocrine tumor marker expression and reduced the cell proliferation in MTC cells. As the safety of LFN in human beings is well established, a clinical trial using this drug to treat patients with advanced MTC may be warranted.
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Affiliation(s)
- Amal Alhefdhi
- Endocrine Surgery Research, Department of Surgery, University of Wisconsin, and Carbon Cancer Center, Madison, Wisconsin
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15
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Somnay Y, Chen H, Kunnimalaiyaan M. Synergistic effect of pasireotide and teriflunomide in carcinoids in vitro. Neuroendocrinology 2013; 97:183-92. [PMID: 22965070 PMCID: PMC3546174 DOI: 10.1159/000341810] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Accepted: 07/09/2012] [Indexed: 11/19/2022]
Abstract
BACKGROUND/AIM Somatostatin (SST) analogs are mainstay for controlling tumor proliferation and hormone secretion in carcinoid patients. Recent data suggest that extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation may potentiate the anti-tumor effects of SST analogs in carcinoids. Additionally, ERK1/2 phosphorylating agents have been shown to suppress biomarker expression in carcinoids. Thus, Raf-1/MEK/ERK1/2 pathway activating drugs may be synergistic with SST analogs such as pasireotide (SOM230), which may be more effective than others in its class given its elevated receptor affinity and broader binding spectrum. Here, we investigate the effects of SOM230 in combination with teriflunomide (TFN), a Raf-1 activator, in a human carcinoid cell line. METHODS Human pancreatic carcinoid cells (BON) were incubated in TFN, SOM230 or a combination. Cell proliferation was measured using a rapid colorimetric assay. Western analysis was performed to analyze expression levels of achaete-scute complex-like 1 (ASCL1), chromogranin A (CgA), phosphorylated and total ERK1/2, and markers for apoptosis. RESULTS Combination treatment with SOM230 and TFN reduced cell growth beyond the additive effect of either drug alone. Combination indices (CI) fell below 1, thus quantifiably verifying synergy between both drugs as per the Chou-Talalay CI scale. Combined treatment also reduced ASCL1 and CgA expression beyond the additive effect of either drug alone. Furthermore, it increased levels of phosphorylated ERK1/2, cleaved poly(ADP)-ribose polymerase and caspase-3, and reduced levels of anti-apoptotic biomarkers. Elevated phosphorylated ERK1/2 expression following combination therapy may underlie the synergistic interaction between the two drugs. CONCLUSION Since efficacy is achieved at lower doses, combination therapy may palliate symptoms at low toxicity levels. Because each drug has already been evaluated in clinical trials, combinatorial drug trials are warranted.
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Affiliation(s)
- Yash Somnay
- University of Wisconsin School of Medicine and Public Health, Endocrine Surgery Research Laboratories, Department of Surgery, Madison, USA
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16
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Carter Y, Jaskula-Sztul R, Chen H, Mazeh H. Signaling pathways as specific pharmacologic targets for neuroendocrine tumor therapy: RET, PI3K, MEK, growth factors, and Notch. Neuroendocrinology 2013; 97:57-66. [PMID: 22343668 PMCID: PMC3360110 DOI: 10.1159/000335136] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2011] [Accepted: 11/11/2011] [Indexed: 12/21/2022]
Abstract
Neuroendocrine tumors are rare tumors with a common progenitor - the neural crest cell. Included in this category are pulmonary and gastrointestinal tract carcinoid tumors and medullary thyroid cancer. The majority of these tumors are sporadic in nature, however they can be hereditary. Medullary thyroid cancers can present sporadically, with other endocrine tumors, as in the complex of multiple endocrine neoplasias 1, 2A, or 2B, or as familial medullary thyroid cancer. These tumors can become evident at later stages, with metastases already present at the time of diagnosis. Despite the small size and rare incidence of gastrointestinal neuroendocrine (carcinoid) tumors, they can be debilitating when present. Their natural history presents as early lymph node and distant metastases, as well as symptoms of the carcinoid syndrome, which result from the overproduction and secretion of serotonin and somatostatin. As a consequence of their metastases, surgical resection is non-curative and hence there is a need for novel treatment strategies to address tumor burden and symptom control. There are multiple intracellular pathways which can be targeted, either individually or in combination, to address these tumors. Here, we review some of the intracellular pathways, and identify some specific targets, which are vital to the generation and propagation of neuroendocrine tumorigenesis, and thus, can be the foci of novel drug therapies. We also elaborate on present pharmacological strategies and clinical trials involving these intracellular pathways.
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Affiliation(s)
- Yvette Carter
- Section of Endocrine Surgery, Department of Surgery, University of Wisconsin, Madison, WI 53792, USA
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17
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Nölting S, Garcia E, Alusi G, Giubellino A, Pacak K, Korbonits M, Grossman AB. Combined blockade of signalling pathways shows marked anti-tumour potential in phaeochromocytoma cell lines. J Mol Endocrinol 2012; 49:79-96. [PMID: 22715163 PMCID: PMC4714579 DOI: 10.1530/jme-12-0028] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Currently, there is no completely effective therapy available for metastatic phaeochromocytomas (PCCs) and paragangliomas. In this study, we explore new molecular targeted therapies for these tumours, using one more benign (mouse phaeochromocytoma cell (MPC)) and one more malignant (mouse tumour tissue (MTT)) mouse PCC cell line - both generated from heterozygous neurofibromin 1 knockout mice. Several PCC-promoting gene mutations have been associated with aberrant activation of PI3K/AKT, mTORC1 and RAS/RAF/ERK signalling. We therefore investigated different agents that interfere specifically with these pathways, including antagonism of the IGF1 receptor by NVP-AEW541. We found that NVP-AEW541 significantly reduced MPC and MTT cell viability at relatively high doses but led to a compensatory up-regulation of ERK and mTORC1 signalling at suboptimal doses while PI3K/AKT inhibition remained stable. We subsequently investigated the effect of the dual PI3K/mTORC1/2 inhibitor NVP-BEZ235, which led to a significant decrease of MPC and MTT cell viability at doses below 50 nM but again increased ERK signalling. Accordingly, we next examined the combination of NVP-BEZ235 with the established agent lovastatin, as this has been described to inhibit ERK signalling. Lovastatin alone significantly reduced MPC and MTT cell viability at therapeutically relevant doses and inhibited both ERK and AKT signalling, but increased mTORC1/p70S6K signalling. Combination treatment with NVP-BEZ235 and lovastatin showed a significant additive effect in MPC and MTT cells and resulted in inhibition of both AKT and mTORC1/p70S6K signalling without ERK up-regulation. Simultaneous inhibition of PI3K/AKT, mTORC1/2 and ERK signalling suggests a novel therapeutic approach for malignant PCCs.
