1
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Potter DS, Du R, Bohl SR, Chow KH, Ligon KL, Bueno R, Letai A. Dynamic BH3 profiling identifies pro-apoptotic drug combinations for the treatment of malignant pleural mesothelioma. Nat Commun 2023; 14:2897. [PMID: 37210412 DOI: 10.1038/s41467-023-38552-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 05/05/2023] [Indexed: 05/22/2023] Open
Abstract
Malignant pleural mesothelioma (MPM) has relatively ineffective first/second-line therapy for advanced disease and only 18% five-year survival for early disease. Drug-induced mitochondrial priming measured by dynamic BH3 profiling identifies efficacious drugs in multiple disease settings. We use high throughput dynamic BH3 profiling (HTDBP) to identify drug combinations that prime primary MPM cells derived from patient tumors, which also prime patient derived xenograft (PDX) models. A navitoclax (BCL-xL/BCL-2/BCL-w antagonist) and AZD8055 (mTORC1/2 inhibitor) combination demonstrates efficacy in vivo in an MPM PDX model, validating HTDBP as an approach to identify efficacious drug combinations. Mechanistic investigation reveals AZD8055 treatment decreases MCL-1 protein levels, increases BIM protein levels, and increases MPM mitochondrial dependence on BCL-xL, which is exploited by navitoclax. Navitoclax treatment increases dependency on MCL-1 and increases BIM protein levels. These findings demonstrate that HTDBP can be used as a functional precision medicine tool to rationally construct combination drug regimens in MPM and other cancers.
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Affiliation(s)
- Danielle S Potter
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, 02215, USA
- Harvard Medical School, Boston, MA, 02215, USA
| | - Ruochen Du
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, 02215, USA
- Harvard Medical School, Boston, MA, 02215, USA
| | - Stephan R Bohl
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, 02215, USA
- Harvard Medical School, Boston, MA, 02215, USA
| | - Kin-Hoe Chow
- Department of Oncologic Pathology, Dana-Farber Cancer Institute, Boston, MA, 02215, USA
- Center for Patient Derived Models, Dana-Farber Cancer Institute, Boston, MA, 02215, USA
| | - Keith L Ligon
- Harvard Medical School, Boston, MA, 02215, USA
- Department of Oncologic Pathology, Dana-Farber Cancer Institute, Boston, MA, 02215, USA
- Center for Patient Derived Models, Dana-Farber Cancer Institute, Boston, MA, 02215, USA
- Department of Pathology, Brigham and Women's Hospital, Boston, MA, 02215, USA
- Cancer Biology Program, Broad Institute of MIT and Harvard, Cambridge, MA, 02142, USA
| | - Raphael Bueno
- Harvard Medical School, Boston, MA, 02215, USA
- Department of Surgery, Brigham and Women's Hospital, Boston, MA, 02115, USA
| | - Anthony Letai
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, 02215, USA.
- Harvard Medical School, Boston, MA, 02215, USA.
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2
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Szabo PM, Vajdi A, Kumar N, Tolstorukov MY, Chen BJ, Edwards R, Ligon KL, Chasalow SD, Chow KH, Shetty A, Bolisetty M, Holloway JL, Golhar R, Kidd BA, Hull PA, Houser J, Vlach L, Siemers NO, Saha S. Cancer-associated fibroblasts are the main contributors to epithelial-to-mesenchymal signatures in the tumor microenvironment. Sci Rep 2023; 13:3051. [PMID: 36810872 PMCID: PMC9944255 DOI: 10.1038/s41598-023-28480-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 01/19/2023] [Indexed: 02/24/2023] Open
Abstract
Epithelial-to-mesenchymal transition (EMT) is associated with tumor initiation, metastasis, and drug resistance. However, the mechanisms underlying these associations are largely unknown. We studied several tumor types to identify the source of EMT gene expression signals and a potential mechanism of resistance to immuno-oncology treatment. Across tumor types, EMT-related gene expression was strongly associated with expression of stroma-related genes. Based on RNA sequencing of multiple patient-derived xenograft models, EMT-related gene expression was enriched in the stroma versus parenchyma. EMT-related markers were predominantly expressed by cancer-associated fibroblasts (CAFs), cells of mesenchymal origin which produce a variety of matrix proteins and growth factors. Scores derived from a 3-gene CAF transcriptional signature (COL1A1, COL1A2, COL3A1) were sufficient to reproduce association between EMT-related markers and disease prognosis. Our results suggest that CAFs are the primary source of EMT signaling and have potential roles as biomarkers and targets for immuno-oncology therapies.
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Affiliation(s)
- Peter M. Szabo
- grid.419971.30000 0004 0374 8313Bristol Myers Squibb, Princeton, NJ USA ,grid.428458.70000 0004 1792 8104Present Address: Fate Therapeutics, San Diego, CA USA
| | - Amir Vajdi
- grid.65499.370000 0001 2106 9910Dana-Farber Cancer Institute, Boston, MA USA ,grid.417993.10000 0001 2260 0793Present Address: Merck & Co., Inc., Kenilworth, NJ USA
| | | | | | - Benjamin J. Chen
- grid.419971.30000 0004 0374 8313Bristol Myers Squibb, Cambridge, MA USA
| | - Robin Edwards
- grid.419971.30000 0004 0374 8313Bristol Myers Squibb, Princeton, NJ USA ,grid.428496.5Present Address: Daiichi Sankyo, Inc., Princeton, NJ USA
| | - Keith L. Ligon
- grid.65499.370000 0001 2106 9910Dana-Farber Cancer Institute, Boston, MA USA
| | - Scott D. Chasalow
- grid.419971.30000 0004 0374 8313Bristol Myers Squibb, Princeton, NJ USA
| | - Kin-Hoe Chow
- grid.65499.370000 0001 2106 9910Dana-Farber Cancer Institute, Boston, MA USA
| | - Aniket Shetty
- grid.65499.370000 0001 2106 9910Dana-Farber Cancer Institute, Boston, MA USA
| | - Mohan Bolisetty
- grid.419971.30000 0004 0374 8313Bristol Myers Squibb, Princeton, NJ USA
| | - James L. Holloway
- grid.419971.30000 0004 0374 8313Bristol Myers Squibb, Seattle, WA USA
| | - Ryan Golhar
- grid.419971.30000 0004 0374 8313Bristol Myers Squibb, Princeton, NJ USA
| | - Brian A. Kidd
- grid.419971.30000 0004 0374 8313Bristol Myers Squibb, Redwood City, CA USA
| | | | - Jeff Houser
- grid.419971.30000 0004 0374 8313Bristol Myers Squibb, Redwood City, CA USA
| | - Logan Vlach
- grid.419971.30000 0004 0374 8313Bristol Myers Squibb, Redwood City, CA USA ,grid.152326.10000 0001 2264 7217Present Address: Vanderbilt University, Nashville, TN USA
| | - Nathan O. Siemers
- grid.419971.30000 0004 0374 8313Bristol Myers Squibb, Princeton, NJ USA ,Present Address: Fiveprime Group, Monterey, CA USA
| | - Saurabh Saha
- grid.419971.30000 0004 0374 8313Bristol Myers Squibb, Princeton, NJ USA ,Present Address: Centessa Pharmaceuticals, Cambridge, MA USA
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3
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So J, Mabe NW, Englinger B, Chow KH, Moyer SM, Yerrum S, Trissal MC, Marques JG, Kwon JJ, Shim B, Pal S, Panditharatna E, Quinn T, Schaefer DA, Jeong D, Mayhew DL, Hwang J, Beroukhim R, Ligon KL, Stegmaier K, Filbin MG, Hahn WC. VRK1 as a synthetic lethal target in VRK2 promoter-methylated cancers of the nervous system. JCI Insight 2022; 7:e158755. [PMID: 36040810 PMCID: PMC9675470 DOI: 10.1172/jci.insight.158755] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [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: 01/25/2022] [Accepted: 08/24/2022] [Indexed: 11/17/2022] Open
Abstract
Collateral lethality occurs when loss of a gene/protein renders cancer cells dependent on its remaining paralog. Combining genome-scale CRISPR/Cas9 loss-of-function screens with RNA sequencing in over 900 cancer cell lines, we found that cancers of nervous system lineage, including adult and pediatric gliomas and neuroblastomas, required the nuclear kinase vaccinia-related kinase 1 (VRK1) for their survival in vivo. VRK1 dependency was inversely correlated with expression of its paralog VRK2. VRK2 knockout sensitized cells to VRK1 loss, and conversely, VRK2 overexpression increased cell fitness in the setting of VRK1 loss. DNA methylation of the VRK2 promoter was associated with low VRK2 expression in human neuroblastomas and adult and pediatric gliomas. Mechanistically, depletion of VRK1 reduced barrier-to-autointegration factor phosphorylation during mitosis, resulting in DNA damage and apoptosis. Together, these studies identify VRK1 as a synthetic lethal target in VRK2 promoter-methylated adult and pediatric gliomas and neuroblastomas.
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Affiliation(s)
- Jonathan So
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, USA
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Nathaniel W Mabe
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
- Department of Pediatric Oncology, Dana-Farber/Boston Children's Cancer and Blood Disorder Center and Harvard Medical School, Boston, Massachusetts, USA
| | - Bernhard Englinger
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
- Department of Pediatric Oncology, Dana-Farber/Boston Children's Cancer and Blood Disorder Center and Harvard Medical School, Boston, Massachusetts, USA
- Department of Urology, Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria
| | - Kin-Hoe Chow
- Department of Oncologic Pathology and
- Center for Patient Derived Models, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, USA
| | - Sydney M Moyer
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, USA
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Smitha Yerrum
- Department of Oncologic Pathology and
- Center for Patient Derived Models, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, USA
| | - Maria C Trissal
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
- Department of Pediatric Oncology, Dana-Farber/Boston Children's Cancer and Blood Disorder Center and Harvard Medical School, Boston, Massachusetts, USA
| | - Joana G Marques
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
- Department of Pediatric Oncology, Dana-Farber/Boston Children's Cancer and Blood Disorder Center and Harvard Medical School, Boston, Massachusetts, USA
| | - Jason J Kwon
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, USA
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Brian Shim
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, USA
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Sangita Pal
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, USA
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Eshini Panditharatna
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
- Department of Pediatric Oncology, Dana-Farber/Boston Children's Cancer and Blood Disorder Center and Harvard Medical School, Boston, Massachusetts, USA
| | - Thomas Quinn
- Department of Oncologic Pathology and
- Center for Patient Derived Models, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, USA
| | - Daniel A Schaefer
- Department of Pediatric Oncology, Dana-Farber/Boston Children's Cancer and Blood Disorder Center and Harvard Medical School, Boston, Massachusetts, USA
| | - Daeun Jeong
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
- Department of Pediatric Oncology, Dana-Farber/Boston Children's Cancer and Blood Disorder Center and Harvard Medical School, Boston, Massachusetts, USA
| | - David L Mayhew
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, USA
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
- Department of Radiation Oncology, Tufts Medical Center, Boston, Massachusetts, USA
| | - Justin Hwang
- Department of Medicine and
- Masonic Cancer Center, University of Minnesota-Twin Cities, Minneapolis, Minnesota, USA
| | - Rameen Beroukhim
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, USA
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Keith L Ligon
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
- Department of Urology, Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria
- Department of Oncologic Pathology and
| | - Kimberly Stegmaier
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
- Department of Pediatric Oncology, Dana-Farber/Boston Children's Cancer and Blood Disorder Center and Harvard Medical School, Boston, Massachusetts, USA
| | - Mariella G Filbin
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
- Department of Pediatric Oncology, Dana-Farber/Boston Children's Cancer and Blood Disorder Center and Harvard Medical School, Boston, Massachusetts, USA
| | - William C Hahn
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, USA
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
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4
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Potter DS, Du R, Chow KH, Ligon KL, Bueno R, Letai A. Abstract 3691: Dynamic BH3 profiling identifies novel combinations in malignant pleural mesothelioma with in vivo efficacy. Cancer Res 2022. [DOI: 10.1158/1538-7445.am2022-3691] [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
Currently, malignant pleural mesothelioma (MPM) is mainly treated with conventional therapies such as surgery, chemotherapy and radiation, and patients often suffer from the lack of second line therapy options. In this study, we aimed to identify efficacious drug combinations in primary MPM patient samples and novel MPM patient-derived xenograft (PDX) models to provide better therapeutic options for MPM patients. BH3 profiling is a functional assay that measures mitochondrial priming of the cell. It uses BH3 peptides derived from the BH3 domain of pro-apoptotic BH3-only Bcl-2 family members to provoke a response from viable mitochondria. When tumor cells are treated with drugs prior to BH3 profiling, early changes in their apoptosis signaling can be captured before frank apoptosis occurs. This method is termed dynamic BH3 profiling (DBP), which has been applied in multiple cancer types to identify efficacious drugs. Here, we used high throughput dynamic BH3 profiling (HTDBP) to assess hundreds of drug treatments simultaneously to identify drug combinations that increased apoptotic priming in primary MPM cells ex vivo. Next, we created novel MPM PDX models and tested these drug combinations to determine the ones that primed MPM PDX cells. The HTDBP result from MPM PDX cells recapitulated the chemical vulnerabilities of the primary MPM cells. Moreover, one of the top combination candidates that comprised of navitoclax (BCL-xL, BCL-2 and BCL-w antagonist) and AZD8055 (mTORC1/2 inhibitor) was shown to be safe and efficacious in vivo in our CPDM_011x MPM PDX model. Finally, on the molecular level, we revealed that treatment with navitoclax drove the anti-apoptotic dependence of MPM cell lines towards MCL-1, whose level was downregulated by AZD8055 treatment. In this study, we identified a novel drug combination for MPM with HTDBP that consists of navitoclax and AZD8055. In addition, our results further corroborated that DBP, as a functional assay, can be used to rationally construct novel drug combinations to improve treatment outcomes for cancer patients.
Citation Format: Danielle S. Potter, Ruochen Du, Kin-Hoe Chow, Keith L. Ligon, Raphael Bueno, Anthony Letai. Dynamic BH3 profiling identifies novel combinations in malignant pleural mesothelioma with in vivo efficacy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3691.
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Affiliation(s)
| | - Ruochen Du
- 1Dana-Farber Cancer Institute, Boston, MA
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5
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Morin E, DiGiacomo J, Novikov D, Malinowski S, Chow KH, Jones D, Alexandrescu S, Ligon K, Bandopadhayay P. LGG-48. The influence of different FGFR1 alterations on pediatric low-grade glioma tumor biology and targeted therapy response. Neuro Oncol 2022. [PMCID: PMC9165226 DOI: 10.1093/neuonc/noac079.360] [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] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Pediatric low-grade gliomas (pLGGs) have excellent survival, however, with current standard of care, most patients suffer lifelong severe sequalae. pLGGs are almost exclusively driven by single activating mutations in the MAPK pathway. Clinical trials with small molecule inhibitors in BRAF-altered pLGGs are showing promising results in early clinical trials, and similar efforts are now underway for FGFR1-altered tumors, however the underlying biology and treatment response has not been thoroughly explored in a pre-clinical setting. To explore the genetic landscape of FGFR altered gliomas we assembled a cohort of 87 patients with FGFR1-4 altered gliomas across Dana-Farber Cancer Institute, Boston Children’s Hospital and Brigham and Women’s Hospital. Within this cohort we observed that pLGGs harboring FGFR1 kinase hotspot mutations (FGFR1-N546K or -K656E) frequently harbored a second alteration associated with activation of the MAPK or mTOR pathways, most commonly in the phosphatase PTPN11, NF1 or within the FGFR1 gene itself. Additionally, we observed two previously described structural variants of FGFR1, an FGFR1 internal kinase tandem duplication (FGFR-ITD) and a fusion with TACC1 (FGFR1:TACC1). The relative impact of the different FGFR1 alterations on oncogenicity, therapeutic response and resistance has not been previously explored. To address this, we have established mouse neural stem cell models overexpressing the structural variants and hot spot mutant FGFR1 alone or in combination with a second alteration. Immunoblotting revealed that the addition of a second alteration attenuated phosphorylation of ERK, AKT and S6 and influenced cell proliferation both in normal growth conditions and in absence of growth factor. Treatment with inhibitors of FGFR (Infigratinib) and MEK (Trametinib) revealed variable sensitivity both targeted therapies, suggesting that treatment of FGFR1 driven pLGG might require tailoring to the specific FGFR1 alteration.
