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Eilers G, Gupta K, Allen A, Montermoso S, Murali H, Sharp R, Hwang Y, Bushman FD, Van Duyne G. Structure of a HIV-1 IN-Allosteric inhibitor complex at 2.93 Å resolution: Routes to inhibitor optimization. PLoS Pathog 2023; 19:e1011097. [PMID: 36867659 PMCID: PMC10016701 DOI: 10.1371/journal.ppat.1011097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 03/15/2023] [Accepted: 01/03/2023] [Indexed: 03/04/2023] Open
Abstract
HIV integrase (IN) inserts viral DNA into the host genome and is the target of the strand transfer inhibitors (STIs), a class of small molecules currently in clinical use. Another potent class of antivirals is the allosteric inhibitors of integrase, or ALLINIs. ALLINIs promote IN aggregation by stabilizing an interaction between the catalytic core domain (CCD) and carboxy-terminal domain (CTD) that undermines viral particle formation in late replication. Ongoing challenges with inhibitor potency, toxicity, and viral resistance motivate research to understand their mechanism. Here, we report a 2.93 Å X-ray crystal structure of the minimal ternary complex between CCD, CTD, and the ALLINI BI-224436. This structure reveals an asymmetric ternary complex with a prominent network of π-mediated interactions that suggest specific avenues for future ALLINI development and optimization.
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Affiliation(s)
- Grant Eilers
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Kushol Gupta
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Audrey Allen
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Saira Montermoso
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Hemma Murali
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Robert Sharp
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Young Hwang
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Frederic D. Bushman
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Gregory Van Duyne
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
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Gupta K, Eilers G, Allen A, Montermoso S, Murali H, Sharp R, Hwang Y, Bushman F, Van Duyne G. Structure of an HIV-1 IN-allosteric inhibitor complex at 2.93 Å resolution: routes to inhibitor optimization. Acta Crystallogr A Found Adv 2022. [DOI: 10.1107/s2053273322099867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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3
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Gupta K, Allen A, Giraldo C, Eilers G, Sharp R, Hwang Y, Murali H, Cruz K, Janmey P, Bushman F, Van Duyne GD. Allosteric HIV Integrase Inhibitors Promote Formation of Inactive Branched Polymers via Homomeric Carboxy-Terminal Domain Interactions. Structure 2021; 29:213-225.e5. [PMID: 33357410 PMCID: PMC7935764 DOI: 10.1016/j.str.2020.12.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 11/04/2020] [Accepted: 12/04/2020] [Indexed: 12/12/2022]
Abstract
The major effect of allosteric HIV integrase (IN) inhibitors (ALLINIs) is observed during virion maturation, where ALLINI treatment interrupts IN-RNA interactions via drug-induced IN aggregation, leading to the formation of aberrant virions. To understand the structural changes that accompany drug-induced aggregation, we determined the soft matter properties of ALLINI-induced IN aggregates. Using small-angle neutron scattering, SEM, and rheology, we have discovered that the higher-order aggregates induced by ALLINIs have the characteristics of weak three-dimensional gels with a fractal-like character. Their formation is inhibited by the host factor LEDGF/p75, as well as ex vivo resistance substitutions. Mutagenesis and biophysical analyses reveal that homomeric carboxy-terminal domain interactions are required to achieve the branched-polymer nature of the ALLINI-induced aggregates. These studies provide key insight into the mechanisms of ALLINI action and resistance in the context of the crowded virion environment where ALLINIs exert their effect.
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Affiliation(s)
- Kushol Gupta
- Department of Biochemistry & Biophysics, Perelman School of Medicine, University of Pennsylvania, 809C Stellar-Chance Building, 422 Curie Boulevard, Philadelphia, PA 19105-6059, USA
| | - Audrey Allen
- Department of Microbiology, University of Pennsylvania School of Medicine, 426 Johnson Pavilion, 3610 Hamilton Walk, Philadelphia, PA 19104-6076, USA
| | - Carolina Giraldo
- Department of Biochemistry & Biophysics, Perelman School of Medicine, University of Pennsylvania, 809C Stellar-Chance Building, 422 Curie Boulevard, Philadelphia, PA 19105-6059, USA
| | - Grant Eilers
- Department of Microbiology, University of Pennsylvania School of Medicine, 426 Johnson Pavilion, 3610 Hamilton Walk, Philadelphia, PA 19104-6076, USA
| | - Robert Sharp
- Department of Biochemistry & Biophysics, Perelman School of Medicine, University of Pennsylvania, 809C Stellar-Chance Building, 422 Curie Boulevard, Philadelphia, PA 19105-6059, USA
| | - Young Hwang
- Department of Microbiology, University of Pennsylvania School of Medicine, 426 Johnson Pavilion, 3610 Hamilton Walk, Philadelphia, PA 19104-6076, USA
| | - Hemma Murali
- Department of Biochemistry & Biophysics, Perelman School of Medicine, University of Pennsylvania, 809C Stellar-Chance Building, 422 Curie Boulevard, Philadelphia, PA 19105-6059, USA
| | - Katrina Cruz
- Department of Physiology, and Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, PA 19104-6383, USA
| | - Paul Janmey
- Department of Physiology, and Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, PA 19104-6383, USA
| | - Frederic Bushman
- Department of Microbiology, University of Pennsylvania School of Medicine, 426 Johnson Pavilion, 3610 Hamilton Walk, Philadelphia, PA 19104-6076, USA.
| | - Gregory D Van Duyne
- Department of Biochemistry & Biophysics, Perelman School of Medicine, University of Pennsylvania, 809C Stellar-Chance Building, 422 Curie Boulevard, Philadelphia, PA 19105-6059, USA.
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Ou WB, Ni N, Zuo R, Zhuang W, Zhu M, Kyriazoglou A, Wu D, Eilers G, Demetri GD, Qiu H, Li B, Marino-Enriquez A, Fletcher JA. Cyclin D1 is a mediator of gastrointestinal stromal tumor KIT-independence. Oncogene 2019; 38:6615-6629. [PMID: 31371779 DOI: 10.1038/s41388-019-0894-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 02/22/2019] [Accepted: 04/03/2019] [Indexed: 12/19/2022]
Abstract
Oncogenic KIT or PDGFRA tyrosine kinase mutations are compelling therapeutic targets in most gastrointestinal stromal tumors (GISTs), and the KIT inhibitor, imatinib, is therefore standard of care for patients with metastatic GIST. However, some GISTs lose expression of KIT oncoproteins, and therefore become KIT-independent and are consequently resistant to KIT-inhibitor drugs. We identified distinctive biologic features in KIT-independent, imatinib-resistant GISTs as a step towards identifying drug targets in these poorly understood tumors. We developed isogenic GIST lines in which the parental forms were KIT oncoprotein-dependent, whereas sublines had loss of KIT oncoprotein expression, accompanied by markedly downregulated expression of the GIST biomarker, protein kinase C-theta (PRKCQ). Biologic mechanisms unique to KIT-independent GISTs were identified by transcriptome sequencing, qRT-PCR, immunoblotting, protein interaction studies, knockdown and expression assays, and dual-luciferase assays. Transcriptome sequencing showed that cyclin D1 expression was extremely low in two of three parental KIT-dependent GIST lines, whereas cyclin D1 expression was high in each of the KIT-independent GIST sublines. Cyclin D1 inhibition in KIT-independent GISTs had anti-proliferative and pro-apoptotic effects, associated with Rb activation and p27 upregulation. PRKCQ, but not KIT, was a negative regulator of cyclin D1 expression, whereas JUN and Hippo pathway effectors YAP and TAZ were positive regulators of cyclin D1 expression. PRKCQ, JUN, and the Hippo pathway coordinately regulate GIST cyclin D1 expression. These findings highlight the roles of PRKCQ, JUN, Hippo, and cyclin D1 as oncogenic mediators in GISTs that have converted, during TKI-therapy, to a KIT-independent state. Inhibitors of these pathways could be effective therapeutically for these now untreatable tumors.
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Affiliation(s)
- Wen-Bin Ou
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, Zhejiang, China. .,Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, 02115, USA.
| | - Nan Ni
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, Zhejiang, China
| | - Rui Zuo
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, Zhejiang, China
| | - Weihao Zhuang
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, Zhejiang, China
| | - Meijun Zhu
- Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, 02115, USA
| | - Anastasios Kyriazoglou
- Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, 02115, USA
| | - Duolin Wu
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, Zhejiang, China
| | - Grant Eilers
- Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, 02115, USA
| | - George D Demetri
- Ludwig Center at Dana-Farber/Harvard Cancer Center and Department of Medical Oncology, Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA, 02115, USA
| | - Haibo Qiu
- Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, 02115, USA.,State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Bin Li
- Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, 02115, USA.,Division of Oncology, Xiangya Hospital, Central South University, Changsha, China
| | - Adrian Marino-Enriquez
- Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, 02115, USA
| | - Jonathan A Fletcher
- Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, 02115, USA.
