1
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TNK1 is a ubiquitin-binding and 14-3-3-regulated kinase that can be targeted to block tumor growth. Nat Commun 2021; 12:5337. [PMID: 34504101 PMCID: PMC8429728 DOI: 10.1038/s41467-021-25622-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 08/20/2021] [Indexed: 02/08/2023] Open
Abstract
TNK1 is a non-receptor tyrosine kinase with poorly understood biological function and regulation. Here, we identify TNK1 dependencies in primary human cancers. We also discover a MARK-mediated phosphorylation on TNK1 at S502 that promotes an interaction between TNK1 and 14-3-3, which sequesters TNK1 and inhibits its kinase activity. Conversely, the release of TNK1 from 14-3-3 allows TNK1 to cluster in ubiquitin-rich puncta and become active. Active TNK1 induces growth factor-independent proliferation of lymphoid cells in cell culture and mouse models. One unusual feature of TNK1 is a ubiquitin-association domain (UBA) on its C-terminus. Here, we characterize the TNK1 UBA, which has high affinity for poly-ubiquitin. Point mutations that disrupt ubiquitin binding inhibit TNK1 activity. These data suggest a mechanism in which TNK1 toggles between 14-3-3-bound (inactive) and ubiquitin-bound (active) states. Finally, we identify a TNK1 inhibitor, TP-5801, which shows nanomolar potency against TNK1-transformed cells and suppresses tumor growth in vivo.
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2
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Awate S, Sommers JA, Datta A, Nayak S, Bellani MA, Yang O, Dunn CA, Nicolae CM, Moldovan GL, Seidman MM, Cantor SB, Brosh RM. FANCJ compensates for RAP80 deficiency and suppresses genomic instability induced by interstrand cross-links. Nucleic Acids Res 2020; 48:9161-9180. [PMID: 32797166 DOI: 10.1093/nar/gkaa660] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 07/24/2020] [Accepted: 07/28/2020] [Indexed: 12/16/2022] Open
Abstract
FANCJ, a DNA helicase and interacting partner of the tumor suppressor BRCA1, is crucial for the repair of DNA interstrand crosslinks (ICL), a highly toxic lesion that leads to chromosomal instability and perturbs normal transcription. In diploid cells, FANCJ is believed to operate in homologous recombination (HR) repair of DNA double-strand breaks (DSB); however, its precise role and molecular mechanism is poorly understood. Moreover, compensatory mechanisms of ICL resistance when FANCJ is deficient have not been explored. In this work, we conducted a siRNA screen to identify genes of the DNA damage response/DNA repair regime that when acutely depleted sensitize FANCJ CRISPR knockout cells to a low concentration of the DNA cross-linking agent mitomycin C (MMC). One of the top hits from the screen was RAP80, a protein that recruits repair machinery to broken DNA ends and regulates DNA end-processing. Concomitant loss of FANCJ and RAP80 not only accentuates DNA damage levels in human cells but also adversely affects the cell cycle checkpoint, resulting in profound chromosomal instability. Genetic complementation experiments demonstrated that both FANCJ's catalytic activity and interaction with BRCA1 are important for ICL resistance when RAP80 is deficient. The elevated RPA and RAD51 foci in cells co-deficient of FANCJ and RAP80 exposed to MMC are attributed to single-stranded DNA created by Mre11 and CtIP nucleases. Altogether, our cell-based findings together with biochemical studies suggest a critical function of FANCJ to suppress incompletely processed and toxic joint DNA molecules during repair of ICL-induced DNA damage.
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Affiliation(s)
- Sanket Awate
- Laboratory of Molecular Gerontology, National Institute on Aging, NIH, Baltimore, MD, USA
| | - Joshua A Sommers
- Laboratory of Molecular Gerontology, National Institute on Aging, NIH, Baltimore, MD, USA
| | - Arindam Datta
- Laboratory of Molecular Gerontology, National Institute on Aging, NIH, Baltimore, MD, USA
| | - Sumeet Nayak
- Department of Cancer Biology, University of Massachusetts Medical School - UMASS Memorial Cancer Center, Worcester, MA, USA
| | - Marina A Bellani
- Laboratory of Molecular Gerontology, National Institute on Aging, NIH, Baltimore, MD, USA
| | - Olivia Yang
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University, Baltimore, MD, USA
| | - Christopher A Dunn
- Flow Cytometry Unit, National Institute on Aging, NIH, Baltimore, MD, USA
| | - Claudia M Nicolae
- Department of Biochemistry and Molecular Biology, Penn State College of Medicine, Hershey, PA, USA
| | - George-Lucian Moldovan
- Department of Biochemistry and Molecular Biology, Penn State College of Medicine, Hershey, PA, USA
| | - Michael M Seidman
- Laboratory of Molecular Gerontology, National Institute on Aging, NIH, Baltimore, MD, USA
| | - Sharon B Cantor
- Department of Cancer Biology, University of Massachusetts Medical School - UMASS Memorial Cancer Center, Worcester, MA, USA
| | - Robert M Brosh
- Laboratory of Molecular Gerontology, National Institute on Aging, NIH, Baltimore, MD, USA
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3
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Edwards DK, Watanabe-Smith K, Rofelty A, Damnernsawad A, Laderas T, Lamble A, Lind EF, Kaempf A, Mori M, Rosenberg M, d'Almeida A, Long N, Agarwal A, Sweeney DT, Loriaux M, McWeeney SK, Tyner JW. CSF1R inhibitors exhibit antitumor activity in acute myeloid leukemia by blocking paracrine signals from support cells. Blood 2019; 133:588-599. [PMID: 30425048 PMCID: PMC6367650 DOI: 10.1182/blood-2018-03-838946] [Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Accepted: 11/09/2018] [Indexed: 12/14/2022] Open
Abstract
To identify new therapeutic targets in acute myeloid leukemia (AML), we performed small-molecule and small-interfering RNA (siRNA) screens of primary AML patient samples. In 23% of samples, we found sensitivity to inhibition of colony-stimulating factor 1 (CSF1) receptor (CSF1R), a receptor tyrosine kinase responsible for survival, proliferation, and differentiation of myeloid-lineage cells. Sensitivity to CSF1R inhibitor GW-2580 was found preferentially in de novo and favorable-risk patients, and resistance to GW-2580 was associated with reduced overall survival. Using flow cytometry, we discovered that CSF1R is not expressed on the majority of leukemic blasts but instead on a subpopulation of supportive cells. Comparison of CSF1R-expressing cells in AML vs healthy donors by mass cytometry revealed expression of unique cell-surface markers. The quantity of CSF1R-expressing cells correlated with GW-2580 sensitivity. Exposure of primary AML patient samples to a panel of recombinant cytokines revealed that CSF1R inhibitor sensitivity correlated with a growth response to CSF1R ligand, CSF1, and other cytokines, including hepatocyte growth factor (HGF). The addition of CSF1 increased the secretion of HGF and other cytokines in conditioned media from AML patient samples, whereas adding GW-2580 reduced their secretion. In untreated cells, HGF levels correlated significantly with GW-2580 sensitivity. Finally, recombinant HGF and HS-5-conditioned media rescued cell viability after GW-2580 treatment in AML patient samples. Our results suggest that CSF1R-expressing cells support the bulk leukemia population through the secretion of HGF and other cytokines. This study identifies CSF1R as a novel therapeutic target of AML and provides a mechanism of paracrine cytokine/growth factor signaling in this disease.
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Affiliation(s)
- David K Edwards
- Department of Cell, Developmental & Cancer Biology, Knight Cancer Institute
| | | | - Angela Rofelty
- Division of Hematology and Medical Oncology, Knight Cancer Institute
| | | | - Ted Laderas
- Department of Medical Informatics and Clinical Epidemiology, and
| | - Adam Lamble
- Division of Hematology and Medical Oncology, Knight Cancer Institute
| | - Evan F Lind
- Division of Hematology and Medical Oncology, Knight Cancer Institute
| | - Andy Kaempf
- Biostatistics Shared Resource, Knight Cancer Institute, Oregon Health & Science University, Portland, OR; and
| | - Motomi Mori
- Biostatistics Shared Resource, Knight Cancer Institute, Oregon Health & Science University, Portland, OR; and
- School of Public Health, Oregon Health & Science University-Portland State University, Portland, OR
| | - Mara Rosenberg
- Division of Hematology and Medical Oncology, Knight Cancer Institute
| | - Amanda d'Almeida
- Division of Hematology and Medical Oncology, Knight Cancer Institute
| | - Nicola Long
- Division of Hematology and Medical Oncology, Knight Cancer Institute
| | - Anupriya Agarwal
- Division of Hematology and Medical Oncology, Knight Cancer Institute
| | | | - Marc Loriaux
- Division of Hematology and Medical Oncology, Knight Cancer Institute
| | | | - Jeffrey W Tyner
- Department of Cell, Developmental & Cancer Biology, Knight Cancer Institute
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4
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Klug LR, Bannon AE, Javidi-Sharifi N, Town A, Fleming WH, VanSlyke JK, Musil LS, Fletcher JA, Tyner JW, Heinrich MC. LMTK3 is essential for oncogenic KIT expression in KIT-mutant GIST and melanoma. Oncogene 2018; 38:1200-1210. [PMID: 30242244 PMCID: PMC6365197 DOI: 10.1038/s41388-018-0508-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 08/01/2018] [Accepted: 08/29/2018] [Indexed: 12/18/2022]
Abstract
Certain cancers, including gastrointestinal stromal tumor (GIST) and subsets of melanoma, are caused by somatic KIT mutations that result in KIT receptor tyrosine kinase constitutive activity, which drives proliferation. The treatment of KIT-mutant GIST has been revolutionized with the advent of KIT-directed cancer therapies. KIT tyrosine kinase inhibitors (TKI) are superior to conventional chemotherapy in their ability to control advanced KIT-mutant disease. However, these therapies have a limited duration of activity due to drug-resistant secondary KIT mutations that arise (or that are selected for) during KIT TKI treatment. To overcome the problem of KIT TKI resistance, we sought to identify novel therapeutic targets in KIT-mutant GIST and melanoma cells using a human tyrosine kinome siRNA screen. From this screen, we identified lemur tyrosine kinase 3 (LMTK3) and herein describe its role as a novel KIT regulator in KIT-mutant GIST and melanoma cells. We find that LMTK3 regulated the translation rate of KIT, such that loss of LMTK3 reduced total KIT, and thus KIT downstream signaling in cancer cells. Silencing of LMTK3 decreased cell viability and increased cell death in KIT-dependent, but not KIT-independent GIST and melanoma cell lines. Notably, LMTK3 silencing reduced viability of all KIT-mutant cell lines tested, even those with drug-resistant KIT secondary mutations. Furthermore, targeting of LMTK3 with siRNA delayed KIT-dependent GIST growth in a xenograft model. Our data suggest the potential of LMTK3 as a target for treatment of patients with KIT-mutant cancer, particularly after failure of KIT TKIs.