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Affiliation(s)
- Eric Morin
- Dana-Farber Cancer Institute , Boston, MA , USA
- The Broad Institute of MIT and Harvard , Cambridge, MA , USA
| | - Jeromy DiGiacomo
- Dana-Farber Cancer Institute , Boston, MA , USA
- The Broad Institute of MIT and Harvard , Cambridge, MA , USA
| | - Dana Novikov
- Dana-Farber Cancer Institute , Boston, MA , USA
- The Broad Institute of MIT and Harvard , Cambridge, MA , USA
| | | | | | - David Jones
- Deutsches Krebsforschungszentrum , Heidelberg , Germany
| | - Sanda Alexandrescu
- Harvard Medical School , Boston, MA , USA
- Boston Children's Hospital , Boston, MA , USA
| | - Keith Ligon
- Brigham and Women’s Hospital , Boston, MA , USA
- Dana-Farber Cancer Institute , Boston, MA , USA
| | - Pratiti Bandopadhayay
- Dana-Farber Cancer Institute , Boston, MA , USA
- The Broad Institute of MIT and Harvard , Cambridge, MA , USA
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6
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Li Y, Qiu X, Wang X, Liu H, Geck RG, Tewari A, Chow KH, Xiao T, Cejas P, Nguyen QD, Long H, Liu SX, Toker A, Brown M. Abstract P4-01-04: FGFR inhibitor mediated dismissal of SWI/SNF complexes from YAP-dependent enhancers induces therapeutic resistance in triple negative breast cancer. Cancer Res 2022. [DOI: 10.1158/1538-7445.sabcs21-p4-01-04] [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
How cancer cells adapt to evade the therapeutic effects of drugs targeting oncogenic drivers is poorly understood. Here we report an epigenetic mechanism leading to the adaptive resistance of triple-negative breast cancer (TNBC) to fibroblast growth factor receptor (FGFR) inhibitors. Prolonged FGFR inhibition suppresses the function of BRG1-dependent chromatin remodeling leading to an epigenetic state that derepresses YAP-associated enhancers. These chromatin changes induce the expression of several amino acid transporters resulting in increased intracellular levels of specific amino acids that reactivate mTORC1. Consistent with this mechanism, addition of mTORC1 or YAP inhibitors to FGFR blockade synergistically attenuated the growth of TNBC patient-derived xenografts (PDX) models. Collectively, these findings reveal a novel feedback loop involving an epigenetic state transition and metabolic reprogramming that leads to adaptive therapeutic resistance and provide new therapeutic strategies to overcome this mechanism of resistance.
Citation Format: Yihao Li, Xintao Qiu, Xiaoqing Wang, Hui Liu, Renee Geck Geck, Alok Tewari, Kin-Hoe Chow, Tengfei Xiao, Paloma Cejas, Quang-Dé Nguyen, Henry Long, Shirley X Liu, Alex Toker, Myles Brown. FGFR inhibitor mediated dismissal of SWI/SNF complexes from YAP-dependent enhancers induces therapeutic resistance in triple negative breast cancer [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P4-01-04.
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Affiliation(s)
- Yihao Li
- Dana-Farber Cancer Institute, Boston, MA
| | - Xintao Qiu
- Dana-Farber Cancer Institute, Boston, MA
| | | | - Hui Liu
- Beth Israel Deaconess Medical Center, Boston, MA
| | | | | | | | | | | | | | - Henry Long
- Dana-Farber Cancer Institute, Boston, MA
| | | | - Alex Toker
- Beth Israel Deaconess Medical Center, Boston, MA
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7
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Li Y, Qiu X, Wang X, Liu H, Geck RC, Tewari AK, Xiao T, Font-Tello A, Lim K, Jones KL, Morrow M, Vadhi R, Kao PL, Jaber A, Yerrum S, Xie Y, Chow KH, Cejas P, Nguyen QD, Long HW, Liu XS, Toker A, Brown M. FGFR-inhibitor-mediated dismissal of SWI/SNF complexes from YAP-dependent enhancers induces adaptive therapeutic resistance. Nat Cell Biol 2021; 23:1187-1198. [PMID: 34737445 DOI: 10.1038/s41556-021-00781-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 09/26/2021] [Indexed: 12/20/2022]
Abstract
How cancer cells adapt to evade the therapeutic effects of drugs targeting oncogenic drivers is poorly understood. Here we report an epigenetic mechanism leading to the adaptive resistance of triple-negative breast cancer (TNBC) to fibroblast growth factor receptor (FGFR) inhibitors. Prolonged FGFR inhibition suppresses the function of BRG1-dependent chromatin remodelling, leading to an epigenetic state that derepresses YAP-associated enhancers. These chromatin changes induce the expression of several amino acid transporters, resulting in increased intracellular levels of specific amino acids that reactivate mTORC1. Consistent with this mechanism, addition of mTORC1 or YAP inhibitors to FGFR blockade synergistically attenuated the growth of TNBC patient-derived xenograft models. Collectively, these findings reveal a feedback loop involving an epigenetic state transition and metabolic reprogramming that leads to adaptive therapeutic resistance and provides potential therapeutic strategies to overcome this mechanism of resistance.
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Affiliation(s)
- Yihao Li
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA.,Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Xintao Qiu
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA.,Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Xiaoqing Wang
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA.,Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Hui Liu
- Department of Pathology, and Cancer Center, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Renee C Geck
- Department of Pathology, and Cancer Center, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Alok K Tewari
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA.,Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Tengfei Xiao
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA.,Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Alba Font-Tello
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA.,Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Klothilda Lim
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA.,Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Kristen L Jones
- Lurie Family Imaging Center, Center for Biomedical Imaging in Oncology, Dana-Farber Cancer Institute, Boston, Boston, MA, USA
| | - Murry Morrow
- Lurie Family Imaging Center, Center for Biomedical Imaging in Oncology, Dana-Farber Cancer Institute, Boston, Boston, MA, USA
| | - Raga Vadhi
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA.,Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Pei-Lun Kao
- Department of Oncologic Pathology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA.,Center for Patient Derived Models, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Aliya Jaber
- Department of Oncologic Pathology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA.,Center for Patient Derived Models, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Smitha Yerrum
- Department of Oncologic Pathology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA.,Center for Patient Derived Models, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Yingtian Xie
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA.,Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Kin-Hoe Chow
- Department of Oncologic Pathology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA.,Center for Patient Derived Models, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Paloma Cejas
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA.,Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Quang-Dé Nguyen
- Lurie Family Imaging Center, Center for Biomedical Imaging in Oncology, Dana-Farber Cancer Institute, Boston, Boston, MA, USA
| | - Henry W Long
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA.,Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, MA, USA
| | - X Shirley Liu
- Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, MA, USA.,Department of Data Science, Dana-Farber Cancer Institute, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Alex Toker
- Department of Pathology, and Cancer Center, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.,Ludwig Center at Harvard, Harvard Medical School, Boston, MA, USA
| | - Myles Brown
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA. .,Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, MA, USA. .,Ludwig Center at Harvard, Harvard Medical School, Boston, MA, USA.
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8
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Stockslager MA, Malinowski S, Touat M, Yoon JC, Geduldig J, Mirza M, Kim AS, Wen PY, Chow KH, Ligon KL, Manalis SR. Functional drug susceptibility testing using single-cell mass predicts treatment outcome in patient-derived cancer neurosphere models. Cell Rep 2021; 37:109788. [PMID: 34610309 DOI: 10.1016/j.celrep.2021.109788] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [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: 01/13/2021] [Revised: 08/17/2021] [Accepted: 09/10/2021] [Indexed: 02/07/2023] Open
Abstract
Functional precision medicine aims to match individual cancer patients to optimal treatment through ex vivo drug susceptibility testing on patient-derived cells. However, few functional diagnostic assays have been validated against patient outcomes at scale because of limitations of such assays. Here, we describe a high-throughput assay that detects subtle changes in the mass of individual drug-treated cancer cells as a surrogate biomarker for patient treatment response. To validate this approach, we determined ex vivo response to temozolomide in a retrospective cohort of 69 glioblastoma patient-derived neurosphere models with matched patient survival and genomics. Temozolomide-induced changes in cell mass distributions predict patient overall survival similarly to O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation and may aid in predictions in gliomas with mismatch-repair variants of unknown significance, where MGMT is not predictive. Our findings suggest cell mass is a promising functional biomarker for cancers and drugs that lack genomic biomarkers.
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Affiliation(s)
- Max A Stockslager
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA; Koch Institute for Integrative Cancer Research, Cambridge, MA, USA
| | - Seth Malinowski
- Department of Oncologic Pathology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | - Mehdi Touat
- Department of Oncologic Pathology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA; Broad Institute of Harvard and MIT, Cambridge, MA, USA; Sorbonne Université, Inserm, CNRS, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, AP-HP, Hôpitaux Universitaires La Pitié Salpêtrière - Charles Foix, Service de Neurologie 2-Mazarin, Paris, France
| | - Jennifer C Yoon
- Koch Institute for Integrative Cancer Research, Cambridge, MA, USA
| | - Jack Geduldig
- Department of Oncologic Pathology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | - Mahnoor Mirza
- Koch Institute for Integrative Cancer Research, Cambridge, MA, USA
| | - Annette S Kim
- Department of Pathology, Brigham & Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Patrick Y Wen
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA USA
| | - Kin-Hoe Chow
- Center for Patient-Derived Models, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Keith L Ligon
- Department of Oncologic Pathology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA; Broad Institute of Harvard and MIT, Cambridge, MA, USA; Department of Pathology, Brigham & Women's Hospital, Harvard Medical School, Boston, MA, USA; Center for Patient-Derived Models, Dana-Farber Cancer Institute, Boston, MA, USA; Department of Pathology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
| | - Scott R Manalis
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA; Koch Institute for Integrative Cancer Research, Cambridge, MA, USA; Broad Institute of Harvard and MIT, Cambridge, MA, USA; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.
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9
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Li Y, Qiu X, Liu H, Wang X, Geck RC, Tewari A, Chow KH, Cejas P, Nguyen QD, Long H, Liu SX, Toker A, Brown M. Abstract 1400: SWI/SNF chromatin remodeling complex regulation of YAP-dependent enhancers drives therapeutic resistance in triple-negative breast cancer. Cancer Res 2021. [DOI: 10.1158/1538-7445.am2021-1400] [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
Outcomes for patients with triple negative breast cancer (TNBC) remain poor despite significant advances in the treatment of other breast cancer subtypes. We report an epigenetic mechanism leading to the adaptive resistance of TNBC to fibroblast growth factor receptor (FGFR) inhibitors. Prolonged FGFR inhibition suppresses the function of BRG1-dependent chromatin remodeling leading to an epigenetic state that derepresses YAP-associated enhancers. These chromatin changes induce the expression of several amino acid transporters resulting in increased intracellular levels of specific amino acids that reactivate mTORC1. Consistent with this mechanism, addition of mTORC1 or YAP inhibitors to FGFR blockade synergistically attenuated the growth of TNBC patient-derived xenografts (PDX) models. Treatment-induced YAP/TEAD accessible chromatin was observed in a subpopulation of PDX cells by single cell analysis of accessible chromatin. Thus, combinatorial therapies based on the YAP and mTORC1 dependent feedback loop have the potential to improve the efficacy of FGFR inhibitors in TNBC.
Citation Format: Yihao Li, Xintao Qiu, Hui Liu, Xiaoqing Wang, Renee C. Geck, Alok Tewari, Kin-Hoe Chow, Paloma Cejas, Quang-Dé Nguyen, Henry Long, Shirley X. Liu, Alex Toker, Myles Brown. SWI/SNF chromatin remodeling complex regulation of YAP-dependent enhancers drives therapeutic resistance in triple-negative breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1400.
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Affiliation(s)
- Yihao Li
- 1Dana-Farber Cancer Institute, Boston, MA
| | - Xintao Qiu
- 1Dana-Farber Cancer Institute, Boston, MA
| | - Hui Liu
- 2Beth Israel Deaconess Medical Center, Boston, MA
| | | | | | | | | | | | | | - Henry Long
- 1Dana-Farber Cancer Institute, Boston, MA
| | | | - Alex Toker
- 2Beth Israel Deaconess Medical Center, Boston, MA
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10
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Lynch KN, Liu JF, Kesten N, Chow KH, Shetty A, He R, Afreen MF, Yuan L, Matulonis UA, Growdon WB, Muto MG, Horowitz NS, Feltmate CM, Worley MJ, Berkowitz RS, Crum CP, Rueda BR, Hill SJ. Enhanced Efficacy of Aurora Kinase Inhibitors in G2/M Checkpoint Deficient TP53 Mutant Uterine Carcinomas Is Linked to the Summation of LKB1-AKT-p53 Interactions. Cancers (Basel) 2021; 13:cancers13092195. [PMID: 34063609 PMCID: PMC8125555 DOI: 10.3390/cancers13092195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Revised: 04/27/2021] [Accepted: 04/30/2021] [Indexed: 11/16/2022] Open
Abstract
Simple Summary Cancers arising from the lining of the uterus, endometrial cancers, are the most common gynecologic malignancy in the United States. Once endometrial cancer escapes the uterus and grows in distant locations, there are limited therapeutic options. The most aggressive and lethal endometrial cancers carry alterations in the protein p53, which is a critical guardian of many cellular functions. The role of these p53 alterations in endometrial cancer is not well understood. The goal of this work was to use p53 altered models of endometrial cancer to understand which, if any, therapeutically targetable vulnerabilities these p53 alterations may confer in endometrial cancer. Here we show that many of these p53 altered cells have problems with cell division which can be targeted with novel single and combination therapies. These discoveries may lead to relevant new therapies for difficult to treat advanced stage endometrial cancers. Abstract Uterine carcinoma (UC) is the most common gynecologic malignancy in the United States. TP53 mutant UCs cause a disproportionate number of deaths due to limited therapies for these tumors and the lack of mechanistic understanding of their fundamental vulnerabilities. Here we sought to understand the functional and therapeutic relevance of TP53 mutations in UC. We functionally profiled targetable TP53 dependent DNA damage repair and cell cycle control pathways in a panel of TP53 mutant UC cell lines and patient-derived organoids. There were no consistent defects in DNA damage repair pathways. Rather, most models demonstrated dependence on defective G2/M cell cycle checkpoints and subsequent upregulation of Aurora kinase-LKB1-p53-AKT signaling in the setting of baseline mitotic defects. This combination makes them sensitive to Aurora kinase inhibition. Resistant lines demonstrated an intact G2/M checkpoint, and combining Aurora kinase and WEE1 inhibitors, which then push these cells through mitosis with Aurora kinase inhibitor-induced spindle defects, led to apoptosis in these cases. Overall, this work presents Aurora kinase inhibitors alone or in combination with WEE1 inhibitors as relevant mechanism driven therapies for TP53 mutant UCs. Context specific functional assessment of the G2/M checkpoint may serve as a biomarker in identifying Aurora kinase inhibitor sensitive tumors.
