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Abstract
In Slavic folklore, Koschei the Immortal was bony, thin and lean. Was his condition caused by severe calorie restriction (CR)? CR deactivates the target of rapamycin pathway and slows down aging. But the life-extending effect of severe CR is limited by starvation. What if Koschei's anti-aging formula included rapamycin? And was rapamycin (or another rapalog) combined with commonly available drugs such as metformin, aspirin, propranolol, angiotensin II receptor blockers and angiotensin-converting enzyme inhibitors.
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Affiliation(s)
- M V Blagosklonny
- Department of Cell Stress Biology, Roswell Park Cancer Institute, BLSC, L3-312, Elm and Carlton Streets, Buffalo, NY, USA
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2
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Galluzzi L, Bravo-San Pedro JM, Vitale I, Aaronson SA, Abrams JM, Adam D, Alnemri ES, Altucci L, Andrews D, Annicchiarico-Petruzzelli M, Baehrecke EH, Bazan NG, Bertrand MJ, Bianchi K, Blagosklonny MV, Blomgren K, Borner C, Bredesen DE, Brenner C, Campanella M, Candi E, Cecconi F, Chan FK, Chandel NS, Cheng EH, Chipuk JE, Cidlowski JA, Ciechanover A, Dawson TM, Dawson VL, De Laurenzi V, De Maria R, Debatin KM, Di Daniele N, Dixit VM, Dynlacht BD, El-Deiry WS, Fimia GM, Flavell RA, Fulda S, Garrido C, Gougeon ML, Green DR, Gronemeyer H, Hajnoczky G, Hardwick JM, Hengartner MO, Ichijo H, Joseph B, Jost PJ, Kaufmann T, Kepp O, Klionsky DJ, Knight RA, Kumar S, Lemasters JJ, Levine B, Linkermann A, Lipton SA, Lockshin RA, López-Otín C, Lugli E, Madeo F, Malorni W, Marine JC, Martin SJ, Martinou JC, Medema JP, Meier P, Melino S, Mizushima N, Moll U, Muñoz-Pinedo C, Nuñez G, Oberst A, Panaretakis T, Penninger JM, Peter ME, Piacentini M, Pinton P, Prehn JH, Puthalakath H, Rabinovich GA, Ravichandran KS, Rizzuto R, Rodrigues CM, Rubinsztein DC, Rudel T, Shi Y, Simon HU, Stockwell BR, Szabadkai G, Tait SW, Tang HL, Tavernarakis N, Tsujimoto Y, Vanden Berghe T, Vandenabeele P, Villunger A, Wagner EF, Walczak H, White E, Wood WG, Yuan J, Zakeri Z, Zhivotovsky B, Melino G, Kroemer G. Essential versus accessory aspects of cell death: recommendations of the NCCD 2015. Cell Death Differ 2014; 22:58-73. [PMID: 25236395 PMCID: PMC4262782 DOI: 10.1038/cdd.2014.137] [Citation(s) in RCA: 664] [Impact Index Per Article: 66.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Accepted: 07/30/2014] [Indexed: 02/07/2023] Open
Abstract
Cells exposed to extreme physicochemical or mechanical stimuli die in an uncontrollable manner, as a result of their immediate structural breakdown. Such an unavoidable variant of cellular demise is generally referred to as ‘accidental cell death' (ACD). In most settings, however, cell death is initiated by a genetically encoded apparatus, correlating with the fact that its course can be altered by pharmacologic or genetic interventions. ‘Regulated cell death' (RCD) can occur as part of physiologic programs or can be activated once adaptive responses to perturbations of the extracellular or intracellular microenvironment fail. The biochemical phenomena that accompany RCD may be harnessed to classify it into a few subtypes, which often (but not always) exhibit stereotyped morphologic features. Nonetheless, efficiently inhibiting the processes that are commonly thought to cause RCD, such as the activation of executioner caspases in the course of apoptosis, does not exert true cytoprotective effects in the mammalian system, but simply alters the kinetics of cellular demise as it shifts its morphologic and biochemical correlates. Conversely, bona fide cytoprotection can be achieved by inhibiting the transduction of lethal signals in the early phases of the process, when adaptive responses are still operational. Thus, the mechanisms that truly execute RCD may be less understood, less inhibitable and perhaps more homogeneous than previously thought. Here, the Nomenclature Committee on Cell Death formulates a set of recommendations to help scientists and researchers to discriminate between essential and accessory aspects of cell death.
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Affiliation(s)
- L Galluzzi
- 1] Gustave Roussy Cancer Center, Villejuif, France [2] Equipe 11 labellisée par la Ligue Nationale contre le Cancer, Centre de Recherche des Cordeliers, Paris, France [3] Université Paris Descartes/Paris V, Sorbonne Paris Cité, Paris, France
| | - J M Bravo-San Pedro
- 1] Gustave Roussy Cancer Center, Villejuif, France [2] Equipe 11 labellisée par la Ligue Nationale contre le Cancer, Centre de Recherche des Cordeliers, Paris, France [3] INSERM, U1138, Gustave Roussy, Paris, France
| | - I Vitale
- Regina Elena National Cancer Institute, Rome, Italy
| | - S A Aaronson
- Department of Oncological Sciences, The Tisch Cancer Institute, Ichan School of Medicine at Mount Sinai, New York, NY, USA
| | - J M Abrams
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, TX, USA
| | - D Adam
- Institute of Immunology, Christian-Albrechts University, Kiel, Germany
| | - E S Alnemri
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - L Altucci
- Dipartimento di Biochimica, Biofisica e Patologia Generale, Seconda Università degli Studi di Napoli, Napoli, Italy
| | - D Andrews
- Department of Biochemistry and Medical Biophysics, University of Toronto, Toronto, ON, Canada
| | - M Annicchiarico-Petruzzelli
- Biochemistry Laboratory, Istituto Dermopatico dell'Immacolata - Istituto Ricovero Cura Carattere Scientifico (IDI-IRCCS), Rome, Italy
| | - E H Baehrecke
- Department of Cancer Biology, University of Massachusetts Medical School, Worcester, MA, USA
| | - N G Bazan
- Neuroscience Center of Excellence, School of Medicine, New Orleans, LA, USA
| | - M J Bertrand
- 1] VIB Inflammation Research Center, Ghent, Belgium [2] Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - K Bianchi
- 1] Barts Cancer Institute, Cancer Research UK Centre of Excellence, London, UK [2] Queen Mary University of London, John Vane Science Centre, London, UK
| | - M V Blagosklonny
- Department of Cell Stress Biology, Roswell Park Cancer Institute, Buffalo, NY, USA
| | - K Blomgren
- Karolinska University Hospital, Karolinska Institute, Stockholm, Sweden
| | - C Borner
- Institute of Molecular Medicine and Spemann Graduate School of Biology and Medicine, Albert-Ludwigs University, Freiburg, Germany
| | - D E Bredesen
- 1] Buck Institute for Research on Aging, Novato, CA, USA [2] Department of Neurology, University of California, San Francisco (UCSF), San Francisco, CA, USA
| | - C Brenner
- 1] INSERM, UMRS769, Châtenay Malabry, France [2] LabEx LERMIT, Châtenay Malabry, France [3] Université Paris Sud/Paris XI, Orsay, France
| | - M Campanella
- Department of Comparative Biomedical Sciences and Consortium for Mitochondrial Research, University College London (UCL), London, UK
| | - E Candi
- Department of Experimental Medicine and Surgery, University of Rome Tor Vergata, Rome, Italy
| | - F Cecconi
- 1] Laboratory of Molecular Neuroembryology, IRCCS Fondazione Santa Lucia, Rome, Italy [2] Department of Biology, University of Rome Tor Vergata; Rome, Italy [3] Unit of Cell Stress and Survival, Danish Cancer Society Research Center, Copenhagen, Denmark
| | - F K Chan
- Department of Pathology, University of Massachusetts Medical School, Worcester, MA, USA
| | - N S Chandel
- Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - E H Cheng
- Human Oncology and Pathogenesis Program and Department of Pathology, Memorial Sloan Kettering Cancer Center (MSKCC), New York, NY, USA
| | - J E Chipuk
- Department of Oncological Sciences, The Tisch Cancer Institute, Ichan School of Medicine at Mount Sinai, New York, NY, USA
| | - J A Cidlowski
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences (NIEHS), National Institute of Health (NIH), North Carolina, NC, USA
| | - A Ciechanover
- Tumor and Vascular Biology Research Center, The Rappaport Faculty of Medicine and Research Institute, Technion Israel Institute of Technology, Haifa, Israel
| | - T M Dawson
- 1] Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering (ICE), Departments of Neurology, Pharmacology and Molecular Sciences, Solomon H Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA [2] Adrienne Helis Malvin Medical Research Foundation, New Orleans, LA, USA
| | - V L Dawson
- 1] Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering (ICE), Departments of Neurology, Pharmacology and Molecular Sciences, Solomon H Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA [2] Adrienne Helis Malvin Medical Research Foundation, New Orleans, LA, USA
| | - V De Laurenzi
- Department of Experimental and Clinical Sciences, Gabriele d'Annunzio University, Chieti, Italy
| | - R De Maria
- Regina Elena National Cancer Institute, Rome, Italy
| | - K-M Debatin
- Department of Pediatrics and Adolescent Medicine, Ulm University Medical Center, Ulm, Germany
| | - N Di Daniele
- Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy
| | - V M Dixit
- Department of Physiological Chemistry, Genentech, South San Francisco, CA, USA
| | - B D Dynlacht
- Department of Pathology and Cancer Institute, Smilow Research Center, New York University School of Medicine, New York, NY, USA
| | - W S El-Deiry
- Laboratory of Translational Oncology and Experimental Cancer Therapeutics, Department of Medicine (Hematology/Oncology), Penn State Hershey Cancer Institute, Penn State College of Medicine, Hershey, PA, USA
| | - G M Fimia
- 1] Department of Biological and Environmental Sciences and Technologies (DiSTeBA), University of Salento, Lecce, Italy [2] Department of Epidemiology and Preclinical Research, National Institute for Infectious Diseases Lazzaro Spallanzani, Istituto Ricovero Cura Carattere Scientifico (IRCCS), Rome, Italy
| | - R A Flavell
- Department of Immunobiology, Yale School of Medicine, New Haven, CT, USA
| | - S Fulda
- Institute for Experimental Cancer Research in Pediatrics, Goethe University, Frankfurt, Germany
| | - C Garrido
- 1] INSERM, U866, Dijon, France [2] Faculty of Medicine, University of Burgundy, Dijon, France
| | - M-L Gougeon
- Antiviral Immunity, Biotherapy and Vaccine Unit, Infection and Epidemiology Department, Institut Pasteur, Paris, France
| | - D R Green
- Department of Immunology, St Jude's Children's Research Hospital, Memphis, TN, USA
| | - H Gronemeyer
- Department of Functional Genomics and Cancer, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France
| | - G Hajnoczky
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - J M Hardwick
- W Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins University, Baltimore, MD, USA
| | - M O Hengartner
- Institute of Molecular Life Sciences, University of Zurich, Zurich, Switzerland
| | - H Ichijo
- Laboratory of Cell Signaling, Graduate School of Pharmaceutical Sciences, University of Tokyo, Tokyo, Japan
| | - B Joseph
- Department of Oncology-Pathology, Cancer Centrum Karolinska (CCK), Karolinska Institute, Stockholm, Sweden
| | - P J Jost
- Medical Department for Hematology, Technical University of Munich, Munich, Germany
| | - T Kaufmann
- Institute of Pharmacology, Medical Faculty, University of Bern, Bern, Switzerland
| | - O Kepp
- 1] Equipe 11 labellisée par la Ligue Nationale contre le Cancer, Centre de Recherche des Cordeliers, Paris, France [2] INSERM, U1138, Gustave Roussy, Paris, France [3] Metabolomics and Cell Biology Platforms, Gustave Roussy Cancer Center, Villejuif, France
| | - D J Klionsky
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - R A Knight
- 1] Medical Molecular Biology Unit, Institute of Child Health, University College London (UCL), London, UK [2] Medical Research Council Toxicology Unit, Leicester, UK
| | - S Kumar
- 1] Centre for Cancer Biology, University of South Australia, Adelaide, SA, Australia [2] School of Medicine and School of Molecular and Biomedical Science, University of Adelaide, Adelaide, SA, Australia
| | - J J Lemasters
