Tạp chí khoa học số 2006-05-26

26 May 2006 | $10 PCR so reliable, we guarantee your results. Get successful PCR the first time with AccuPrime1 ™ enzymes and primers from Invitrogen. Put an end to waste: reduce rework, optimization, and repeat reactions. Start getting used to PCR you can count on. And if something goes wrong, we’ll troubleshoot it and make it right — even redesign and synthesize primers at no charge. See how dependable PCR can be at www.invitrogen.com/accuprime. © 2006 Invitrogen Corporation. All rights reserved. These products may be covered by one or more Limited Use Label Licenses (see the Invitrogen catalog or our website, www.invitrogen.com). LESS ASTE MORE BAND. 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Only StrataScript ® 5.0 RT delivers reliable results at any temperature. Choose the Temperature You Need Need More Information? Give Us A Call: Stratagene US and Canada Order: 800-424-5444 x3 Technical Service: 800-894-1304 x2 Stratagene Japan K.K. Order: 3-5821-8077 Technical Service: 3-5821-8076 www.stratagene.com Stratagene Europe Order: 00800-7000-7000 Technical Service: 00800-7400-7400 StrataScript ® is a registered trademark of Stratagene in the United States. SuperScript ® is a registered trademark of Invitrogen Corp. Patents pending. GE Healthcare When it comes to life sciences, GE Healthcare is setting the standard. Tens of thousands of scientists in over 100 countries around the world rely on our products every day. We have delivered more than 60 000 research protein purification systems, 1500 BioProcess ™ systems and 12 000 BioProcess columns worldwide. Our Amersham family of consumables, with its 60-year heritage, is trusted to provide accurate results time and time again. 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GE04-06 www.dowellstubbs.com www.sciencemag.org SCIENCE VOL 312 26 MAY 2006 1093 CONTENTS CONTENTS continued >> INTRODUCTION Celebrating a Glass Half-Full 1157 NEWS Energy Deregulation: Licensing Tumors to Grow 1158 Autophagy: Is It Cancer’s Friend or Foe? 1160 PERSPECTIVES The New Era in Cancer Research 1162 H. Varmus Poster: Cancer Treatment Gets Personal Cancer Biomarkers—An Invitation to the Table 1165 W. S. Dalton and S. H. Friend Molecular Imaging in Cancer 1168 R. Weissleder Antiangiogenic Therapy: A Universal Chemosensitization 1171 Strategy for Cancer? R. S. Kerbel Targeting Tyrosine Kinases in Cancer: The Second Wave 1175 J. Beselga SPECIAL SECTION Frontiers in Cancer Research Volume 312, Issue 5777 DEPARTMENTS 1099 Science Online 1101 This Week in Science 1107 Editors’ Choice 1110 Contact Science 1113 NetWatch 1115 Random Samples 1135 Newsmakers 1154 AAAS News & Notes 1233 New Products 1234 Science Careers COVER Advances in understanding the genetic basis of cancer have led to promising new therapies, which in turn have fueled discussions about a future model of cancer care in which treatment decisions are guided by the molecular attributes of the individual patient. A special section beginning on page 1157 examines this model and other emerging themes in cancer research. Image: J. Moglia/Science; photos, (top) Getty Images, (bottom) Royalty-Free/Corbis EDITORIAL 1105 Health Roundup by Donald Kennedy NEWS OF THE WEEK Synthetic Biologists Debate Policing Themselves 1116 Pakistan Gives Geology Conference the Cold Shoulder 1117 Senate Panel Backs Social Sciences at NSF 1117 NIH Wants Its Minority Programs to Train More 1119 Academic Researchers SCIENCESCOPE 1119 High-Tech Materials Could Render Objects Invisible 1120 >>Science Express reports by J. B. Pendry et al. and U. Leonhardt ‘Disappointed’ Butler Exhausts Appeals 1120 RNAi Safety Comes Under Scrutiny 1121 Price Crash Rattles Europe’s CO 2 Reduction Scheme 1123 NEWS FOCUS A Vision for the Blind 1124 Universities Find Too Many Strings Attached to 1127 Foundation’s Offer A Quiet Leader Unites Researchers in Drive for the 1128 Next Big Machine Why the International Linear Collider? The HapMap Gold Rush: Researchers Mine A Rich 1131 Deposit Who Can Read the Martian Clock? 