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Affiliation(s)
- Katherine N. Lynch
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA; (K.N.L.); (J.F.L.); (N.K.); (M.F.A.); (U.A.M.)
- Division of Molecular and Cellular Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
| | - Joyce F. Liu
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA; (K.N.L.); (J.F.L.); (N.K.); (M.F.A.); (U.A.M.)
- Department of Medicine, Brigham and Women’s Hospital, Boston, MA 02115, USA
| | - Nikolas Kesten
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA; (K.N.L.); (J.F.L.); (N.K.); (M.F.A.); (U.A.M.)
- Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, MA 02215, USA
| | - Kin-Hoe Chow
- Center for Patient Derived Models, Dana-Farber Cancer Institute, Boston, MA 02215, USA; (K.-H.C.); (A.S.)
| | - Aniket Shetty
- Center for Patient Derived Models, Dana-Farber Cancer Institute, Boston, MA 02215, USA; (K.-H.C.); (A.S.)
| | - Ruiyang He
- Department of Biochemistry, Cambridge University, Cambridge CB2 1QW, UK;
| | - Mosammat Faria Afreen
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA; (K.N.L.); (J.F.L.); (N.K.); (M.F.A.); (U.A.M.)
- Division of Molecular and Cellular Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
| | - Liping Yuan
- Department of Pathology, Brigham and Women’s Hospital, Boston, MA 02115, USA; (L.Y.); (C.P.C.)
| | - Ursula A. Matulonis
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA; (K.N.L.); (J.F.L.); (N.K.); (M.F.A.); (U.A.M.)
- Department of Medicine, Brigham and Women’s Hospital, Boston, MA 02115, USA
| | - Whitfield B. Growdon
- Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, Massachusetts General Hospital, Boston, MA 02114, USA; (W.B.G.); (B.R.R.)
- Vincent Center for Reproductive Biology, Department of Obstetrics and Gynecology, Massachusetts General Hospital, Boston, MA 02114, USA
- Obstetrics, Gynecology and Reproductive Biology, Harvard Medical School, Boston, MA 02115, USA; (M.G.M.); (N.S.H.); (C.M.F.); (M.J.W.J.); (R.S.B.)
| | - Michael G. Muto
- Obstetrics, Gynecology and Reproductive Biology, Harvard Medical School, Boston, MA 02115, USA; (M.G.M.); (N.S.H.); (C.M.F.); (M.J.W.J.); (R.S.B.)
- Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, Brigham and Women’s Hospital, Boston, MA 02115, USA
| | - Neil S. Horowitz
- Obstetrics, Gynecology and Reproductive Biology, Harvard Medical School, Boston, MA 02115, USA; (M.G.M.); (N.S.H.); (C.M.F.); (M.J.W.J.); (R.S.B.)
- Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, Brigham and Women’s Hospital, Boston, MA 02115, USA
| | - Colleen M. Feltmate
- Obstetrics, Gynecology and Reproductive Biology, Harvard Medical School, Boston, MA 02115, USA; (M.G.M.); (N.S.H.); (C.M.F.); (M.J.W.J.); (R.S.B.)
- Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, Brigham and Women’s Hospital, Boston, MA 02115, USA
| | - Michael J. Worley
- Obstetrics, Gynecology and Reproductive Biology, Harvard Medical School, Boston, MA 02115, USA; (M.G.M.); (N.S.H.); (C.M.F.); (M.J.W.J.); (R.S.B.)
- Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, Brigham and Women’s Hospital, Boston, MA 02115, USA
| | - Ross S. Berkowitz
- Obstetrics, Gynecology and Reproductive Biology, Harvard Medical School, Boston, MA 02115, USA; (M.G.M.); (N.S.H.); (C.M.F.); (M.J.W.J.); (R.S.B.)
- Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, Brigham and Women’s Hospital, Boston, MA 02115, USA
| | - Christopher P. Crum
- Department of Pathology, Brigham and Women’s Hospital, Boston, MA 02115, USA; (L.Y.); (C.P.C.)
- Department of Pathology, Harvard Medical School, Boston, MA 02115, USA
| | - Bo R. Rueda
- Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, Massachusetts General Hospital, Boston, MA 02114, USA; (W.B.G.); (B.R.R.)
- Vincent Center for Reproductive Biology, Department of Obstetrics and Gynecology, Massachusetts General Hospital, Boston, MA 02114, USA
- Obstetrics, Gynecology and Reproductive Biology, Harvard Medical School, Boston, MA 02115, USA; (M.G.M.); (N.S.H.); (C.M.F.); (M.J.W.J.); (R.S.B.)
| | - Sarah J. Hill
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA; (K.N.L.); (J.F.L.); (N.K.); (M.F.A.); (U.A.M.)
- Division of Molecular and Cellular Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
- Department of Pathology, Brigham and Women’s Hospital, Boston, MA 02115, USA; (L.Y.); (C.P.C.)
- Department of Pathology, Harvard Medical School, Boston, MA 02115, USA
- Corresponding Author: Sarah J. Hill, Dana-Farber Cancer Institute, Smith 834, 450 Brookline Ave., Boston, MA 02215. Tel.: 617-272-5451; Fax: 617-582-8601; E-mail:
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11
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Touat M, Li YY, Boynton AN, Spurr LF, Iorgulescu B, Bohrson CL, Cortes-Ciriano I, Geduldig JE, Pelton K, Lim-Fat MJ, Pal S, Ramkissoon SH, Dubois F, Bellamy C, Currimjee N, Qian K, Malinowski S, Shetty A, Chow KH, Verreault M, Guillerm E, Ammari S, Beuvon F, Mokhtari K, Alentorn A, Dehais C, Houillier C, Laigle-Donadey F, Psimaras D, Carpentier A, Cornu P, Capelle L, Mathon B, Barnholtz-Sloan JS, Chakravarti A, Bi WL, Frampton GM, Sanson M, Alexander BM, Cherniack A, Wen PY, Reardon DA, Marabelle A, Park PJ, Idbaih A, Beroukhim R, Bandopadhayay P, Bielle F, Ligon KL. Abstract 5705: Mechanisms and therapeutic implications of hypermutation in gliomas. Cancer Res 2020. [DOI: 10.1158/1538-7445.am2020-5705] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
High tumor mutational burden (hypermutation) is observed in some gliomas; however, its mechanisms of development and whether it predicts immunotherapy response are poorly understood. Here, we comprehensively analyze the molecular determinants of mutational burden and signatures in 10,294 gliomas including AACR Project GENIE and institutional datasets. We delineate two main pathways to hypermutation: a de novo pathway associated with constitutional defects in DNA polymerase and mismatch repair (MMR) genes, and a more common post-treatment pathway associated with acquired resistance driven by MMR defects in chemotherapy-sensitive gliomas that recur after temozolomide treatment. Experimentally, the mutational signature of post-treatment hypermutated gliomas was only recapitulated by temozolomide-induced damage in cells harboring MMR deficiency. MMR-deficient gliomas exhibited unique features including the lack of prominent T-cell infiltrates, extensive intratumoral heterogeneity, poor survival and low response rate to PD-1 blockade. Moreover, while microsatellite instability in MMR-deficient gliomas was not detected by bulk analyses, single-cell whole-genome sequencing of post-treatment hypermutated glioma cells demonstrated microsatellite mutations. This study shows that chemotherapy can drive acquisition of hypermutated populations without promoting response to PD-1 blockade and supports diagnostic use of mutational burden and signatures in cancer.
Citation Format: Mehdi Touat, Yvonne Y. Li, Adam N. Boynton, Liam F. Spurr, Bryan Iorgulescu, Craig L. Bohrson, Isidro Cortes-Ciriano, Jack E. Geduldig, Kristine Pelton, Mary J. Lim-Fat, Sangita Pal, Shakti H. Ramkissoon, Frank Dubois, Charlotte Bellamy, Naomi Currimjee, Kenin Qian, Seth Malinowski, Aniket Shetty, Kin-Hoe Chow, Maïté Verreault, Erell Guillerm, Samy Ammari, Frédéric Beuvon, Karima Mokhtari, Agusti Alentorn, Caroline Dehais, Caroline Houillier, Florence Laigle-Donadey, Dimitri Psimaras, Alexandre Carpentier, Philippe Cornu, Laurent Capelle, Bertrand Mathon, Jill S. Barnholtz-Sloan, Arnab Chakravarti, Wenya L. Bi, Garrett M. Frampton, Marc Sanson, Brian M. Alexander, Andrew Cherniack, Patrick Y. Wen, David A. Reardon, Aurelien Marabelle, Peter J. Park, Ahmed Idbaih, Rameen Beroukhim, Pratiti Bandopadhayay, Franck Bielle, Keith L. Ligon. Mechanisms and therapeutic implications of hypermutation in gliomas [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5705.
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Affiliation(s)
| | | | | | - Liam F. Spurr
- 2Broad Institute of MIT and Harvard, Cambridge, MA, MA
| | | | | | - Isidro Cortes-Ciriano
- 4European Molecular European Bioinformatics Institute, Wellcome Genome Campus, HInxton, United Kingdom
| | | | | | | | - Sangita Pal
- 5Broad Institute of MIT and Harvard, Cambridge, MA
| | | | - Frank Dubois
- 5Broad Institute of MIT and Harvard, Cambridge, MA
| | | | | | - Kenin Qian
- 1Dana-Farber Cancer Institute, Boston, MA
| | | | | | | | | | - Erell Guillerm
- 8Hôpitaux Universitaires La Pitié Salpêtrière, Paris, France
| | | | | | | | | | | | | | | | | | - Alexandre Carpentier
- 11Sorbonne Université, Hôpitaux Universitaires La Pitié Salpêtrière, Paris, France
| | - Philippe Cornu
- 11Sorbonne Université, Hôpitaux Universitaires La Pitié Salpêtrière, Paris, France
| | - Laurent Capelle
- 11Sorbonne Université, Hôpitaux Universitaires La Pitié Salpêtrière, Paris, France
| | - Bertrand Mathon
- 11Sorbonne Université, Hôpitaux Universitaires La Pitié Salpêtrière, Paris, France
| | | | - Arnab Chakravarti
- 13Arthur G. James Hospital/Ohio State Comprehensive Cancer Center, Cleveland, OH
| | - Wenya L. Bi
- 14Brigham & Women's Hospital, Harvard Medical School, Boston, MA
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12
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Zeng Y, Pelton K, Yerrum S, Kao PL, Sinai C, Tran T, Sinha R, Shetty A, Tolstorukov MY, Jaber A, Freitas DE, Pisano W, Verselis SJ, Herbert ZT, Lin NU, Zhao JJ, Weinstock DM, Chukwueke UN, Aizer AA, Chiocca EA, Bi WL, Wen PY, Lee EQ, Nayak L, Meredith DM, Santagata S, Chow KH, Ligon KL. 46. PAN-CANCER ANALYSIS OF ORTHOTOPIC PATIENT DERIVED XENOGRAFTS FROM BRAIN METASTASES. Neurooncol Adv 2020. [PMCID: PMC7401414 DOI: 10.1093/noajnl/vdaa073.034] [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] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Brain metastases (BM) are a leading cause of cancer death and prognosis remains poor despite treatment advances at other sites. Models are central to therapeutic development, but few orthotopic patient-derived xenograft (PDX) models of BM exist. To represent diversity across BM types, we established a program to create orthotopic PDX at scale from all BM patients. To date BM were received from 100 patients and PDX attempted by direct brain injection (PDX, n=89) or injection of low passage patient-derived cell lines (PDCLX, n=11). We created 65 successful BM PDX from 13 cancers: 17 lung (55% take), 15 breast (68%), 6 melanoma (75%), 5 CNS lymphoma (83%), 3 gastrointestinal (75%), 2 esophageal (40%), 2 ovarian (67%), 1 sarcoma (100%), 1 laryngeal (100%), 1 prostate (100%), 1 pancreatic (100%), 1 uterine adenosarcoma (100%), and 1 yolk sac tumor (100%). Take rate was similar for models derived from patients with prior chemotherapy-only versus immune/targeted therapy-only (63 vs 58%). Fifteen patients had live tumor and matching PBMCs archived for modeling in vitro immunotherapy responses. Mean time to moribund among different cancer types ranged from 27 days (yolk sac tumor) to 177.5 days (ovarian). BM PDX had a favorable timeline for preclinical study (90% moribund at 180 days). All PDX matched the patient driver SNVs and copy aberrations, even at >P4. No significant differences noted by immunodeficient strain (SCID versus NSG) or injection site (orthotopic versus heterotopic). Explants from BM PDX were able to generate long-term cell lines (60%) or short-term cultures with qualitative concordance of model-to-patient responses to targeted therapy (Osimertinib, EGFRi) and immunotherapy (Pembrolizumab, PD1i). Genomic and clinical data were used to create the DFCI BM PDX cBioPortal for public release and models distribution will be available through the DFCI Center for Patient Derived Models.
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Affiliation(s)
- Yu Zeng
- Department of Oncologic Pathology, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Neurosurgery, Xiangya Hospital, Central South University, Changsha, China
| | - Kristine Pelton
- Department of Oncologic Pathology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Smitha Yerrum
- Center for Patient Derived Models, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Pei-Lun Kao
- Center for Patient Derived Models, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Claire Sinai
- Center for Patient Derived Models, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Tony Tran
- Center for Patient Derived Models, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Rileen Sinha
- Bioinformatics and Data Science Group, Informatics and Analytics Department, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Aniket Shetty
- Center for Patient Derived Models, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Michael Y Tolstorukov
- Bioinformatics and Data Science Group, Informatics and Analytics Department, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Aliya Jaber
- Center for Patient Derived Models, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Dylan E Freitas
- Center for Patient Derived Models, Dana-Farber Cancer Institute, Boston, MA, USA
| | - William Pisano
- Department of Oncologic Pathology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Sigitas J Verselis
- Molecular Diagnostics Laboratory, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Zach T Herbert
- The Molecular Biology Core Facilities, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Nancy U Lin
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Boston, MA, USA
| | - Jean J Zhao
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - David M Weinstock
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Boston, MA, USA
| | - Ugonma N Chukwueke
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Boston, MA, USA
| | - Ayal A Aizer
- Department of Radiation Oncology, Dana-Farber/Brigham and Women’s Cancer Center, Harvard Medical School, Boston, MA, USA
| | - E Antonio Chiocca
- Department of Neurosurgery, Brigham and Women’s Hospital, Boston, MA, USA
| | - Wenya Linda Bi
- Department of Neurosurgery, Brigham and Women’s Hospital, Boston, MA, USA
| | - Patrick Y Wen
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Boston, MA, USA
| | - Eudocia Q Lee
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Boston, MA, USA
| | - Lakshmi Nayak
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Boston, MA, USA
| | - David M Meredith
- Department of Pathology, Brigham and Women’s Hospital, Boston, MA, USA
| | - Sandro Santagata
- Department of Pathology, Brigham and Women’s Hospital, Boston, MA, USA
| | - Kin-Hoe Chow
- Department of Oncologic Pathology, Dana-Farber Cancer Institute, Boston, MA, USA
- Center for Patient Derived Models, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Keith L Ligon
- Department of Oncologic Pathology, Dana-Farber Cancer Institute, Boston, MA, USA
- Center for Patient Derived Models, Dana-Farber Cancer Institute, Boston, MA, USA
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Zhou W, Chow KH, Fleming E, Oh J. Correction: Selective colonization ability of human fecal microbes in different mouse gut environments. ISME J 2020; 14:1912-1913. [PMID: 32286547 PMCID: PMC7414016 DOI: 10.1038/s41396-020-0649-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
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Affiliation(s)
- Wei Zhou
- The Jackson Laboratory for Genomic Medicine, Farmington, CT, USA
| | | | | | - Julia Oh
- The Jackson Laboratory for Genomic Medicine, Farmington, CT, USA.