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Affiliation(s)
- Svenja Nölting
- Department of Endocrinology, William Harvey Research Institute and Barts Cancer Institute, Barts and the London School of Medicine, Queen Mary University of London, London, UK
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18
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Niu M, Sun Y, Liu B, Tang L, Qiu R. Differential effects of tautomycetin and its derivatives on protein phosphatase inhibition, immunosuppressive function and antitumor activity. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2012; 16:145-51. [PMID: 22563261 PMCID: PMC3339291 DOI: 10.4196/kjpp.2012.16.2.145] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/14/2012] [Revised: 04/01/2012] [Accepted: 04/03/2012] [Indexed: 12/03/2022]
Abstract
In the present work, we studied the structure-activity relationship (SAR) of tautomycetin (TMC) and its derivatives. Further, we demonstrated the correlation between the immunosuppressive fuction, anticancer activity and protein phosphatase type 1 (PP1) inhibition of TMC and its derivatives. We have prepared some TMC derivatives via combinatorial biosynthesis, isolation from fermentation broth or chemical degradation of TMC. We found that the immunosuppressive activity was correlated with anticancer activity for TMC and its analog compounds, indicating that TMC may home at the same targets for its immunosuppressive and anticancer activities. Interestingly, TMC-F1, TMC-D1 and TMC-D2 all retained significant, albeit reduced PP1 inhibitory activity compared to TMC. However, only TMC-D2 showed immunosuppressive and anticancer activities in studies carried out in cell lines. Moreover, TMC-Chain did not show any significant inhibitory activity towards PP1 but showed strong growth inhibitory effect. This observation implicates that the maleic anhydride moiety of TMC is critical for its phosphatase inhibitory activity whereas the C1-C18 moiety of TMC is essential for the inhibition of tumor cell proliferation. Furthermore, we measured in vivo phosphatase activities of PP1 in MCF-7 cell extracts treated with TMC and its related compounds, and the results indicate that the cytotoxicity of TMC doesn't correlate with its in vivo PP1 inhibition activity. Taken together, our study suggests that the immunosuppressive and anticancer activities of TMC are not due to the inhibition of PP1. Our results provide a novel insight for the elucidation of the underlying molecular mechanisms of TMC's important biological functions.
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Affiliation(s)
- Mingshan Niu
- Research Center for Molecular Medicine, Dalian University of Technology, Dalian 116023, China
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19
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Demirci I, Herold S, Kopp A, Flaßhove M, Klosterhalfen B, Janßen H. Overdiagnosis of a typical carcinoid tumor as an adenocarcinoma of the lung: a case report and review of the literature. World J Surg Oncol 2012; 10:19. [PMID: 22269186 PMCID: PMC3317839 DOI: 10.1186/1477-7819-10-19] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Accepted: 01/23/2012] [Indexed: 12/17/2022] Open
Abstract
Background Overdiagnosis of bronchopulmonary carcinoid tumors together with overtreatment can cause serious postoperative consequences for the patient. We report of a patient with a typical bronchopulmonary carcinoid tumor, which was initially misdiagnosed and treated as an adenocarcinoma of the lung. GnrH receptors and the associated Raf-1/MEK/ERK-1/2-pathway are potential targets for analogs in cancer treatment. We suspected a correlation between the lack of tumor growth, application of leuprolide and the Raf-1/MEK/ERK-1/2-pathway. Therefore, we examined GnrH receptor status in the examined specimen. Case presentation In 2010 a 77 year-old male patient was shown to have a tumor mass of about 1.7 cm diameter in the inferior lobe of the left lung. Since 2005, this tumor had hitherto been known and showed no progression in size. The patient suffered from prostate cancer 4 years ago and was treated with TUR-P, radiation therapy and the application of leuprolide. We conducted an explorative thoracotomy with atypical segment resection. The first histological diagnosis was a metastasis of prostate cancer with lymphangiosis carcinomatosa. After several immunohistochemical stainings, the diagnosis was changed to adenocarcinoma of the lung. We conducted a re-thoracotomy with lobectomy and systematic lymphadenectomy 12 days later. The tumor stage was pT1 N0 MX G2 L1 V0 R0. Further immunohistochemical studies were performed. We received the results 15 days after the last operation. The diagnosis was ultimately changed to typical carcinoid tumor without any signs of lymphatic vessel invasion. The patient recovered well from surgery, but still suffers from dyspnea and lack of physical performance. Lung function testing revealed no evidence of impairment. Conclusion The use of several immunohistochemical markers, careful evaluation of hematoxylin-eosin sections and the Ki-67 labelling index are important tools in discriminating between carcinoids and other bronchopulmonary carcinomas. Although we could not detect GnrH-receptors in the examined specimen, there may be individual differences in expression. GnrH receptor profiles in typical and atypical carcinoids should be scrutinized. This could lead to new therapeutical options, since the GnrH receptor has already been described on atypical carcinoids. Clinically tested drugs such as leuprolide could come to use.
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Affiliation(s)
- Ilhan Demirci
- Department of General, Visceral, Vascular and Thoracic Surgery, Hospital of Düren.
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20
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Ramsden N, Perrin J, Ren Z, Lee BD, Zinn N, Dawson VL, Tam D, Bova M, Lang M, Drewes G, Bantscheff M, Bard F, Dawson TM, Hopf C. Chemoproteomics-based design of potent LRRK2-selective lead compounds that attenuate Parkinson's disease-related toxicity in human neurons. ACS Chem Biol 2011; 6:1021-8. [PMID: 21812418 DOI: 10.1021/cb2002413] [Citation(s) in RCA: 122] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Leucine-rich repeat kinase-2 (LRRK2) mutations are the most important cause of familial Parkinson's disease, and non-selective inhibitors are protective in rodent disease models. Because of their poor potency and selectivity, the neuroprotective mechanism of these tool compounds has remained elusive so far, and it is still unknown whether selective LRRK2 inhibition can attenuate mutant LRRK2-dependent toxicity in human neurons. Here, we employ a chemoproteomics strategy to identify potent, selective, and metabolically stable LRRK2 inhibitors. We demonstrate that CZC-25146 prevents mutant LRRK2-induced injury of cultured rodent and human neurons with mid-nanomolar potency. These precise chemical probes further validate this emerging therapeutic strategy. They will enable more detailed studies of LRRK2-dependent signaling and pathogenesis and accelerate drug discovery.
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Affiliation(s)
- Nigel Ramsden
- Cellzome Ltd., Chesterford Research Park, Cambridge CB10 1XL, United Kingdom
| | - Jessica Perrin
- Cellzome AG, Meyerhofstrasse 1, D-69117 Heidelberg, Germany
| | - Zhao Ren
- Elan Corporation PLC, 800 Gateway Boulevard, South San Francisco, California 94080, United States
| | - Byoung Dae Lee
- Institute for Cell Engineering, Neuroregeneration and Stem Cell Programs, Johns Hopkins University School of Medicine, 733 N. Broadway, Baltimore, Maryland 21205, United States
| | - Nico Zinn
- Cellzome AG, Meyerhofstrasse 1, D-69117 Heidelberg, Germany
| | - Valina L. Dawson
- Institute for Cell Engineering, Neuroregeneration and Stem Cell Programs, Johns Hopkins University School of Medicine, 733 N. Broadway, Baltimore, Maryland 21205, United States
| | - Danny Tam
- Elan Corporation PLC, 800 Gateway Boulevard, South San Francisco, California 94080, United States
| | - Michael Bova
- Elan Corporation PLC, 800 Gateway Boulevard, South San Francisco, California 94080, United States
| | - Manja Lang
- Cellzome AG, Meyerhofstrasse 1, D-69117 Heidelberg, Germany
| | - Gerard Drewes
- Cellzome AG, Meyerhofstrasse 1, D-69117 Heidelberg, Germany
| | | | - Frederique Bard
- Elan Corporation PLC, 800 Gateway Boulevard, South San Francisco, California 94080, United States
| | - Ted M. Dawson
- Institute for Cell Engineering, Neuroregeneration and Stem Cell Programs, Johns Hopkins University School of Medicine, 733 N. Broadway, Baltimore, Maryland 21205, United States
| | - Carsten Hopf
- Cellzome AG, Meyerhofstrasse 1, D-69117 Heidelberg, Germany
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21
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Cakir M, Grossman A. The molecular pathogenesis and management of bronchial carcinoids. Expert Opin Ther Targets 2011; 15:457-91. [DOI: 10.1517/14728222.2011.555403] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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Abstract
Although neuroendocrine tumors are rare, the more common types such as gastrointestinal and pancreatic carcinoids, medullary thyroid cancers, and small cell lung cancers have been studied in detail during the last few years. Data published thus far indicate that multiple signaling pathways are involved in these cancers. Recent focus has been on developing novel therapeutics by targeting specific signaling pathways. This article details several of the signaling mechanisms that have been discovered to play a role in the development and progression of neuroendocrine tumors. The therapeutic options developed to address the various pathways, including their specific mechanisms of actions, are also discussed.
