Zikherman J.,University of California at San Francisco |
Jenne C.,University of California at San Francisco |
Watson S.,University of California at San Francisco |
Doan K.,University of California at San Francisco |
And 6 more authors.
Immunity | Year: 2010
The kinase-phosphatase pair Csk and CD45 reciprocally regulate phosphorylation of the inhibitory tyrosine of the Src family kinases Lck and Fyn. T cell receptor (TCR) signaling and thymic development require CD45 expression but proceed constitutively in the absence of Csk. Here, we show that relative titration of CD45 and Csk expression reveals distinct regulation of basal and inducible TCR signaling during thymic development. Low CD45 expression is sufficient to rescue inducible TCR signaling and positive selection, whereas high expression is required to reconstitute basal TCR signaling and beta selection. CD45 has a dual positive and negative regulatory role during inducible but not basal TCR signaling. By contrast, Csk titration regulates basal but not inducible signaling. High physiologic expression of CD45 is thus required for two reasons-to downmodulate inducible TCR signaling during positive selection and to counteract Csk during basal TCR signaling. © 2010 Elsevier Inc.
News Article | December 7, 2016
A new study published in the just-published "Oncotarget" peer-reviewed medical journal has concluded that “in the setting of previously treated, advanced pancreatic cancer, liquid biopsies are not yet an adequate substitute for tissue biopsies. Further refinement in defining the optimal patient population and timing of blood sampling may improve the value of a blood-based test.” The study was conducted by a team of researchers and clinicians from Perthera, Inc., a precision medicine company based in McLean, VA, the Pancreatic Cancer Action Network (PanCAN), Lombardi Comprehensive Cancer Center of Georgetown University, Cedars-Sinai Medical Center, Ohio State University, City of Hope Cancer Center, Virginia Mason Medical Center, and the Sidney Kimmel Cancer Center at Thomas Jefferson University. The study is entitled "a pilot study evaluating concordance between blood-based and patient-matched tumor molecular testing within pancreatic patients participating in the Know Your Tumor (KYT) Initiative." Know Your Tumor is a benchmark precision cancer therapy program of the Pancreatic Cancer Action Network that is executed by Perthera. The study asserted that “molecular profiling of the tumor itself should remain the gold standard,” or as approved by the FDA. Liquid biopsies can "go wrong" in a variety of ways: mainly because the tumor isn't dumping DNA into the blood, or because the detection assays aren't sensitive enough to detect the DNA when it is too low in abundance to see. The investigators assessed the ability of the circulating genomic information obtained from a blood sample of 34 consecutively screened pancreatic cancer patients with metastatic disease to accurately recapitulate the genomic information obtained by direct analysis of a tumor biopsy obtained from the same patient taken at the same time. They used the high frequency of KRAS mutation (~90%) in pancreatic cancer as a benchmark for comparison, and they found that KRAS mutations “were only detected in 10/34 (29%) blood samples, compared to 20/23 (87%) tumor tissue biopsies." Dr. Jonathan Brody, the last author on the study and Director of Surgical Research and Co-director of the Jefferson Pancreas, Biliary and Related Cancer Center and on the scientific advisory board at Perthera, cautioned that "the results of this study should give people some pause; we need to be very careful about the state of the liquid biopsy field right now." He said, "we need to be very circumspect- in this study, we detected DNA with KRAS mutations in only a third of the patients that you should see the genomic alteration, so what does it say about being able to reliably detect actionable alterations that doctors would use to make critical treatment decisions?” Dr. Michael Pishvaian, the first author of the study and Perthera’s CMO as well as the Director of the Phase I Clinical Program and Co-Director of the Ruesch Center Pancreatic Cancer Program at Georgetown University added that “there will be times when a tumor biopsy is unable to be performed due to medical issues, and then could a liquid biopsy be considered. Pishvaian says: “There are papers that show good but not perfect concordance between the genomic information in tumor samples and blood samples, and our study in pancreatic cancer reveals something different. Some of the disparate results from these studies come from differences in the clinical aspects of the patients studied, but ultimately if liquid biopsies are to be used routinely for precision medicine applications then the field needs more improvements.” In the meantime, Emanuel “Chip” Petricoin, PhD, Perthera’s Chief Science Officer said, “Central to Perthera’s medical philosophy is that the patient should have as extensive molecular profiling as relevant, and blood-based testing will be great to add to our arsenal of testing options as it becomes more reliable and sensitive. So, we are committed to implementing molecular profiling technologies that have the best evidence of impact to patients' precision cancer therapy outcome and we will be constantly monitoring the state of the field on this topic. As the liquid biopsy technologies and approaches improve and become more sensitive, then we can validate them and implement them." ABOUT PERTHERA, INC.: Perthera is a founder- and venture-backed precision medicine company based in McLean, VA, that has achieved more than 1,000 case histories since it was founded about five years ago, often working in an alliance with cancer advocacy agencies as well as hospitals, community oncology practices, and academia. In every patient instance, the Company seeks to become the precision medicine partner on their cancer care team, providing the widest, deepest, and most independent range of service possible.