- Departments of Drug Discovery and Biomedical Sciences and Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, USA
| | - B Levine
- 1] Center for Autophagy Research, University of Texas, Southwestern Medical Center, Dallas, TX, USA [2] Howard Hughes Medical Institute (HHMI), Chevy Chase, MD, USA
| | - A Linkermann
- Division of Nephrology and Hypertension, Christian-Albrechts University, Kiel, Germany
| | - S A Lipton
- 1] The Scripps Research Institute, La Jolla, CA, USA [2] Sanford-Burnham Center for Neuroscience, Aging, and Stem Cell Research, La Jolla, CA, USA [3] Salk Institute for Biological Studies, La Jolla, CA, USA [4] University of California, San Diego (UCSD), San Diego, CA, USA
| | - R A Lockshin
- Department of Biological Sciences, St. John's University, Queens, NY, USA
| | - C López-Otín
- Department of Biochemistry and Molecular Biology, Faculty of Medecine, Instituto Universitario de Oncología (IUOPA), University of Oviedo, Oviedo, Spain
| | - E Lugli
- Unit of Clinical and Experimental Immunology, Humanitas Clinical and Research Center, Milan, Italy
| | - F Madeo
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - W Malorni
- 1] Department of Therapeutic Research and Medicine Evaluation, Istituto Superiore di Sanita (ISS), Roma, Italy [2] San Raffaele Institute, Sulmona, Italy
| | - J-C Marine
- 1] Laboratory for Molecular Cancer Biology, Center for the Biology of Disease, Leuven, Belgium [2] Laboratory for Molecular Cancer Biology, Center of Human Genetics, Leuven, Belgium
| | - S J Martin
- Department of Genetics, The Smurfit Institute, Trinity College, Dublin, Ireland
| | - J-C Martinou
- Department of Cell Biology, University of Geneva, Geneva, Switzerland
| | - J P Medema
- Laboratory for Experiments Oncology and Radiobiology (LEXOR), Academic Medical Center (AMC), Amsterdam, The Netherlands
| | - P Meier
- Institute of Cancer Research, The Breakthrough Toby Robins Breast Cancer Research Centre, London, UK
| | - S Melino
- Department of Chemical Sciences and Technologies, University of Rome Tor Vergata, Rome, Italy
| | - N Mizushima
- Graduate School and Faculty of Medicine, University of Tokyo, Tokyo, Japan
| | - U Moll
- Department of Pathology, Stony Brook University, Stony Brook, NY, USA
| | - C Muñoz-Pinedo
- Cell Death Regulation Group, Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Spain
| | - G Nuñez
- Department of Pathology and Comprehensive Cancer Center, University of Michigan Medical School, Ann Arbor, MI, USA
| | - A Oberst
- Department of Immunology, University of Washington, Seattle, WA, USA
| | - T Panaretakis
- Department of Oncology-Pathology, Cancer Centrum Karolinska (CCK), Karolinska Institute, Stockholm, Sweden
| | - J M Penninger
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna, Austria
| | - M E Peter
- Department of Hematology/Oncology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - M Piacentini
- 1] Department of Biology, University of Rome Tor Vergata; Rome, Italy [2] Department of Epidemiology and Preclinical Research, National Institute for Infectious Diseases Lazzaro Spallanzani, Istituto Ricovero Cura Carattere Scientifico (IRCCS), Rome, Italy
| | - P Pinton
- Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology and LTTA Center, University of Ferrara, Ferrara, Italy
| | - J H Prehn
- Department of Physiology and Medical Physics, Royal College of Surgeons, Dublin, Ireland
| | - H Puthalakath
- Department of Biochemistry, La Trobe Institute of Molecular Science, La Trobe University, Melbourne, Australia
| | - G A Rabinovich
- Laboratory of Immunopathology, Instituto de Biología y Medicina Experimental (IBYME), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - K S Ravichandran
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia, Charlottesville, VA, USA
| | - R Rizzuto
- Department Biomedical Sciences, University of Padova, Padova, Italy
| | - C M Rodrigues
- Research Institute for Medicines, Faculty of Pharmacy, University of Lisbon, Lisbon, Portugal
| | - D C Rubinsztein
- Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge School of Clinical Medicine, Cambridge, UK
| | - T Rudel
- Department of Microbiology, University of Würzburg; Würzburg, Germany
| | - Y Shi
- Soochow Institute for Translational Medicine, Soochow University, Suzhou, China
| | - H-U Simon
- Institute of Pharmacology, University of Bern, Bern, Switzerland
| | - B R Stockwell
- 1] Howard Hughes Medical Institute (HHMI), Chevy Chase, MD, USA [2] Departments of Biological Sciences and Chemistry, Columbia University, New York, NY, USA
| | - G Szabadkai
- 1] Department Biomedical Sciences, University of Padova, Padova, Italy [2] Department of Cell and Developmental Biology and Consortium for Mitochondrial Research, University College London (UCL), London, UK
| | - S W Tait
- 1] Cancer Research UK Beatson Institute, Glasgow, UK [2] Institute of Cancer Sciences, University of Glasgow, Glasgow, UK
| | - H L Tang
- W Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins University, Baltimore, MD, USA
| | - N Tavernarakis
- 1] Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion, Crete, Greece [2] Department of Basic Sciences, Faculty of Medicine, University of Crete, Heraklion, Crete, Greece
| | - Y Tsujimoto
- Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka, Japan
| | - T Vanden Berghe
- 1] VIB Inflammation Research Center, Ghent, Belgium [2] Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - P Vandenabeele
- 1] VIB Inflammation Research Center, Ghent, Belgium [2] Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium [3] Methusalem Program, Ghent University, Ghent, Belgium
| | - A Villunger
- Division of Developmental Immunology, Biocenter, Medical University Innsbruck, Innsbruck, Austria
| | - E F Wagner
- Cancer Cell Biology Program, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - H Walczak
- Centre for Cell Death, Cancer and Inflammation (CCCI), UCL Cancer Institute, University College London (UCL), London, UK
| | - E White
- Rutgers Cancer Institute of New Jersey, New Brunswick, NJ, USA
| | - W G Wood
- 1] Department of Pharmacology, University of Minnesota School of Medicine, Minneapolis, MN, USA [2] Geriatric Research, Education and Clinical Center, VA Medical Center, Minneapolis, MN, USA
| | - J Yuan
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Z Zakeri
- 1] Department of Biology, Queens College, Queens, NY, USA [2] Graduate Center, City University of New York (CUNY), Queens, NY, USA
| | - B Zhivotovsky
- 1] Division of Toxicology, Institute of Environmental Medicine, Karolinska Institute, Stockholm, Sweden [2] Faculty of Fundamental Medicine, Lomonosov Moscow State University, Moscow, Russia
| | - G Melino
- 1] Department of Experimental Medicine and Surgery, University of Rome Tor Vergata, Rome, Italy [2] Medical Research Council Toxicology Unit, Leicester, UK
| | - G Kroemer
- 1] Equipe 11 labellisée par la Ligue Nationale contre le Cancer, Centre de Recherche des Cordeliers, Paris, France [2] Université Paris Descartes/Paris V, Sorbonne Paris Cité, Paris, France [3] INSERM, U1138, Gustave Roussy, Paris, France [4] Metabolomics and Cell Biology Platforms, Gustave Roussy Cancer Center, Villejuif, France [5] Pôle de Biologie, Hôpital Européen Georges Pompidou, AP-HP, Paris, France
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Leontieva OV, Demidenko ZN, Blagosklonny MV. Rapamycin reverses insulin resistance (IR) in high-glucose medium without causing IR in normoglycemic medium. Cell Death Dis 2014; 5:e1214. [PMID: 24810050 PMCID: PMC4047870 DOI: 10.1038/cddis.2014.178] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Revised: 03/17/2014] [Accepted: 03/26/2014] [Indexed: 02/08/2023]
Abstract
Mammalian target of rapamycin (mTOR) is involved in insulin resistance (IR) and diabetic retinopathy. In retinal pigment epithelial (RPE) cells, insulin activates the mTOR pathway, inducing hypoxia-inducible factor-1α (HIF-1α) and HIF-dependent transcription in serum-free minimum essential medium Eagle (MEM). Serendipitously, we found that insulin failed to induce the HIF-1α-dependent response, when RPE cells were cultured in Dulbecco's modification of Eagle's medium (DMEM). Whereas concentration of glucose in MEM corresponds to normal glucose levels in blood (5.5 mM), its concentration in DMEM corresponds to severe diabetic hyperglycemia (25 mM). Addition of glucose to MEM also caused IR. Glucose-mediated IR was characterized by basal activation of mTORC1 and its poor inducibility by insulin. Basal levels of phosphorylated S6 kinase (S6K), S6 and insulin receptor substrate 1 (IRS1) S635/639 were high, whereas their inducibilities were decreased. Insulin-induced Akt phosphorylation was decreased and restored by rapamycin and an inhibitor of S6K. IR was associated with de-phosphorylation of IRS1 at S1011, which was reversed by rapamycin. Both short (16–40 h) and chronic (2 weeks) treatment with rapamycin reversed IR. Furthermore, rapamycin did not impair Akt activation in RPE cells cultured in normoglycemic media. In contrast, Torin 1 blocked Akt activation by insulin. We conclude that by activating mTOR/S6K glucose causes feedback IR, preventable by rapamycin. Rapamycin does not cause IR in RPE cells regardless of the duration of treatment. We confirmed that rapamycin also did not impair phosphorylation of Akt at T308 and S473 in normal myoblast C2C12 cells. Our work provides insights in glucose-induced IR and suggests therapeutic approaches to treat patients with IR and severe hyperglycemia and to prevent diabetic complications such as retinopathy. Also our results prompt to reconsider physiological relevance of numerous data and paradigms on IR given that most cell lines are cultured with grossly super-physiological levels of glucose.
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Affiliation(s)
- O V Leontieva
- Department of Cell Stress Biology, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, NY, USA
| | - Z N Demidenko
- Department of Cell Stress Biology, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, NY, USA
| | - M V Blagosklonny
- Department of Cell Stress Biology, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, NY, USA
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4
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Galluzzi L, Vitale I, Abrams JM, Alnemri ES, Baehrecke EH, Blagosklonny MV, Dawson TM, Dawson VL, El-Deiry WS, Fulda S, Gottlieb E, Green DR, Hengartner MO, Kepp O, Knight RA, Kumar S, Lipton SA, Lu X, Madeo F, Malorni W, Mehlen P, Nuñez G, Peter ME, Piacentini M, Rubinsztein DC, Shi Y, Simon HU, Vandenabeele P, White E, Yuan J, Zhivotovsky B, Melino G, Kroemer G. Molecular definitions of cell death subroutines: recommendations of the Nomenclature Committee on Cell Death 2012. Cell Death Differ 2012; 19:107-20. [PMID: 21760595 PMCID: PMC3252826 DOI: 10.1038/cdd.2011.96] [Citation(s) in RCA: 1803] [Impact Index Per Article: 150.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2011] [Accepted: 06/13/2011] [Indexed: 02/07/2023] Open
Abstract
In 2009, the Nomenclature Committee on Cell Death (NCCD) proposed a set of recommendations for the definition of distinct cell death morphologies and for the appropriate use of cell death-related terminology, including 'apoptosis', 'necrosis' and 'mitotic catastrophe'. In view of the substantial progress in the biochemical and genetic exploration of cell death, time has come to switch from morphological to molecular definitions of cell death modalities. Here we propose a functional classification of cell death subroutines that applies to both in vitro and in vivo settings and includes extrinsic apoptosis, caspase-dependent or -independent intrinsic apoptosis, regulated necrosis, autophagic cell death and mitotic catastrophe. Moreover, we discuss the utility of expressions indicating additional cell death modalities. On the basis of the new, revised NCCD classification, cell death subroutines are defined by a series of precise, measurable biochemical features.