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Affiliation(s)
- Barbara Zarebczan
- Endocrine Surgery Research Laboratories, Department of Surgery, University of Wisconsin Carbone Cancer Center, Madison, WI 53705, USA
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23
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Chen H, Sippel RS, O'Dorisio MS, Vinik AI, Lloyd RV, Pacak K. The North American Neuroendocrine Tumor Society consensus guideline for the diagnosis and management of neuroendocrine tumors: pheochromocytoma, paraganglioma, and medullary thyroid cancer. Pancreas 2010; 39:775-83. [PMID: 20664475 PMCID: PMC3419007 DOI: 10.1097/mpa.0b013e3181ebb4f0] [Citation(s) in RCA: 370] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Pheochromocytomas, intra-adrenal paraganglioma, and extra-adrenal sympathetic and parasympathetic paragangliomas are neuroendocrine tumors derived from adrenal chromaffin cells or similar cells in extra-adrenal sympathetic and parasympathetic paraganglia, respectively. Serious morbidity and mortality rates associated with these tumors are related to the potent effects of catecholamines on various organs, especially those of the cardiovascular system. Before any surgical procedure is done, preoperative blockade is necessary to protect the patient against significant release of catecholamines due to anesthesia and surgical manipulation of the tumor. Treatment options vary with the extent of the disease, with laparoscopic surgery being the preferred treatment for removal of primary tumors. Medullary thyroid cancer (MTC) is a malignancy of the thyroid C cells or parafollicular cells. Thyroid C cells elaborate a number of peptides and hormones, such as calcitonin, carcinoembryonic antigen, and chromogranin A. Some or all of these markers are elevated in patients with MTC and can be used to confirm the diagnosis as well as to follow patients longitudinally for recurrence. Medullary thyroid cancer consists of a spectrum of diseases that ranges from extremely indolent tumors that are stable for many years to aggressive types associated with a high mortality rate. Genetic testing for RET mutations has allowed identification of familial cases and prophylactic thyroidectomy for cure. The only curative treatment is complete surgical resection.
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Affiliation(s)
- Herbert Chen
- Department of Surgery, University of Wisconsin, Madison, WI 53792-7375, USA.
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Carnahan J, Beltran PJ, Babij C, Le Q, Rose MJ, Vonderfecht S, Kim JL, Smith AL, Nagapudi K, Broome MA, Fernando M, Kha H, Belmontes B, Radinsky R, Kendall R, Burgess TL. Selective and potent Raf inhibitors paradoxically stimulate normal cell proliferation and tumor growth. Mol Cancer Ther 2010; 9:2399-410. [PMID: 20663930 DOI: 10.1158/1535-7163.mct-10-0181] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Raf inhibitors are under clinical investigation, specifically in patients with tumor types harboring frequent activating mutations in B-Raf. Here, we show that cell lines and tumors harboring mutant B-Raf were sensitive to a novel series of Raf inhibitors (e.g., (V600E)B-Raf A375, IC(50) on cells = 2 nmol/L; ED(50) on tumor xenografts = 1.3 mg/kg). However, in cells and tumors with wild-type B-Raf, exposure to Raf inhibitors resulted in a dose-dependent and sustained activation of mitogen-activated protein kinase signaling. In some of these cell lines, Raf inhibition led to entry into the cell cycle, enhanced proliferation, and significantly stimulated tumor growth in vivo. Inhibition with structurally distinct Raf inhibitors or isoform-specific small interfering RNA knockdown of Raf showed that these effects were mediated directly through Raf. Either A-Raf or C-Raf mediated the Raf inhibitor-induced mitogen-activated protein kinase pathway activation in an inhibitor-specific manner. These paradoxical effects of Raf inhibition were seen in malignant and normal cells in vitro and in vivo. Hyperplasia of normal epithelial cells in the esophagus and the stomach was evident in mice with all efficacious Raf inhibitors (n = 8) tested. An implication of these results is that Raf inhibitors may induce unexpected normal cell and tumor tissue proliferation in patients.
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Affiliation(s)
- Josette Carnahan
- Department of Hematology, Amgen, Inc., One Amgen Center Drive, Thousand Oaks, CA 91320, USA.
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Cook MR, Pinchot SN, Jaskula-Sztul R, Luo J, Kunnimalaiyaan M, Chen H. Identification of a novel Raf-1 pathway activator that inhibits gastrointestinal carcinoid cell growth. Mol Cancer Ther 2010; 9:429-37. [PMID: 20103603 DOI: 10.1158/1535-7163.mct-09-0718] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Carcinoids are neuroendocrine tumors (NET) that secrete hormones, including serotonin, resulting in the malignant carcinoid syndrome. In addition to the significant morbidity associated with the syndrome, carcinoids are frequently metastatic at diagnosis, and untreated mortality at 5 years exceeds 70%. Surgery is the only curative option, and the need for other therapies is clear. We have previously shown that activation of Raf-1 inhibits carcinoid cell proliferation. We investigated the ability of leflunomide (LFN), a Food and Drug Administration-approved medication for the treatment of rheumatoid arthritis, and its active metabolite teriflunomide (TFN) as a potential anti-NET treatment. LFN and TFN inhibit the in vitro proliferation of gastrointestinal carcinoid cells and induce G(2)-M phase arrest. Daily oral gavage of nude mice with subcutaneous xenografted carcinoid tumors confirms that LFN can inhibit NET growth in vivo. Treatment with TFN suppresses the cellular levels of serotonin and chromogranin A, a glycopeptide co-secreted with bioactive hormones. Additionally, TFN reduces the level of achaete-scute complex-like 1 (ASCL1), a NET marker correlated with survival. These effects are associated with the activation of the Raf-1/mitiogen-activated protein kinase kinase/extracellular signal-regulated kinase-1/2 pathway, and blockade of mitiogen-activated protein kinase kinase signaling reversed the effects of TFN on markers of the cell cycle and ASCL1 expression. In summary, LFN and TFN inhibit carcinoid cell proliferation in vitro and in vivo and alter the expression of NET markers. This compound thus represents an attractive target for further clinical investigation.
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Affiliation(s)
- Mackenzie R Cook
- Endocrine Surgery Research Laboratory, University of Wisconsin, and the University of Wisconsin Carbone Cancer Center, Madison, Wisconsin, USA
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Rose SL, Kunnimalaiyaan M, Drenzek J, Seiler N. Notch 1 signaling is active in ovarian cancer. Gynecol Oncol 2010; 117:130-3. [PMID: 20060575 DOI: 10.1016/j.ygyno.2009.12.003] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2009] [Revised: 11/25/2009] [Accepted: 12/02/2009] [Indexed: 11/17/2022]
Abstract
OBJECTIVE.: Despite advances in chemotherapy and radical surgery, most advanced stage ovarian cancer patients die from their disease, highlighting the need for the development of novel treatment strategies. The Notch signaling pathway plays an important role in cellular differentiation, proliferation and apoptosis. We hypothesized that the active form of Notch 1, the Notch 1 intracellular domain (NICD), would be overexpressed in ovarian cancer cells and that depletion of NICD would lead to growth reduction. METHODS.: Following institutional review board approval, NICD expression was analyzed in human ovarian cancer specimens as well as the ovarian cancer cell lines OVCAR3, SKOV3, and CaOV3. In addition, the effects of Notch 1 depletion on ovarian cancer cell growth were detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) growth assay for 6 days following transfection with siRNA against Notch 1. RESULTS.: Western blot analysis revealed abundant NICD expression in all 3 ovarian cancer cell lines, as well as in 16 of 21 (76%) human ovarian cancer samples. Following treatment with Notch 1 siRNA, expression of NICD was greatly reduced in all three cell lines. Furthermore, this depletion of NICD was associated with significant growth inhibition of all three ovarian cancer cell lines. CONCLUSIONS.: NICD was frequently expressed in ovarian cancer cell lines and human ovarian cancer specimens. Importantly, depletion of Notch 1 led to growth inhibition of ovarian cancer cells. These findings support the hypothesis that Notch 1 plays a role in ovarian cancer proliferation, encouraging the investigation of this pathway as a therapeutic target.