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Touat M, Li YY, Boynton AN, Spurr LF, Iorgulescu JB, Bohrson CL, Cortes-Ciriano I, Birzu C, Geduldig JE, Pelton K, Lim-Fat MJ, Pal S, Ferrer-Luna R, Ramkissoon SH, Dubois F, Bellamy C, Currimjee N, Bonardi J, Qian K, Ho P, Malinowski S, Taquet L, Jones RE, Shetty A, Chow KH, Sharaf R, Pavlick D, Albacker LA, Younan N, Baldini C, Verreault M, Giry M, Guillerm E, Ammari S, Beuvon F, Mokhtari K, Alentorn A, Dehais C, Houillier C, Laigle-Donadey F, Psimaras D, Lee EQ, Nayak L, McFaline-Figueroa JR, Carpentier A, Cornu P, Capelle L, Mathon B, Barnholtz-Sloan JS, Chakravarti A, Bi WL, Chiocca EA, Fehnel KP, Alexandrescu S, Chi SN, Haas-Kogan D, Batchelor TT, Frampton GM, Alexander BM, Huang RY, Ligon AH, Coulet F, Delattre JY, Hoang-Xuan K, Meredith DM, Santagata S, Duval A, Sanson M, Cherniack AD, Wen PY, Reardon DA, Marabelle A, Park PJ, Idbaih A, Beroukhim R, Bandopadhayay P, Bielle F, Ligon KL. Mechanisms and therapeutic implications of hypermutation in gliomas. Nature 2020; 580:517-523. [PMID: 32322066 PMCID: PMC8235024 DOI: 10.1038/s41586-020-2209-9] [Citation(s) in RCA: 328] [Impact Index Per Article: 82.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 03/04/2020] [Indexed: 12/19/2022]
Abstract
A high tumour mutational burden (hypermutation) is observed in some gliomas1-5; however, the mechanisms by which hypermutation develops and whether it predicts the response to immunotherapy are poorly understood. Here we comprehensively analyse the molecular determinants of mutational burden and signatures in 10,294 gliomas. We delineate two main pathways to hypermutation: a de novo pathway associated with constitutional defects in DNA polymerase and mismatch repair (MMR) genes, and a more common post-treatment pathway, associated with acquired resistance driven by MMR defects in chemotherapy-sensitive gliomas that recur after treatment with the chemotherapy drug temozolomide. Experimentally, the mutational signature of post-treatment hypermutated gliomas was recapitulated by temozolomide-induced damage in cells with MMR deficiency. MMR-deficient gliomas were characterized by a lack of prominent T cell infiltrates, extensive intratumoral heterogeneity, poor patient survival and a low rate of response to PD-1 blockade. Moreover, although bulk analyses did not detect microsatellite instability in MMR-deficient gliomas, single-cell whole-genome sequencing analysis of post-treatment hypermutated glioma cells identified microsatellite mutations. These results show that chemotherapy can drive the acquisition of hypermutated populations without promoting a response to PD-1 blockade and supports the diagnostic use of mutational burden and signatures in cancer.
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Affiliation(s)
- Mehdi Touat
- Department of Oncologic Pathology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA.
- Broad Institute of Harvard and MIT, Cambridge, MA, USA.
- Sorbonne Université, Inserm, CNRS, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, AP-HP, Hôpitaux Universitaires La Pitié Salpêtrière - Charles Foix, Service de Neurologie 2-Mazarin, Paris, France.
| | - Yvonne Y Li
- Broad Institute of Harvard and MIT, Cambridge, MA, USA
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | - Adam N Boynton
- Broad Institute of Harvard and MIT, Cambridge, MA, USA
- Dana-Farber/Boston Children's Cancer and Blood Disorders Center, Boston, MA, USA
| | - Liam F Spurr
- Broad Institute of Harvard and MIT, Cambridge, MA, USA
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | - J Bryan Iorgulescu
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
- Department of Pathology, Brigham & Women's Hospital, Boston, Harvard Medical School, MA, USA
| | - Craig L Bohrson
- Department of Biomedical Informatics, Harvard Medical School, Boston, MA, USA
- Bioinformatics and Integrative Genomics PhD Program, Harvard Medical School, Boston, MA, USA
| | - Isidro Cortes-Ciriano
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, UK
| | - Cristina Birzu
- Sorbonne Université, Inserm, CNRS, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, AP-HP, Hôpitaux Universitaires La Pitié Salpêtrière - Charles Foix, Service de Neurologie 2-Mazarin, Paris, France
| | - Jack E Geduldig
- Department of Oncologic Pathology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | - Kristine Pelton
- Department of Oncologic Pathology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | - Mary Jane Lim-Fat
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
- Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Sangita Pal
- Broad Institute of Harvard and MIT, Cambridge, MA, USA
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | - Ruben Ferrer-Luna
- Broad Institute of Harvard and MIT, Cambridge, MA, USA
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
- Foundation Medicine Inc., Cambridge, MA, USA
| | - Shakti H Ramkissoon
- Foundation Medicine Inc., Cambridge, MA, USA
- Wake Forest Comprehensive Cancer Center and Department of Pathology, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Frank Dubois
- Broad Institute of Harvard and MIT, Cambridge, MA, USA
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | - Charlotte Bellamy
- Department of Oncologic Pathology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | - Naomi Currimjee
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | - Juliana Bonardi
- Department of Oncologic Pathology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | - Kenin Qian
- Dana-Farber/Boston Children's Cancer and Blood Disorders Center, Boston, MA, USA
| | - Patricia Ho
- Dana-Farber/Boston Children's Cancer and Blood Disorders Center, Boston, MA, USA
| | - Seth Malinowski
- Department of Oncologic Pathology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | - Leon Taquet
- Department of Oncologic Pathology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | - Robert E Jones
- Department of Oncologic Pathology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | - Aniket Shetty
- Center for Patient Derived Models, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Kin-Hoe Chow
- Center for Patient Derived Models, Dana-Farber Cancer Institute, Boston, MA, USA
| | | | | | | | - Nadia Younan
- Sorbonne Université, Inserm, CNRS, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, AP-HP, Hôpitaux Universitaires La Pitié Salpêtrière - Charles Foix, Service de Neurologie 2-Mazarin, Paris, France
| | - Capucine Baldini
- Drug Development Department (DITEP), INSERM U1015, Université Paris Saclay, Gustave Roussy, Villejuif, France
| | - Maïté Verreault
- Sorbonne Université, Inserm, CNRS, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, Paris, France
| | - Marine Giry
- Sorbonne Université, Inserm, CNRS, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, Paris, France
| | - Erell Guillerm
- Unité fonctionnelle d'Oncogénétique et Angiogénétique Moléculaire, Département de génétique, Hôpitaux Universitaires La Pitié Salpêtrière - Charles Foix, Paris, France
| | - Samy Ammari
- Department of Diagnostic Radiology, Gustave Roussy, Villejuif, France
- IR4M (UMR8081), Université Paris-Sud, Centre National de la Recherche Scientifique, Orsay, France
| | - Frédéric Beuvon
- AP-HP, Université Paris Descartes, Hôpital Cochin, Service d'Anatomie et Cytologie Pathologiques, Paris, France
| | - Karima Mokhtari
- Sorbonne Université, Inserm, CNRS, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, AP-HP, Hôpitaux Universitaires La Pitié Salpêtrière - Charles Foix, Service de Neuropathologie Laboratoire Escourolle, Paris, France
| | - Agusti Alentorn
- Sorbonne Université, Inserm, CNRS, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, AP-HP, Hôpitaux Universitaires La Pitié Salpêtrière - Charles Foix, Service de Neurologie 2-Mazarin, Paris, France
| | - Caroline Dehais
- Sorbonne Université, Inserm, CNRS, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, AP-HP, Hôpitaux Universitaires La Pitié Salpêtrière - Charles Foix, Service de Neurologie 2-Mazarin, Paris, France
| | - Caroline Houillier
- Sorbonne Université, Inserm, CNRS, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, AP-HP, Hôpitaux Universitaires La Pitié Salpêtrière - Charles Foix, Service de Neurologie 2-Mazarin, Paris, France
| | - Florence Laigle-Donadey
- Sorbonne Université, Inserm, CNRS, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, AP-HP, Hôpitaux Universitaires La Pitié Salpêtrière - Charles Foix, Service de Neurologie 2-Mazarin, Paris, France
| | - Dimitri Psimaras
- Sorbonne Université, Inserm, CNRS, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, AP-HP, Hôpitaux Universitaires La Pitié Salpêtrière - Charles Foix, Service de Neurologie 2-Mazarin, Paris, France
| | - Eudocia Q Lee
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
- Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Lakshmi Nayak
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
- Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - J Ricardo McFaline-Figueroa
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
- Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Alexandre Carpentier
- Sorbonne Université, Inserm, CNRS, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, AP-HP, Hôpitaux Universitaires La Pitié Salpêtrière - Charles Foix, Service de Neurochirurgie, Paris, France
| | - Philippe Cornu
- Sorbonne Université, Inserm, CNRS, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, AP-HP, Hôpitaux Universitaires La Pitié Salpêtrière - Charles Foix, Service de Neurochirurgie, Paris, France
| | - Laurent Capelle
- Sorbonne Université, Inserm, CNRS, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, AP-HP, Hôpitaux Universitaires La Pitié Salpêtrière - Charles Foix, Service de Neurochirurgie, Paris, France
| | - Bertrand Mathon
- Sorbonne Université, Inserm, CNRS, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, AP-HP, Hôpitaux Universitaires La Pitié Salpêtrière - Charles Foix, Service de Neurochirurgie, Paris, France
| | - Jill S Barnholtz-Sloan
- Department of Population and Quantitative Health Sciences, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Arnab Chakravarti
- Department of Radiation Oncology, Arthur G. James Hospital/Ohio State Comprehensive Cancer Center, Columbus, OH, USA
| | - Wenya Linda Bi
- Department of Neurosurgery, Brigham & Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - E Antonio Chiocca
- Department of Neurosurgery, Brigham & Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Katie Pricola Fehnel
- Department of Neurosurgery, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Sanda Alexandrescu
- Department of Pathology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Susan N Chi
- Dana-Farber/Boston Children's Cancer and Blood Disorders Center, Boston, MA, USA
- Department of Pediatrics, Harvard Medical School, Boston, MA, USA
| | - Daphne Haas-Kogan
- Department of Radiation Oncology, Brigham and Women's Hospital, Dana-Farber Cancer Institute, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Tracy T Batchelor
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
- Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | | | - Brian M Alexander
- Foundation Medicine Inc., Cambridge, MA, USA
- Department of Radiation Oncology, Brigham and Women's Hospital, Dana-Farber Cancer Institute, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Raymond Y Huang
- Department of Radiology, Brigham and Women's Hospital, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | - Azra H Ligon
- Department of Pathology, Brigham & Women's Hospital, Boston, Harvard Medical School, MA, USA
| | - Florence Coulet
- Unité fonctionnelle d'Oncogénétique et Angiogénétique Moléculaire, Département de génétique, Hôpitaux Universitaires La Pitié Salpêtrière - Charles Foix, Paris, France
| | - Jean-Yves Delattre
- Sorbonne Université, Inserm, CNRS, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, AP-HP, Hôpitaux Universitaires La Pitié Salpêtrière - Charles Foix, Service de Neurologie 2-Mazarin, Paris, France
- Onconeurotek Tumor Bank, Institut du Cerveau et de la Moelle épinière, ICM, Paris, France
| | - Khê Hoang-Xuan
- Sorbonne Université, Inserm, CNRS, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, AP-HP, Hôpitaux Universitaires La Pitié Salpêtrière - Charles Foix, Service de Neurologie 2-Mazarin, Paris, France
| | - David M Meredith
- Department of Oncologic Pathology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
- Department of Pathology, Brigham & Women's Hospital, Boston, Harvard Medical School, MA, USA
| | - Sandro Santagata
- Department of Oncologic Pathology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
- Department of Pathology, Brigham & Women's Hospital, Boston, Harvard Medical School, MA, USA
- Ludwig Center at Harvard Medical School, Harvard Medical School, Boston, MA, USA
- Laboratory of Systems Pharmacology, Harvard Medical School, Boston, MA, USA
| | - Alex Duval
- Sorbonne Université, Inserm, UMR 938, Centre de Recherche Saint Antoine, Equipe Instabilité des Microsatellites et Cancer, Equipe labellisée par la Ligue Nationale contre le Cancer, Paris, France
| | - Marc Sanson
- Sorbonne Université, Inserm, CNRS, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, AP-HP, Hôpitaux Universitaires La Pitié Salpêtrière - Charles Foix, Service de Neurologie 2-Mazarin, Paris, France
- Onconeurotek Tumor Bank, Institut du Cerveau et de la Moelle épinière, ICM, Paris, France
| | - Andrew D Cherniack
- Broad Institute of Harvard and MIT, Cambridge, MA, USA
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | - Patrick Y Wen
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
- Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - David A Reardon
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | - Aurélien Marabelle
- Drug Development Department (DITEP), INSERM U1015, Université Paris Saclay, Gustave Roussy, Villejuif, France
| | - Peter J Park
- Department of Biomedical Informatics, Harvard Medical School, Boston, MA, USA
| | - Ahmed Idbaih
- Sorbonne Université, Inserm, CNRS, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, AP-HP, Hôpitaux Universitaires La Pitié Salpêtrière - Charles Foix, Service de Neurologie 2-Mazarin, Paris, France
| | - Rameen Beroukhim
- Broad Institute of Harvard and MIT, Cambridge, MA, USA.
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA.
- Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
| | - Pratiti Bandopadhayay
- Broad Institute of Harvard and MIT, Cambridge, MA, USA.
- Dana-Farber/Boston Children's Cancer and Blood Disorders Center, Boston, MA, USA.
- Department of Pediatrics, Harvard Medical School, Boston, MA, USA.
| | - Franck Bielle
- Sorbonne Université, Inserm, CNRS, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, AP-HP, Hôpitaux Universitaires La Pitié Salpêtrière - Charles Foix, Service de Neuropathologie Laboratoire Escourolle, Paris, France.
| | - Keith L Ligon
- Department of Oncologic Pathology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA.
- Broad Institute of Harvard and MIT, Cambridge, MA, USA.
- Department of Pathology, Brigham & Women's Hospital, Boston, Harvard Medical School, MA, USA.
- Center for Patient Derived Models, Dana-Farber Cancer Institute, Boston, MA, USA.
