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Zhang Y, Dho SE, Othman K, Simpson CD, Lapierre J, Bondoc A, McGlade CJ. Numb exon 9 inclusion regulates Integrinβ5 surface expression and promotes breast cancer metastasis. Oncogene 2022; 41:2079-2094. [PMID: 35181737 DOI: 10.1038/s41388-022-02225-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 01/14/2022] [Accepted: 02/01/2022] [Indexed: 01/07/2023]
Abstract
The endocytic adaptor protein Numb acts as a tumor suppressor through downregulation of oncogenic pathways in multiple cancer types. The identification of splicing alterations giving rise to changes in Numb protein isoform expression indicate that Numb also has tumor promoting activity, though the underlying mechanisms are unknown. Here we report that NUMB exon 9 inclusion, which results in production of a protein isoform with an additional 49 amino acids, is a feature of multiple cancer types including all subtypes of breast cancer and correlates with worse progression-free survival. Specific deletion of exon 9-included Numb isoforms (Exon9in) from breast cancer cells reduced cell growth and prevents spontaneous lung metastasis in a mouse model. Quantitative proteome profiling showed that loss of Exon9in causes downregulation of membrane receptors and adhesion molecules, as well as proteins involved in extracellular matrix organization and the epithelial-mesenchymal transition (EMT) state. In addition, exon 9 deletion caused remodeling of the endocytic network, decreased ITGβ5 surface localization, cell spreading on vitronectin and downstream signaling to ERK and SRC. Together these observations suggest that Exon9in isoform expression disrupts the endocytic trafficking functions of Numb, resulting in increased surface expression of ITGβ5 as well as other plasma membrane proteins to promote cell adhesion, EMT, and tumor metastasis.
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Affiliation(s)
- Yangjing Zhang
- Department of Medical Biophysics, University of Toronto, 610 University Avenue, Toronto, ON, M5G 2M9, Canada
- The Arthur and Sonia Labatt Brain Tumour Research Centre, 555 University Avenue, Toronto, ON, M5G 1X8, Canada
| | - Sascha E Dho
- The Arthur and Sonia Labatt Brain Tumour Research Centre, 555 University Avenue, Toronto, ON, M5G 1X8, Canada
- Program in Cell Biology, 555 University Avenue, Toronto, ON, M5G 1X8, Canada
| | - Kamal Othman
- Department of Medical Biophysics, University of Toronto, 610 University Avenue, Toronto, ON, M5G 2M9, Canada
- The Arthur and Sonia Labatt Brain Tumour Research Centre, 555 University Avenue, Toronto, ON, M5G 1X8, Canada
| | - Craig D Simpson
- SPARC BioCentre, The Hospital for Sick Children, 555 University Avenue, Toronto, ON, M5G 1X8, Canada
| | - Jessica Lapierre
- The Arthur and Sonia Labatt Brain Tumour Research Centre, 555 University Avenue, Toronto, ON, M5G 1X8, Canada
- Program in Cell Biology, 555 University Avenue, Toronto, ON, M5G 1X8, Canada
| | - Andrew Bondoc
- The Arthur and Sonia Labatt Brain Tumour Research Centre, 555 University Avenue, Toronto, ON, M5G 1X8, Canada
- Program in Cell Biology, 555 University Avenue, Toronto, ON, M5G 1X8, Canada
| | - C Jane McGlade
- Department of Medical Biophysics, University of Toronto, 610 University Avenue, Toronto, ON, M5G 2M9, Canada.
- The Arthur and Sonia Labatt Brain Tumour Research Centre, 555 University Avenue, Toronto, ON, M5G 1X8, Canada.
- Program in Cell Biology, 555 University Avenue, Toronto, ON, M5G 1X8, Canada.
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Wybenga-Groot LE, Tench AJ, Simpson CD, Germain JS, Raught B, Moran MF, McGlade CJ. SLAP2 Adaptor Binding Disrupts c-CBL Autoinhibition to Activate Ubiquitin Ligase Function. J Mol Biol 2021; 433:166880. [PMID: 33617900 DOI: 10.1016/j.jmb.2021.166880] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 02/05/2021] [Accepted: 02/12/2021] [Indexed: 10/22/2022]
Abstract
CBL is a RING type E3 ubiquitin ligase that functions as a negative regulator of tyrosine kinase signaling and loss of CBL E3 function is implicated in several forms of leukemia. The Src-like adaptor proteins (SLAP/SLAP2) bind to CBL and are required for CBL-dependent downregulation of antigen receptor, cytokine receptor, and receptor tyrosine kinase signaling. Despite the established role of SLAP/SLAP2 in regulating CBL activity, the nature of the interaction and the mechanisms involved are not known. To understand the molecular basis of the interaction between SLAP/SLAP2 and CBL, we solved the crystal structure of CBL tyrosine kinase binding domain (TKBD) in complex with SLAP2. The carboxy-terminal region of SLAP2 adopts an α-helical structure which binds in a cleft between the 4H, EF-hand, and SH2 domains of the TKBD. This SLAP2 binding site is remote from the canonical TKBD phospho-tyrosine peptide binding site but overlaps with a region important for stabilizing CBL in its autoinhibited conformation. In addition, binding of SLAP2 to CBL in vitro activates the ubiquitin ligase function of autoinhibited CBL. Disruption of the CBL/SLAP2 interface through mutagenesis demonstrated a role for this protein-protein interaction in regulation of CBL E3 ligase activity in cells. Our results reveal that SLAP2 binding to a regulatory cleft of the TKBD provides an alternative mechanism for activation of CBL ubiquitin ligase function.
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Affiliation(s)
- Leanne E Wybenga-Groot
- The Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada; Program in Cell Biology, The Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada; SPARC BioCentre, The Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada.
| | - Andrea J Tench
- The Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada; Program in Cell Biology, The Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada; Department of Medical Biophysics, University of Toronto, 610 University Avenue, Toronto, ON M5G 2M9, Canada
| | - Craig D Simpson
- The Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada; Program in Cell Biology, The Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada
| | - Jonathan St Germain
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON M5G 1L7, Canada
| | - Brian Raught
- Department of Medical Biophysics, University of Toronto, 610 University Avenue, Toronto, ON M5G 2M9, Canada; Princess Margaret Cancer Centre, University Health Network, Toronto, ON M5G 1L7, Canada
| | - Michael F Moran
- Program in Cell Biology, The Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada; SPARC BioCentre, The Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada; Department of Molecular Genetics, 1 King's College Circle, Toronto, ON M5S 1A8, Canada
| | - C Jane McGlade
- The Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada; Program in Cell Biology, The Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada; Department of Medical Biophysics, University of Toronto, 610 University Avenue, Toronto, ON M5G 2M9, Canada.
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Simpson CD. Temperature and mouth opening. Br Dent J 2020; 229:209. [PMID: 32855448 DOI: 10.1038/s41415-020-2070-0] [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: 11/09/2022]
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van de Kooij B, Creixell P, van Vlimmeren A, Joughin BA, Miller CJ, Haider N, Simpson CD, Linding R, Stambolic V, Turk BE, Yaffe MB. Comprehensive substrate specificity profiling of the human Nek kinome reveals unexpected signaling outputs. eLife 2019; 8:44635. [PMID: 31124786 PMCID: PMC6570481 DOI: 10.7554/elife.44635] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 05/13/2019] [Indexed: 12/25/2022] Open
Abstract
Human NimA-related kinases (Neks) have multiple mitotic and non-mitotic functions, but few substrates are known. We systematically determined the phosphorylation-site motifs for the entire Nek kinase family, except for Nek11. While all Nek kinases strongly select for hydrophobic residues in the −3 position, the family separates into four distinct groups based on specificity for a serine versus threonine phospho-acceptor, and preference for basic or acidic residues in other positions. Unlike Nek1-Nek9, Nek10 is a dual-specificity kinase that efficiently phosphorylates itself and peptide substrates on serine and tyrosine, and its activity is enhanced by tyrosine auto-phosphorylation. Nek10 dual-specificity depends on residues in the HRD+2 and APE-4 positions that are uncommon in either serine/threonine or tyrosine kinases. Finally, we show that the phosphorylation-site motifs for the mitotic kinases Nek6, Nek7 and Nek9 are essentially identical to that of their upstream activator Plk1, suggesting that Nek6/7/9 function as phospho-motif amplifiers of Plk1 signaling.