News Article | November 30, 2016
PHILADELPHIA -- Progranulin is produced and secreted by most cells in the body. From skin to immune cells, brain to bone marrow cells, progranulin plays a key role in maintaining normal cellular function. In cancer, too much progranulin makes tumors (particularly prostate carcinomas) more aggressive and metastatic, whereas in neurodegenerative diseases, too little is associated with disease onset and progression. Until now, studying progranulin has been tricky as the receptor that communicates biological information to the cell's signaling machinery has remained elusive for decades. Now, researchers at Thomas Jefferson University's Sidney Kimmel Cancer Center discovered a cell-surface receptor highly expressed by cancerous and brain cells that directly and tightly binds progranulin. Importantly, the researchers also showed that this binding activates a cellular program that makes cancer cells more aggressive. The results were published in The Journal of Cell Biology. "Identifying the functional signaling receptor for progranulin will help us understand how this molecule functions in cancer and whether pharmacologically targeting it will slow the progression of a number of cancers," says Renato V. Iozzo, M.D., Ph.D., Gonzalo E. Aponte Professor and Deputy Chair of the Department of Pathology, Anatomy & Cell Biology at Thomas Jefferson University and researcher at the Sidney Kimmel Cancer Center at Jefferson. "It may also help researchers better understand the role of progranulin function and deficiency in neurodegenerative diseases including Parkinson's, Alzheimer's, and possibly even autism." Using an array of unbiased biochemical and cellular approaches, the researchers demonstrated that Ephrin type-A receptor 2, or EphA2, bound tightly to progranulin. Following progranulin binding, key components of the intracellular signaling apparatus that are involved in both cancer-promoting and perhaps neurodegenerative processes known as Akt and Erk1/2, were rapidly activated. When EphA2 was blocked, however, these pathways did not activate. The researchers further showed that progranulin binding triggered a positive feed-forward loop, wholly dependent on EphA2 signaling that increased the secretion of progranulin from the cancer cell. Finally, when EphA2 was depleted from endothelial cells, progranulin failed to trigger the formation of new blood vessels, a process considered essential for progressive tumor growth and metastasis. Researchers had previously identified other receptors with progranulin-binding abilities: sortilin and tumor necrosis factor receptor 1 and 2 (TNFR1/2). Sortilin is capable of binding progranulin outside the cell and internalizing it, while TNFR1/2 are receptors primarily involved in coordinating inflammatory responses. Recent reports had cast doubt as to whether these two candidate receptors were bona fide progranulin receptors. In one instance, changes in neuronal outgrowth were seen even when sortilin was absent and some evidence questioned whether TNFR1/2 could bind directly to progranulin at all. Indeed, when Dr. Iozzo and colleagues removed sortilin from the cells expressing EphA2, they found that sortilin was not necessary for progranulin/EphA2 signaling. They found that cells lacking sortilin accumulate progranulin outside of the cell, and can therefore increase the bioavailability of progranulin to signal via EphA2 to augment more progranulin production. In pathological situations where progranulin levels are vital, understanding the mechanism of the progranulin/EphA2 feedback loop may prove key to disease development and progression. "The discovery of EphA2 as a receptor for progranulin is somewhat unexpected, in part because it was commonly believed that Ephrin receptors only bound other members of the vast Ephrin family," said Dr. Iozzo. "This finding turns that expectation on its head, and offers new tools and concepts for exploring pathological, and homeostatic functions of progranulin." This work was supported in part by National Institutes of Health grants RO1 CA39481, RO1 CA47282, RO1 CA164462, and NIH training grant T32 AR060715-04. The authors report no conflicts of interest. Article reference: T Neill, et al., "EphA2 is a functional receptor for the growth factor progranulin." J Cell Biol. 2016. Jefferson, through its academic and clinical entities of Thomas Jefferson University and Jefferson Health, including Abington Health and Aria Health, is reimagining health care for the greater Philadelphia region and southern New Jersey. Jefferson has 23,000 people dedicated to providing the highest-quality, compassionate clinical care for patients, educating the health professionals of tomorrow, and discovering new treatments and therapies to define the future of care. With a university and hospital that date to 1824, today Jefferson is comprised of six colleges, nine hospitals, 34 outpatient and urgent care locations, and a multitude of physician practices throughout the region, serving more than 100,000 inpatients, 373,000 emergency patients and 2.2 million outpatient visits annually. For more information and a complete listing of Jefferson services and locations, visit http://www. .
