2015 Archived Content
Improper protein folding, a feature implicated in a host of pathologies including cancer, diabetes, autoimmune disease, and neurodegenerative disorders, leads to an accumulation of mis-folded proteins in the endoplasmic reticulum (ER). Under such cellular conditions, adaptation is achieved via the initiation of an integrated signal transduction pathway known as the Unfolded Protein Response (UPR), whereby specific transcriptional and translational mechanisms enable successful folding, modification and assembly of the unfolded protein load, or cell apoptosis. Recently, a number of strategies, chemical tools, and disease models have greatly enhanced our understanding of the underlying molecular machinery controlling the UPR, enabling small-molecule and gene targeting of specific UPR components. Modulating protein folding and homeostasis is emerging as a new and innovative therapeutic strategy.
Cambridge Healthtech Institute’s Inaugural Targeting the Unfolded Protein Response will gather an interdisciplinary collection of leaders working to advance the rapidly expanding field of UPR drug discovery.
Final Agenda
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Wednesday, September 23
11:30 am Registration
12:55 pm Plenary Keynote Program:
PLENARY KEYNOTE INTRODUCTION:
Comprehensive Kinase and Epigenetic Compound Profiling
Kelvin Lam, Ph.D., Director, Strategic Partnerships,
Reaction Biology Corporation
Kinase inhibitors can be used as chemical probes to understand signal transduction
pathways. Since the majority of kinase probes inhibit multiple kinases,
understanding the off-target effects will allow scientists to design better poly-pharmacologic
compounds to meet specific therapeutic needs. Profiling a compound against the entire
kinase gene family will allow us to understand the compound’s full enzymatic activities.
Unexpected activities could lead to different chemical design and possibly novel therapeutic
opportunities. Reaction Biology offers large-scale in vitro kinase and epigenetic profiling
services for (1) compound prioritizing and (2) elucidating novel activities for kinase and
epigenetic inhibitors.
PLENARY KEYNOTE SPEAKER:
iPS Cell Technology, Gene Editing and Disease Research
Rudolf Jaenisch, M.D., Founding Member, Whitehead Institute for Biomedical
Research; Professor, Department of Biology, Massachusetts Institute of
Technology
The development of the iPS cell technology has revolutionized our ability to study human
diseases in defined in vitro cell culture systems. A major problem of using iPS cells for this
“disease in the dish” approach is the choice of control cells because the unpredictable
variability between different iPS / ES cells to differentiate into a given lineage. Recently
developed efficient gene editing methods such as the CRISPR/Cas system allow the creation
of genetically defined models of monogenic as well as polygenic human disorders.
PLENARY KEYNOTE SPEAKER:
The Evolutionary Dynamics and Treatment of Cancer
Martin Nowak, Ph.D., M.Sc., Professor, Biology and Mathematics and Director,
Program for Evolutionary Dynamics, Harvard University
Cancer is an evolutionary process. Cancer initiation and progression are caused by
somatic mutation and selection of dividing cells. The mathematical theory of evolution can
therefore provide quantitative insights into human cancer.
2:40 Refreshment Break in the Exhibit Hall with Poster Viewing
3:25 Chairperson’s Opening Remarks
Claudio Hetz, Ph.D., Professor, Institute of Biomedical Sciences, University of Chile; Principal Investigator, Laboratory of Cellular Stress and Biomedicine, Adjunct Professor, School of Public Health, Harvard University
3:35 FEATURED PRESENTATION: The Unfolded Protein Response and Liver Failure
Randal J. Kaufman, Ph.D., Director, Degenerative Disease Research, Sanford Burnham Medical Research Medical Institute; Professor, Department of Pharmacology, University of California, San Diego; President and CEO, Kaufman Genetics, Inc.