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Affiliation(s)
- L Galluzzi
- INSERM U848, ‘Apoptosis, Cancer and Immunity', 94805 Villejuif, France
- Institut Gustave Roussy, 94805 Villejuif, France
- Université Paris Sud-XI, 94805 Villejuif, France
| | - I Vitale
- INSERM U848, ‘Apoptosis, Cancer and Immunity', 94805 Villejuif, France
- Institut Gustave Roussy, 94805 Villejuif, France
- Université Paris Sud-XI, 94805 Villejuif, France
| | - J M Abrams
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - E S Alnemri
- Department of Biochemistry and Molecular Biology, Center for Apoptosis Research, Kimmel Cancer Institute, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - E H Baehrecke
- Department of Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - M V Blagosklonny
- Department of Cell Stress Biology, Roswell Park Cancer Institute, Buffalo, NY 14263, USA
| | - T M Dawson
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - V L Dawson
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - W S El-Deiry
- Cancer Institute Penn State, Hershey Medical Center, Philadelphia, PA 17033, USA
| | - S Fulda
- Institute for Experimental Cancer Research in Pediatrics, Goethe University, Frankfurt 60528, Germany
| | - E Gottlieb
- The Beatson Institute for Cancer Research, Glasgow G61 1BD, UK
| | - D R Green
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - M O Hengartner
- Institute of Molecular Life Sciences, University of Zurich, 8057 Zurich, Switzerland
| | - O Kepp
- INSERM U848, ‘Apoptosis, Cancer and Immunity', 94805 Villejuif, France
- Institut Gustave Roussy, 94805 Villejuif, France
- Université Paris Sud-XI, 94805 Villejuif, France
| | - R A Knight
- Institute of Child Health, University College London, London WC1N 3JH, UK
| | - S Kumar
- Centre for Cancer Biology, SA Pathology, Adelaide, South Australia 5000, Australia
- Department of Medicine, University of Adelaide, Adelaide, South Australia 5005, Australia
| | - S A Lipton
- Sanford-Burnham Medical Research Institute, San Diego, CA 92037, USA
- Salk Institute for Biological Studies, , La Jolla, CA 92037, USA
- The Scripps Research Institute, La Jolla, CA 92037, USA
- Univerisity of California, San Diego, La Jolla, CA 92093, USA
| | - X Lu
- Ludwig Institute for Cancer Research, Oxford OX3 7DQ, UK
| | - F Madeo
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - W Malorni
- Department of Therapeutic Research and Medicines Evaluation, Section of Cell Aging and Degeneration, Istituto Superiore di Sanità, 00161 Rome, Italy
- Istituto San Raffaele Sulmona, 67039 Sulmona, Italy
| | - P Mehlen
- Apoptosis, Cancer and Development, CRCL, 69008 Lyon, France
- INSERM, U1052, 69008 Lyon, France
- CNRS, UMR5286, 69008 Lyon, France
- Centre Léon Bérard, 69008 Lyon, France
| | - G Nuñez
- University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - M E Peter
- Northwestern University Feinberg School of Medicine, Chicago, IL 60637, USA
| | - M Piacentini
- Laboratory of Cell Biology, National Institute for Infectious Diseases IRCCS ‘L Spallanzani', 00149 Rome, Italy
- Department of Biology, University of Rome ‘Tor Vergata', 00133 Rome, Italy
| | - D C Rubinsztein
- Cambridge Institute for Medical Research, Cambridge CB2 0XY, UK
| | - Y Shi
- Shanghai Institutes for Biological Sciences, 200031 Shanghai, China
| | - H-U Simon
- Institute of Pharmacology, University of Bern, 3010 Bern, Switzerland
| | - P Vandenabeele
- Department for Molecular Biology, Gent University, 9052 Gent, Belgium
- Department for Molecular Biomedical Research, VIB, 9052 Gent, Belgium
| | - E White
- The Cancer Institute of New Jersey, New Brunswick, NJ 08903, USA
| | - J Yuan
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - B Zhivotovsky
- Institute of Environmental Medicine, Division of Toxicology, Karolinska Institutet, 17177 Stockholm, Sweden
| | - G Melino
- Biochemical Laboratory IDI-IRCCS, Department of Experimental Medicine, University of Rome ‘Tor Vergata', 00133 Rome, Italy
- Medical Research Council, Toxicology Unit, Leicester University, Leicester LE1 9HN, UK
| | - G Kroemer
- INSERM U848, ‘Apoptosis, Cancer and Immunity', 94805 Villejuif, France
- Metabolomics Platform, Institut Gustave Roussy, 94805 Villejuif, France
- Centre de Recherche des Cordeliers, 75005 Paris, France
- Pôle de Biologie, Hôpital Européen Georges Pompidou, AP-HP, 75908 Paris, France
- Université Paris Descartes, Paris 5, 75270 Paris, France
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5
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Blagosklonny MV. Solving puzzles of aging: From disposable soma to signal-transduction pathways. RUSS J GEN CHEM+ 2010. [DOI: 10.1134/s1070363210070364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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6
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Broude EV, Swift ME, Vivo C, Chang BD, Davis BM, Kalurupalle S, Blagosklonny MV, Roninson IB. p21Waf1/Cip1/Sdi1 mediates retinoblastoma protein degradation. Oncogene 2007; 26:6954-8. [PMID: 17486059 DOI: 10.1038/sj.onc.1210516] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Damage-induced G1 checkpoint in mammalian cells involves upregulation of p53, which activates transcription of p21(Waf1) (CDKN1A). Inhibition of cyclin-dependent kinase (CDK)2 and CDK4/6 by p21 leads to dephosphorylation and activation of Rb. We now show that ectopic p21 expression in human HT1080 fibrosarcoma cells causes not only dephosphorylation but also depletion of Rb; this effect was p53-independent and susceptible to a proteasome inhibitor. CDK inhibitor p27 (CDKN1B) also caused Rb dephosphorylation and depletion, but another CDK inhibitor p16 (CDKN2A) induced only dephosphorylation but not depletion of Rb. Rb depletion was observed in both HT1080 and HCT116 colon carcinoma cells, where p21 was induced by DNA-damaging agents. Rb depletion after DNA damage did not occur in the absence of p21, and it was reduced when p21 induction was inhibited by p21-targeting short hairpin RNA or by a transdominant inhibitor of p53. These results indicate that p21 both activates Rb through dephosphorylation and inactivates it through degradation, suggesting negative feedback regulation of damage-induced cell-cycle checkpoint arrest.
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Affiliation(s)
- E V Broude
- Cancer Center, Ordway Research Institute, Albany, NY 12208, USA
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7
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Abstract
Tumor stem cells are quiescent and, therefore, resistant to therapy, yet harbor the capacity to replenish a tumor after therapy. Therefore, it is tempting to explain all therapeutic failures by the persistence of tumor stem cells. Yet, this explanation is relevant only to initial stages of stem-cell-dependent tumors (such as chronic myeloid leukemia) that, actually, are well controlled by therapy. In advanced cancers that poorly respond to therapy, quiescent tumor stem cells play a negligible role. Instead, proliferating cells determine disease progression, prognosis, therapeutic failures, and resistance to therapy. And therapy fails not because it eliminates only proliferating tumor cells, but because it does not eliminate them. With noticeable exceptions, it is the proliferating cell that should be targeted, whereas resting cancer cells including stem and dormant cells need to be targeted only when they 'wake up'. Finally, I discuss a strategy of selectively killing dominant proliferating clones, including proliferating stem-like and drug-resistant cancer cells, while sparing normal cells.
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Affiliation(s)
- M V Blagosklonny
- Cancer Center, Ordway Research Institute, Albany, NY 12208, USA.
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8
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Demidenko ZN, Vivo C, Halicka HD, Li CJ, Bhalla K, Broude EV, Blagosklonny MV. Pharmacological induction of Hsp70 protects apoptosis-prone cells from doxorubicin: comparison with caspase-inhibitor- and cycle-arrest-mediated cytoprotection. Cell Death Differ 2005; 13:1434-41. [PMID: 16311509 DOI: 10.1038/sj.cdd.4401812] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Selective modulation of cell death is important for rational chemotherapy. By depleting Hsp90-client oncoproteins, geldanamycin (GA) and 17-allylamino-17-demethoxy-GA (17-AAG) (heat-shock protein-90-active drugs) render certain oncoprotein-addictive cancer cells sensitive to chemotherapy. Here we investigated effects of GA and 17-AAG in apoptosis-prone cells such as HL60 and U937. In these cells, doxorubicin (DOX) caused rapid apoptosis, whereas GA-induced heat-shock protein-70 (Hsp70) (a potent inhibitor of apoptosis) and G1 arrest without significant apoptosis. GA blocked caspase activation and apoptosis and delayed cell death caused by DOX. Inhibitors of translation and transcription and siRNA Hsp70 abrogated cytoprotective effects of GA. Also GA failed to protect HL60 cells from cytotoxicity of actinomycin D and flavopiridol (FL), inhibitors of transcription. We next compared cytoprotection by GA-induced Hsp70, caspase inhibitors (Z-VAD-fmk) and cell-cycle arrest. Whereas cell-cycle arrest protected HL60 cells from paclitaxel (PTX) but not from FL and DOX, Z-VAD-fmk prevented FL-induced apoptosis but was less effective against DOX and PTX. Thus, by inducing Hsp70, GA protected apoptosis-prone cells in unique and cell-type selective manner. Since GA does not protect apoptosis-reluctant cancer cells, we envision a therapeutic strategy to decrease side effects of chemotherapy without affecting its therapeutic efficacy.
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Affiliation(s)
- Z N Demidenko
- Brander Cancer Research Institute, New York Medical College, Valhalla, NY, USA
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9
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Kroemer G, El-Deiry WS, Golstein P, Peter ME, Vaux D, Vandenabeele P, Zhivotovsky B, Blagosklonny MV, Malorni W, Knight RA, Piacentini M, Nagata S, Melino G. Classification of cell death: recommendations of the Nomenclature Committee on Cell Death. Cell Death Differ 2005; 12 Suppl 2:1463-7. [PMID: 16247491 DOI: 10.1038/sj.cdd.4401724] [Citation(s) in RCA: 511] [Impact Index Per Article: 26.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- G Kroemer
- CNRS-UMR8125, Institut Gustave Roussy, 39 rue Camille-Desmoulins, F-94805 Villejuif, France.
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10
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Abstract
Carcinogenesis and cancer therapy are two sides of the same coin, such that the same cytotoxic agent can cause cancer and be used to treat cancer. This review links carcinogenesis, chemoprevention and cancer therapy in one process driven by cytotoxic agents (carcinoagents) that select either for or against cells with oncogenic alterations. By unifying therapy and cancer promotion and by distinguishing nononcogenic and oncogenic mechanisms of resistance, I discuss anticancer- and chemopreventive agent-induced carcinogenesis and tumor progression and, vice versa, carcinogens as anticancer drugs, anticancer drugs as chemopreventive agents and exploiting oncogene-addiction and drug resistance for chemoprevention and cancer therapy.
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Affiliation(s)
- M V Blagosklonny
- Brander Cancer Research Institute, New York Medical College, 19 Bradhurst Ave., Hawthorne, NY 10532, USA.
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11
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Affiliation(s)
- M V Blagosklonny
- Brander Cancer Research Institute, New York Medical College, Valhalla, NY 10532, USA.