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Affiliation(s)
- Stephen L Rose
- The Department of Obstetrics and Gynecology, The University of Wisconsin, Madison, WI 53792, USA.
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Chen JY, Cook MR, Pinchot SN, Kunnimalaiyaan M, Chen H. MG-132 inhibits carcinoid growth and alters the neuroendocrine phenotype. J Surg Res 2010; 158:15-9. [PMID: 19765735 DOI: 10.1016/j.jss.2009.05.032] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2009] [Revised: 05/14/2009] [Accepted: 05/15/2009] [Indexed: 12/28/2022]
Abstract
BACKGROUND Carcinoid cancers are the most common neuroendocrine (NE) tumors, and limited treatment options exist. The inhibition of glycogen synthase kinase-3beta (GSK-3beta) has been shown to be a potential therapeutic target for the treatment of carcinoid disease. In this study, we investigate the ability of MG-132, a proteasome inhibitor, to inhibit carcinoid growth, the neuroendocrine phenotype, and its association with GSK-3beta. MATERIALS AND METHODS Human pulmonary (NCI-H727) and gastrointestinal (BON) carcinoid cells were treated with MG-132 (0-4microM). Cellular growth was measured by the 3-[4,5-dimethylthiazole-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay. Levels of total and phosphorylated GSK-3beta and the NE markers chromogranin A (CgA), Achaete-Scute complex-like 1 (ASCL1), as well as the apoptotic markers poly (ADP-ribose), polymerase (PARP), and cleaved caspase-3 were determined by Western blot. RESULTS Treating carcinoid cells with MG-132 resulted in growth inhibition, a dose-dependent inhibition of CgA and ASCL1, as well as an increase in the levels of cleaved PARP and cleaved caspase-3. Additionally, an increase in the level of phosphorylated GSK-3beta was observed. CONCLUSION MG-132 inhibits cellular growth and the neuroendocrine phenotype. This proteasome inhibitor warrants further preclinical investigation as a possible therapeutic strategy for intractable carcinoid disease.
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Affiliation(s)
- Jui-yu Chen
- Endocrine Surgery Research Laboratories, Department of Surgery, University of Wisconsin, Madison, Wisconsin 53792, USA.
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Medullary thyroid carcinoma: targeted therapies and future directions. JOURNAL OF ONCOLOGY 2009; 2009:183031. [PMID: 20069043 PMCID: PMC2798103 DOI: 10.1155/2009/183031] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 02/28/2009] [Accepted: 11/24/2009] [Indexed: 12/12/2022]
Abstract
Medullary thyroid cancer (MTC) is a rare neuroendocrine neoplasm that accounts for approximately 5% of all thyroid malignancies. The natural history of MTC is characterized by early lymph node and distant metastases, making complete surgical cure often impossible. Conventional chemotherapy and external beam radiation have been largely ineffective in altering the natural history of MTC. Therefore, there is a great need to develop novel therapeutic strategies to affect symptom control and reduce tumor burden in patients with widely disseminated disease. Here, we review several pathways which have been shown to be vital in MTC tumorigenesis and focus on the pathways of interest for which targeted drug therapies are currently being developed.
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Capurso G, Fazio N, Festa S, Panzuto F, De Braud F, Delle Fave G. Molecular target therapy for gastroenteropancreatic endocrine tumours: Biological rationale and clinical perspectives. Crit Rev Oncol Hematol 2009; 72:110-24. [DOI: 10.1016/j.critrevonc.2009.01.008] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2008] [Revised: 01/13/2009] [Accepted: 01/28/2009] [Indexed: 02/08/2023] Open
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Deming D, Geiger P, Chen H, Kunnimalaiyaan M, Holen K. ZM336372 induces apoptosis associated with phosphorylation of GSK-3beta in pancreatic adenocarcinoma cell lines. J Surg Res 2009; 161:28-32. [PMID: 20031160 DOI: 10.1016/j.jss.2009.06.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2009] [Revised: 05/28/2009] [Accepted: 06/09/2009] [Indexed: 12/30/2022]
Abstract
INTRODUCTION ZM336372 is small molecule tyrosine kinase modulator. It has been shown to inhibit glycogen synthase kinase-3beta (GSK-3beta) through phosphorylation of GSK-3beta at Ser 9. GSK-3beta has previously been shown to mediate cell survival in pancreatic cancer cells. Here we determine the effects of ZM336372 on GSK-3beta phosphorylation, apoptosis, and growth in pancreatic adenocarcinoma cell lines. METHODS Panc-1 and MiaPaCa-2 cells were treated with ZM336372 or lithium chloride (LiCl) and compared with solvent control. The effects on proliferation for each cell line were determined using the MTT assay. Western blot analysis was performed to examine the effects of treatment on the phosphorylation of GSK-3beta. In addition, western blot was utilized to examine the cleavage of poly (ADP-ribose) polymerase (PARP), a marker of apoptosis. RESULTS A dose-dependent increase in phosphorylation of GSK-3beta was observed after treatment with both ZM336372 and LiCl. Growth inhibition due to treatment with ZM336372 and LiCl also occurred in a dose-dependent fashion. An increase in cleaved PARP was demonstrated after treatment with both agents, as was seen previously with GSK-3beta inhibition in pancreatic adenocarcinoma cells. CONCLUSION This is the first description of growth inhibition and apoptosis in pancreatic cancer cells related to GSK-3beta inhibition through treatment with ZM336372.
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Affiliation(s)
- Dustin Deming
- Department of Medicine, University of Wisconsin, Madison, Wisconsin 53792, USA
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Pitt SC, Chen H, Kunnimalaiyaan M. Inhibition of phosphatidylinositol 3-kinase/Akt signaling suppresses tumor cell proliferation and neuroendocrine marker expression in GI carcinoid tumors. Ann Surg Oncol 2009; 16:2936-42. [PMID: 19588205 DOI: 10.1245/s10434-009-0591-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2008] [Revised: 06/11/2009] [Accepted: 06/11/2009] [Indexed: 11/18/2022]
Abstract
BACKGROUND Overactivation of PI3K/Akt signaling facilitates tumor proliferation in several cancers. We have shown that various signal transduction pathways promote tumorigenesis in carcinoid tumors, which exhibit endogenously high levels of active, phosphorylated Akt. Therefore, we hypothesized that inhibition of the PI3K/Akt pathway would suppress carcinoid tumor cell growth and neuroendocrine (NE) marker production. METHODS Human carcinoid BON cells were treated in vitro with LY294002, a PI3-kinase inhibitor, or transfected with Akt1 siRNA. Tumor cell proliferation was measured by MTT for 6 days. The effect of LY294002 or Akt1 siRNA treatment was assessed by Western analysis. We examined the levels of phosphorylated Akt, total Akt, Akt1, and the NE markers human achaete-scute homolog1 (ASCL1) and chromogranin A (CgA). RESULTS Treatment of BON cells with LY294002 reduced tumor cell proliferation (76%) in a dose-dependent manner. Growth also decreased in Akt1 siRNA transfected cells (26%). Levels of active, phosphorylated Akt and the NE tumor markers, ASCL1 and CgA, were diminished with both LY294002 and Akt1 siRNA treatments proportional to the degree of Akt inhibition. Total Akt, Akt2, and Akt3 levels were unaffected by these experiments. CONCLUSIONS These data indicate that PI3K/Akt signaling performs a critical role in human carcinoid tumor cell survival and NE hormone generation. Furthermore, the development of novel therapeutics targeting Akt1 or components of the PI3K/Akt pathway may enhance the management of carcinoid disease.