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Affiliation(s)
- Bert van de Kooij
- Department of Biology, Massachusetts Institute of Technology, Cambridge, United States.,Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, United States.,Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, United States.,MIT Center for Precision Cancer Medicine, Massachusetts Institute of Technology, Cambridge, United States
| | - Pau Creixell
- Department of Biology, Massachusetts Institute of Technology, Cambridge, United States.,Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, United States.,Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, United States.,MIT Center for Precision Cancer Medicine, Massachusetts Institute of Technology, Cambridge, United States
| | - Anne van Vlimmeren
- Department of Biology, Massachusetts Institute of Technology, Cambridge, United States.,Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, United States.,Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, United States.,MIT Center for Precision Cancer Medicine, Massachusetts Institute of Technology, Cambridge, United States
| | - Brian A Joughin
- Department of Biology, Massachusetts Institute of Technology, Cambridge, United States.,Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, United States.,Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, United States.,MIT Center for Precision Cancer Medicine, Massachusetts Institute of Technology, Cambridge, United States
| | - Chad J Miller
- Department of Pharmacology, Yale School of Medicine, New Haven, United States
| | - Nasir Haider
- Department of Medical Biophysics, University of Toronto, Toronto, Canada
| | - Craig D Simpson
- Biotech Research and Innovation Center, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Rune Linding
- Biotech Research and Innovation Center, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Vuk Stambolic
- Department of Medical Biophysics, University of Toronto, Toronto, Canada.,Princess Margaret Cancer Center, University Health Network, Toronto, Canada
| | - Benjamin E Turk
- Department of Pharmacology, Yale School of Medicine, New Haven, United States
| | - Michael B Yaffe
- Department of Biology, Massachusetts Institute of Technology, Cambridge, United States.,Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, United States.,Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, United States.,MIT Center for Precision Cancer Medicine, Massachusetts Institute of Technology, Cambridge, United States.,Department of Surgery, Beth Israel Deaconess Medical Center, Divisions of Acute Care Surgery, Trauma, and Critical Care and Surgical Oncology, Harvard Medical School, Boston, United States
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Affiliation(s)
- C D Simpson
- Department of Oral Surgery, Edinburgh Dental Institute, UK.
| | - N Rahman
- Department of Oral Surgery, Edinburgh Dental Institute, UK.
| | - P-J Lamey
- Department of Oral Medicine, Edinburgh Dental Institute, UK.
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Creixell P, Schoof EM, Simpson CD, Longden J, Miller CJ, Lou HJ, Perryman L, Cox TR, Zivanovic N, Palmeri A, Wesolowska-Andersen A, Helmer-Citterich M, Ferkinghoff-Borg J, Itamochi H, Bodenmiller B, Erler JT, Turk BE, Linding R. Kinome-wide decoding of network-attacking mutations rewiring cancer signaling. Cell 2015; 163:202-17. [PMID: 26388441 PMCID: PMC4644236 DOI: 10.1016/j.cell.2015.08.056] [Citation(s) in RCA: 100] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Revised: 04/09/2015] [Accepted: 08/12/2015] [Indexed: 12/17/2022]
Abstract
Cancer cells acquire pathological phenotypes through accumulation of mutations that perturb signaling networks. However, global analysis of these events is currently limited. Here, we identify six types of network-attacking mutations (NAMs), including changes in kinase and SH2 modulation, network rewiring, and the genesis and extinction of phosphorylation sites. We developed a computational platform (ReKINect) to identify NAMs and systematically interpreted the exomes and quantitative (phospho-)proteomes of five ovarian cancer cell lines and the global cancer genome repository. We identified and experimentally validated several NAMs, including PKCγ M501I and PKD1 D665N, which encode specificity switches analogous to the appearance of kinases de novo within the kinome. We discover mutant molecular logic gates, a drift toward phospho-threonine signaling, weakening of phosphorylation motifs, and kinase-inactivating hotspots in cancer. Our method pinpoints functional NAMs, scales with the complexity of cancer genomes and cell signaling, and may enhance our capability to therapeutically target tumor-specific networks. Mutations perturbing signaling networks are systematically classified and interpreted Several such functional mutations are identified in cancer and experimentally validated The results suggest that a single point mutant can have profound signaling effects Systematic interpretation of genomic data may assist future precision-medicine efforts
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Affiliation(s)
- Pau Creixell
- Department of Systems Biology, Technical University of Denmark, 2800 Lyngby, Denmark
| | - Erwin M Schoof
- Department of Systems Biology, Technical University of Denmark, 2800 Lyngby, Denmark
| | - Craig D Simpson
- Biotech Research and Innovation Centre (BRIC), University of Copenhagen (UCPH), 2200 Copenhagen, Denmark
| | - James Longden
- Biotech Research and Innovation Centre (BRIC), University of Copenhagen (UCPH), 2200 Copenhagen, Denmark
| | - Chad J Miller
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Hua Jane Lou
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Lara Perryman
- Biotech Research and Innovation Centre (BRIC), University of Copenhagen (UCPH), 2200 Copenhagen, Denmark
| | - Thomas R Cox
- Biotech Research and Innovation Centre (BRIC), University of Copenhagen (UCPH), 2200 Copenhagen, Denmark
| | - Nevena Zivanovic
- Institute of Molecular Life Sciences, University of Zurich, 8057 Zurich, Switzerland
| | - Antonio Palmeri
- Centre for Molecular Bioinformatics, University of Rome Tor Vergata, 00133 Rome, Italy
| | | | | | - Jesper Ferkinghoff-Borg
- Biotech Research and Innovation Centre (BRIC), University of Copenhagen (UCPH), 2200 Copenhagen, Denmark
| | | | - Bernd Bodenmiller
- Institute of Molecular Life Sciences, University of Zurich, 8057 Zurich, Switzerland
| | - Janine T Erler
- Biotech Research and Innovation Centre (BRIC), University of Copenhagen (UCPH), 2200 Copenhagen, Denmark
| | - Benjamin E Turk
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Rune Linding
- Department of Systems Biology, Technical University of Denmark, 2800 Lyngby, Denmark; Biotech Research and Innovation Centre (BRIC), University of Copenhagen (UCPH), 2200 Copenhagen, Denmark.