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Affiliation(s)
- Lillian R Klug
- Portland VA Health Care System, Portland, OR, USA. .,Knight Cancer Institute, Oregon Health and Science University, Portland, OR, USA. .,Division of Hematology and Medical Oncology, Oregon Health and Science University, Portland, OR, USA.
| | - Amber E Bannon
- Portland VA Health Care System, Portland, OR, USA.,Knight Cancer Institute, Oregon Health and Science University, Portland, OR, USA.,Division of Hematology and Medical Oncology, Oregon Health and Science University, Portland, OR, USA
| | - Nathalie Javidi-Sharifi
- Knight Cancer Institute, Oregon Health and Science University, Portland, OR, USA.,Division of Hematology and Medical Oncology, Oregon Health and Science University, Portland, OR, USA
| | - Ajia Town
- Portland VA Health Care System, Portland, OR, USA.,Knight Cancer Institute, Oregon Health and Science University, Portland, OR, USA.,Division of Hematology and Medical Oncology, Oregon Health and Science University, Portland, OR, USA
| | - William H Fleming
- Knight Cancer Institute, Oregon Health and Science University, Portland, OR, USA.,Division of Hematology and Medical Oncology, Oregon Health and Science University, Portland, OR, USA.,Department of Pediatrics, Oregon Stem Cell Center, Oregon Health and Science University, Portland, OR, USA
| | - Judy K VanSlyke
- Department of Biochemistry and Molecular Biology, Oregon Health and Science University, Portland, OR, USA
| | - Linda S Musil
- Department of Biochemistry and Molecular Biology, Oregon Health and Science University, Portland, OR, USA
| | - Jonathan A Fletcher
- Department of Pathology, Brigham and Women's Hospital, Boston, MA, USA.,Department of Pediatrics, Brigham and Women's Hospital, Boston, MA, USA
| | - Jeffrey W Tyner
- Knight Cancer Institute, Oregon Health and Science University, Portland, OR, USA.,Division of Hematology and Medical Oncology, Oregon Health and Science University, Portland, OR, USA
| | - Michael C Heinrich
- Portland VA Health Care System, Portland, OR, USA.,Knight Cancer Institute, Oregon Health and Science University, Portland, OR, USA.,Division of Hematology and Medical Oncology, Oregon Health and Science University, Portland, OR, USA
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5
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Kanojia D, Garg M, Martinez J, M T A, Luty SB, Doan NB, Said JW, Forscher C, Tyner JW, Koeffler HP. Kinase profiling of liposarcomas using RNAi and drug screening assays identified druggable targets. J Hematol Oncol 2017; 10:173. [PMID: 29132397 PMCID: PMC5683536 DOI: 10.1186/s13045-017-0540-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 11/06/2017] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Liposarcoma, the most common soft tissue tumor, is understudied cancer, and limited progress has been made in the treatment of metastatic disease. The Achilles heel of cancer often is their kinases that are excellent therapeutic targets. However, very limited knowledge exists of therapeutic critical kinase targets in liposarcoma that could be potentially used in disease management. METHODS Large RNAi and small-molecule tyrosine kinase inhibitor screens were performed against the proliferative capacity of liposarcoma cell lines of different subtypes. Each small molecule inhibitor was either FDA approved or in a clinical trial. RESULTS Screening assays identified several previously unrecognized targets including PTK2 and KIT in liposarcoma. We also observed that ponatinib, multi-targeted tyrosine kinase inhibitor, was the most effective drug with anti-growth effects against all cell lines. In vitro assays showed that ponatinib inhibited the clonogenic proliferation of liposarcoma, and this anti-growth effect was associated with apoptosis and cell cycle arrest at the G0/G1 phase as well as a decrease in the KIT signaling pathway. In addition, ponatinib inhibited in vivo growth of liposarcoma in a xenograft model. CONCLUSIONS Two large-scale kinase screenings identified novel liposarcoma targets and a FDA-approved inhibitor, ponatinib with clear anti-liposarcoma activity highlighting its potential therapy for treatment of this deadly tumor.
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Affiliation(s)
- Deepika Kanojia
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, 117599, Singapore.
| | - Manoj Garg
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, 117599, Singapore
| | - Jacqueline Martinez
- Cell, Developmental & Cancer, Oregon Health & Science University, Portland, Oregon, 97239, USA
| | - Anand M T
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, 117599, Singapore
| | - Samuel B Luty
- Cell, Developmental & Cancer, Oregon Health & Science University, Portland, Oregon, 97239, USA
| | - Ngan B Doan
- Department of Pathology and Laboratory Medicine, Ronald Reagan UCLA Medical Center, Los Angeles, California, 90095, USA
| | - Jonathan W Said
- Department of Pathology and Laboratory Medicine, Ronald Reagan UCLA Medical Center, Los Angeles, California, 90095, USA
| | - Charles Forscher
- Division of Hematology/Oncology, Cedars-Sinai Medical Center, University of California School of Medicine, Los Angeles, California, 90048, USA
| | - Jeffrey W Tyner
- Cell, Developmental & Cancer, Oregon Health & Science University, Portland, Oregon, 97239, USA
| | - H Phillip Koeffler
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, 117599, Singapore.,Division of Hematology/Oncology, Cedars-Sinai Medical Center, University of California School of Medicine, Los Angeles, California, 90048, USA.,National University Cancer Institute, National University Hospital, Singapore, 119074, Singapore
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6
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EPHB4 is a therapeutic target in AML and promotes leukemia cell survival via AKT. Blood Adv 2017; 1:1635-1644. [PMID: 29296810 DOI: 10.1182/bloodadvances.2017005694] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 07/05/2017] [Indexed: 02/01/2023] Open
Abstract
EPHB4, an ephrin type B receptor, is implicated in the growth of several epithelial tumors and is a promising target in cancer therapy; however, little is known about its role in hematologic malignancies. In this article, we show that EPHB4 is highly expressed in ∼30% of acute myeloid leukemia (AML) samples. In an unbiased RNA interference screen of primary leukemia samples, we found that EPHB4 drives survival in a subset of AML cases. Knockdown of EPHB4 inhibits phosphatidylinositol 3-kinase/AKT signaling, and this is accompanied by a reduction in cell viability, which can be rescued by a constitutively active form of AKT. Finally, targeting EPHB4 with a highly specific monoclonal antibody (MAb131) is effective against AML in vitro and in vivo. EPHB4 is therefore a potential target in AML with high EPHB4 expression.
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7
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Tushir-Singh J. Antibody-siRNA conjugates: drugging the undruggable for anti-leukemic therapy. Expert Opin Biol Ther 2016; 17:325-338. [PMID: 27977315 DOI: 10.1080/14712598.2017.1273344] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
INTRODUCTION Generating effective RNAi-based therapies with the potential to achieve leukemia remission remains critical unmet need. Despite a growing number of leukemia clinical trials, tissue specific delivery of therapeutic siRNA is a major roadblock in translating its clinical potential. The most recent reports in the antibody-siRNA-conjugates (ARCs) field add new dimensions to leukemic therapy, where a covalently ligated therapeutic antisense-RNA with the potential to repress the oncogenic transcript is selectively delivered into the cancer cells. Despite ARC localization to leukemic cells due to high affinity antigen-antibody interactions, multiple challenges exist to unlock the therapeutic potential of siRNA targeting. Areas covered: This review focuses on antibody and siRNA-based therapies for leukemia as well as potential antibody engineering-based strategies to generate an optimal ARC platform. Expert opinion: In vitro and clinical results have revealed that non-targeted delivery and inefficient cellular internalization of therapeutic siRNA are major contributing factors for the lack of efficacy in leukemia patients. Rational antibody design and selective protein engineering with the potential to neutralize siRNA charge, stabilize ARC complex, restrict off-targeted delivery, optimize endosomal escape, and extend serum half-life will generate clinically relevant leukemic therapies that are safe, selective, and effective.
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Affiliation(s)
- Jogender Tushir-Singh
- a Laboratory of Novel Biologics, Department of Biochemistry & Molecular Genetics , University of Virginia Cancer Center, University of Virginia School of Medicine , Charlottesville , VA , USA
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8
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Bajaj J, Konuma T, Lytle NK, Kwon HY, Ablack JN, Cantor JM, Rizzieri D, Chuah C, Oehler VG, Broome EH, Ball ED, van der Horst EH, Ginsberg MH, Reya T. CD98-Mediated Adhesive Signaling Enables the Establishment and Propagation of Acute Myelogenous Leukemia. Cancer Cell 2016; 30:792-805. [PMID: 27908736 PMCID: PMC5137811 DOI: 10.1016/j.ccell.2016.10.003] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 05/06/2016] [Accepted: 10/03/2016] [Indexed: 12/15/2022]
Abstract
Acute myelogenous leukemia (AML) is an aggressive disease associated with drug resistance and relapse. To improve therapeutic strategies, it is critical to better understand the mechanisms that underlie AML progression. Here we show that the integrin binding glycoprotein CD98 plays a central role in AML. CD98 promotes AML propagation and lethality by driving engagement of leukemia cells with their microenvironment and maintaining leukemic stem cells. Further, delivery of a humanized anti-CD98 antibody blocks growth of patient-derived AML, highlighting the importance of this pathway in human disease. These findings indicate that microenvironmental interactions are key regulators of AML and that disrupting these signals with targeted inhibitors such as CD98 antibodies may be a valuable therapeutic approach for adults and children with this disease.
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Affiliation(s)
- Jeevisha Bajaj
- Department of Pharmacology, University of California San Diego School of Medicine, La Jolla, CA 92093, USA; Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037, USA; Moores Cancer Center, University of California San Diego School of Medicine, La Jolla, CA 92093, USA; Department of Medicine, University of California San Diego School of Medicine, La Jolla, CA 92093, USA
| | - Takaaki Konuma
- Department of Pharmacology, University of California San Diego School of Medicine, La Jolla, CA 92093, USA; Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037, USA; Moores Cancer Center, University of California San Diego School of Medicine, La Jolla, CA 92093, USA; Department of Medicine, University of California San Diego School of Medicine, La Jolla, CA 92093, USA
| | - Nikki K Lytle
- Department of Pharmacology, University of California San Diego School of Medicine, La Jolla, CA 92093, USA; Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037, USA; Moores Cancer Center, University of California San Diego School of Medicine, La Jolla, CA 92093, USA; Department of Medicine, University of California San Diego School of Medicine, La Jolla, CA 92093, USA
| | - Hyog Young Kwon
- Department of Pharmacology, University of California San Diego School of Medicine, La Jolla, CA 92093, USA; Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037, USA; Moores Cancer Center, University of California San Diego School of Medicine, La Jolla, CA 92093, USA; Department of Medicine, University of California San Diego School of Medicine, La Jolla, CA 92093, USA
| | - Jailal N Ablack
- Department of Medicine, University of California San Diego School of Medicine, La Jolla, CA 92093, USA
| | - Joseph M Cantor
- Department of Medicine, University of California San Diego School of Medicine, La Jolla, CA 92093, USA
| | - David Rizzieri
- Division of Cell Therapy, Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA
| | - Charles Chuah
- Department of Haematology, Singapore General Hospital, Cancer and Stem Cell Biology Program, Duke-NUS Graduate Medical School, Singapore 169857, Singapore
| | - Vivian G Oehler
- Clinical Research Division, Fred Hutchinson Cancer Research Center, WA 98109, USA
| | - Elizabeth H Broome
- Moores Cancer Center, University of California San Diego School of Medicine, La Jolla, CA 92093, USA; Department of Pathology, University of California San Diego School of Medicine, La Jolla, CA 92093, USA
| | - Edward D Ball
- Moores Cancer Center, University of California San Diego School of Medicine, La Jolla, CA 92093, USA; Department of Medicine, Blood and Marrow Transplantation Division, University of California San Diego School of Medicine, La Jolla, CA 92093, USA
| | | | - Mark H Ginsberg
- Moores Cancer Center, University of California San Diego School of Medicine, La Jolla, CA 92093, USA; Department of Medicine, University of California San Diego School of Medicine, La Jolla, CA 92093, USA.
| | - Tannishtha Reya
- Department of Pharmacology, University of California San Diego School of Medicine, La Jolla, CA 92093, USA; Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037, USA; Moores Cancer Center, University of California San Diego School of Medicine, La Jolla, CA 92093, USA; Department of Medicine, University of California San Diego School of Medicine, La Jolla, CA 92093, USA.