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Affiliation(s)
- Susan C Pitt
- Endocrine Surgery Research Laboratory, Department of Surgery, University of Wisconsin, Madison, WI, USA
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Stoll SJ, Pitt SC, Chen H. Follicular thyroid cancer cell growth inhibition by proteosome inhibitor MG132. J Surg Res 2009; 156:39-44. [PMID: 19552924 DOI: 10.1016/j.jss.2009.03.070] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2008] [Revised: 02/24/2009] [Accepted: 03/23/2009] [Indexed: 11/25/2022]
Abstract
BACKGROUND Effective therapies for the subset of follicular thyroid cancer (FTC) patients with aggressive, metastatic disease are lacking. Therefore, we sought to determine the effects of proteosome inhibition, an emerging class of chemotherapeutic agents, on metastatic FTC cells. MATERIALS AND METHODS Human metastatic FTC cells (FTC236) were treated in vitro with the proteosome inhibitor MG132 (0 to 800 nM). Western blot analysis was performed on whole cell lysates isolated after 2 d. To measure cell growth, we performed an MTT cellular proliferation assay over 6 d. RESULTS Treatment of FTC236 cells with MG132 led to dose-dependent cell growth inhibition. Increases in inactive, phosphorylated GSK-3beta, and active beta-catenin also were observed. With 800 nM MG132, growth was reduced by 87% at 6 d (P < 0.0001). This reduction in cellular proliferation correlated with the degree of GSK-3beta inhibition. MG132 treatment also caused increased p21(Waf1/Cip1) and decreased cyclin D1 expression, suggesting that growth suppression may occur through cell cycle arrest. CONCLUSION Growth of metastatic human FTC cells appears to be suppressed by proteosome inhibition. Whether this effect is directly due to cell cycle arrest and inactivation of GSK-3beta signaling is unclear. Nonetheless, these compounds may become novel treatments for aggressive, metastatic FTC.
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Affiliation(s)
- Samantha J Stoll
- Endocrine Surgery Research Laboratory, Department of Surgery, University of Wisconsin, Madison, WI 53792-3284, USA
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Phosphatidylinositol 3-kinase-Akt signaling in pulmonary carcinoid cells. J Am Coll Surg 2009; 209:82-8. [PMID: 19651067 DOI: 10.1016/j.jamcollsurg.2009.03.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2008] [Revised: 03/10/2009] [Accepted: 03/11/2009] [Indexed: 11/20/2022]
Abstract
BACKGROUND In several types of cancer, upregulation of phosphatidylinositol 3-kinase (PI3K)-Akt signaling facilitates tumor cell growth and inhibits apoptosis. Previous reports demonstrated that this pathway promotes growth, survival, and chemotherapy resistance in non-small cell and small cell lung cancer cells. But the importance of PI3K-Akt signaling has not been explored in pulmonary carcinoids. In this study, our objective was to establish the role of the PI3K-Akt signal transduction pathway in pulmonary carcinoid cells. STUDY DESIGN Human pulmonary carcinoid NCI-H727 cells were treated with LY294002 (0 to 100 microM), a well-known PI3K inhibitor, or transfected with Akt1 small interfering RNA (75 nM). Cellular proliferation was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay for up to 8 days. Western blot analysis was performed for expression of active, phosphorylated Akt (pAkt), total Akt, Akt1, and the neuroendocrine markers chromogranin A and achaete-scute complex-like1. RESULTS Treatment of NCI-H727 cells with LY294002 significantly reduced tumor cell growth (85.3%). Similarly, Akt1 small interfering RNA transfection led to diminished tumor cell proliferation (31.3%). A dose-dependent decrease in chromogranin A and achaete-scute complex-like1 production was observed with both PI3K inhibition and Akt1 RNA interference. Expression of Akt1 was reduced at all time points by transient Akt1 small interfering RNA transfection. CONCLUSIONS The PI3K-Akt pathway plays a role in both tumor cell growth and neuroendocrine hormone secretion in human pulmonary carcinoid cells. Inhibition of Akt1, PI3K-Akt signaling, or a downstream mediator of this pathway may provide therapeutic approaches for patients with pulmonary carcinoid tumors.
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Pinchot SN, Adler JT, Luo Y, Ju J, Li W, Shen B, Kunnimalaiyaan M, Chen H. Tautomycin suppresses growth and neuroendocrine hormone markers in carcinoid cells through activation of the Raf-1 pathway. Am J Surg 2009; 197:313-9. [PMID: 19245907 DOI: 10.1016/j.amjsurg.2008.10.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2008] [Revised: 10/31/2008] [Accepted: 10/31/2008] [Indexed: 11/24/2022]
Abstract
BACKGROUND Carcinoids are neuroendocrine (NE) tumors with limited treatment options. Raf-1 pathway activation has been shown to suppress hormone production in carcinoid cells. We investigated a novel treatment for carcinoid cell growth based on pharmacologic Raf-1 activation using the compound tautomycin (TTY). METHODS Human carcinoid cells were treated with TTY for 48 hours. Western blot analysis was used to demonstrate Raf-1 pathway activation by phosphorylation of ERK1/2 and to determine the effect on NE tumor markers. Cellular growth was measured by methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay. RESULTS Treatment with TTY resulted in dose-dependent activation of the Raf-1 pathway. Furthermore, a significant decrease in NE tumor markers was seen. Importantly, TTY inhibited carcinoid cellular growth and induced the cell-cycle inhibitors p21 and p27. CONCLUSION TTY activates the Raf-1 pathway, limits carcinoid cell growth, and suppresses NE marker production in vitro. This new compound warrants further investigation in animal models of carcinoid cancer.
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Affiliation(s)
- Scott N Pinchot
- Endocrine Surgery Research Laboratories, Department of Surgery, University of Wisconsin, Madison, WI, USA
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Abstract
Carcinoid tumors are rare, slow-growing neuroendocrine tumors arising from the enterochromaffin cells disseminated throughout the gastrointestinal and bronchopulmonary systems. Though they have been traditionally classified based on embryologic site of origin, morphologic pattern, and silver affinity, newer classification systems have been developed to emphasize the considerable clinical and histopathologic variability of carcinoid tumors found within each embryologic site of origin. These neoplasms pose a diagnostic challenge because they are often innocuous at the time of presentation, emphasizing the need for a multidisciplinary diagnostic approach using biochemical analysis, standard cross-sectional imaging, and newer advances in nuclear medicine. Similarly, treatment of both primary and disseminated carcinoid disease reflects the need for a multidisciplinary approach, with surgery remaining the only curative modality. The prognosis for patients with these tumors is generally favorable; however, it can be quite variable and is related to the location of the primary tumor, extent of metastatic disease at initial presentation, and time of diagnosis.
