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Abstract
Lymphangioleiomyomatosis (LAM) is a rare, low-grade, metastasizing neoplasm that arises from an unknown source, spreads via the lymphatics, and targets the lungs. All pulmonary structures become infiltrated with benign-appearing spindle and epithelioid cells (LAM cells) that express smooth-muscle and melanocyte-lineage markers, harbor mTOR-activating mutations in tuberous sclerosis complex (TSC) genes, and recruit abundant stromal cells. Elaboration of lymphangiogenic growth factors and matrix remodeling enzymes by LAM cells enables their access to lymphatic channels and likely drives the cystic lung remodeling that often culminates in respiratory failure. Dysregulated cellular signaling results in a shift from oxidative phosphorylation to glycolysis as the preferred mode of energy generation, to allow for the accumulation of biomass required for cell growth and tolerance of nutrient-poor, anaerobic environments. Symptomatic LAM occurs almost exclusively in females after menarche, highlighting the central but as yet poorly understood role for sex-restricted anatomical structures and/or hormones in disease pathogenesis. LAM is an elegant model of malignancy because biallelic mutations at a single genetic locus confer all features that define cancer upon the LAM cell-metabolic reprogramming and proliferative signals that drive uncontrolled growth and inappropriate migration and invasion, the capacity to exploit the lymphatic circulation as a vehicle for metastasis and access to the lungs, and destruction of remote tissues. The direct benefit of the study of this rare disease has been the rapid identification of an effective FDA-approved therapy, and the collateral benefits have included elucidation of the pivotal roles of mTOR signaling in the regulation of cellular metabolism and the pathogenesis of cancer.
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Affiliation(s)
- Vera P Krymskaya
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Francis X McCormack
- Department of Internal Medicine, University of Cincinnati School of Medicine, Cincinnati, Ohio 45267;
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252
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Faes S, Planche A, Uldry E, Santoro T, Pythoud C, Stehle JC, Horlbeck J, Letovanec I, Riggi N, Datta D, Demartines N, Dormond O. Targeting carbonic anhydrase IX improves the anti-cancer efficacy of mTOR inhibitors. Oncotarget 2017; 7:36666-36680. [PMID: 27153561 PMCID: PMC5095030 DOI: 10.18632/oncotarget.9134] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2015] [Accepted: 04/18/2016] [Indexed: 12/14/2022] Open
Abstract
The inhibition of the mechanistic target of rapamycin complex 1 (mTORC1) by chemical inhibitors, such as rapamycin, has demonstrated anti-cancer activity in preclinical and clinical trials. Their efficacy is, however, limited and tumors eventually relapse through resistance formation. In this study, using two different cancer mouse models, we identify tumor hypoxia as a novel mechanism of resistance of cancer cells against mTORC1 inhibitors. Indeed, we show that the activity of mTORC1 is mainly restricted to the non-hypoxic tumor compartment, as evidenced by a mutually exclusive staining pattern of the mTORC1 activity marker pS6 and the hypoxia marker pimonidazole. Consequently, whereas rapamycin reduces cancer cell proliferation in non-hypoxic regions, it has no effect in hypoxic areas, suggesting that cancer cells proliferate independently of mTORC1 under hypoxia. Targeting the hypoxic tumor compartment by knockdown of carbonic anhydrase IX (CAIX) using short hairpin RNA or by chemical inhibition of CAIX with acetazolamide potentiates the anti-cancer activity of rapamycin. Taken together, these data emphasize that hypoxia impairs the anti-cancer efficacy of rapalogs. Therapeutic strategies targeting the hypoxic tumor compartment, such as the inhibition of CAIX, potentiate the efficacy of rapamycin and warrant further clinical evaluation.
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Affiliation(s)
- Seraina Faes
- Department of Visceral Surgery, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Anne Planche
- Department of Visceral Surgery, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Emilie Uldry
- Department of Visceral Surgery, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Tania Santoro
- Department of Visceral Surgery, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Catherine Pythoud
- Department of Visceral Surgery, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Jean-Christophe Stehle
- Mouse Pathology Facility, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Janine Horlbeck
- Mouse Pathology Facility, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Igor Letovanec
- Institute of Pathology, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Nicolo Riggi
- Institute of Pathology, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Dipak Datta
- Biochemistry Division, CSIR-Central Drug Research Institute, Lucknow, India.,Academy of Scientific and Innovative Research, New Delhi, India
| | - Nicolas Demartines
- Department of Visceral Surgery, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Olivier Dormond
- Department of Visceral Surgery, University Hospital and University of Lausanne, Lausanne, Switzerland
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253
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Eukaryotic Elongation Factor 2 Kinase (eEF2K) in Cancer. Cancers (Basel) 2017; 9:cancers9120162. [PMID: 29186827 PMCID: PMC5742810 DOI: 10.3390/cancers9120162] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 11/24/2017] [Accepted: 11/25/2017] [Indexed: 12/31/2022] Open
Abstract
Eukaryotic elongation factor 2 kinase (eEF2K) is a highly unusual protein kinase that negatively regulates the elongation step of protein synthesis. This step uses the vast majority of the large amount of energy and amino acids required for protein synthesis. eEF2K activity is controlled by an array of regulatory inputs, including inhibition by signalling through mammalian target of rapamycin complex 1 (mTORC1). eEF2K is activated under conditions of stress, such as energy depletion or nutrient deprivation, which can arise in poorly-vascularised tumours. In many such stress conditions, eEF2K exerts cytoprotective effects. A growing body of data indicates eEF2K aids the growth of solid tumours in vivo. Since eEF2K is not essential (in mice) under ‘normal’ conditions, eEF2K may be a useful target in the treatment of solid tumours. However, some reports suggest that eEF2K may actually impair tumorigenesis in some situations. Such a dual role of eEF2K in cancer would be analogous to the situation for other pathways involved in cell metabolism, such as autophagy and mTORC1. Further studies are needed to define the role of eEF2K in different tumour types and at differing stages in tumorigenesis, and to assess its utility as a therapeutic target in oncology.
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254
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Rebecca VW, Nicastri MC, McLaughlin N, Fennelly C, McAfee Q, Ronghe A, Nofal M, Lim CY, Witze E, Chude CI, Zhang G, Alicea GM, Piao S, Murugan S, Ojha R, Levi SM, Wei Z, Barber-Rotenberg JS, Murphy ME, Mills GB, Lu Y, Rabinowitz J, Marmorstein R, Liu Q, Liu S, Xu X, Herlyn M, Zoncu R, Brady DC, Speicher DW, Winkler JD, Amaravadi RK. A Unified Approach to Targeting the Lysosome's Degradative and Growth Signaling Roles. Cancer Discov 2017; 7:1266-1283. [PMID: 28899863 PMCID: PMC5833978 DOI: 10.1158/2159-8290.cd-17-0741] [Citation(s) in RCA: 131] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 08/24/2017] [Accepted: 09/06/2017] [Indexed: 01/01/2023]
Abstract
Lysosomes serve dual roles in cancer metabolism, executing catabolic programs (i.e., autophagy and macropinocytosis) while promoting mTORC1-dependent anabolism. Antimalarial compounds such as chloroquine or quinacrine have been used as lysosomal inhibitors, but fail to inhibit mTOR signaling. Further, the molecular target of these agents has not been identified. We report a screen of novel dimeric antimalarials that identifies dimeric quinacrines (DQ) as potent anticancer compounds, which concurrently inhibit mTOR and autophagy. Central nitrogen methylation of the DQ linker enhances lysosomal localization and potency. An in situ photoaffinity pulldown identified palmitoyl-protein thioesterase 1 (PPT1) as the molecular target of DQ661. PPT1 inhibition concurrently impairs mTOR and lysosomal catabolism through the rapid accumulation of palmitoylated proteins. DQ661 inhibits the in vivo tumor growth of melanoma, pancreatic cancer, and colorectal cancer mouse models and can be safely combined with chemotherapy. Thus, lysosome-directed PPT1 inhibitors represent a new approach to concurrently targeting mTORC1 and lysosomal catabolism in cancer.Significance: This study identifies chemical features of dimeric compounds that increase their lysosomal specificity, and a new molecular target for these compounds, reclassifying these compounds as targeted therapies. Targeting PPT1 blocks mTOR signaling in a manner distinct from catalytic inhibitors, while concurrently inhibiting autophagy, thereby providing a new strategy for cancer therapy. Cancer Discov; 7(11); 1266-83. ©2017 AACR.See related commentary by Towers and Thorburn, p. 1218This article is highlighted in the In This Issue feature, p. 1201.
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Affiliation(s)
- Vito W Rebecca
- Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Michael C Nicastri
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Noel McLaughlin
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Colin Fennelly
- Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Quentin McAfee
- Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Amruta Ronghe
- Molecular and Cellular Oncogenesis Program and Melanoma Research Center, Wistar Institute, Philadelphia, Pennsylvania
| | - Michel Nofal
- Department of Chemistry and Integrative Genomics, Princeton University, Princeton, New Jersey
| | - Chun-Yan Lim
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California
| | - Eric Witze
- Department of Cancer Biology, Abramson Family Cancer Research Institute, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Cynthia I Chude
- Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Gao Zhang
- Molecular and Cellular Oncogenesis Program and Melanoma Research Center, Wistar Institute, Philadelphia, Pennsylvania
| | - Gretchen M Alicea
- Molecular and Cellular Oncogenesis Program and Melanoma Research Center, Wistar Institute, Philadelphia, Pennsylvania
| | - Shengfu Piao
- Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | | | - Rani Ojha
- Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Samuel M Levi
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Zhi Wei
- Department of Computer Science, New Jersey Institute of Technology, Newark, New Jersey
| | - Julie S Barber-Rotenberg
- Department of Biochemistry and Biophysics, Abramson Family Cancer Research Institute, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Maureen E Murphy
- Molecular and Cellular Oncogenesis Program and Melanoma Research Center, Wistar Institute, Philadelphia, Pennsylvania
| | - Gordon B Mills
- Department of Systems Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Yiling Lu
- Department of Systems Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Joshua Rabinowitz
- Department of Chemistry and Integrative Genomics, Princeton University, Princeton, New Jersey
| | - Ronen Marmorstein
- Department of Biochemistry and Biophysics, Abramson Family Cancer Research Institute, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Qin Liu
- Molecular and Cellular Oncogenesis Program and Melanoma Research Center, Wistar Institute, Philadelphia, Pennsylvania
| | - Shujing Liu
- Department of Pathology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Xiaowei Xu
- Department of Pathology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Meenhard Herlyn
- Molecular and Cellular Oncogenesis Program and Melanoma Research Center, Wistar Institute, Philadelphia, Pennsylvania
| | - Roberto Zoncu
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California
| | - Donita C Brady
- Department of Cancer Biology, Abramson Family Cancer Research Institute, University of Pennsylvania, Philadelphia, Pennsylvania
| | - David W Speicher
- Molecular and Cellular Oncogenesis Program and Melanoma Research Center, Wistar Institute, Philadelphia, Pennsylvania
| | - Jeffrey D Winkler
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania.
- Abramson Cancer Center, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Ravi K Amaravadi
- Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
- Abramson Cancer Center, University of Pennsylvania, Philadelphia, Pennsylvania
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255
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Wyant GA, Abu-Remaileh M, Wolfson RL, Chen WW, Freinkman E, Danai LV, Vander Heiden MG, Sabatini DM. mTORC1 Activator SLC38A9 Is Required to Efflux Essential Amino Acids from Lysosomes and Use Protein as a Nutrient. Cell 2017; 171:642-654.e12. [PMID: 29053970 DOI: 10.1016/j.cell.2017.09.046] [Citation(s) in RCA: 300] [Impact Index Per Article: 42.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 07/18/2017] [Accepted: 09/25/2017] [Indexed: 12/17/2022]
Abstract
The mTORC1 kinase is a master growth regulator that senses many environmental cues, including amino acids. Activation of mTORC1 by arginine requires SLC38A9, a poorly understood lysosomal membrane protein with homology to amino acid transporters. Here, we validate that SLC38A9 is an arginine sensor for the mTORC1 pathway, and we uncover an unexpectedly central role for SLC38A9 in amino acid homeostasis. SLC38A9 mediates the transport, in an arginine-regulated fashion, of many essential amino acids out of lysosomes, including leucine, which mTORC1 senses through the cytosolic Sestrin proteins. SLC38A9 is necessary for leucine generated via lysosomal proteolysis to exit lysosomes and activate mTORC1. Pancreatic cancer cells, which use macropinocytosed protein as a nutrient source, require SLC38A9 to form tumors. Thus, through SLC38A9, arginine serves as a lysosomal messenger that couples mTORC1 activation to the release from lysosomes of the essential amino acids needed to drive cell growth.