- Department of Pathology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
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15
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Abdelfattah N, Natarajan S, Chen Y, Chow KH, Chen SH, Olson J, Baskin D, Yun K. PDTM-09. Yap1 FUNCTION IN SEX-BIASED MEDULLOBLASTOMA FORMATION AND ANTI-TUMOR IMMUNITY. Neuro Oncol 2019. [DOI: 10.1093/neuonc/noz175.785] [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: 11/12/2022] Open
Abstract
Abstract
Immunotherapies offer remarkable potential to provide robust therapeutic benefit. Patients suffering from medulloblastoma (MB), the most frequent pediatric brain malignancy, can especially benefit from this approach, minimizing the devastating side effects of aggressive radiation and chemotherapies that disrupt normal brain development. However, regulators of the immune landscape remain poorly understood and no effective immunotherapies exist yet for MB. Here, we describe a sex-dependent Yap1 function in fSmoM2;GFAPcre SHH-MB (SG) mouse model. We show that Yap1 is both a cell-autonomous regulator of MB stem-cells and a non-cell-autonomous regulator of immune infiltrates in SHH-MB. Yap1 deletion in SG mice results in increased neuronal differentiation, significantly extended survival, and enhanced infiltration of peripheral blood immune cells (including cytotoxic T-cells, neutrophils, and macrophages). Additionally, this rescue phenotype is observed in a sex-biased manner: 65% of Yap1f/f;fSmoM2;GFAPcre males are rescued in contrast to 35% of females. These observations implicate Yap1 as a mediator of sex-biased brain-tumor formation, either through direct modulation of MB cells and/or through indirectly mediating the MB immune landscape. We are currently testing the role of sex-specific differences in the developing mouse brain to elucidate context-dependent function of Yap1 in MB genesis and maintenance.
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Affiliation(s)
- Nourhan Abdelfattah
- The Peak Center for brain and pituitary tumor, Dept of Neurosurgery, Houston Methodist Research Institute, Houston, TX, USA
| | | | - Yaohui Chen
- The Peak Center for brain and pituitary tumor, Dept of Neurosurgery, Houston Methodist Research Institute, Houston, TX, USA
| | | | - Shu-hsia Chen
- Center for Immunotherapy Research, Houston Methodist Research Institute, Houston, TX, USA
| | - James Olson
- Fred-Hutch, University of Washington School of Medicine, Seattle, WA, USA
| | - David Baskin
- The Peak Center for brain and pituitary tumor, Dept of Neurosurgery, Houston Methodist Research Institute, Houston, TX, USA
| | - Kyuson Yun
- The Peak Center for brain and pituitary tumor, Dept of Neurosurgery, Houston Methodist Research Institute, Houston, TX, USA
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16
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Zhang WC, Wells JM, Chow KH, Huang H, Yuan M, Saxena T, Melnick MA, Politi K, Asara JM, Costa DB, Bult CJ, Slack FJ. miR-147b-mediated TCA cycle dysfunction and pseudohypoxia initiate drug tolerance to EGFR inhibitors in lung adenocarcinoma. Nat Metab 2019; 1:460-474. [PMID: 31535082 PMCID: PMC6750230 DOI: 10.1038/s42255-019-0052-9] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 03/06/2019] [Indexed: 12/03/2022]
Abstract
Drug-tolerance is an acute defense response prior to a fully drug-resistant state and tumor relapse, however there are few therapeutic agents targeting drug-tolerance in the clinic. Here we show that miR-147b initiates a reversible tolerant-state to the EGFR inhibitor osimertinib in non-small cell lung cancer. With miRNA-seq analysis we find that miR-147b is the most upregulated microRNA in osimertinib-tolerant and EGFR mutated lung cancer cells. Whole transcriptome analysis of single-cell derived clones reveals a link between osimertinib-tolerance and pseudohypoxia responses irrespective of oxygen levels. Further metabolomics and genetic studies demonstrate that osimertinib-tolerance is driven by miR-147b repression of VHL and succinate dehydrogenase linked to the tricarboxylic acid cycle and pseudohypoxia pathways. Finally, pretreatment with a miR-147b inhibitor delays osimertinib-associated drug tolerance in patient-derived three-dimensional (3D) structures. This link between miR-147b and tricarboxylic acid cycle may provide promising targets for preventing tumor relapse.
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Affiliation(s)
- Wen Cai Zhang
- HMS Initiative for RNA Medicine, Department of Pathology, Cancer Center, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Julie M Wells
- Jackson Laboratory for Mammalian Genetics, Bar Harbor, ME, USA
| | - Kin-Hoe Chow
- Jackson Laboratory for Mammalian Genetics, Bar Harbor, ME, USA
| | - He Huang
- Department of Medicine, Division of Signal Transduction, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Min Yuan
- Department of Medicine, Division of Signal Transduction, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Tanvi Saxena
- HMS Initiative for RNA Medicine, Department of Pathology, Cancer Center, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Mary Ann Melnick
- Departments of Pathology and Internal Medicine (Section of Medical Oncology) and the Yale Cancer Center, Yale University School of Medicine, New Haven, CT, USA
| | - Katerina Politi
- Departments of Pathology and Internal Medicine (Section of Medical Oncology) and the Yale Cancer Center, Yale University School of Medicine, New Haven, CT, USA
| | - John M Asara
- Department of Medicine, Division of Signal Transduction, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Daniel B Costa
- Department of Medicine, Division of Hematology and Oncology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Carol J Bult
- Jackson Laboratory for Mammalian Genetics, Bar Harbor, ME, USA
| | - Frank J Slack
- HMS Initiative for RNA Medicine, Department of Pathology, Cancer Center, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
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17
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De Smet F, Tseng YY, Ramkissoon S, Ramkissoon L, Pelton K, Luna RF, Panovska D, Schoolcraft K, Watkinson F, Bilton S, Hung V, Chow KH, Geduldig J, Becker S, Jones R, Keskula P, Alkhairy S, Delmar M, Arraya J, Oh C, Yeagley A, Kramm A, Chiocca EA, Bi W(L, Kieran M, Alexander B, Dunn I, Beroukhim R, Boehm J, Ligon K. TMOD-14. A PATIENT-DERIVED CANCER CELL LINE ATLAS OF PRIMARY AND METASTATIC CENTRAL NERVOUS SYSTEM TUMORS. Neuro Oncol 2018. [DOI: 10.1093/neuonc/noy148.1126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
| | | | | | | | - Kristine Pelton
- Dana Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | | | | | | | | | | | | | | | | | - Sarah Becker
- Dana-Farber Cancer Institute / Boston Childrens Cancer and Blood Disorders Center, Boston, MA, USA
| | | | | | | | | | | | | | | | | | - E Antonio Chiocca
- Department of Neurosurgery, Brigham and Womens Hospital, Boston MA, Boston, MA, USA
| | - Wenya (Linda) Bi
- Department of Neurosurgery, Brigham and Women’s Hospital, Boston, MA, USA
| | - Mark Kieran
- Dana-Farber Cancer Institute / Boston Childrens Cancer and Blood Disorders Center / Boston Childrens Hospital, Boston, MA, USA
| | - Brian Alexander
- Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | - Ian Dunn
- Department of Neurosurgery, Brigham and Women’s Hospital, Boston, MA, USA
| | - Rameen Beroukhim
- Dana Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | | | - Keith Ligon
- Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
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18
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Wilson JJ, Chow KH, Labrie NJ, Branca JA, Sproule TJ, Perkins BRA, Wolf EE, Costa M, Stafford G, Rosales C, Mills KD, Roopenian DC, Hasham MG. Enhancing the efficacy of glycolytic blockade in cancer cells via RAD51 inhibition. Cancer Biol Ther 2018; 20:169-182. [PMID: 30183475 PMCID: PMC6343731 DOI: 10.1080/15384047.2018.1507666] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [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] [Indexed: 12/11/2022] Open
Abstract
Targeting the early steps of the glycolysis pathway in cancers is a well-established therapeutic strategy; however, the doses required to elicit a therapeutic effect on the cancer can be toxic to the patient. Consequently, numerous preclinical and clinical studies have combined glycolytic blockade with other therapies. However, most of these other therapies do not specifically target cancer cells, and thus adversely affect normal tissue. Here we first show that a diverse number of cancer models – spontaneous, patient-derived xenografted tumor samples, and xenografted human cancer cells – can be efficiently targeted by 2-deoxy-D-Glucose (2DG), a well-known glycolytic inhibitor. Next, we tested the cancer-cell specificity of a therapeutic compound using the MEC1 cell line, a chronic lymphocytic leukemia (CLL) cell line that expresses activation induced cytidine deaminase (AID). We show that MEC1 cells, are susceptible to 4,4ʹ-Diisothiocyano-2,2ʹ-stilbenedisulfonic acid (DIDS), a specific RAD51 inhibitor. We then combine 2DG and DIDS, each at a lower dose and demonstrate that this combination is more efficacious than fludarabine, the current standard- of- care treatment for CLL. This suggests that the therapeutic blockade of glycolysis together with the therapeutic inhibition of RAD51-dependent homologous recombination can be a potentially beneficial combination for targeting AID positive cancer cells with minimal adverse effects on normal tissue. Implications: Combination therapy targeting glycolysis and specific RAD51 function shows increased efficacy as compared to standard of care treatments in leukemias.
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Affiliation(s)
- John J Wilson
- a Research Department , The Jackson Laboratory , Bar Harbor , Maine , USA
| | - Kin-Hoe Chow
- a Research Department , The Jackson Laboratory , Bar Harbor , Maine , USA
| | - Nathan J Labrie
- a Research Department , The Jackson Laboratory , Bar Harbor , Maine , USA
| | - Jane A Branca
- a Research Department , The Jackson Laboratory , Bar Harbor , Maine , USA
| | - Thomas J Sproule
- a Research Department , The Jackson Laboratory , Bar Harbor , Maine , USA
| | - Bryant R A Perkins
- a Research Department , The Jackson Laboratory , Bar Harbor , Maine , USA
| | - Elise E Wolf
- a Research Department , The Jackson Laboratory , Bar Harbor , Maine , USA
| | - Mauro Costa
- a Research Department , The Jackson Laboratory , Bar Harbor , Maine , USA
| | - Grace Stafford
- a Research Department , The Jackson Laboratory , Bar Harbor , Maine , USA
| | - Christine Rosales
- a Research Department , The Jackson Laboratory , Bar Harbor , Maine , USA
| | | | - Derry C Roopenian
- a Research Department , The Jackson Laboratory , Bar Harbor , Maine , USA
| | - Muneer G Hasham
- a Research Department , The Jackson Laboratory , Bar Harbor , Maine , USA
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19
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Jeon J, Jung J, Chow KH. Electron beam induced tunneling magnetoresistance in spatially confined manganite bridges. Nanoscale 2017; 9:19304-19309. [PMID: 29192923 DOI: 10.1039/c7nr04232a] [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] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Certain manganites exhibit rich and technologically relevant transport properties which can often be attributed to the existence and changes of the intrinsic electronic phase competition within these materials. Here we demonstrate that a scanning electron beam can be used to artificially create domain configurations within La0.3Pr0.4Ca0.3MnO3 thin film microbridges that results in novel magneto-transport effects. In particular, the electron beam preferentially produces insulating regions within the narrow film and can be used to create a configuration consisting of ferromagnetic metallic domains separated by a potential barrier. This arrangement enables the spin-dependent tunneling of charge carriers and can produce large switching tunneling magnetoresistance effects which were initially absent. Hence, this work describes a new and potentially powerful method for engineering the electronic phase domains in manganites to generate functional transport properties that are important for spintronic devices.
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Affiliation(s)
- J Jeon
- Department of Physics, University of Alberta, Edmonton T6G 2E1, Canada.
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20
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Chow KH, Park HJ, George J, Yamamoto K, Gallup AD, Graber JH, Chen Y, Jiang W, Steindler DA, Neilson EG, Kim BYS, Yun K. S100A4 Is a Biomarker and Regulator of Glioma Stem Cells That Is Critical for Mesenchymal Transition in Glioblastoma. Cancer Res 2017; 77:5360-5373. [PMID: 28807938 DOI: 10.1158/0008-5472.can-17-1294] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 07/13/2017] [Accepted: 08/04/2017] [Indexed: 12/17/2022]
Abstract
Glioma stem cells (GSC) and epithelial-mesenchymal transition (EMT) are strongly associated with therapy resistance and tumor recurrence, but the underlying mechanisms are incompletely understood. Here, we show that S100A4 is a novel biomarker of GSCs. S100A4+ cells in gliomas are enriched with cancer cells that have tumor-initiating and sphere-forming abilities, with the majority located in perivascular niches where GSCs are found. Selective ablation of S100A4-expressing cells was sufficient to block tumor growth in vitro and in vivo We also identified S100A4 as a critical regulator of GSC self-renewal in mouse and patient-derived glioma tumorspheres. In contrast with previous reports of S100A4 as a reporter of EMT, we discovered that S100A4 is an upstream regulator of the master EMT regulators SNAIL2 and ZEB along with other mesenchymal transition regulators in glioblastoma. Overall, our results establish S100A4 as a central node in a molecular network that controls stemness and EMT in glioblastoma, suggesting S100A4 as a candidate therapeutic target. Cancer Res; 77(19); 5360-73. ©2017 AACR.
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Affiliation(s)
| | | | | | | | | | | | - Yuanxin Chen
- Department of Neurosurgery, Mayo Clinic, Jacksonville, Florida.,Department of Cancer Biology, Mayo Clinic, Jacksonville, Florida.,Department of Neuroscience, Mayo Clinic, Jacksonville, Florida
| | - Wen Jiang
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Dennis A Steindler
- Neuroscience and Aging Laboratory, School of Nutrition Science and Policy, Tufts University, Boston, Massachusetts
| | - Eric G Neilson
- Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Betty Y S Kim
- Department of Neurosurgery, Mayo Clinic, Jacksonville, Florida.,Department of Cancer Biology, Mayo Clinic, Jacksonville, Florida.,Department of Neuroscience, Mayo Clinic, Jacksonville, Florida
| | - Kyuson Yun
- The Jackson Laboratory, Bar Harbor, Maine. .,Kenneth R. Peak Brain and Pituitary Tumor Center, Department of Neurosurgery, Houston Methodist Research Institute, Weill Cornell Medical College, Houston, Texas
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21
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Chow KH, Park HJ, George J, Chen Y, Gallup A, Jiang W, Kim BY, Yun K. Abstract 4783: Regulation of GBM stemness and mesenchymal transition. Cancer Res 2017. [DOI: 10.1158/1538-7445.am2017-4783] [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
While growing evidence suggests that tumor microenvironment can modulate stemness and the mesenchymal phenotype, little is known about how these cell states are coordinately regulated. We report that S100A4 controls both stemness and mesenchymal transition in GBM cells. In a spontaneous mouse glioma model and in primary human GBM tumorspheres, S100A4 expression is enriched in tumor-initiating cells and is required for self-renewal and tumor growth in vivo. In addition, greater than 80 percent of S100A4+ cells are associated with the tumor vasculature, a known niche for glioma stem cells, and S100A4 promotes pro-angiogenic factor expression. Interestingly, acidosis induces expression of S100A4 and the EMT regulators SNAIL1/2 and acidosis-induced EMT regulator expression requires S100A4 function. Importantly, S100A4 functions as a molecular switch between the proneural and mesenchymal states in GBM as S100A4 knockdown results in down-regulation of the mesenchymal signature genes, including the “master transcriptional regulators of mesenchymal transition”, and concurrent up-regulation of proneural signature genes. Together, these results indicate that S100A4 sits in a critical node in the molecular network that controls both glioma stem cells and the mesenchymal phenotype.