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9
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Traer E, Martinez J, Javidi-Sharifi N, Agarwal A, Dunlap J, English I, Kovacsovics T, Tyner JW, Wong M, Druker BJ. FGF2 from Marrow Microenvironment Promotes Resistance to FLT3 Inhibitors in Acute Myeloid Leukemia. Cancer Res 2016; 76:6471-6482. [PMID: 27671675 DOI: 10.1158/0008-5472.can-15-3569] [Citation(s) in RCA: 94] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 09/14/2016] [Accepted: 09/14/2016] [Indexed: 12/16/2022]
Abstract
Potent FLT3 inhibitors, such as quizartinib (AC220), have shown promise in treating acute myeloid leukemia (AML) containing FLT3 internal tandem duplication (ITD) mutations. However, responses are not durable and resistance develops within months. In this study, we outline a two-step model of resistance whereby extrinsic microenvironmental proteins FLT3 ligand (FL) and fibroblast growth factor 2 (FGF2) protect FLT3-ITD+ MOLM14 cells from AC220, providing time for subsequent accumulation of ligand-independent resistance mechanisms. FL directly attenuated AC220 inhibition of FLT3, consistent with previous reports. Conversely, FGF2 promoted resistance through activation of FGFR1 and downstream MAPK effectors; these resistant cells responded synergistically to combinatorial inhibition of FGFR1 and FLT3. Removing FL or FGF2 from ligand-dependent resistant cultures transiently restored sensitivity to AC220, but accelerated acquisition of secondary resistance via reactivation of FLT3 and RAS/MAPK signaling. FLT3-ITD AML patients treated with AC220 developed increased FGF2 expression in marrow stromal cells, which peaked prior to overt clinical relapse and detection of resistance mutations. Overall, these results support a strategy of early combination therapy to target early survival signals from the bone marrow microenvironment, in particular FGF2, to improve the depth of response in FLT3-ITD AML. Cancer Res; 76(22); 6471-82. ©2016 AACR.
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Affiliation(s)
- Elie Traer
- Knight Cancer Institute, Oregon Health and Science University, Portland, Oregon. .,Division of Hematology and Medical Oncology, Oregon Health and Science University, Portland, Oregon
| | - Jacqueline Martinez
- Knight Cancer Institute, Oregon Health and Science University, Portland, Oregon
| | | | - Anupriya Agarwal
- Knight Cancer Institute, Oregon Health and Science University, Portland, Oregon.,Division of Hematology and Medical Oncology, Oregon Health and Science University, Portland, Oregon
| | - Jennifer Dunlap
- Knight Cancer Institute, Oregon Health and Science University, Portland, Oregon.,Department of Anatomic Pathology, Oregon Health and Science University, Portland, Oregon
| | - Isabel English
- Knight Cancer Institute, Oregon Health and Science University, Portland, Oregon
| | - Tibor Kovacsovics
- BMT, Blood and Marrow Transplant, Huntsman Cancer Institute, Salt Lake City, Utah
| | - Jeffrey W Tyner
- Knight Cancer Institute, Oregon Health and Science University, Portland, Oregon.,Department of Cell, Developmental, and Cancer Biology, Oregon Health and Science University, Portland, Oregon
| | - Melissa Wong
- Knight Cancer Institute, Oregon Health and Science University, Portland, Oregon.,Department of Cell, Developmental, and Cancer Biology, Oregon Health and Science University, Portland, Oregon
| | - Brian J Druker
- Knight Cancer Institute, Oregon Health and Science University, Portland, Oregon.,Division of Hematology and Medical Oncology, Oregon Health and Science University, Portland, Oregon.,Howard Hughes Medical Institute, Chevy Chase, Maryland
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10
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Abstract
RNAi-mediated screening has been an integral tool for biological discovery for the past 15 years. A variety of approaches have been employed for implementation of this technique, including pooled, depletion/enrichment screening with lentiviral shRNAs, and segregated screening of panels of individual siRNAs. The latter approach of siRNA panel screening requires efficient methods for transfection of siRNAs into the target cells. In the case of suspension leukemia cell lines and primary cells, many of the conventional transfection techniques using liposomal or calcium phosphate-mediated transfection provide very low efficiency. In this case, electroporation is the only transfection technique offering high efficiency transfection of siRNAs into the target leukemia cells. Here, we describe methods for optimization and implementation of siRNA electroporation into leukemia cell lines and primary patient specimens, and we further offer suggested electroporation settings for some commonly used leukemia cell lines.
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11
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van der Sligte NE, Kampen KR, de Bont ESJM. Can kinomics and proteomics bridge the gap between pediatric cancers and newly designed kinase inhibitors? Cell Mol Life Sci 2015; 72:3589-98. [PMID: 26321002 PMCID: PMC4565869 DOI: 10.1007/s00018-015-2019-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Revised: 07/26/2015] [Accepted: 07/27/2015] [Indexed: 11/25/2022]
Abstract
The introduction of kinase inhibitors in cancer medicine has transformed chronic myeloid leukemia from a fatal disease into a leukemia subtype with a favorable prognosis by interfering with the constitutively active kinase BCR-ABL. This success story has resulted in the development of multiple kinase inhibitors. We are currently facing significant limitations in implementing these kinase inhibitors into the clinic for the treatment of pediatric malignancies. As many hallmarks of cancer are known to be regulated by intracellular protein signaling networks, we suggest focusing on these networks to improve the implementation of kinase inhibitors. This viewpoint will provide a short overview of currently used strategies for the implementation of kinase inhibitors as well as reasons why kinase inhibitors have unfortunately not yet been widely used for the treatment of pediatric cancers. We argue that by using a future personalized medicine strategy combining kinomics, proteomics, and drug screen approaches, the gap between pediatric cancers and the use of kinase inhibitors may be bridged.
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Affiliation(s)
- Naomi E van der Sligte
- Division of Pediatric Oncology/Hematology, Department of Pediatrics, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, PO Box 30.001, 9700, Groningen, The Netherlands
| | - Kim R Kampen
- Division of Pediatric Oncology/Hematology, Department of Pediatrics, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, PO Box 30.001, 9700, Groningen, The Netherlands
| | - Eveline S J M de Bont
- Division of Pediatric Oncology/Hematology, Department of Pediatrics, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, PO Box 30.001, 9700, Groningen, The Netherlands.
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12
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Lin XD, Yang HW, Ma S, Li WW, Zhang CH, Wang WJ, Xiang R, Li LL, Yang SY. Discovery of 6-phenylimidazo[2,1-b]thiazole derivatives as a new type of FLT3 inhibitors. Bioorg Med Chem Lett 2015; 25:4534-8. [PMID: 26342867 DOI: 10.1016/j.bmcl.2015.08.068] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2015] [Revised: 08/23/2015] [Accepted: 08/26/2015] [Indexed: 02/05/2023]
Abstract
In this investigation, a series of 6-phenylimidazo[2,1-b]thiazole derivatives were synthesized. Structure-activity relationship (SAR) analysis of these compounds based on cellular assays led to the discovery of a number of compounds that showed potent activity against FLT3-dependent human acute myeloid leukemia (AML) cell line MV4-11, but very weak or no activity against FLT3-independent human cervical cancer cell line Hela. FLT3 kinase inhibition assays were then performed on the three most active compounds. Among these compounds, 6-(4-(3-(5-(tert-butyl)isoxazol- 3-yl)ureido)phenyl)-N-(3-(dimethylamino)propyl)imidazo[2,1-b]thiazole-3-carboxamide (19) exhibited the highest potency in both cellular (MV4-11, IC50: 0.002 μM) and enzymatic (FLT3, IC50: 0.022 μM) assays. Further in-depth in vitro anti-AML activity and mechanism of action studies were carried out on compound 19.
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Affiliation(s)
- Xing-Dong Lin
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Sichuan 610041, China
| | - Hui-Wen Yang
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Sichuan 610041, China
| | - Shuang Ma
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Sichuan 610041, China
| | - Wei-Wei Li
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Sichuan 610041, China
| | - Chun-Hui Zhang
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Sichuan 610041, China
| | - Wen-Jing Wang
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Sichuan 610041, China
| | - Rong Xiang
- Department of Clinical Medicine, School of Medicine, Nankai University, Tianjin, China
| | - Lin-Li Li
- West China School of Pharmacy, Sichuan University, Sichuan 610041, China.
| | - Sheng-Yong Yang
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Sichuan 610041, China.
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13
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Progress in RNAi-mediated Molecular Therapy of Acute and Chronic Myeloid Leukemia. MOLECULAR THERAPY. NUCLEIC ACIDS 2015; 4:e240. [DOI: 10.1038/mtna.2015.13] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 03/26/2015] [Indexed: 02/08/2023]
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14
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Javidi-Sharifi N, Traer E, Martinez J, Gupta A, Taguchi T, Dunlap J, Heinrich MC, Corless CL, Rubin BP, Druker BJ, Tyner JW. Crosstalk between KIT and FGFR3 Promotes Gastrointestinal Stromal Tumor Cell Growth and Drug Resistance. Cancer Res 2014; 75:880-91. [PMID: 25432174 DOI: 10.1158/0008-5472.can-14-0573] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Kinase inhibitors such as imatinib have dramatically improved outcomes for patients with gastrointestinal stromal tumor (GIST), but many patients develop resistance to these treatments. Although in some patients this event corresponds with mutations in the GIST driver oncogenic kinase KIT, other patients develop resistance without KIT mutations. In this study, we address this patient subset in reporting a functional dependence of GIST on the FGF receptor FGFR3 and its crosstalk with KIT in GIST cells. Addition of the FGFR3 ligand FGF2 to GIST cells restored KIT phosphorylation during imatinib treatment, allowing sensitive cells to proliferate in the presence of the drug. FGF2 expression was increased in imatinib-resistant GIST cells, the growth of which was blocked by RNAi-mediated silencing of FGFR3. Moreover, combining KIT and FGFR3 inhibitors synergized to block the growth of imatinib-resistant cells. Signaling crosstalk between KIT and FGFR3 activated the MAPK pathway to promote resistance to imatinib. Clinically, an IHC analysis of tumor specimens from imatinib-resistant GIST patients revealed a relative increase in FGF2 levels, with a trend toward increased expression in imatinib-naïve samples consistent with possible involvement in drug resistance. Our findings provide a mechanistic rationale to evaluate existing FGFR inhibitors and multikinase inhibitors that target FGFR3 as promising strategies to improve treatment of patients with GIST with de novo or acquired resistance to imatinib.
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Affiliation(s)
- Nathalie Javidi-Sharifi
- Knight Cancer Institute, Oregon Health and Science University, Portland, Oregon. Division of Hematology and Medical Oncology, Oregon Health and Science University, Portland, Oregon
| | - Elie Traer
- Knight Cancer Institute, Oregon Health and Science University, Portland, Oregon. Division of Hematology and Medical Oncology, Oregon Health and Science University, Portland, Oregon
| | - Jacqueline Martinez
- Knight Cancer Institute, Oregon Health and Science University, Portland, Oregon
| | - Anu Gupta
- Department of Molecular Genetics, Lerner Research Institute, Cleveland, Ohio
| | - Takehiro Taguchi
- Division of Human Health and Medical Science, Graduate School of Kuroshio Science, Kochi University, Nankoku, Kochi, Japan
| | - Jennifer Dunlap
- Knight Cancer Institute, Oregon Health and Science University, Portland, Oregon. Department of Anatomic Pathology, Oregon Health and Science University, Portland, Oregon
| | - Michael C Heinrich
- Knight Cancer Institute, Oregon Health and Science University, Portland, Oregon. Division of Hematology and Medical Oncology, Oregon Health and Science University, Portland, Oregon. Portland VA Medical Center, Portland, Oregon
| | - Christopher L Corless
- Knight Cancer Institute, Oregon Health and Science University, Portland, Oregon. Department of Anatomic Pathology, Oregon Health and Science University, Portland, Oregon
| | - Brian P Rubin
- Department of Molecular Genetics, Lerner Research Institute, Cleveland, Ohio. Taussig Cancer Center, Cleveland Clinic, Cleveland, Ohio. Department of Anatomic Pathology, Cleveland Clinic, Cleveland, Ohio
| | - Brian J Druker
- Knight Cancer Institute, Oregon Health and Science University, Portland, Oregon. Division of Hematology and Medical Oncology, Oregon Health and Science University, Portland, Oregon. Howard Hughes Medical Institute, Portland, Oregon
| | - Jeffrey W Tyner
- Knight Cancer Institute, Oregon Health and Science University, Portland, Oregon. Department of Cell, Developmental and Cancer Biology, Oregon Health and Science University, Portland, Oregon.