The liver is the central organ in humans that regulates systemic lipid homeostasis. Hepatic lipid metabolism is intimately connected with the function of the endoplasmic reticulum (ER). Genetic deficiencies and environmental insults disrupt ER function to cause the accumulation of misfolded protein, a condition called ‘ER stress’ that can lead to inflammation. Hepatic ER stress can also cause non-alcoholic fatty liver disease (NAFLD) that may progress to non-alcoholic steatohepatitis (NASH) and eventually hepatocellular carcinoma (HCC). The unfolded protein response is an adaptive response designed to resolve protein misfolding in the ER that is signaled through three transmembrane sensors, primarily IRE1α, ATF6α, and PERK. If protein misfolding is not resolved, cells initiate apoptosis in a manner that requires PERK-mediated phosphorylation of eukaryotic initiation factor 2 (eIF2) on the alpha subunit to attenuate protein synthesis. Paradoxically, a number of mRNAs, including Atf4 mRNA, require eIF2α phosphorylation for efficient translation. ATF4 induces transcription of the C/EBP homologous protein CHOP. We have shown that ATF4 and CHOP act together to induce genes encoding ER chaperones, autophagy and translational machinery. As a consequence, forced expression of ATF4 and CHOP is sufficient to increase protein synthesis that leads to ATP depletion, oxidative stress, lipid accumulation, and cell death in the liver. We demonstrate that protein misfolding in the ER of hepatocytes causes cytosolic lipid accumulation due to defective trafficking of triglycerides into the ER lumen and disrupts triglyceride assembly to generate very low density lipoprotein (VLDL) particles, causing secretion of apoB-containing lipoproteins that are not sufficiently saturated with lipids. As a consequence, disruption of ER homeostasis leads to symptoms of NAFLD and NASH. In addition, protein misfolding in hepatocytes causes oxidative stress that may lead to oncogenic mutations to cause HCC. Each signaling subpathway of the UPR is required to provide a distinct and unique role to prevent lipid accumulation in the hepatocyte. It is the concerted action of the UPR that prevents progression of NAFLD to NASH and HCC.
4:05 Inhibiting the Terminal Unfolded Protein Response to Prevent Cell Degeneration
Scott André Oakes, M.D., Associate Professor, Pathology, University of California, San Francisco
The Oakes laboratory studies how mammalian cells sense and respond to protein-folding stress within the endoplasmic reticulum (ER) through an ancient signaling pathway called the Unfolded Protein Response (UPR), and what goes wrong with this process in diseases of cell loss (e.g., neurodegeneration, diabetes) and cell gain (e.g., cancer). With our longstanding collaborator Feroz Papa, we have designed rigorous in vitro assays and mouse models to identify and monitor the pro-survival and pro-death signals sent from the master UPR regulator IRE1a--an ER transmembrane kinase/RNase. Through building and testing a series of chemical-genetic IRE1a tools, our labs discovered that mammalian IRE1a has binary outputs that determine either homeostasis (Adaptive UPR) or apoptosis (Terminal UPR) dependent on the strength of upstream ER stress.
4:35 Selected Poster Presentation
5:05 Refreshment Break in the Exhibit Hall with Poster Viewing
5:40 Gene Therapy to Reset ER Proteostasis Alterations in Neurodegenerative Diseases
Claudio Hetz, Ph.D., Professor, Institute of Biomedical Sciences, University of Chile; Principal Investigator, Laboratory of Cellular Stress and Biomedicine, Adjunct Professor, School of Public Health, Harvard University
The most common neurodegenerative diseases, such as Alzheimer’s Disease, Parkinson’s Disease, and amyotrophic lateral sclerosis, affect millions of people worldwide, but there is neither preventive nor curative therapy for them. These diseases share a common neuropathology, primarily featuring the presence of abnormal protein inclusions containing specific misfolded proteins. Recent evidence indicates that alteration in organelle function is a common pathological feature of protein misfolding disorders. Endoplasmic reticulum (ER) proteostasis alterations have been extensively described in most experimental models of neurological disorders. To cope with ER stress, cells activate an integrated signaling response termed the Unfolded Protein Response (UPR), which aims to reestablish homeostasis or the induction of cell death programs to eliminate damaged cells. UPR transcription factors such as XBP1 orchestrates cellular adaptation by regulating genes involved in protein folding, quality control and degradation pathways. In this talk I overview our efforts to assess the role of ER stress in protein misfolding disorders, and discuss the development of UPR-based gene therapy approaches to restore ER proteostasis defects observed in neurodegenerative diseases.