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Gupta K, Eilers G, Allen A, Giraldo C, Sharp B, Hwang Y, Cruz K, Jamney P, Bushman FD, Van Duyne GD. Higher-order structures of HIV integrase: drug-induced aggregates of HIV integrase are weak gels. Acta Crystallogr A Found Adv 2019. [DOI: 10.1107/s0108767319097393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Serrano C, Mariño-Enríquez A, Tao DL, Ketzer J, Eilers G, Zhu M, Yu C, Mannan AM, Rubin BP, Demetri GD, Raut CP, Presnell A, McKinley A, Heinrich MC, Czaplinski JT, Sicinska E, Bauer S, George S, Fletcher JA. Correction: Complementary activity of tyrosine kinase inhibitors against secondary kit mutations in imatinib-resistant gastrointestinal stromal tumours. Br J Cancer 2019; 121:281. [PMID: 31123346 PMCID: PMC6738067 DOI: 10.1038/s41416-019-0487-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Affiliation(s)
- César Serrano
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, 20 Shattuck Street, Thorn 528, Boston, MA, USA. .,Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA. .,Sarcoma Translational Research Laboratory, Vall d'Hebron Institute of Oncology; Department of Oncology, Vall d'Hebron University Hospital, Barcelona, Spain.
| | - Adrián Mariño-Enríquez
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, 20 Shattuck Street, Thorn 528, Boston, MA, USA
| | - Derrick L Tao
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, 20 Shattuck Street, Thorn 528, Boston, MA, USA
| | - Julia Ketzer
- Department of Medical Oncology, West German Cancer Center, University Hospital Essen, University Duisburg-Essen, Essen, Germany
| | - Grant Eilers
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, 20 Shattuck Street, Thorn 528, Boston, MA, USA
| | - Meijun Zhu
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, 20 Shattuck Street, Thorn 528, Boston, MA, USA
| | - Channing Yu
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA.,Broad Institute of MIT and Harvard, 7 Cambridge Center, Cambridge, MA, USA.,Daiichi Sankyo Inc., Basking Ridge, NJ, USA
| | - Aristotle M Mannan
- Broad Institute of MIT and Harvard, 7 Cambridge Center, Cambridge, MA, USA
| | - Brian P Rubin
- Department of Molecular Genetics, Lerner Research Institute and Cleveland Clinic, 9500, Euclid Ave, Cleveland, OH, USA
| | - George D Demetri
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA.,Ludwig Center for Cancer Research at Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA, USA
| | - Chandrajit P Raut
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA.,Division of Surgical Oncology, Brigham and Women's Hospital, Harvard Medical School, Boston, 75 Francis Street, Boston, MA, USA
| | - Ajia Presnell
- Portland VA Medical Center and OHSU Knight Cancer Institute, Portland, Oregon, USA
| | - Arin McKinley
- Portland VA Medical Center and OHSU Knight Cancer Institute, Portland, Oregon, USA
| | - Michael C Heinrich
- Portland VA Medical Center and OHSU Knight Cancer Institute, Portland, Oregon, USA
| | | | - Ewa Sicinska
- Department of Oncologic Pathology, Dana Farber Cancer Institute, Boston, MA, USA
| | - Sebastian Bauer
- Department of Medical Oncology, West German Cancer Center, University Hospital Essen, University Duisburg-Essen, Essen, Germany
| | - Suzanne George
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Jonathan A Fletcher
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, 20 Shattuck Street, Thorn 528, Boston, MA, USA. .,Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA.
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7
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Serrano C, Mariño-Enríquez A, Tao DL, Ketzer J, Eilers G, Zhu M, Yu C, Mannan AM, Rubin BP, Demetri GD, Raut CP, Presnell A, McKinley A, Heinrich MC, Czaplinski JT, Sicinska E, Bauer S, George S, Fletcher JA. Complementary activity of tyrosine kinase inhibitors against secondary kit mutations in imatinib-resistant gastrointestinal stromal tumours. Br J Cancer 2019; 120:612-620. [PMID: 30792533 PMCID: PMC6462042 DOI: 10.1038/s41416-019-0389-6] [Citation(s) in RCA: 88] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 09/28/2018] [Accepted: 10/22/2018] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Most patients with KIT-mutant gastrointestinal stromal tumours (GISTs) benefit from imatinib, but treatment resistance results from outgrowth of heterogeneous subclones with KIT secondary mutations. Once resistance emerges, targeting KIT with tyrosine kinase inhibitors (TKIs) sunitinib and regorafenib provides clinical benefit, albeit of limited duration. METHODS We systematically explored GIST resistance mechanisms to KIT-inhibitor TKIs that are either approved or under investigation in clinical trials: the studies draw upon GIST models and clinical trial correlative science. We subsequently modelled in vitro a rapid TKI alternation approach against subclonal heterogeneity. RESULTS Each of the KIT-inhibitor TKIs targets effectively only a subset of KIT secondary mutations in GIST. Regorafenib and sunitinib have complementary activity in that regorafenib primarily inhibits imatinib-resistance mutations in the activation loop, whereas sunitinib inhibits imatinib-resistance mutations in the ATP-binding pocket. We find that rapid alternation of sunitinib and regorafenib suppresses growth of polyclonal imatinib-resistant GIST more effectively than either agent as monotherapy. CONCLUSIONS Our data highlight that heterogeneity of KIT secondary mutations is the main mechanism of tumour progression to KIT inhibitors in imatinib-resistant GIST patients. Therapeutic combinations of TKIs with complementary activity against resistant mutations may be useful to suppress growth of polyclonal imatinib-resistance in GIST.
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Affiliation(s)
- César Serrano
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, 20 Shattuck Street, Thorn 528, Boston, MA, USA.
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA.
- Sarcoma Translational Research Laboratory, Vall d'Hebron Institute of Oncology; Department of Oncology, Vall d'Hebron University Hospital, Barcelona, Spain.
| | - Adrián Mariño-Enríquez
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, 20 Shattuck Street, Thorn 528, Boston, MA, USA
| | - Derrick L Tao
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, 20 Shattuck Street, Thorn 528, Boston, MA, USA
| | - Julia Ketzer
- Department of Medical Oncology, West German Cancer Center, University Hospital Essen, University Duisburg-Essen, Essen, Germany
| | - Grant Eilers
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, 20 Shattuck Street, Thorn 528, Boston, MA, USA
| | - Meijun Zhu
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, 20 Shattuck Street, Thorn 528, Boston, MA, USA
| | - Channing Yu
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
- Broad Institute of MIT and Harvard, 7 Cambridge Center, Cambridge, MA, USA
- Daiichi Sankyo Inc., Basking Ridge, NJ, USA
| | - Aristotle M Mannan
- Broad Institute of MIT and Harvard, 7 Cambridge Center, Cambridge, MA, USA
| | - Brian P Rubin
- Department of Molecular Genetics, Lerner Research Institute and Cleveland Clinic, 9500 Euclid Ave, Cleveland, OH, USA
| | - George D Demetri
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
- Ludwig Center for Cancer Research at Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA, USA
| | - Chandrajit P Raut
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
- Division of Surgical Oncology, Brigham and Women's Hospital, Harvard Medical School, Boston, 75 Francis Street, Boston, MA, USA
| | - Ajia Presnell
- Portland VA Medical Center and OHSU Knight Cancer Institute, Portland, Oregon, USA
| | - Arin McKinley
- Portland VA Medical Center and OHSU Knight Cancer Institute, Portland, Oregon, USA
| | - Michael C Heinrich
- Portland VA Medical Center and OHSU Knight Cancer Institute, Portland, Oregon, USA
| | | | - Ewa Sicinska
- Department of Oncologic Pathology, Dana Farber Cancer Institute, Boston, MA, USA
| | - Sebastian Bauer
- Department of Medical Oncology, West German Cancer Center, University Hospital Essen, University Duisburg-Essen, Essen, Germany
| | - Suzanne George
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Jonathan A Fletcher
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, 20 Shattuck Street, Thorn 528, Boston, MA, USA.
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA.