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15
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Agarwal A, MacKenzie RJ, Eide CA, Davare MA, Watanabe-Smith K, Tognon CE, Mongoue-Tchokote S, Park B, Braziel RM, Tyner JW, Druker BJ. Functional RNAi screen targeting cytokine and growth factor receptors reveals oncorequisite role for interleukin-2 gamma receptor in JAK3-mutation-positive leukemia. Oncogene 2014; 34:2991-9. [PMID: 25109334 PMCID: PMC4324389 DOI: 10.1038/onc.2014.243] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2014] [Revised: 05/23/2014] [Accepted: 06/15/2014] [Indexed: 01/25/2023]
Abstract
To understand the role of cytokine and growth factor receptor-mediated signaling in leukemia pathogenesis, we designed a functional RNA interference (RNAi) screen targeting 188 cytokine and growth factor receptors that we found highly expressed in primary leukemia specimens. Using this screen, we identified interleukin-2 gamma receptor (IL2Rγ) as a critical growth determinant for a JAK3(A572V) mutation-positive acute myeloid leukemia cell line. We observed that knockdown of IL2Rγ abrogates phosphorylation of JAK3 and downstream signaling molecules, JAK1, STAT5, MAPK and pS6 ribosomal protein. Overexpression of IL2Rγ in murine cells increased the transforming potential of activating JAK3 mutations, whereas absence of IL2Rγ completely abrogated the clonogenic potential of JAK3(A572V), as well as the transforming potential of additional JAK3-activating mutations such as JAK3(M511I). In addition, mutation at the IL2Rγ interaction site in the FERM domain of JAK3 (Y100C) completely abrogated JAK3-mediated leukemic transformation. Mechanistically, we found IL2Rγ contributes to constitutive JAK3 mutant signaling by increasing JAK3 expression and phosphorylation. Conversely, we found that mutant, but not wild-type JAK3, increased the expression of IL2Rγ, indicating IL2Rγ and JAK3 contribute to constitutive JAK/STAT signaling through their reciprocal regulation. Overall, we demonstrate a novel role for IL2Rγ in potentiating oncogenesis in the setting of JAK3-mutation-positive leukemia. In addition, our study highlights an RNAi-based functional assay that can be used to facilitate the identification of non-kinase cytokine and growth factor receptor targets for inhibiting leukemic cell growth.
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Affiliation(s)
- A Agarwal
- 1] Division of Hematology and Medical Oncology, Oregon Health & Science University, Portland, OR, USA [2] Knight Cancer Institute, Oregon Health & Science University, Portland, OR, USA
| | - R J MacKenzie
- 1] Division of Hematology and Medical Oncology, Oregon Health & Science University, Portland, OR, USA [2] Knight Cancer Institute, Oregon Health & Science University, Portland, OR, USA
| | - C A Eide
- 1] Division of Hematology and Medical Oncology, Oregon Health & Science University, Portland, OR, USA [2] Knight Cancer Institute, Oregon Health & Science University, Portland, OR, USA [3] Howard Hughes Medical Institute, Portland, OR, USA
| | - M A Davare
- Department of Pediatrics, Oregon Health & Science University, Portland, OR, USA
| | - K Watanabe-Smith
- 1] Division of Hematology and Medical Oncology, Oregon Health & Science University, Portland, OR, USA [2] Knight Cancer Institute, Oregon Health & Science University, Portland, OR, USA
| | - C E Tognon
- 1] Knight Cancer Institute, Oregon Health & Science University, Portland, OR, USA [2] Howard Hughes Medical Institute, Portland, OR, USA
| | - S Mongoue-Tchokote
- 1] Knight Cancer Institute, Oregon Health & Science University, Portland, OR, USA [2] Biostatistics Shared Resource, Oregon Health & Science University, Portland, OR, USA
| | - B Park
- 1] Knight Cancer Institute, Oregon Health & Science University, Portland, OR, USA [2] Biostatistics Shared Resource, Oregon Health & Science University, Portland, OR, USA
| | - R M Braziel
- Department of Pathology, Oregon Health & Science University, Portland, OR, USA
| | - J W Tyner
- 1] Knight Cancer Institute, Oregon Health & Science University, Portland, OR, USA [2] Department of Cell & Developmental Biology, Oregon Health & Science University, Portland, OR, USA
| | - B J Druker
- 1] Division of Hematology and Medical Oncology, Oregon Health & Science University, Portland, OR, USA [2] Knight Cancer Institute, Oregon Health & Science University, Portland, OR, USA [3] Howard Hughes Medical Institute, Portland, OR, USA
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16
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Aly RM, Ghazy HF. High expression of GTPase regulator associated with the focal adhesion kinase (GRAF) is a favorable prognostic factor in acute myeloid leukemia. Blood Cells Mol Dis 2014; 53:185-8. [PMID: 25088035 DOI: 10.1016/j.bcmd.2014.07.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2014] [Revised: 07/06/2014] [Accepted: 07/07/2014] [Indexed: 11/15/2022]
Abstract
BACKGROUND GRAF is a recognized tumor suppressor gene that was found inactivated in AML. However, the prognostic role of a GRAF transcript has not been studied in patients with AML. METHODS In this study, we investigated the expression of the GRAF transcript by real time quantitative PCR in 60 AML patients and 30 healthy age and sex matched controls. RESULTS GRAF expression was significantly lower in patients with AML when compared to controls (P=0.008). There were no significant differences in clinical features, FAB subtypes and cytogenetic risk subgroups between patients with high and low GRAF expression levels. Kaplan-Meier analysis showed that patients with high GRAF expression had longer overall survival (OS). Multivariate analysis revealed that, besides WBC count, GRAF expression was also an independent prognostic factor for AML. CONCLUSION We provide evidence that high GRAF expression is a favorable prognostic marker in patients with AML.
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Affiliation(s)
- Rabab M Aly
- Clinical Pathology Department, Faculty of Medicine, Mansoura University, Mansoura, Egypt.
| | - Hayam F Ghazy
- Medical Oncology Unit, Internal Medicine Department, Faculty of Medicine, Mansoura University, Mansoura, Egypt
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17
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Gustafsson K, Jamalpour M, Trinh C, Kharas MG, Welsh M. The Src homology-2 protein Shb modulates focal adhesion kinase signaling in a BCR-ABL myeloproliferative disorder causing accelerated progression of disease. J Hematol Oncol 2014; 7:45. [PMID: 24952416 PMCID: PMC4074852 DOI: 10.1186/1756-8722-7-45] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2014] [Accepted: 06/19/2014] [Indexed: 01/09/2023] Open
Abstract
Background The Src homology-2 domain protein B (Shb) is an adapter protein operating downstream of several tyrosine kinase receptors and consequently Shb regulates various cellular responses. Absence of Shb was recently shown to reduce hematopoietic stem cell proliferation through activation of focal adhesion kinase (FAK) and thus we sought to investigate Shb’s role in the progression of leukemia. Methods Wild type and Shb knockout bone marrow cells were transformed with a retroviral BCR-ABL construct and subsequently transplanted to wild type or Shb knockout recipients. Disease latency, bone marrow and peripheral blood cell characteristics, cytokine expression, signaling characteristics and colony formation were determined by flow cytometry, qPCR, western blotting and methylcellulose colony forming assays. Results It was observed that Shb knockout BCR-ABL-transformed bone marrow cells produced a disease with death occurring at earlier time points compared with corresponding wild type controls due to elevated proliferation of transformed bone marrow cells. Moreover, significantly elevated interleukin-6 and granulocyte colony-stimulation factor mRNA levels were observed in Shb knockout c-Kit + leukemic bone marrow cells providing a plausible explanation for the concurrent peripheral blood neutrophilia. Shb knockout leukemic bone marrow cells also showed increased ability to form colonies in methylcellulose devoid of cytokines that was dependent on the concomitantly observed increased activity of FAK. Transplanting BCR-ABL-transformed Shb knockout bone marrow cells to Shb knockout recipients revealed decreased disease latency without neutrophilia, thus implicating the importance of niche-derived cues for the increase of blood granulocytes. Conclusions Absence of Shb accelerates disease progression by exerting dual roles in BCR-ABL-induced leukemia: increased cell expansion due to elevated FAK activity and neutrophilia in peripheral blood, the latter dependent on the genetic background of the leukemic niche.
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Affiliation(s)
| | | | | | | | - Michael Welsh
- Department of Medical Cell Biology, Uppsala University, Husargatan 3, 75123 Uppsala, Sweden.
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18
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Abstract
Alveolar rhabdomyosarcoma (aRMS) is an aggressive myogenic childhood malignancy, not infrequently presenting as incurable metastatic disease. To identify therapeutic targets, we performed an unbiased tyrosine kinome RNA interference screen in primary cell cultures from a genetically engineered, conditional mouse model of aRMS. We identified ephrin receptor B4 (EphB4) as a target that is widely expressed in human aRMS and that portends a poor clinical outcome in an expression level-dependent manner. We also uncovered cross-talk of this ephrin receptor with another receptor tyrosine kinase, PDGFRβ, which facilitates PDGF ligand-dependent, ephrin ligand-independent activation of EphB4 converging on the Akt and Erk1/2 pathways. Conversely, EphB4 activation by its cognate ligand, EphrinB2, did not stimulate PDGFRβ; instead, apoptosis was paradoxically induced. Finally, we showed that small-molecule inhibition of both PDGFRβ and EphB4 by dasatinib resulted in a significant decrease in tumor cell viability in vitro, as well as decreased tumor growth rate and significantly prolonged survival in vivo. To our knowledge, these results are the first to identify EphB4 and its cross-talk with PDGFRβ as unexpected vital determinants of tumor cell survival in aRMS, with EphB4 at the crux of a bivalent signaling node that is either mitogenic or proapoptotic.
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19
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Clinical targeting of mutated and wild-type protein tyrosine kinases in cancer. Mol Cell Biol 2014; 34:1722-32. [PMID: 24567371 DOI: 10.1128/mcb.01592-13] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Clinical therapies for cancer have evolved from toxic, nontargeted agents to manageable, highly targeted therapies. Protein tyrosine kinases are a family of signaling molecules implicated in nearly every cancer type and are the foundation for the development of modern targeted agents. Recent genomic analyses have identified activating mutations, translocations, and amplifications of tyrosine kinases. Selective targeting of these genetically altered tyrosine kinases has resulted in significant clinical advances, including increased patient survival. This indicates that altered protein tyrosine kinases are the main drivers of many different cancers. However, lost during analyses of genetic lesions are the contributions of activated, wild-type kinases on tumor-dependent pathways. New approaches in phosphoproteomic technologies have identified several wild-type tyrosine kinase activation states, suggesting that non-genetically altered kinases can be essential "nodes" for signal transduction. Here, we summarize the evidence supporting the common mechanisms of protein tyrosine kinase activation in cancer and provide a personal perspective on the kinases BCR-ABL and BTK, as well as nonmutated kinase targets in prostate cancer, through our work. We outline the mechanisms of tyrosine kinase activation in the absence of direct mutation and discuss whether non-genetically altered tyrosine kinases or their associated downstream signaling pathways can be effectively targeted.