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12
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Abstract
Instead of exploiting the differences between normal and cancer cells, seemingly unrelated anticancer modalities (from immunotherapy to hormones) exploit (a) the differences between various normal tissues and (b) tissue-specific similarities of normal and cancer cells. Although these therapies are successfully used for years to treat leukaemia and cancer, their unifying principles have never been explicitly formulated: namely, they are aimed at differentiated cells and normal tissues and target both normal and cancer cells in a tissue-specific manner. Whereas tiny differences between cancer and normal cells have yet to be successfully exploited for selective anticancer therapy, numerous tissue-specific differences (e.g. differences between melanocytes, prostate, thyroid and breast cells) provide a means to attack selectively that exact tissue that produced cancer. Despite inherent limitations, such as fostering resistance and dedifferentiation, tissue-selective therapy have enormous potentials to control cancer.
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Affiliation(s)
- M V Blagosklonny
- Department of Medicine, New York Medical College, Valhalla, NY 10595, USA.
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13
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Liu YQ, Kyle E, Patel S, Housseau F, Hakim F, Lieberman R, Pins M, Blagosklonny MV, Bergan RC. Prostate cancer chemoprevention agents exhibit selective activity against early stage prostate cancer cells. Prostate Cancer Prostatic Dis 2002; 4:81-91. [PMID: 12497043 DOI: 10.1038/sj.pcan.4500506] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2000] [Accepted: 12/05/2000] [Indexed: 11/09/2022]
Abstract
Preclinical models for the identification of prostate cancer chemoprevention agents are lacking. Based upon the notion that clinically useful chemoprevention agents should exhibit selective activity against early stage disease, studies were undertaken to assess whether chemoprevention agents selectively inhibited the growth of early stage prostate cancer, as compared to late stage cancer. First, a series of cell and molecular studies were performed, which, when taken together, validated the use of a panel of prostate cell lines as a model of the different stages of carcinogenesis. Next, therapeutic responsiveness to ten different cytotoxic or chemoprevention agents was evaluated. Chemoprevention agents exhibited selective activity against normal and early transformed prostate tissue, whereas cytotoxic agents were non-specific. Selective activity against early versus advanced prostate cancer cells is identified as a potential screening method for chemoprevention agents.Prostate Cancer and Prostatic Diseases (2001) 4, 81-91
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Affiliation(s)
- Y Q Liu
- Division of Hematology/Oncology, Department of Medicine, Northwest University Medical School and the Robert H. Lurie Cancer Center of Northwestern University, Chicago, USA
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14
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Abstract
Geldanamycin (GA), herbimycin A and radicicol bind heat-shock protein-90 (Hsp90) and destabilize its client proteins including v-Src, Bcr-Abl, Raf-1, ErbB2, some growth factor receptors and steroid receptors. Thus, Hsp90-active agents induce ubiquitination and proteasomal degradation of numerous oncoproteins. Depending on the cellular context, HSP90-active agents cause growth arrest, differentiation and apoptosis, or can prevent apoptosis. HSP-active agents are undergoing clinical trials. Like targets of most chemotherapeutics, Hsp90 is not a cancer-specific protein. By attacking a nonspecific target, HSP-90-active compounds still may preferentially kill certain tumor cells. How can this be achieved? How can therapeutic potentials be exploited? This article starts the discussion.
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15
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Blagosklonny MV. STI-571 must select for drug-resistant cells but 'no cell breathes fire out of its nostrils like a dragon'. Leukemia 2002; 16:570-2. [PMID: 11960334 DOI: 10.1038/sj.leu.2402409] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2001] [Accepted: 11/30/2001] [Indexed: 11/09/2022]
Abstract
Seemingly disappointing, the Bcr-Abl kinase inhibitor STI-571 shares an 'unfortunate' characteristic with conventional cancer drugs: the development of drug resistance. I argue that the resistance must develop even faster to STI-571 than to conventional drugs, because STI-571 is so effective. This is predictable, but is it inevitable? And how do mechanisms of resistance in relapse depend on a degree of remission. In addition to mutation rate and number of tumor cells, one additional factor determines relapse vs. 'extinction' of the leukemia cell population.
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MESH Headings
- Benzamides
- Drug Resistance, Neoplasm
- Enzyme Inhibitors/pharmacology
- Fusion Proteins, bcr-abl
- Humans
- Imatinib Mesylate
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/genetics
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/pathology
- Piperazines/pharmacology
- Protein-Tyrosine Kinases/antagonists & inhibitors
- Pyrimidines/pharmacology
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Affiliation(s)
- M V Blagosklonny
- Medicine Branch, National Cancer Institute, NIH, Bethesda, MD 20892, USA
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16
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Abstract
Carcinogens induce carcinogen-specific genetic instability (defects in DNA repair). According to the 'direct-selection' model, defects in DNA repair per se provide an immediate growth advantage. According to the 'associated-selection' model, carcinogens merely select for cells with adaptive mutations. Like any mutations, adaptive mutations occur predominantly in genetically unstable cells. The 'associated-selection' model predicts that carcinogen-driven selection minimizes cytotoxic but maximizes mutagenic effects of carcinogens. A purely mutagenic (neither cytotoxic, nor cytostatic) environment will favor effective DNA repair, whereas any growth-limiting conditions (telomerase deficiency, anticancer drugs) will select for genetically unstable cells. Genetic instability is a postmark of selective pressure rather than a hallmark of cancer per se. Once selected, genetic instability facilitates the development of resistance to any other growth-limiting conditions. As an example, a putative link between prior exposure to carcinogens and the ability to develop a telomerase-independent growth is discussed.
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Affiliation(s)
- M V Blagosklonny
- Medicine Branch, National Cancer Institute, NIH, Bldg. 10, R 12 N 226, Bethesda, MD 20892, USA.
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17
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Blagosklonny MV, Fojo T, Bhalla KN, Kim JS, Trepel JB, Figg WD, Rivera Y, Neckers LM. The Hsp90 inhibitor geldanamycin selectively sensitizes Bcr-Abl-expressing leukemia cells to cytotoxic chemotherapy. Leukemia 2001; 15:1537-43. [PMID: 11587211 DOI: 10.1038/sj.leu.2402257] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The Bcr-Abl fusion protein drives leukemogenesis and can render leukemia cells resistant to conventional chemotherapy. Geldanamycin (GA), a drug which destabilizes Hsp90-associated proteins, depletes cells of Bcr-Abl, an Hsp90 client, but not of Abl. Both HL60 cells transfected with Bcr-Abl and naturally Ph1-positive K562 leukemia cells are resistant to most cytotoxic drugs, but were found to be sensitive to GA. Furthermore, GA sensitized Bcr-Abl-expressing cells to doxorubicin (DOX) and paclitaxel (PTX). In contrast, in parental HL60 cells, 90 nM GA inhibited PARP cleavage, nuclear fragmentation, and cell death caused by 500 ng/ml DOX. Like GA, STI 571 (an inhibitor of the Abl kinase) sensitized Bcr-Abl-expressing cells to DOX. Unlike GA, STI 571 did not antagonize the cytotoxic effects of DOX in parental HL60 cells. These results indicate that sensitization of Bcr-Abl-expressing cells, but not desensitization of HL60 cells, depends on inhibition of Bcr-Abl. Thus, GA differentially affects leukemia cells depending on their Bcr-Abl expression and selectively increases apoptosis in Bcr-Abl-expressing cells.
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Affiliation(s)
- M V Blagosklonny
- Department of Developmental Therapeutics, Medicine Branch, National Cancer Institute, NIH, Bethesda and Rockville, MD 20892, USA
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18
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Abstract
Although the Bcl-2 family members and p53 are involved in the regulation of apoptosis, the status of apoptotic machinery (eg caspases) plays a major role in determining the mode and timing of cell death. If the apoptotic machinery is lost, inhibited, or intrinsically inactivated, the "death stars", Bcl-2 and p53, may become irrelevant to cell death. In this light, high levels of Bcl-2 may indicate that downstream apoptotic pathways are still functional. This explains why Bcl-2 overexpression can be a marker of chemosensitivity and favorable prognosis in certain cancers and why retention of wild-type p53 may manifest inactivation of caspases in aggressive cancers.
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Affiliation(s)
- M V Blagosklonny
- Medicine Branch, Bldg. 10, Room 12 N 226, NIH, Bethesda, MD 20892, USA. mikhailb2box-m.nih.gov
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19
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Abstract
Could a rational, hypothesis-driven and well-tolerated therapy drive tumor progression? This scenario can be foreseen for antiangiogenic therapy, despite it is one of the most elegant anticancer strategies. Antiangiogenic agents inhibit growth of endothelial cells resulting in tumor hypoxia and starvation which in turn inhibit tumor growth. On the other hand, it is known that hypoxia selects for a highly aggressive and metastatic cancer and is associated with unfavorable prognosis. This review attempts to reconcile these opposite notions and to revisit the thesis that antiangiogenic therapy is "resistant to resistance". The latter logical paradigm is based on the notion that endothelial cells cannot become drug resistant. Although endothelial cells may not acquire drug-resistance, cancer cells can acquire hypoxia-resistance which is also associated with the resistance to growth arrest and apoptosis as well as high metastatic potentials. Hypoxia-inducible factor (HIF-1) renders cells capable of surviving hypoxia and stimulating endothelial growth. Disruption of the HIF-1 pathway inhibits tumor growth, indicating HIF-1 as a potential anticancer target. Furthermore, inhibition of HIF-1 is a mechanism-based antiangiogenic strategy because it is the HIF-mediated response that drives tumor angiogenesis. Pharmacological approaches to HIF-1 inhibition are discussed.
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Affiliation(s)
- M V Blagosklonny
- Medicine Branch, National Institutes of Health, Bethesda, MD 20892, USA.
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20
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Giannakakou P, Robey R, Fojo T, Blagosklonny MV. Low concentrations of paclitaxel induce cell type-dependent p53, p21 and G1/G2 arrest instead of mitotic arrest: molecular determinants of paclitaxel-induced cytotoxicity. Oncogene 2001; 20:3806-13. [PMID: 11439344 DOI: 10.1038/sj.onc.1204487] [Citation(s) in RCA: 152] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2001] [Revised: 03/26/2001] [Accepted: 03/26/2001] [Indexed: 12/18/2022]
Abstract
Paclitaxel (PTX), a microtubule-active agent, blocks cell proliferation by inhibiting mitotic progression leading to mitotic and postmitotic arrest and cell death. Here we demonstrate for the first time that very low concentrations of PTX (3-6 nM) can completely inhibit cell proliferation without arresting cells at mitosis. At these low concentrations that are insufficient to inhibit mitotic progression, PTX induced both p53 and p21 causing G1 and G2 arrest in A549. In contrast, low PTX concentrations failed to induce G1 and G2 arrest in A549/E6 cells, that do not express p53. Furthermore, we observed that the levels of p53 and p21 induced by adriamycin and by low concentrations of PTX in A549 cells were comparable. This observation led us to conclude that low concentrations of PTX can induce p53 and p21 sufficiently to cause G1 and G2. Many other cell lines, including HCT116 cells, do not readily upregulate p53 in response to PTX, and therefore undergo exclusively mitotic and postmitotic arrest after PTX treatment. At low concentrations that do not cause mitotic arrest, PTX did not significantly inhibit proliferation of these cells. In HCT116 cells, loss of p53 (HCT/p53(-/-)) or p21 (HCT/p21(-/-)) affects both Bax and Bcl-2 expression. In cells lacking p53, levels of Bax and p21 were decreased. In cells lacking p21, levels of wt p53 were highly increased to compensate for the loss of p21. This in turn results in upregulation of Bax and downregulation of Bcl-2 resulting in an increase of the apoptotic Bax/Bcl2 ratio consistent with increased sensitivity of these cells to apoptotic stimuli. High levels of p53 and Bax/Bcl-2 ratio can also explain why loss of p21 is rarely found in human cancer.