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Affiliation(s)
- Gregory A Wyant
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, 9 Cambridge Center, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Cambridge, MA 02139, USA; Koch Institute for Integrative Cancer Research, 77 Massachusetts Avenue, Cambridge, MA 02139, USA; Broad Institute of MIT and Harvard, 7 Cambridge Center, Cambridge, MA 02142, USA
| | - Monther Abu-Remaileh
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, 9 Cambridge Center, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Cambridge, MA 02139, USA; Koch Institute for Integrative Cancer Research, 77 Massachusetts Avenue, Cambridge, MA 02139, USA; Broad Institute of MIT and Harvard, 7 Cambridge Center, Cambridge, MA 02142, USA
| | - Rachel L Wolfson
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, 9 Cambridge Center, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Cambridge, MA 02139, USA; Koch Institute for Integrative Cancer Research, 77 Massachusetts Avenue, Cambridge, MA 02139, USA; Broad Institute of MIT and Harvard, 7 Cambridge Center, Cambridge, MA 02142, USA; Harvard Medical School M.D.-Ph.D. Program, Daniel C. Tosteson Medical Education Center, 260 Longwood Avenue, Boston, MA 02115, USA
| | - Walter W Chen
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, 9 Cambridge Center, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Cambridge, MA 02139, USA; Koch Institute for Integrative Cancer Research, 77 Massachusetts Avenue, Cambridge, MA 02139, USA; Broad Institute of MIT and Harvard, 7 Cambridge Center, Cambridge, MA 02142, USA; Harvard Medical School M.D.-Ph.D. Program, Daniel C. Tosteson Medical Education Center, 260 Longwood Avenue, Boston, MA 02115, USA
| | - Elizaveta Freinkman
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, 9 Cambridge Center, Cambridge, MA 02142, USA
| | - Laura V Danai
- Koch Institute for Integrative Cancer Research, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
| | - Matthew G Vander Heiden
- Koch Institute for Integrative Cancer Research, 77 Massachusetts Avenue, Cambridge, MA 02139, USA; Broad Institute of MIT and Harvard, 7 Cambridge Center, Cambridge, MA 02142, USA; Dana-Farber Cancer Institute, Boston, MA 02115, USA
| | - David M Sabatini
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, 9 Cambridge Center, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Cambridge, MA 02139, USA; Koch Institute for Integrative Cancer Research, 77 Massachusetts Avenue, Cambridge, MA 02139, USA; Broad Institute of MIT and Harvard, 7 Cambridge Center, Cambridge, MA 02142, USA.
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256
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Palm W, Thompson CB. Nutrient acquisition strategies of mammalian cells. Nature 2017; 546:234-242. [PMID: 28593971 DOI: 10.1038/nature22379] [Citation(s) in RCA: 259] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 04/21/2017] [Indexed: 12/14/2022]
Abstract
Mammalian cells are surrounded by diverse nutrients, such as glucose, amino acids, various macromolecules and micronutrients, which they can import through transmembrane transporters and endolysosomal pathways. By using different nutrient sources, cells gain metabolic flexibility to survive periods of starvation. Quiescent cells take up sufficient nutrients to sustain homeostasis. However, proliferating cells depend on growth-factor-induced increases in nutrient uptake to support biomass formation. Here, we review cellular nutrient acquisition strategies and their regulation by growth factors and cell-intrinsic nutrient sensors. We also discuss how oncogenes and tumour suppressors promote nutrient uptake and thereby support the survival and growth of cancer cells.
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Affiliation(s)
- Wilhelm Palm
- Cancer Biology and Genetics Program, Memorial Sloan Kettering Cancer Center, New York, New York 10065, USA
| | - Craig B Thompson
- Cancer Biology and Genetics Program, Memorial Sloan Kettering Cancer Center, New York, New York 10065, USA
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257
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Cameron AJ, Veeriah S, Marshall JJ, Murray ER, Larijani B, Parker PJ. Uncoupling TORC2 from AGC kinases inhibits tumour growth. Oncotarget 2017; 8:84685-84696. [PMID: 29156676 PMCID: PMC5689566 DOI: 10.18632/oncotarget.20086] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Accepted: 06/26/2017] [Indexed: 12/28/2022] Open
Abstract
Mammalian target of rapamycin (mTOR) is a central regulator of growth and metabolism. mTOR resides in two distinct multi-protein complexes - mTORC1 and mTORC2 - with distinct upstream regulators and downstream targets. While it is possible to specifically inhibit mTORC1 with rapamycin, or inhibit both mTOR complexes together with ATP pocket directed mTOR kinase inhibitors, it is not possible to assess the specific roles for mTORC2 pharmacologically. To overcome this, we have developed a novel, inducible, dominant negative system for disrupting substrate recruitment to mTORC2. Previously we identified the mTORC2 specific subunit Sin1 as a direct binding partner for AGC kinases Akt and PKC. Sin1 mutants, which retain the ability to bind Rictor and mTOR, but fail to recruit their AGC client kinases, inhibit AKT and PKC priming and block cell growth. In this study, we demonstrate that uncoupling mTORC2 from AGC kinases in DLD1 colon cancer cells inhibits Akt activation and blocks tumour growth in vivo. Further we demonstrate, using time resolved two-site amplified FRET (A-FRET) analysis of xenograft tumours, that inhibition of tumour growth correlates with the degree of mTORC2 uncoupling from its downstream targets, as demonstrated for Akt. These data add weight to the body of evidence that mTORC2 represents a pharmacological target in cancer independently of mTORC1.
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Affiliation(s)
- Angus J.M. Cameron
- Kinase Biology Laboratory, Barts Cancer Institute, Queen Mary University of London, John Vane Science Centre, Charterhouse Square, London, UK
| | - Selvaraju Veeriah
- Translational Cancer Therapeutics Laboratory, Paul O’Gorman Building, University College London Cancer Institute, London, United Kingdom
- Protein Phosphorylation Laboratory, Francis Crick Institute, London, UK
| | | | - Elizabeth R. Murray
- Kinase Biology Laboratory, Barts Cancer Institute, Queen Mary University of London, John Vane Science Centre, Charterhouse Square, London, UK
| | - Banafshé Larijani
- Cell Biophysics Laboratory, Ikerbasque Basque Foundation for Science, Research Centre for Experimental Marine Biology and Biotechnology (PiE) & Biofísika Instituto (UPV/EHU, CSIC), University of the Basque Country, Areatza Hiribidea, Plentzia, Spain
| | - Peter J. Parker
- Protein Phosphorylation Laboratory, Francis Crick Institute, London, UK
- Division of Cancer Studies, King’s College London, New Hunts House, Guy’s Campus, London, UK
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258
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Critical role for PI3-kinase in regulating the use of proteins as an amino acid source. Proc Natl Acad Sci U S A 2017; 114:E8628-E8636. [PMID: 28973876 DOI: 10.1073/pnas.1712726114] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Ras-transformed cells can grow in amino acid-poor environments by recovering amino acids through macropinocytosis and lysosomal catabolism of extracellular proteins. However, when studying nontransformed fibroblasts, we found that Ras GTPases are dispensable for growth-factor-stimulated macropinocytosis and lysosomal catabolism of extracellular proteins. Instead, we establish a critical role for phosphatidylinositol 3-kinase (PI3-kinase) signaling in cell proliferation that is supported by protein macropinocytosis. Downstream of PI3-kinase, distinct effectors have opposing roles in regulating uptake and catabolism of extracellular proteins. Rac1 and PLC are required for nutritional use of extracellular proteins. In contrast, Akt suppresses lysosomal catabolism of ingested proteins when free amino acids are abundant. The interplay between these pathways allows cells with oncogenic PIK3CA mutations or PTEN deletion to grow using diverse amino acid sources. Thus, the prevalence of PI3-kinase and PTEN mutations in cancer may result in part because they allow cells to cope with fluctuating nutrient availability.
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259
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Abstract
The evolution of a nervous system as a control system of the body's functions is a key innovation of animals. Its fundamental units are neurons, highly specialized cells dedicated to fast cell-cell communication. Neurons pass signals to other neurons, muscle cells, or gland cells at specialized junctions, the synapses, where transmitters are released from vesicles in a Ca2+-dependent fashion to activate receptors in the membrane of the target cell. Reconstructing the origins of neuronal communication out of a more simple process remains a central challenge in biology. Recent genomic comparisons have revealed that all animals, including the nerveless poriferans and placozoans, share a basic set of genes for neuronal communication. This suggests that the first animal, the Urmetazoan, was already endowed with neurosecretory cells that probably started to connect into neuronal networks soon afterward. Here, we discuss scenarios for this pivotal transition in animal evolution.
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Affiliation(s)
- Frederique Varoqueaux
- Département des Neurosciences Fondamentales, Université de Lausanne, Lausanne, CH-1005 Switzerland; ,
| | - Dirk Fasshauer
- Département des Neurosciences Fondamentales, Université de Lausanne, Lausanne, CH-1005 Switzerland; ,
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260
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Swindell WR. Meta-Analysis of 29 Experiments Evaluating the Effects of Rapamycin on Life Span in the Laboratory Mouse. J Gerontol A Biol Sci Med Sci 2017; 72:1024-1032. [PMID: 27519886 DOI: 10.1093/gerona/glw153] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 07/12/2016] [Indexed: 12/16/2022] Open
Abstract
Rapamycin has favorable effects on aging in mice and may eventually be applied to encourage "healthy aging" in humans. This study analyzed raw data from 29 survival studies of rapamycin- and control-treated mice, with the goals of estimating summary statistics and identifying factors associated with effect size heterogeneity. Meta-analysis demonstrated significant heterogeneity across studies, with hazard ratio (HR) estimates ranging from 0.22 (95% confidence interval [CI]: 0.06-0.82) to 0.92 (95% CI: 0.65-1.28). Sex was the major factor accounting for effect size variation, and mortality was decreased more in females (HR = 0.41; 95% CI: 0.35-0.48) as compared with males (HR = 0.63; 95% CI: 0.55-0.71). Rapamycin effects were also genotype dependent, however, with stronger survivorship increases in hybrid mice (14.4%; 95% CI: 12.5-16.3%) relative to pure inbred strains (8.8%; 95% CI: 6.2-11.6%). Number needed to treat was applied as an effect size metric, which consistently identified early senescence as the age of peak treatment benefit. These results provide synthesis of existing data to support the potential translation of findings from mouse to primate species. Because rapamycin's effect on survival depends on sex and genotype, further work is justified to understand how these factors shape treatment response.
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261
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mTOR Inhibition Restores Amino Acid Balance in Cells Dependent on Catabolism of Extracellular Protein. Mol Cell 2017; 67:936-946.e5. [PMID: 28918901 DOI: 10.1016/j.molcel.2017.08.011] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 06/21/2017] [Accepted: 08/18/2017] [Indexed: 12/20/2022]
Abstract
Scavenging of extracellular protein via macropinocytosis is an alternative to monomeric amino acid uptake. In pancreatic cancer, macropinocytosis is driven by oncogenic Ras signaling and contributes substantially to amino acid supply. While Ras signaling promotes scavenging, mTOR signaling suppresses it. Here, we present an integrated experimental-computational method that enables quantitative comparison of protein scavenging rates across cell lines and conditions. Using it, we find that, independently of mTORC1, amino acid scarcity induces protein scavenging and that under such conditions the impact of mTOR signaling on protein scavenging rate is minimal. Nevertheless, mTOR inhibition promotes growth of cells reliant on eating extracellular protein. This growth enhancement depends on mTORC1's canonical function in controlling translation rate: mTOR inhibition slows translation, thereby matching protein synthesis to the limited amino acid supply. Thus, paradoxically, in amino acid-poor conditions the pro-anabolic effects of mTORC1 are functionally opposed to growth.
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262
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Teske C, Schweitzer C, Palamidessi A, Aust DE, Scita G, Weitz J, Welsch T. Modulation of RAB5A early endosome trafficking in response to KRas mediated macropinocytic fluxes in pancreatic cancer cells. Biochem Biophys Res Commun 2017; 493:528-533. [PMID: 28867190 DOI: 10.1016/j.bbrc.2017.08.157] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Accepted: 08/31/2017] [Indexed: 12/26/2022]
Abstract
KRAS is the key mutated gene in pancreatic ductal adenocarcinoma (PDAC). Emerging evidence indicates that KRas modulates endocytic uptake. The present study aimed to explore the fate of early endosomal trafficking under the control of KRas expression in PDAC. Surprisingly, PANC-1 cells lacking KRas exhibited significantly enlarged early and late endosomes containing internalized dextran and epidermal growth factor. Endosome enlargement was accompanied by reduced endosomal degradation. Both KRas silencing and lysosomal blockade caused an upregulation of the master regulator of early endosome biogenesis, RAB5A, which is likely responsible for the expansion of the early endosomal compartment, because simultaneous KRAS/RAB5A knockdown abolished endosome enlargement. In contrast, early endosome shrinkage was seen in MIA PaCa-2 cells despite RAB5A upregulation, indicating that distinct KRas-modulated responses operate in different metabolic subtypes of PDAC. In conclusion, mutant KRAS promotes endosomal degradation in PDAC cell lines, which is impaired by KRAS silencing. Moreover, KRAS silencing activates RAB5A upregulation and drives PDAC subtype-dependent modulation of endosome trafficking.
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Affiliation(s)
- Christian Teske
- Department of Visceral, Thoracic and Vascular Surgery, University Hospital Carl Gustav Carus, Technische Universität Dresden, Germany
| | - Christine Schweitzer
- Department of Visceral, Thoracic and Vascular Surgery, University Hospital Carl Gustav Carus, Technische Universität Dresden, Germany
| | - Andrea Palamidessi
- Fondazione Istituto FIRC di Oncologia Molecolare (IFOM), Via Adamello 16, 20139, Milan, Italy; Department of Hemato-Oncology (DIPO), University of Milan, Italy
| | - Daniela E Aust
- Institute for Pathology, University Hospital Carl Gustav Carus, Technische Universität Dresden, Germany
| | - Giorgio Scita
- Fondazione Istituto FIRC di Oncologia Molecolare (IFOM), Via Adamello 16, 20139, Milan, Italy; Department of Hemato-Oncology (DIPO), University of Milan, Italy
| | - Jürgen Weitz
- Department of Visceral, Thoracic and Vascular Surgery, University Hospital Carl Gustav Carus, Technische Universität Dresden, Germany
| | - Thilo Welsch
- Department of Visceral, Thoracic and Vascular Surgery, University Hospital Carl Gustav Carus, Technische Universität Dresden, Germany.