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Tu Y, Zuo R, Ni N, Eilers G, Wu D, Pei Y, Nie Z, Wu Y, Wu Y, Ou WB. Activated tyrosine kinases in gastrointestinal stromal tumor with loss of KIT oncoprotein expression. Cell Cycle 2018; 17:2577-2592. [PMID: 30488756 PMCID: PMC6300111 DOI: 10.1080/15384101.2018.1553335] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Oncogenic KIT or PDGFRA receptor tyrosine kinase (TK) mutations are compelling therapeutic targets in gastrointestinal stromal tumors (GISTs), and the KIT/PDGFRA kinase inhibitor, imatinib, is the standard of care for patients with metastatic GIST. However, approximately 10% of KIT-positive GIST metastases lose KIT expression at the time of clinical progression during imatinib therapy. In the present report, we performed TK-activation screens, using phosphotyrosine-TK double immunoaffinity purification and mass spectrometry, in GIST in vitro models lacking KIT expression. These studies demonstrated tyrosine-phosphorylated EGFR, AXL, and EPHA2 in four of six KIT-negative GIST lines (GIST62, GIST522, GIST54, GIST226, GIST48B, and GIST430B), and tyrosine-phosphorylated focal adhesion kinase (FAK) in each of the six KIT-negative lines. AXL expression was strong in KIT-negative or -weak clinical GIST samples that were obtained from progressing metastases during imatinib therapy. AXL knockdown inhibited viability in three KIT-negative GIST cell lines (GIST62, GIST54, and GIST522), but not in an AXL-negative, KIT-positive GIST control cell line (GIST430). AXL inhibition by R428, a specific AXL kinase inhibitor, reduced viability in AXL-activated GIST54. AXL knockdown in GIST62, GIST522, and GIST54 was accompanied by an increase in p21, p27, and p53 expression. By contrast, gefitinib-mediated EGFR inhibition, PF562271-mediated FAK inactivation, and shRNA-mediated knockdowns of EPHA2 and FAK had no effect on viability or colony formation of the KIT-negative GISTs. These findings highlight the potential relevance of AXL/p53 signaling as a therapeutic target in a subset of GISTs that have lost KIT oncoprotein expression.
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Affiliation(s)
- Yuqing Tu
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, China
| | - Rui Zuo
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, China
| | - Nan Ni
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, China
| | - Grant Eilers
- Department of Pathology, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA, USA
| | - Duolin Wu
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, China
| | - Yuting Pei
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, China
| | - Zuoming Nie
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, China
| | - Yeqing Wu
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, China
| | - Yuehong Wu
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, China,Yuehong Wu
| | - Wen-Bin Ou
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, China,Department of Pathology, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA, USA,Zhejiang Provincial Key Laboratory of Applied Enzymology, Yangtze Delta Region Institute of Tsinghua University, Jiaxing, Zhejiang, China,CONTACT Wen-Bin Ou
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9
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Gupta K, Eilers G, Allen A, Giraldo C, Cruz K, Sharp B, Hwang Y, Jamney P, Bushman FD, Van Duyne GD. Hierarchical structures of HIV integrase: drug-induced aggregates of HIV integrase are weak gels. Acta Crystallogr A Found Adv 2018. [DOI: 10.1107/s0108767318098677] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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10
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Yang P, Chen W, Li X, Eilers G, He Q, Liu L, Wu Y, Wu Y, Yu W, Fletcher JA, Ou WB. Downregulation of cyclin D1 sensitizes cancer cells to MDM2 antagonist Nutlin-3. Oncotarget 2018; 7:32652-63. [PMID: 27129163 PMCID: PMC5078041 DOI: 10.18632/oncotarget.8999] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2016] [Accepted: 03/31/2016] [Indexed: 12/14/2022] Open
Abstract
The MDM2-p53 pathway has a prominent oncogenic function in the pathogenesis of various cancers. Nutlin-3, a small-molecule antagonist of MDM2-p53 interaction, inhibits proliferation in cancer cells with wild-type p53. Herein, we evaluate the expression of MDM2, both the full length and a splicing variant MDM2-A, and the sensitivity of Nutlin-3 in different cancer cell lines. Included are seven cell lines with wild-type p53 (four mesothelioma, one breast cancer, one chondrosarcoma, and one leiomyosarcoma), two liposarcoma cell lines harboring MDM2 amplification and wild-type p53, and one mesothelioma cell line harboring a p53 point mutation. Nutlin-3 treatment increased expression of cyclin D1, MDM2, and p53 in cell lines with wild-type p53. Additive effects were observed in cells containing wild-type p53 through coordinated attack on MDM2-p53 binding and cyclin D1 by lentivirual shRNA knockdown or small molecule inhibition, as demonstrated by immunoblots and cell viability analyses. Further results demonstrate that MDM2 binds to cyclin D1, and that an increase in cyclin D1 expression after Nutlin-3 treatment is correlated with expression and ubiquitin E3-ligase activity of MDM2. MDM2 and p53 knockdown experiments demonstrated inhibition of cyclin D1 by MDM2 but not p53. These results indicate that combination inhibition of cyclin D1 and MDM2-p53 binding warrants clinical evaluation as a novel therapeutic strategy in cancer cells harboring wild-type p53.
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Affiliation(s)
- Peipei Yang
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, China
| | - Weicai Chen
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, China
| | - Xuhui Li
- Zhejiang Provincial Key Laboratory of Applied Enzymology, Yangtze Delta Region Institute of Tsinghua University, Jiaxing, Zhejiang, China
| | - Grant Eilers
- Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Quan He
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, China
| | - Lili Liu
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, China
| | - Yeqing Wu
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, China
| | - Yuehong Wu
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, China
| | - Wei Yu
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, China
| | - Jonathan A Fletcher
- Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Wen-Bin Ou
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, China.,Zhejiang Provincial Key Laboratory of Applied Enzymology, Yangtze Delta Region Institute of Tsinghua University, Jiaxing, Zhejiang, China.,Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
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11
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Gupta K, Eilers G, Turkki V, Hwang Y, Van Duyne GD, Bushman FD. Structural basis of drug-induced aggregation of HIV-integrase. Acta Crystallogr A Found Adv 2017. [DOI: 10.1107/s0108767317096003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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12
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Ou WB, Lu M, Eilers G, Li H, Ding J, Meng X, Wu Y, He Q, Sheng Q, Zhou HM, Fletcher JA. Co-targeting of FAK and MDM2 triggers additive anti-proliferative effects in mesothelioma via a coordinated reactivation of p53. Br J Cancer 2016; 115:1253-1263. [PMID: 27736841 PMCID: PMC5104897 DOI: 10.1038/bjc.2016.331] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 09/12/2016] [Accepted: 09/21/2016] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Improved mesothelioma patient survival will require development of novel and more effective pharmacological interventions. TP53 genomic mutations are uncommon in mesothelioma, and recent data indicate that p53 remains functional, and therefore is a potential therapeutic target in these cancers. In addition, the tumour suppressor NF2 is inactivated by genomic mechanisms in more than 80% of mesothelioma, causing upregulation of FAK activity. Because FAK is a negative regulator of p53, NF2 regulation of FAK-p53-MDM2 signalling loops were evaluated. METHODS Interactions of FAK-p53 or NF2-FAK were evaluated by phosphotyrosine-p53 immunoaffinity purification and tandem mass spectrometry, and p53, FAK, and NF2 immunoprecipitations. Activation and/or expression of FAK, p53, and NF2 were also evaluated in mesotheliomas. Effects of combination MDM2 and FAK inhibitors/shRNAs were assessed by measuring mesothelioma cell viability/growth, expression of cell cycle checkpoints, and cell cycle alterations. RESULTS We observed constitutive activation of FAK, a known negative regulator of p53, in each of 10 mesothelioma cell lines and each of nine mesothelioma surgical specimens, and FAK was associated with p53 in five of five mesothelioma cell lines. In four mesotheliomas with wild-type p53, FAK silencing by RNAi induced expression and phosphorylation of p53. However, FAK regulation of mesothelioma proliferation was not restricted to p53-dependent pathways, as demonstrated by immunoblots after FAK knockdown in JMN1B mesothelioma cells, which have mutant/inactivated p53, compared with four mesothelioma cell lines with nonmutant p53. Additive effects were obtained through a coordinated reactivation of p53, by FAK knockdown/inhibition and MDM2 inhibition, as demonstrated by immunoblots, cell viability, and cell-cycle analyses, showing increased p53 expression, apoptosis, anti-proliferative effects, and cell-cycle arrest, as compared with either intervention alone. Our results also indicate that NF2 regulates the interaction of FAK-p53 and MDM2-p53. CONCLUSIONS These findings highlight novel therapeutic opportunities in mesothelioma.