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Mamaghani S, Simpson CD, Cao PM, Cheung M, Chow S, Bandarchi B, Schimmer AD, Hedley DW. Glycogen synthase kinase-3 inhibition sensitizes pancreatic cancer cells to TRAIL-induced apoptosis. PLoS One 2012; 7:e41102. [PMID: 22829912 PMCID: PMC3400624 DOI: 10.1371/journal.pone.0041102] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [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: 12/02/2011] [Accepted: 06/21/2012] [Indexed: 12/16/2022] Open
Abstract
Tumor necrosis factor-related apoptosis inducing ligand (TRAIL) induces apoptosis in a variety of cancer cell lines with little or no effect on normal cells. However, its effect is limited as some cancers including pancreatic cancer show de novo resistance to TRAIL induced apoptosis. In this study we report that GSK-3 inhibition using the pharmacologic agent AR-18, enhanced TRAIL sensitivity in a range of pancreatic and prostate cancer cell lines. This sensitization was found to be caspase-dependent, and both pharmacological and genetic knock-down of GSK-3 isoforms resulted in apoptotic features as shown by cleavage of PARP and caspase-3. Elevated levels of reactive oxygen intermediates and disturbance of mitochondrial membrane potential point to a mitochondrial amplification loop for TRAIL-induced apoptosis after GSK-3 inhibition. Consistent with this, overexpression of anti-apoptotic mitochondrial targets such as Bcl-XL, Mcl-1, and Bcl-2 rescued PANC-1 and PPC-1 cells from TRAIL sensitization. However, overexpression of the caspase-8 inhibitor CrmA also inhibited the sensitizing effects of GSK-3 inhibitor, suggesting an additional role for GSK-3 that inhibits death receptor signaling. Acute treatment of mice bearing PANC-1 xenografts with a combination of AR-18 and TRAIL also resulted in a significant increase in apoptosis, as measured by caspase-3 cleavage. Sensitization to TRAIL occurred despite an increase in β-catenin due to GSK-3 inhibition, suggesting that the approach might be effective even in cancers with dysregulated β-catenin. These results suggest that GSK-3 inhibitors might be effectively combined with TRAIL for the treatment of pancreatic cancer.
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Affiliation(s)
- Shadi Mamaghani
- Division of Applied Molecular Oncology, University Health Network, Toronto, Ontario, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
- Ontario Cancer Institute, Princess Margaret Hospital, Toronto, Ontario, Canada
| | - Craig D. Simpson
- Ontario Cancer Institute, Princess Margaret Hospital, Toronto, Ontario, Canada
| | - Pinjiang M. Cao
- Division of Applied Molecular Oncology, University Health Network, Toronto, Ontario, Canada
- Ontario Cancer Institute, Princess Margaret Hospital, Toronto, Ontario, Canada
| | - May Cheung
- Division of Applied Molecular Oncology, University Health Network, Toronto, Ontario, Canada
- Ontario Cancer Institute, Princess Margaret Hospital, Toronto, Ontario, Canada
| | - Sue Chow
- Division of Applied Molecular Oncology, University Health Network, Toronto, Ontario, Canada
- Ontario Cancer Institute, Princess Margaret Hospital, Toronto, Ontario, Canada
| | - Bizhan Bandarchi
- Ontario Cancer Institute, Princess Margaret Hospital, Toronto, Ontario, Canada
| | - Aaron D. Schimmer
- Ontario Cancer Institute, Princess Margaret Hospital, Toronto, Ontario, Canada
- Department of Medical Oncology and Hematology, Princess Margaret Hospital, Toronto, Ontario, Canada
| | - David W. Hedley
- Division of Applied Molecular Oncology, University Health Network, Toronto, Ontario, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
- Ontario Cancer Institute, Princess Margaret Hospital, Toronto, Ontario, Canada
- Department of Medical Oncology and Hematology, Princess Margaret Hospital, Toronto, Ontario, Canada
- * E-mail:
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Simpson CD, Hurren R, MacLean N, Eberhard Y, Ketela T, Moffat J, Schimmer AD. Abstract A22: A genome-wide shRNA screen identifies α/β hydrolase domain containing 4 (ABHD4) as a novel regulator of anoikis resistance. Mol Cancer Ther 2011. [DOI: 10.1158/1535-7163.targ-11-a22] [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
Acquisition of resistance to anchorage dependant cell death, a process termed anoikis, is a requirement for cancer cell metastasis. However, the molecular determinants of anoikis resistance and sensitivity are poorly understood. To better understand resistance to anoikis we conducted a genome wide lentiviral shRNA screen to identify genes whose knockdown render RWPE-1 prostate cells resistant to anoikis. RWPE-1 cells are a non-malignant prostate cell line that undergo cell death upon detachment from extracellular matrix. To identify genetic regulators of anoikis, RWPE-1 cells were infected with a pooled lentiviral hairpin shRNA library with 54,021 hairpins targeting 11,255 genes. After infection, cells were cultured in suspension conditions for three weeks and an anoikis-resistant cell population was selected. From this population, genomic DNA was isolated and shRNA sequences were amplified and sequenced. Thirty four shRNA sequences reproducibly protected RWPE-1 cells from anoikis after culture under suspension conditions. We selected α/β hydrolase domain containing 4 (ABHD4) for further analysis as it conferred the greatest protection to anoikis in our screening assays. To validate the effects of ABHD4 knockdown on anoikis resistance, we infected RWPE-1 with 2 independent shRNA targeting ABHD4 or control sequences. We also over-expressed ABHD4 in wild type cells. Finally, we co-infected cells with ABDH4 cDNA and shRNA as a rescue experiment to demonstrate on-target activity. Target knockdown or over-expression after infection was confirmed by Q-RTPCR or immunoblotting. Using two independent shRNA, knockdown of ABHD4 inhibited anoikis as evidence by increased clonogenic growth compared to cells infected with control sequences. Demonstrating an on-target effect, rescue of ABHD4 expression returned levels of clonogenic growth to wild type levels. Finally, over-expression of ABHD4 increased sensitivity to anoikis and less clonogenic growth was observed in these cells compared to control cells.
Resistance to anoikis after ABHD4 knockdown was associated with decreased cleavage of PARP and decreased activation of caspases-3, 8 and 9, but was independent in changes of FLIP expression. Interesting, resistance to anoikis after ABHD4 knockdown was independent of the known role of ABHD4 in the anandamide synthesis pathway and the generation of glycerophospho-N-acyl ethanolamines. Thus, reductions in the levels of ABHD4 confer resistance to anoikis while over-expression of the target enhances anoikis in the anoikis-sensitive cell line RWPE-1. As such, we have identified a novel genetic regulator of anoikis sensitivity.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr A22.
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Affiliation(s)
| | - Rose Hurren
- 1Ontario Cancer Institute, Toronto, ON, Canada
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Zavareh RB, Hurren R, Gronda M, Sukhai MA, Simpson CD, Wang X, MacLean NA, Ketela T, Moffat J, Rose DR, Schachter H, Dennis JW, Schimmer AD. Abstract 1484: Inhibition of the glycosylation enzyme Mgat1 blocks migration, invasion and metastasis of malignant cells. Cancer Res 2011. [DOI: 10.1158/1538-7445.am2011-1484] [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
N-acetylglucosaminyltransferase I (Mgat1) is the enzyme that initiates the biosynthesis of hybrid and complex N-glycans in medial golgi. As such, it regulates N-glycosylation, a post-translational modification that alters the localization and function of cell surface proteins. Aberrant activity of the N-glycosylation pathway is seen frequently in malignant cells and contributes to their metastatic potential. Here, we have evaluated the effects of Mgat1 inhibition in malignant cells.
We knocked down Mgat1 with two independent shRNA in Hela human cervical cancer cells. Target knockdown and inhibition was confirmed by demonstrating mRNA knockdown, decreased cell-surface lectin staining, and inhibition of enzymatic activity. Knockdown of Mgat1 did not induce cell death or inhibit proliferation.
Complex N-glycans influence cell migration and invasion. Therefore, we investigated the effect of Mgat1 knockdown on these glycosylation-mediated processes. Hela cells with Mgat1 knockdown and control shRNA were seeded into invasion chambers. Twenty four hours after seeding, we measured cell migration through uncoated chambers and cell invasion through Matrigel-coated chambers. Compared to control shRNA, Mgat1 knockdown significantly decreased Hela cells migration and invasion.