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263
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Slade L, Pulinilkunnil T. The MiTF/TFE Family of Transcription Factors: Master Regulators of Organelle Signaling, Metabolism, and Stress Adaptation. Mol Cancer Res 2017; 15:1637-1643. [PMID: 28851811 DOI: 10.1158/1541-7786.mcr-17-0320] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Revised: 08/08/2017] [Accepted: 08/24/2017] [Indexed: 11/16/2022]
Abstract
The microphthalmia family (MITF, TFEB, TFE3, and TFEC) of transcription factors is emerging as global regulators of cancer cell survival and energy metabolism, both through the promotion of lysosomal genes as well as newly characterized targets, such as oxidative metabolism and the oxidative stress response. In addition, MiT/TFE factors can regulate lysosomal signaling, which includes the mTORC1 and Wnt/β-catenin pathways, which are both substantial contributors to oncogenic signaling. This review describes recent discoveries in MiT/TFE research and how they impact multiple cancer subtypes. Furthermore, the literature relating to TFE-fusion proteins in cancers and the potential mechanisms through which these genomic rearrangements promote tumorigenesis is reviewed. Likewise, the emerging function of the Folliculin (FLCN) tumor suppressor in negatively regulating the MiT/TFE family and how loss of this pathway promotes cancer is examined. Recent reports are also presented that relate to the role of MiT/TFE-driven lysosomal biogenesis in sustaining cancer cell metabolism and signaling in nutrient-limiting conditions. Finally, a discussion is provided on the future directions and unanswered questions in the field. In summary, the research surrounding the MiT/TFE family indicates that these transcription factors are promising therapeutic targets and biomarkers for cancers that thrive in stressful niches. Mol Cancer Res; 15(12); 1637-43. ©2017 AACR.
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Affiliation(s)
- Logan Slade
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, Dalhousie University, Dalhousie Medicine New Brunswick, New Brunswick, Canada
| | - Thomas Pulinilkunnil
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, Dalhousie University, Dalhousie Medicine New Brunswick, New Brunswick, Canada.
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264
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Choi J, Kim H, Bae YK, Cheong H. REP1 Modulates Autophagy and Macropinocytosis to Enhance Cancer Cell Survival. Int J Mol Sci 2017; 18:ijms18091866. [PMID: 28846638 PMCID: PMC5618515 DOI: 10.3390/ijms18091866] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 08/21/2017] [Accepted: 08/22/2017] [Indexed: 01/18/2023] Open
Abstract
Rab escort protein 1 (REP1), a component of the Rab geranyl-geranyltransferase 2 complex, plays a role in Rab protein recruitment in proper vesicles during vesicle trafficking. In addition to having well-known tissue degenerative phenotypes in the REP1 mutant, REP1 is tightly associated with cancer development and contributes to cell growth and survival. However, the functional mechanism of REP1 in cancer progression is largely uninvestigated. Here, we show that REP1 plays a crucial role in regulating mammalian target of rapamycin (mTOR) signaling and its downstream pathways, as well as autophagy and macropinocytosis, which are essential for cancer cell survival during metabolic stresses including starvation. REP1 small interfering RNA (siRNA) treatment downregulates mTORC1 activity in growing media, but blocks autophagosome formation under nutrient-depleted conditions. In contrast to the mild decrease of lysosomal enzyme activity seen in REP1 depletion, in REP1 knockdown the subcellular localization of lysosomes is altered, and localization of REP1 itself is modulated by intracellular nutrient levels and mTOR activity. Furthermore, REP1 depletion increases macro pinocytosis which may be a feedback mechanism to compensate autophagy inhibition. Concomitant treatment with macropinocytosis inhibitor and REP1siRNAresults in more significant cell death than autophagy blockade with REP1 knockdown. Therefore, REP1-mediated autophagy and lysosomal degradation processes act as novel regulatory mechanisms to support cancer cell survival, which can be further investigated as a potential cancer-targeting pathway.
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Affiliation(s)
- Jungwon Choi
- Tumor Microenvironment Research Branch, Research Institute, National Cancer Center, 323 Ilsan-ro, Ilsandong-gu,10 Goyang-si, Gyeonggi-do 10408, Korea.
| | - Hyena Kim
- Tumor Microenvironment Research Branch, Research Institute, National Cancer Center, 323 Ilsan-ro, Ilsandong-gu,10 Goyang-si, Gyeonggi-do 10408, Korea.
| | - Young Ki Bae
- Tumor Microenvironment Research Branch, Research Institute, National Cancer Center, 323 Ilsan-ro, Ilsandong-gu,10 Goyang-si, Gyeonggi-do 10408, Korea.
| | - Heesun Cheong
- Tumor Microenvironment Research Branch, Research Institute, National Cancer Center, 323 Ilsan-ro, Ilsandong-gu,10 Goyang-si, Gyeonggi-do 10408, Korea.
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265
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Shibutani S, Okazaki H, Iwata H. Dynamin-dependent amino acid endocytosis activates mechanistic target of rapamycin complex 1 (mTORC1). J Biol Chem 2017; 292:18052-18061. [PMID: 28808055 DOI: 10.1074/jbc.m117.776443] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 08/03/2017] [Indexed: 11/06/2022] Open
Abstract
The mechanistic target of rapamycin complex 1 (mTORC1) is a master regulator of protein synthesis and potential target for modifying cellular metabolism in various conditions, including cancer and aging. mTORC1 activity is tightly regulated by the availability of extracellular amino acids, and previous studies have revealed that amino acids in the extracellular fluid are transported to the lysosomal lumen. There, amino acids induce recruitment of cytoplasmic mTORC1 to the lysosome by the Rag GTPases, followed by mTORC1 activation by the small GTPase Ras homolog enriched in brain (Rheb). However, how the extracellular amino acids reach the lysosomal lumen and activate mTORC1 remains unclear. Here, we show that amino acid uptake by dynamin-dependent endocytosis plays a critical role in mTORC1 activation. We found that mTORC1 is inactivated when endocytosis is inhibited by overexpression of a dominant-negative form of dynamin 2 or by pharmacological inhibition of dynamin or clathrin. Consistently, the recruitment of mTORC1 to the lysosome was suppressed by the dynamin inhibition. The activity and lysosomal recruitment of mTORC1 were rescued by increasing intracellular amino acids via cycloheximide exposure or by Rag overexpression, indicating that amino acid deprivation is the main cause of mTORC1 inactivation via the dynamin inhibition. We further show that endocytosis inhibition does not induce autophagy even though mTORC1 inactivation is known to strongly induce autophagy. These findings open new perspectives for the use of endocytosis inhibitors as potential agents that can effectively inhibit nutrient utilization and shut down the upstream signals that activate mTORC1.
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Affiliation(s)
- Shusaku Shibutani
- From the Laboratory of Veterinary Hygiene, Joint Faculty of Veterinary Medicine, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8515, Japan
| | - Hana Okazaki
- From the Laboratory of Veterinary Hygiene, Joint Faculty of Veterinary Medicine, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8515, Japan
| | - Hiroyuki Iwata
- From the Laboratory of Veterinary Hygiene, Joint Faculty of Veterinary Medicine, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8515, Japan
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266
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Oizel K, Chauvin C, Oliver L, Gratas C, Geraldo F, Jarry U, Scotet E, Rabe M, Alves-Guerra MC, Teusan R, Gautier F, Loussouarn D, Compan V, Martinou JC, Vallette FM, Pecqueur C. Efficient Mitochondrial Glutamine Targeting Prevails Over Glioblastoma Metabolic Plasticity. Clin Cancer Res 2017; 23:6292-6304. [PMID: 28720668 DOI: 10.1158/1078-0432.ccr-16-3102] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Revised: 04/24/2017] [Accepted: 07/13/2017] [Indexed: 11/16/2022]
Abstract
Purpose: Glioblastoma (GBM) is the most common and malignant form of primary human brain tumor in adults, with an average survival at diagnosis of 18 months. Metabolism is a new attractive therapeutic target in cancer; however, little is known about metabolic heterogeneity and plasticity within GBM tumors. We therefore aimed to investigate metabolic phenotyping of primary cultures in the context of molecular tumor heterogeneity to provide a proof of concept for personalized metabolic targeting of GBM.Experimental Design: We have analyzed extensively several primary GBM cultures using transcriptomics, metabolic phenotyping assays, and mitochondrial respirometry.Results: We found that metabolic phenotyping clearly identifies 2 clusters, GLNHigh and GLNLow, mainly based on metabolic plasticity and glutamine (GLN) utilization. Inhibition of glutamine metabolism slows the in vitro and in vivo growth of GLNHigh GBM cultures despite metabolic adaptation to nutrient availability, in particular by increasing pyruvate shuttling into mitochondria. Furthermore, phenotypic and molecular analyses show that highly proliferative GLNHigh cultures are CD133neg and display a mesenchymal signature in contrast to CD133pos GLNLow GBM cells.Conclusions: Our results show that metabolic phenotyping identified an essential metabolic pathway in a GBM cell subtype, and provide a proof of concept for theranostic metabolic targeting. Clin Cancer Res; 23(20); 6292-304. ©2017 AACR.
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Affiliation(s)
| | - Cynthia Chauvin
- CRCINA, INSERM, Université de Nantes, France.,Labex IGO "Immunotherapy, Graft, Oncology."
| | - Lisa Oliver
- CRCINA, INSERM, Université de Nantes, France.,Centre Hospitalier-Universitaire (CHU) de Nantes, Nantes, France.,Equipe labellisée Ligue contre le Cancer.,Labex IGO "Immunotherapy, Graft, Oncology."
| | - Catherine Gratas
- CRCINA, INSERM, Université de Nantes, France.,Centre Hospitalier-Universitaire (CHU) de Nantes, Nantes, France.,Equipe labellisée Ligue contre le Cancer
| | | | - Ulrich Jarry
- CRCINA, INSERM, Université de Nantes, France.,Labex IGO "Immunotherapy, Graft, Oncology."
| | - Emmanuel Scotet
- CRCINA, INSERM, Université de Nantes, France.,Labex IGO "Immunotherapy, Graft, Oncology."
| | - Marion Rabe
- CRCINA, INSERM, Université de Nantes, France
| | - Marie-Clotilde Alves-Guerra
- Inserm, U1016, Institut Cochin, Paris, France.,CNRS, UMR 8104, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Raluca Teusan
- Institut du thorax, INSERM, CNRS, UNIV Nantes, Nantes, France
| | - Fabien Gautier
- CRCINA, INSERM, Université de Nantes, France.,Institut de Cancérologie de l'Ouest, René Gauducheau, St Herblain, France
| | - Delphine Loussouarn
- CRCINA, INSERM, Université de Nantes, France.,Centre Hospitalier-Universitaire (CHU) de Nantes, Nantes, France
| | - Vincent Compan
- Institute of Functional Genomics, Labex ICST, CNRS, UMR 5203, University of Montpellier, Montpellier, France.,INSERM U1191, Montpellier, France
| | | | - François M Vallette
- CRCINA, INSERM, Université de Nantes, France. .,Institut de Cancérologie de l'Ouest, René Gauducheau, St Herblain, France.,Equipe labellisée Ligue contre le Cancer.,Labex IGO "Immunotherapy, Graft, Oncology."
| | - Claire Pecqueur
- CRCINA, INSERM, Université de Nantes, France. .,Equipe labellisée Ligue contre le Cancer.,Labex IGO "Immunotherapy, Graft, Oncology."
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267
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Collagen-derived proline promotes pancreatic ductal adenocarcinoma cell survival under nutrient limited conditions. Nat Commun 2017; 8:16031. [PMID: 28685754 PMCID: PMC5504351 DOI: 10.1038/ncomms16031] [Citation(s) in RCA: 262] [Impact Index Per Article: 37.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 05/23/2017] [Indexed: 12/12/2022] Open
Abstract
Tissue architecture contributes to pancreatic ductal adenocarcinoma (PDAC) phenotypes. Cancer cells within PDAC form gland-like structures embedded in a collagen-rich meshwork where nutrients and oxygen are scarce. Altered metabolism is needed for tumour cells to survive in this environment, but the metabolic modifications that allow PDAC cells to endure these conditions are incompletely understood. Here we demonstrate that collagen serves as a proline reservoir for PDAC cells to use as a nutrient source when other fuels are limited. We show PDAC cells are able to take up collagen fragments, which can promote PDAC cell survival under nutrient limited conditions, and that collagen-derived proline contributes to PDAC cell metabolism. Finally, we show that proline oxidase (PRODH1) is required for PDAC cell proliferation in vitro and in vivo. Collectively, our results indicate that PDAC extracellular matrix represents a nutrient reservoir for tumour cells highlighting the metabolic flexibility of this cancer. Cancer cells adapt their metabolism to survive limited nutrient availability. Here, the authors show that in conditions of limited glucose or glutamine availability, pancreatic ductal adenocarcinoma cells can use collagen-derived proline to foster the TCA cycle and allow cell survival both in vitro and in vivo.