Citation Format: Kin-Hoe Chow, Hee Jung Park, Joshy George, Yuanxin Chen, Andrew Gallup, Wen Jiang, Betty Y. Kim, Kyuson Yun. Regulation of GBM stemness and mesenchymal transition [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4783. doi:10.1158/1538-7445.AM2017-4783
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Affiliation(s)
| | | | | | | | | | - Wen Jiang
- 5UT MD Anderson Cancer Center, Houston, TX
| | | | - Kyuson Yun
- 6Houston Methodist Research Institute, Houston, TX
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22
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Ho PL, Cheung YY, Wang Y, Lo WU, Lai ELY, Chow KH, Cheng VCC. Characterization of carbapenem-resistant Escherichia coli and Klebsiella pneumoniae from a healthcare region in Hong Kong. Eur J Clin Microbiol Infect Dis 2016; 35:379-85. [PMID: 26740321 DOI: 10.1007/s10096-015-2550-3] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 12/07/2015] [Indexed: 12/21/2022]
Abstract
Carbapenem-resistant Enterobacteriaceae represents a major public health issue. This study investigated the clonality and resistance mechanisms of 92 carbapenem-resistant E. coli (n = 21) and K. pneumoniae (n = 71) isolates collected consecutively from clinical specimens and patients at high risk of carriage between 2010 and 2012 in a healthcare region in Hong Kong. Combined disk tests (CDTs) and the Carba NP test were used for phenotypic detection of carbapenemases. PCR assays were used to detect carbapenemase genes. All isolates were intermediate or resistant to at least one carbapenem. Nine (9.8 %) isolates were genotypic carbapenemase producers and included six K. pneumoniae (one ST1306/bla IMP-4, one ST889/bla IMP-4, two ST11/bla KPC-2, one ST258/bla KPC-2, one ST483/bla NDM-1) and three E. coli (one ST131/bla IMP-4, two ST744/ bla NDM-1) isolates. All nine isolates carrying carbapenemase genes could be detected by the CDTs and the Carba NP test. PCR identified bla CTX-M and bla AmpC alone or in combination in 77.8 % (7/9) and 96.4 % (80/83) of the carbapenemase-producers and non-producers, respectively. Porin loss was detected in 22.2 % (2/9) and 59.0 % (49/83) of the carbapenemase-producers and non-producers, respectively. Overall, the E. coli clones were diverse (14 different STs), but 36.6 % (26/71) of the K. pneumoniae isolates belonged to ST11. In conclusion, the prevalence of carbapenemases among carbapenem-nonsusceptible E. coli and K. pneumoniae remained low in Hong Kong. Porin loss combined with AmpC and/or CTX-M type ESBL was the major mechanism of carbapenem resistance in the study population.
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Affiliation(s)
- P L Ho
- Department of Microbiology, Queen Mary Hospital, University of Hong Kong, Pokfulam Road, Pokfulam, Hong Kong, SAR, People's Republic of China.
| | - Y Y Cheung
- Department of Microbiology, Queen Mary Hospital, University of Hong Kong, Pokfulam Road, Pokfulam, Hong Kong, SAR, People's Republic of China
| | - Y Wang
- Department of Microbiology, Queen Mary Hospital, University of Hong Kong, Pokfulam Road, Pokfulam, Hong Kong, SAR, People's Republic of China
| | - W U Lo
- Department of Microbiology, Queen Mary Hospital, University of Hong Kong, Pokfulam Road, Pokfulam, Hong Kong, SAR, People's Republic of China
| | - E L Y Lai
- Department of Microbiology, Queen Mary Hospital, University of Hong Kong, Pokfulam Road, Pokfulam, Hong Kong, SAR, People's Republic of China
| | - K H Chow
- Department of Microbiology, Queen Mary Hospital, University of Hong Kong, Pokfulam Road, Pokfulam, Hong Kong, SAR, People's Republic of China
| | - V C C Cheng
- Department of Microbiology, Queen Mary Hospital, University of Hong Kong, Pokfulam Road, Pokfulam, Hong Kong, SAR, People's Republic of China
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23
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Chow KH, Shin DM, Jenkins MH, Miller EE, Shih DJ, Choi S, Low BE, Philip V, Rybinski B, Bronson RT, Taylor MD, Yun K. Epigenetic states of cells of origin and tumor evolution drive tumor-initiating cell phenotype and tumor heterogeneity. Cancer Res 2014; 74:4864-74. [PMID: 25136069 DOI: 10.1158/0008-5472.can-13-3293] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [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] [Indexed: 12/14/2022]
Abstract
A central confounding factor in the development of targeted therapies is tumor cell heterogeneity, particularly in tumor-initiating cells (TIC), within clinically identical tumors. Here, we show how activation of the Sonic Hedgehog (SHH) pathway in neural stem and progenitor cells creates a foundation for tumor cell evolution to heterogeneous states that are histologically indistinguishable but molecularly distinct. In spontaneous medulloblastomas that arise in Patched (Ptch)(+/-) mice, we identified three distinct tumor subtypes. Through cell type-specific activation of the SHH pathway in vivo, we determined that different cells of origin evolved in unique ways to generate these subtypes. Moreover, TICs in each subtype had distinct molecular and cellular phenotypes. At the bulk tumor level, the three tumor subtypes could be distinguished by a 465-gene signature and by differential activation levels of the ERK and AKT pathways. Notably, TICs from different subtypes were differentially sensitive to SHH or AKT pathway inhibitors, highlighting new mechanisms of resistance to targeted therapies. In summary, our results show how evolutionary processes act on distinct cells of origin to contribute to tumoral heterogeneity, at both bulk tumor and TIC levels.
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Affiliation(s)
| | - Dong-Mi Shin
- Laboratory of Immunogenetics, NIAID/NIH, Bethesda, Maryland. Department of Food and Nutrition, Seoul National University, Seoul, Korea
| | | | | | - David J Shih
- Division of Neurosurgery, Program in Developmental and Stem Cell Biology, Hospital for Sick Children, Toronto, Canada
| | | | | | | | | | | | - Michael D Taylor
- Division of Neurosurgery, Program in Developmental and Stem Cell Biology, Hospital for Sick Children, Toronto, Canada
| | - Kyuson Yun
- The Jackson Laboratory, Bar Harbor, Maine.
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24
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Chow KH, Elgort S, Dasso M, Powers MA, Ullman KS. The SUMO proteases SENP1 and SENP2 play a critical role in nucleoporin homeostasis and nuclear pore complex function. Mol Biol Cell 2013; 25:160-8. [PMID: 24196834 PMCID: PMC3873886 DOI: 10.1091/mbc.e13-05-0256] [Citation(s) in RCA: 21] [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] [Indexed: 01/07/2023] Open
Abstract
A gap remains in the understanding of how nucleoporins are coordinately produced and assembled into macromolecular pore complexes. Here two vertebrate SUMO proteases are found to be important for proper assembly of nuclear pores and maintenance of homeostatic levels of certain nucleoporins. Nuclear pore complexes are composed of ∼30 different proteins, each present at the pore in multiple copies. Together these proteins create specialized channels that convey cargo between the cytoplasm and the nuclear interior. With the building blocks of nuclear pores identified, one challenge is to decipher how these proteins are coordinately produced and assembled into macromolecular pore structures with each cell division. Specific individual pore proteins and protein cofactors have been probed for their role in the assembly process, as well as certain kinases that add a layer of regulation via the phosphorylation status of nucleoporins. Other posttranslational modifications are candidates for coordinating events of pore assembly as well. In this study of two pore-associated small ubiquitin-like modifier (SUMO) proteases, sentrin/SUMO-specific protease 1 (SENP1) and SENP2, we observe that many nucleoporins are mislocalized and, in some cases, reduced in level when SENP1 and SENP2 are codepleted. The pore complexes present under these conditions are still capable of transport, although the kinetics of specific cargo is altered. These results reveal a new role for the pore-associated SENPs in nucleoporin homeostasis and in achieving proper configuration of the nuclear pore complex.
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Affiliation(s)
- Kin-Hoe Chow
- Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT 84112 Laboratory of Gene Regulation and Development, National Institute for Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892 Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322
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25
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Prokscha T, Chow KH, Stilp E, Suter A, Luetkens H, Morenzoni E, Nieuwenhuys GJ, Salman Z, Scheuermann R. Photo-induced persistent inversion of germanium in a 200-nm-deep surface region. Sci Rep 2013; 3:2569. [PMID: 23995307 PMCID: PMC3759057 DOI: 10.1038/srep02569] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Accepted: 08/19/2013] [Indexed: 11/17/2022] Open
Abstract
The controlled manipulation of the charge carrier concentration in nanometer thin layers is the basis of current semiconductor technology and of fundamental importance for device applications. Here we show that it is possible to induce a persistent inversion from n- to p-type in a 200-nm-thick surface layer of a germanium wafer by illumination with white and blue light. We induce the inversion with a half-life of ~12 hours at a temperature of 220 K which disappears above 280 K. The photo-induced inversion is absent for a sample with a 20-nm-thick gold capping layer providing a Schottky barrier at the interface. This indicates that charge accumulation at the surface is essential to explain the observed inversion. The contactless change of carrier concentration is potentially interesting for device applications in opto-electronics where the gate electrode and gate oxide could be replaced by the semiconductor surface.
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Affiliation(s)
- T Prokscha
- Paul Scherrer Institute, Laboratory for Muon Spin Spectroscopy, Villigen PSI, Switzerland.
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26
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Ho PL, Chan J, Lo WU, Law PY, Li Z, Lai EL, Chow KH. Dissemination of plasmid-mediated fosfomycin resistance fosA3 among multidrug-resistant Escherichia coli from livestock and other animals. J Appl Microbiol 2012; 114:695-702. [PMID: 23216653 DOI: 10.1111/jam.12099] [Citation(s) in RCA: 63] [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] [Received: 09/03/2012] [Revised: 11/29/2012] [Accepted: 12/04/2012] [Indexed: 11/27/2022]
Abstract
AIMS To investigate plasmid-mediated fosfomycin resistance related to fosA3 in Escherichia coli isolates collected from different animals in Hong Kong, China, 2008-2010. METHODS AND RESULTS In total, 2106 faecal specimens from 210 cattle, 214 pigs, 460 chickens, 398 stray cats, 368 stray dogs and 456 wild rodents were cultured. The faecal colonization rates of fosfomycin-resistant E. coli were as follows: 11.2% in pigs, 8.6% in cattle, 7.3% in chickens, 2.4% in dogs, 0.8% in cats and 1.5% in rodents. The cultures yielded 1693 isolates of which 831 were extended-spectrum β-lactamases (ESBL) producers. Fosfomycin-resistant isolates were more likely than fosfomycin-susceptible isolates to be producers of ESBL and to have resistance to chloramphenicol, ciprofloxacin, cotrimoxazole, gentamicin and tetracycline. Of the 101 fosfomycin-resistant isolates, 97 (96.0%) isolates were fosA3 positive and 94 (93.1%) were bla(CTX) (-M) positive. PCR mapping showed that the fosA3-containing regions were flanked by IS26, both upstream and downstream in 81 (83.5%) isolates, and by an upstream bla(CTX-M-14) -containing transposon-like structure (ΔISEcp1-bla(CTX-M-14) -ΔIS903 or ISEcp1-IS10 -bla(CTX-M-14) -ΔIS903) and a downstream IS26 in 14 (14.4%) isolates. For the remaining two isolates, fosA3 was flanked by a downstream IS26 but the upstream part cannot be defined. In a random subset of 18 isolates, fosA3 was carried on transferable plasmids with sizes of 50-200 kb and the following replicons: F2:A-B- (n = 3), F16:A1:B- (n = 2), F24:A-B- (n = 1), N (n = 1), B/O (n = 1) and untypeable (n = 3). SIGNIFICANCE AND IMPACT OF THE STUDY This study demonstrates the emergence of fosA3-mediated fosfomycin resistance among multidrug-resistant E. coli isolates from various animals. IS26 transposon-like structures might be the main vehicles for dissemination of fosA3.
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Affiliation(s)
- P L Ho
- Department of Microbiology, University of Hong Kong, Pokfulam, Hong Kong, China.
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27
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Salman Z, Ofer O, Radovic M, Hao H, Ben Shalom M, Chow KH, Dagan Y, Hossain MD, Levy CDP, Macfarlane WA, Morris GM, Patthey L, Pearson MR, Saadaoui H, Schmitt T, Wang D, Kiefl RF. Nature of weak magnetism in SrTiO3/LaAlO3 multilayers. Phys Rev Lett 2012; 109:257207. [PMID: 23368496 DOI: 10.1103/physrevlett.109.257207] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2012] [Revised: 09/20/2012] [Indexed: 06/01/2023]
Abstract
We report the observation of weak magnetism in superlattices of LaAlO(3)/SrTiO(3) using β-detected nuclear magnetic resonance. The spin lattice relaxation rate of ^{8}Li in superlattices with a spacer layers of 8 and 6 unit cells of LaAlO(3) exhibits a strong peak near ~35 K, whereas no such peak is observed in a superlattice with spacer layer thickness of 3 unit cells. We attribute the observed temperature dependence to slowing down of weakly coupled electronic moments at the LaAlO(3)/SrTiO(3) interface. These results show that the magnetism at the interface depends strongly on the thickness of the spacer layer, and that a minimal thickness of ~4-6 unit cells is required for the appearance of magnetism. A simple model is used to determine that the observed relaxation is due to small fluctuating moments (~0.002μ(B)) in the two samples with a larger LaAlO(3) spacer thickness.
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Affiliation(s)
- Z Salman
- Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland.
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28
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Ho PL, Chan J, Lo WU, Law PY, Chow KH. Plasmid-mediated fosfomycin resistance in Escherichia coli isolated from pig. Vet Microbiol 2012; 162:964-967. [PMID: 23078751 DOI: 10.1016/j.vetmic.2012.09.023] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2012] [Revised: 09/21/2012] [Accepted: 09/22/2012] [Indexed: 10/27/2022]
Abstract
Previous studies have reported plasmid-mediated fosA3 among Escherichia coli originating from human and companion animals. In this study, the plasmid, designated pHK23a originating from a multidrug-resistant E. coli isolate recovered from a slaughter pig in December 2008 in Hong Kong, China was sequenced. In conjugation, the plasmid readily transferred to E. coli J53 at high frequencies. It belongs to the narrow host range IncFII incompatibility group and is 73,607 bp in length. Sequence alignment showed that pHK23a has a 59.1 kb backbone which shares high homology with the prototype R100 plasmid and a 14.5 kb variable region. The variable region includes three genes mediating antimicrobial resistance (fosA3, Δbla(TEM-1), bla(CTX-M-3)), ten mobile genetic elements (four copies of IS26, insA, ΔinsB, ΔTn2, IS1, ΔISEcp1, Δintl1), the tir transfer inhibition protein, the pemI/pemK addiction system and eight ORFs of unknown functions (orf1, orf2, Δorf3, orf20, orf23, orf24, ycdA and ycdB). The three resistance genes were organized in a novel IS26-composite transposon-like structure. In conclusion, this is the first report of fosA3 containing plasmid in an isolate of pig origin. Since IncFII plasmids spread efficiently in Enterobacteriaceae, the detection of fosA3 with bla(CTX-M) is worrisome and might become a public health concern.
