Guy Salvesen earned his PhD in biochemistry from Cambridge University in 1980. He conducted postdoctoral research at Strangeways Laboratory and MRC Laboratory of Molecular Biology in Cambridge, followed by further post-doctoral training at the University of Georgia. In 1991 he was appointed Assistant Professor at Duke University. Dr. Salvesen was recruited to Sanford-Burnham Medical Research Institute in 1996, where he is professor and director of the Apoptosis and Cell Death Research Program and dean of the Graduate School of Biomedical Sciences. He also holds an adjunct position as professor in the Department of Pathology at the University of California, San Diego.
Education
1981: PhD, Cambridge University, England, Biology 1977: B. Sc., London University, London, England, Microbiology
Other Appointments
Adjunct Professor, Department of Pathology, University of California, San Diego
Honors and Recognition
2014: Organizer, Keystone Meeting on Cell Death, February 2013: IUBMB Gold Medal Recipient, October 2010: Keynote Speaker, European Cell Death Organization Conference, 2010: Keynote Speaker, Gordon Research Conference on Cell Death 2009: Lifetime Achievement Award of the International Proteolysis Society 2008: Keynote Speaker, Queenstown Molecular Biology Conference 2008: Chair, Gordon Research Conference on Cell Death 2005: Helmut Holzer Memorial Prize 1999: International Proteolysis Society, Elected Secretary 1999: Keynote Speaker, Gordon Research Conference on Matrix Metalloproteinases 1988: American Association for the Study of Liver Diseases, State of the Art Lecture 1996: Chair, Gordon Research Conference on Proteolytic Enzymes and Their Inhibitors
Related Disease
Cancer, Inflammatory/Autoimmune Disease, Neurodegenerative and Neuromuscular Diseases, Pancreatic Cancer, Skin Cancer and Melanoma, Structural Biology
Phenomena or Processes
Apoptosis and Cell Death, Caspase Family, Cytokines, Inflammation, Protein Structure-Function Relationships, Proteolytic Pathways, Ubiquitin, Ubiquitin Protease System and Ubiquitin-like Proteins
Research Models
Bacteria, Human Cell Lines, Mouse, Mouse Cell Lines, Primary Human Cells
Techniques and Technologies
Biochemistry, Cellular and Molecular Imaging, Chemical Biology, Fluorescence Microscopy, Mass Spectrometry, Protein Engineering, Protein Structure Prediction, Protein-Protein Interactions, Proteomics
The human body contains cells with different life expectancies. Some (white blood cells or skin, for example) are programmed to rapidly die and be replaced. Others (such as nerve cells) are programmed to survive the lifetime of the individual and are seldom replaced. Dr. Salvesen’s research focuses on the central role enzyme pathways play in the life and death of cells. When death pathways slow down in cells that are normally programmed to die, cancer results. Conversely, when death pathways become overactive in cells that are programmed to survive, degenerative disease occurs. Dr. Salvesen’s laboratory focuses on understanding the fundamental molecular interactions that occur within these enzyme pathways. This knowledge is used to engineer synthetic compounds to stimulate cell destruction in cancer cells, or delay cell destruction in neurodegenerative diseases and stroke.
Guy Salvesen’s Research Report
Structure and Function of Proteases and Their Natural Inhibitors
Our research seeks to delineate the structure –> activity –> function algorithm as it applies to proteases and their inhibitors. Our laboratory has very broad interests in principles of proteolysis in humans, and we take multi-pronged approaches to research on proteases and their inhibitors.
Apoptosis
In one approach we apply basic biochemical knowledge to investigate newly emerging principles of proteolysis in human systems. This research is currently dissecting the proteolytic components of the intracellular pathway that lead to apoptotic cell death. Programmed cell death monitors the growth of new cells and the elimination of old ones. This program contains a number of proteolytic steps that are essential for efficient execution of the death pathway. Thus the proteases of the pathway – the caspases – are involved in the normal maintenance of correct cell number, and are therefore implicated in a number of pathologic and physiologic conditions. Using the techniques of protein chemistry, enzymology, crystallography, and recombinant DNA methodologies, we analyze the basic mechanism utilized by caspases to promote cell death pathways, and the mechanisms and specificity of the natural inhibitors that control them.