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Affiliation(s)
- P Giannakakou
- Medicine Branch, National Cancer Institute, NIH, Bethesda, Maryland, MD 20892, USA
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21
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Blagosklonny MV, Giannakakou P, Romanova LY, Ryan KM, Vousden KH, Fojo T. Inhibition of HIF-1- and wild-type p53-stimulated transcription by codon Arg175 p53 mutants with selective loss of functions. Carcinogenesis 2001; 22:861-7. [PMID: 11375890 DOI: 10.1093/carcin/22.6.861] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Overexpression of ectopic mutant p53 represses wild-type p53-stimulated transcription, known as a dominant negative effect. On the other hand, overexpression of wild-type p53 can repress transcription stimulated by several transcription factors, including hypoxia-inducible factor-1 (HIF-1). Using a panel of well-characterized Arg175 p53 mutants we found that only mutants (Tyr175, Trp175, Asp175 and Phe175) which have completely lost their ability to transactivate repress wild-type p53-stimulated Bax, p21 and PG13 promoter constructs. In contrast, Asn175, Gln175, Leu175 and Pro175 mutants which partially retained transactivating functions did not exert dominant negative effects against PG13 and p21 promoter constructs. However, these latter mutants failed to activate Bax and, instead, exerted a dominant negative effect on a Bax-Luc promoter construct. We conclude that a dominant negative effect is promoter selective as a consequence of selective loss of transactivating function. Albeit less potent than wild-type p53, all Arg175 p53 mutants retained partial ability to repress HIF-1-stimulated transcription. We propose that transrepression and the dominant negative effect have similar mechanisms and may involve competition with transcription factors (wild-type p53, HIF-1, etc.) for cofactors such as p300. Thus, a p53(22/23) mutant, which is deficient in p300 binding, did not exert dominant negative effects. Like transrepression, the dominant negative effect required overexpression of mutant p53 and, therefore, is not dominant. In the presence of a wild-type p53 allele, levels of endogenous mutant p53 protein were low in heterozygous cells. Endogenous mutant p53 became overexpressed only after loss of the second p53 allele. Therefore, endogenous mutant p53s are unable to display a dominant negative effect. This explains why loss of the second p53 allele is required to eliminate p53 functions in cancer cells.
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Affiliation(s)
- M V Blagosklonny
- Medicine Branch, National Cancer Institute, NIH, Bethesda, MD 20892, USA.
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22
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Abstract
Recent evidence indicates that anti-apoptotic functions of BcI-2 can be regulated by its phosphorylation. According to the 'mitotic arrest-induced' model, multi-site phosphorylation of the BcI-2 loop domain is followed by cell death. In contrast, in cytokine-dependent cell lines, cytokines mediate phosphorylation of BcI-2 on S70, preventing apoptosis. As discussed in this review, these models are not mutually exclusive but reflect different cellular contexts. During mitotic arrest, signal transduction is unique and is fundamentally different from classical mitogenic signaling, since the nucleus membrane is dissolved, gene expression is reduced, and numerous kinases and regulatory proteins are hyperphosphorylated. Hyperphosphorylation of BcI-2 mediated by paclitaxel and other microtubule-active drugs is strictly dependent on targeting microtubules that in turn cause mitotic arrest. In addition to serine-70 (S70), microtubule-active agents promote phosphorylation of S87 and threonine-69 (T69), inactivating BcI-2. A major obstacle for identification of the mitotic BcI-2 kinase(s) is that inhibition of putative kinase(s) by any means (dominant-negative mutants, antisense oligonucleotides, pharmacological agents) may arrest cycle, preventing mitosis and BcI-2 phosphorylation. The role of BcI-2 phosphorylation in cell death is discussed.
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Affiliation(s)
- M V Blagosklonny
- Medicine Branch, Building 10, R 12N226, National Cancer Institute, NIH, Bethesda, MD 20892, USA
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23
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Kang MH, Figg WD, Ando Y, Blagosklonny MV, Liewehr D, Fojo T, Bates SE. The P-glycoprotein antagonist PSC 833 increases the plasma concentrations of 6alpha-hydroxypaclitaxel, a major metabolite of paclitaxel. Clin Cancer Res 2001; 7:1610-7. [PMID: 11410497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
PURPOSE Overexpression of P-glycoprotein (Pgp) is one mechanism of drug resistance in cancer chemotherapy. A Phase I trial was conducted using PSC 833, a Pgp antagonist, in combination with paclitaxel in patients with refractory cancer. The objective of this study was to assess the effect of PSC 833 on the metabolism of paclitaxel and characterize the differences in 6alpha-hydroxypaclitaxel pharmacokinetics. In addition, we examined the possibility of enhanced cytotoxicity of paclitaxel by the coexistence of 6alpha-hydroxypaclitaxel. EXPERIMENTAL DESIGN Patients received paclitaxel 35 mg/m(2)/day by continuous intravenous infusion (CIVI) x 4 days without PSC 833 in cycle 1 and escalating doses of paclitaxel (13.1, 17.5, or 21.3 mg/m(2)/day CIVI x 4 days) with 5 mg/kg PSC 833 by mouth every 6 h x 7 days in cycle 2. Plasma samples were analyzed for both paclitaxel and its major metabolite with high-performance liquid chromatography methods. Using human liver microsomes, we studied the effect of PSC 833 on the metabolism of paclitaxel. In addition, the in vitro cytotoxicity of 6alpha-hydroxypaclitaxel alone and in combination with paclitaxel was evaluated. RESULTS Twenty-one of 22 patients had a metabolite peak (6alpha-hydroxypaclitaxel) observed in the chromatogram of plasma samples from cycle 2 when they received paclitaxel in combination with PSC 833. This metabolite was not detectable in plasma obtained during the first cycle when they received paclitaxel without PSC 833. During cycle 2, the mean concentrations of 6alpha-hydroxypaclitaxel and paclitaxel were 0.10 +/- 0.074 and 0.079 +/- 0.041 microg/ml, respectively. A moderate association was observed between total bilirubin and 6alpha-hydroxypaclitaxel concentrations (P = 0.015, r = 0.52; n = 21). Human liver microsome experiments showed that a PSC 833 concentration as high as 10 microM did not affect the production of 6alpha-hydroxypaclitaxel. Paclitaxel cytotoxicity in HL60 and K562 human leukemia cells was increased in the presence of noncytotoxic concentrations of 6alpha-hydroxypaclitaxel. CONCLUSIONS PSC 833 increases the plasma concentration of 6alpha-hydroxypaclitaxel during paclitaxel therapy. Inhibition of cytochrome P-450 3A4 by PSC 833 may explain this in part, although other mechanisms cannot be excluded.
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Affiliation(s)
- M H Kang
- Medicine Branch, Division of Clinical Sciences, National Cancer Institute, NIH, Bethesda, Maryland 20892, USA
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24
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Blagosklonny MV. Treatment with inhibitors of caspases, that are substrates of drug transporters, selectively permits chemotherapy-induced apoptosis in multidrug-resistant cells but protects normal cells. Leukemia 2001; 15:936-41. [PMID: 11417480 DOI: 10.1038/sj.leu.2402127] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Many chemotherapeutic agents induce apoptosis in tumor cells, but killing of normal cells remains a major obstacle. Development of multidrug resistance further limits chemotherapy in cancer. Here, I show that multidrug resistance can be exploited for selective killing of multidrug-resistant cells by a combination of an apoptosis-inducing agent that is not a substrate of either Pgp or MRP (e.g. flavopiridol) with a caspase inhibitor that is a substrate (e.g. Z-DEVD-fmk). In normal cells, treatment with caspase inhibitors prevented PARP cleavage, nuclear fragmentation, and cell death caused by flavopiridol or epothilone B. In contrast, Pgp- and MRP-expressing cells were not rescued by caspase inhibitors. Furthermore, reversal of drug resistance renders Pgp cells sensitive to caspase inhibitors abolishing therapeutic advantage. Thus, caspase inhibitors, that are inactive in multidrug-resistant cells, protect normal but not multidrug-resistant cells against chemotherapy, permitting selective eradication of multidrug-resistant cells. Clinical application of this approach may diminish the toxic side-effects of chemotherapy in patients with multidrug-resistant tumors.
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Affiliation(s)
- M V Blagosklonny
- Medicine Branch, National Cancer Institute, Building 10, R 12N226 NIH, Bethesda, MD 20892, USA
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Blagosklonny MV, Pardee AB. Exploiting cancer cell cycling for selective protection of normal cells. Cancer Res 2001; 61:4301-5. [PMID: 11389048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
Chemotherapy of cancer is limited by its toxicity to normal cells. On the basis of discoveries in signal transduction and cell cycle regulation, novel mechanism-based therapeutics are being developed. Although these cell cycle modulators were designed to target cancer cells, some of them can also be applied for a different purpose, i.e., to protect normal cells against the lethality of chemotherapy. Loss of sensitivity of cancer cells to cell cycle inhibitors can be exploited for selective protection of normal cells that retain this response. Indeed, inhibition of redundant or overactivated pathways (e.g., growth factor-activated pathways) or stimulation of absent pathways in cancer cells (e.g., p53, Rb, and p16) may not arrest cycling of cancer cells. But growth arrest of normal cells will then permit selective killing of cancer cells by cycle-dependent chemotherapy.
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Affiliation(s)
- M V Blagosklonny
- Medicine Branch, National Cancer Institute, NIH, Bethesda, MD 20892, USA.
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Blagosklonny MV, Dixon SC, Robey R, Figg WD. Resistance to growth inhibitory and apoptotic effects of phorbol ester and UCN-01 in aggressive cancer cell lines. Int J Oncol 2001; 18:697-704. [PMID: 11251163 DOI: 10.3892/ijo.18.4.697] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
7-Hydroxystaurosporine (UCN-01), a non-selective inhibitor of protein kinase C (PKC), and phorbol ester (PMA), a PKC activator, are undergoing clinical evaluations. We investigated the effects of UCN-01 and PMA on a panel of prostate cancer cell lines. While PMA induced p21WAF1/CIP1 and arrest growth of LNCaP cancer cells (IC50 = 0.5-1 nM), aggressive cancer cell lines (DU145, PC3, and PC3M) were resistant to PMA (IC50 >5000 nM). Low concentrations (25-50 nM) of UCN-01 abrogated PMA-induced p21 and growth arrest in LNCaP cells. These low doses of UCN-01 however did not inhibit proliferation of any prostate cancer cell line. PMA-sensitive LNCaP cells were resistant to clinically relevant concentrations of UCN-01 (IC50 = 1.2 microM), but UCN-01 inhibited growth of DU145 and PC3/3M with an IC50 of 200-400 nM. For comparison, PMA-sensitive HL60 leukemia cells were sensitive to UCN-01 due to rapid apoptosis caused by UCN-01. In PMA-resistant prostate cancer cells, UCN-01 downregulated cyclin D1, induced p21, caused morphological differentiation, and G1-phase arrest leading to slow cell death without caspase activation. Importantly, normal prostate epithelial cells (PrEC) were very sensitive to both PMA (IC50 = 0.2 nM) and UCN-01. In PrEC, UCN-01 downregulated cyclin D1 and arrest growth with an IC50 less than 100 nM. We conclude that loss of sensitivity to either UCN-01 or PMA accompanies progression of prostate cancer.
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Affiliation(s)
- M V Blagosklonny
- Medicine Branch, Division of Clinical Sciences, National Cancer Institute, NIH, Bldg 10, 12N226, Bethesda, MD 20892, USA.