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Affiliation(s)
- P L Ho
- Department of Microbiology, University of Hong Kong, Pokfulam Road, Pokfulam, Hong Kong, China; Carol Yu Center for Infection, University of Hong Kong, Pokfulam Road, Pokfulam, Hong Kong, China.
| | - Jane Chan
- Department of Microbiology, University of Hong Kong, Pokfulam Road, Pokfulam, Hong Kong, China
| | - W U Lo
- Department of Microbiology, University of Hong Kong, Pokfulam Road, Pokfulam, Hong Kong, China
| | - Pierra Y Law
- Department of Microbiology, University of Hong Kong, Pokfulam Road, Pokfulam, Hong Kong, China
| | - K H Chow
- Department of Microbiology, University of Hong Kong, Pokfulam Road, Pokfulam, Hong Kong, China
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29
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Abstract
Numerous enzymes of the mammalian SUMO modification pathway, including two members of the SUMO protease family, SENP2 and SENP1, localize to the nuclear periphery. The SUMO proteases play roles both in processing SUMO during the biogenesis of this peptide moiety and also in reversing SUMO modification on specific targets to control the activities conferred by this post-translational modification. Although interaction with the C-terminal domain of the nucleoporin Nup153 is thought to contribute to SENP2 localization at the nuclear pore complex, little is known about the binding partners of SENP1 at the nuclear periphery. We have found that Nup153 binds to both SENP1 and SENP2 and does so by interacting with the unique N-terminal domain of Nup153 as well as a specific region within the C-terminal FG-rich region. We have further found that Nup153 is a substrate for sumoylation, with this modification kept in check by these two SUMO proteases. Specifically, either RNAi depletion of SENP1/SENP2 or expression of dominantly interfering mutants of these proteins results in increased sumoylation of endogenous Nup153. While SENP1 and SENP2 share many characteristics, we show here that SENP1 levels are influenced by the presence of Nup153, whereas SENP2 is not sensitive to changes in Nup153 abundance.
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Affiliation(s)
- Kin-Hoe Chow
- Department of Oncological Sciences, University of Utah, Salt Lake City, UT, USA
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30
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Abstract
The outcome for patients with the most common primary brain tumor, glioblastoma multiforme (GBM), remains poor. Several immunotherapeutic approaches are actively being pursued including antibodies and cell-based therapies. While the blood-brain barrier protects brain tumor cells from therapeutic antibodies, immune cells have the ability to traverse the blood-brain barrier and migrate into GBM tumors to exert their therapeutic function. Results of Phase I clinical studies with vaccines to induce GBM-specific T cells are encouraging and Phase II clinical trials are in progress. Nonvaccine-based cell therapy for GBM has been actively explored over the last four decades. Here we will review past clinical experience with adoptive cell therapies for GBM and summarize current strategies on how to improve these approaches.
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Affiliation(s)
- K H Chow
- Texas Children's Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA.
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31
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Abstract
Because of the association between aberrant nuclear structure and tumour grade, nuclear morphology is an indispensible criterion in the current pathological assessment of cancer. Components of the nuclear envelope environment have central roles in many aspects of cell function that affect tumour development and progression. As the roles of the nuclear envelope components, including nuclear pore complexes and nuclear lamina, are being deciphered in molecular detail there are opportunities to harness this knowledge for cancer therapeutics and biomarker development. In this Review, we summarize the progress that has been made in our understanding of the nuclear envelope and the implications of changes in this environment for cancer biology.
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Affiliation(s)
- Kin-Hoe Chow
- Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah 84112, USA
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32
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Ho PL, Lo WU, Wong RCW, Yeung MK, Chow KH, Que TL, Tong AHY, Bao JYJ, Lok S, Wong SSY. Complete sequencing of the FII plasmid pHK01, encoding CTX-M-14, and molecular analysis of its variants among Escherichia coli from Hong Kong. J Antimicrob Chemother 2011; 66:752-6. [PMID: 21393220 DOI: 10.1093/jac/dkr010] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVES We characterized plasmids encoding CTX-M-14 β-lactamase originating from Escherichia coli isolates recovered from patients with uncomplicated cystitis or individuals with faecal colonization in Hong Kong from 2002 to 2004. METHODS Plasmids carrying CTX-M-14 were studied by conjugation, replicon typing, S1 nuclease-PFGE and plasmid PCR-restriction fragment length polymorphism (RFLP). The complete sequence of pHK01, a 70 kb plasmid encoding CTX-M-14 from an E. coli strain, was determined and the results compared with reference plasmids and aligned with GenBank data. RESULTS The blaCTX-M-14 plasmids could be transferred in 23 of 44 E. coli strains tested. Among the 23 transconjugants, the replicon types of the CTX-M-14-encoding plasmid were FII (n=13), I1-Iγ (n=4), F1B (n=2), FII and I1-Iγ (n=1), K (80 kb, n=1) and undetermined (n=2). Plasmid pHK01 (FII replicon) shares a high degree of homology with R100 except mainly for a 11 kb variable region containing blaCTX-M-14 (with an upstream ISEcp1 and a downstream truncated IS903), an iron transport system, an outer membrane protein (malB, maltoporin) and a putative toxin-antitoxin plasmid stability system (yacABC). It was highly related to blaCTX-M-14 (pKF3-70) and blaCTX-M-24 (pEG356) plasmids reported from mainland China in 2006 and Vietnam in 2007, respectively. Subtyping by a plasmid PCR-RFLP scheme showed that 10 of the 13 FII plasmids originating from isolates collected by multiple laboratories exhibited either identical or highly similar profiles. CONCLUSIONS This study showed that narrow host-range FII plasmids play important roles in the dissemination of CTX-M-14. FII plasmids closely related to pHK01 have disseminated widely in the Hong Kong community.
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Affiliation(s)
- P L Ho
- Department of Microbiology, University of Hong Kong, Pokfulam Road, Pokfulam, Hong Kong, People's Republic of China.
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Abstract
We have determined locations for the donor and acceptor levels of muonium in six semiconductor materials (Si, Ge, GaAs, GaP, ZnSe, and 6H-SiC) as a test of defect-level pinning for hydrogen. Within theoretical band alignments, our results indicate a common energy for the equilibrium charge-transition level Mu(+/-) to within experimental uncertainties. However, this is nearly 0.5 eV higher than the energy at which the equivalent level for hydrogen was predicted to be pinned. Corrections for zero-point energy account for only about 10% of this difference. We also report experimental results for the (negative-U) difference between donor and acceptor levels for Mu to be compared with calculated values for H impurities in the same materials.
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Affiliation(s)
- R L Lichti
- Department of Physics, Texas Tech University, Lubbock, Texas 79409-1051, USA.
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Mansour AI, Salman Z, Chow KH, Fan I, King PJC, Hitti B, Jung J, Cottrell SP. Dynamics and reactivity of positively charged muonium in heavily doped Si:B and comparisons with hydrogen. Phys Rev Lett 2008; 100:257602. [PMID: 18643703 DOI: 10.1103/physrevlett.100.257602] [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] [Subscribe] [Scholar Register] [Received: 10/08/2007] [Indexed: 05/26/2023]
Abstract
The detailed dynamics of the positively charged muonium (Mu+) in heavily doped p-type Si:B is reported. Below 200 K, Mu+ is static and isolated, and is located in a stretched Si-Si bond. Above approximately 200 K, Mu+ diffuses incoherently. At temperatures higher than 300 K, the Mu+-B- complex is formed while above 520 K, it starts to dissociate. There is significant enhancement of the diffusion of Mu+ in Si compared to H+ and D+-this is attributed to its smaller mass.
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Affiliation(s)
- A I Mansour
- Department of Physics, University of Alberta, Edmonton, Alberta, Canada T6G 2G7.
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35
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Xu M, Hossain MD, Saadaoui H, Parolin TJ, Chow KH, Keeler TA, Kiefl RF, Morris GD, Salman Z, Song Q, Wang D, MacFarlane WA. Proximal magnetometry in thin films using betaNMR. J Magn Reson 2008; 191:47-55. [PMID: 18162424 DOI: 10.1016/j.jmr.2007.11.022] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2007] [Revised: 11/22/2007] [Accepted: 11/27/2007] [Indexed: 05/25/2023]
Abstract
Low energy ion implantation of hyperpolarized radioactive magnetic resonance probes allows the NMR study of thin film heterostructures by enabling depth-resolved measurements on a nanometer lengthscale. By stopping the probe ions in a layer adjacent to a layer of interest, it is possible to study magnetic fields proximally. Here we show that, in the simplest case of a uniformly magnetized layer, this yields an unperturbed in situ frequency reference. We also discuss demagnetization contributions to measured shifts for this case. With a simple illustrative calculation, we show how a nonuniformly magnetized layer causes a strongly depth-dependent line broadening in an adjacent layer. We then give some experimental examples of resonance line broadening in heterostructures.
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Affiliation(s)
- M Xu
- TRIUMF, 4004 Wesbrook Mall, Vancouver, Canada V6T 2A3
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36
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Chow KH, Courcelle J. RecBCD and RecJ/RecQ Initiate DNA Degradation on Distinct Substrates in UV-Irradiated Escherichia coli. Radiat Res 2007; 168:499-506. [PMID: 17903041 DOI: 10.1667/rr1033.1] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2007] [Accepted: 06/08/2007] [Indexed: 11/03/2022]
Abstract
After UV irradiation, recA mutants fail to recover replication, and a dramatic and nearly complete degradation of the genomic DNA occurs. Although the RecBCD helicase/nuclease complex is known to mediate this catastrophic DNA degradation, it is not known how or where this degradation is initiated. Previous studies have speculated that RecBCD targets and initiates degradation from the nascent DNA at replication forks arrested by DNA damage. To test this question, we examined which enzymes were responsible for the degradation of genomic DNA and the nascent DNA in UV-irradiated recA cells. We show here that, although RecBCD degrades the genomic DNA after UV irradiation, it does not target the nascent DNA at arrested replication forks. Instead, we observed that the nascent DNA at arrested replication forks in recA cultures is degraded by RecJ/RecQ, similar to what occurs in wild-type cultures. These findings indicate that the genomic DNA degradation and nascent DNA degradation in UV-irradiated recA mutants are mediated separately through RecBCD and RecJ/RecQ, respectively. In addition, they demonstrate that RecBCD initiates degradation at a site(s) other than the arrested replication fork directly.
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Affiliation(s)
- Kin-Hoe Chow
- Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah 84112, USA
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37
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Mukai K, Ikedo Y, Nozaki H, Sugiyama J, Nishiyama K, Andreica D, Amato A, Russo PL, Ansaldo EJ, Brewer JH, Chow KH, Ariyoshi K, Ohzuku T. Magnetic phase diagram of layered cobalt dioxide LixCoO2. Phys Rev Lett 2007; 99:087601. [PMID: 17930981 DOI: 10.1103/physrevlett.99.087601] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2006] [Indexed: 05/25/2023]
Abstract
The magnetism of LixCoO2 (LCO), which has a similar structure to NaxCoO2 (NCO), has been investigated by muon-spin spectroscopy and susceptibility measurements using samples with x=0.1-1 prepared by an electrochemical reaction. In the x range below 0.75, LCO was found to be Pauli paramagnetic down to 1.8 K, suggesting an intermediate- or weak-coupling regime, although disordered local moments, with volume fractions below approximately 20%, appear at low T for LCO with x > or = 0.5. The phase diagram and interactions of LCO are thus strikingly different from NCO, while the differences cannot be explained simply by structural differences between the two systems.
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Affiliation(s)
- K Mukai
- Toyota Central Research and Development Labs Inc, Nagakute, Aichi, Japan
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38
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Salman Z, Chow KH, Miller RI, Morello A, Parolin TJ, Hossain MD, Keeler TA, Levy CDP, MacFarlane WA, Morris GD, Saadaoui H, Wang D, Sessoli R, Condorelli GG, Kiefl RF. Local magnetic properties of a monolayer of Mn12 single molecule magnets. Nano Lett 2007; 7:1551-5. [PMID: 17488049 DOI: 10.1021/nl070366a] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The magnetic properties of a monolayer of Mn12 single molecule magnets grafted onto a silicon (Si) substrate have been investigated using depth-controlled beta-detected nuclear magnetic resonance. A low-energy beam of spin-polarized radioactive 8Li was used to probe the local static magnetic field distribution near the Mn12 monolayer in the Si substrate. The resonance line width varies strongly as a function of implantation depth as a result of the magnetic dipolar fields generated by the Mn12 electronic magnetic moments. The temperature dependence of the line width indicates that the magnetic properties of the Mn12 moments in this low-dimensional configuration differ from bulk Mn12.
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Affiliation(s)
- Z Salman
- Clarendon Laboratory, Department of Physics, Oxford University, Parks Road, Oxford OX1 3PU, UK.
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39
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Ho PL, Poon WWN, Loke SL, Leung MST, Chow KH, Wong RCW, Yip KS, Lai EL, Tsang KWT. Community emergence of CTX-M type extended-spectrum β-lactamases among urinary Escherichia coli from women. J Antimicrob Chemother 2007; 60:140-4. [PMID: 17496058 DOI: 10.1093/jac/dkm144] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [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: 11/14/2022] Open
Abstract
OBJECTIVES To conduct a territory-wide study of extended-spectrum beta-lactamases (ESBLs) among community isolates of urinary Escherichia coli from women in Hong Kong. METHODS Up to 50 consecutive single-patient E. coli isolates, collected from 13 laboratories in 2004, were studied. The ESBLs were characterized by PCR sequencing using specific primers. The epidemiological relationship of the isolates was studied by PFGE and phylogenetic group PCRs. RESULTS Forty-two ESBL producers were found among 600 consecutive isolates tested. The ESBL prevalence was 7.3% (15/205) for women aged 18-35 years, 5% (11/219) for women aged 36-50 years, 6.3% (4/63) for women aged 51-64 years and 10.6% (12/113) for women aged >or=65 years (P=0.3). The ESBL-producing isolates were often multidrug-resistant and CTX-M-14 was found in 37 isolates, CTX-M-15 in 3 isolates and CTX-M-3 in 2 isolates. PFGE revealed no significant clusters among the ESBL producers. Overall, CTX-M-14 producers were significantly more likely to belong to group D than non-ESBL producers [18/37 (48.6%) versus 13/57 (22.8%), P=0.009]. However, 7 of 13 (53.8%) CTX-M-14 producers from women aged 18-35 years represented phylogenetic group B2, compared with 7 of 24 (29.2%) for women of all other ages (P=0.1). CONCLUSIONS The study documented the community emergence of CTX-M as the predominant ESBL type among urinary isolates from women. The spread of CTX-M enzymes among isolates from young women is concerning and deserves close monitoring.
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Affiliation(s)
- P L Ho
- Division of Infectious Diseases, Department of Microbiology and Centre of Infection, The University of Hong Kong, Pokfulam Road, Hong Kong Special Administrative Region, China.
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40
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Salman Z, Wang D, Chow KH, Hossain MD, Kreitzman SR, Keeler TA, Levy CDP, MacFarlane WA, Miller RI, Morris GD, Parolin TJ, Saadaoui H, Smadella M, Kiefl RF. Magnetic-field effects on the size of vortices below the surface of NbSe2 detected using low energy beta-NMR. Phys Rev Lett 2007; 98:167001. [PMID: 17501451 DOI: 10.1103/physrevlett.98.167001] [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: 06/14/2006] [Indexed: 05/15/2023]
Abstract
A low energy radioactive beam of polarized 8Li has been used to observe the vortex lattice near the surface of superconducting NbSe2. The inhomogeneous magnetic-field distribution associated with the vortex lattice was measured using depth-resolved beta-detected NMR. Below Tc, one observes the characteristic line shape for a triangular vortex lattice which depends on the magnetic penetration depth and vortex core radius. The size of the vortex core varies strongly with the magnetic field. In particular, in a low field of 10.8 mT, the core radius is much larger than the coherence length. The possible origin of these giant vortices is discussed.