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268
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Kim B, Li J, Jang C, Arany Z. Glutamine fuels proliferation but not migration of endothelial cells. EMBO J 2017; 36:2321-2333. [PMID: 28659379 DOI: 10.15252/embj.201796436] [Citation(s) in RCA: 155] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 05/26/2017] [Accepted: 05/30/2017] [Indexed: 12/14/2022] Open
Abstract
Endothelial metabolism is a key regulator of angiogenesis. Glutamine metabolism in endothelial cells (ECs) has been poorly studied. We used genetic modifications and 13C tracing approaches to define glutamine metabolism in these cells. Glutamine supplies the majority of carbons in the tricyclic acid (TCA) cycle of ECs and contributes to lipid biosynthesis via reductive carboxylation. EC-specific deletion in mice of glutaminase, the initial enzyme in glutamine catabolism, markedly blunts angiogenesis. In cell culture, glutamine deprivation or inhibition of glutaminase prevents EC proliferation, but does not prevent cell migration, which relies instead on aerobic glycolysis. Without glutamine catabolism, there is near complete loss of TCA intermediates, with no compensation from glucose-derived anaplerosis. Mechanistically, addition of exogenous alpha-ketoglutarate replenishes TCA intermediates and rescues cellular growth, but simultaneously unveils a requirement for Rac1-dependent macropinocytosis to provide non-essential amino acids, including asparagine. Together, these data outline the dependence of ECs on glutamine for cataplerotic processes; the need for glutamine as a nitrogen source for generation of biomass; and the distinct roles of glucose and glutamine in EC biology.
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Affiliation(s)
- Boa Kim
- Department of Medicine, Cardiovascular Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.,Institute of Diabetes Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Jia Li
- Department of Medicine, Cardiovascular Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.,Institute of Diabetes Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Cholsoon Jang
- Department of Medicine, Cardiovascular Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.,Institute of Diabetes Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.,Chemistry and Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Zoltan Arany
- Department of Medicine, Cardiovascular Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA .,Institute of Diabetes Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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269
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Abstract
Mutations of KRAS are found in a variety of human malignancies, including in pancreatic cancer, colorectal cancer, and non-small cell lung cancer at high frequency. To date, no effective treatments that target mutant variants of KRAS have been introduced into clinical practice. In recent years, a number of studies have shown that the oncogene KRAS plays a critical role in controlling cancer metabolism by orchestrating multiple metabolic changes. One of the metabolic hallmarks of malignant tumor cells is their dependency on aerobic glycolysis, known as the Warburg effect. The role of KRAS signaling in the regulation of aerobic glycolysis has been reported in several types of cancer. KRAS-driven cancers are characterized by altered metabolic pathways involving enhanced nutrients uptake, enhanced glycolysis, enhanced glutaminolysis, and elevated synthesis of fatty acids and nucleotides. However, Just how mutated KRAS can coordinate the metabolic shift to promote tumor growth and whether specific metabolic pathways are essential for the tumorigenesis of KRAS-driven cancers are questions which remain to be answered. In this context, the aim of this review is to summarize current data on KRAS-related metabolic alterations in cancer cells. Given that cancer cells rely on changes in metabolism to support their growth and survival, the targeting of metabolic processes may be a potential strategy for treating KRAS-driven cancers.
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Affiliation(s)
- Kenji Kawada
- Department of Surgery, Graduate School of Medicine, Kyoto University, 54 Shogoin-Kawara-cho, Sakyo-ku, Kyoto, 606-8507, Japan.
| | - Kosuke Toda
- Department of Surgery, Graduate School of Medicine, Kyoto University, 54 Shogoin-Kawara-cho, Sakyo-ku, Kyoto, 606-8507, Japan
| | - Yoshiharu Sakai
- Department of Surgery, Graduate School of Medicine, Kyoto University, 54 Shogoin-Kawara-cho, Sakyo-ku, Kyoto, 606-8507, Japan
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270
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Gu Y, Albuquerque CP, Braas D, Zhang W, Villa GR, Bi J, Ikegami S, Masui K, Gini B, Yang H, Gahman TC, Shiau AK, Cloughesy TF, Christofk HR, Zhou H, Guan KL, Mischel PS. mTORC2 Regulates Amino Acid Metabolism in Cancer by Phosphorylation of the Cystine-Glutamate Antiporter xCT. Mol Cell 2017. [PMID: 28648777 DOI: 10.1016/j.molcel.2017.05.030] [Citation(s) in RCA: 139] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Mutations in cancer reprogram amino acid metabolism to drive tumor growth, but the molecular mechanisms are not well understood. Using an unbiased proteomic screen, we identified mTORC2 as a critical regulator of amino acid metabolism in cancer via phosphorylation of the cystine-glutamate antiporter xCT. mTORC2 phosphorylates serine 26 at the cytosolic N terminus of xCT, inhibiting its activity. Genetic inhibition of mTORC2, or pharmacologic inhibition of the mammalian target of rapamycin (mTOR) kinase, promotes glutamate secretion, cystine uptake, and incorporation into glutathione, linking growth factor receptor signaling with amino acid uptake and utilization. These results identify an unanticipated mechanism regulating amino acid metabolism in cancer, enabling tumor cells to adapt to changing environmental conditions.
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Affiliation(s)
- Yuchao Gu
- Department of Molecular and Medical Pharmacology, David Geffen UCLA School of Medicine, Los Angeles, CA 90095, USA; Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, CA 92093, USA
| | - Claudio P Albuquerque
- Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, CA 92093, USA
| | - Daniel Braas
- Department of Molecular and Medical Pharmacology, David Geffen UCLA School of Medicine, Los Angeles, CA 90095, USA; UCLA Metabolomics Center, Los Angeles, CA 90095, USA
| | - Wei Zhang
- Department of Medicine, UCSD School of Medicine, La Jolla, CA 92093, USA
| | - Genaro R Villa
- Department of Molecular and Medical Pharmacology, David Geffen UCLA School of Medicine, Los Angeles, CA 90095, USA; Medical Scientist Training Program, David Geffen UCLA School of Medicine, Los Angeles, CA 90095, USA; Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, CA 92093, USA
| | - Junfeng Bi
- Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, CA 92093, USA
| | - Shiro Ikegami
- Division of Neurological Surgery, Chiba Cancer Center, Chiba 260-8717, Japan
| | - Kenta Masui
- Department of Pathology, Tokyo Women's Medical University, Tokyo 162-8666, Japan
| | - Beatrice Gini
- Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Huijun Yang
- Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, CA 92093, USA
| | - Timothy C Gahman
- Small Molecule Discovery Program, Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, CA 92093, USA
| | - Andrew K Shiau
- Small Molecule Discovery Program, Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, CA 92093, USA
| | - Timothy F Cloughesy
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Heather R Christofk
- Department of Molecular and Medical Pharmacology, David Geffen UCLA School of Medicine, Los Angeles, CA 90095, USA; UCLA Metabolomics Center, Los Angeles, CA 90095, USA
| | - Huilin Zhou
- Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, CA 92093, USA; Department of Cellular and Molecular Medicine, UCSD School of Medicine, La Jolla, CA 92093, USA; Moores Cancer Center, UCSD School of Medicine, La Jolla, CA 92093 USA
| | - Kun-Liang Guan
- Department of Pharmacology, UCSD School of Medicine, La Jolla, CA 92093, USA; Moores Cancer Center, UCSD School of Medicine, La Jolla, CA 92093 USA
| | - Paul S Mischel
- Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, CA 92093, USA; Department of Pathology, UCSD School of Medicine, La Jolla, CA 92093 USA; Moores Cancer Center, UCSD School of Medicine, La Jolla, CA 92093 USA.
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271
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Abstract
Autophagy, a self-eating machinery, has been reported as an adaptive response to maintain metabolic homeostasis when cancer cells encounter stress. It has been appreciated that autophagy acts as a double-edge sword to decide the fate of cancer cells upon stress factors, molecular subtypes, and microenvironmental conditions. Currently, the majority of evidence support that autophagy in cancer cells is a vital mechanism bringing on resistance to current and prospective treatments, yet whether autophagy affects the anticancer immune response remains unclear and controversial. Accumulated studies have demonstrated that triggering autophagy is able to facilitate anticancer immunity due to an increase in immunogenicity, whereas other studies suggested that autophagy is likely to disarm anticancer immunity mediated by cytotoxic T cells and nature killer (NK) cells. Hence, this contradiction needs to be elucidated. In this review, we discuss the role of autophagy in cancer cells per se and in cancer microenvironment as well as its dual regulatory roles in immune surveillance through modulating presentation of tumor antigens, development of immune cells, and expression of immune checkpoints. We further focus on emerging roles of autophagy induced by current treatments and its impact on anticancer immune response, and illustrate the pros and cons of utilizing autophagy in cancer immunotherapy based on preclinical references.
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272
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Saxton RA, Sabatini DM. mTOR Signaling in Growth, Metabolism, and Disease. Cell 2017; 168:960-976. [PMID: 28283069 DOI: 10.1016/j.cell.2017.02.004] [Citation(s) in RCA: 3832] [Impact Index Per Article: 547.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2016] [Revised: 01/22/2017] [Accepted: 02/01/2017] [Indexed: 12/13/2022]
Abstract
The mechanistic target of rapamycin (mTOR) coordinates eukaryotic cell growth and metabolism with environmental inputs, including nutrients and growth factors. Extensive research over the past two decades has established a central role for mTOR in regulating many fundamental cell processes, from protein synthesis to autophagy, and deregulated mTOR signaling is implicated in the progression of cancer and diabetes, as well as the aging process. Here, we review recent advances in our understanding of mTOR function, regulation, and importance in mammalian physiology. We also highlight how the mTOR signaling network contributes to human disease and discuss the current and future prospects for therapeutically targeting mTOR in the clinic.
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Affiliation(s)
- Robert A Saxton
- Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142, USA; Department of Biology, Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Koch Institute for Integrative Cancer Research, 77 Massachusetts Avenue, Cambridge, MA 02139, USA; Broad Institute of Harvard and Massachusetts Institute of Technology, 415 Main Street, Cambridge, MA 02142, USA
| | - David M Sabatini
- Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142, USA; Department of Biology, Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Koch Institute for Integrative Cancer Research, 77 Massachusetts Avenue, Cambridge, MA 02139, USA; Broad Institute of Harvard and Massachusetts Institute of Technology, 415 Main Street, Cambridge, MA 02142, USA.
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273
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Mayers JR, Vander Heiden MG. Nature and Nurture: What Determines Tumor Metabolic Phenotypes? Cancer Res 2017; 77:3131-3134. [DOI: 10.1158/0008-5472.can-17-0165] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Revised: 03/08/2017] [Accepted: 03/21/2017] [Indexed: 11/16/2022]
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274
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Buckley CM, King JS. Drinking problems: mechanisms of macropinosome formation and maturation. FEBS J 2017; 284:3778-3790. [DOI: 10.1111/febs.14115] [Citation(s) in RCA: 93] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Revised: 04/25/2017] [Accepted: 05/17/2017] [Indexed: 11/30/2022]
Affiliation(s)
- Catherine M. Buckley
- Department of Biomedical Sciences Centre for Membrane Interactions and Dynamics University of Sheffield UK
- Bateson Centre University of Sheffield UK
| | - Jason S. King
- Department of Biomedical Sciences Centre for Membrane Interactions and Dynamics University of Sheffield UK
- Bateson Centre University of Sheffield UK
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275
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Vander Heiden MG, DeBerardinis RJ. Understanding the Intersections between Metabolism and Cancer Biology. Cell 2017; 168:657-669. [PMID: 28187287 DOI: 10.1016/j.cell.2016.12.039] [Citation(s) in RCA: 1412] [Impact Index Per Article: 201.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 12/23/2016] [Accepted: 12/27/2016] [Indexed: 12/12/2022]
Abstract
Transformed cells adapt metabolism to support tumor initiation and progression. Specific metabolic activities can participate directly in the process of transformation or support the biological processes that enable tumor growth. Exploiting cancer metabolism for clinical benefit requires defining the pathways that are limiting for cancer progression and understanding the context specificity of metabolic preferences and liabilities in malignant cells. Progress toward answering these questions is providing new insight into cancer biology and can guide the more effective targeting of metabolism to help patients.
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Affiliation(s)
- Matthew G Vander Heiden
- The Koch Institute for Integrative Cancer Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Dana-Farber Cancer Institute, Boston, MA 02115, USA.
| | - Ralph J DeBerardinis
- Children's Medical Center Research Institute, Department of Pediatrics, and Eugene McDermott Center for Human Growth and Development, The University of Texas Southwestern Medical Center, Dallas, TX 75390.
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276
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Kitazawa S, Nishizawa S, Nakagawa H, Funata M, Nishimura K, Soga T, Hara T. Cancer with low cathepsin D levels is susceptible to vacuolar (H + )-ATPase inhibition. Cancer Sci 2017; 108:1185-1193. [PMID: 28317223 PMCID: PMC5480082 DOI: 10.1111/cas.13240] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 03/09/2017] [Accepted: 03/13/2017] [Indexed: 01/17/2023] Open
Abstract
Vacuolar (H+)‐ATPases (V‐ATPases) have important roles in the supply of nutrients to tumors by mediating autophagy and the endocytic uptake of extracellular fluids. Accordingly, V‐ATPases are attractive therapeutic targets for cancer. However, the clinical use of V‐ATPase inhibitors as anticancer drugs has not been realized, possibly owing to their high toxicity in humans. Inhibition of V‐ATPase may be an appropriate strategy in highly susceptible cancers. In this study, we explored markers of V‐ATPase inhibitor sensitivity. V‐ATPase inhibitors led to pH impairment in acidic intracellular compartments, suppression of macropinocytosis, and decreased intracellular amino acid levels. The sensitivity of cells to V‐ATPase inhibitors was correlated with low cathepsin D expression, and cancer cells showed increased sensitivity to V‐ATPase inhibitors after pretreatment with a cathepsin D inhibitor and siRNA targeting the cathepsin D gene (CTSD). In addition, V‐ATPase inhibitor treatment led to the induction of the amino acid starvation response, upregulation of endoplasmic reticulum stress markers, and suppression of mammalian target of rapamycin (mTOR) signaling in cells expressing low levels of cathepsin D. Some colorectal cancer patients showed the downregulation of cathepsin D in tumor tissues compared with matched normal tissues. These findings indicate that V‐ATPase inhibitors are promising therapeutic options for cancers with downregulated cathepsin D.