6:10 Targeting the Unfolded Protein Response in Cancers
Eric Chevet, Ph.D., Senior Principal Scientist, French National Institute for Health Research (INSERM)
Growing evidences support the contribution of the Unfolded Protein Response to tumor growth. However the molecular mechanisms underlying remain poorly understood. We recently found that the endoplasmic reticulum stress sensor IRE1alpha was capable of selectively controlling cancer cell fate in vitro and in vivo through its endoribonuclease activity, mechanism named Regulated IRE1-Dependent mRNA Decay (RIDD). We demonstrated that RIDD activity controls cancer cell adaptation and tumor development. Indeed inhibition of IRE1alpha signaling prevented the degradation of select mRNAs, thereby sensitizing cells to stress, altering tumorigenesis and mouse survival following orthotopic implantation of glioblastoma cells. In contrast, silencing specific RIDD substrates components in IRE1alpha deficient cells restored select properties of tumor growth in vivo. Tumor analyses revealed that low RIDD substrate expression correlated with high IRE1alpha activity and poor patient survival. Thus, our data identified a novel mechanism connecting the Unfolded Protein Response with mRNA expression control through post-transcriptional regulation in tumor cells. This mechanism represents a novel target of therapeutic relevance whose efficacy was tested in glioblastoma as an example. We describe the importance of this interplay in cancer cell survival advantage and tumor development and we show that the pharmacological targeting of IRE1alpha might represent an efficient way to reduce glioblastoma tumor burden and recurrence.
6:40 Close of Day
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Thursday, September 24
7:30 am Registration
8:00 Interactive Breakfast Breakout Discussion Groups
This interactive session provides conference delegates and speakers an opportunity to choose a specific roundtable discussion group to join. Each group has a moderator to ensure focused discussions around key issues within the topic. This format allows participants to meet potential collaborators, share examples from their work, vet ideas with peers, and be part of a group problem-solving endeavor. The discussions provide an informal exchange of ideas and are not meant to be a corporate or specific product discussion.
Molecular and Cellular Activity of Chaperone Inhibitors
Moderator: Maureen Murphy, Ph.D., Professor and Program Leader, Molecular and Cellular Oncogenesis Program, The Wistar Institute
- What are common, and what are unique, client proteins for heat shock proteins?
- What are the common biological activities of inhibitors to heat shock proteins, such as effects on apoptosis, cell cycle arrest, autophagy, the proteasome, etc?
- What other diseases, other than cancer, might be targeted using chaperone inhibitors?
Challenges Surrounding Targeting the UPR
Moderator: Scott André Oakes, M.D., Associate Professor, Pathology, University of California, San Francisco
- What are the most likely side effects of inhibiting the UPR?
- What are the best ways to quantifiably measure UPR activation status in human tissues?
8:45 Chairperson’s Remarks
Randal J. Kaufman, Ph.D., Director, Degenerative Disease Research, Sanford Burnham Medical Research Medical Institute; Professor, Department of Pharmacology, University of California, San Diego; President and CEO, Kaufman Genetics, Inc.
8:55 Discovery of Novel Allosteric IRE1a Inhibitors
Dai-Shi Su, Ph.D., Manager, Medicinal Chemistry, Oncology, GlaxoSmithKline
The IRE1a/XBP1 pathway has been implicated in tumor cell survival under stress conditions. XBP1 has been shown to be overexpressed in a variety of human cancers. Activation of IRE1a can also lead to the induction of apoptosis. These data suggest the utility of targeting the IRE1a/XBP1 pathway as a potential anticancer therapy. This presentation will report the discovery of diazospirodecanes as potent and selective allosteric IRE1a inhibitors. Elucidation of the structure-activity relationship of the structurally novel high-throughput screening (HTS) lead provided potent and selective IRE1a inhibitors. The SAR optimization, first co-crystal structure of a small molecule inhibitor, GSK2850163A, with human IRE1a, and mode of inhibition (MOI) characterization of compounds will also be discussed in the presentation.