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Affiliation(s)
- Wen-Bin Ou
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, China.,Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA.,Zhejiang Provincial Key Laboratory of Applied Enzymology, Yangtze Delta Region Institute of Tsinghua University, Jiaxing, Zhejiang, China
| | - Minmin Lu
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, China
| | - Grant Eilers
- Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Hailong Li
- Zhejiang Provincial Key Laboratory of Applied Enzymology, Yangtze Delta Region Institute of Tsinghua University, Jiaxing, Zhejiang, China
| | - Jiongyan Ding
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, China
| | - Xuli Meng
- Department of Breast Cancer Surgery, Zhejiang Cancer Hospital, Hangzhou, China
| | - Yuehong Wu
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, China
| | - Quan He
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, China
| | - Qing Sheng
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, China
| | - Hai-Meng Zhou
- Zhejiang Provincial Key Laboratory of Applied Enzymology, Yangtze Delta Region Institute of Tsinghua University, Jiaxing, Zhejiang, China
| | - Jonathan A Fletcher
- Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
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13
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Ou WB, Zhu J, Eilers G, Li X, Kuang Y, Liu L, Mariño-Enríquez A, Yan Z, Li H, Meng F, Zhou H, Sheng Q, Fletcher JA. HDACi inhibits liposarcoma via targeting of the MDM2-p53 signaling axis and PTEN, irrespective of p53 mutational status. Oncotarget 2016; 6:10510-20. [PMID: 25888633 PMCID: PMC4496371 DOI: 10.18632/oncotarget.3230] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 01/28/2015] [Indexed: 02/07/2023] Open
Abstract
The MDM2-p53 pathway plays a prominent role in well-differentiated liposarcoma (LPS) pathogenesis. Here, we explore the importance of MDM2 amplification and p53 mutation in LPS independently, to determine whether HDACi are therapeutically useful in LPS. We demonstrated that simultaneous knockdown of MDM2 and p53 in p53-mutant LPS lines resulted in increased apoptosis, anti-proliferative effects, and cell cycle arrest, as compared to either intervention alone. HDACi treatment resulted in the dephosphorylation and depletion of MDM2 and p53 without affecting CDK4 and JUN expression, irrespective of p53 mutational status in MDM2-amplified LPS. In control mesothelioma cell lines, HDACi treatment resulted in down-regulation of p53 in the p53 mutant cell line JMN1B, but resulted in no changes of MDM2 and p53 in two mesothelioma lines with normal MDM2 and wild-type p53. HDACi treatment substantially decreased LPS and mesothelioma proliferation and survival, and was associated with upregulation of PTEN and p21, and inactivation of AKT. Our findings indicate that wild-type p53 depletion by HDACi is MDM2 amplification-dependent. These findings underscore the importance of targeting both MDM2 and p53 in LPS and other cancers harboring p53 mutations. Moreover, the pro-apoptotic and anti-proliferative effect of HDACi warrants further evaluation as a therapeutic strategy in MDM2-amplified LPS.
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Affiliation(s)
- Wen-Bin Ou
- College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, China.,Zhejiang Provincial Key Laboratory of Applied Enzymology, Yangtze Delta Region Institute of Tsinghua University, Jiaxing, Zhejiang, China.,Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Jiaqing Zhu
- College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, China
| | - Grant Eilers
- Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Xuhui Li
- Zhejiang Provincial Key Laboratory of Applied Enzymology, Yangtze Delta Region Institute of Tsinghua University, Jiaxing, Zhejiang, China
| | - Ye Kuang
- College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, China
| | - Li Liu
- Zhejiang Provincial Key Laboratory of Applied Enzymology, Yangtze Delta Region Institute of Tsinghua University, Jiaxing, Zhejiang, China
| | - Adrián Mariño-Enríquez
- Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Ziqin Yan
- Zhejiang Provincial Key Laboratory of Applied Enzymology, Yangtze Delta Region Institute of Tsinghua University, Jiaxing, Zhejiang, China
| | - Hailong Li
- Zhejiang Provincial Key Laboratory of Applied Enzymology, Yangtze Delta Region Institute of Tsinghua University, Jiaxing, Zhejiang, China
| | - Fanguo Meng
- Zhejiang Provincial Key Laboratory of Applied Enzymology, Yangtze Delta Region Institute of Tsinghua University, Jiaxing, Zhejiang, China
| | - Haimeng Zhou
- Zhejiang Provincial Key Laboratory of Applied Enzymology, Yangtze Delta Region Institute of Tsinghua University, Jiaxing, Zhejiang, China
| | - Qing Sheng
- College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, China
| | - Jonathan A Fletcher
- Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
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14
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Ou W, Chen W, Zhu J, Eilers G, Li X, Yang P, Li H, Meng F, Fletcher J. Abstract 2707: Downregulation of cyclin D1 sensitizes cancer cells to MDM2 antagonist Nutlin-3. Cancer Res 2015. [DOI: 10.1158/1538-7445.am2015-2707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
The MDM2-p53 pathway plays a prominent role in various cancer pathogenesis. Nutlin-3, a small-molecule antagonist of MDM2, inhibits proliferation in cancer cells with wild-type p53 by blocking the interaction of MDM2 and p53. However, different cancer cells differ greatly sensitivity of Nutlin-3 because of MDM2 amplification and/or p53 mutation status. Herein, we evaluate the sensitivity of Nutlin-3 in different cancer cell lines including four mesothelioma cell lines, one breast cancer line, and one leiomyosarcoma cell line with nonmutant p53 expression, two liposarcoma cell lines harboring MDM2 amplification and wild-type p53, and one control mesothelioma cell line JMN1B harboring p53 point mutation. Unexpectedly, Nutlin-3 treatment induced cyclin D1 expression accompanied with inhibition of MDM2-p53 interaction in nonmutant cancer cell lines. Additive effects were obtained through a coordinated attack on MDM2-p53 interaction and cyclin D1, as demonstrated by immunoblots, cell viability and cell cycle analyses, showing that lentiviral mediated cyclin D1 knockdown or drug inhibition, and block of MDM2-p53 interaction, in cancer cell lines containing wild-type p53, induced greater anti-proliferative effects, compared to either intervention alone. Further results demonstrated that upregulation of cyclin D1 after Nutlin-3 treatment to some extent was dependent on expression and ubiquitin E3-ligase activity of MDM2. These compelling anti-proliferative responses indicate that combination inhibition of cyclin D1 and MDM2-p53 interaction warrants clinical evaluation as a novel therapeutic strategy in cancer cells harboring wild-type p53.
Citation Format: Wenbin Ou, Weicai Chen, Jiaqing Zhu, Grant Eilers, Xuhui Li, Peipei Yang, Hailong Li, Fanguo Meng, Jonathan Fletcher. Downregulation of cyclin D1 sensitizes cancer cells to MDM2 antagonist Nutlin-3. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2707. doi:10.1158/1538-7445.AM2015-2707
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Affiliation(s)
- Wenbin Ou
- 1Zhejiang Sci-Tech University, Hangzhou, China
| | - Weicai Chen
- 1Zhejiang Sci-Tech University, Hangzhou, China
| | - Jiaqing Zhu
- 1Zhejiang Sci-Tech University, Hangzhou, China
| | | | - Xuhui Li
- 3Yangtze Delta Region Institute of Tsinghua University, Jiaxing, China
| | - Peipei Yang
- 1Zhejiang Sci-Tech University, Hangzhou, China
| | - Hailong Li
- 3Yangtze Delta Region Institute of Tsinghua University, Jiaxing, China
| | - Fanguo Meng
- 3Yangtze Delta Region Institute of Tsinghua University, Jiaxing, China
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15
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Marino-Enriquez A, Eilers G, Czaplinski J, Mayeda M, Tao D, Zhu M, Hornick JL, Sicinska E, Wagner AJ, Fletcher JA. Abstract 607: Genomic analyses and novel models validate CDK4 as a therapeutic target in imatinib-resistant dermatofibrosarcoma protuberans. Cancer Res 2015. [DOI: 10.1158/1538-7445.am2015-607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Dermatofibrosarcoma protuberans (DFSP) is an aggressive PDGFB-dependent cutaneous sarcoma characterized by an infiltrative growth and high rate of local recurrence. Some DFSP progress to a higher-grade fibrosarcomatous form, with rapid growth and increased risk of metastasis. Imatinib provides clinical benefit in ∼50% of patients with unresectable or metastatic DFSP. Efficacious medical therapies have not been developed for imatinib-resistant DFSP. To this end, we established the first patient-derived models of imatinib-resistant DFSP.