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Affiliation(s)
- Satoshi Kitazawa
- Oncology Drug Discovery Unit, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Fujisawa, Japan
| | - Satoru Nishizawa
- Oncology Drug Discovery Unit, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Fujisawa, Japan
| | - Hideyuki Nakagawa
- Biomolecular Research Laboratories, Takeda Pharmaceutical Company Limited, Fujisawa, Japan
| | - Masaaki Funata
- Biomolecular Research Laboratories, Takeda Pharmaceutical Company Limited, Fujisawa, Japan
| | - Kazuho Nishimura
- Oncology Drug Discovery Unit, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Fujisawa, Japan
| | - Tomoyoshi Soga
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Japan
| | - Takahito Hara
- Oncology Drug Discovery Unit, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Fujisawa, Japan
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277
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Selwan EM, Edinger AL. Branched chain amino acid metabolism and cancer: the importance of keeping things in context. Transl Cancer Res 2017; 6:S578-S584. [PMID: 30613481 PMCID: PMC6319930 DOI: 10.21037/tcr.2017.05.05] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Elizabeth M Selwan
- Department of Developmental and Cell Biology, University of California Irvine, Irvine, CA 92697-2300, USA
| | - Aimee L Edinger
- Department of Developmental and Cell Biology, University of California Irvine, Irvine, CA 92697-2300, USA
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278
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Bates PJ, Reyes-Reyes EM, Malik MT, Murphy EM, O'Toole MG, Trent JO. G-quadruplex oligonucleotide AS1411 as a cancer-targeting agent: Uses and mechanisms. Biochim Biophys Acta Gen Subj 2017; 1861:1414-1428. [PMID: 28007579 DOI: 10.1016/j.bbagen.2016.12.015] [Citation(s) in RCA: 197] [Impact Index Per Article: 28.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 12/16/2016] [Accepted: 12/17/2016] [Indexed: 02/08/2023]
Abstract
BACKGROUND AS1411 is a 26-mer G-rich DNA oligonucleotide that forms a variety of G-quadruplex structures. It was identified based on its cancer-selective antiproliferative activity and subsequently determined to be an aptamer to nucleolin, a multifunctional protein that preferentially binds quadruplex nucleic acids and which is present at high levels on the surface of cancer cells. AS1411 has exceptionally efficient cellular internalization compared to non-quadruplex DNA sequences. SCOPE OF REVIEW Recent developments related to AS1411 will be examined, with a focus on its use for targeted delivery of therapeutic and imaging agents. MAJOR CONCLUSIONS Numerous research groups have used AS1411 as a targeting agent to deliver nanoparticles, oligonucleotides, and small molecules into cancer cells. Studies in animal models have demonstrated that AS1411-linked materials can accumulate selectively in tumors following systemic administration. The mechanism underlying the cancer-targeting ability of AS1411 is not completely understood, but recent studies suggest a model that involves: (1) initial uptake by macropinocytosis, a form of endocytosis prevalent in cancer cells; (2) stimulation of macropinocytosis by a nucleolin-dependent mechanism resulting in further uptake; and (3) disruption of nucleolin-mediated trafficking and efflux leading to cargoes becoming trapped inside cancer cells. SIGNIFICANCE Human trials have indicated that AS1411 is safe and can induce durable remissions in a few patients, but new strategies are needed to maximize its clinical impact. A better understanding of the mechanisms by which AS1411 targets and kills cancer cells may hasten the development of promising technologies using AS1411-linked nanoparticles or conjugates for cancer-targeted therapy and imaging. This article is part of a Special Issue entitled "G-quadruplex" Guest Editor: Dr. Concetta Giancola and Dr. Daniela Montesarchio.
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Affiliation(s)
- Paula J Bates
- Department of Medicine, University of Louisville, USA; James Graham Brown Cancer Center, University of Louisville, USA.
| | | | - Mohammad T Malik
- Department of Medicine, University of Louisville, USA; James Graham Brown Cancer Center, University of Louisville, USA
| | - Emily M Murphy
- Department of Biomedical Engineering, University of Louisville, USA
| | - Martin G O'Toole
- Department of Biomedical Engineering, University of Louisville, USA
| | - John O Trent
- Department of Medicine, University of Louisville, USA; James Graham Brown Cancer Center, University of Louisville, USA
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279
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Shargh VH, Hondermarck H, Liang M. Gelatin-albumin hybrid nanoparticles as matrix metalloproteinases-degradable delivery systems for breast cancer therapy. Nanomedicine (Lond) 2017; 12:977-989. [PMID: 28440712 DOI: 10.2217/nnm-2016-0419] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
AIM To develop matrix metalloproteinase-responsive gelatin-albumin hybrid nanoparticles encapsulating a selective tropomyosin receptor kinase A (TrkA) inhibitor GNF-5837 (Gel-Alb-GNF HNPs) and to demonstrate their anticancer effects in breast cancer. METHODS Gel-Alb-GNF HNPs were prepared using a pH-controlled complexation process from cationic gelatin, dextran sulfate and albumin-bound GNF-5837. The anticancer activities of Gel-Alb-GNF HNPs were tested in a panel of subtype-specific breast cancer cell lines. RESULTS Gel-Alb-GNF HNPs (∼130 nm) displayed excellent stability and matrix metalloproteinase-triggered drug release. Compared with GNF-5837 alone, Gel-Alb-GNF HNPs not only significantly enhanced the antiproliferative and anti-invasive effects but also restored the apoptosis of cancer cells. CONCLUSION Gel-Alb-GNF HNPs may be adaptable for stand-alone therapies or used in combination with traditional chemotherapies for breast cancer treatment.
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Affiliation(s)
- Vahid Heravi Shargh
- School of Biomedical Sciences & Pharmacy, Faculty of Health & Medicine, University of Newcastle, Callaghan, NSW 2308, Australia.,Hunter Medical Research Institute, New Lambton Heights, NSW 2305, Australia
| | - Hubert Hondermarck
- School of Biomedical Sciences & Pharmacy, Faculty of Health & Medicine, University of Newcastle, Callaghan, NSW 2308, Australia.,Hunter Medical Research Institute, New Lambton Heights, NSW 2305, Australia
| | - Mingtao Liang
- School of Biomedical Sciences & Pharmacy, Faculty of Health & Medicine, University of Newcastle, Callaghan, NSW 2308, Australia.,Hunter Medical Research Institute, New Lambton Heights, NSW 2305, Australia
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280
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Kim LC, Cook RS, Chen J. mTORC1 and mTORC2 in cancer and the tumor microenvironment. Oncogene 2017; 36:2191-2201. [PMID: 27748764 PMCID: PMC5393956 DOI: 10.1038/onc.2016.363] [Citation(s) in RCA: 288] [Impact Index Per Article: 41.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Revised: 08/04/2016] [Accepted: 08/15/2016] [Indexed: 02/06/2023]
Abstract
The mammalian target of rapamycin (mTOR) is a crucial signaling node that integrates environmental cues to regulate cell survival, proliferation and metabolism, and is often deregulated in human cancer. mTOR kinase acts in two functionally distinct complexes, mTOR complex 1 (mTORC1) and 2 (mTORC2), whose activities and substrate specificities are regulated by complex co-factors. Deregulation of this centralized signaling pathway has been associated with a variety of human diseases including diabetes, neurodegeneration and cancer. Although mTORC1 signaling has been extensively studied in cancer, recent discoveries indicate a subset of human cancers harboring amplifications in mTORC2-specific genes as the only actionable genomic alterations, suggesting a distinct role for mTORC2 in cancer as well. This review will summarize recent advances in dissecting the relative contributions of mTORC1 versus mTORC2 in cancer, their role in tumor-associated blood vessels and tumor immunity, and provide an update on mTOR inhibitors.
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Affiliation(s)
- Laura C. Kim
- Department of Cancer Biology, Vanderbilt University, Nashville, TN 37232
| | - Rebecca S. Cook
- Department of Cancer Biology, Vanderbilt University, Nashville, TN 37232
- Vanderbilt-Ingram Cancer Center, Vanderbilt University, Nashville, TN 37232
| | - Jin Chen
- Department of Cancer Biology, Vanderbilt University, Nashville, TN 37232
- Division of Rheumatology and Immunology, Department of Medicine, Vanderbilt University, Nashville, TN 37232
- Vanderbilt-Ingram Cancer Center, Vanderbilt University, Nashville, TN 37232
- Department of Cell & Developmental Biology, Vanderbilt University, Nashville, TN 37232
- Veterans Affairs Medical Center, Tennessee Valley Healthcare System, Nashville, TN 37212
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281
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Zhang J, Pavlova NN, Thompson CB. Cancer cell metabolism: the essential role of the nonessential amino acid, glutamine. EMBO J 2017; 36:1302-1315. [PMID: 28420743 DOI: 10.15252/embj.201696151] [Citation(s) in RCA: 404] [Impact Index Per Article: 57.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 01/16/2017] [Accepted: 01/18/2017] [Indexed: 12/24/2022] Open
Abstract
Biochemistry textbooks and cell culture experiments seem to be telling us two different things about the significance of external glutamine supply for mammalian cell growth and proliferation. Despite the fact that glutamine is a nonessential amino acid that can be synthesized by cells from glucose-derived carbons and amino acid-derived ammonia, most mammalian cells in tissue culture cannot proliferate or even survive in an environment that does not contain millimolar levels of glutamine. Not only are the levels of glutamine in standard tissue culture media at least ten-fold higher than other amino acids, but glutamine is also the most abundant amino acid in the human bloodstream, where it is assiduously maintained at approximately 0.5 mM through a combination of dietary uptake, de novo synthesis, and muscle protein catabolism. The complex metabolic logic of the proliferating cancer cells' appetite for glutamine-which goes far beyond satisfying their protein synthesis requirements-has only recently come into focus. In this review, we examine the diversity of biosynthetic and regulatory uses of glutamine and their role in proliferation, stress resistance, and cellular identity, as well as discuss the mechanisms that cells utilize in order to adapt to glutamine limitation.
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Affiliation(s)
- Ji Zhang
- Department of Cancer Biology and Genetics, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Natalya N Pavlova
- Department of Cancer Biology and Genetics, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Craig B Thompson
- Department of Cancer Biology and Genetics, Memorial Sloan Kettering Cancer Center, New York, NY, USA
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282
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SNAT7 is the primary lysosomal glutamine exporter required for extracellular protein-dependent growth of cancer cells. Proc Natl Acad Sci U S A 2017; 114:E3602-E3611. [PMID: 28416685 DOI: 10.1073/pnas.1617066114] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Lysosomes degrade cellular components sequestered by autophagy or extracellular material internalized by endocytosis and phagocytosis. The macromolecule building blocks released by lysosomal hydrolysis are then exported to the cytosol by lysosomal transporters, which remain undercharacterized. In this study, we designed an in situ assay of lysosomal amino acid export based on the transcription factor EB (TFEB), a master regulator of lysosomal biogenesis that detects lysosomal storage. This assay was used to screen candidate lysosomal transporters, leading to the identification of sodium-coupled neutral amino acid transporter 7 (SNAT7), encoded by the SLC38A7 gene, as a lysosomal transporter highly selective for glutamine and asparagine. Cell fractionation confirmed the lysosomal localization of SNAT7, and flux measurements confirmed its substrate selectivity and showed a strong activation by the lysosomal pH gradient. Interestingly, gene silencing or editing experiments revealed that SNAT7 is the primary permeation pathway for glutamine across the lysosomal membrane and it is required for growth of cancer cells in a low free-glutamine environment, when macropinocytosis and lysosomal degradation of extracellular proteins are used as an alternative source of amino acids. SNAT7 may, thus, represent a novel target for glutamine-related anticancer therapies.
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283
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Thompson CB, Palm W. Reexamining How Cancer Cells Exploit the Body's Metabolic Resources. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2017; 81:67-72. [PMID: 28396524 DOI: 10.1101/sqb.2016.81.030734] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
A key feature of multicellular life is the sharing of nutritional resources by all cells of the organism. In animals, the allocation of nutrients to individual cells is not determined in a cell-autonomous fashion. Instead, growth factor and hormonal signaling pathways have evolved to regulate cellular nutrient uptake, which prevents individual cells from parasitizing the organism's metabolic reserves. Cancer is a condition where the highly ordered regulation of nutrient distribution is disrupted. During carcinogenesis, transformed cells acquire mutations in signaling pathways that render nutrient uptake cell-autonomous. A deeper understanding of how the acquisition of potential nutrients is regulated may help develop improved approaches to cancer therapy.