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Affiliation(s)
- Scott N Pinchot
- Section of Endocrine Surgery, Department of Surgery, University of Wisconsin, Madison, WI 53792, USA
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Adler JT, Hottinger DG, Kunnimalaiyaan M, Chen H. Combination therapy with histone deacetylase inhibitors and lithium chloride: a novel treatment for carcinoid tumors. Ann Surg Oncol 2008; 16:481-6. [PMID: 19030935 DOI: 10.1245/s10434-008-0194-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2008] [Revised: 09/14/2008] [Accepted: 09/15/2008] [Indexed: 12/17/2022]
Abstract
In carcinoid cell lines, the histone deacetylase (HDAC) inhibitors valproic acid (VPA) and suberoyl bis-hydroxamic acid (SBHA) activate the Notch1 pathway, whereas lithium inhibits glycogen synthase kinase-3beta (GSK-3beta). These compounds limit growth and decrease hormonal secretion in vitro. We hypothesized that lower-dose combination therapy of HDAC inhibitors and lithium chloride could achieve similar growth inhibition to that of the drugs alone. Gastrointestinal and pulmonary carcinoid cells were treated with either VPA or SBHA and lithium chloride for up to 48 hours. Western blot analysis was used to measure the effects on the Notch1 and GSK-3beta pathways and the neuroendocrine tumor marker chromogranin A (CgA). Growth was measured by a cellular proliferation assay. With lower-dose combination therapy, a decrease in CgA was observed. The HDAC inhibitors increased the amount of active Notch1 protein, whereas treatment with lithium was associated with inhibition of GSK-3beta. Moreover, growth was inhibited with lower-dose combination therapy. Treatment of carcinoid cells with either VPA or SBHA and lithium chloride suppresses the neuroendocrine marker CgA while upregulating Notch1 and inhibiting GSK-3beta. This combination effectively reduces growth. Thus, lower-dose combination therapy may be a viable therapeutic approach for carcinoid tumors.
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Affiliation(s)
- Joel T Adler
- Department of Surgery, University of Wisconsin, Clinical Science Center, Madison, 53792, USA
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Valproic acid activates Notch1 signaling and induces apoptosis in medullary thyroid cancer cells. Ann Surg 2008; 247:1036-40. [PMID: 18520232 DOI: 10.1097/sla.0b013e3181758d0e] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To examine the effects of valproic acid (VPA) on Notch1 expression and cancer cell proliferation in medullary thyroid cancer (MTC) cells. BACKGROUND Other than surgery, there are no effective treatments for MTC, a neuroendocrine malignancy that frequently metastasizes. We have previously shown that over-expression of Notch1 in MTC cells inhibits cell growth and hormone production. VPA, a drug long used for the treatment of epilepsy, has recently been identified as a potential Notch1 activator. We hypothesized that VPA might activate Notch1 signaling in MTC cells, with antiproliferative effects. METHODS Human MTC cells were treated with VPA (0-5 mM) and Western blotting was performed to measure levels of Notch1 pathway proteins and neuroendocrine tumor markers. After confirming that VPA is a Notch1 activator in MTC cells, we performed cell proliferation assay. Finally, to determine the mechanism of growth inhibition, we measured protein levels of various markers of apoptosis. RESULTS Notch1 was absent in MTC cells at baseline. VPA treatment resulted in an increase in both full-length and active Notch1 protein. Notch1 activation with VPA suppressed 2 neuroendocrine tumor markers, ASCL1 and chromogranin A. Importantly, VPA inhibited the growth of MTC cells in a dose-dependent manner. Immunoblot analysis demonstrated caspase activation and poly(ADP-ribose) polymerase cleavage, indicating the induction of apoptosis. CONCLUSIONS VPA activates Notch1 signaling in MTC cells and inhibits their growth by inducing apoptosis. As the safety of VPA in human beings is well established, a clinical trial using this drug to treat patients with advanced MTC could be initiated in the near future.
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Deming D, Geiger P, Chen H, Vaccaro A, Kunnimalaiyaan M, Holen K. ZM336372, a Raf-1 activator, causes suppression of proliferation in a human hepatocellular carcinoma cell line. J Gastrointest Surg 2008; 12:852-7. [PMID: 18299943 DOI: 10.1007/s11605-008-0495-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Hepatocellular carcinoma has been described to exhibit characteristics similar to that of neuroendocrine tumors (NETs). This includes similar anti-neoplastic responses to extracellular signal-regulated kinase (ERK) activation. NET cells and HepG2 cells have both shown growth inhibition with ERK activation. ZM336372, a Raf-1 activating agent, has been shown to cause growth inhibition and suppression of hormone secretion in a neuroendocrine cell line. Here we examine treatment of the HepG2 cell line with ZM336732 to determine if a similar anti-proliferative response will be obtained. HepG2 cells were treated with ZM336372 or solvent (dimethyl sulfoxide). The resulting effect on the proliferation was measured using the 3,4-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Western blot analysis was performed to examine the activation of the Raf-1/mitogen-activated protein kinase kinase/ERK pathway, chromogranin A production, and p21CIP1 level. Growth inhibition was observed with ZM336372 in a dose-dependent fashion. Minimal baseline phosphorylation of ERK 1/2 was observed; however, activation was observed after treatment with ZM336372. Chromogranin A secretion was suppressed due to treatment with ZM336372. A dose-dependent up-regulation of p21CIP1 was observed in response to ZM336372 treatment. ZM336372 causes growth inhibition, suppression of hormone secretion, and up-regulation of cell cycle inhibitors in a human hepatocellular carcinoma cell line, similar to that previously seen in NETs.
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Affiliation(s)
- Dustin Deming
- Department of Medicine, University of Wisconsin, K4/528, Madison, WI 53792, USA
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Kunnimalaiyaan M, Ndiaye M, Chen H. Neuroendocrine tumor cell growth inhibition by ZM336372 through alterations in multiple signaling pathways. Surgery 2008; 142:959-64; discussion 959-64. [PMID: 18063082 DOI: 10.1016/j.surg.2007.09.020] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2007] [Revised: 09/06/2007] [Accepted: 09/11/2007] [Indexed: 10/22/2022]
Abstract
BACKGROUND We have shown previously that activation of the Raf-1/mitogen-activated protein kinase (MEK)/extracellular signal-regulated kinase (ERK)1/2 signaling pathway by ZM336372 inhibits carcinoid cells growth. In the present study, we further characterize the molecular details of the growth inhibition by the signaling-based compound ZM336372 in neuroendocrine neoplasms (NENs). METHODS NEN cells were treated with ZM336372 (20 to 100 mumol/L) or carrier (DMSO). Western Blot was used to determine the activation of the Raf-1/MEK/ERK, other pathways activation, and cellular bioactive hormone production. RESULTS ZM336372 in NEN cells resulted in increasing raf-1 activation and inactivation of glycogen synthase kinase-3 beta (GSK-3beta) as measured by phosphorylation of ERK1/2 and GSK-3beta, respectively. There was no alteration in the levels of phosphorylated Akt, an important mediator of the phosphatidyl inositol 3 kinase pathway. Importantly, blocking of raf-1 pathway by U0126, a potent inhibitor, in the presence of ZM336372 did not reduce the levels of p-GSK-3beta, indicating that GSK-3beta inactivation is independent of raf-1 pathway activation. Moreover, the levels of chromogranin A and achaete-scute complex like-1 reductions were persistent even after blocking the raf-1 pathway. Treatment with ZM336372 in the presence of small interfering RNA against raf-1 resulted in an increase in Raf-1 production, suggesting that ZM336372 upregulates raf-1 at the transcriptional level. CONCLUSION This is the first description of a novel compound ZM336372 that regulates multiple pathways in NEN cells.
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Affiliation(s)
- Muthusamy Kunnimalaiyaan
- Endocrine Surgery Research Laboratories, Section of Endocrine Surgery, Department of Surgery, Madison, Wisconsin, USA.
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Abstract
Over the past 5 years, the Raf kinase family has emerged as a promising target for protein-directed cancer therapy development. The goal of this review is to first provide a concise summary of the data validating Raf proteins as high-interest therapeutic targets. The authors then outline the mode of action of Raf kinases, emphasizing how Raf activities and protein interactions suggest specific approaches to inhibiting Raf. The authors then summarize the set of drugs, antisense reagents and antibodies available or in development for therapeutically targeting Raf or Raf-related proteins, as well as existing strategies combining these and other therapeutic agents. Finally, the authors discuss recent results from systems biology analyses that have the potential to increasingly guide the intelligent selection of combination therapies involving Raf-targeting agents and other therapeutics.