1132 Bombardment Looking “Possible” For related online content, see page 1099 or go to: www.sciencemag.org/sciext/cancer/ 1124 Success with proteins — made possible by QIAGEN’s expertise! QIAGEN’s comprehensive protein portfolio will help you rise to the challenge of working with proteins. QIAGEN provides easy-to-use, integrated solutions to help you succeed with: ■ Expression ■ Purification ■ Detection ■ Assay ■ Crystallization ■ MALDI sample prep ■ Proteomics sample prep ■ Automation ■ Fractionation * Image shows E. coli gyrase A C-terminal domain crystals. Courtesy of Alex Ruthenburg from Prof. Verdine’s laboratory, Harvard University, Boston, USA. For up-to-date trademarks and disclaimers, see www.qiagen.com . PROTTAG0406S1WW © 2006 QIAGEN, all rights reserved. Systems Biology — Proteins and Proteomics Standardized solutions for proteins WWW.QIAGEN.COM Find a standardized solution for your protein challenge at www.qiagen.com/protein ! More reproducibility, streamlined crystallization* More proteins, purer, faster More peptide matches, more protein hits www.sciencemag.org SCIENCE VOL 312 26 MAY 2006 1095 CONTENTS continued >> SCIENCE EXPRESS www.sciencexpress.org BIOCHEMISTRY p53 Regulates Mitochondrial Respiration S. Matoba et al. Cancer cells can survive in low oxygen conditions because a defect in a common tumor suppressor inhibits mitochondrial respiration, allowing glycolysis to take place. 10.1126/science.1126863 MEDICINE Chimpanzee Reservoirs of Pandemic and Nonpandemic HIV-1 B. F. Keele et al. SIV, a close relative of the AIDS virus, infects up to 35 percent of the chimpanzees in a wild population in Cameroon, pointing to Pan t. troglodytes as the natural reser- voir of HIV-1. 10.1126/science.1126531 PHYSICS Controlling Electromagnetic Fields J. B. Pendry, D. Schurig, D. R. Smith The tunable dielectric and magnetic properties of metamaterials could be used in stealth technologies to cloak an object from view. >> News story p. 1120; Science Express article by U. Leonhardt 10.1126/science.1125907 Optical Conformal Mapping U. Leonhardt In theory, the tunable dielectric and magnetic properties of metamaterials could be used in stealth technologies to pass light completely around an object and cloak it from view. >> News story p. 1120; Science Express article by J. B. Pendry et al. 10.1126/science.1126493 CONTENTS LETTERS Scientific Description Can Imperil Species 1137 B. L. Stewart, A. G. J. Rhodin, L. L. Grismer, T. Hansel Tropical Deforestation and Global Warming P. M. Fearnside Concern About Gag Rules L. Pietrafesa Working Together for Communication D. Acosta Response D. Kennedy Revisiting the Age of the Sahara Desert S. Kroepelin; C. S. Swezey Response M. Schuster et al. BOOKS ET AL. Genesis The Scientific Quest for Life’s Origin 1140 R. M. Hazen, reviewed by I. Fry Browsings 1141 EDUCATION FORUM Planning Early for Careers in Science 1143 R. H. Tai, C. Q. Liu, A. V. Maltese, X. Fan PERSPECTIVES How Many Ways to Make a Chordate? 1145 P. Lemaire >> Research Article p. 1183 Was the Younger Dryas Triggered by a Flood? 1146 W. S. Broecker The Vacuum Energy Crisis 1148 A. Vilenkin >> Research Article p. 1180 High-Pressure Microscopy 1149 Z. Wang and Y. Zhao >> Report p. 1199 Bacteria Seize Control by Acetylating Host Problems 1150 C. A. Worby and J. E. Dixon >> Report p. 1211 Fluctuations in Plasticity at the Microscale 1151 M C. Miguel and S. Zapperi >> Report p. 1188 TECHNICAL COMMENT ABSTRACTS GEOCHEMISTRY Comment on “Heterogeneous Hadean Hafnium: 1139 Evidence of Continental Crust at 4.4 to 4.5 Ga” J. W. Valley, A. J. Cavosie, B. Fu, W. H. Peck, S. A. Wilde full text at www.sciencemag.org/cgi/content/full/312/5777/1139a Response to Comment on “Heterogeneous Hadean Hafnium: Evidence of Continental Crust at 4.4 to 4.5 Ga” T. M. Harrison et al. full text at www.sciencemag.org/cgi/content/full/312/5777/1139b BREVIA ATMOSPHERIC SCIENCE Enhanced Mid-Latitude Tropospheric Warming in 1179 Satellite Measurements Q. Fu, C. M. Johanson, J. M. Wallace, T. Reichler The pattern of tropospheric warming and stratospheric cooling visible in 26 years of satellite data indicates that the jet streams have been shifting poleward. RESEARCH ARTICLES ASTRONOMY Why the Cosmological Constant Is Small and Positive 1180 P. J. Steinhardt and N. Turok Models in which our universe repeatedly grows from a big bang and then collapse, produce a small cosmological constant consistently, not only as a special case. >> Perspective p. 1148 DEVELOPMENT Regulatory Blueprint for a Chordate Embryo 1183 K. S. Imai, M. Levine, N. Satoh, Y. Satou Sea squirts, among the simplest of extant chordates, now yield a glimpse at the network of regulatory gene interactions