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Affiliation(s)
- Craig B Thompson
- Department of Cancer Biology and Genetics, Memorial Sloan Kettering Cancer Center, New York, New York 10065
| | - Wilhelm Palm
- Department of Cancer Biology and Genetics, Memorial Sloan Kettering Cancer Center, New York, New York 10065
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284
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Ben-Sahra I, Manning BD. mTORC1 signaling and the metabolic control of cell growth. Curr Opin Cell Biol 2017; 45:72-82. [PMID: 28411448 PMCID: PMC5545101 DOI: 10.1016/j.ceb.2017.02.012] [Citation(s) in RCA: 401] [Impact Index Per Article: 57.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Revised: 02/05/2017] [Accepted: 02/17/2017] [Indexed: 01/25/2023]
Abstract
mTOR [mechanistic target of rapamycin] is a serine/threonine protein kinase that, as part of mTORC1 (mTOR complex 1), acts as an important molecular connection between nutrient signals and the metabolic processes indispensable for cell growth. While there has been pronounced interest in the upstream mechanisms regulating mTORC1, the full range of downstream molecular targets through which mTORC1 signaling stimulates cell growth is only recently emerging. It is now evident that mTORC1 promotes cell growth primarily through the activation of key anabolic processes. Through a diverse set of downstream targets, mTORC1 promotes the biosynthesis of macromolecules, including proteins, lipids, and nucleotides to build the biomass underlying cell, tissue, and organismal growth. Here, we focus on the metabolic functions of mTORC1 as they relate to the control of cell growth. As dysregulated mTORC1 underlies a variety of human diseases, including cancer, diabetes, autoimmune diseases, and neurological disorders, understanding the metabolic program downstream of mTORC1 provides insights into its role in these pathological states.
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Affiliation(s)
- Issam Ben-Sahra
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
| | - Brendan D Manning
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
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285
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Ariga M, Yoneyama Y, Fukushima T, Ishiuchi Y, Ishii T, Sato H, Hakuno F, Nedachi T, Takahashi SI. Glucose deprivation attenuates sortilin levels in skeletal muscle cells. Endocr J 2017; 64:255-268. [PMID: 27980238 DOI: 10.1507/endocrj.ej16-0319] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
In skeletal muscle, sortilin plays a predominant role in the sorting of glucose transporter 4 (Glut4), thereby controlling glucose uptake. Moreover, our previous study suggested that the sortilin expression levels are also implicated in myogenesis. Despite the importance of sortilin in skeletal muscle, however, the regulation of sortilin expression has not been completely understood. In the present study, we analyzed if the sortilin expression is regulated by glucose in C2C12 myocytes and rat skeletal muscles in vivo. Sortilin protein expression was elevated upon C2C12 cell differentiation and was further enhanced in the presence of a high concentration of glucose. The gene expression and protein degradation of sortilin were not affected by glucose. On the other hand, rapamycin partially reduced sortilin induction by a high concentration of glucose, which suggested that sortilin translation could be regulated by glucose, at least in part. We also examined if the sortilin regulation by glucose was also observed in skeletal muscles that were obtained from fed or fasted rats. Sortilin expression in both gastrocnemius and extensor digitorum longus (EDL) muscle was significantly decreased by 17-18h of starvation. On the other hand, pathological levels of high blood glucose did not alter the sortilin expression in rat skeletal muscle. Overall, the present study suggests that sortilin protein levels are reduced under hypoglycemic conditions by post-transcriptional control in skeletal muscles.
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MESH Headings
- Adaptor Proteins, Vesicular Transport/agonists
- Adaptor Proteins, Vesicular Transport/genetics
- Adaptor Proteins, Vesicular Transport/metabolism
- Animals
- Blood Glucose/analysis
- Cell Differentiation
- Cell Line
- Diabetes Mellitus, Experimental/blood
- Diabetes Mellitus, Experimental/metabolism
- Diabetes Mellitus, Experimental/pathology
- Down-Regulation/drug effects
- Fasting/metabolism
- Food Deprivation
- Glucose/metabolism
- Hindlimb
- Male
- Mechanistic Target of Rapamycin Complex 1
- Multiprotein Complexes/antagonists & inhibitors
- Multiprotein Complexes/metabolism
- Muscle Cells/cytology
- Muscle Cells/drug effects
- Muscle Cells/metabolism
- Muscle Cells/pathology
- Muscle, Skeletal/cytology
- Muscle, Skeletal/drug effects
- Muscle, Skeletal/metabolism
- Muscle, Skeletal/pathology
- Protein Kinase Inhibitors/pharmacology
- RNA, Messenger/metabolism
- Rats, Wistar
- Sirolimus/pharmacology
- TOR Serine-Threonine Kinases/antagonists & inhibitors
- TOR Serine-Threonine Kinases/metabolism
- Up-Regulation/drug effects
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Affiliation(s)
- Miyako Ariga
- Department of Animal Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
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286
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Mayers JR, Torrence ME, Danai LV, Papagiannakopoulos T, Davidson SM, Bauer MR, Lau AN, Ji BW, Dixit PD, Hosios AM, Muir A, Chin CR, Freinkman E, Jacks T, Wolpin BM, Vitkup D, Vander Heiden MG. Tissue of origin dictates branched-chain amino acid metabolism in mutant Kras-driven cancers. Science 2017; 353:1161-5. [PMID: 27609895 DOI: 10.1126/science.aaf5171] [Citation(s) in RCA: 409] [Impact Index Per Article: 58.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2016] [Accepted: 07/29/2016] [Indexed: 12/18/2022]
Abstract
Tumor genetics guides patient selection for many new therapies, and cell culture studies have demonstrated that specific mutations can promote metabolic phenotypes. However, whether tissue context defines cancer dependence on specific metabolic pathways is unknown. Kras activation and Trp53 deletion in the pancreas or the lung result in pancreatic ductal adenocarinoma (PDAC) or non-small cell lung carcinoma (NSCLC), respectively, but despite the same initiating events, these tumors use branched-chain amino acids (BCAAs) differently. NSCLC tumors incorporate free BCAAs into tissue protein and use BCAAs as a nitrogen source, whereas PDAC tumors have decreased BCAA uptake. These differences are reflected in expression levels of BCAA catabolic enzymes in both mice and humans. Loss of Bcat1 and Bcat2, the enzymes responsible for BCAA use, impairs NSCLC tumor formation, but these enzymes are not required for PDAC tumor formation, arguing that tissue of origin is an important determinant of how cancers satisfy their metabolic requirements.
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Affiliation(s)
- Jared R Mayers
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. These authors contributed equally to this work
| | - Margaret E Torrence
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. These authors contributed equally to this work
| | - Laura V Danai
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Thales Papagiannakopoulos
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Shawn M Davidson
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Matthew R Bauer
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Allison N Lau
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Brian W Ji
- Center for Computational Biology and Bioinformatics and Department of Systems Biology, Columbia University, New York, NY 10027, USA
| | - Purushottam D Dixit
- Center for Computational Biology and Bioinformatics and Department of Systems Biology, Columbia University, New York, NY 10027, USA
| | - Aaron M Hosios
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Alexander Muir
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Christopher R Chin
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Elizaveta Freinkman
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. Whitehead Institute for Biomedical Research, Nine Cambridge Center, Cambridge, MA 02142, USA. Broad Institute, Seven Cambridge Center, Cambridge, MA 02142, USA. Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Tyler Jacks
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | | | - Dennis Vitkup
- Center for Computational Biology and Bioinformatics and Department of Systems Biology, Columbia University, New York, NY 10027, USA
| | - Matthew G Vander Heiden
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. Broad Institute, Seven Cambridge Center, Cambridge, MA 02142, USA. Dana-Farber Cancer Institute, Boston, MA 02115, USA.
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287
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Ruf S, Heberle AM, Langelaar-Makkinje M, Gelino S, Wilkinson D, Gerbeth C, Schwarz JJ, Holzwarth B, Warscheid B, Meisinger C, van Vugt MATM, Baumeister R, Hansen M, Thedieck K. PLK1 (polo like kinase 1) inhibits MTOR complex 1 and promotes autophagy. Autophagy 2017; 13:486-505. [PMID: 28102733 PMCID: PMC5361591 DOI: 10.1080/15548627.2016.1263781] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Revised: 11/09/2016] [Accepted: 11/16/2016] [Indexed: 02/08/2023] Open
Abstract
Mechanistic target of rapamycin complex 1 (MTORC1) and polo like kinase 1 (PLK1) are major drivers of cancer cell growth and proliferation, and inhibitors of both protein kinases are currently being investigated in clinical studies. To date, MTORC1's and PLK1's functions are mostly studied separately, and reports on their mutual crosstalk are scarce. Here, we identify PLK1 as a physical MTORC1 interactor in human cancer cells. PLK1 inhibition enhances MTORC1 activity under nutrient sufficiency and in starved cells, and PLK1 directly phosphorylates the MTORC1 component RPTOR/RAPTOR in vitro. PLK1 and MTORC1 reside together at lysosomes, the subcellular site where MTORC1 is active. Consistent with an inhibitory role of PLK1 toward MTORC1, PLK1 overexpression inhibits lysosomal association of the PLK1-MTORC1 complex, whereas PLK1 inhibition promotes lysosomal localization of MTOR. PLK1-MTORC1 binding is enhanced by amino acid starvation, a condition known to increase autophagy. MTORC1 inhibition is an important step in autophagy activation. Consistently, PLK1 inhibition mitigates autophagy in cancer cells both under nutrient starvation and sufficiency, and a role of PLK1 in autophagy is also observed in the invertebrate model organism Caenorhabditis elegans. In summary, PLK1 inhibits MTORC1 and thereby positively contributes to autophagy. Since autophagy is increasingly recognized to contribute to tumor cell survival and growth, we propose that cautious monitoring of MTORC1 and autophagy readouts in clinical trials with PLK1 inhibitors is needed to develop strategies for optimized (combinatorial) cancer therapies targeting MTORC1, PLK1, and autophagy.
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Affiliation(s)
- Stefanie Ruf
- Department of Bioinformatics and Molecular Genetics, Faculty of Biology, University of Freiburg, Freiburg, Germany
- Department of Pediatrics, Center for Liver, Digestive and Metabolic Diseases, University of Groningen, University Medical Center Groningen, AV Groningen, The Netherlands
- BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
- Research Training Group (RTG) 1104, University of Freiburg, Freiburg, Germany
| | - Alexander Martin Heberle
- Department of Pediatrics, Center for Liver, Digestive and Metabolic Diseases, University of Groningen, University Medical Center Groningen, AV Groningen, The Netherlands
| | - Miriam Langelaar-Makkinje
- Department of Pediatrics, Center for Liver, Digestive and Metabolic Diseases, University of Groningen, University Medical Center Groningen, AV Groningen, The Netherlands
| | - Sara Gelino
- Program of Development, Aging and Regeneration, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
- Graduate School of Biomedical Sciences, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Deepti Wilkinson
- Program of Development, Aging and Regeneration, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Carolin Gerbeth
- BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
- ZBMZ Centre for Biochemistry and Molecular Cell Research (Faculty of Medicine), University of Freiburg, Freiburg, Germany
- Institute of Biochemistry and Molecular Biology (Faculty of Medicine), University of Freiburg, Freiburg, Germany
| | - Jennifer Jasmin Schwarz
- Department of Biochemistry and Functional Proteomics, Faculty of Biology, University of Freiburg, Freiburg, Germany
- Spemann Graduate School of Biology and Medicine (SGBM), University of Freiburg, Freiburg, Germany
| | - Birgit Holzwarth
- Department of Bioinformatics and Molecular Genetics, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Bettina Warscheid
- BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
- Department of Biochemistry and Functional Proteomics, Faculty of Biology, University of Freiburg, Freiburg, Germany
- Spemann Graduate School of Biology and Medicine (SGBM), University of Freiburg, Freiburg, Germany
| | - Chris Meisinger
- BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
- ZBMZ Centre for Biochemistry and Molecular Cell Research (Faculty of Medicine), University of Freiburg, Freiburg, Germany
- Institute of Biochemistry and Molecular Biology (Faculty of Medicine), University of Freiburg, Freiburg, Germany
| | - Marcel A. T. M. van Vugt
- Department of Medical Oncology, Cancer Research Center Groningen, University of Groningen, University Medical Center Groningen, GZ Groningen, The Netherlands
| | - Ralf Baumeister
- Department of Bioinformatics and Molecular Genetics, Faculty of Biology, University of Freiburg, Freiburg, Germany
- BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
- Research Training Group (RTG) 1104, University of Freiburg, Freiburg, Germany
- ZBMZ Centre for Biochemistry and Molecular Cell Research (Faculty of Medicine), University of Freiburg, Freiburg, Germany
- Spemann Graduate School of Biology and Medicine (SGBM), University of Freiburg, Freiburg, Germany
| | - Malene Hansen
- Program of Development, Aging and Regeneration, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Kathrin Thedieck
- Department of Pediatrics, Center for Liver, Digestive and Metabolic Diseases, University of Groningen, University Medical Center Groningen, AV Groningen, The Netherlands
- Department for Neuroscience, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
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288
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Abstract
Reliance on glutamine has long been considered a hallmark of cancer cell metabolism. However, some recent studies have challenged this notion in vivo, prompting a need for further clarifications on the role of glutamine metabolism in cancer. We find that there is ample evidence of an essential role for glutamine in tumors and that a variety of factors, including tissue type, the underlying cancer genetics, the tumor microenvironment and other variables such as diet and host physiology collectively influence the role of glutamine in cancer. Thus the requirements for glutamine in cancer are overall highly heterogeneous. In this review, we discuss the implications both for basic science and for targeting glutamine metabolism in cancer therapy.