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Greenblatt DY, Cayo M, Ning L, Jaskula-Sztul R, Haymart M, Kunnimalaiyaan M, Chen H. Suberoyl bishydroxamic acid inhibits cellular proliferation by inducing cell cycle arrest in carcinoid cancer cells. J Gastrointest Surg 2007; 11:1515-20; discussion 1520. [PMID: 17874277 DOI: 10.1007/s11605-007-0249-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2007] [Accepted: 07/17/2007] [Indexed: 01/31/2023]
Abstract
Carcinoid cancers arise from the neuroendocrine cell system of the gastrointestinal tract, lungs, and other organs. Hepatic metastases are common, and patients often suffer from endocrinopathies secondary to tumor secretion of various hormones and peptides. As complete surgical resection is often not possible because of widespread disease, new therapeutic and palliative treatments are needed. In this study, we characterized the effects of suberoyl bishydroxamic acid (SBHA), a histone deacetylase inhibitor, on the growth and neuroendocrine phenotype of carcinoid cancer cells. SBHA treatment of human gastrointestinal and pulmonary carcinoid cancer cells resulted in a dose-dependent inhibition of cell proliferation. Western blot analysis showed a decrease in cyclin D1 and an increase in p21 and p27, indicating that the mechanism of this growth inhibition is cell cycle arrest. Furthermore, SBHA treatment suppressed two neuroendocrine tumor markers, chromogranin A and achaete-scute complex-like 1. These changes in the growth and neuroendocrine phenotype of carcinoid cells were associated with activation of the Notch1 signaling cascade. We conclude that SBHA shows promise as a potential anticancer agent for the treatment of patients with advanced carcinoid tumor disease.
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Affiliation(s)
- David Yu Greenblatt
- Endocrine Surgery Research Laboratories, Department of Surgery, University of Wisconsin, Madison, WI 53792, USA
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Greenblatt DY, Vaccaro AM, Jaskula-Sztul R, Ning L, Haymart M, Kunnimalaiyaan M, Chen H. Valproic acid activates notch-1 signaling and regulates the neuroendocrine phenotype in carcinoid cancer cells. Oncologist 2007; 12:942-51. [PMID: 17766653 DOI: 10.1634/theoncologist.12-8-942] [Citation(s) in RCA: 112] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Carcinoid tumors are neuroendocrine malignancies that frequently metastasize and secrete hormones that cause debilitating symptoms in patients. In this study we report the effects of valproic acid (VPA), a drug long used for the treatment of epilepsy, on the growth and neuroendocrine phenotype of human carcinoid cancer cells. VPA treatment of gastrointestinal and pulmonary carcinoid cells resulted in a dose-dependent inhibition of cancer cell growth. Western blot analysis revealed degradation of cyclin D1 and an increase in cyclin-dependent kinases p21 and p27 with VPA treatment. Flow cytometry confirmed that the mechanism of VPA-induced growth inhibition is G(1) phase cell cycle arrest. Furthermore, VPA suppressed expression of the neuroendocrine tumor marker chromogranin A. In addition to these effects, VPA also increased levels of full-length Notch-1 and the active Notch-1 intracellular domain. Luciferase reporter assays incorporating the centromere-binding factor 1 (CBF-1) binding site and the achaete-scute complex-like 1 (ASCL-1) promoter confirmed the functional activity of VPA-induced Notch-1. Transfection of Notch-1 small-interfering RNA into carcinoid tumor cells blocked the effects of VPA on Notch-1 activation, ASCL-1 suppression, p21 induction, and cell growth inhibition. VPA also suppressed growth of carcinoid tumors in vivo in a mouse tumor xenograft experiment. These findings confirm the important role of Notch-1 in regulating the growth and neuroendocrine phenotype of carcinoid tumor cells. On the basis of this study, a clinical trial of VPA for patients with advanced carcinoid cancer will be conducted. Disclosure of potential conflicts of interest is found at the end of this article.
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Affiliation(s)
- David Yu Greenblatt
- F.A.C.S., H4/750 Clinical Science Center, 600 Highland Avenue, Madison, Wisconsin 53792, USA
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Lemos B, Nghiem P. Merkel cell carcinoma: more deaths but still no pathway to blame. J Invest Dermatol 2007; 127:2100-3. [PMID: 17700621 DOI: 10.1038/sj.jid.5700925] [Citation(s) in RCA: 170] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Merkel cell carcinoma (MCC) is a neuroendocrine skin cancer with a rising incidence (1500 U.S. cases per year) that now exceeds that of cutaneous T-cell lymphoma and a mortality (33%) exceeding that of melanoma. Despite this impact, little is known about its biology. Recent studies have shown that Ras/MAP kinase activity is absent and possibly detrimental to this cancer. This makes MCC distinct from other UV--induced skin cancers and highlights the question of what drives this malignancy.
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Affiliation(s)
- Bianca Lemos
- University of Washington Dermatology, Fred Hutchinson Cancer Research Center, Seattle Cancer Care Alliance, Seattle, Washington 98109, USA
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Nakakura EK, Venook AP, Bergsland EK. Systemic and Regional Nonsurgical Therapy—What Is the Optimal Strategy for Metastatic Neuroendocrine Cancer? Surg Oncol Clin N Am 2007; 16:639-51, x. [PMID: 17606198 DOI: 10.1016/j.soc.2007.04.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
A multidisciplinary team is essential for the optimal management of patients with metastatic neuroendocrine tumors. In this article, the systemic and regional nonsurgical therapeutic options for metastatic neuroendocrine cancers are discussed. In particular, the roles of biotherapy, chemotherapy, and hepatic artery embolization/chemoembolization are reviewed. A proposed treatment algorithm is provided with the aim of providing clinicians with a useful framework for managing these challenging patients. Finally, the rationale for promising investigational therapies is described.
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Affiliation(s)
- Eric K Nakakura
- Department of Surgery, Division of Surgical Oncology, University of California, UCSF Comprehensive Cancer Center, 1600 Divisadero Street, A-724, San Francisco, CA 94143-1932, USA
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Zhang X, Neufeld AH. Signal transduction pathways for epidermal growth factor stimulated cyclooxygenase-2 induction in astrocytes. Exp Eye Res 2007; 85:280-8. [PMID: 17604021 DOI: 10.1016/j.exer.2007.05.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2007] [Revised: 05/03/2007] [Accepted: 05/04/2007] [Indexed: 11/21/2022]
Abstract
Cyclooxygenase-2 (COX-2) derived prostaglandins (PGs) are pathophysiological mediators in various disease states. Recently, we have demonstrated the rapid, epidermal growth factor receptor (EGFR)-dependent induction of COX-2 and PGE(2) synthesis in astrocytes following optic nerve injury and in culture. We have now investigated the signal transduction pathways activated by EGFR to accomplish the expression of COX-2 in primary optic nerve astrocytes. When astrocytes were exposed to EGF, marked, rapid gene expression of COX-2 was observed. Activation of EGFR caused an increase in the phosphorylation of extracellular signal-regulated kinase (ERK), p38 MAPK (p38) and c-Jun NH (2)-terminal kinase (JNK). Furthermore, U0126, an ERK pathway inhibitor, and SB203580, a p38 MAPK inhibitor, diminished EGF-induced COX-2 expression; whereas, a JNK inhibitor did not suppress COX-2 expression by EGF. Using inhibitors of several other signaling cascades, we found that, unlike epithelial and cancer cells, NF-kappaB, PI 3-kinase/Akt and PKC were not signaling pathways for EGFR-dependent induction of COX-2 in optic nerve astrocytes. Taken together, these data suggest that ERK and p38 are key components of the intracellular signaling switch that transduces EGFR activation into COX-2 induction and PGE(2) biosynthesis in optic nerve astrocytes.