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Nicoletti MI, Myers TG, Fojo T, Blagosklonny MV. Wild-type p53 marginally induces endogenous MDR-1 mRNA without causing a measurable drug resistance in human cancer cells. Int J Oncol 2001; 18:375-81. [PMID: 11172607 DOI: 10.3892/ijo.18.2.375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The notion that wt p53 downregulates MDR-1 links p53 mutations to multidrug resistant phenotype. Alternatively, it has been envisioned that wt p53 protects cells against DNA damaging drugs by inducing MDR-1. Opposing conclusions on the relationship between MDR-1 and p53 have been predominantly based on the effects of p53 on MDR-1 promoter-constructs. We found that introduction of wt p53 slightly induced MDR-1 mRNA in three cell lines having endogenous mt p53. Wt p53-mediated induction of endogenous MDR-1 may represent a rudiment of cellular protection against toxic compounds earlier in evolution. Marked induction of p21WAF1/CIP1 (p21) mRNA was observed in all cell lines; and lower levels of wt p53 were required to induce p21 than MDR-1. Pgp was undetectable and wt p53 did not increase resistance to an MDR-1 substrate, suggesting the changes in MDR-1 mRNA may be functionally insignificant. Unlike endogenous MDR-1, the expression of an MDR-1 promoter (-434/+147 fragment) - luciferase construct was unchanged or even inhibited by wt p53 that may be secondary to wt p53-mediated cytotoxicity. Thus, partial promoter constructs may not accurately represent endogenous MDR-1.
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Affiliation(s)
- M I Nicoletti
- Medicine Branch and Developmental Therapeutics Program, National Cancer Institute, NIH, Bethesda, MD 20892, USA
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Blagosklonny MV. Do VHL and HIF-1 mirror p53 and Mdm-2? Degradation-transactivation loops of oncoproteins and tumor suppressors. Oncogene 2001; 20:395-8. [PMID: 11313969 DOI: 10.1038/sj.onc.1204055] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2000] [Revised: 10/23/2000] [Accepted: 10/23/2000] [Indexed: 11/08/2022]
Abstract
Recently it has been shown that the VHL tumor suppressor targets the hypoxia-inducible transcription factor (HIF-1) for ubiquitin-dependent degradation by the proteasome. Past mysteries of the p53 tumor suppressor help to solve the present puzzles of the VHL tumor suppressor. Thus, Mdm-2 targets the p53 tumor suppressor for ubiquitin-dependent degradation by the proteasome, but, in addition, the p53 transcription factor induces Mdm-2, thus, establishing a feedback loop. Hypoxia or DNA damage by abrogating binding of HIF-1 with VHL and p53 with Mdm-2, respectively, leads to stabilization and accumulation transcriptionally active HIF-1 and p53. More detailed analysis depicts the VHL/HIF-1 pair as the p53/mdm-2 pair that is turned upside down, suggesting that VHL may be a HIF-1-inducible gene of the feedback loop. The extended model proposes that an oncoprotein and a tumor suppressor due to transactivation coupled with feedback protein degradation might form functional pairs (Rb/E7, E2F/Rb, E2F/Mdm-2, catenin/APC, p27, cyclin D1, Rb/gankyrin), thus, predicting missing links.
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Affiliation(s)
- M V Blagosklonny
- Medicine Branch, National Cancer Institute, NIH, Bethesda, Maryland, MD 20892, USA
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Kim JS, Pirnia F, Choi YH, Nguyen PM, Knepper B, Tsokos M, Schulte TW, Birrer MJ, Blagosklonny MV, Schaefer O, Mushinski JF, Trepel JB. Lovastatin induces apoptosis in a primitive neuroectodermal tumor cell line in association with RB down-regulation and loss of the G1 checkpoint. Oncogene 2000; 19:6082-90. [PMID: 11146561 DOI: 10.1038/sj.onc.1204008] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
To develop a new approach to the treatment of primitive neuroectodermal tumors we evaluated the effect of the HMG-CoA reductase inhibitor lovastatin on the Ewing's sarcoma cell line CHP-100. Lovastatin induced neural morphology and markers including neuron-specific enolase and neurofilament protein. The acquisition of neural morphology required new mRNA synthesis, and cDNA microarray analysis confirmed that lovastatin altered the program of gene expression. After morphologic differentiation the cells underwent rapidly progressive apoptosis. In normal development of neuronal progenitors, differentiation signals trigger p21WAF1 accumulation, RB hypophosphorylation, enhanced RB-E2F-1 association, and G1 arrest, and these events have been shown to protect from apoptosis. In contrast, in the Ewing's sarcoma cells lovastatin triggered differentiation without causing cell cycle arrest: p21WAF1 was not induced, RB remained hyperphosphorylated, and RB protein expression and RB-E2F-1 association were markedly downregulated, suggesting that loss of an RB-regulated G1 checkpoint promoted apoptosis. Consistent with this hypothesis, adenoviral p21WAF1 decreased DNA synthesis and partially protected from lovastatin-induced cytotoxicity. The data demonstrate a new model for examining the genetic regulation of cell fate in a neural progenitor tumor and suggest a new approach to the treatment of this neoplasm.
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Affiliation(s)
- J S Kim
- Medicine Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, MD 20892, USA
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Salnikow K, Costa M, Figg WD, Blagosklonny MV. Hyperinducibility of hypoxia-responsive genes without p53/p21-dependent checkpoint in aggressive prostate cancer. Cancer Res 2000; 60:5630-4. [PMID: 11059752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
Hypoxia limits tumor growth but selects for higher metastatic potential. We tested the functional activity of hypoxia-inducible factor-1 (HIF-1) in prostate cell lines ranging from normal epithelial cells (PrEC), hormone-dependent LNCaP, hormone-independent DU145, PC-3 to highly metastatic PC-3M cancer cell lines. We found that HIF-1-stimulated transcription was the lowest in PrEC and LNCaP cells and the highest in PC-3M cells. The induction by hypoxia of the HIF-1 dependent genes Cap43 and GAPDH was the highest in the most aggressive PC-3M cancer cells. Because these advanced prostate cancer cell lines have lost p53 function, this further shifts a balance from p53 to HIF-1 transcriptional regulation, and a high ratio of HIF-1-dependent:p53-dependent transcription was a marker of the advanced malignant phenotype. Transient transfection of HIF-1alpha expression vector induced transcription from p21 promoter construct in prostate cancer cell lines. Furthermore, hypoxia slightly induced p21 mRNA in these cells. However, neither expression of p21 nor hypoxia caused growth arrest in PC-3M cells. Therefore, high inducibility of HIF-1-dependent genes, loss of p53 functions with high ratio of HIF-1-dependent:p53-dependent transcription, and loss of sensitivity to p21 inhibition is a part of hypoxic phenotype associated with aggressive cancer behavior.
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Affiliation(s)
- K Salnikow
- Nelson Institute of Environmental Medicine, and Kaplan Comprehensive Cancer Center, New York University School of Medicine, New York 10016, USA.
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Giannakakou P, Sackett DL, Ward Y, Webster KR, Blagosklonny MV, Fojo T. p53 is associated with cellular microtubules and is transported to the nucleus by dynein. Nat Cell Biol 2000; 2:709-17. [PMID: 11025661 DOI: 10.1038/35036335] [Citation(s) in RCA: 291] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Here we show that p53 protein is physically associated with tubulin in vivo and in vitro, and that it localizes to cellular microtubules. Treatment with vincristine or paclitaxel before DNA-damage or before leptomycin B treatment reduces nuclear accumulation of p53 and expression of mdm2 and p21. Overexpression of dynamitin or microinjection of anti-dynein antibody before DNA damage abrogates nuclear accumulation of p53. Our results indicate that transport of p53 along microtubules is dynein-dependent. The first 25 amino acids of p53 contain the residues that are essential for binding to microtubules. We propose that functional microtubules and the dynein motor protein participate in transport of p53 and facilitate its accumulation in the nucleus after DNA damage.
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Affiliation(s)
- P Giannakakou
- Medicine Branch, Division of Clinical Sciences, National Cancer Institute, National Institutes of Health, 9000 Rockville Pike, Bethesda, Maryland 20892, USA
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Abstract
Increasing the complexity of their models, p53s are stabilized either in order to function (wt p53) or due to the loss of function (mutant p53) with acquiring a mysterious prion-like ability to drive the normal p53 into the abnormal conformation to gain new functions. As already recognized, the loss of trans-activating function leads to a stabilization of mutant p53 because of the disappearance of the p53-inducible proteins, which otherwise directly (Mdm-2) or indirectly (p21) target p53 for degradation. Simplifying further, I will discuss that the loss of function results in a dominant-negative effect and gain-of-function (a dominant-positive effect). Thus, mutant p53 lacking trans-activation function nevertheless may retain the ability to repress transcription due to its competition with numerous transcription factors for their coactivators. When mutant p53 competes with wt p53, the inhibition of the wt p53-dependent transcription is perceived as a dominant-negative effect. Just like trans-repression, a dominant-negative effect requires an excess of p53 and, therefore, a 'dominant'-negative effect is not dominant. Furthermore, the stabilization of an endogenous mt p53 due to the loss of wt functions cannot occur in the presence of the wt p53 allele. Given the inability of mutant p53 to accumulate in the presence of wt p53, a dominant-negative effect does not naturally occur and, not surprisingly, heterozygous mt/wt cells are rare. The detection of a dominant-negative effect simply indicates that mutant p53 indeed has lost its function. Last, since mutant p53 loses some or most but not all activities and accumulates in the absence of wt allele, gain-of-function can be considered as an exaggeration of the remaining functions. Applications to cancer therapy are discussed. -Blagosklonny, M. V. p53 from complexity to simplicity: mutant p53 stabilization, gain-of-function, and dominant-negative effect.
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Affiliation(s)
- M V Blagosklonny
- Medicine Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA.
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Sandor V, Senderowicz A, Mertins S, Sackett D, Sausville E, Blagosklonny MV, Bates SE. P21-dependent g(1)arrest with downregulation of cyclin D1 and upregulation of cyclin E by the histone deacetylase inhibitor FR901228. Br J Cancer 2000; 83:817-25. [PMID: 10952788 PMCID: PMC2363539 DOI: 10.1054/bjoc.2000.1327] [Citation(s) in RCA: 226] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Depsipeptide, FR901228, a novel cyclic peptide inhibitor of histone deacetylase with a unique cytotoxicity profile is currently in phase I clinical trials. Here we demonstrate that, in addition to G2/M arrest, FR901228 causes G1 arrest with Rb hypophosphorylation. In vitro kinase assays demonstrated no direct inhibition of CDK activity, however, an inhibition was observed in CDKs extracted from cells exposed to FR901228. Cyclin D1 protein disappeared between 6 and 12 hours after treatment with FR901228, whereas cyclin E was upregulated. While it did not induce wt p53, FR901228 did induce p21(WAF1/CIP1)in a p53-independent manner. Cell clones lacking p21 were not arrested in G1 phase, but continued DNA synthesis and were arrested in G2/M phase following FR901228 treatment. Finally, FR901228 blunted ERK-2/MAPK activation by EGF whereas early signal transduction events remained intact since overall cellular tyrosine phosphorylation after EGF stimulation was unaffected. Thus, FR901228, while not directly inhibiting kinase activity, causes cyclin D1 downregulation and a p53-independent p21 induction, leading to inhibition of CDK and dephosphorylation of Rb resulting in growth arrest in the early G1 phase. In contrast to the G1 arrest, the G2/M arrest is p21-independent, but is associated with significant cytotoxicity.
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Affiliation(s)
- V Sandor
- Medicine Branch, DSC, NCI, NIH, Bethesda, MD 20892, USA
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Abstract
Though the term apoptosis was originated in pathology and developmental biology as an alternative to necrosis, the tissue necrosis with inflammation is irrelevant to cell culture conditions where apoptosis is mostly studied. Furthermore, no one single morphological feature is either necessary or sufficient to define apoptosis. The emerging biochemical definition, a cell death with caspase activation, allows the distinction of alternative forms of cell death. Thus, inhibition of caspases delays but does not prevent cell death. Slow cell death without caspase activation may nevertheless be associated with DNA fragmentation. Oncogenic Ras, Raf, and mitogen-activated kinases inhibit apoptosis by affecting the cytochrome C/caspase-9 pathway but may arrest growth and cause slow cell death with delayed DNA fragmentation. Such 'slow' cell death without caspase activation is often caused by chemotherapeutic drugs. Whether a cell will undergo apoptosis or slow death depends not only on a chemotherapeutic agent but also on the readiness of cellular caspases. Therefore, one can distinguish apoptosis-prone (eg leukemia) vs apoptosis-resistant cells. Cell susceptibilities to spontaneous, starvation-induced and drug-induced apoptosis are correlated and characterize an apoptosis-prone phenotype. Finally, distinction of slow cell death allows rephrasing of a question regarding the goal of cancer therapy: apoptosis vs slow cell death, or cancer cell-selectivity regardless of the mode of cell death.