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20
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Kikuchi K, Hettmer S, Aslam MI, Michalek JE, Laub W, Wilky BA, Loeb DM, Rubin BP, Wagers AJ, Keller C. Cell-cycle dependent expression of a translocation-mediated fusion oncogene mediates checkpoint adaptation in rhabdomyosarcoma. PLoS Genet 2014; 10:e1004107. [PMID: 24453992 PMCID: PMC3894165 DOI: 10.1371/journal.pgen.1004107] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Accepted: 11/27/2013] [Indexed: 11/19/2022] Open
Abstract
Rhabdomyosarcoma is the most commonly occurring soft-tissue sarcoma in childhood. Most rhabdomyosarcoma falls into one of two biologically distinct subgroups represented by alveolar or embryonal histology. The alveolar subtype harbors a translocation-mediated PAX3:FOXO1A fusion gene and has an extremely poor prognosis. However, tumor cells have heterogeneous expression for the fusion gene. Using a conditional genetic mouse model as well as human tumor cell lines, we show that that Pax3:Foxo1a expression is enriched in G2 and triggers a transcriptional program conducive to checkpoint adaptation under stress conditions such as irradiation in vitro and in vivo. Pax3:Foxo1a also tolerizes tumor cells to clinically-established chemotherapy agents and emerging molecularly-targeted agents. Thus, the surprisingly dynamic regulation of the Pax3:Foxo1a locus is a paradigm that has important implications for the way in which oncogenes are modeled in cancer cells. Rare childhood cancers can be paradigms from which important new principles can be discerned. The childhood muscle cancer rhabdomyosarcoma is no exception, having been the focus of the original 1969 description by Drs. Li and Fraumeni of a syndrome now know to be commonly caused by underlying p53 tumor suppressor loss-of-function. In our studies using a conditional genetic mouse model of alveolar rhabdomyosarcoma in conjunction with human tumor cell lines, we have uncovered that the expression level of a translocation-mediated fusion gene, Pax3:Foxo1a, is dynamic and varies during the cell cycle. Our studies support that Pax3:Foxo1a facilitate the yeast-related process of checkpoint adaptation under stresses such as irradiation. The broader implication of our studies is that distal cis elements (promoter-influencing regions of DNA) may be critical to fully understanding the function of cancer-associated translocations.
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Affiliation(s)
- Ken Kikuchi
- Pediatric Cancer Biology Program, Papé Family Pediatric Research Institute, Department of Pediatrics, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Simone Hettmer
- The Howard Hughes Medical Institute and Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts, United States of America, and Joslin Diabetes Center, Boston, Massachusetts, United States of America
- Department of Pediatric Oncology, Dana Farber Cancer Institute and Division of Pediatric Hematology/Oncology, Children's Hospital, Boston, Massachusetts, United States of America
| | - M. Imran Aslam
- Pediatric Cancer Biology Program, Papé Family Pediatric Research Institute, Department of Pediatrics, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Joel E. Michalek
- Department of Epidemiology and Biostatistics, University of Texas Health Science Center, San Antonio, Texas, United States of America
| | - Wolfram Laub
- Department of Radiation Medicine, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Breelyn A. Wilky
- Division of Medical Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - David M. Loeb
- Division of Pediatric Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Brian P. Rubin
- Departments of Anatomic Pathology and Molecular Genetics, Taussig Cancer Center and Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio, United States of America
| | - Amy J. Wagers
- The Howard Hughes Medical Institute and Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts, United States of America, and Joslin Diabetes Center, Boston, Massachusetts, United States of America
| | - Charles Keller
- Pediatric Cancer Biology Program, Papé Family Pediatric Research Institute, Department of Pediatrics, Oregon Health & Science University, Portland, Oregon, United States of America
- * E-mail:
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21
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Ponatinib overcomes FGF2-mediated resistance in CML patients without kinase domain mutations. Blood 2014; 123:1516-24. [PMID: 24408322 DOI: 10.1182/blood-2013-07-518381] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Development of resistance to kinase inhibitors remains a clinical challenge. Kinase domain mutations are a common mechanism of resistance in chronic myeloid leukemia (CML), yet the mechanism of resistance in the absence of mutations remains unclear. We tested proteins from the bone marrow microenvironment and found that FGF2 promotes resistance to imatinib in vitro. Fibroblast growth factor 2 (FGF2) was uniquely capable of promoting growth in both short- and long-term assays through the FGF receptor 3/RAS/c-RAF/mitogen-activated protein kinase pathway. Resistance could be overcome with ponatinib, a multikinase inhibitor that targets BCR-ABL and FGF receptor. Clinically, we identified CML patients without kinase domain mutations who were resistant to multiple ABL kinase inhibitors and responded to ponatinib treatment. In comparison to CML patients with kinase domain mutations, these patients had increased FGF2 in their bone marrow when analyzed by immunohistochemistry. Moreover, FGF2 in the marrow decreased concurrently with response to ponatinib, further suggesting that FGF2-mediated resistance is interrupted by FGF receptor inhibition. These results illustrate the clinical importance of ligand-induced resistance to kinase inhibitors and support an approach of developing rational inhibitor combinations to circumvent resistance.
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22
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Tyrosine kinome profiling: oncogenic mutations and therapeutic targeting in cancer. Mol Oncol 2013. [DOI: 10.1017/cbo9781139046947.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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23
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Bhinder B, Djaballah H. Systematic analysis of RNAi reports identifies dismal commonality at gene-level and reveals an unprecedented enrichment in pooled shRNA screens. Comb Chem High Throughput Screen 2013; 16:665-81. [PMID: 23848309 PMCID: PMC3885821 DOI: 10.2174/13862073113169990045] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Revised: 07/01/2013] [Accepted: 07/02/2013] [Indexed: 11/22/2022]
Abstract
RNA interference (RNAi) has opened promising avenues to better understand gene function. Though many RNAi screens report on the identification of genes, very few, if any, have been further studied and validated. Data discrepancy is emerging as one of RNAi main pitfalls. We reasoned that a systematic analysis of lethality-based screens, since they score for cell death, would examine the extent of hit discordance at inter-screen level. To this end, we developed a methodology for literature mining and overlap analysis of several screens using both siRNA and shRNA flavors, and obtained 64 gene lists censoring an initial list of 7,430 nominated genes. We further performed a comparative analysis first at a global level followed by hit re-assessment under much more stringent conditions. To our surprise, none of the hits overlapped across the board even for PLK1, which emerged as a strong candidate in siRNA screens; but only marginally in the shRNA ones. Furthermore, EIF5B emerges as the most common hit only in the shRNA screens. A highly unusual and unprecedented result was the observation that 5,269 out of 6,664 nominated genes (~80%) in the shRNA screens were exclusive to the pooled format, raising concerns as to the merits of pooled screens which qualify hits based on relative depletions, possibly due to multiple integrations per cell, data deconvolution or inaccuracies in intracellular processing causing off-target effects. Without golden standards in place, we would encourage the community to pay more attention to RNAi screening data analysis practices, bearing in mind that it is combinatorial in nature and one active siRNA duplex or shRNA hairpin per gene does not suffice credible hit nomination. Finally, we also would like to caution interpretation of pooled shRNA screening outcomes.
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Affiliation(s)
- Bhavneet Bhinder
- HTS Core Facility, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, USA.
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24
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Chan IJ, Kasprowicz S, Tharp MD. Distinct signalling pathways for mutated KIT(V560G) and KIT(D816V) in mastocytosis. Clin Exp Dermatol 2013; 38:538-44. [PMID: 23777495 DOI: 10.1111/ced.12000] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND The activating mutations KIT(V560G) and KIT(D816V) are associated with mastocytosis. Thus, identifying and inhibiting the signalling pathways associated with mutated KIT gene offers a potentially important strategy for the treatment of mastocytosis. AIM To correlate KIT mutations with specific signalling pathways in human mast-cell lines using pathway inhibitors. METHODS Human mast-cell (HMC) lines expressing KIT(V560G) (the cell line HMC-1) and KIT(V560G and D816V) (HMC-1.2) were treated with specific signalling pathway inhibitors for 1-5 days, and the inhibitory effects on growth were determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cell-proliferation assay, western blotting and flow cytometry. RESULTS Growth inhibitory assays and western blot analyses showed that the Janus kinase 3/signal transducer and activator of transcription (JAK3/STAT) pathway is the preferential signalling pathway for KIT(V560G), whereas the mechanistic target of rapamycin complex 1/4E-binding protein 1 (mTORC1/4E-BP1) pathway is preferentially linked to KIT(D816V). Inhibition of these critical signalling pathways results in programmed cell death. CONCLUSIONS KIT(V560G) and KIT(D816V) use different signalling pathways that promote mast-cell growth. Inhibitors of these specific pathways might be effective in treating mastocytosis.
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Affiliation(s)
- I J Chan
- Department of Dermatology, Rush University Medical Center, Chicago, IL, USA.
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25
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Discovery of siRNA lipid nanoparticles to transfect suspension leukemia cells and provide in vivo delivery capability. Mol Ther 2013; 22:359-370. [PMID: 24002693 DOI: 10.1038/mt.2013.210] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Accepted: 08/19/2013] [Indexed: 12/15/2022] Open
Abstract
As a powerful research tool, siRNA's therapeutic and target validation utility with leukemia cells and long-term gene knockdown is severely restricted by the lack of omnipotent, safe, stable, and convenient delivery. Here, we detail our discovery of siRNA-containing lipid nanoparticles (LNPs) able to effectively transfect several leukemia and difficult-to-transfect adherent cell lines also providing in vivo delivery to mouse spleen and bone marrow tissues through tail-vein administration. We disclose a series of novel structurally related lipids accounting for the superior transfection ability, and reveal a correlation between expression of Caveolins and successful transfection. These LNPs, bearing low toxicity and long stability of >6 months, are ideal for continuous long-term dosing. Our discovery represents the first effective siRNA-containing LNPs for leukemia cells, which not only enables high-throughput siRNA screening with leukemia cells and difficult-to-transfect adherent cells but also paves the way for the development of therapeutic siRNA for leukemia treatment.
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26
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Abstract
Gene silencing through RNA interference has provided researchers with an effective way to study gene function. High-throughput RNA interference (HT-RNAi) screening has further permitted researchers to identify functionally relevant mediators of cellular response on a large scale. These screens have greatly expedited the discovery of novel targets and pathway mediators. Here, we describe the methodology for performing HT-RNAi screening of HeLa cells transfected with short interfering RNA (siRNA) libraries in 384-well microplate format. Using this plate format, the HT-RNAi assay can be easily adapted to semi-automated or fully automated platforms. The library siRNA are introduced into the cells through reverse transfection using cationic lipids. HT-RNAi screening for modulators of cell proliferation can be accomplished using a single read out reagent. This type of RNAi screening can be used with most plate-based cellular assays and can be optimized for most cultured cells lines, thus becoming a powerful tool to identify specific gene modulators and targets for drug discovery.
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Tyner JW. Rapid Identification of Therapeutic Targets in Hematologic Malignancies via Functional Genomics. Ther Adv Hematol 2013; 2:83-93. [PMID: 23556079 DOI: 10.1177/2040620711403028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The clinical application of gene-targeted drugs has transformed cancer therapy. The hallmark example of this strategy is use of the ABL kinase inhibitor imatinib for treatment of patients with chronic myeloid leukemia (CML). This remarkable clinical success has also stimulated an expansive search for personalized gene targets in all patients to facilitate broad application of targeted therapy for cancer. However, achievement of this objective will require simultaneous work towards several complementary goals. The first step towards broad application of gene-targeted therapy must entail a rapid means to identify target oncogenes in individual patients. Next, we must identify well-tolerated, gene-specific drugs that are collectively effective against a wide diversity of gene targets. Finally, we must develop protocols by which individual patients are matched with appropriate, gene-targeted drugs in a clinically relevant time frame. While these may seem like difficult tasks, we are fortunate to have a wide variety of new and rapidly evolving research tools at our disposal. These include next-generation sequencing of the genome and transcriptome, single nucleotide polymorphism (SNP)/copy number variations (CNV) and gene expression microarrays, and RNAi libraries for the application of functional screens. In this review we discuss the advantages and disadvantages of each of these techniques with the goal of demonstrating that no single technique will be sufficient as a standalone technology, but rather it will be the integration of all techniques that will enable broad application of gene-targeted cancer therapies.