Cell Signaling
Modification of proteins by the small ubiquitin-like modifier SUMO is a dynamic and reversible process. The SUMO cycle begins when SUMO precursors are processed to remove short C-terminal extensions, thereby uncapping the C-terminal Gly-Gly motif that is essential for conjugation. SUMO ligases conjugate the protein, via its C-terminal carboxylate, to the side-chain lysine of target proteins to generate an isopeptide linkage. Eventually, SUMO is removed intact from its substrate SUMOylated proteins, and so the SUMOylation/deSUMOylation cycle regulates SUMOs function. A group of proteases known as SENPs are involved in both the activation of SUMO precursors (endopeptidase cleavage) and deconjugation of the targets (isopeptidase cleavage). Our laboratory is currently involved in projects to define the mechanisms that regulate SENP activity and access to their natural substrates.
Technology Development
The principle of proteolysis in vivo is to instigate irreversible changes to a set of protein substrates that alters their function and generates the required biological event. The sum total of the proteases and their target substrates operating in a physiologic pathway therefore defines the global event. Consequently, the identity of the substrate cleavages defines the proteases acting on them. We are developing proteomics-based methodologies, including selective protein labeling, multi-dimensional electrophoresis, and mass spectrometry techniques, to identify the products of proteolysis in vivo.
Dr. Levine is Emeritus Professor at Sanford Burnham Prebys. Prior to that, he was a Professor in the Department of Pediatrics at the University of California, San Diego School of Medicine, where he continues to see children with inherited metabolic diseases. Dr. Levine received his undergraduate degree in biochemistry from Harvard and his MD and PhD degree in genetics from the University of Washington. His clinical training as a pediatric geneticist was at the Children’s Hospital of Philadelphia. Dr. Levine has been working in the field of cell transplantation therapies for diabetes and b-cell biology for more than fifteen years. His laboratory was the first to develop immortalized cell lines from the human endocrine pancreas as models of beta-cell growth and differentiation. He has made insights into cellular senescence in the endocrine pancreas, finding that b-cells undergo rapid senescence when stimulated to proliferate. Most recently, he and his co-workers demonstrated the existence of endocrine stem cells in the adult human pancreas. The laboratory continues to pursue the development of cell therapies for diabetes using a variety of approaches, including high throughput screening.
Education
1979-86: PhD, University of Washington (Genetics) 1979-86: MD, University of Washington 1975-79: A.B., Harvard University (Biochemistry)
Postgraduate Training
1989-91: Genetics Fellow, Dept. of Pediatrics, UCSD School of Medicine 1988-89: Clinical Genetics Fellow, Children’s Hosp. of Philadelphia 1987-89: Pediatric Resident, Children’s Hosp. of Philadelphia 1986-87: Pediatric Intern, Children’s Hosp. of Philadelphia
Other Appointments
Health Sciences Clinical Professor of Pediatrics, UCSD School of Medicine Attending Physician, Rady Children’s Hospital
Related Disease
Cancer, Childhood Diseases, Metabolic Diseases, Obesity, Type 1 Diabetes, Type 2 Diabetes
Diabetes is a disease in which there is an insufficient amount of insulin, produced by the pancreatic b-cells, to control the blood glucose concentration. In type I diabetes, the b-cell are destroyed by an autoimmune response, while in type II diabetes, the b-cells are dysfunctional and are ultimately lost because of obesity-associated pathology. Our laboratory is interested in how b-cells regenerate under normal and pathophysiological conditions, with the goal of developing new therapies for diabetes that result in an increased number of those cells. Our studies of b-cell growth have also led us to develop lead compounds that are active in cancer, an interesting connection as both obesity and diabetes are now recognized as major risk factors for cancer.
Fred Levine’s Research Report
The major interest in the laboratory is pancreatic beta-cell biology and specifically the control of beta-cell growth and differentiation in the adult pancreas. In both type I and type II diabetes, β-cell mass decreases and is a major factor in the pathogenesis of diabetes. Thus, one major question in which we are interested is the existence and nature of adult endocrine stem/progenitor cells. Using both human and rodent models, we study cells in vitro and in vivo to determine the competence of various cell populations to undergo endocrine differentiation in response to defined stimuli. The goal is to achieve a sufficient understanding of the process of adult β-cell regeneration to allow us to enhance β-cell mass in diabetes.