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Affiliation(s)
- M V Blagosklonny
- Medicine Branch, National Cancer Institute, NIH, Bethesda, MD 20892, USA
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An WG, Hwang SG, Trepel JB, Blagosklonny MV. Protease inhibitor-induced apoptosis: accumulation of wt p53, p21WAF1/CIP1, and induction of apoptosis are independent markers of proteasome inhibition. Leukemia 2000; 14:1276-83. [PMID: 10914553 DOI: 10.1038/sj.leu.2401812] [Citation(s) in RCA: 163] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Inhibitors of proteases are currently emerging as a potential anti-cancer modality. Nonselective protease inhibitors are cytotoxic to leukemia and cancer cell lines and we found that this cytotoxicity is correlated with their potency as inhibitors of the proteasome but not as inhibitors of calpain and cathepsin. Highly selective inhibitors of the proteasome were more cytotoxic and fast-acting than less selective inhibitors (PS341>>ALLN>>ALLM). Induction of wt p53 correlated with inhibition of the proteasome and antiproliferative effect in MCF7, a breast cancer cell line, which was resistant to apoptosis caused by proteasome inhibitors. In contrast, inhibitors of the proteasome induced apoptosis in four leukemia cell lines lacking wt p53. The order of sensitivity of leukemia cells was: Jurkat>HL60> or =U937>>K562. The highly selective proteasome inhibitor PS-341 induced cell death with an IC50 as low as 5 nM in apoptosis-prone leukemia cells. Cell death was preceded by p21WAF1/CIP1 accumulation, an alternative marker of proteasome inhibition, and by cleavage of PARP and Rb proteins and nuclear fragmentation. Inhibition of caspases abrogated PARP cleavage and nuclear fragmentation and delayed, but did not completely prevent cell death caused by PS-341. Reintroduction of wt p53 into p53-null PC3 prostate carcinoma cells did not increase their sensitivity to proteasome inhibitors. Likewise, comparison of parental and p21-deficient cells demonstrated that p21WAF1/CIP1 was dispensable for proteasome inhibitor-induced cytotoxicity. We conclude that accumulation of wt p53 and induction of apoptosis are independent markers of proteasome inhibition.
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Affiliation(s)
- W G An
- Medicine Branch, National Cancer Institute, NIH, Bethesda, MD 20892, USA
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Salnikow K, Su W, Blagosklonny MV, Costa M. Carcinogenic metals induce hypoxia-inducible factor-stimulated transcription by reactive oxygen species-independent mechanism. Cancer Res 2000; 60:3375-8. [PMID: 10910041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Nickel (Ni2+) and cobalt (Co2+) mimic hypoxia and were used as a tool to study the role of oxygen sensing and signaling cascades in the regulation of hypoxia-inducible gene expression. These metals can produce oxidative stress; therefore, it was conceivable that reactive oxygen species (ROS) may trigger signaling pathways resulting in the activation of the hypoxia-inducible factor (HIF)-1 transcription factor and up-regulation of hypoxia-related genes. We found that the exposure of A549 cells to Co2+ or Ni2+ produced oxidative stress, and although Co2+ was a more potent producer of ROS than Ni2+, both metals equally increased the expression of Cap43, a hypoxia-regulated gene. The coadministration of hydrogen peroxide with metals induced more ROS; however, this did not further increase the expression of Cap43 mRNA. The free radical scavenger 2-mercaptoethanol completely suppressed ROS generation by CoCl2 and NiCl2 but did not diminish the induced Cap43 gene expression. The activity of the HIF-1 transcription factor as assessed in transient transfection assays was stimulated by Ni2+, hypoxia, and desferrioxamine, but this activation was not diminished when oxidative stress was attenuated nor was HIF-dependent transcription enhanced by hydrogen peroxide. We conclude that ROS are produced during the exposure of cells to metals that mimic hypoxia, but the formation of ROS was not involved in the activation of HIF-1-dependent genes.
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Affiliation(s)
- K Salnikow
- Nelson Institute of Environmental Medicine and Kaplan Comprehensive Cancer Center, New York University School of Medicine, New York 10016, USA.
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Blagosklonny MV, Bishop PC, Robey R, Fojo T, Bates SE. Loss of cell cycle control allows selective microtubule-active drug-induced Bcl-2 phosphorylation and cytotoxicity in autonomous cancer cells. Cancer Res 2000; 60:3425-8. [PMID: 10910051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Lack of selectivity in the killing of tumor and normal cells is a major obstacle in cancer therapy. By inhibiting normal but not autonomous cell growth, we exploited the differences in cell cycle regulation to achieve a selective protection of nonautonomous cells against paclitaxel and other microtubule-active drugs. Tubulin polymerization, a primary effect of paclitaxel, can be dissociated from Bcl-2 phosphorylation and cytotoxicity in HL-60 cells. Growth arrest prevented paclitaxel-induced Bcl-2 phosphorylation and apoptosis without affecting paclitaxel-induced tubulin polymerization. We abrogated the effects of paclitaxel on MCF-10A immortalized breast cells, while preserving its effects on MCF-7 cancer cells. Unlike MCF-7 cells, MCF-10A cells were arrested by epidermal growth factor withdrawal, precluding paclitaxel-induced Bcl-2 phosphorylation. Furthermore, the inhibition of the epidermal growth factor receptor kinase with low doses of AG1478 arrested growth of MCF-10A but not MCF-7 cells. Pretreatment with AG1478 did not affect paclitaxel-induced Bcl-2/Raf-1 phosphorylation in MCF-7 but abrogated such phosphorylation in MCF-10A. Exploitation of growth factor dependency may allow the protection of normal cells from microtubule-active drugs.
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Affiliation(s)
- M V Blagosklonny
- Medicine Branch, National Cancer Institute, NIH, Bethesda, Maryland 20892, USA.
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Giannakakou P, Poy G, Zhan Z, Knutsen T, Blagosklonny MV, Fojo T. Paclitaxel selects for mutant or pseudo-null p53 in drug resistance associated with tubulin mutations in human cancer. Oncogene 2000; 19:3078-85. [PMID: 10871860 DOI: 10.1038/sj.onc.1203642] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The efficacy of anticancer therapy is limited by the development of drug resistance. While the role of p53 in the intrinsic sensitivity of human cancer cells to paclitaxel (PTX) remains controversial, its role in acquired paclitaxel resistance has never been addressed. In this study we examined the p53 status of three paclitaxel selected human ovarian carcinoma sublines, resistant to paclitaxel due to acquired beta-tubulin mutations which impair paclitaxel's interaction with tubulin. In contrast to parental cells which have wt p53, in all PTX-resistant sublines p53 was functionally inactive. Two of the resistant sublines expressed high levels of transcriptionally inactive p53 protein, each with a distinct point mutation in codons 236 and 239 of the DNA binding domain. The third subline presented a novel p53 pseudo-null phenotype as a result of markedly decreased wt p53 mRNA expression. Introduction of ectopic wt p53 had no effect on PTX sensitivity in both parental and resistant cells, while it induced p21WAF1/CIP1, demonstrating an intact p53 pathway. While PTX resistance is primarily conferred by the tubulin mutations, the loss of functional p53 observed in all clones, suggests that this loss may facilitate the development of resistance potentially by providing a clonal advantage which promotes the isolation of paclitaxel resistant cells.
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Affiliation(s)
- P Giannakakou
- Medicine Branch, National Cancer Institute, NIH, Bethesda, Maryland, MD 20892, USA
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Kruger EA, Blagosklonny MV, Dixon SC, Figg WD. UCN-01, a protein kinase C inhibitor, inhibits endothelial cell proliferation and angiogenic hypoxic response. Invasion Metastasis 2000; 18:209-18. [PMID: 10640907 DOI: 10.1159/000024514] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Angiogenesis is required for tumor formation and growth; inhibition of angiogenesis is a promising new approach in cancer therapy. UCN-01, a protein kinase C (PKC) inhibitor, induces growth arrest and apoptosis in cancer cells and was recently introduced in a phase I clinical trial. We demonstrate that UCN-01, at concentrations lower than those necessary to inhibit cancer cell growth, inhibit proliferation of human endothelial cells in vitro. Moreover, UCN-01, at concentrations as low as 32 nM, prevent microvessel outgrowth from explant cultures of rat aortic rings. Since hypoxia activates hypoxia-inducible factor (HIF-1)-dependent transcription in cancer cells that, in a paracrine fashion, drive tumor angiogenesis, we investigated the effects of UCN-01 on HIF-1-responsive promoter constructs. We report that, in addition to direct inhibitory effects on endothelial cell growth, UCN-01 abrogates hypoxia-mediated transactivation of HIF-1-responsive promoters in a prostate cancer cell line. We conclude that UCN-01, at clinically relevant concentrations, exerts an anti-neovascularization effect by blocking two important steps in vessel formation: (1) the response of cancer cells to hypoxia, and (2) endothelial cell proliferation.
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Affiliation(s)
- E A Kruger
- Medicine Branch, Division of Clinical Sciences, National Cancer Institute, NIH, Bethesda, MD., USA
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Blagosklonny MV, Dixon SC, Figg WD. Efficacy of microtubule-active drugs followed by ketoconazole in human metastatic prostate cancer cell lines. J Urol 2000; 163:1022-6. [PMID: 10688042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
PURPOSE Once a relapse occurs following primary endocrine treatment, metastatic prostate cancer is one of the most therapy-resistant human neoplasms. Ketoconazole is used for complete androgen deprivation, and recent data suggest it has direct activity against prostate cancer cells. MATERIALS AND METHODS LNCaP, DU145, and PC3 cells, human prostate cancer cell lines, and HL60, a human leukemia cell line, were lysed and soluble proteins were harvested. Cells were plated in 96-well flat bottom plates and then exposed to the pharmacological agents, ketoconazole, vinblastine and paclitaxel. DNA synthesis was monitored by 3H-thymidine incorporation. RESULTS We demonstrate that ketoconazole exerts a cytostatic effect on a panel of human prostate cancer cell lines, with IC50 of 4 to 5 microg./ml., 12 microg./ml., and 25 microg./ml. for LNCaP, PC3/PC3M, and DU145 cells, respectively. On the other hand, using microtubule-active drugs, vinblastine and paclitaxel, we found that PC3M and PC3 cells were more resistant than either DU145 or LNCaP cells. This resistance was associated with a lesser degree of Raf-1 and Bcl-2 phosphorylation following exposure to microtubule-active drugs. Combinations of microtubule-active drugs with ketoconazole were a beneficial treatment in DU145 cancer cells. Furthermore, ketoconazole blocked recovery of all the prostate cancer cell lines following 24 hours-pulse treatment with vinblastine. CONCLUSION Pulse-administration of vinblastine followed by continuous administration of ketoconazole warrants investigation in the treatment of hormone-independent metastatic prostate cancer.