Cell lines and mouse xenografts were established from DFSP105, an imatinib-resistant fibrosarcomatous DFSP, and were characterized by SNP arrays and sequencing to identify targetable genomic alterations. Findings were validated in vitro and in vivo, and confirmed in a case series including 12 DFSP and 6 fibrosarcomatous DFSP. SNP analysis of DFSP105 revealed a homozygous deletion encompassing CDKN2A. The resultant p16 loss implicated CDK4/6 as a potential therapeutic target in DFSP. In further studies, we demonstrated CDKN2A homozygous deletion in 1 of 12 conventional DFSP vs. 2 of 6 fibrosarcomatous DFSP. In vitro treatment of DFSP105 with two structurally distinct selective CDK4/6 inhibitors, PD-0332991 and LEE011, led to inhibition of RB1 phosphorylation and proliferation (GI50 160 nM and 276 nM, respectively). In vivo treatment of DFSP105 with PD-0332991 (150 mg/kg) inhibited xenograft growth in mice, in comparison with imatinib-treated or untreated tumors.
In conclusion, CDKN2A deletion is a novel mechanism of DFSP genetic progression. CDK4/6 inhibition is a preclinically effective treatment against p16-negative, imatinib-resistant fibrosarcomatous DFSP, and should be evaluated as a therapeutic strategy in patients with imatinib-resistant DFSP.
Citation Format: Adrian Marino-Enriquez, Grant Eilers, Jeffrey Czaplinski, Mark Mayeda, Derrick Tao, Meijun Zhu, Jason L. Hornick, Ewa Sicinska, Andrew J. Wagner, Jonathan A. Fletcher. Genomic analyses and novel models validate CDK4 as a therapeutic target in imatinib-resistant dermatofibrosarcoma protuberans. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 607. doi:10.1158/1538-7445.AM2015-607
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Affiliation(s)
| | - Grant Eilers
- 1Brigham and Women's Hospital and Harvard Medical School, Boston, MA
| | | | - Mark Mayeda
- 1Brigham and Women's Hospital and Harvard Medical School, Boston, MA
| | - Derrick Tao
- 1Brigham and Women's Hospital and Harvard Medical School, Boston, MA
| | - Meijun Zhu
- 1Brigham and Women's Hospital and Harvard Medical School, Boston, MA
| | - Jason L. Hornick
- 1Brigham and Women's Hospital and Harvard Medical School, Boston, MA
| | - Ewa Sicinska
- 2Dana Farber Cancer Institute and Harvard Medical School, Boston, MA
| | - Andrew J. Wagner
- 2Dana Farber Cancer Institute and Harvard Medical School, Boston, MA
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16
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Eilers G, Czaplinski JT, Mayeda M, Bahri N, Tao D, Zhu M, Hornick JL, Lindeman NI, Sicinska E, Wagner AJ, Fletcher JA, Mariño-Enriquez A. CDKN2A/p16 Loss Implicates CDK4 as a Therapeutic Target in Imatinib-Resistant Dermatofibrosarcoma Protuberans. Mol Cancer Ther 2015; 14:1346-53. [PMID: 25852058 DOI: 10.1158/1535-7163.mct-14-0793] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Accepted: 03/28/2015] [Indexed: 11/16/2022]
Abstract
Dermatofibrosarcoma protuberans (DFSP) is an aggressive PDGFB-dependent cutaneous sarcoma characterized by infiltrative growth and frequent local recurrences. Some DFSP progress to a higher-grade fibrosarcomatous form, with rapid growth and increased risk of metastasis. Imatinib provides clinical benefit in approximately 50% of patients with unresectable or metastatic DFSP. However, efficacious medical therapies have not been developed for imatinib-resistant DFSP. We established a model of imatinib-resistant DFSP and evaluated CDK4/6 inhibition as a genomically credentialed targeted therapy. DFSP105, an imatinib-resistant human cell line, was established from a fibrosarcomatous DFSP (FS-DFSP), and was studied by SNP arrays and sequencing to identify targetable genomic alterations. Findings were validated in vitro and in vivo, and confirmed in a series including 12 DFSP and 6 FS-DFSP. SNP analysis of DFSP105 revealed a homozygous deletion encompassing CDKN2A and CDKN2B. The resultant p16 loss implicated CDK4/6 as a potential therapeutic target in DFSP. We further demonstrated CDKN2A homozygous deletion in 1 of 12 conventional DFSP and 2 of 6 FS-DFSP, whereas p16 expression was lost in 4 of 18 DFSP. In vitro treatment of DFSP105 with two structurally distinct selective CDK4/6 inhibitors, PD-0332991 and LEE011, led to inhibition of RB1 phosphorylation and inhibition of proliferation (GI50 160 nmol/L and 276 nmol/L, respectively). In vivo treatment of DFSP105 with PD-0332991 (150 mg/kg) inhibited xenograft growth in mice, in comparison with imatinib-treated or -untreated tumors. In conclusion, CDKN2A deletion can contribute to DFSP progression. CDK4/6 inhibition is a preclinically effective treatment against p16-negative, imatinib-resistant FS-DFSP, and should be evaluated as a therapeutic strategy in patients with unresectable or metastatic imatinib-resistant DFSP.
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Affiliation(s)
- Grant Eilers
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Jeffrey T Czaplinski
- Center for Molecular Oncologic Pathology, Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts
| | - Mark Mayeda
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Nacef Bahri
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Derrick Tao
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Meijun Zhu
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Jason L Hornick
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Neal I Lindeman
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Ewa Sicinska
- Center for Molecular Oncologic Pathology, Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts
| | - Andrew J Wagner
- Center for Sarcoma and Bone Oncology, Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts
| | - Jonathan A Fletcher
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
| | - Adrian Mariño-Enriquez
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
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17
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Wang Y, Marino-Enriquez A, Bennett R, Zhu M, Eilers G, Antonescu C, Fletche C, Raut C, Rijn MVD, Kunkel L, Demetri G, Fletcher J. Abstract 1572: Dystrophin Is a tumor suppressor in human cancers with myogenic programs. Cancer Res 2014. [DOI: 10.1158/1538-7445.am2014-1572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Many common human mesenchymal tumors, including gastrointestinal stromal tumor (GIST), rhabdomyosarcoma (RMS), and leiomyosarcoma (LMS), feature myogenic differentiation. Although presumptive initiating mutations have been identified in these cancers, the subsequent mechanisms of malignant progression are not known. Here we report that intragenic deletion of the dystrophin-encoding and muscular dystrophy-associated DMD gene is a frequent mechanism by which myogenic tumors progress to high-grade, lethal sarcomas. Genome-wide SNP screens demonstrated DMD intragenic deletions in 23 of 38 myogenic sarcomas (61%) compared to 0 of 58 non-myogenic sarcomas (p < 0.0001). Although DMD is an X-linked gene, somatic DMD deletions affected both sexes equally and DMD deletions in female patients involved the active X chromosome, resulting in functional DMD nullisomy. Dystrophin was expressed strongly in nonneoplastic and benign counterparts for GIST, RMS and LMS, and the DMD deletions in the malignant myogenic sarcomas clustered at the 5′ end of the gene, inactivating larger dystrophin isoforms, including 427kDa dystrophin, while preserving expression of an essential 71kDa isoform (Dp71) which is encoded by the DMD 3′ end. Dystrophin restoration inhibited myogenic sarcoma cell migration, invasion, anchorage independence, and invadopodia formation, and dystrophin inactivation was found in 96%, 100%, and 62% of metastatic GIST, embryonal RMS, and LMS, respectively. The genomic, clinicopathological and functional evidence validate dystrophin as a tumor suppressor and likely anti-metastatic factor, suggesting that therapies in development for muscular dystrophies may also have relevance in treatment of cancer.