A second major area of emphasis is to use high-throughput screening to discover compounds that modulate important aspects of β-cell biology. Our focus has been on modulation of insulin promoter activity, as that gene is acted upon by many diabetogenic stimuli. We have isolated and are characterizing a number of compounds and genes that were discovered in the screening process. Recently, we have discovered ligands for the orphan nuclear receptor HNF4a. HNF4a is involved in a number of disease processes, including diabetes, liver disease, and cancer.
Kiselyuk A, Lee SH, Farber-Katz S, Zhang M, Athavankar S, Cohen T, Pinkerton AB, Ye M, Bushway P, Richardson AD, Hostetler HA, Rodriguez-Lee M, Huang L, Spangler B, Smith L, Higginbotham J, Cashman J, Freeze H, Itkin-Ansari P, Dawson MI, Schroeder F, Cang Y, Mercola M, Levine F
Minoru Fukuda earned his PhD in biochemistry from the University of Tokyo in 1973 and did his postdoctoral training at the Yale University School of Medicine. Following a period with joint appointments at University of Washington and Fred Hutchinson Cancer Research Center in Seattle, he was recruited to Sanford-Burnham Medical Research Institute in 1982 as Director of the Glycobiology Program. Dr. Fukuda directs the program project grant, which consolidates the research efforts of the members of the Glycobiology Program.
Dr. Fukuda is a recipient of a Merit Award from the National Cancer Institute and the 1997 recipient of the Karl Meyer Award from the Society of Glycobiology. He served as an Executive Editor for Biochimica et Biophysica Acta, as an Associate Editor for Cancer Research and Editorial Member for Journal of Biological Chemistry. He also has edited 11 books including three books from Oxford University Press and three volumes of Methods in Enzymology and holds an Adjunct Professor appointment at the University of California, San Diego.
Education
1973: PhD, University of Tokyo, Biochemistry 1970: MS, University of Tokyo, Biochemistry 1968: BS, University of Tokyo, Biochemistry
Related Disease
Brain Cancer, Colorectal Cancer, Gastric Cancer, Helicobacter pylori, Prostate Cancer
The cell surface is heavily coated with carbohydrates. The structure of those cell surface carbohydrates displays a dramatic change during development, and mature cells express cell surface carbohydrates specific to different organs and tissues. Cell surface carbohydrates thus serve as a zip code for different organs and tissues. Sialyl Lewis X represents such an oligosaccharide. After discovery of sialyl Lewis X in neutrophils by Dr. Minoru Fukuda, his laboratory demonstrated that sulfated form of sialyl Lewis X is essential for lymphocyte homing and recruitment of natural killer cells in preventing tumor metastasis to the peripheral lymph node. With colleagues from Japan, Dr. Fukuda discovered that certain carbohydrates function as antibiotics against Helicobacter pylori infection, which is a leading cause for peptic ulcer and gastric carcinoma. Most recent studies in Dr. Fukuda’s laboratory revealed that decrease of the laminin-binding glycans on α-dystroglycan in carcinoma cells leads to tumor cell migration, invasion, and metastasis. The restoration of the unique glycans by the expression of distinct β3-N-acetylglucosaminyltransferase renders these cells act like normal cells. The results indicate that certain carbohydrates on normal cells and enzymes that synthesize those glycans, such as β3-N-acetylglucosaminyltransferase, function as tumor suppressors These findings will be useful in developing carbohydrate-based therapy for the treatment of inflammation and tumor metastasis.
Minoru Fukuda’s Research Report
Cell Surface Carbohydrates as Tumor Suppressor
Many studies have focused on carbohydrates that increase in cancer cells, but only a few have looked at carbohydrates that appear in normal cells but decrease or disappear in cancer cells. A specific mucin-type O-glycans (core 3 O-glycans) is one of such glycans, and we found core 3 O-glycans suppress tumor formation and metastasis. When core 3 O-glycans were forced to express on human prostate cancer cell lines, those prostate cancer cells produced much smaller tumors and almost no metastasis. By contrast, the parent cancer cells, which did not express core 3 O-glycans, produced robust primary and metastatic tumors. We showed that the expression of core 3 O-glycans decreases a formation of α2β1-integrin complex, receptors that mediate cell adhesion, diminishing cancer cell migration.