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Affiliation(s)
- Z Salman
- TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, Canada
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41
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Parolin TJ, Salman Z, Chakhalian J, Song Q, Chow KH, Hossain MD, Keeler TA, Kiefl RF, Kreitzman SR, Levy CDP, Miller RI, Morris GD, Pearson MR, Saadaoui H, Wang D, MacFarlane WA. beta-NMR of isolated lithium in nearly ferromagnetic palladium. Phys Rev Lett 2007; 98:047601. [PMID: 17358812 DOI: 10.1103/physrevlett.98.047601] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2006] [Indexed: 05/14/2023]
Abstract
The temperature dependence of the frequency shift and spin-lattice relaxation rate of isolated, nonmagnetic (8)Li impurities implanted in a nearly ferromagnetic host (Pd) are measured by means of beta-detected nuclear magnetic resonance (beta-NMR). The shift is negative, very large, and increases monotonically with decreasing T in proportion to the bulk susceptibility of Pd for T > T* approximately 100 K. Below T*, an additional shift occurs which we attribute to the response of Pd to the defect. The relaxation rate is much slower than expected for the large shift and is linear with T below T*, showing no sign of additional relaxation mechanisms associated with the defect.
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Affiliation(s)
- T J Parolin
- Department of Chemistry, University of British Columbia, Vancouver, BC, V6T 1Z1, Canada
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Courcelle CT, Chow KH, Casey A, Courcelle J. Nascent DNA processing by RecJ favors lesion repair over translesion synthesis at arrested replication forks in Escherichia coli. Proc Natl Acad Sci U S A 2006; 103:9154-9. [PMID: 16754873 PMCID: PMC1482582 DOI: 10.1073/pnas.0600785103] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.8] [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: 01/31/2006] [Indexed: 01/05/2023] Open
Abstract
DNA lesions that arrest replication can lead to rearrangements, mutations, or lethality when not processed accurately. After UV-induced DNA damage in Escherichia coli, RecA and several recF pathway proteins are thought to process arrested replication forks and ensure that replication resumes accurately. Here, we show that the RecJ nuclease and RecQ helicase, which partially degrade the nascent DNA at blocked replication forks, are required for the rapid recovery of DNA synthesis and prevent the potentially mutagenic bypass of UV lesions. In the absence of RecJ, or to a lesser extent RecQ, the recovery of replication is significantly delayed, and both the recovery and cell survival become dependent on translesion synthesis by polymerase V. The RecJ-mediated processing is proposed to restore the region containing the lesion to a form that allows repair enzymes to remove the blocking lesion and DNA synthesis to resume. In the absence of nascent DNA processing, polymerase V can synthesize past the lesion to prevent lethality, although this occurs with slower kinetics and a higher frequency of mutagenesis.
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Affiliation(s)
- Charmain T Courcelle
- Department of Biology, Portland State University, Box 751, Portland, OR 97207-0751, USA.
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Duan RS, Sit THC, Wong SSY, Wong RCW, Chow KH, Mak GC, Yam WC, Ng LT, Yuen KY, Ho PL. Escherichia coli Producing CTX-M β-Lactamases in Food Animals in Hong Kong. Microb Drug Resist 2006; 12:145-8. [PMID: 16922633 DOI: 10.1089/mdr.2006.12.145] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [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: 11/12/2022] Open
Abstract
A study was conducted to evaluate the occurrence of extended-spectrum beta-lactamases (ESBLs)-producing Escherichia coli from fecal samples of healthy food animals in Hong Kong. Rectal or cloacal swabs were obtained from cattle, pigs, chicken, ducks, geese, and pigeons in slaughterhouses or wholesale markets over a 5- month period in 2002. Antibiotic-containing medium was used for selective isolation of potentially ESBL-producing E. coli. Of 734 samples analyzed, six (2%) from pigs, three (3.1%) from cattle, and one (3%) from pigeons had E. coli strains with the ESBL phenotype. The ESBL content for the 10 isolates include CTXM- 3 (n = 4), CTX-M-13 (n = 3), CTX-M-14 (n = 2), and CTX-M-24 (n = 1). In five isolates, the bla (CTX-M) gene was encoded on transferable plasmids (60 or 90 kb), and the gene was found to transfer to E. coli (J53 or JP995) with frequencies of 10(7) to 10(3) per donor cells. The ten isolates had five distinct pulsotypes with some clonal spread. However, the isolates from the different kinds of animals were not clonally related. These findings imply that bacteria of animal origins may serve as reservoirs of some ESBL genes.
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Affiliation(s)
- R S Duan
- Division of Infectious Diseases, Department of Microbiology and Centre of Infection, University of Hong Kong, Hong Kong Special Administrative Region, China
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Salman Z, Kiefl RF, Chow KH, Hossain MD, Keeler TA, Kreitzman SR, Levy CDP, Miller RI, Parolin TJ, Pearson MR, Saadaoui H, Schultz JD, Smadella M, Wang D, MacFarlane WA. Near-surface structural phase transition of SrTiO3 studied with zero-field beta-detected nuclear spin relaxation and resonance. Phys Rev Lett 2006; 96:147601. [PMID: 16712119 DOI: 10.1103/physrevlett.96.147601] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2005] [Indexed: 05/09/2023]
Abstract
We demonstrate that zero-field beta-detected nuclear quadrupole resonance and spin relaxation of low energy (8)Li can be used as a sensitive local probe of structural phase transitions near a surface. We find that the transition near the surface of a SrTiO(3) single crystal occurs at T(c) approximately 150K, i.e., approximately 45K higher than T(c)bulk, and that the tetragonal domains formed below T(c) are randomly oriented.
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Affiliation(s)
- Z Salman
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
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Ho PL, Mak GC, Tse CWS, Chow KH, Cheung CHY. Invasive Haemophilus influenzae isolates with decreased levofloxacin susceptibility in Hong Kong. J Antimicrob Chemother 2005; 57:366. [PMID: 16387750 DOI: 10.1093/jac/dki466] [Citation(s) in RCA: 1] [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: 11/13/2022] Open
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Schultz BE, Chow KH, Hitti B, Kiefl RF, Lichti RL, Cox SFJ. Local structure of isolated positively charged muonium as an analog for the hydrogen ion in p-type GaAs. Phys Rev Lett 2005; 95:086404. [PMID: 16196878 DOI: 10.1103/physrevlett.95.086404] [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] [Subscribe] [Scholar Register] [Received: 05/15/2005] [Indexed: 05/04/2023]
Abstract
We determine the local structure of isolated positively charged muonium (Mu+) in heavily doped p-type GaAs based on muon level crossing resonance and zero applied field muon spin depolarization data. These measurements provide the first direct experimental confirmation that Mu+, and by analogy H+, is located within a stretched Ga-As bond. The distances between Mu+ and the nearest neighbor Ga and As atoms are estimated to be 1.83 +/- 0.10 A; and 1.76 +/- 0.10 A, respectively. These results are compared to existing theoretical calculations on the structure of hydrogen in GaAs and additionally provide data on the induced electric field gradients.
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Affiliation(s)
- B E Schultz
- Department of Physics, University of Alberta, Edmonton, Canada T6G 2J1
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Yam WC, Chan KH, Chow KH, Poon LLM, Lam HY, Yuen KY, Seto WH, Peiris JSM. Clinical evaluation of real-time PCR assays for rapid diagnosis of SARS coronavirus during outbreak and post-epidemic periods. J Clin Virol 2005; 33:19-24. [PMID: 15797361 PMCID: PMC7108323 DOI: 10.1016/j.jcv.2004.09.029] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2004] [Revised: 09/14/2004] [Accepted: 09/24/2004] [Indexed: 01/27/2023]
Abstract
BACKGROUND The protocols of WHO network laboratories facilitated development of rapid diagnosis for SARS coronavirus (CoV) using reverse transcription (RT)-PCR assays. However, several reports have shown that conventional and real-time PCR assays were very specific for SARS CoV but lack sensitivity depending on the assay, specimen, and time course of disease. OBJECTIVE To evaluate an automatic nucleic acid extraction system and two standardized real-time PCR assays for rapid diagnosis of SARS CoV during outbreak and post-epidemic periods in Hong Kong. STUDY DESIGN Specimens from clinically suspected SARS patients collected during outbreak and post-epidemic periods were tested by an automatic nucleic acid extraction system followed by our first generation conventional RT-PCR and two standardized real-time PCR assays (Artus GmbH, Germany and Roche Diagnostics, Germany). Paired serum samples were assayed for increasing titer against SARS CoV. RESULTS In the SARS epidemic, Artus and Roche PCR assays exhibited sensitivities of 87% and 85% for respiratory specimens (n = 64), 91% and 88% for stool (n = 44), and 82% for urine (n = 29). A specificity of 100% was exhibited by both PCR assays except Artus attained only a 92% specificity for stool. For post-epidemic period, no SARS CoV was identified among 56 respiratory specimens by all PCR assays. Inhibitors to PCR assays were detected at an average rate of 7-8% among 202 clinical specimens. CONCLUSION This study highlights the high throughput and performance of automatic RNA extraction in coordination with standardized real-time PCR assays suitable for large-scale routine diagnosis in case of future SARS epidemic. As no SARS CoV was detected among specimens collected during post-epidemic period, the positive predictive value of real-time PCR assays for detection of SARS CoV during low epidemic requires further evaluation.
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Affiliation(s)
- W C Yam
- Department of Microbiology, The University of Hong Kong, University Pathology Building, Queen Mary Hospital Compound, Pokfulam, Hong Kong SAR, PR China.
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48
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Ho PL, Ho AYM, Chow KH, Wong RCW, Duan RS, Ho WL, Mak GC, Tsang KW, Yam WC, Yuen KY. Occurrence and molecular analysis of extended-spectrum β-lactamase-producing Proteus mirabilis in Hong Kong, 1999–2002. J Antimicrob Chemother 2005; 55:840-5. [PMID: 15857942 DOI: 10.1093/jac/dki135] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [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: 11/14/2022] Open
Abstract
OBJECTIVES A study was conducted to evaluate the occurrence and characterization of extended-spectrum beta-lactamases (ESBLs) among blood isolates of Proteus mirabilis collected over a 4 year period in Hong Kong. METHODS Production of ESBLs among 99 consecutive and non-duplicate isolates was evaluated by the double-disc synergy test. The ESBLs were characterized by isoelectric focusing and PCR sequencing using specific primers. The epidemiological relationship of the isolates was studied by the Dienes test and PFGE. RESULTS ESBLs were identified in 13 isolates, from none in 1999-2000 and up to 18.5% (5/27) in 2001 and 25.8% (8/31) in 2002. The ESBL-producing isolates were more resistant to ceftriaxone than to ceftazidime, and were more likely than non-ESBL-producers to have resistance to ciprofloxacin (76.9% versus 14%) and gentamicin (38.5% versus 9.3%). The ESBL content included CTX-M-13 (n=8), CTX-M-14 (n=3), SHV-5 (n=2), TEM-11 (n=1), and an unidentified ESBL with a pI of 7.5. The Dienes test revealed that the genetic background in the 99 isolates was highly heterogeneous, with 54 distinct types among 92 isolates and seven were non-typeable. Among the 13 ESBL-producing isolates, five different backgrounds, including one cluster (Dienes-pulsotype A) with nine isolates, were identified by both Dienes test and PFGE, thus suggesting both clonal and multi-clonal spread of the CTX-M enzymes. CONCLUSIONS Our findings indicate the emergence of CTX-M enzymes among P. mirabilis in Hong Kong. More ESBL screening of this species is required to improve their recognition.
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Affiliation(s)
- P L Ho
- Division of Infectious Diseases, Department of Microbiology and Centre of Infection, The University of Hong Kong, Queen Mary Hospital, Pokfulam Road, Pokfulam, Hong Kong Special Administrative Region, China.
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Ho PL, Shek RHL, Chow KH, Duan RS, Mak GC, Lai EL, Yam WC, Tsang KW, Lai WM. Detection and characterization of extended-spectrum β-lactamases among bloodstream isolates of Enterobacter spp. in Hong Kong, 2000–2002. J Antimicrob Chemother 2005; 55:326-32. [PMID: 15681579 DOI: 10.1093/jac/dki010] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [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: 11/13/2022] Open
Abstract
OBJECTIVES A total of 139 consecutive and non-duplicate bloodstream isolates of Enterobacter spp. collected from inpatients in Hong Kong during 2000-2002 were studied for production of extended-spectrum beta-lactamases (ESBLs). METHODS All isolates were evaluated by the modified double-disc synergy test (m-DDST), the combined disc method (CDM) and the three-dimensional (3D) test. The m-DDST and CDM were modified by the use of cefepime discs. beta-Lactamases were characterized by isoelectric focusing and PCR sequencing using specific primers. RESULTS ESBLs were identified in nine isolates (overall 6.5%), including seven of 39 (17.9%) Enterobacter hormaechei, one of 27 (3.7%) Enterobacter aerogenes and the only Enterobacter intermedius strain. The E. intermedius strain was positive only in the 3D test but not in the other two tests. The other eight strains were positive in all three tests. No ESBL was detected in the other species, including non-hormaechei members of the Enterobacter cloacae complex (n=61), Enterobacter agglomerans (n=7), Enterobacter gergoviae (n=4) and Enterobacter sakazakii (n=1). The ESBL content included five different CTX-M enzymes (CTX-M-9, CTX-M-13, CTX-M-14, CTX-M-24 and a novel CTX-M-2-like beta-lactamase), SHV-12 (n=2) and unidentifiable ESBLs with a pI of 7.7 or 7.9 in two strains. The seven ESBL-producing E. hormaechei were genotyped by pulsed-field gel electrophoresis and were found to be unrelated to each other. In three of the CTX-M-producing strains, ISEcp1-like elements, including promoters for the beta-lactamase gene, were found. CONCLUSIONS Our data underscore the diversity of CTX-M enzymes among Enterobacter spp. in Hong Kong.
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Affiliation(s)
- P L Ho
- Division of Infectious Diseases, Department of Microbiology and Centre of Infection, United Christian Hospital, University of Hong Kong, Hong Kong SAR, China.
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Morris GD, Macfarlane WA, Chow KH, Salman Z, Arseneau DJ, Daviel S, Hatakeyama A, Kreitzman SR, Levy CDP, Poutissou R, Heffner RH, Elenewski JE, Greene LH, Kiefl RF. Depth-controlled beta-NMR of 8Li in a thin silver film. Phys Rev Lett 2004; 93:157601. [PMID: 15524941 DOI: 10.1103/physrevlett.93.157601] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2003] [Indexed: 05/24/2023]
Abstract
Depth-controlled beta-NMR can be used to probe the magnetic properties of thin films and interfaces on a nanometer length scale. A 30 keV beam of highly spin-polarized 8Li+ ions was slowed down and implanted into a 50 nm film of Ag deposited on a SrTiO3 substrate. A novel high field beta-NMR spectrometer was used to observe two well resolved resonances which are attributed to Li occupying substitutional and octahedral interstitial sites in the Ag lattice. The temperature dependence of the Knight shifts and spin relaxation rates are consistent with the Korringa law for a simple metal, implying that the NMR of implanted 8Li reflects the spin suspectibility of bulk metallic silver.
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Affiliation(s)
- G D Morris
- Los Alamos National Laboratory, K764, Los Alamos, New Mexico 87545, USA
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