ιntegrins influence cell migration and invasion and are N-glycosylated. Therefore, to begin to understand the mechanism by which Mgat1 knockdown inhibits cell migration and invasion, we examined changes in the cell surface expression of β1 integrins. By confocal microscopy, knockdown of Mgat1 decreased cell surface expression of β1 integrins and increased their localization around the nucleus.
To assess the effects of Mgat1 on metastasis in vivo, we knocked down Mgat1 with shRNA in RFP-labeled PC3N7 prostate cancer cells. Mgat1 knockdown or control cells were then injected orthotopically into the prostate gland of sublethally irradiated SCID mice. Four weeks after injection, mice were sacrificed and distant tumor formation was imaged with fluorescent microscopy. Mgat1 knockdown decreased the median number of tumors that had metastasized to the lung more than three-fold compared to control.
Our preclinical studies, suggest a role for Mgat1 in cancer cell metastasis. Therefore, we examined the association between Mgat1 mRNA expression in primary tumors and the incidence of subsequent metastasis. By analyzing publically available gene expression array data sets from patients with breast cancer, we determined that patients with the lowest levels of Mgat1 mRNA in their primary tumors were least likely to develop metastatic disease after therapy.
In summary, this work highlights the role of the N-glycosyltransferase Mgat1 in cancer cell metastasis. As such, Mgat1 may be a novel target for anti-cancer therapies and levels of Mgat1 in primary tumors may help predict the risk of developing metastatic disease.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1484. doi:10.1158/1538-7445.AM2011-1484
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Affiliation(s)
| | - Rose Hurren
- 1Ontario Cancer Institute, Toronto, Ontario, Canada
| | | | | | | | | | | | - Troy Ketela
- 2Centre for Cellular and Biomolecular Research, Toronto, Ontario, Canada
| | - Jason Moffat
- 2Centre for Cellular and Biomolecular Research, Toronto, Ontario, Canada
| | | | | | - James W. Dennis
- 5Samuel Lunenfeld Research Institute, Toronto, Ontario, Canada
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Skrtic M, Spagnuolo P, Wang X, Gronda M, Hurren R, Simpson CD, Fonseca S, Datti A, Wang JCY, Dick JE, Wrana JL, Kelley SO, Schimmer AD. Abstract 4538: Inhibition of mitochondrial protein synthesis with antimicrobial tigecycline preferentially induces cell death in leukemia cells. Cancer Res 2010. [DOI: 10.1158/1538-7445.am10-4538] [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
To identify known drugs with unrecognized anti-leukemia activity, we compiled a library of 500 on patent and off patent compounds, and screened it to identify compounds cytotoxic to leukemia cell lines. From this screen we identified Tigecycline, an antibiotic approved for the treatment of cutaneous and intra-abdominal infections.
Tigecycline induced cell death in leukemia cell lines (LD50 3 to 8 μM, n = 6 cell lines) and primary Acute Myeloid Leukemia (AML) patient samples (LD50 5-10 μM, n = 7), preferentially over normal hematopoietic cells (10% cell death at 20 μM, n = 4) by MTS assays and Annexin V staining. Likewise, in colony formation assays, Tigecycline (5μM) reduced the clonogenic growth of primary AML patient samples (n = 4) by 95±1.5 %, demonstrating an effect on leukemia progenitor cells. In contrast, 5 μM of Tigecycline reduced the clonogenic growth of normal hematopoetic cells by 34± 5% (n = 5). Although Tigecycline is structurally related to tetracycline and minocycline, these drugs were not cytotoxic towards AML cell lines up to 25 μM. Thus, Tigecycline appears preferentially cytotoxic to leukemia cells at pharmacologically achievable concentrations.
Given the anti-leukemic effects of Tigecycline in vitro, we evaluated the efficacy of Tigecycline as a potential anti-leukemic agent in vivo. Mice injected subcutaneously with OCI-AML2 leukemia cells were treated with Tigecycline 50 mg/kg i.p. daily. Compared to control, Tigecycline decreased tumour mass and volume without toxicity. We also assessed the effect of Tigecycline on primary AML stem cells defined by their ability to initiate leukemic engraftment in vivo. NOD-SCID mice were injected intra-femorally with primary AML cells. Two weeks after injection, mice were treated with Tigecycline 50 mg/kg i.p. daily for two weeks. After treatment, engraftment of human AML cells was measured by flow cytometry. Compared to control, Tigecycline decreased engraftment of AML cells without toxicity.
Tigecycline binds and inhibits the bacterial 30S ribosome. Bacterial ribosomes are more homologous to mitochondrial ribosomes than cytosolic ribosomes, so we compared the effects of Tigecycline on mitochondrial and cytosolic protein synthesis. At times preceding the onset of cell death, Tigecycline decreased levels of the mitochondrial protein Cox-1. In contrast, it did not decrease the expression of cytosolic short half-life proteins Bcl-XL and XIAP, suggesting a preferential effect on mitochondrial protein synthesis.
Thus, Tigecycline demonstrated preclinical activity through a mechanism related to mitochondrial protein synthesis inhibition. Moreover, Tigecycline appeared cytotoxic to leukemia stem cells over normal hematopoetic stem cells. Given its prior pharmacology and toxicology testing, Tigecycline could be rapidly repositioned for a new anti-leukemic indication.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4538.
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Affiliation(s)
- Marko Skrtic
- 1Princess Margaret Hospital, Ontario Cancer Institute, Toronto, Ontario, Canada
| | - Paul Spagnuolo
- 1Princess Margaret Hospital, Ontario Cancer Institute, Toronto, Ontario, Canada
| | - Xiaoming Wang
- 1Princess Margaret Hospital, Ontario Cancer Institute, Toronto, Ontario, Canada
| | - Marcela Gronda
- 1Princess Margaret Hospital, Ontario Cancer Institute, Toronto, Ontario, Canada
| | - Rose Hurren
- 1Princess Margaret Hospital, Ontario Cancer Institute, Toronto, Ontario, Canada
| | - Craig D. Simpson
- 1Princess Margaret Hospital, Ontario Cancer Institute, Toronto, Ontario, Canada
| | - Sonali Fonseca
- 2Department of Pharmaceutical Sciences, Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
| | - Alessandro Datti
- 3Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
| | - Jean C Y Wang
- 4Division of Stem Cell and Developmental Biology, University Health Network, Toronto, Ontario, Canada
| | - John E. Dick
- 4Division of Stem Cell and Developmental Biology, University Health Network, Toronto, Ontario, Canada
| | - Jeffrey L. Wrana
- 3Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
| | - Shana O. Kelley
- 2Department of Pharmaceutical Sciences, Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
| | - Aaron D. Schimmer
- 1Princess Margaret Hospital, Ontario Cancer Institute, Toronto, Ontario, Canada
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Wood TE, Dalili S, Simpson CD, Sukhai MA, Hurren R, Anyiwe K, Mao X, Suarez Saiz F, Gronda M, Eberhard Y, MacLean N, Ketela T, Reed JC, Moffat J, Minden MD, Batey RA, Schimmer AD. Selective Inhibition of Histone Deacetylases Sensitizes Malignant Cells to Death Receptor Ligands. Mol Cancer Ther 2010; 9:246-56. [DOI: 10.1158/1535-7163.mct-09-0495] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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13
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Neitzel R, Naeher LP, Paulsen M, Dunn K, Stock A, Simpson CD. Biological monitoring of smoke exposure among wildland firefighters: a pilot study comparing urinary methoxyphenols with personal exposures to carbon monoxide, particular matter, and levoglucosan. J Expo Sci Environ Epidemiol 2009; 19:349-358. [PMID: 18446186 DOI: 10.1038/jes.2008.21] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2007] [Accepted: 03/07/2008] [Indexed: 05/26/2023]
Abstract
Urinary methoxyphenols (MPs) have been proposed as biomarkers of woodsmoke exposure. However, few field studies have been undertaken to evaluate the relationship between woodsmoke exposure and urinary MP concentrations. We conducted a pilot study at the US Forest Service-Savannah River Site, in which carbon monoxide (CO), levoglucosan (LG), and particulate matter (PM(2.5)) exposures were measured in wildland firefighters on prescribed burn days. Pre- and post-shift urine samples were collected from each subject, and cross-shift changes in creatinine-corrected urinary MP concentrations were calculated. Correlations between exposure measures and creatine-adjusted urinary MP concentrations were explored, and regression models were developed relating changes in urinary MP concentrations to measured exposure levels. Full-shift measurements were made on 13 firefighters over 20 work shifts in winter 2004 at the US Forest Service Savannah River site, a National Environmental Research Park. The average workshift length across the 20 measured shifts was 701+/-95 min. LG and CO exposures were significantly correlated for samples where the filter measurement captured at least 60% of the work shift (16 samples), as well as for the smaller set of full-shift exposure samples (n=9). PM(2.5) and CO exposures were not significantly correlated, and LG and PM(2.5) exposures were only significantly correlated for samples representing at least 60% of the work shift. Creatinine-corrected urinary concentrations for 20 of the 22 MPs showed cross-shift increases, with 14 of these changes showing statistical significance. Individual and summed creatinine-adjusted guaiacol urinary MPs were highly associated with CO (and, to a lesser degree, LG) exposure levels, and random-effects regression models including CO and LG exposure levels explained up to 80% of the variance in cross-shift changes in summed creatinine-adjusted guaiacol urinary MP concentrations. Although limited by the small sample size, this pilot study demonstrates that urinary MP concentrations may be effective biomarkers of occupational exposure to wood smoke among wildland firefighters.