We also revealed tumor suppressor function in the unique laminin-binding glycans on dystrophin complex, — carbohydrates located on α-dystroglycan, which is also associated with cell adhesion. We discovered that the unique glycans play a critical role in epithelial-basement membrane interaction in normal cells, and the decrease or loss of the glycans, due to downregulation of β3-N-acetylglucosaminyltransferase, leads to increased malignancy by invasive carcinoma cells. Restoration of the laminin-binding glycans by forced expression of β3-N-acetylglucosaminyltransferase, on the other hand, results in reduced cell migration, thus dramatic decrease in tumor formation and metastasis. We demonstrated that interaction of laminin with the unique glycans on α-dystroglycan counteracts the cell migration signals that are mediated by integrin binding to its ligands, thereby decreasing tumor formation and metastasis. These findings also suggest that the laminin-binding glycans can be an excellent marker for epithelial-mesenchymal transitions.
These results indicate that certain carbohydrates on normal cells and enzymes that synthesize those glycans, such as β3-N-acetylglucosaminyltransferase, function as tumor suppressors. Upregulation of those key enzymes may become a novel way to treat cancer.
Neural Cell-specific Glycans in Development and Cancer
Polysialic acid and HNK-1 glycan represent carbohydrates enriched in neural cells. Polysialic acid is mainly attached to NCAM in embryos, while the majority of NCAM in adults lack this carbohydrate. To understand the roles of these glycans in neural development, we have cloned cDNAs encoding human polysialyltransferase, PST, and HNK-1 sulfotransferase, HNK-1ST, that are responsible for the synthesis of polysialic acid and HNK-1 glycan, respectively. By using these cloned cDNAs, we demonstrated that polysialic acid facilitates the invasion of glioma, the most common form of adult brain tumor. Our studies also showed that mutant mice with deficient STX, another polysialyltransferase, exhibit reduced behavioral response to fear conditioning, apparently due to anomalies in mossy fibers of the hippocampus. Our studies also demonstrated that neural development is significantly impaired in mutant mice that entirely lack polysialic acid due to inactivation of two polysialyltransferases. We found that this defect is caused by impairment of neural cell migration.
Mucin-type O-glycans in Immune Cell Interactions
Previously, we found that an increase of core 2-branched oligosaccharides is associated with leukemia and immunodeficiency, such as in Wiskott-Aldrich syndrome and AIDS. To determine the roles of core 2-branched O-glycans in immune cell interactions, the enzyme (C2GnT-1) responsible for the core 2-branched oligosaccharide was knocked-out by gene targeting. Compared to wild-type mice, leukocytes from the gene knockout mice exhibited a reduced binding to L-, E- and P-selectin in this order. In contrast, homing of lymphocytes was moderately reduced. Lymphocyte homing is mediated by binding of L-selectin on lymphocytes to sulfated L-selectin oligosaccharide ligands, 6-sulfo sialyl Lewis X in high endothelial venules (HEV) of secondary lymphoid organs. By analyzing remaining L-selectin ligands in C2GnT-1 knockout mice, we discovered novel L-selectin ligands that are based on extended core 1 oligosaccharides. The core portion of this novel L-selectin ligand is also an epitope for MECA-79 antibody that inhibits lymphocyte homing in vivo. Moreover, crossbreeding between mutant mice with deficient L-selectin ligand sulfotransferase and another sulfotransferase led to our findings that these two enzymes in cooperation synthesize L-selectin ligands. These mutant mice lack 6-sulfate group in L-selectin ligands that results in impaired inflammatory response. More recently, mice deficient in L-selectin ligands on mucin-type O-glycans were generated. The studies on the mutant mice revealed novel functions of N-glycan-based L-selectin ligand, which supports both lymphocyte homing and inflammatory response. This finding brought a new paradigm in selectin-carbohydrate interaction.