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Affiliation(s)
- Xu Zhang
- Laboratory for the Investigation of the Aging Retina, Department of Ophthalmology, Northwestern University School of Medicine, Tarry 13-753, 303 East Chicago Avenue, Chicago, IL 60611, USA
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Kunnimalaiyaan M, Vaccaro AM, Ndiaye MA, Chen H. Inactivation of glycogen synthase kinase-3β, a downstream target of the raf-1 pathway, is associated with growth suppression in medullary thyroid cancer cells. Mol Cancer Ther 2007; 6:1151-8. [PMID: 17363508 DOI: 10.1158/1535-7163.mct-06-0665] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Glycogen synthase kinase-3beta (GSK-3beta) is an important regulator of cell proliferation and survival. Conflicting observations have been reported regarding the regulation of GSK-3beta and extracellular signal-regulated kinase (ERK1/2) in cancer cells. In this study, we found that raf-1 activation in human medullary thyroid cancer cells, TT cells, resulted in phosphorylation of GSK-3beta. Inactivation of GSK-3beta in TT cells with well-known GSK-3beta inhibitors such as lithium chloride (LiCl) and SB216763 is associated with both growth suppression and a significant decrease in neuroendocrine markers such as human achaete-scute complex-like 1 and chromogranin A. Growth inhibition by GSK-3beta inactivation was found to be associated with cell cycle arrest due to an increase in the levels of cyclin-dependent kinase inhibitors such as p21, p27, and p15. Additionally, LiCl-treated TT xenograft mice had a significant reduction in tumor volume compared with those treated with control. For the first time, we show that GSK-3beta is a key downstream target of the raf-1 pathway in TT cells. Also, our results show that inactivation of GSK-3beta alone is sufficient to inhibit the growth of TT cells both in vitro and in vivo.
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Affiliation(s)
- Muthusamy Kunnimalaiyaan
- University of Wisconsin, H4/750 Clinical Science Center, 600 Highland Avenue, Madison, WI 53792, USA
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Greenblatt DY, Kunnimalaiyaan M, Chen H. Raf-1 activation in gastrointestinal carcinoid cells decreases tumor cell adhesion. Am J Surg 2007; 193:331-5; discussion 335. [PMID: 17320529 PMCID: PMC1838566 DOI: 10.1016/j.amjsurg.2006.09.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2006] [Revised: 09/20/2006] [Accepted: 09/20/2006] [Indexed: 11/18/2022]
Abstract
BACKGROUND Gastrointestinal carcinoid tumors are highly metastatic. Activation of the Raf-1 signaling pathway in carcinoid cells results in morphologic changes. These Raf-1-induced structural changes may affect cellular adhesion, thereby altering metastatic potential. METHODS An estrogen-inducible Raf-1 cell line (BON-raf) was used to study the effects of Raf-1 on cellular adhesion. Cell adhesion was measured before and after Raf-1 induction. Western blot analysis was used to confirm Raf-1 activation and measure levels of an essential adhesion regulator, beta-catenin. RESULTS Estrogen treatment of BON-raf cells resulted in Raf-1 activation and a marked decrease (68%) in cell adhesion. In the absence of Raf-1 induction, carcinoid cells expressed high levels of beta-catenin. Raf-1 activation led to decreased expression of beta-catenin. CONCLUSIONS Raf-1 induction in carcinoid cells results in a significant decrease in adhesion. Furthermore, the important adhesion regulator, beta-catenin, is decreased in activated BON-raf cells. These Raf-1-related changes in adhesion may alter the metastatic phenotype of carcinoid cells.
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Affiliation(s)
- David Yü Greenblatt
- Endocrine Surgery Research Laboratories, Section of Endocrine Surgery, Department of Surgery, University of Wisconsin, H4/750 Clinical Science Center, 600 Highland Ave., Madison, WI 53792, USA
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Kappes A, Vaccaro A, Kunnimalaiyaan M, Chen H. Lithium ions: a novel treatment for pheochromocytomas and paragangliomas. Surgery 2007; 141:161-5; discussion 165. [PMID: 17263970 PMCID: PMC1945109 DOI: 10.1016/j.surg.2006.12.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/20/2006] [Indexed: 11/28/2022]
Abstract
BACKGROUND Operative resection is the only curative treatment for patients with pheochromocytomas, paragangliomas, and other catecholamine-producing neoplasms. Activation of glycogen synthase kinase 3beta (GSK3beta) is thought to promote tumor growth and neuroendocrine (NE) peptide secretion in NE neoplasms. Thus, we hypothesized that inhibition of this signaling pathway with lithium chloride (LiCl), a well-known GSK3beta inhibitor, could be a potential therapeutic strategy to control tumor growth and hormone production. METHODS Pheochromocytoma PC-12 cells were treated with varying concentrations of LiCl (0 to 30 mM). Levels of active and inactive GSK3beta and NE peptides chromogranin A (CgA) and Mash1 were determined by Western blot. Cellular growth was measured by MTT cell-proliferation assay. RESULTS At baseline, PC-12 cells had increased active GSK3beta signaling. Treatment of PC-12 cells with increasing dosages of LiCl resulted in dose-dependent inhibition of GSK3beta. Importantly, LiCl inhibited pheochromocytoma cellular proliferation significantly. Furthermore, inhibition of GSK3beta by LiCl was associated with marked suppression of CgA and Mash1 levels. CONCLUSIONS These data suggest that GSK3beta inhibition may be a novel strategy to treat pheochromocytoma and other catecholamine-producing neoplasms.
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Affiliation(s)
- Ashley Kappes
- Department of Surgery, Endocrine Surgery Research Laboratories, Section of Endocrine Surgery, University of Wisconsin, Madison, WI 53792, USA
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Karhoff D, Sauer S, Schrader J, Arnold R, Fendrich V, Bartsch DK, Hörsch D. Rap1/B-Raf signaling is activated in neuroendocrine tumors of the digestive tract and Raf kinase inhibition constitutes a putative therapeutic target. Neuroendocrinology 2007; 85:45-53. [PMID: 17341847 DOI: 10.1159/000100508] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2006] [Accepted: 01/29/2007] [Indexed: 01/06/2023]
Abstract
OBJECTIVE Molecular pathogenesis of digestive neuroendocrine tumors (dNETs) is largely unknown. Recently, the serine-threonine kinase B-Raf was identified as an oncogene in endocrine cancer such as thyroid carcinoma. In endocrine cells, the small G-protein Rap1 stimulates mitogen-activated protein kinase (MAPK) signaling by activating B-Raf. We examined the expression of Rap1 and B-Raf in dNETs and their contribution to MAPK signaling in neuroendocrine cell lines. In addition, we explored the effect of suppressing B-Raf kinase by the recently developed inhibitor BAY43-9006 (Sorafinib) on growth, apoptosis and MAPK activation neuroendocrine cell lines. METHODS AND RESULTS Expression of Rap1 and B-Raf in dNETs (19 insulinomas, 15 carcinoid tumors and 10 gastrinomas) was examined by immunohistochemistry, which revealed that Rap1 and B-Raf were highly prevalent in the majority of dNETs. Overexpression of Rap1 and B-Raf activated MAPK extracellular dependent kinase (ERK) ERK-2 and ERK-dependent transcription factor Elk-1 in neuroendocrine cell lines Bon and INS-1. Suppression of B-Raf by BAY43-9006 inhibited growth and induced apoptosis in Bon and INS-1 cells. In addition, BAY43-9006 suppressed phosphorylation of MAPK ERK1/2 and its upstream kinase MEK1/2 in Bon and INS-1 cells. CONCLUSION These results indicate that Rap1-B-Raf signaling may contribute to pathogenesis of dNETs and provides a molecular target for treatment of dNETs.
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Affiliation(s)
- Dorothee Karhoff
- Department of Internal Medicine, Division of Gastroenterology and Endocrinology, Philipps University Marburg, Marburg, Germany
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