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Affiliation(s)
- R Neitzel
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington 98195-7234, USA
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14
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Simpson CD, Mawji IA, Anyiwe K, Williams MA, Wang X, Venugopal AL, Gronda M, Hurren R, Cheng S, Serra S, Zavareh RB, Datti A, Wrana JL, Ezzat S, Schimmer AD. Inhibition of the Sodium Potassium Adenosine Triphosphatase Pump Sensitizes Cancer Cells to Anoikis and Prevents Distant Tumor Formation. Cancer Res 2009; 69:2739-47. [DOI: 10.1158/0008-5472.can-08-2530] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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15
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Etzkorn JM, Davey NG, Thompson AJ, Creba AS, Leblanc CW, Simpson CD, Krogh ET, Gill CG. The Use of MIMS-MS-MS in field locations as an on-line quantitative environmental monitoring technique for trace contaminants in air and water. J Chromatogr Sci 2009; 47:57-66. [PMID: 19161658 DOI: 10.1093/chromsci/47.1.57] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Membrane introduction mass spectrometry (MIMS) is emerging as an important technique for on-line, real-time environmental monitoring. Because MIMS interfaces are simple and robust, they are ideally suited for operation in MS instrumentation used for in-field applications. We report the use of an on-line permeation tube to continuously infuse an isotopically labeled internal standard for continuous quantitative determinations in atmospheric and aqueous samples without the need for off-line calibration. This approach also provides important information on the operational performance of the analytical system during multi-day deployments. We report measured signal stability during on-line deployments in air and water of 7% based on variation of the internal standard response and have used this technique to quantify BTEX (benzene, toluene, ethylbenzenes, and xylenes), pinenes, naphthalene and 2-methoxyphenol (guaiacol) in urban air plumes at parts-per-billion by volume levels. Presented are several recent applications of MIMS-MS-MS for on-line environmental monitoring in atmospheric and aqueous environmental samples demonstrating laboratory, remote and mobile deployments. We also present the use of a thermally assisted MIMS interface for the direct measurement of polyaromatic hydrocarbons, alkylphenols, and other SVOCs in the low ppb range in aqueous environmental samples and discuss improvements in both the sensitivity and response times for selected SVOCs. The work presented in this paper represents significant improvements in field deployable mass spectrometric techniques, which can be applied to direct on-site analytical measurements of VOC and SVOCs in environmental samples.
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Affiliation(s)
- J M Etzkorn
- Applied Environmental Research Laboratories (AERL), Department of Chemistry, Vancouver Island University, 900 Fifth Street, Nanaimo, British Columbia, Canada
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16
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Wood TE, Dalili S, Simpson CD, Hurren R, Mao X, Saiz FS, Gronda M, Eberhard Y, Minden MD, Bilan PJ, Klip A, Batey RA, Schimmer AD. A novel inhibitor of glucose uptake sensitizes cells to FAS-induced cell death. Mol Cancer Ther 2008; 7:3546-55. [PMID: 19001437 DOI: 10.1158/1535-7163.mct-08-0569] [Citation(s) in RCA: 134] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Evasion of death receptor ligand-induced apoptosis is an important contributor to cancer development and progression. Therefore, molecules that restore sensitivity to death receptor stimuli would be important tools to better understand this biological pathway and potential leads for therapeutic adjuncts. Previously, the small-molecule N-[4-chloro-3-(trifluoromethyl)phenyl]-3-oxobutanamide (fasentin) was identified as a chemical sensitizer to the death receptor stimuli FAS and tumor necrosis factor apoptosis-inducing ligand, but its mechanism of action was unknown. Here, we determined that fasentin alters expression of genes associated with nutrient and glucose deprivation. Consistent with this finding, culturing cells in low-glucose medium recapitulated the effects of fasentin and sensitized cells to FAS. Moreover, we showed that fasentin inhibited glucose uptake. Using virtual docking studies with a homology model of the glucose transport protein GLUT1, fasentin interacted with a unique site in the intracellular channel of this protein. Additional chemical studies with other GLUT inhibitors and analogues of fasentin supported a role for partial inhibition of glucose transport as a mechanism to sensitize cells to death receptor stimuli. Thus, fasentin is a novel inhibitor of glucose transport that blocks glucose uptake and highlights a new mechanism to sensitize cells to death ligands.
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Affiliation(s)
- Tabitha E Wood
- Princess Margaret Hospital, Ontario Cancer Institute, 610 University Avenue, Toronto, Ontario, Canada
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17
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Beheshti Zavareh R, Lau KS, Hurren R, Datti A, Ashline DJ, Gronda M, Cheung P, Simpson CD, Liu W, Wasylishen AR, Boutros PC, Shi H, Vengopal A, Jurisica I, Penn LZ, Reinhold VN, Ezzat S, Wrana J, Rose DR, Schachter H, Dennis JW, Schimmer AD. Inhibition of the sodium/potassium ATPase impairs N-glycan expression and function. Cancer Res 2008; 68:6688-97. [PMID: 18701493 DOI: 10.1158/0008-5472.can-07-6833] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [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
Aberrant N-linked glycans promote the malignant potential of cells by enhancing the epithelial-to-mesenchymal transition and the invasive phenotype. To identify small molecule inhibitors of N-glycan biosynthesis, we developed a chemical screen based on the ability of the tetravalent plant lectin L-phytohemagglutinin (L-PHA) to bind and crosslink surface glycoproteins with beta1,6GlcNAc-branched complex type N-glycans and thereby induce agglutination and cell death. In this screen, Jurkat cells were treated with a library of off-patent chemicals (n = 1,280) to identify molecules that blocked L-PHA-induced death. The most potent hit from this screen was the cardiac glycoside (CG) dihydroouabain. In secondary assays, a panel of CGs was tested for their effects on L-PHA-induced agglutination and cell death. All of the CGs tested inhibited L-PHA-induced death in Jurkat cells, and the most potent CG tested was digoxin with an EC(50) of 60 +/- 20 nmol/L. Digoxin also increased the fraction of some concanavalin A-binding N-glycans. Using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, digoxin specifically increased GlcNAc(1)Man(3)GlcNAc(2)Fuc(1) and GlcNAc(2)Man(3)GlcNAc(2)Fuc(1) oligosaccharides demonstrating an impairment of the N-glycan pathway. Consistent with this effect on the N-glycan pathway, digoxin inhibited N-glycosylation-mediated processes of tumor cell migration and invasion. Furthermore, digoxin prevented distant tumor formation in two mouse models of metastatic prostate cancer. Thus, taken together, our high throughput screen identified CGs as modifiers of the N-glycan pathway. These molecules can be used as tools to better understand the role of N-glycans in normal and malignant cells. Moreover, these results may partly explain the anticancer effect of CGs in cardiovascular patients.