needed to gen- erate a chordate animal. >> Perspective p. 1145 Finnzymes Oy • Keilaranta 16 A, 02150 Espoo, Finland • Tel. +358 9 584 121 • Fax +358 9 5841 2200 • fz@finnzymes.fi • www.finnzymes.com Distributed in the US and Canada by New England Biolabs. For other countries visit www.finnzymes.com. PCR license notice: T hese products are sold under licensing arrangements of Finnzymes Oy with F. Hoffman-La Roche Ltd. The purchase of these products is accompanied by a limited license to use them in the P olymer ase Chain Reaction (PCR) process in conjunction with a thermal cycler whose use in the automated performance of the PCR process is covered by the up-front fee, either by payment to Applied Biosystems or as purc hased, i.e. an authorized thermal cycler. Finnzymes’ New Phusion ™ Hot Start The Number One DNA Polymerase Accuracy The highest fidelity of any available thermostable polymerase Speed Increased processivity allows reaction times to be reduced dramatically Specificity Reduces non-specific amplification and primer degradation Robustness Reduces reaction failures and minimizes optimization 1kb(GC-rich) 2kb 7.5 kb M P ABCP ABCP ABCM 7.5 kb 2.0 kb 1.0 kb (GC-rich) The following fragments were amplified from human genomic DNA: 1kb from CEBPB gene (GC-rich), 2 kb and 7.5 kb from human β-globin gene. Hot start high-fidelity DNA polymerases (P, A,B,C) were used according to suppliers’ recommendations: P) Phusion™ Hot Start High-Fidelity DNA Polymerase A) novel Pfu-based fusion DNA polymerase B) modified Pfu DNA polymerase C) T. kodakaraensis DNA polymerase Phusion - Extreme Performance www.sciencemag.org SCIENCE VOL 312 26 MAY 2006 1097 CONTENTS CONTENTS continued >> REPORTS MATERIALS SCIENCE Scale-Free Intermittent Flow in Crystal Plasticity 1188 D. M. Dimiduk, C. Woodward, R. LeSar, M. D. Uchic The relation between number and size of slip events in deforming nickel microcrystals follows a power law, like slip in ice and avalanches. >> Perspective p. 1151 APPLIED PHYSICS Electronic Confinement and Coherence in 1191 Patterned Epitaxial Graphene C. Berger et al. Thin graphene layers grown on silicon carbide can be patterned into ribbons that exhibit high electrical conductivity and quantum confinement effects at near zero kelvin. CHEMISTRY Imaging Bond Formation Between a Gold Atom 1196 and Pentacene on an Insulating Surface J. Repp, G. Meyer, S. Paavilainen, F. E. Olsson, M. Persson A scanning tunneling microscope is used to form, break, control, and image a single bond between a gold atom and an organic molecule adsorbed on an insulating layer. CHEMISTRY Carbon Nanotubes as High-Pressure Cylinders 1199 and Nanoextruders L. Sun et al. Induced defects on the walls of carbon nanotubes cause them to contract, producing a high-pressure chamber that can be probed with an electron microscope. >> Perspective p. 1149 GEOPHYSICS Earthquake Rupture Stalled by a Subducting 1203 Fracture Zone D. P. Robinson, S. Das, A. B. Watts In the great 2001 Peru earthquake, the rupture extended for 70 kilometers, skirted a barrier on the fault, then continued for another 200 kilometers, and 30 seconds later broke the barrier. GEOPHYSICS Reduced Radiative Conductivity of Low-Spin 1205 (Mg,Fe)O in the Lower Mantle A. F. Goncharov, V. V. Struzhkin, S. D. Jacobsen Measurements show that a spin-pairing transition in iron causes iron oxide minerals in the Earth to become more opaque at high pressure, likely altering heat transfer in the deep mantle. STRUCTURAL BIOLOGY Structure of the Eukaryotic Thiamine Pyrophosphate 1208 Riboswitch with Its Regulatory Ligand S. Thore, M. Leibundgut, N. Ban The structure of a common metabolite bound to a ubiquitous riboswitch shows how its ligand turns it off, suppressing translation of genes for the metabolite’s synthesis. SCIENCE (ISSN 0036-8075) is published weekly on Friday, except the last week in December, by the American Association for the Advancement of Science, 1200 New York Avenue, NW, Washington, DC 20005. Periodicals Mail postage (publication No. 484460) paid at Washington, DC, and additional mailing offices. Copyright © 2006 by the American Association for the Advancement of Science. The title SCIENCE is a registered trademark of the AAAS. Domestic individual membership and subscription (51 issues): $139 ($74 allocated to subscription). Domestic institutional subscription (51 issues): $650; Foreign