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Affiliation(s)
- M V Blagosklonny
- Medicine Branch, Division of Clinical Sciences, National Cancer Institute, NIH, Bethesda, Maryland 20892, USA
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Blagosklonny MV, Robey R, Bates S, Fojo T. Pretreatment with DNA-damaging agents permits selective killing of checkpoint-deficient cells by microtubule-active drugs. J Clin Invest 2000; 105:533-9. [PMID: 10683383 PMCID: PMC289166 DOI: 10.1172/jci8625] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Cell-cycle checkpoint mechanisms, including the p53- and p21-dependent G(2) arrest that follows DNA damage, are often lost during tumorigenesis. We have exploited the ability of DNA-damaging drugs to elicit this checkpoint, and we show here that such treatment allows microtubule drugs, which cause cell death secondary to mitotic arrest, to kill checkpoint-deficient tumor cells while sparing checkpoint-competent cells. Low doses of the DNA-damaging drug doxorubicin cause predominantly G(2) arrest without killing HCT116 cells that harbor wt p53. Doxorubicin treatment prevented mitotic arrest, Bcl-2 phosphorylation, and cell death caused by paclitaxel, epothilones, and vinblastine. In contrast, doxorubicin enhanced cytotoxicity of FR901228, an agent that does not affect microtubules. Low doses of doxorubicin did not arrest p21-deficient clones of HCT116 cells and did not protect these cells from cytotoxicity caused by microtubule drugs, but cells in which p21 expression was restored enjoyed partial protection under these conditions. Moreover, in p53-deficient clones of HCT116 cells doxorubicin did not induce either p53 or p21 and provided no protection against paclitaxel-induced cytotoxicity. Therefore, (a) p53-dependent p21 induction caused by doxorubicin protects from microtubule drug-induced cytotoxicity, and (b) pretreatment with cytostatic doses of DNA-damaging drugs before treatment with microtubule drugs results in selective cytotoxicity to cancer cells with defective p53/p21-dependent checkpoint.
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Affiliation(s)
- M V Blagosklonny
- Medicine Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA.
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Salnikow K, Blagosklonny MV, Ryan H, Johnson R, Costa M. Carcinogenic nickel induces genes involved with hypoxic stress. Cancer Res 2000; 60:38-41. [PMID: 10646848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
Carcinogenic nickel compounds alter the program of gene expression in normal cells and induce a pattern of gene expression similar to that found in nickel-induced cancers. Here we have demonstrated that nickel exposure induced hypoxic signaling pathways by inducing hypoxia-inducible transcription factor-1 (HIF-1), which mediated the induction of genes required by cells to survive hypoxia. We also show that a new gene, Cap43, is dependent upon HIF-1 because only HIF-1-proficient cells induced Cap43 when exposed to either hypoxia or nickel. We also show that glyceraldehyde-3-phosphate dehydrogenase, a gene induced by hypoxia through HIF-1, was similar to Cap43 in that it required HIF-1-proficient cells to be induced by either nickel or hypoxia. These data demonstrate that nickel exposure turns on signaling for hypoxic stress, which may be important in its carcinogenesis.
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Affiliation(s)
- K Salnikow
- Nelson Institute of Environmental Medicine, and Kaplan Comprehensive Cancer Center, New York University School of Medicine, New York 10016, USA.
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Abstract
Drug resistance is a well recognized problem in cancer therapy. Despite the current dogma that drug resistance is always an obstacle for treatment, here I show that it provides opportunities for selective protection of non-resistant cells with killing of drug-resistant cancer cells. According to the proposed 'two-drug' strategy, the first drug should be ineffective against a target drug-resistant cell (ie the drug is a substrate of MRP or Pgp pumps). In addition, it must be cytostatic but not cytotoxic. The second drug, which is applied in sequence, must be a cycle-dependent apoptotic drug to which the target cell is not cross-resistant. Thus, low doses of adriamycin, etoposide and actinomycin D, used as the first drugs, were cytostatic to parental HL60 cells. Therefore, these drugs precluded Bcl-2/Raf-1 phosphorylation, PARP cleavage and cell death which are otherwise induced by paclitaxel, a mitosis-selective apoptotic drug for HL60 cells. In contrast, HL60/ADR cells which express MRP, a transporter which pumps out the first drugs from a cell, were insensitive to the first drugs and therefore readily underwent apoptosis following the second drug. This strategy also allowed a selective killing of HL60/TX cells which express MDR-1, with the only difference being that the second drug, paclitaxel, was substituted for epothilones, non-Pgp substrates. Lack of protection by the first drug, a Pgp substrate, resulted in HL60/TX killing by the second drug, whereas parental HL-60 cells were fully protected. Therefore, drug resistant cells can be selectively killed by a combination of drugs not killing sensitive cells. Lack of toxicity against normal cells will be clinically translated in reduction of adverse side-effects of chemotherapy against drug-resistant malignancies.
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Affiliation(s)
- M V Blagosklonny
- Medicine Branch, National Cancer Institute, Building 10, R 12N226, NIH, Bethesda, MD 20892, USA
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Blagosklonny MV, An WG, Melillo G, Nguyen P, Trepel JB, Neckers LM. Regulation of BRCA1 by protein degradation. Oncogene 1999; 18:6460-8. [PMID: 10597248 DOI: 10.1038/sj.onc.1203068] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/1999] [Revised: 06/29/1999] [Accepted: 06/30/1999] [Indexed: 11/08/2022]
Abstract
BRCA1, a tumor suppressor protein implicated in hereditary forms of breast and ovarian cancer, is transcriptionally regulated in a proliferation-dependent manner. In this study, we demonstrate a substantial role for proteolysis in regulating the BRCA1 steady-state protein level in several cell lines. N-acetyl-leu-leu-norleucinal (ALLN), an inhibitor of the proteasome, calpain, and cathepsins, caused BRCA1 protein to accumulate in the nucleus of several human breast, prostate, and melanoma cell lines which express low or undetectable basal levels of BRCA1 protein, but not in cells with high basal expression of BRCA1. Protease inhibition did not increase BRCA1 synthesis, nor change its mRNA level, but it dramatically prolonged the protein's half-life. In contrast to ALLN, lactacystin and PS341, two specific proteasome inhibitors, as well as calpastatin peptide and PD150606, two selective calpain inhibitors, had no effect on BRCA1 stability, whereas ALLM, an effective calpain and cathepsin inhibitor but weak proteasome inhibitor, did stimulate accumulation of BRCA1. Moreover, three inhibitors of acidic cysteine proteases, chloroquine, ammonium chloride and bafilomycin, were as effective as ALLN. These results demonstrate that degradation by a cathepsin-like protease in fine balance with BRCA1 transcription is responsible for maintaining the low steady-state level of BRCA1 protein seen in many cancer cells.
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Affiliation(s)
- M V Blagosklonny
- Department of Therapeutics, National Cancer Institute, NIH, Bethesda, Maryland, MD 20892, USA
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Abstract
Recent studies on paclitaxel (Taxol), a microtubule-stabilizing agent and effective anti-cancer drug, have identified numerous cellular and molecular effects, such as induction of cytokines and tumor-suppressor genes, indirect cytotoxicity due to secretion of tumor necrosis factor, vast activation of signal-transduction pathways and selective activity against cells lacking functional p53. Some of these results, including the immediate activation of signaling pathways and gene expression, have been observed only with paclitaxel concentrations 1,000-fold higher than those required for mitotic arrest and apoptosis. The effects of loss of p53 on paclitaxel cytotoxicity depend on cell type (normal murine fibroblasts vs. human cancer cells) and duration of exposure to paclitaxel; p53 status marginally affects paclitaxel sensitivity in human cancer. Although the biochemistry of mitosis and meiosis has been studied independently of research on the mechanism of action of anti-cancer drugs, it eventually provided insight into the effects of paclitaxel. For example, serine protein phosphorylation, which occurs during mitotic arrest or meiosis, explains paclitaxel-induced hyperphosphorylation of Bcl-2 and Bcl-xL. Although some observations are disputed, such mitotic arrest correlates with paclitaxel cytotoxicity, while there is currently no evidence that any paclitaxel effect at clinically relevant concentrations is independent of its tubulin-binding properties. Thus, paclitaxel exerts two types of effect: mitotic arrest with coincidental serine protein phosphorylation and cytotoxicity at clinically relevant concentrations as well as immediate activation of tyrosine kinase pathways and activation of gene expression at much higher concentrations.
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Affiliation(s)
- M V Blagosklonny
- Medicine Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA.
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Salnikow K, An WG, Melillo G, Blagosklonny MV, Costa M. Nickel-induced transformation shifts the balance between HIF-1 and p53 transcription factors. Carcinogenesis 1999; 20:1819-23. [PMID: 10469629 DOI: 10.1093/carcin/20.9.1819] [Citation(s) in RCA: 96] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Nickel (Ni) compounds are potent carcinogens and can induce malignant transformation of rodent and human cells. In an attempt to unravel the molecular mechanisms of Ni-induced transformation we investigated transcriptional activity of hypoxia-inducible factor (HIF-1) and p53 tumor suppressor protein in Ni-transformed cells. We demonstrated that the activity of HIF-1-responsive promoters was increased in Ni-transformed rodent cells resulting in the increased ratio between HIF-1- and p53-stimulated transcription. To further elucidate the roles of HIF-1 and p53 in Ni-induced transformation we used human osteosarcoma (HOS) cells and a Ni-transformed derivative, SA-8 cells. Since non-functional p53 was expressed in both HOS and SA-8 cells, acute Ni treatment induced HIF-1alpha protein and HIF-1-dependent transcription without affecting p53. In MCF-7 and A549, human cancer cells with the wild-type p53, both functional p53 and HIF-1alpha proteins accumulated following exposure to Ni. The induction of HIF-1alpha and wild-type p53 by Ni was detected after 6 h and was most pronounced by 24 h. These results suggest that acute Ni treatment causes accumulation of HIF-1alpha protein and simultaneous accumulation of wild-type, but not mutant, p53. We suggest that the induction of hypoxia-like conditions in Ni-treated cells with subsequent selection for increased HIF-1-dependent transcription is involved in Ni-induced carcinogenesis.
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Affiliation(s)
- K Salnikow
- Nelson Institute of Environmental Medicine and Kaplan Comprehensive Cancer Center, New York University Medical Center, New York, NY 10016 USA.
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Bergan RC, Reed E, Myers CE, Headlee D, Brawley O, Cho HK, Figg WD, Tompkins A, Linehan WM, Kohler D, Steinberg SM, Blagosklonny MV. A Phase II study of high-dose tamoxifen in patients with hormone-refractory prostate cancer. Clin Cancer Res 1999; 5:2366-73. [PMID: 10499606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
Micromolar concentrations of tamoxifen inhibit the activity of protein kinase C and were recently shown to inhibit prostate cancer cell growth in preclinical studies. Because micromolar concentrations can be attained with high-dose therapy, the clinical activity of high-dose tamoxifen was evaluated in patients with metastatic adenocarcinoma of the prostate. Between December 1993 and February 1997, 30 patients with hormone-refractory metastatic adenocarcinoma of the prostate were continuously administered tamoxifen at 160 mg/m2/day. Therapy was continued until disease progression. All study patients had failed prior treatment with combined androgen blockade, had castrate levels of testosterone, and were heavily pretreated, having received a median of three prior regimens. The average steady-state plasma concentration of tamoxifen was 2.96+/-1.32 microM (mean +/- SD). Grade 3 neurotoxicity was observed in 29% of patients and was rapidly reversible and readily managed with dose modification. Otherwise, grade 3 toxicities were rare. One partial response (80% decline in prostate-specific antigen) was observed (3.3%), whereas disease stabilization was observed in six patients (20%), for a combined partial response/stable disease response rate of 23%. Median time to progression was 2.1 months, and median survival time was 10.5 months. High-dose tamoxifen therapy was well tolerated and associated with micromolar concentrations of tamoxifen in human plasma, and it demonstrated activity, albeit limited, in a heavily pretreated patient cohort with hormone-refractory prostate cancer. These findings suggest that further investigation of the role of protein kinase C modulation in prostate cancer is warranted.
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Affiliation(s)
- R C Bergan
- Medicine Branch, National Cancer Institute, Bethesda, Maryland 20892, USA
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