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Sanda T, Tyner JW, Gutierrez A, Ngo VN, Glover J, Chang BH, Yost A, Ma W, Fleischman AG, Zhou W, Yang Y, Kleppe M, Ahn Y, Tatarek J, Kelliher MA, Neuberg DS, Levine RL, Moriggl R, Müller M, Gray NS, Jamieson CHM, Weng AP, Staudt LM, Druker BJ, Look AT. TYK2-STAT1-BCL2 pathway dependence in T-cell acute lymphoblastic leukemia. Cancer Discov 2013; 3:564-77. [PMID: 23471820 DOI: 10.1158/2159-8290.cd-12-0504] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
UNLABELLED Targeted molecular therapy has yielded remarkable outcomes in certain cancers, but specific therapeutic targets remain elusive for many others. As a result of two independent RNA interference (RNAi) screens, we identified pathway dependence on a member of the Janus-activated kinase (JAK) tyrosine kinase family, TYK2, and its downstream effector STAT1, in T-cell acute lymphoblastic leukemia (T-ALL). Gene knockdown experiments consistently showed TYK2 dependence in both T-ALL primary specimens and cell lines, and a small-molecule inhibitor of JAK activity induced T-ALL cell death. Activation of this TYK2-STAT1 pathway in T-ALL cell lines occurs by gain-of-function TYK2 mutations or activation of interleukin (IL)-10 receptor signaling, and this pathway mediates T-ALL cell survival through upregulation of the antiapoptotic protein BCL2. These findings indicate that in many T-ALL cases, the leukemic cells are dependent upon the TYK2-STAT1-BCL2 pathway for continued survival, supporting the development of molecular therapies targeting TYK2 and other components of this pathway. SIGNIFICANCE In recent years, "pathway dependence" has been revealed in specific types of human cancer, which can be important because they pinpoint proteins that are particularly vulnerable to antitumor-targeted inhibition (so-called Achilles’ heel proteins). Here, we use RNAi technology to identify a novel oncogenic pathway that involves aberrant activation of the TYK2 tyrosine kinase and its downstream substrate, STAT1, which ultimately promotes T-ALL cell survival through the upregulation of BCL2 expression
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Affiliation(s)
- Takaomi Sanda
- Department of Pediatric Oncology, Children's Hospital, Boston, MA, USA
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29
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Yang LL, Li GB, Ma S, Zou C, Zhou S, Sun QZ, Cheng C, Chen X, Wang LJ, Feng S, Li LL, Yang SY. Structure–Activity Relationship Studies of Pyrazolo[3,4-d]pyrimidine Derivatives Leading to the Discovery of a Novel Multikinase Inhibitor That Potently Inhibits FLT3 and VEGFR2 and Evaluation of Its Activity against Acute Myeloid Leukemia in Vitro and in Vivo. J Med Chem 2013; 56:1641-55. [PMID: 23362959 DOI: 10.1021/jm301537p] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Ling-Ling Yang
- State
Key Laboratory of Biotherapy and Cancer Center, West China Hospital,
West China Medical School, and ‡College of Chemical Engineering, Sichuan University, Sichuan 610041,
China
| | - Guo-Bo Li
- State
Key Laboratory of Biotherapy and Cancer Center, West China Hospital,
West China Medical School, and ‡College of Chemical Engineering, Sichuan University, Sichuan 610041,
China
| | - Shuang Ma
- State
Key Laboratory of Biotherapy and Cancer Center, West China Hospital,
West China Medical School, and ‡College of Chemical Engineering, Sichuan University, Sichuan 610041,
China
| | - Chan Zou
- State
Key Laboratory of Biotherapy and Cancer Center, West China Hospital,
West China Medical School, and ‡College of Chemical Engineering, Sichuan University, Sichuan 610041,
China
| | - Shu Zhou
- State
Key Laboratory of Biotherapy and Cancer Center, West China Hospital,
West China Medical School, and ‡College of Chemical Engineering, Sichuan University, Sichuan 610041,
China
| | - Qi-Zheng Sun
- State
Key Laboratory of Biotherapy and Cancer Center, West China Hospital,
West China Medical School, and ‡College of Chemical Engineering, Sichuan University, Sichuan 610041,
China
| | - Chuan Cheng
- State
Key Laboratory of Biotherapy and Cancer Center, West China Hospital,
West China Medical School, and ‡College of Chemical Engineering, Sichuan University, Sichuan 610041,
China
| | - Xin Chen
- State
Key Laboratory of Biotherapy and Cancer Center, West China Hospital,
West China Medical School, and ‡College of Chemical Engineering, Sichuan University, Sichuan 610041,
China
| | - Li-Jiao Wang
- State
Key Laboratory of Biotherapy and Cancer Center, West China Hospital,
West China Medical School, and ‡College of Chemical Engineering, Sichuan University, Sichuan 610041,
China
| | - Shan Feng
- State
Key Laboratory of Biotherapy and Cancer Center, West China Hospital,
West China Medical School, and ‡College of Chemical Engineering, Sichuan University, Sichuan 610041,
China
| | - Lin-Li Li
- State
Key Laboratory of Biotherapy and Cancer Center, West China Hospital,
West China Medical School, and ‡College of Chemical Engineering, Sichuan University, Sichuan 610041,
China
| | - Sheng-Yong Yang
- State
Key Laboratory of Biotherapy and Cancer Center, West China Hospital,
West China Medical School, and ‡College of Chemical Engineering, Sichuan University, Sichuan 610041,
China
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30
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Bicocca VT, Chang BH, Masouleh BK, Muschen M, Loriaux MM, Druker BJ, Tyner JW. Crosstalk between ROR1 and the Pre-B cell receptor promotes survival of t(1;19) acute lymphoblastic leukemia. Cancer Cell 2012; 22:656-67. [PMID: 23153538 PMCID: PMC3500515 DOI: 10.1016/j.ccr.2012.08.027] [Citation(s) in RCA: 129] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Revised: 03/22/2012] [Accepted: 08/28/2012] [Indexed: 12/21/2022]
Abstract
We report that t(1;19) ALL cells universally exhibit expression of and dependence on the cell surface receptor ROR1. We further identify t(1;19) ALL cell sensitivity to the kinase inhibitor dasatinib due to its inhibition of the pre-B cell receptor (pre-BCR) signaling complex. These phenotypes are a consequence of developmental arrest at an intermediate/late stage of B-lineage maturation. Additionally, inhibition of pre-BCR signaling induces further ROR1 upregulation, and we identify distinct ROR1 and pre-BCR downstream signaling pathways that are modulated in a counterbalancing manner-both leading to AKT phosphorylation. Consistent with this, AKT phosphorylation is transiently eliminated after dasatinib treatment, but is partially restored following dasatinib potentiation of ROR1 expression. Consequently, ROR1 silencing accentuates dasatinib killing of t(1;19) ALL cells.
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Affiliation(s)
- Vincent T Bicocca
- Division of Hematology and Medical Oncology, Oregon Health & Science University, Portland, OR 97239, USA.
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31
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Tyner JW, Yang WF, Bankhead A, Fan G, Fletcher LB, Bryant J, Glover JM, Chang BH, Spurgeon SE, Fleming WH, Kovacsovics T, Gotlib JR, Oh ST, Deininger MW, Zwaan CM, Den Boer ML, van den Heuvel-Eibrink MM, O'Hare T, Druker BJ, Loriaux MM. Kinase pathway dependence in primary human leukemias determined by rapid inhibitor screening. Cancer Res 2012; 73:285-96. [PMID: 23087056 DOI: 10.1158/0008-5472.can-12-1906] [Citation(s) in RCA: 119] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Kinases are dysregulated in most cancers, but the frequency of specific kinase mutations is low, indicating a complex etiology in kinase dysregulation. Here, we report a strategy to rapidly identify functionally important kinase targets, irrespective of the etiology of kinase pathway dysregulation, ultimately enabling a correlation of patient genetic profiles to clinically effective kinase inhibitors. Our methodology assessed the sensitivity of primary leukemia patient samples to a panel of 66 small-molecule kinase inhibitors over 3 days. Screening of 151 leukemia patient samples revealed a wide diversity of drug sensitivities, with 70% of the clinical specimens exhibiting hypersensitivity to one or more drugs. From this data set, we developed an algorithm to predict kinase pathway dependence based on analysis of inhibitor sensitivity patterns. Applying this algorithm correctly identified pathway dependence in proof-of-principle specimens with known oncogenes, including a rare FLT3 mutation outside regions covered by standard molecular diagnostic tests. Interrogation of all 151 patient specimens with this algorithm identified a diversity of kinase targets and signaling pathways that could aid prioritization of deep sequencing data sets, permitting a cumulative analysis to understand kinase pathway dependence within leukemia subsets. In a proof-of-principle case, we showed that in vitro drug sensitivity could predict both a clinical response and the development of drug resistance. Taken together, our results suggested that drug target scores derived from a comprehensive kinase inhibitor panel could predict pathway dependence in cancer cells while simultaneously identifying potential therapeutic options.
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Affiliation(s)
- Jeffrey W Tyner
- Department of Cell and Developmental Biology, Oregon Health & Science University, Portland, OR 97239, USA
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32
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Laurence A, Pesu M, Silvennoinen O, O’Shea J. JAK Kinases in Health and Disease: An Update. Open Rheumatol J 2012; 6:232-44. [PMID: 23028408 PMCID: PMC3460320 DOI: 10.2174/1874312901206010232] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Revised: 06/25/2012] [Accepted: 06/29/2012] [Indexed: 12/22/2022] Open
Abstract
Janus kinases (Jaks) are critical signaling elements for a large subset of cytokines. As a consequence they play pivotal roles in the patho-physiology of many diseases including neoplastic and autoimmune diseases. Small molecule Jak inhibitors as therapeutic agents have become a reality and the palette of such inhibitors will likely expand. This review will summarize our current knowledge on these key enzymes and their associated pharmaceutical inhibitors.
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Affiliation(s)
- Arian Laurence
- Molecular Immunology and Inflammation Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Marko Pesu
- Institute of Biomedical Technology, FI-33014 University of Tampere, Finland
- Centre for Laboratory Medicine, FI-33520 Tampere University Hospital, Finland
| | - Olli Silvennoinen
- Institute of Biomedical Technology, FI-33014 University of Tampere, Finland
- Centre for Laboratory Medicine, FI-33520 Tampere University Hospital, Finland
| | - John O’Shea
- Molecular Immunology and Inflammation Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
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33
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Gómez-Valadés AG, Llamas M, Blanch S, Perales JC, Román J, Gómez-Casajús L, Mascaró C. Specific Jak3 Downregulation in Lymphocytes Impairs γc Cytokine Signal Transduction and Alleviates Antigen-driven Inflammation In Vivo. MOLECULAR THERAPY. NUCLEIC ACIDS 2012; 1:e42. [PMID: 23344234 PMCID: PMC3464880 DOI: 10.1038/mtna.2012.37] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Jak3, one of the four members comprising the Jak family of cytosolic tyrosine kinases, has emerged as a promising target for nontoxic immunotherapies. Although a number of Jak inhibitors has already demonstrated efficacy, they suffer from secondary effects apparently associated to their pan-Jak activity. However, whether selective Jak3 inhibition would afford therapeutic efficacy remains unclear. To address this question we have investigated the immunosuppressive potential of selective Jak3 intervention in lymphocytes using RNA interference (RNAi) technology in vitro and in vivo. Using synthetic small interference RNA (siRNA) sequences we achieved successful transfections into human and mouse primary T lymphocytes. We found that Jak3 knockdown was sufficient to impair not only interleukin-2 (IL-2) and T cell receptor (TCR)-mediated cell activation in vitro, but also antigen-triggereds welling, inflammatory cell infiltration, and proinflammatory cytokine raise in vivo. Furthermore, Jak1 (which mediates γc cytokine signaling in conjunction with Jak3) cosilencing did not provide higher potency to the aforementioned immunosuppressant effects. Our data provides direct evidences indicating that Jak3 protein plays an important role in γc cytokine and antigen-mediated T cell activation and modulates Th1-mediated inflammatory disorders, all in all highlighting its potential as a target in immunosuppressive therapies.