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Abstract
As a barrier to metastases, cells normally undergo apoptosis after they lose contact with their extra cellular matrix or their neighbouring cells. This cell death process has been termed "anoikis". Tumour cells that acquire malignant potential have developed mechanisms to resist anoikis and thereby survive after detachment from their primary site and while travelling through the lymphatic and circulatory systems. Defects in the death receptor pathway of caspase activation, such as the over-expression of the caspase-8 inhibitor FLIP, can render cells resistant to anoikis. Likewise, roadblocks in the mitochondrial pathway, such as over-expression of the Bcl-2 family of anti-apoptotic proteins, can also confer resistance to anoikis. This review will focus on the roles of the death receptor and mitochondrial pathways in anoikis and anoikis resistance and how targeting defects in these pathways can restore sensitivity to anoikis and serve as the basis for therapeutic adjuncts that prevent metastasis.
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Affiliation(s)
- Craig D Simpson
- Ontario Cancer Institute, Princess Margaret Hospital, University of Toronto, 610 University Avenue, Toronto, Ont., Canada M5G 2M9
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19
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Mawji IA, Simpson CD, Gronda M, Williams MA, Hurren R, Henderson CJ, Datti A, Wrana JL, Schimmer AD. A Chemical Screen Identifies Anisomycin as an Anoikis Sensitizer That Functions by Decreasing FLIP Protein Synthesis. Cancer Res 2007; 67:8307-15. [PMID: 17804746 DOI: 10.1158/0008-5472.can-07-1687] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Malignant epithelial cells with metastatic potential resist apoptosis that normally occurs upon loss of anchorage from the extracellular matrix, a process termed "anoikis." Resistance to anoikis enables malignant cells to survive in an anchorage-independent manner, which leads to the formation of distant metastases. To understand the regulation of anoikis, we designed, automated, and conducted a high-throughput chemical screen for anoikis sensitizers. PPC-1 anoikis-resistant prostate cancer cells were seeded in hydrogel-coated ultralow binding plates for suspension conditions and standard tissue culture plates to promote adhesion. After seeding, cells were treated with aliquots from a library of previously characterized small molecules, and viability was assessed using the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt, assay. From this chemical screen, we identified anisomycin that induced apoptosis in suspension conditions, but was not toxic to these cells grown under adherent conditions. Anisomycin sensitized cells to anoikis by decreasing levels of the caspase-8 inhibitor FLIP and subsequently activating the death receptor pathway of caspase activation. Although anisomycin activated c-Jun-NH(2)-kinase and p38, these kinases were not functionally important for the effect of anisomycin on anoikis and FLIP. Rather, anisomycin decreased FLIP and sensitized cells to anoikis by inhibiting its protein synthesis. Finally, we showed that anisomycin decreased distal tumor formation in a mouse model of prostate cancer metastases. Thus, a novel chemical screen identified anisomycin as an anoikis sensitizer that acts by decreasing FLIP protein synthesis. Our results suggest that FLIP is a suppressor of anoikis and inhibiting FLIP protein synthesis may be a useful antimetastatic strategy.
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Affiliation(s)
- Imtiaz A Mawji
- Ontario Cancer Institute, Princess Margaret Hospital, Mt Sinai Hospital, Toronto, Ontario, Canada
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20
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Mawji IA, Simpson CD, Hurren R, Gronda M, Williams MA, Filmus J, Jonkman J, Da Costa RS, Wilson BC, Thomas MP, Reed JC, Glinsky GV, Schimmer AD. Critical role for Fas-associated death domain-like interleukin-1-converting enzyme-like inhibitory protein in anoikis resistance and distant tumor formation. J Natl Cancer Inst 2007; 99:811-22. [PMID: 17505076 DOI: 10.1093/jnci/djk182] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [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: 11/12/2022] Open
Abstract
BACKGROUND Normal epithelial cells undergo anoikis, or apoptosis on loss of anchorage to the extracellular matrix, by initiating the death receptor pathway of caspase activation. However, malignant epithelial cells with metastatic potential resist anoikis and can survive in an anchorage-independent fashion. We hypothesized that c-Fas-associated death domain-like interleukin-1-converting enzyme-like inhibitory protein (FLIP), an endogenous inhibitor of death receptor signaling, may suppress anoikis. METHODS We assessed viability and apoptosis of PPC-1 prostate cancer cells cultured in adherent and suspension conditions using 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium inner salt and Annexin V staining assays. Expression of the death receptor Fas and activation of caspase 8 were measured using flow cytometry. Expression of Fas ligand was measured by reverse transcription-polymerase chain reaction. FLIP protein expression was measured by immunoblotting. Small-molecule inhibitors of FLIP (including the death receptor sensitizer 5809354) and small-interfering (si) RNA directed against FLIP were used to assess the effects of FLIP inhibition on anoikis of prostate cancer cells in vitro and in vivo. All statistical tests were two-sided. RESULTS PPC-1 cells cultured in suspension resisted anoikis, despite increased expression of Fas (0 versus 8 hours, mean relative percent expression = 100% versus 135%, difference = 35%, 95% confidence interval [CI] = 10% to 61%; P = .02) and Fas L (0 versus 24 hours, mean relative percent expression = 100% versus 208%, difference = 108%, 95% CI = 18% to 197%; P = .02). Knockdown of FLIP expression by siRNA or treatment with 5809354 sensitized prostate cancer cells to anoikis (control siRNA versus FLIP siRNA at 10 nM, mean relative percent viability = 95% versus 51%, difference = 44%, 95% CI = 34% to 54%; P<.001; control versus 5809354 at 20 microM, mean relative percent viability = 96% versus 52%, difference = 44%, 95% CI = 13% to 75%; P = .015). Inhibition of FLIP expression specifically activated caspase 8 in PPC-1 cells grown in suspension but not adherent conditions and decreased the metastatic potential of circulating PPC-1 cells in vivo. CONCLUSIONS FLIP may be a suppressor of anoikis and therefore a possible target for antimetastatic therapeutic strategies.