Citation Format: Yuexiang Wang, Adrian Marino-Enriquez, Richard Bennett, Meijun Zhu, Grant Eilers, Cristina Antonescu, Christopher Fletche, Chandrajit Raut, Matt van de Rijn, Louis Kunkel, George Demetri, Jonathan Fletcher. Dystrophin Is a tumor suppressor in human cancers with myogenic programs. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1572. doi:10.1158/1538-7445.AM2014-1572
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18
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Garner AP, Gozgit JM, Anjum R, Vodala S, Schrock A, Zhou T, Serrano C, Eilers G, Zhu M, Ketzer J, Wardwell S, Ning Y, Song Y, Kohlmann A, Wang F, Clackson T, Heinrich MC, Fletcher JA, Bauer S, Rivera VM. Ponatinib inhibits polyclonal drug-resistant KIT oncoproteins and shows therapeutic potential in heavily pretreated gastrointestinal stromal tumor (GIST) patients. Clin Cancer Res 2014; 20:5745-5755. [PMID: 25239608 DOI: 10.1158/1078-0432.ccr-14-1397] [Citation(s) in RCA: 123] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
PURPOSE KIT is the major oncogenic driver of gastrointestinal stromal tumors (GIST). Imatinib, sunitinib, and regorafenib are approved therapies; however, efficacy is often limited by the acquisition of polyclonal secondary resistance mutations in KIT, with those located in the activation (A) loop (exons 17/18) being particularly problematic. Here, we explore the KIT-inhibitory activity of ponatinib in preclinical models and describe initial characterization of its activity in patients with GIST. EXPERIMENTAL DESIGN The cellular and in vivo activities of ponatinib, imatinib, sunitinib, and regorafenib against mutant KIT were evaluated using an accelerated mutagenesis assay and a panel of engineered and GIST-derived cell lines. The ponatinib-KIT costructure was also determined. The clinical activity of ponatinib was examined in three patients with GIST previously treated with all three FDA-approved agents. RESULTS In engineered and GIST-derived cell lines, ponatinib potently inhibited KIT exon 11 primary mutants and a range of secondary mutants, including those within the A-loop. Ponatinib also induced regression in engineered and GIST-derived tumor models containing these secondary mutations. In a mutagenesis screen, 40 nmol/L ponatinib was sufficient to suppress outgrowth of all secondary mutants except V654A, which was suppressed at 80 nmol/L. This inhibitory profile could be rationalized on the basis of structural analyses. Ponatinib (30 mg daily) displayed encouraging clinical activity in two of three patients with GIST. CONCLUSION Ponatinib possesses potent activity against most major clinically relevant KIT mutants and has demonstrated preliminary evidence of activity in patients with refractory GIST. These data strongly support further evaluation of ponatinib in patients with GIST.
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Affiliation(s)
| | | | - Rana Anjum
- ARIAD Pharmaceuticals, Inc, Cambridge, MA
| | | | | | | | - Cesar Serrano
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Grant Eilers
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Meijun Zhu
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Julia Ketzer
- Sarcoma Center, Dept. of Medical Oncology, West German Cancer Center, University of Duisburg-Essen, Essen, Germany
| | | | - Yaoyu Ning
- ARIAD Pharmaceuticals, Inc, Cambridge, MA
| | | | | | - Frank Wang
- ARIAD Pharmaceuticals, Inc, Cambridge, MA
| | | | - Michael C Heinrich
- Portland VA Medical Center and OHSU Knight Cancer Institute, Portland, Oregon
| | - Jonathan A Fletcher
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Sebastian Bauer
- Sarcoma Center, Dept. of Medical Oncology, West German Cancer Center, University of Duisburg-Essen, Essen, Germany
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Zhou S, Liu L, Li H, Eilers G, Kuang Y, Shi S, Yan Z, Li X, Corson JM, Meng F, Zhou H, Sheng Q, Fletcher JA, Ou WB. Multipoint targeting of the PI3K/mTOR pathway in mesothelioma. Br J Cancer 2014; 110:2479-88. [PMID: 24762959 PMCID: PMC4021537 DOI: 10.1038/bjc.2014.220] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Revised: 03/20/2014] [Accepted: 03/27/2014] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Mesothelioma is a notoriously chemotherapy-resistant neoplasm, as is evident in the dismal overall survival for patients with those of asbestos-associated disease. We previously demonstrated co-activation of multiple receptor tyrosine kinases (RTKs), including epidermal growth factor receptor (EGFR), MET, and AXL in mesothelioma cell lines, suggesting that these kinases could serve as novel therapeutic targets. Although clinical trials have not shown activity for EGFR inhibitors in mesothelioma, concurrent inhibition of various activated RTKs has pro-apoptotic and anti-proliferative effects in mesothelioma cell lines. Thus, we hypothesised that a coordinated network of multi-RTK activation contributes to mesothelioma tumorigenesis. METHODS Activation of PI3K/AKT/mTOR, Raf/MAPK, and co-activation of RTKs were evaluated in mesotheliomas. Effects of RTK and downstream inhibitors/shRNAs were assessed by measuring mesothelioma cell viability/growth, apoptosis, activation of signalling intermediates, expression of cell-cycle checkpoints, and cell-cycle alterations. RESULTS We demonstrate activation of the PI3K/AKT/p70S6K and RAF/MEK/MAPK pathways in mesothelioma, but not in non-neoplastic mesothelial cells. The AKT activation, but not MAPK activation, was dependent on coordinated activation of RTKs EGFR, MET, and AXL. In addition, PI3K/AKT/mTOR pathway inhibition recapitulated the anti-proliferative effects of concurrent inhibition of EGFR, MET, and AXL. Dual targeting of PI3K/mTOR by BEZ235 or a combination of RAD001 and AKT knockdown had a greater effect on mesothelioma proliferation and viability than inhibition of individual activated RTKs or downstream signalling intermediates. Inhibition of PI3K/AKT was also associated with MDM2-p53 cell-cycle regulation. CONCLUSIONS These findings show that PI3K/AKT/mTOR is a crucial survival pathway downstream of multiple activated RTKs in mesothelioma, underscoring that PI3K/mTOR is a compelling target for therapeutic intervention.
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Affiliation(s)
- S Zhou
- 1] Zhejiang Provincial Key Laboratory of Applied Enzymology, Department of Biotechnology and Biomedicine, Yangtze Delta Region Institute of Tsinghua University, Jiaxing, China [2] Department of Bioengineering, College of Biology and Chemical Engineering, Jiaxing University, Jiaxing, China
| | - L Liu
- Zhejiang Provincial Key Laboratory of Applied Enzymology, Department of Biotechnology and Biomedicine, Yangtze Delta Region Institute of Tsinghua University, Jiaxing, China
| | - H Li
- Zhejiang Provincial Key Laboratory of Applied Enzymology, Department of Biotechnology and Biomedicine, Yangtze Delta Region Institute of Tsinghua University, Jiaxing, China
| | - G Eilers
- Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Y Kuang
- Department of Biochemistry and Molecular Biology, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, China
| | - S Shi
- Zhejiang Provincial Key Laboratory of Applied Enzymology, Department of Biotechnology and Biomedicine, Yangtze Delta Region Institute of Tsinghua University, Jiaxing, China
| | - Z Yan
- Zhejiang Provincial Key Laboratory of Applied Enzymology, Department of Biotechnology and Biomedicine, Yangtze Delta Region Institute of Tsinghua University, Jiaxing, China
| | - X Li
- Zhejiang Provincial Key Laboratory of Applied Enzymology, Department of Biotechnology and Biomedicine, Yangtze Delta Region Institute of Tsinghua University, Jiaxing, China
| | - J M Corson
- Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - F Meng
- Zhejiang Provincial Key Laboratory of Applied Enzymology, Department of Biotechnology and Biomedicine, Yangtze Delta Region Institute of Tsinghua University, Jiaxing, China
| | - H Zhou
- Zhejiang Provincial Key Laboratory of Applied Enzymology, Department of Biotechnology and Biomedicine, Yangtze Delta Region Institute of Tsinghua University, Jiaxing, China
| | - Q Sheng
- Department of Biochemistry and Molecular Biology, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, China
| | - J A Fletcher
- Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - W-B Ou
- 1] Zhejiang Provincial Key Laboratory of Applied Enzymology, Department of Biotechnology and Biomedicine, Yangtze Delta Region Institute of Tsinghua University, Jiaxing, China [2] Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA [3] Department of Biochemistry and Molecular Biology, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, China
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Heinrich MC, Fletcher JA, Anjum R, Serrano-Garcia C, Vodala S, Bauer S, Town A, Zhu M, Ning Y, Eilers G, Griffith D, Patterson J, McKinley A, Wang FY, Garner AP, Rivera VM. Use of ponatinib to inhibit kinase mutations associated with drug-resistant gastrointestinal stromal tumors (GIST). J Clin Oncol 2013. [DOI: 10.1200/jco.2013.31.15_suppl.10509] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
10509 Background: Ponatinib (PO) is a multi-targeted tyrosine kinase inhibitor with potent pan-BCR-ABL activity that has recently been approved for treatment of CML and Ph+ ALL. PO also inhibits the kinase activity of KIT. Approximately 80% of gastrointestinal stromal tumors (GIST) contain primary activating KIT mutations, the majority of which cluster in exon 11. Imatinib (IM) is approved for the 1st line treatment of GIST; however, patients frequently relapse due to the acquisition of secondary resistance mutations located in either the KIT ATP-binding pocket or the activation (A) loop. Sunitinib (SU) is approved for 2nd line treatment of GIST but does not effectively inhibit A-loop mutants. Here we explored the activity of PO against major primary and secondary KIT mutants found in GIST. Methods: The drug sensitivity of KIT mutants was determined using engineered Ba/F3 cells harboring mutant forms of KIT exon 11 with or without ATP binding pocket or A-loop mutations. The abilities of PO, IM, SU, and regorafenib (RE) to inhibit viability and/or KIT kinase activity were compared using this system as well as an isogenic CHO cell system. We also profiled these same drugs using a panel of GIST cell lines, including cell lines with IM-resistant secondary KIT mutations. Results: In all in vitro systems, PO potently inhibited KIT exon 11 mutant kinases, with an IC50 of < 30 nM. PO also potently inhibited a range of secondary KIT mutants, including multiple A-loop mutant kinases. PO induced substantial tumor regression in Ba/F3 tumor models expressing a KIT exon 11 mutant with or without an A-loop mutation (D816H). Using GIST cell lines, PO inhibited the viability of those harboring primary KIT exon 11 and secondary resistance mutations more effectively than IM, SU, and RE. Importantly, in patients dosed once daily with 45 mg ponatinib, plasma concentrations achieved are predicted to lead to inhibition of all KIT mutants tested with the possible exception of V654A. Conclusions: PO potently inhibits the majority of clinically relevant KIT mutant kinases and has a broader spectrum of activity compared to IM, SU, or RE. Based on these data, a phase 2 study of PO in drug-resistant GIST is being initiated.