9:25 Small Molecule Inhibitors Targeting IRE1
Dustin Maly, Ph.D., Associate Professor and Raymon E. and Rosellen M. Lawton Distinguished Scholar in Chemistry, Department of Chemistry, University of Washington
I will discuss the development of a ATP-competitive IRE1 Kinase-Inhibiting RNase Attenuators-KIRAs-that allosterically inhibit IRE1’s RNase by breaking oligomers. One optimized KIRA, KIRA6, inhibits IRE1 in vivo and promotes cell survival under ER stress.
9:55 Discovery and Development of IRE1 inhibitors
Heather P. Harding, Ph.D., Scientist, Metabolic Research Laboratories and NIHR Cambridge Biomedical Research Centre, University of Cambridge
We report on the identification of a small molecule inhibitor that attains its selectivity by forming an unusually stable Schiff base with lysine 907 in the IRE1 endonuclease domain, explained by solvent inaccessibility of the imine bond in the enzyme-inhibitor complex.
10:25 Coffee Break in the Exhibit Hall with Poster Viewing and Poster Winner Announced
11:10 PERK Inhibitors and Translational Control in Neurodegeneration
Jeffrey M. Axten, Ph.D., Director, Medicinal Chemistry, Virtual Proof of Concept (VPoC) DPU, Alternative Discovery & Development, GlaxoSmithKline
The recent discovery that the PERK inhibitor GSK2606414 is neuroprotective in a mouse model of prion disease is a promising step toward validating the UPR as an attractive pathway for therapeutic intervention. Further evaluation of PERK inhibitors in various disease models is building a strong case for potential broad use to treat many neurodegenerative disorders. This talk will discuss the efficacy of PERK inhibitors in disease models, advances in our understanding of PERK inhibitor toxicity, as well as challenges and opportunities for future development.
11:40 Targeting the Unfolded Protein Response for Prevention of Neurodegeneration
Julie Moreno, Ph.D., Research Scientist, Department of Microbiology, Immunology & Pathology, Colorado State University
I will be discussing our work showing that accumulation of misfolded proteins, specifically prion protein (PrP) and a form of mutant tau associated with frontotemporal demenita, lead to neurodegeneration through sustained over-activation of the PERK/eIF2α branch of the UPR. These high levels of eIF2α-P are catastrophic for neurons, leading to neurodegeneration through repression of protein synthesis and the critical decline of key proteins. We have used both focal genetic manipulation and pharmacological inhibition of this pathway to restore protein synthesis rates, protecting against neuronal loss and restoring memory in prion-diseased mice, and in a mouse model of tauopathy using PERK inhibitor. Critically, the neuroprotection in both cases is found to be downstream of the misfolded pathogenic protein. Activation of the UPR has been identified in brains of patients with multiple neurodegenerative diseases including AD, PD, ALS and prion disease. Thus, targeting the UPR to restore protein synthesis rates in neurons is an attractive target for prevention of neurodegeneration in a range of age-related neurodegenerative diseases, irrespective of the disease specific misfolded protein.
12:10 pm Sponsored Presentation (Opportunity Available)
12:40 Session Break
12:50 Luncheon Presentation (Sponsorship Opportunity Available) or Lunch on Your Own
1:30 Refreshment Break in the Exhibit Hall with Poster Viewing
2:15 Chairperson’s Remarks
Eric Chevet, Ph.D., Senior Principal Scientist, French National Institute for Health Research (INSERM)
2:20 Antibody-Targeted Induction of UPR-Mediated Cell Death
Ulrich Brinkmann, Ph.D., Expert Scientist, Pharma Research & Early Development, Roche
We applied antibody-based targeting sysztems to deliver UPR-inducing compounds to tumor cells. This leads to specific induction of UPR in target cells and subsequent induction of apoptosis. We present these ADC-like entities with novel mode of cytotoxicity for cancer therapy. Preclinical work on this novel concept will be discussed.