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34
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Diagnosis and management of acute myeloid leukemia in children and adolescents: recommendations from an international expert panel. Blood 2012; 120:3187-205. [PMID: 22879540 DOI: 10.1182/blood-2012-03-362608] [Citation(s) in RCA: 346] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Despite major improvements in outcome over the past decades, acute myeloid leukemia (AML) remains a life-threatening malignancy in children, with current survival rates of ∼70%. State-of-the-art recommendations in adult AML have recently been published in this journal by Döhner et al. The primary goal of an international expert panel of the International BFM Study Group AML Committee was to set standards for the management, diagnosis, response assessment, and treatment in childhood AML. This paper aims to discuss differences between childhood and adult AML, and to highlight recommendations that are specific to children. The particular relevance of new diagnostic and prognostic molecular markers in pediatric AML is presented. The general management of pediatric AML, the management of specific pediatric AML cohorts (such as infants) or subtypes of the disease occurring in children (such as Down syndrome related AML), as well as new therapeutic approaches, and the role of supportive care are discussed.
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35
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SKLB1028, a novel oral multikinase inhibitor of EGFR, FLT3 and Abl, displays exceptional activity in models of FLT3-driven AML and considerable potency in models of CML harboring Abl mutants. Leukemia 2012; 26:1892-5. [DOI: 10.1038/leu.2012.67] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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36
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Abstract
To identify rational therapeutic combinations with cytarabine (Ara-C), we developed a high-throughput, small-interference RNA (siRNA) platform for myeloid leukemia cells. Of 572 kinases individually silenced in combination with Ara-C, silencing of 10 (1.7%) and 8 (1.4%) kinases strongly increased Ara-C activity in TF-1 and THP-1 cells, respectively. The strongest molecular concepts emerged around kinases involved in cell-cycle checkpoints and DNA-damage repair. In confirmatory siRNA assays, inhibition of WEE1 resulted in more potent and universal sensitization across myeloid cell lines than siRNA inhibition of PKMYT1, CHEK1, or ATR. Treatment of 8 acute myeloid leukemia (AML), acute lymphoblastic leukemia (ALL), and chronic myeloid leukemia (CML) cell lines with commercial and the first-in-class clinical WEE1 kinase inhibitor MK1775 confirmed sensitization to Ara-C up to 97-fold. Ex vivo, adding MK1775 substantially reduced viability in 13 of 14 AML, CML, and myelodysplastic syndrome patient samples compared with Ara-C alone. Maximum sensitization occurred at lower to moderate concentrations of both drugs. Induction of apoptosis was increased using a combination of Ara-C and MK1775 compared with using either drug alone. WEE1 is expressed in primary AML, ALL, and CML specimens. Data from this first siRNA-kinome sensitizer screen suggests that inhibiting WEE1 in combination with Ara-C is a rational combination for the treatment of myeloid and lymphoid leukemias.
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37
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Efficacy of NS-018, a potent and selective JAK2/Src inhibitor, in primary cells and mouse models of myeloproliferative neoplasms. Blood Cancer J 2011; 1:e29. [PMID: 22829185 PMCID: PMC3255248 DOI: 10.1038/bcj.2011.29] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2011] [Accepted: 06/15/2011] [Indexed: 12/15/2022] Open
Abstract
Aberrant activation of Janus kinase 2 (JAK2) caused by somatic mutation of JAK2 (JAK2V617F) or the thrombopoietin receptor (MPLW515L) plays an essential role in the pathogenesis of myeloproliferative neoplasms (MPNs), suggesting that inhibition of aberrant JAK2 activation would have a therapeutic benefit. Our novel JAK2 inhibitor, NS-018, was highly active against JAK2 with a 50% inhibition (IC50) of <1 n, and had 30–50-fold greater selectivity for JAK2 over other JAK-family kinases, such as JAK1, JAK3 and tyrosine kinase 2. In addition to JAK2, NS-018 inhibited Src-family kinases. NS-018 showed potent antiproliferative activity against cell lines expressing a constitutively activated JAK2 (the JAK2V617F or MPLW515L mutations or the TEL–JAK2 fusion gene; IC50=11–120 n), but showed only minimal cytotoxicity against most other hematopoietic cell lines without a constitutively activated JAK2. Furthermore, NS-018 preferentially suppressed in vitro erythropoietin-independent endogenous colony formation from polycythemia vera patients. NS-018 also markedly reduced splenomegaly and prolonged the survival of mice inoculated with Ba/F3 cells harboring JAK2V617F. In addition, NS-018 significantly reduced leukocytosis, hepatosplenomegaly and extramedullary hematopoiesis, improved nutritional status, and prolonged survival in JAK2V617F transgenic mice. These results suggest that NS-018 will be a promising candidate for the treatment of MPNs.
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Focal adhesion kinase as a target in the treatment of hematological malignancies. Leuk Res 2011; 35:1416-8. [PMID: 21592572 DOI: 10.1016/j.leukres.2011.04.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2011] [Revised: 04/11/2011] [Accepted: 04/16/2011] [Indexed: 11/23/2022]
Abstract
Focal adhesion kinase (FAK) is a non-receptor protein tyrosine kinase that plays important regulatory roles in several basic cellular activities. During normal development, FAK is a critical mediator of the integrin signaling cascade, which modulates cell proliferation, apoptosis, adhesion, spreading and migration. Importantly, FAK overexpression is found in a large number of cancer types and FAK expression levels generally correlate with increased tumor malignancy. Though FAK has been a popular potential target for treatment of solid tumors, its roles in leukemias and lymphomas have not been well defined. Here, I briefly summarize the multifaceted functions of FAK in tumor progression, and discuss current efforts and exciting future directions of using RNAi-mediated knockdown of FAK as a potential therapy against leukemia and lymphomas.
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Katsumi A, Kiyoi H, Abe A, Tanizaki R, Iwasaki T, Kobayashi M, Matsushita T, Kaibuchi K, Senga T, Kojima T, Kohno T, Hamaguchi M, Naoe T. FLT3/ ITD regulates leukaemia cell adhesion through α4β1 integrin and Pyk2 signalling. Eur J Haematol 2011; 86:191-8. [PMID: 21114537 DOI: 10.1111/j.1600-0609.2010.01556.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Internal tandem duplication of FMS-like receptor tyrosine kinase 3 (FLT3/ITD) within its juxtamembrane domain is a frequent mutation in adult acute myeloid leukaemia (AML). This mutation causes constitutive activation of FLT3 and is associated with poor prognosis. The high relapse rate of FLT3/ITD-positive AML might be partly because of insufficient eradication of slow-cycling leukaemic stem cells in the bone marrow microenvironment. β1 integrin mediates haematopoietic stem and progenitor cell homing along with their retention in the bone marrow and also inhibits haematopoietic proliferation and differentiation. Here, we demonstrate that inhibition of FLT3/ITD kinase activity by a FLT3 selective inhibitor named FI-700 decreases affinity of α4β1 integrin to soluble VCAM-1. α4β1 integrin deactivation by FI-700 is independent of Rap1, which is the critical regulator of integrin inside-out signalling. In addition, selective inhibition of FLT3/ITD induces Pyk2 dephosphorylation together with the inhibition of phosphatidylinositol-3-kinase (PI3K)/Akt pathway. Both wild-type and ITD-FLT3 proteins co-immunoprecipitated with β1 integrin and Pyk2 indicating the signal crosstalk between FLT3, β1 integrin and Pyk2. These results collectively indicated that the inhibition of FLT3 kinase might contribute not only to the induction of apoptosis, but also to the leukaemia cell detachment from the bone marrow microenvironment in the treatment of AML.
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Affiliation(s)
- Akira Katsumi
- Division of Transfusion Medicine and Cell Therapy, National Center for Geriatrics and Gerontology, 35 Gengo, Morioka-cho, Obu 474-8511, Japan.
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40
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Xu LH, Fang JP, Weng WJ, Xu HG, Le Y. WITHDRAWN: Therapeutic efficacy of focal adhesion kinase downregulation in REH cells by RNA interference. Leuk Res 2010:S0145-2126(10)00580-1. [PMID: 21176958 DOI: 10.1016/j.leukres.2010.12.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2010] [Revised: 11/29/2010] [Accepted: 12/02/2010] [Indexed: 11/20/2022]
Abstract
This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.
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Affiliation(s)
- Lu-Hong Xu
- Department of Pediatrics, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China; Department of Pathology, Joint Program in Transfusion Medicine, Children's Hospital Boston, Boston, MA, USA
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41
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Chaix A, Lopez S, Voisset E, Gros L, Dubreuil P, De Sepulveda P. Mechanisms of STAT protein activation by oncogenic KIT mutants in neoplastic mast cells. J Biol Chem 2010; 286:5956-66. [PMID: 21135090 DOI: 10.1074/jbc.m110.182642] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mutations in the c-kit gene occur in the vast majority of mastocytosis. In adult patients as well as in the cell line derived from mast cell neoplasms, the mutations occur almost exclusively at amino acid 816 within the kinase domain of KIT. Among the downstream effectors of KIT signaling, STAT3 and STAT5 have been shown to be critical for cell proliferation elicited by the KIT-Asp(816) mutant protein. However, little is known about the mechanisms of activation of STAT proteins. In this study, we identify and clarify the contribution of various STAT kinases in two widely used neoplastic mast cell lines, P815 and HMC-1. We show that STAT1, -3, and -5 proteins are activated downstream of the KIT-Asp(816) mutant. All three STAT proteins are located in the nucleus and are phosphorylated on serine residues. KIT-Asp(816) mutant can directly phosphorylate STATs on the activation-specific tyrosine residues in vitro. However, within cells, SRC family kinases and JAKs diversely contribute to tyrosine phosphorylation of STAT proteins downstream of the KIT mutant. Using a panel of inhibitors, we provide evidence for the implication or exclusion of serine/threonine kinases as responsible for serine phosphorylation of STAT1, -3, and -5 in the two cell lines. Finally, we show that only STAT5 is transcriptionally active in these cells. This suggests that the contribution of STAT1 and STAT3 downstream of KIT mutant is independent of their transcription factor function.
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Affiliation(s)
- Amandine Chaix
- INSERM, U891, Centre de Recherche en Cancérologie de Marseille, France
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42
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Ter Elst A, Diks SH, Kampen KR, Hoogerbrugge PM, Ruijtenbeek R, Boender PJ, Sikkema AH, Scherpen FJG, Kamps WA, Peppelenbosch MP, de Bont ESJM. Identification of new possible targets for leukemia treatment by kinase activity profiling. Leuk Lymphoma 2010; 52:122-30. [PMID: 21133721 DOI: 10.3109/10428194.2010.535181] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
To date, the biology of acute leukemia has been unclear, and defining new therapeutic targets without prior knowledge remains complicated. The use of high-throughput techniques would enable us to learn more about the biology of the disease, and make it possible to directly assess a broader range of therapeutic targets. In this study we have identified comprehensive tyrosine kinase activity profiles in leukemia samples using the PamChip® kinase activity profiling system. Strikingly, 31% (44/120) of the detected peptides were active in all three groups of leukemia samples. The recently reported activity of platelet-derived growth factor receptor (PDGFR) and neurotrophic tyrosine kinase receptors (NTRK1 and NTRK2) in leukemia could be appreciated in our array results. In addition, high levels of peptide phosphorylation were demonstrated for peptides related to macrophage stimulating 1 receptor (MST1R). A provisional signal transduction scheme of the common active peptides was constructed and used to specifically select an inhibitor for leukemic blast cell survival assays. As expected, a dose-dependent decrease in leukemic blast cell survival was achieved for all leukemia samples. Our data demonstrate that kinase activity profiling in leukemic samples is feasible and provides novel insights into the pathogenesis of leukemia. This approach can be used for the rapid discovery of potential drug targets.