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Affiliation(s)
- Michael C. Heinrich
- Portland VA Medical Center and Oregon Health and Science University Knight Cancer Institute, Portland, OR
| | | | - Rana Anjum
- ARIAD Pharmaceuticals, Inc., Cambridge, MA
| | | | | | - Sebastian Bauer
- Department of Medical Oncology, West German Cancer Center, University Hospital Essen, University Duisburg-Essen, Essen, Germany
| | - Ajia Town
- Portland VA Medical Center and Oregon Health and Science University Knight Cancer Institute, Portland, OR
| | - Meijun Zhu
- Brigham and Women's Hospital/Harvard Medical School, Boston, MA
| | - Yaoyu Ning
- ARIAD Pharmaceuticals, Inc., Cambridge, MA
| | - Grant Eilers
- Brigham and Women's Hospital/Harvard Medical School, Boston, MA
| | - Diana Griffith
- Portland VA Medical Center and Oregon Health and Science University Knight Cancer Institute, Portland, OR
| | - Janice Patterson
- Portland VA Medical Center and Oregon Health and Science University Knight Cancer Institute, Portland, OR
| | - Arin McKinley
- Portland VA Medical Center and Oregon Health and Science University Knight Cancer Institute, Portland, OR
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Serrano-Garcia C, Heinrich MC, Zhu M, Raut CP, Eilers G, Ravegnini G, Demetri GD, Bauer S, Fletcher JA, George S. In vitro and in vivo activity of regorafenib (REGO) in drug-resistant gastrointestinal stromal tumors (GIST). J Clin Oncol 2013. [DOI: 10.1200/jco.2013.31.15_suppl.10510] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
10510 Background: KIT and PDGFRA mutations (mut) are the crucial transforming events in most GISTs, and tyrosine kinase inhibitors (TKIs) with activity against KIT and PDGFRA, such as imatinib (IM) (front-line therapy) and sunitinib (SU) (second-line therapy), are effective treatments in GIST patients (pts). Resistance to IM and SU is commonly associated with evolution of secondary kinase mut. REGO is a multi-targeted TKI that inhibits KIT, PDGFR, and other oncologic targets and has recently shown benefit in pts with metastatic GIST after progression on standard treatments. We evaluated the in vitro and in vivo activity of REGO compared with IM, SU, and sorafenib (SOR) (a multi-TKI structurally related to REGO). Methods: REGO, IM, SU, and SOR inhibition of viability and KIT phosphorylation was assessed in human GIST cell lines and in Ba/F3 cells transformed by KIT oncoproteins with IM-resistant ATP binding pocket or activation-loop mut. KIT/PDGFRA genotyping was performed in GISTs responding or progressing on REGO in the academic phase II clinical trial. Results: In GISTs with KIT exon 11 mutant oncoproteins, REGO potently inhibited viability, KIT phosphorylation, and downstream effector phosphorylation (AKT, MAPK, S6). IM-resistant activation loop mut were more potently inhibited by REGO than SU, whereas the gatekeeper IM-resistant mut T670I was inhibited by both REGO and SU, and the common ATP-binding pocket mutant V654A was more potently inhibited by SU than REGO. Two GIST metastases progressing in one pt after initial response to REGO contained KIT V654A mut. SOR and REGO demonstrated comparable in vitro overall activity. Representative GIST cell line viability IC50s are shown in the Table (values in bold indicate expected clinical relevance). Conclusions: In vitro studies confirm REGO is a potent inhibitor of KIT exon 11 mut in GIST and appears to have stronger activity than SU against the most common KIT activation-loop mut observed in GIST. Ongoing clinical correlative analyses from REGO-treated study patients will be presented. [Table: see text]
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Affiliation(s)
| | - Michael C. Heinrich
- Portland VA Medical Center and Oregon Health and Science University Knight Cancer Institute, Portland, OR
| | - Meijun Zhu
- Brigham and Women's Hospital/Harvard Medical School, Boston, MA
| | | | - Grant Eilers
- Brigham and Women's Hospital/Harvard Medical School, Boston, MA
| | | | | | - Sebastian Bauer
- Department of Medical Oncology, West German Cancer Center, University Hospital Essen, University Duisburg-Essen, Essen, Germany
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Ravegnini G, Mariño-Enriquez A, Slater J, Eilers G, Wang Y, Zhu M, Nucci MR, George S, Angelini S, Raut CP, Fletcher JA. MED12 mutations in leiomyosarcoma and extrauterine leiomyoma. Mod Pathol 2013; 26:743-9. [PMID: 23222489 DOI: 10.1038/modpathol.2012.203] [Citation(s) in RCA: 91] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Leiomyoma and leiomyosarcoma share morphological features and smooth muscle differentiation, and both arise most frequently within the uterine corpus of middle-aged women. However, they are considered biologically unrelated tumors due to their disparate clinical, cytogenetic, and molecular features. MED12, the mediator complex subunit 12 gene, has been recently implicated as an oncogene in as many as 70% of sporadic uterine leiomyoma. In the present study, we show MED12 hotspot exon 2 mutations in extrauterine leiomyoma (3 of 19 cases) and in leiomyosarcoma (3 of 13 uterine cases). We also show that MED12 mutations are found in both primary and metastatic leiomyosarcoma. Immunoblotting studies demonstrated MED12 protein expression in 100% of leiomyomas (13) and leiomyosarcomas (20), irrespective of MED12 exon 2 mutation status or histological grade. These findings indicate that MED12 has oncogenic roles in a broad range of smooth muscle neoplasia, including tumors arising in extrauterine locations.
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Affiliation(s)
- Gloria Ravegnini
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
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23
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Simon S, Grabellus F, Ferrera L, Galietta L, Schwindenhammer B, Mühlenberg T, Taeger G, Eilers G, Treckmann J, Breitenbuecher F, Schuler M, Taguchi T, Fletcher JA, Bauer S. DOG1 regulates growth and IGFBP5 in gastrointestinal stromal tumors. Cancer Res 2013; 73:3661-70. [PMID: 23576565 DOI: 10.1158/0008-5472.can-12-3839] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Gastrointestinal stromal tumors (GIST) are characterized by activating mutations of KIT or platelet-derived growth factor receptor α(PDGFRA), which can be therapeutically targeted by tyrosine kinase inhibitors (TKI) such as imatinib. Despite long-lasting responses, most patients eventually progress after TKI therapy. The calcium-dependent chloride channel DOG1 (ANO1/TMEM16A), which is strongly and specifically expressed in GIST, is used as a diagnostic marker to differentiate GIST from other sarcomas. Here, we report that loss of DOG1 expression occurs together with loss of KIT expression in a subset of GIST resistant to KIT inhibitors, and we illustrate the functional role of DOG1 in tumor growth, KIT expression, and imatinib response. Although DOG1 is a crucial regulator of chloride balance in GIST cells, we found that RNAi-mediated silencing or pharmacologic inhibition of DOG1 did not alter cell growth or KIT signaling in vitro. In contrast, DOG1 silencing delayed the growth of GIST xenografts in vivo. Expression profiling of explanted tumors after DOG1 blockade revealed a strong upregulation in the expression of insulin-like growth factor-binding protein 5 (IGFBP5), a potent antiangiogenic factor implicated in tumor suppression. Similar results were obtained after selection of imatinib-resistant DOG1- and KIT-negative cells derived from parental DOG1 and KIT-positive GIST cells, where a 5,000-fold increase in IGFBP5 mRNA transcripts were documented. In summary, our findings establish the oncogenic activity of DOG1 in GIST involving modulation of IGF/IGF receptor signaling in the tumor microenvironment through the antiangiogenic factor IGFBP5.