Carbohydrate-dependent Adhesion in Tumor Metastasis
Previously we found that the amount of core 2 O-glycans is significantly increased in colon and lung carcinomas and the increase of core 2 O-glycans is highly correlated to vessel invasion and lymph node metastasis. More recently, we discovered that forced expression of core 2 O-glycans by transfecting C2GnT-1 in prostate cancer cell lines resulted in increased tumor formation.
In parallel, we discovered that forced expression of selectin ligands, sialyl Lewis X on B16 melanoma cells leads to increased lung tumor formation. We also showed that tumor formation in lymph node is suppressed by natural killer (NK) cells, which are recruited by L-selectin mediated homing of NK cells to lymph nodes.
Roles of Carbohydrates in Helicobacter pylori-mediated Inflammation and Cancer
Helicobacter pylori is a leading cause of peptic ulcer and gastric cancer. Previously it was shown by others that H. pylori adhere to gastric mucosa in a carbohydrate-dependent manner. The infection of H. pylori leads to chronic inflammation, which apparently leads to peptic ulcer and gastric cancer.
Our recent studies showed that H. pylori-induced inflammation is associated with the formation of peripheral lymph node addressin (PNAd) characterized by binding to MECA-79 antibody and L-selectin. The number of HEV-like vessels expressing PNAd increases as H. pylori-induced inflammation progresses. Moreover, PNAd disappears once H. pyloriis eradicated by antibiotic treatment. These findings indicate that H. pylori-induced inflammation is facilitated by de novo formation of PNAd thereby recruiting lymphocytes. It may be possible to attenuate or prevent the formation of peptic ulcers or gastric cancer by inhibiting L-selectin ligand synthesis, for example by inhibiting the sulfotransferases.
Binding of laminin to the specific carbohydrate (shown in bright green) on α-dystroglycan counteracts the migration signals initiated by integrin binding to extracellular matrix proteins such as laminin and fibronectin. The synthesis of this specific carbohydrate requires a unique β3-N-cetylglucosaminyltransferase, and the downregulation of the glycosyltransferase in carcinoma cells leads to increased cell migration, thereby increased tumor formation and metastasis. Thus the specific carbohydrate structure at cell surface functions as a tumor suppressor, which is controlled by the unique β3-N-acetylglucosaminyltransferase.
While over half of the world’s population is infected with H. pylori, only a fraction of those individuals progress to peptic ulcer and gastric cancer. In relation to these observations, α1,4-N-acteylglucosaminyl capping structure (α4GlcNAc) is present in deeper portions of the gastric mucosa, where H. pylori rarely colonizes. We discovered that α4GlcNAc capping structure functions as an antibiotic against H. pylori infection by inhibition of the synthesis of α-glucosyl cholesterol, a major component of the H. pyloricell wall. This unprecedented discovery should be useful in developing drugs to inhibit H. pylori colonization, through inhibition of cholesterol α-glucosyltransferase. Such drugs lead to a novel treatment for prevention and potential treatment of peptic ulcer and gastric carcinoma.
Michiko N. Fukuda earned her PhD in biochemistry at the University of Tokyo in 1980. She did postdoctoral work at Fred Hutchinson Cancer Research Center in Seattle prior to her recruitment to Sanford-Burnham Medical Research Institute in 1982.
Education
1980: PhD, University of Tokyo, Biochemistry 1970: MS, University of Tokyo, Biochemistry 1968: BS, Tokyo University of Education, Botany
Related Disease
Breast Cancer, Cancer, Congenital Disorders of Glycosylation, Endometriosis, Glycosylation-Related Disorders, Inherited Disorders, Ovarian Cancer, Prostate Cancer, Testicular Cancer
Michiko Fukuda’s Research Report
Identification of Peptide that Delivers Drugs to Tumors
Chemotherapy effectiveness is often limited by drug toxicity in healthy tissues, although methods that spare normal cells by delivering drugs specifically to tumors may help to overcome this constraint. We have identified a promising tumor-targeted drug delivery vehicle known as the IF7 peptide. Using in vitro assays, we found that the IF7 peptide bound to the protein annexin 1 (Anxa1), which is known from previous studies by others to be enriched on the surface of tumor vasculature in several tumor types. When we injected a fluorescently labeled IF7 peptide into mice with tumors, fluorescent signals appeared in the tumors within one minute of injection. By contrast the tumors showed no fluorescence when mice were pre-injected with anti-Anxa1 antibodies that inhibits IF7-Anxa1 binding, suggesting that the peptide targets tumor by homing to Anxa1.