postage extra: Mexico, Caribbean (surface mail) $55; other countries (air assist delivery) $85. First class, airmail, student, and emeritus rates on request. Canadian rates with GST available upon request, GST #1254 88122. Publications Mail Agreement Number 1069624. Printed in the U.S.A. Change of address: Allow 4 weeks, giving old and new addresses and 8-digit account number. Postmaster: Send change of address to AAAS, P.O. Box 96178, Washington, DC 20090–6178. Single-copy sales: $10.00 current issue, $15.00 back issue prepaid includes surface postage; bulk rates on request. Authorization to photocopy material for internal or personal use under circumstances not falling within the fair use provisions of the Copyright Act is granted by AAAS to libraries and other users registered with the Copyright Clearance Center (CCC) Transactional Reporting Service, provided that $18.00 per article is paid directly to CCC, 222 Rosewood Drive, Danvers, MA 01923. The identification code for Science is 0036-8075. Science is indexed in the Reader’s Guide to Periodical Literature and in several specialized indexes. MICROBIOLOGY Yersinia YopJ Acetylates and Inhibits Kinase 1211 Activation by Blocking Phosphorylation S. Mukherjee et al. The plague-causing bacterium inhibits the innate immune responses of its infected host by blocking the phosphorylation and activation of key signaling enzymes. >> Perspective p. 1150 MEDICINE A Regulatory SNP Causes a Human Genetic Disease 1215 by Creating a New Transcriptional Promoter M. De Gobbi et al. A type of anemia is caused by a change in a single nucleotide, creating a new promoterlike sequence that disrupts transcription of down- stream red blood cell genes. PLANT SCIENCE AXR4 Is Required for Localization of the 1218 Auxin Influx Facilitator AUX1 S. Dharmasiri et al. An intracellular protein directs a hormone transporter to a specific destination in the plant’s root that allows it to grow selectively downward in response to gravity. CELL BIOLOGY CRACM1 Is a Plasma Membrane Protein Essential 1220 for Store-Operated Ca 2+ Entry M. Vig et al. Two membrane proteins that control calcium flow into cells upon depletion of intracellular calcium stores are either part of the elusive calcium release–activated calcium channel or act as its regulators. DEVELOPMENTAL BIOLOGY Regulation of Adult Bone Mass by the Zinc Finger 1223 Adapter Protein Schnurri-3 D. C. Jones et al. A newly identified regulatory protein maintains the proper proportion of growing bones by controlling the degradation of a bone cell growth factor. MEDICINE Pituitary Adenoma Predisposition Caused by 1228 Germline Mutations in the AIP Gene O. Vierimaa et al. Molecular and genealogical data from a Finnish population show that benign but health-threatening tumors of the pituitary gland are caused by mutations in a regulatory gene. ECOLOGY Strong Top-Down Control in Southern California 1230 Kelp Forest Ecosystems B. S. Halpern, K. Cottenie, B. R. Broitman The community structure and biomass of California kelp forests are largely controlled by top-down factors such as predatory fish, rather than by levels of dissolved nutrients. 1151 & 1188 *Samples to qualified customers where available, while supplies last. ©2006 Promega Corporation. 14095-AD-MD New PureYield ™ plasmid preps deliver transfection-quality DNA in record time. Recover up to 1mg of plasmid DNA in less than 60 minutes (maxiprep) or up to 200μg in only 30 minutes (midiprep). No post-elution alcohol precipitation required. Race through your next plasmid prep. Request a FREE SAMPLE* at: www.promega.com/pureyield PROMEGA CORPORATION • www.promega.com 200 150 100 50 0 Minutes Leading Brand Time Required PureYield Midip r ep PureYield Maxip r ep Over 3 Hours Break the midiprep speed limit. and m axiprep \/ . bringing science to life and helping transform healthcare. We call it Life Science Re-imagined. Discover more at www.gehealthcare.com/life Bringing science to life GE Healthcare Bio-Sciences. Frontiers in Cancer Research Volume 312, Issue 5777 DEPARTMENTS 1099 Science Online 1101 This Week in Science 1107 Editors’ Choice 1110 Contact Science 1113 NetWatch 1115 Random Samples 1135. faster More peptide matches, more protein hits www.sciencemag.org SCIENCE VOL 312 26 MAY 2006 1095 CONTENTS continued >> SCIENCE EXPRESS www.sciencexpress.org BIOCHEMISTRY p53 Regulates Mitochondrial