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Affiliation(s)
- Imtiaz A Mawji
- Ontario Cancer Institute, Princess Margaret Hospital, 610 University Ave, Toronto, ON, Canada, M5G 2M9
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21
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Leung-Toung R, Tam TF, Zhao Y, Simpson CD, Li W, Desilets D, Karimian K. Synthesis of 3-Substituted Bicyclic Imidazo[1,2-d][1,2,4]thiadiazoles and Tricyclic Benzo[4,5]imidazo[1,2-d][1,2,4]thiadiazoles. J Org Chem 2005; 70:6230-41. [PMID: 16050682 DOI: 10.1021/jo0507486] [Citation(s) in RCA: 27] [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: 11/29/2022]
Abstract
A versatile synthetic route to potentially useful fused-ring [1,2,4]thiadiazole scaffolds (e.g., 7a and 10b) via exchange reactions of the precursor [1,2,4]thiadiazol-3-(2H)one derivatives (e.g., 6 and 9) with appropriately substituted nitriles (e.g., cyanogen bromide or p-toluenesulfonyl cyanide) under mild conditions is described. For example, the tricyclic 3-bromo [1,2,4]THD derivative (7a) underwent S(N)Ar substitution with a variety of nucleophiles, which included amines, malonate esters and alcohols. Likewise, the bicyclic 3-p-tosyl [1,2,4]THD (10b) was employed as a template in reaction with diamines, and the resulting substituted diamines (e.g., 12a or 12e) were further selectively derivatized at the N1 and/or N2 positions in a linear fashion. The X-ray crystal structure of the 3-methyl bicyclic [1,2,4]THD (21) was obtained, and selective methylation at the N1 position via a protection-alkylation-deprotection protocol, as illustrated in Scheme 6, was confirmed. Alternatively, a short convergent synthesis of N1-functionalized derivatives from the reaction of 10b with appropriately substituted secondary amines was also developed. Hence, these synthetic strategies were advantageously exploited to provide access to a variety of diversely derivatized 3-substituted fused-ring [1,2,4]thiadiazole derivatives.
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Affiliation(s)
- Regis Leung-Toung
- Medicinal Chemistry Department, ApoPharma, Inc., 400 Ormont Drive, Toronto, ON M9L 1N9, Canada.
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22
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Leung-Toung R, Tam TF, Wodzinska JM, Zhao Y, Lowrie J, Simpson CD, Karimian K, Spino M. 3-Substituted imidazo[1,2-d][1,2,4]-thiadiazoles: a novel class of factor XIIIa inhibitors. J Med Chem 2005; 48:2266-9. [PMID: 15801818 DOI: 10.1021/jm049221w] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [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: 11/28/2022]
Abstract
A new class of selective FXIIIa inhibitors with a bicyclic [1,2,4]-thiadiazole pharmacophore is described. At 160 muM, compound 8 caused 50% reduction in fibrin gamma-chain cross-linking and suppressed the polymerization of alpha chains in platelet-depleted human plasma clots. Fibrinolysis rates in response to tissue plasminogen activator were directly proportional to the concentration of 8 in plasma at the time of clotting.
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Affiliation(s)
- Regis Leung-Toung
- Department of Medicinal Chemistry, Apotex Research Inc., 400 Ormont Drive, Toronto, ON M9L 1N9, Canada
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Simpson CD, Onyett H. Epidemiology of Invasive Pneumococcal and Meningococcal Disease in Southeastern Ontario: is Universal Infant Immunization Cost-Effective? Paediatr Child Health 2003. [DOI: 10.1093/pch/8.suppl_b.28bb] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Abstract
OBJECTIVE Data from electroencephalograms (EEGs), including data from visual evoked-potential studies, were analyzed to assess their association with a specific type of explosive behavior in children and adolescents. METHODS Data for 326 children and adolescents treated in a psychiatric clinic were examined. Eighty-two percent exhibited behavior consistent with intermittent explosive disorder, although diagnosis was not an inclusion criterion for the study. The presence of explosive behaviors was indicated by reports from the legal system, schools, parents, health care workers, and psychiatric intake interviews. A quantitative EEG and a series of pattern-reversal evoked-potential studies were administered to each patient. In these studies, children are shown a rapidly reversing checkerboard pattern or rapid flashes of light, and their brain waves (evoked potentials) are measured. RESULTS Logistic regression indicated that patients who exhibited explosive behaviors were significantly more likely to produce high-amplitude P100 wave forms in the evoked-potential studies than patients who did not exhibit explosive behaviors. Forty-six percent of those with explosive behaviors met the clinically defined electrophysiological criteria for the high-amplitude P100 wave forms. CONCLUSIONS The use of visual evoked-potential studies helped us classify a large subset of youths who exhibited out-of-control explosive behaviors. The findings suggest that a subgroup of individuals exhibiting explosive behaviors may have a predisposition for violent or explosive behavior that is an innate characteristic of their central nervous system. An understanding of the etiology of explosive behaviors permits the use of more appropriate intervention and treatment strategies.
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Affiliation(s)
- D R Bars
- Behavioral Management Centers, Boise, ID 83704, USA.
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25
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Simpson CD, Wu MT, Christiani DC, Santella RM, Carmella SG, Hecht SS. Determination of r-7,t-8,9,c-10-tetrahydroxy-7,8,9, 10-tetrahydrobenzo[a]pyrene in human urine by gas chromatography/negative ion chemical ionization/mass spectrometry. Chem Res Toxicol 2000; 13:271-80. [PMID: 10775327 DOI: 10.1021/tx990202c] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [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: 11/28/2022]
Abstract
r-7,t-8,9,c-10-Tetrahydroxy-7,8,9,10-tetrahydrobenzo[a]pyrene (trans-anti-BaP-tetraol) is the major hydrolysis product of r-7, t-8-dihydroxy-t-9,10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (anti-BPDE), the principal ultimate carcinogen of the environmental pollutant benzo[a]pyrene (BaP). As part of a program to establish activation/detoxification profiles of urinary metabolites of BaP in humans, we developed a method for quantifying trans-anti-BaP-tetraol. Urine was collected from three groups of individuals exposed to BaP: psoriasis patients treated with a coal tar-containing ointment, steel workers, and smokers. [(2)H(12)]-trans-anti-BaP-tetraol was added to the urine as an internal standard. The urine was treated with beta-glucuronidase and sulfatase, and then the BaP-tetraols were enriched by reverse-phase and phenylboronic acid solid-phase extraction. The resulting fraction was treated with sodium hydride and methylmethane sulfonate to convert BaP-tetraols to the corresponding tetramethyl ethers (BaP-TME). The mixture was purified by normal-phase HPLC and analyzed by gas chromatography/negative ion chemical ionization/mass spectrometry with selected ion monitoring. [(13)CH(3)](4)-trans-anti-BaP-TME was used as an external standard. Ions at m/z 376, 380, and 388 were monitored for quantitation of trans-anti-BaP-TME, [(13)CH(3)](4)-trans-anti-BaP-TME, and [(2)H(12)]-trans-anti-BaP-TME, respectively. The instrumental detection limit was approximately 1 fmol of trans-anti-BaP-TME. trans-anti-BaP-tetraol (as trans-anti-BaP-TME) was detected in 20 of 20 individuals receiving coal tar therapy (mean, 16 fmol/mL of urine), 13 of 13 exposed steel workers (mean, 4.1 fmol/mL of urine), and nine of 21 cigarette smokers (mean, 0.5 fmol/mL of urine). The means in these groups were significantly different (P < 0.0001). The urine of steel workers was also analyzed for cis-anti-BaP-tetraol and cys-syn-BaP-tetraol, but neither was found. The results of this study provide a quantitative method for determination of parts per trillion levels of trans-anti-BaP-tetraol in human urine. Ultimately, this method can be employed as part of a phenotyping approach for assessing BaP metabolites in human urine.