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Affiliation(s)
- Arja Ter Elst
- Department of Pediatric Oncology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
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43
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Qian J, Qian Z, Lin J, Yao DM, Chen Q, Li Y, Ji RB, Yang J, Xiao GF, Wang YL. Abnormal methylation of GRAF promoter Chinese patients with acute myeloid leukemia. Leuk Res 2010; 35:783-6. [PMID: 21074269 DOI: 10.1016/j.leukres.2010.10.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2010] [Revised: 10/01/2010] [Accepted: 10/17/2010] [Indexed: 10/18/2022]
Abstract
The epigenetic disturbances are recognized as an alternative mechanism contributing to the pathogenesis of acute myeloid leukemia (AML). GTPase regulator associated with focal adhesion kinase (GRAF), a putative tumor suppressor gene, was revealed with mutations and promoter methylation in AML and myelodysplastic syndrome. In this study, we investigated the methylation status of GRAF promoter in Chinese AML patients. Aberrant methylation of GRAF promoter was detected in 66.7% (88/132) of the cases analyzed. The methylation of GRAF gene could be detected in all FAB subtypes and in all cytogenetic risk groups. There were no significant differences in clinical features, FAB subtypes and cytogenetic risk groups between patients with and without GRAF methylation. GRAF transcript was significantly lower in AML group compared to controls (3.30 vs 56.06, P<0.001). Both patients with methylated GRAF gene and those without methylated GRAF gene had significantly lower GRAF transcript than controls (P<0.001). Furthermore, GRAF transcript was significantly lower in patients with methylated GRAF than those without methylated GRAF (1.64 vs 6.42, P=0.005). These findings suggest that the hypermethylation of GRAF promoter might be one of early events in the development of AML.
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Affiliation(s)
- Jun Qian
- Department of Hematology, Affiliated People's Hospital of Jiangsu University, Zhenjiang, China
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Qian Z, Qian J, Lin J, Yao DM, Chen Q, Ji RB, Li Y, Xiao GF, Li JY. GTPase regulator associated with the focal adhesion kinase (GRAF) transcript was down-regulated in patients with myeloid malignancies. JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH : CR 2010; 29:111. [PMID: 20704716 PMCID: PMC2927506 DOI: 10.1186/1756-9966-29-111] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2010] [Accepted: 08/12/2010] [Indexed: 11/10/2022]
Abstract
BACKGROUND GTPase regulator associated with the focal adhesion kinase (GRAF), a putative tumor suppressor gene, is found inactivated in hematopoietic malignancies by either genetic or epigenetic abnormalities. However, the expression level of GRAF gene has not yet been studied in leukemia. The aim of this study was to investigate the expression level of GRAF gene in those patients with myeloid malignancies including acute myeloid leukemia (AML), myelodysplastic syndrome (MDS) and chronic myeloid leukemia (CML). METHODS The expression levels of GRAF transcript were determined in 94 patients using real-time quantitative PCR (RQ-PCR). Clinical and laboratory data of these patients were collected and analyzed. RESULTS The significantly decreased level of GRAF transcript was observed in three myeloid malignancies compared to controls. Within AML, there was no difference in the level of GRAF transcript among different FAB subtypes (P > 0.05). Difference was not observed in the amount of GRAF mRNA between CML at chronic phase and controls. As CML progressed, GRAF transcript significantly decreased. In MDS, three cases with 5q deletion had lower GRAF transcript than four without 5q deletion (median 0.76 vs 2.99) (P > 0.05). CONCLUSION our results demonstrate that the GRAF transcript is decreased in myeloid malignancies.
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Affiliation(s)
- Zhen Qian
- Department of Hematology, Affiliated People's Hospital of Jiangsu University, Zhenjiang, Jiangsu 212002, China.
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Zhang J, Mendoza M, Guiraldelli MF, Barbu EA, Siraganian RP. Small interfering RNA screen for phosphatases involved in IgE-mediated mast cell degranulation. THE JOURNAL OF IMMUNOLOGY 2010; 184:7178-85. [PMID: 20483767 DOI: 10.4049/jimmunol.0904169] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Mast cells play pivotal roles in the initiation of the allergic response. To gain an understanding of the functions played by phosphatases in IgE-mediated mast cell activation, a small interfering RNA (siRNA) library that targets all mouse phosphatase genes was screened in a mouse mast cell line, MMC-1. Of 198 targets, 10 enhanced and 7 inhibited FcepsilonRI-induced degranulation. For seven of the strongest hits, four different siRNAs per target were tested, and at least two out of the four single siRNA per target had similar effects as the pool suggesting that these were true hits. Bone marrow-derived mast cells from normal mice further validated these results for six definite positive targets. The mechanism of the reduced mast cell degranulation due to calcineurin B deficiency was investigated. Calcineurin B deficiency reduced the phosphorylation of MAPKs and the phosphorylation of protein kinase D/protein kinase Cmu and protein kinase Cdelta, which are involved in FcepsilonRI signaling. The screen, therefore, has identified several new molecules that are critical for FcepsilonRI-induced degranulation. Regulating the function of these proteins may be potential targets for the treatment of allergic inflammation. The result also indicates that the system used is efficient for searching molecules implicated in complex receptor-induced signaling.
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Affiliation(s)
- Juan Zhang
- Receptors and Signal Transduction Section, Oral Infection and Immunity Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20892, USA
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CYT387, a novel JAK2 inhibitor, induces hematologic responses and normalizes inflammatory cytokines in murine myeloproliferative neoplasms. Blood 2010; 115:5232-40. [PMID: 20385788 DOI: 10.1182/blood-2009-05-223727] [Citation(s) in RCA: 185] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Activating alleles of Janus kinase 2 (JAK2) such as JAK2(V617F) are central to the pathogenesis of myeloproliferative neoplasms (MPN), suggesting that small molecule inhibitors targeting JAK2 may be therapeutically useful. We have identified an aminopyrimidine derivative (CYT387), which inhibits JAK1, JAK2, and tyrosine kinase 2 (TYK2) at low nanomolar concentrations, with few additional targets. Between 0.5 and 1.5muM CYT387 caused growth suppression and apoptosis in JAK2-dependent hematopoietic cell lines, while nonhematopoietic cell lines were unaffected. In a murine MPN model, CYT387 normalized white cell counts, hematocrit, spleen size, and restored physiologic levels of inflammatory cytokines. Despite the hematologic responses and reduction of the JAK2(V617F) allele burden, JAK2(V617F) cells persisted and MPN recurred upon cessation of treatment, suggesting that JAK2 inhibitors may be unable to eliminate JAK2(V617F) cells, consistent with preliminary results from clinical trials of JAK2 inhibitors in myelofibrosis. While the clinical benefit of JAK2 inhibitors may be substantial, not the least due to reduction of inflammatory cytokines and symptomatic improvement, our data add to increasing evidence that kinase inhibitor monotherapy of malignant disease is not curative, suggesting a need for drug combinations to optimally target the malignant cells.
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Haan C, Behrmann I, Haan S. Perspectives for the use of structural information and chemical genetics to develop inhibitors of Janus kinases. J Cell Mol Med 2010; 14:504-27. [PMID: 20132407 PMCID: PMC3823453 DOI: 10.1111/j.1582-4934.2010.01018.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Gain-of-function mutations in the genes encoding Janus kinases have been discovered in various haematologic diseases. Jaks are composed of a FERM domain, an SH2 domain, a pseudokinase domain and a kinase domain, and a complex interplay of the Jak domains is involved in regulation of catalytic activity and association to cytokine receptors. Most activating mutations are found in the pseudokinase domain. Here we present recently discovered mutations in the context of our structural models of the respective domains. We describe two structural hotspots in the pseudokinase domain of Jak2 that seem to be associated either to myeloproliferation or to lymphoblastic leukaemia, pointing at the involvement of distinct signalling complexes in these disease settings. The different domains of Jaks are discussed as potential drug targets. We present currently available inhibitors targeting Jaks and indicate structural differences in the kinase domains of the different Jaks that may be exploited in the development of specific inhibitors. Moreover, we discuss recent chemical genetic approaches which can be applied to Jaks to better understand the role of these kinases in their biological settings and as drug targets.
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Affiliation(s)
- Claude Haan
- Life Sciences Research Unit, University of Luxembourg, 162A, av. de la Faïencerie, 1511 Luxembourg, Luxembourg.
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Jiang J, McDonald PR, Dixon TM, Franicola D, Zhang X, Nie S, Epperly LD, Huang Z, Kagan VE, Lazo JS, Epperly MW, Greenberger JS. Synthetic protection short interfering RNA screen reveals glyburide as a novel radioprotector. Radiat Res 2009; 172:414-22. [PMID: 19772462 DOI: 10.1667/rr1674.1] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
To assist in screening existing drugs for use as potential radioprotectors, we used a human unbiased 16,560 short interfering RNA (siRNA) library targeting the druggable genome. We performed a synthetic protection screen that was designed to identify genes that, when silenced, protected human glioblastoma T98G cells from gamma-radiation-induced cell death. We identified 116 candidate protective genes, then identified 10 small molecule inhibitors of 13 of these candidate gene products and tested their radioprotective effects. Glyburide, a clinically used second-generation hypoglycemic drug, effectively decreased radiation-induced cell death in several cell lines including T98G, glioblastoma U-87 MG, and normal lung epithelial BEAS-2B and in primary cultures of astrocytes. Glyburide significantly increased the survival of 32D cl3 murine hematopoietic progenitor cells when administrated before irradiation. Glyburide was radioprotective in vivo (90% of C57BL/6NHsd female mice pretreated with 10 mg/kg glyburide survived 9.5 Gy total-body irradiation compared to 42% of irradiated controls, P = 0.0249). These results demonstrate the power of unbiased siRNA synthetic protection screening with a druggable genome library to identify new radioprotectors.
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Affiliation(s)
- Jianfei Jiang
- Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
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Murrow LM, Garimella SV, Jones TL, Caplen NJ, Lipkowitz S. Identification of WEE1 as a potential molecular target in cancer cells by RNAi screening of the human tyrosine kinome. Breast Cancer Res Treat 2009; 122:347-57. [PMID: 19821025 DOI: 10.1007/s10549-009-0571-2] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2009] [Accepted: 09/21/2009] [Indexed: 11/26/2022]
Abstract
Breast cancers can be classified into those that express the estrogen (ER) and progesterone (PR) receptors, those with ERBB2 (HER-2/Neu) amplification, and those without expression of ER, PR, or amplification of ERBB2 (referred to as triple-negative or basal-like breast cancer). In order to identify potential molecular targets in breast cancer, we performed a synthetic siRNA-mediated RNAi screen of the human tyrosine kinome. A primary RNAi screen conducted in the triple-negative/basal-like breast cancer cell line MDA-MB231 followed by secondary RNAi screens and further studies in this cell line and two additional triple-negative/basal-like breast cancer cell lines, BT20 and HCC1937, identified the G2/M checkpoint protein, WEE1, as a potential therapeutic target. Similar sensitivity to WEE1 inhibition was observed in cell lines from all subtypes of breast cancer. RNAi-mediated silencing or small compound inhibition of WEE1 in breast cancer cell lines resulted in an increase in gammaH2AX levels, arrest in the S-phase of the cell cycle, and a significant decrease in cell proliferation. WEE1-inhibited cells underwent apoptosis as demonstrated by positive Annexin V staining, increased sub-G1 DNA content, apoptotic morphology, caspase activation, and rescue by the pan-caspase inhibitor, Z-VAD-FMK. In contrast, the non-transformed mammary epithelial cell line, MCF10A, did not exhibit any of these downstream effects following WEE1 silencing or inhibition. These results identify WEE1 as a potential molecular target in breast cancer.
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Affiliation(s)
- Lyndsay M Murrow
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, 37 Convent Drive, Bethesda, MD 20892-4256, USA
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Hess JL. What hematopathology tells us about the future of pathology informatics. Arch Pathol Lab Med 2009; 133:908-11. [PMID: 19492882 DOI: 10.5858/133.6.908] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/29/2008] [Indexed: 11/06/2022]
Abstract
The field of hematopathology has been a leader in the application of new technologies for both diagnostics and therapy. The ready accessibility of blood cells for examination, the ability to quantify important indices, and the relative responsiveness of otherwise fatal hematologic diseases to chemotherapy have all contributed to rapid advances in the field. Hematopathology provides many insights into the challenges that pathology informatics will face in addressing the needs of a growing and aging population in the era of personalized medicine.
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Affiliation(s)
- Jay L Hess
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109-5602, USA.
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