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Affiliation(s)
- Susanne Simon
- Sarcoma Center, Departments of Medical Oncology, Pathology and Neuropathology, Trauma and Orthopedic Surgery, Visceral and Transplant Surgery, West German Cancer Center, University Duisburg-Essen, University Hospital Essen, Germany
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24
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Kampfrath T, Battiato M, Maldonado P, Eilers G, Nötzold J, Mährlein S, Zbarsky V, Freimuth F, Mokrousov Y, Blügel S, Wolf M, Radu I, Oppeneer PM, Münzenberg M. Terahertz spin current pulses controlled by magnetic heterostructures. Nat Nanotechnol 2013; 8:256-60. [PMID: 23542903 DOI: 10.1038/nnano.2013.43] [Citation(s) in RCA: 130] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Accepted: 02/25/2013] [Indexed: 05/23/2023]
Abstract
In spin-based electronics, information is encoded by the spin state of electron bunches. Processing this information requires the controlled transport of spin angular momentum through a solid, preferably at frequencies reaching the so far unexplored terahertz regime. Here, we demonstrate, by experiment and theory, that the temporal shape of femtosecond spin current bursts can be manipulated by using specifically designed magnetic heterostructures. A laser pulse is used to drive spins from a ferromagnetic iron thin film into a non-magnetic cap layer that has either low (ruthenium) or high (gold) electron mobility. The resulting transient spin current is detected by means of an ultrafast, contactless amperemeter based on the inverse spin Hall effect, which converts the spin flow into a terahertz electromagnetic pulse. We find that the ruthenium cap layer yields a considerably longer spin current pulse because electrons are injected into ruthenium d states, which have a much lower mobility than gold sp states. Thus, spin current pulses and the resulting terahertz transients can be shaped by tailoring magnetic heterostructures, which opens the door to engineering high-speed spintronic devices and, potentially, broadband terahertz emitters.
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Affiliation(s)
- T Kampfrath
- Department of Physical Chemistry, Fritz Haber Institute, Faradayweg 4-6, 14195 Berlin, Germany.
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25
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Miao GX, Park YJ, Moodera JS, Seibt M, Eilers G, Münzenberg M. Disturbance of tunneling coherence by oxygen vacancy in epitaxial Fe/MgO/Fe magnetic tunnel junctions. Phys Rev Lett 2008; 100:246803. [PMID: 18643609 DOI: 10.1103/physrevlett.100.246803] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2008] [Indexed: 05/26/2023]
Abstract
Oxygen vacancies in the MgO barriers of epitaxial Fe/MgO/Fe magnetic tunnel junctions are observed to introduce symmetry-breaking scatterings and hence open up channels for noncoherent tunneling processes that follow the normal WKB approximation. The evanescent waves inside the MgO barrier thus experience two-step tunneling, the coherent followed by the noncoherent process, and lead to lower tunnel magnetoresistance, higher junction resistance, as well as increased bias and temperature dependence. The characteristic length of the symmetry scattering process is determined to be about 1.6 nm.
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Affiliation(s)
- G X Miao
- Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
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26
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Hueston WJ, Knox MA, Eilers G, Pauwels J, Lonsdorf D. The effectiveness of preterm-birth prevention educational programs for high-risk women: a meta-analysis. Obstet Gynecol 1995; 86:705-12. [PMID: 7675421 DOI: 10.1016/0029-7844(95)00202-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
OBJECTIVE To evaluate whether preterm-birth prevention educational programs are effective at reducing neonatal mortality, low birth weight (LBW), and preterm delivery. DATA SOURCES A MEDLINE literature search of English-language studies was performed, supplemented by a bibliography search of original research and review articles to locate studies assessing preterm-birth prevention programs. METHOD OF STUDY SELECTION We identified 31 studies that reported results from trials evaluating preterm-birth prevention programs. From this group, only the six randomized controlled trials evaluating preterm-birth prevention education programs satisfied criteria of homogeneity to be included in a meta-analysis. One of these six studies was a subset of another study and was excluded except when reporting outcomes that were not included in the larger report. DATA EXTRACTION AND SYNTHESIS Two independent reviewers assessed study methodology and identified the following outcomes: LBW frequency, preterm birth frequency, neonatal survival, birth weight, gestational age at delivery, and preterm labor diagnosis rates. When data were combined using meta-analytic techniques, no significant benefits were found for preterm-birth education programs in preventing neonatal death (cumulative relative risk [RR] 1.00, 95% confidence interval [CI] 0.99-1.01), LBW rates (RR 0.99, 95% CI 0.88-1.11), or preterm delivery rates (RR 1.08, 95% CI 0.92-1.27). The only statistically significant effect of preterm birth education programs appears to be an increase in the frequency at which preterm labor is diagnosed (RR 1.71, 95% CI 1.41-2.08). CONCLUSION Preterm-birth prevention educational programs appear to have little benefit in reducing preterm birth and may result in an increased rate of diagnosis of preterm labor.
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Affiliation(s)
- W J Hueston
- Department of Family Medicine, University of Wisconsin-Madison, USA
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Abstract
To determine the reliability of specimen interpretation by outpatient laboratories, 150 consecutive specimens from three family practice centers were analyzed by either two laboratory technicians (n = 99) or two family physicians (n = 51). The results showed good to excellent agreement for contamination (defined as five or more epithelial cells per high-power field) or significant pyuria (five or more white blood cells per high-power field) or hematuria (five or more red blood cells per high-power field). Agreement between laboratory technicians did not differ significantly from agreement between physicians for the interpretation of contamination or pyuria, but for hematuria, agreement was higher between technicians (P = .02). These results suggest that outpatient interpretation of microscopic urine specimens shows levels of interrater agreement similar to or better than other tests that have been evaluated.
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Affiliation(s)
- W J Hueston
- Department of Family Medicine, University of Wisconsin School of Medicine, USA
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28
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Abstract
The association between colonic cleansing and hypokalaemia was studied prospectively by monitoring the serum potassium levels in four groups of patients: groups 1 (55 patients), 2 (72 patients), and 3 (97 patients) received the same 2-day preparation of 15 g magnesium sulphate and 10 mg bisacodyl twice daily; group 4 (96 patients) received a 1-day preparation of 2.4 mg sennoside per kg of bodyweight. Groups 1 and 2 were on diuretics, but only group 2 received potassium supplementation. Serum potassium levels were measured before and after bowel preparation. Hypokalaemia was present prior to cleansing in six (11%), and after cleansing in 20 (36%) of the 55 patients in the group 1 patients on diuretics but without potassium supplements. There was, after cleansing, no significant fall in serum potassium in the group 2 patients on diuretics who received potassium supplements. No hyperkalaemia resulted from supplementation. A significant fall of the mean level of serum potassium occurred in patients in both group 3 (2-day-preparation) and group 4 (1-day-preparation). We conclude that both 1 day and 2 days of cleansing with cathartics may result in a significant fall in serum potassium, which can be prevented by oral potassium supplements. Potassium supplements (three times a day 15 ml of potassium chloride with 0.9 mmol K per ml during the preparation) in patients on diuretics may be prudent to avoid the risk of cardiac arrhythmia.
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Affiliation(s)
- G H Ritsema
- Department of Radiology, St Clara Hospital, Rotterdam, The Netherlands
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29
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Faithfull S, Fennema M, Erdmann W, Dhasmana M, Eilers G. The effects of acute ischaemia on intramyocardial oxygen tensions. Adv Exp Med Biol 1986; 200:339-48. [PMID: 3799321 DOI: 10.1007/978-1-4684-5188-7_42] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Ritsema GH, Eilers G. [Cleansing of the colon using bisacodyl and magnesium sulfate]. Ned Tijdschr Geneeskd 1984; 128:1127-30. [PMID: 6462255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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31
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Jensen TW, Eilers G. A clinical evaluation of proposed panoramic surveys using fine detail imaging. Dental magnification radiography versus rotational panoramic radiography. Dentomaxillofac Radiol 1983; 12:83-93. [PMID: 6584365 DOI: 10.1259/dmfr.1983.0015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
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32
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Eilers G. [Causes and treatment of comatous conditions in children]. Krankenpflege (Frankf) 1973; 27:425-7. [PMID: 4202319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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33
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Eilers G. [Causes and treatment of comatose conditions in children]. Dtsch Krankenpflegez 1972; 25:437-9. [PMID: 4483670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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34
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Knudsen U, Kubicki S, Eilers G, Kastein R, Mahjoub M. EEG changes after intracranial intervention. Electroencephalogr Clin Neurophysiol 1969; 26:442-3. [PMID: 4183599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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