Effect of IF7-conjugated anti-cancer drug SN-38 on colon cancer mouse model. Activa cancer cells in a large tumor produce chemiluminescence which is captured by imaging. (Hatakeyama et al, 2011).
When IF7 peptide was conjugated with potent anti-cancer drug SN-38 and IF7-SN38 conjugate was injected intravenously to mice with tumors, IF7 could deliver SN-38 to tumors. We found that daily injections of an IF7-SN38 conjugate reduced a large tumor in the mouse without apparent side effects, whereas non-homing peptide-SN38 conjugate or with SN-38 alone did not reduce the tumors (Hatakeyama et al, 2011). The findings suggest that IF7 peptide may represent a clinically relevant vehicle for anti-cancer drugs.
Role of Trophinin in Human Embryo Implantation and Cancer
Invasion of the trophoblast into the endometrium, an essential element of embryo implantation, resembles invasion of malignant tumors. At the initial phase of implantation, the trophoblast and the uterine epithelium establish their first contact via their respective apical cell membranes. We have identified new molecules, trophinin, tastin, and bystin that mediate cell adhesion between trophoblastic cells and endometrial epithelial cells at the respective apical cell membranes. Trophinin is an intrinsic membrane protein, and tastin and bystin are cytoplasmic proteins. All of these molecules are strongly expressed in cells involved in embryo implantation in humans. However, trophinin is not expressed in human endometrial epithelia throughout the hormonal cycle, except only those cells located close to the implanting blastocyst. Trophinin expression by endometrial epithelia is induced by human chorionic gonadotrophin (hCG) derived from the implanting embryo (Sugihara et al, 2008). While embryos invade maternal cells (Sugihara et al, 2007), maternal tissue accepts embryos. We asked what happens in the maternal epithelia when trophinin-mediated adhesion takes place, and found that trophinin-mediated cell adhesion triggers an apoptotic signal in maternal epithelial cells (Tamura et al, 2011).
Distinct signal transduction of trophinin-mediated cell adhesion in trophectoderm cell and endometrial epithelial cells. In trophoblastic cells, ErbB4 (receptor tyrosine kinase) is arrested by bystin/trophinin complex. When trophinin-mediated cell adhesion takes palce, ErbB4 is released from bystin. This allows ErbB4 to be activated by phosphorylation. In endometrial epithelial cells, trophinin-mediated cell adhesion releases PKCd from trophinin. PKCd was then translocated to the nucleus, where it activates caspase 3 for apoptosis (Tamura et al., 2011).
References Cited
Hatakeyama S, Sugihara K, Shibata TK, Nakayama J, Akama TO, Tamura N, Wong SM, Bobkov AA, Takano Y, Ohyama C, Fukuda M, Fukuda MN (2011) Targeted drug delivery to tumor vasculature by a carbohydrate mimetic peptide. Proc Natl Acad Sci U S A 108: 19587-19592
Sugihara K, Kabir-Salmani M, Byrne J, Wolf DP, Lessey B, Iwashita M, Aoki D, Nakayama J, Fukuda MN (2008) Induction of trophinin in human endometrial surface epithelia by CGbeta and IL-1beta. FEBS Lett 582: 197-202
Sugihara K, Sugiyama D, Byrne J, Wolf DP, Lowitz KP, Kobayashi Y, Kabir-Salmani M, Nadano D, Aoki D, Nozawa S, Nakayama J, Mustelin T, Ruoslahti E, Yamaguchi N, Fukuda MN (2007) Trophoblast cell activation by trophinin ligation is implicated in human embryo implantation. Proc Natl Acad Sci U S A 104: 3799-3804
Tamura N, Sugihara K, Akama TO, Fukuda MN (2011) Trophinin-mediated cell adhesion induces apoptosis of human endometrial epithelial cells through PKC-delta. Cell Cycle 10 : 135-143