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Affiliation(s)
- C D Simpson
- University of Minnesota Cancer Center, Minneapolis 55455, USA
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26
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De Logu A, Williamson RA, Rozenshteyn R, Ramiro-Ibañez F, Simpson CD, Burton DR, Sanna PP. Characterization of a type-common human recombinant monoclonal antibody to herpes simplex virus with high therapeutic potential. J Clin Microbiol 1998; 36:3198-204. [PMID: 9774565 PMCID: PMC105301 DOI: 10.1128/jcm.36.11.3198-3204.1998] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We report the characterization of a type-common human recombinant monoclonal antibody previously isolated by antigen selection from a phage-displayed combinatorial antibody library established from a herpes simplex virus (HSV)-seropositive individual. Competition with well-characterized murine monoclonal antibodies and immunodetection of gD truncations revealed that this antibody recognizes the group Ib antigenic site of glycoprotein D, a highly conserved and protective type-common determinant. To our knowledge, this is the first human group Ib monoclonal antibody ever described. The antibody also displayed first-order neutralization kinetics and a high neutralization rate constant, was capable of completely inhibiting syncytium formation by a fusogenic strain of HSV type 1, and efficiently neutralized low-passage clinical isolates of both HSV serotypes. Taken together with our earlier observations of the in vivo antiviral activities of this human recombinant antibody in animal models of HSV infection, the present results support the high therapeutic potential of this antibody.
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MESH Headings
- Animals
- Antibodies, Monoclonal/classification
- Antibodies, Monoclonal/genetics
- Antibodies, Monoclonal/therapeutic use
- Antibodies, Viral/genetics
- Antibodies, Viral/metabolism
- Antibodies, Viral/therapeutic use
- Antigens, Viral/genetics
- Chlorocebus aethiops
- Cytopathogenic Effect, Viral/immunology
- Epitope Mapping
- Herpes Simplex/therapy
- Herpesvirus 1, Human/genetics
- Herpesvirus 1, Human/immunology
- Herpesvirus 2, Human/genetics
- Herpesvirus 2, Human/immunology
- Humans
- Immunization, Passive
- In Vitro Techniques
- Kinetics
- Mice
- Neutralization Tests
- Recombinant Proteins/genetics
- Recombinant Proteins/immunology
- Recombinant Proteins/therapeutic use
- Simplexvirus/immunology
- Vero Cells
- Viral Envelope Proteins/genetics
- Viral Envelope Proteins/immunology
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Affiliation(s)
- A De Logu
- Departments of Neuropharmacology, The Scripps Research Institute, La Jolla, California, USA
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Abstract
Inflammatory bowel disease is rarely associated with pericarditis but both sulfasalazine and the aminosalicylates have been known to cause this complication. To the author's knowledge this is the first reported case of acute pericarditis caused by azathioprine. It is believed that pericarditis is yet another potential manifestation of hypersensitivity to this drug.
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Affiliation(s)
- C D Simpson
- Department of Medicine, Queen Elizabeth II Health Sciences Centre, Dalhousie University, Halifax, Nova Scotia
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Simpson CD, Mosi AA, Cullen WR, Reimer KJ. Composition and distribution of polycyclic aromatic hydrocarbon contamination in surficial marine sediments from Kitimat Harbor, Canada. Sci Total Environ 1996; 181:265-278. [PMID: 8820441 DOI: 10.1016/0048-9697(95)05026-4] [Citation(s) in RCA: 40] [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] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Surficial marine sediments from 20 sites within the Kitimat fjord system were analyzed for polycylic aromatic hydrocarbons (PAHs). Levels of the sum of the 16 USEPA priority pollutant PAHs varied from below detection limits (ca. 1 microg x g-1) to over 10 000 microg x g-1. Sediment PAH levels were highest in the immediate vicinity of a large aluminum smelter at the head of Kitimat Arm, and declined rapidly with increasing distance from the smelter. However, even at some of the more distant sites which are geographically isolated from the smelter PAH levels were elevated. The PAH distribution in the fjord system is consistent with a combination of aeolian and fluvial transport of PAHs emitted by the aluminum smelter at the head of Kitimat Arm. The mixture of PAHs present was qualitatively similar in all samples analyzed, including those from the distant sites. All aspects of the PAH composition are consistent with combustion generated PAHs. A correlation between PAH levels and sediment organic carbon was observed; however, this was only significant for highly contaminated sites in the harbor. This probably reflects the high organic content of particulate emissions from the smelter, rather than equilibrium partitioning of PAHs to sediment organic carbon within the harbor itself.
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Affiliation(s)
- C D Simpson
- Chemistry Department, University of British Columbia, Vancouver, BC, Canada
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Simpson CD, Smith TJ, Burggraaf S, Wilkins AL, Langdon AG, Wilcock RJ. Identification of a point source of chlordane contamination from a timber treatment facility. Bull Environ Contam Toxicol 1995; 55:289-295. [PMID: 7579937 DOI: 10.1007/bf00203023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Affiliation(s)
- C D Simpson
- Chemistry Department, University of British Columbia, Vancouver, Canada
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Simpson CD, Wilcock RJ, Smith TJ, Wilkins AL, Langdon AG. Determination of octanol-water partition coefficients for the major components of technical chlordane. Bull Environ Contam Toxicol 1995; 55:149-153. [PMID: 7663085 DOI: 10.1007/bf00212402] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Affiliation(s)
- C D Simpson
- Chemistry Department, University of British Columbia, Vancouver, Canada
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Simpson CD, Aitken SE. Malignant histiocytosis associated with SIADH and retinal hemorrhages. Can Med Assoc J 1982; 127:302-3. [PMID: 6178492 PMCID: PMC1861884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Brittin HC, Armes CL, Ramsey CB, Simpson CD. Consumer acceptability of ground venison. J Am Diet Assoc 1982; 80:557-560. [PMID: 7086008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The acceptability of ground venison was evaluated by 91 consumers. Four meat patties were formulated: 100 percent beef, 100 venison, 50 percent venison/50 percent beef, and 50 percent venison/50 percent pork. The four patties received similar acceptability scores, except that the all-venison patty was less juicy and had a stronger game flavor. Mixing venison with beef or pork in a patty with about 18 percent fat increased the juiciness and decreased the game flavor. Mixing ground venison with ground beef or pork could make venison more palatable to consumers.
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Abstract
Sera were collected from 12 Barbary sheet (Ammotragus lervia) and 11 mule deer (Odocoileus hemionus) occupying sympatric ranges in Palo Duro Canyon, Texas. These were tested for leptospirosis, brucellosis, bovine virus diarrhea, anaplasmosis, vesicular stomatitis, bluetongue (BT), epizootic hemorrhagic disease (EHD), infectious bovine rhinotracheitis (IBR), and coccidioidomycosis. Serologic reactors were found to IBR in 3 Barbery sheep, BT in 6 Barbary sheep and 6 mule deer and EHD in 3 Barbary sheep and 4 mule deer. Possible ramifications of evidence for these diseases in wild herbivore populations in this area are discussed.
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Simpson CD. Comparative mammalian mastication. Angle Orthod 1978; 48:93-105. [PMID: 277081 DOI: 10.1043/0003-3219(1978)048<0093:cmm>2.0.co;2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
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Abstract
A battery of psychological tests was administered to 26 medical students in a counterbalanced cross-over design to determine the effects of an acute dose of alcohol on perceptual, perceptual-motor and cognitive capacities. The tests included: temporal acuity (critical flicker fusion threshold), perceptual speed and attention (Stroop), perceptual-motor coordination (Purdue Pegboard), perceptual-motor speed (simple and choice reaction time), immediate memory (WAIS Digit Span), short-term memory (dichotic stimulation), and intellectual and conceptual capacity (Shipley Institute of Living Scale). Three general conclusions were drawn: (1) alcohol exerted a deteriorating effect on performance on all tasks except the Stroop, (2) retesting 48 hr. later showed that practice or familiarity with the task mitigated the effects of the alcohol, and (3) contrary to the hypothesis advanced by Jellineck and McFarland (1940), no systematic relationship was observed between task complexity and degree of impairment from the alcohol.
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Simpson CD. Experimental mandibular dysplasia. Angle Orthod 1966; 36:224-35. [PMID: 5221254 DOI: 10.1043/0003-3219(1966)036<0224:emd>2.0.co;2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
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