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Affiliation(s)
- Ahmad A Cluntun
- Graduate Field of Biochemistry, Molecular & Cell Biology, Cornell University, Ithaca, NY, USA; King Abdullah International Medical Research Center (KAIMRC), Riyadh, Saudi Arabia
| | - Michael J Lukey
- Department of Molecular Medicine, Cornell University, Ithaca, NY 14853, USA
| | - Richard A Cerione
- Department of Molecular Medicine, Cornell University, Ithaca, NY 14853, USA; Department of Chemistry and Chemical Biology, Cornell University, Ithaca NY 14853, USA
| | - Jason W Locasale
- Department of Pharmacology and Cancer Biology, Duke Cancer Institute, Duke Molecular Physiology Institute, Duke University School of Medicine, Durham, NC, USA
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289
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Parks SK, Cormerais Y, Pouysségur J. Hypoxia and cellular metabolism in tumour pathophysiology. J Physiol 2017; 595:2439-2450. [PMID: 28074546 DOI: 10.1113/jp273309] [Citation(s) in RCA: 95] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 12/01/2016] [Indexed: 12/17/2022] Open
Abstract
Cancer cells are optimised for growth and survival via an ability to outcompete normal cells in their microenvironment. Many of these advantageous cellular adaptations are promoted by the pathophysiological hypoxia that arises in solid tumours due to incomplete vascularisation. Tumour cells are thus faced with the challenge of an increased need for nutrients to support the drive for proliferation in the face of a diminished extracellular supply. Among the many modifications occurring in tumour cells, hypoxia inducible factors (HIFs) act as essential drivers of key pro-survival pathways via the promotion of numerous membrane and cytosolic proteins. Here we focus our attention on two areas: the role of amino acid uptake and the handling of metabolic acid (CO2 /H+ ) production. We provide evidence for a number of hypoxia-induced proteins that promote cellular anabolism and regulation of metabolic acid-base levels in tumour cells including amino-acid transporters (LAT1), monocarboxylate transporters, and acid-base regulating carbonic anhydrases (CAs) and bicarbonate transporters (NBCs). Emphasis is placed on current work manipulating multiple CA isoforms and NBCs, which is at an interesting crossroads of gas physiology as they are regulated by hypoxia to contribute to the cellular handling of CO2 and pHi regulation. Our research combined with others indicates that targeting of HIF-regulated membrane proteins in tumour cells will provide promising future anti-cancer therapeutic approaches and we suggest strategies that could be potentially used to enhance these tactics.
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Affiliation(s)
- Scott K Parks
- Medical Biology Department, Centre Scientifique de Monaco, 8 Quai Antoine 1er, MC-98000, Monaco, Principality of Monaco
| | - Yann Cormerais
- Medical Biology Department, Centre Scientifique de Monaco, 8 Quai Antoine 1er, MC-98000, Monaco, Principality of Monaco
| | - Jacques Pouysségur
- Medical Biology Department, Centre Scientifique de Monaco, 8 Quai Antoine 1er, MC-98000, Monaco, Principality of Monaco.,Institute for Research on Cancer and Aging (IRCAN), CNRS, INSERM, Centre A. Lacassagne, University of Nice-Sophia Antipolis, Nice, France
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290
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Resistance to mTORC1 Inhibitors in Cancer Therapy: From Kinase Mutations to Intratumoral Heterogeneity of Kinase Activity. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:1726078. [PMID: 28280521 PMCID: PMC5322438 DOI: 10.1155/2017/1726078] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 01/22/2017] [Indexed: 01/19/2023]
Abstract
Targeting mTORC1 has been thoroughly explored in cancer therapy. Following encouraging preclinical studies, mTORC1 inhibitors however failed to provide substantial benefits in cancer patients. Several resistance mechanisms have been identified including mutations of mTOR and activation of alternate proliferation pathways. Moreover, emerging evidence discloses intratumoral heterogeneity of mTORC1 activity that further contributes to a reduced anticancer efficacy of mTORC1 inhibitors. Genetic heterogeneity as well as heterogeneous conditions of the tumor environment such as hypoxia profoundly modifies mTORC1 activity in tumors and hence influences the response of tumors to mTORC1 inhibitors. Intriguingly, the heterogeneity of mTORC1 activity also occurs towards its substrates at the single cell level, as mutually exclusive pattern of activation of mTORC1 downstream effectors has been reported in tumors. After briefly describing mTORC1 biology and the use of mTORC1 inhibitors in patients, this review will give an overview on concepts of resistance to mTORC1 inhibition in cancer with a particular focus on intratumoral heterogeneity of mTORC1 activity.
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291
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Villar VH, Nguyen TL, Delcroix V, Terés S, Bouchecareilh M, Salin B, Bodineau C, Vacher P, Priault M, Soubeyran P, Durán RV. mTORC1 inhibition in cancer cells protects from glutaminolysis-mediated apoptosis during nutrient limitation. Nat Commun 2017; 8:14124. [PMID: 28112156 PMCID: PMC5264013 DOI: 10.1038/ncomms14124] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 12/01/2016] [Indexed: 12/16/2022] Open
Abstract
A master coordinator of cell growth, mTORC1 is activated by different metabolic inputs, particularly the metabolism of glutamine (glutaminolysis), to control a vast range of cellular processes, including autophagy. As a well-recognized tumour promoter, inhibitors of mTORC1 such as rapamycin have been approved as anti-cancer agents, but their overall outcome in patients is rather poor. Here we show that mTORC1 also presents tumour suppressor features in conditions of nutrient restrictions. Thus, the activation of mTORC1 by glutaminolysis during nutritional imbalance inhibits autophagy and induces apoptosis in cancer cells. Importantly, rapamycin treatment reactivates autophagy and prevents the mTORC1-mediated apoptosis. We also observe that the ability of mTORC1 to activate apoptosis is mediated by the adaptor protein p62. Thus, the mTORC1-mediated upregulation of p62 during nutrient imbalance induces the binding of p62 to caspase 8 and the subsequent activation of the caspase pathway. Our data highlight the role of autophagy as a survival mechanism upon rapamycin treatment.
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Affiliation(s)
- Victor H. Villar
- Institut Européen de Chimie et Biologie, INSERM U1218, Université de Bordeaux, 2 Rue Robert Escarpit, Pessac 33607, France
| | - Tra Ly Nguyen
- Institut Européen de Chimie et Biologie, INSERM U1218, Université de Bordeaux, 2 Rue Robert Escarpit, Pessac 33607, France
| | - Vanessa Delcroix
- Institut Bergonié, INSERM U1218, 229 Cours de l'Argonne, Bordeaux 33076, France
| | - Silvia Terés
- Institut Européen de Chimie et Biologie, INSERM U1218, Université de Bordeaux, 2 Rue Robert Escarpit, Pessac 33607, France
| | - Marion Bouchecareilh
- Institut de Biochimie et Génétique Cellulaires, CNRS UMR 5095, Université de Bordeaux, 1 Rue Camille Saint-Saëns, Bordeaux 33077, France
| | - Bénédicte Salin
- Institut de Biochimie et Génétique Cellulaires, CNRS UMR 5095, Université de Bordeaux, 1 Rue Camille Saint-Saëns, Bordeaux 33077, France
| | - Clément Bodineau
- Institut Européen de Chimie et Biologie, INSERM U1218, Université de Bordeaux, 2 Rue Robert Escarpit, Pessac 33607, France
| | - Pierre Vacher
- Institut Bergonié, INSERM U1218, 229 Cours de l'Argonne, Bordeaux 33076, France
| | - Muriel Priault
- Institut de Biochimie et Génétique Cellulaires, CNRS UMR 5095, Université de Bordeaux, 1 Rue Camille Saint-Saëns, Bordeaux 33077, France
| | - Pierre Soubeyran
- Institut Bergonié, INSERM U1218, 229 Cours de l'Argonne, Bordeaux 33076, France
| | - Raúl V. Durán
- Institut Européen de Chimie et Biologie, INSERM U1218, Université de Bordeaux, 2 Rue Robert Escarpit, Pessac 33607, France
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292
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Starved epithelial cells uptake extracellular matrix for survival. Nat Commun 2017; 8:13989. [PMID: 28071763 PMCID: PMC5234072 DOI: 10.1038/ncomms13989] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Accepted: 11/17/2016] [Indexed: 01/12/2023] Open
Abstract
Extracellular matrix adhesion is required for normal epithelial cell survival, nutrient uptake and metabolism. This requirement can be overcome by oncogene activation. Interestingly, inhibition of PI3K/mTOR leads to apoptosis of matrix-detached, but not matrix-attached cancer cells, suggesting that matrix-attached cells use alternate mechanisms to maintain nutrient supplies. Here we demonstrate that under conditions of dietary restriction or growth factor starvation, where PI3K/mTOR signalling is decreased, matrix-attached human mammary epithelial cells upregulate and internalize β4-integrin along with its matrix substrate, laminin. Endocytosed laminin localizes to lysosomes, results in increased intracellular levels of essential amino acids and enhanced mTORC1 signalling, preventing cell death. Moreover, we show that starved human fibroblasts secrete matrix proteins that maintain the growth of starved mammary epithelial cells contingent upon epithelial cell β4-integrin expression. Our study identifies a crosstalk between stromal fibroblasts and epithelial cells under starvation that could be exploited therapeutically to target tumours resistant to PI3K/mTOR inhibition. Inhibition of PI3K/mTOR, which mimics nutrient starvation, causes death of detached but not matrix-attached cancer cells. Here the authors show that nutrient restriction of epithelial cells causes uptake of the matrix protein laminin, which results in increased intracellular amino acids and enhanced mTORC1 signalling.
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293
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Halbrook CJ, Lyssiotis CA. Employing Metabolism to Improve the Diagnosis and Treatment of Pancreatic Cancer. Cancer Cell 2017; 31:5-19. [PMID: 28073003 DOI: 10.1016/j.ccell.2016.12.006] [Citation(s) in RCA: 254] [Impact Index Per Article: 36.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 10/03/2016] [Accepted: 12/14/2016] [Indexed: 02/07/2023]
Abstract
Pancreatic ductal adenocarcinoma is on pace to become the second leading cause of cancer-related death. The high mortality rate results from a lack of methods for early detection and the inability to successfully treat patients once diagnosed. Pancreatic cancer cells have extensively reprogrammed metabolism, which is driven by oncogene-mediated cell-autonomous pathways, the unique physiology of the tumor microenvironment, and interactions with non-cancer cells. In this review, we discuss how recent efforts delineating rewired metabolic networks in pancreatic cancer have revealed new in-roads to develop detection and treatment strategies for this dreadful disease.
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Affiliation(s)
- Christopher J Halbrook
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Costas A Lyssiotis
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA; Department of Internal Medicine, Division of Gastroenterology, University of Michigan, Ann Arbor, MI 48109, USA.
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294
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Recouvreux MV, Commisso C. Macropinocytosis: A Metabolic Adaptation to Nutrient Stress in Cancer. Front Endocrinol (Lausanne) 2017; 8:261. [PMID: 29085336 PMCID: PMC5649207 DOI: 10.3389/fendo.2017.00261] [Citation(s) in RCA: 150] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2017] [Accepted: 09/20/2017] [Indexed: 12/28/2022] Open
Abstract
Oncogenic mutations, such as Ras mutations, drive not only enhanced proliferation but also the metabolic adaptations that confer to cancer cells the ability to sustain cell growth in a harsh tumor microenvironment. These adaptations might represent metabolic vulnerabilities that can be exploited to develop novel and more efficient cancer therapies. Macropinocytosis is an evolutionarily conserved endocytic pathway that permits the internalization of extracellular fluid via large endocytic vesicles known as macropinosomes. Recently, macropinocytosis has been determined to function as a nutrient-scavenging pathway in Ras-driven cancer cells. Macropinocytic uptake of extracellular proteins, and their further degradation within endolysosomes, provides the much-needed amino acids that fuel cancer cell metabolism and tumor growth. Here, we review the molecular mechanisms that govern the process of macropinocytosis, as well as discuss recent work that provides evidence of the important role of macropinocytosis as a nutrient supply pathway in cancer cells.
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Affiliation(s)
- Maria Victoria Recouvreux
- Tumor Initiation and Maintenance Program, NCI-Designated Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, United States
| | - Cosimo Commisso
- Tumor Initiation and Maintenance Program, NCI-Designated Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, United States
- *Correspondence: Cosimo Commisso,
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295
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Direct evidence for cancer-cell-autonomous extracellular protein catabolism in pancreatic tumors. Nat Med 2016; 23:235-241. [PMID: 28024083 DOI: 10.1038/nm.4256] [Citation(s) in RCA: 249] [Impact Index Per Article: 31.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 11/10/2016] [Indexed: 12/14/2022]
Abstract
Mammalian tissues rely on a variety of nutrients to support their physiological functions. It is known that altered metabolism is involved in the pathogenesis of cancer, but which nutrients support the inappropriate growth of intact malignant tumors is incompletely understood. Amino acids are essential nutrients for many cancer cells that can be obtained through the scavenging and catabolism of extracellular protein via macropinocytosis. In particular, macropinocytosis can be a nutrient source for pancreatic cancer cells, but it is not fully understood how the tumor environment influences metabolic phenotypes and whether macropinocytosis supports the maintenance of amino acid levels within pancreatic tumors. Here we utilize miniaturized plasma exchange to deliver labeled albumin to tissues in live mice, and we demonstrate that breakdown of albumin contributes to the supply of free amino acids in pancreatic tumors. We also deliver albumin directly into tumors using an implantable microdevice, which was adapted and modified from ref. 9. Following implantation, we directly observe protein catabolism and macropinocytosis in situ by pancreatic cancer cells, but not by adjacent, non-cancerous pancreatic tissue. In addition, we find that intratumoral inhibition of macropinocytosis decreases amino acid levels. Taken together, these data suggest that pancreatic cancer cells consume extracellular protein, including albumin, and that this consumption serves as an important source of amino acids for pancreatic cancer cells in vivo.