2:50 Hsp90 Inhibitor Drug Conjugates (HDCs): Proof-of-Concept in Preclinical Studies
Weiwen Ying, Ph.D., Synta Fellow and Vice President, Discovery Chemistry, Synta Pharmaceuticals
One of the major challenges in cancer treatment is to selectively deliver oncology drugs directly to tumors, and thus spare normal tissues. One successful approach to meet this challenge is demonstrated by the development of Antibody Drug Conjugates (ADCs). It has been shown in human cancer patients and mouse xenografts that heat shock protein 90 (Hsp90) is overexpressed in tumors, and inhibitors of Hsp90 are preferentially retained in tumor tissue in contrast to their rapid clearance from normal tissues. We have developed a small-molecule drug conjugate platform technology using these unique properties of Hsp90 proteins and Hsp90 inhibitors. Hsp90-Inhibitor Drug Conjugates (HDCs) offer many of the advantages of antibody-driven targeted delivery with potentially broader applicability. Conjugates with various payloads such as topoisomerase inhibitors and proteasome inhibitors have been advanced into preclinical studies.
3:20 Session Break
3:30 Targeting Intrinsic Molecular Chaperones in Ultrarare, Protein Misfolding Diseases
Thomas Kirkegaard Jensen, Ph.D., CSO, Orphazyme
Intrinsic molecular chaperones form a tightly regulated, key homeostatic system, which is induced in response to a number of physiological and pathological stresses, such as protein misfolding and aggregation, endoplasmic reticulum stress, and oxidative stress. The components of this system have been shown to impact a number of degenerative diseases, including severe diseases of the nervous system, providing an attractive target for pharmaceutical intervention. In this presentation, I will describe the system and the translational and developmental considerations that has gone into the development of drugs targeting it, with a particular focus on a clinical-stage class of compounds known as chaperone co-inducers.
4:00 HSP70 as a Novel Therapeutic Target for Cancer
Maureen Murphy, Ph.D., Professor and Program Leader, Molecular and Cellular Oncogenesis Program, The Wistar Institute
In 2009 we identified the compound pifithrin mu (also phenylethynesulfonamide, or PES) as a selective inhibitor of the stress-inducible HSP70 protein. We next analyzed over four dozen PES derivatives, and identified PET-16 as one with nanomolar IC50 for tumor cells. We successfully co-crystallized PET-16 with the HSP70 ortholog DnaK, and showed that PET-16 binds to an allosterically regulated hinge region of this protein. We also showed that HSP70 inhibition leads to impaired proteasome function, HSP90 function, and autophagy, leading to cell death. In this presentation we will focus on the next two most pertinent questions in the HSP70 field: the identification of key HSP70 client proteins, and the pre-clinical efficacy of these inhibitors as anti-cancer agents. We have used proteomics to identify several novel HSP70 clients. We also show that PET-16 is a potent and efficacious inhibitor of melanoma progression and metastasis.
4:30 Discovery of TAS-116: A Novel Inhibitor of HSP90α and HSP90β
Shuichi Ohkubo, Ph.D., TAS-116 Early Development Team Chair, Taiho Pharmaceutical Co., Ltd.
The molecular chaperone heat shock protein 90 (HSP90) plays a crucial role in cancer cell growth and survival by stabilizing cancer-related proteins. Several HSP90 inhibitors have been developed and some have shown clinical activities in certain types of tumors; however, none are currently approved for any cancer indication. Here, we will review the development of HSP90 inhibitors and discuss the issues that have hampered their clinical development. We will then present our recent discovery of TAS-116, which is an orally available, highly selective inhibitor of HSP90α and HSP90β that is currently undergoing clinical trial, and discuss the therapeutic potential of TAS-116.
5:00 Close of Conference
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