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296
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Driscoll DR, Karim SA, Sano M, Gay DM, Jacob W, Yu J, Mizukami Y, Gopinathan A, Jodrell DI, Evans TRJ, Bardeesy N, Hall MN, Quattrochi BJ, Klimstra DS, Barry ST, Sansom OJ, Lewis BC, Morton JP. mTORC2 Signaling Drives the Development and Progression of Pancreatic Cancer. Cancer Res 2016; 76:6911-6923. [PMID: 27758884 PMCID: PMC5135633 DOI: 10.1158/0008-5472.can-16-0810] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Revised: 08/31/2016] [Accepted: 09/15/2016] [Indexed: 12/13/2022]
Abstract
mTOR signaling controls several critical cellular functions and is deregulated in many cancers, including pancreatic cancer. To date, most efforts have focused on inhibiting the mTORC1 complex. However, clinical trials of mTORC1 inhibitors in pancreatic cancer have failed, raising questions about this therapeutic approach. We employed a genetic approach to delete the obligate mTORC2 subunit Rictor and identified the critical times during which tumorigenesis requires mTORC2 signaling. Rictor deletion resulted in profoundly delayed tumorigenesis. Whereas previous studies showed most pancreatic tumors were insensitive to rapamycin, treatment with a dual mTORC1/2 inhibitor strongly suppressed tumorigenesis. In late-stage tumor-bearing mice, combined mTORC1/2 and PI3K inhibition significantly increased survival. Thus, targeting mTOR may be a potential therapeutic strategy in pancreatic cancer. Cancer Res; 76(23); 6911-23. ©2016 AACR.
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Affiliation(s)
- David R Driscoll
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts
| | | | - Makoto Sano
- Department of Pathology and Microbiology, Nihon University School of Medicine, Tokyo, Japan
| | - David M Gay
- CRUK Beatson Institute, Glasgow, United Kingdom
| | - Wright Jacob
- Institute of Cancer Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Jun Yu
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Yusuke Mizukami
- Cancer Center, Massachusetts General Hospital, Boston, Massachusetts
| | | | | | - T R Jeffry Evans
- CRUK Beatson Institute, Glasgow, United Kingdom
- Institute of Cancer Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Nabeel Bardeesy
- Cancer Center, Massachusetts General Hospital, Boston, Massachusetts
| | | | - Brian J Quattrochi
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts
| | - David S Klimstra
- Department of Pathology, Memorial Sloan-Kettering Cancer Center, New York, New York
| | | | - Owen J Sansom
- CRUK Beatson Institute, Glasgow, United Kingdom.
- Institute of Cancer Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Brian C Lewis
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts.
- Cancer Center, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Jennifer P Morton
- CRUK Beatson Institute, Glasgow, United Kingdom
- Institute of Cancer Sciences, University of Glasgow, Glasgow, United Kingdom
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297
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Park JK, Peng H, Katsnelson J, Yang W, Kaplan N, Dong Y, Rappoport JZ, He C, Lavker RM. MicroRNAs-103/107 coordinately regulate macropinocytosis and autophagy. J Cell Biol 2016; 215:667-685. [PMID: 27872138 PMCID: PMC5146999 DOI: 10.1083/jcb.201604032] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 08/29/2016] [Accepted: 11/01/2016] [Indexed: 11/28/2022] Open
Abstract
The miR-103/107 family is preferentially expressed in the stem cell–enriched limbal epithelium and regulates multiple characteristics associated with stem cells. Park et al. show that miR-103/107 also contribute to limbal epithelial homeostasis by suppressing macropinocytosis and preserving end-stage autophagy. Macropinocytosis, by which cells ingest large amounts of fluid, and autophagy, the lysosome-based catabolic process, involve vesicular biogenesis (early stage) and turnover (end stage). Much is known about early-stage events; however, our understanding of how the end stages of these processes are governed is incomplete. Here we demonstrate that the microRNA-103/107(miR-103/107) family, which is preferentially expressed in the stem cell–enriched limbal epithelium, coordinately regulates aspects of both these activities. Loss of miR-103/107 causes dysregulation of macropinocytosis with the formation of large vacuoles, primarily through up-regulation of Src, Ras, and Ankfy1. Vacuole accumulation is not a malfunction of early-stage autophagy; rather, miR-103/107 ensure proper end-stage autophagy by regulating diacylglycerol/protein kinase C and cyclin-dependent kinase 5 signaling, which enables dynamin to function in vacuole clearance. Our findings unveil a key biological function for miR-103/107 in coordinately suppressing macropinocytosis and preserving end-stage autophagy, thereby contributing to maintenance of a stem cell–enriched epithelium.
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Affiliation(s)
- Jong Kook Park
- Department of Dermatology, Northwestern University, Chicago, IL 60611
| | - Han Peng
- Department of Dermatology, Northwestern University, Chicago, IL 60611
| | | | - Wending Yang
- Department of Dermatology, Northwestern University, Chicago, IL 60611
| | - Nihal Kaplan
- Department of Dermatology, Northwestern University, Chicago, IL 60611
| | - Ying Dong
- Department of Dermatology, Northwestern University, Chicago, IL 60611.,Department of Ophthalmology, The First Affiliated Hospital, Chinese PLA General Hospital, Beijing 100048, China
| | - Joshua Z Rappoport
- Center for Advanced Microscopy and Nikon Imaging Center, Northwestern University, Chicago, IL 60611
| | - CongCong He
- Department of Cell and Molecular Biology, Northwestern University, Chicago, IL 60611
| | - Robert M Lavker
- Department of Dermatology, Northwestern University, Chicago, IL 60611
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298
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May glutamine addiction drive the delivery of antitumor cisplatin-based Pt(IV) prodrugs? J Inorg Biochem 2016; 167:27-35. [PMID: 27898344 DOI: 10.1016/j.jinorgbio.2016.11.024] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 11/09/2016] [Accepted: 11/16/2016] [Indexed: 12/11/2022]
Abstract
A small series of Pt(IV) prodrugs containing Gln-like (Gln=glutamine) axial ligands has been designed with the aim to take advantage of the increased demand of Gln showed by some cancer cells (glutamine addiction). In complex 4 the Gln, linked through the α-carboxylic group is recognized by the Gln transporters, in particular by the solute carrier transporter SLC1A5. All compounds showed cellular accumulation, as well as antiproliferative activity, related to their lipophilicity, as already demonstrated for the majority of Pt(IV) prodrugs, that enter cells mainly by passive diffusion. On the contrary, when the Gln concentration in cell medium is near or lower to the physiological value, complex 4 acts as a Trojan horse: it enters SLC1A5-overexpressing cells, where, upon reduction, it releases the active metabolite cisplatin and the Gln-containing ligand, thus preventing any possible extrusion by the L-type amino acid transporter LAT1. This selective mechanism could decrease off-target accumulation of 4 and, consequently, Pt-associated side-effects.
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299
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Kim SM, Roy SG, Chen B, Nguyen TM, McMonigle RJ, McCracken AN, Zhang Y, Kofuji S, Hou J, Selwan E, Finicle BT, Nguyen TT, Ravi A, Ramirez MU, Wiher T, Guenther GG, Kono M, Sasaki AT, Weisman LS, Potma EO, Tromberg BJ, Edwards RA, Hanessian S, Edinger AL. Targeting cancer metabolism by simultaneously disrupting parallel nutrient access pathways. J Clin Invest 2016; 126:4088-4102. [PMID: 27669461 PMCID: PMC5096903 DOI: 10.1172/jci87148] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 08/16/2016] [Indexed: 12/23/2022] Open
Abstract
Oncogenic mutations drive anabolic metabolism, creating a dependency on nutrient influx through transporters, receptors, and macropinocytosis. While sphingolipids suppress tumor growth by downregulating nutrient transporters, macropinocytosis and autophagy still provide cancer cells with fuel. Therapeutics that simultaneously disrupt these parallel nutrient access pathways have potential as powerful starvation agents. Here, we describe a water-soluble, orally bioavailable synthetic sphingolipid, SH-BC-893, that triggers nutrient transporter internalization and also blocks lysosome-dependent nutrient generation pathways. SH-BC-893 activated protein phosphatase 2A (PP2A), leading to mislocalization of the lipid kinase PIKfyve. The concomitant mislocalization of the PIKfyve product PI(3,5)P2 triggered cytosolic vacuolation and blocked lysosomal fusion reactions essential for LDL, autophagosome, and macropinosome degradation. By simultaneously limiting access to both extracellular and intracellular nutrients, SH-BC-893 selectively killed cells expressing an activated form of the anabolic oncogene Ras in vitro and in vivo. However, slower-growing, autochthonous PTEN-deficient prostate tumors that did not exhibit a classic Warburg phenotype were equally sensitive. Remarkably, normal proliferative tissues were unaffected by doses of SH-BC-893 that profoundly inhibited tumor growth. These studies demonstrate that simultaneously blocking parallel nutrient access pathways with sphingolipid-based drugs is broadly effective and cancer selective, suggesting a potential strategy for overcoming the resistance conferred by tumor heterogeneity.
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Affiliation(s)
- Seong M. Kim
- Department of Developmental and Cell Biology, University of California Irvine (UCI), Irvine, California, USA
| | - Saurabh G. Roy
- Department of Developmental and Cell Biology, University of California Irvine (UCI), Irvine, California, USA
| | - Bin Chen
- Department of Chemistry, Université de Montréal, Montréal, Québec, Canada
| | - Tiffany M. Nguyen
- Department of Developmental and Cell Biology, University of California Irvine (UCI), Irvine, California, USA
| | - Ryan J. McMonigle
- Department of Developmental and Cell Biology, University of California Irvine (UCI), Irvine, California, USA
| | - Alison N. McCracken
- Department of Developmental and Cell Biology, University of California Irvine (UCI), Irvine, California, USA
| | - Yanling Zhang
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Satoshi Kofuji
- Departments of Internal Medicine, Neurosurgery, and Cancer Biology, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Jue Hou
- Department of Biomedical Engineering, UCI, Irvine, California, USA
| | - Elizabeth Selwan
- Department of Developmental and Cell Biology, University of California Irvine (UCI), Irvine, California, USA
| | - Brendan T. Finicle
- Department of Developmental and Cell Biology, University of California Irvine (UCI), Irvine, California, USA
| | - Tricia T. Nguyen
- Department of Developmental and Cell Biology, University of California Irvine (UCI), Irvine, California, USA
| | - Archna Ravi
- Department of Developmental and Cell Biology, University of California Irvine (UCI), Irvine, California, USA
| | - Manuel U. Ramirez
- Department of Developmental and Cell Biology, University of California Irvine (UCI), Irvine, California, USA
| | - Tim Wiher
- Department of Developmental and Cell Biology, University of California Irvine (UCI), Irvine, California, USA
| | - Garret G. Guenther
- Department of Developmental and Cell Biology, University of California Irvine (UCI), Irvine, California, USA
| | - Mari Kono
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), Bethesda, Maryland, USA
| | - Atsuo T. Sasaki
- Departments of Internal Medicine, Neurosurgery, and Cancer Biology, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Lois S. Weisman
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Eric O. Potma
- Department of Biomedical Engineering, UCI, Irvine, California, USA
| | | | - Robert A. Edwards
- Department of Pathology, University of California Irvine School of Medicine, Irvine, California, USA
| | - Stephen Hanessian
- Department of Chemistry, Université de Montréal, Montréal, Québec, Canada
- Department of Pharmaceutical Sciences, UCI, Irvine, California, USA
| | - Aimee L. Edinger
- Department of Developmental and Cell Biology, University of California Irvine (UCI), Irvine, California, USA
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300
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Pacitto R, Gaeta I, Swanson JA, Yoshida S. CXCL12-induced macropinocytosis modulates two distinct pathways to activate mTORC1 in macrophages. J Leukoc Biol 2016; 101:683-692. [PMID: 28250113 DOI: 10.1189/jlb.2a0316-141rr] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2016] [Revised: 09/16/2016] [Accepted: 09/24/2016] [Indexed: 12/14/2022] Open
Abstract
Although growth factors and chemokines elicit different overall effects on cells-growth and chemotaxis, respectively-and activate distinct classes of cell-surface receptors, nonetheless, they trigger similar cellular activities and signaling pathways. The growth factor M-CSF and the chemokine CXCL12 both stimulate the endocytic process of macropinocytosis, and both activate the mechanistic target of rapamycin complex 1 (mTORC1), a protein complex that regulates cell metabolism. Recent studies of signaling by M-CSF in macrophages identified a role for macropinocytosis in the activation of mTORC1, in which delivery of extracellular amino acids into lysosomes via macropinocytosis was required for activation of mTORC1. Here, we analyzed the regulation of macropinosome (MP) formation in response to CXCL12 and identified 2 roles for macropinocytosis in the activation of mTORC1. Within 5 min of adding CXCL12, murine macrophages increased ruffling, macropinocytosis and amino acid-dependent activation of mTORC1. Inhibitors of macropinocytosis blocked activation of mTORC1, and various isoform-specific inhibitors of type 1 PI3K and protein kinase C (PKC) showed similar patterns of inhibition of macropinocytosis and mTORC1 activity. However, unlike the response to M-CSF, Akt phosphorylation (pAkt) in response to CXCL12 required the actin cytoskeleton and the formation of macropinocytic cups. Quantitative fluorescence microscopy showed that phosphatidylinositol (3,4,5)-trisphosphate (PIP3), a product of PI3K and an upstream activator of Akt, localized to macropinocytic cups and that pAkt occurred primarily in cups. These results indicate that CXCL12 activates mTORC1 via 2 mechanisms: 1) that the macropinocytic cup localizes Akt signaling and 2) that MPs convey extracellular nutrients to lysosomes.
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Affiliation(s)
- Regina Pacitto
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Isabella Gaeta
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Joel A Swanson
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Sei Yoshida
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
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