News Article | October 27, 2016
(PHILADELPHIA) -- The immune system orchestrates large and small scale attacks on innumerous targets: viruses, bacteria, cancer, but it also misfires causing allergy or autoimmune reactions. Compounding the problem, not every immune reaction is equal - sometimes a necessary reaction is not strong enough or at times it's too strong. Now Thomas Jefferson University researchers have developed a new way to determine the strength of an immune response to a particular antigen. The results, published in Nature Communications on October 27th, could be used to help doctors personalize immune-modulating therapies - like cancer immunotherapies, or immunosuppressive therapies used in organ transplantation - more effectively. "The test, which we've named the CaFlux, is rapid, sensitive, and can test a broad array of antigenic targets," says senior author Yuri Sykulev, M.D., Ph.D., a Professor of Microbiology and Immunology and of Medical Oncology at the Sidney Kimmel Cancer Center at Jefferson "A future application of this test could help determine who might respond with a sneeze versus who might respond with anaphylactic shock before it happened." While other tests for the strength of the immune response exist, some take one to two days and others are not as sensitive as the CaFlux. The speed (a few minutes) of Dr. Sykulev's method relies on the ability to detect one of the first changes an immune cell undergoes after recognizing a target: the opening of calcium channels. The test works by attaching immune cells that can both respond to as well as display potential immune targets, and then flowing potential antigens over top to look for "matches." If the addition of antigen leads to a match between displayer and responder, the two cells grab hold of each other with their receptors. That grasp triggers calcium channels to open, which then activates a green fluorescence in the cells. The green light can be easily detected by microscope and quantified by image-reading software. The stronger the match, the more calcium floods into the cell, and the brighter the green color. The weaker the match, the less calcium enters the cells over a longer period of time, producing a dimmer glow without a strong spike. The test can help researchers see both how many T-cells respond in a given sample, as well as how powerfully and how rapidly each individual cell responds over time. These three pieces of information could more accurately predict how a person would react to a wide array of immune threats, from viral or bacterial attacks to allergens. The test could be useful in developing better vaccines, assessing the potency of immunotherapy interventions, and understanding the severity of disease -- and therefore the appropriate level of medical intervention. To try out the principal on a real application, Dr. Sykulev and colleagues tested T-cells from a bone marrow transplant recipient for reactivity to cytomegalovirus (CMV). Most people harbor CMV, but the infection is usually kept in check by a healthy immune system. The virus can be deadly when it becomes reactivated in some bone marrow recipients whose immune system has been wiped out before the transplant. Today, doctors have limited ways of predicting whose CMV will become reactivated. When the researchers tested the new T cells after the transplant, the cells showed a slow and weak response to the same antigens, or CMV targets. "That weak response was mirrored by what happened in the clinic," says oncologist Neal Flomenberg, Professor and Chair of the Department of Medical Oncology and Deputy Director of the Sidney Kimmel Cancer Center at Jefferson, who was also involved in the study. "The patient's CMV reactivated while the immune system was still rebooting and unable to mount a strong response against CMV, and he had to be treated for the infection. Had we been able to monitor this patient's immune system's ability to respond to CMV, we may have been able to tailor his treatment to better keep the CMV in check." The researchers hope to develop this assay for use in applications ranging from cancer to basic immunology. The assay is protected by pending patent (US62/183,997) and was supported by Pharma Germinator program of Southwestern PA and 5P30CA056036-17 core grant to the Sidney Kimmel Cancer Center. The authors declare no additional conflicts of interest. For more information, contact Edyta Zielinska, 215-955-5291, firstname.lastname@example.org, or Gail Benner, 215-955-2240, email@example.com. Article Reference: N. Anikeeva, et al., "Evaluating frequency and quality of pathogen-specific T cells," Nature Communications, DOI: 10.1038/ncomms13264, 2016. Jefferson, through its academic and clinical entities of Thomas Jefferson University and Jefferson Health, is reimagining health care for the greater Philadelphia region and southern New Jersey. Since its mergers with Abington Health and Aria Health, Jefferson now has 23,000 people dedicated to providing the highest-quality, compassionate clinical care for patients, educating the health professionals of tomorrow, and discovering new treatments and therapies to define the future of care. With a university and hospital that date to 1824, today Jefferson is comprised of six colleges, nine hospitals, 32 outpatient and urgent care locations, and a multitude of physician practices throughout the region, serving more than 96,000 inpatients, 363,000 emergency patients and 1.9 million outpatient visits annually. For more information and a complete listing of Jefferson services and locations, visit http://www. .
Chaudhary N.,Johns Hopkins University |
Datta K.,Johns Hopkins University |
Askin F.B.,Johns Hopkins University |
Staab J.F.,Johns Hopkins University |
And 2 more authors.
American Journal of Respiratory and Critical Care Medicine | Year: 2012
Rationale: Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) alter epithelial cell (EC) interactions with multiple microbes, such that dysregulated inflammation and injury occur with airway colonization in people with cystic fibrosis (CF). Aspergillus fumigatus frequently colonizes CF airways, but it has been assumed tobe an innocent saprophyte; its potential role as a cause of lung disease is controversial. Objectives: To study the interactions between Aspergillus and EC, and the role of the fungus in evoking inflammatory responses. Methods: A. fumigatus expressing green fluorescent protein was developed for in vitro and in vivo models, which used cell lines and mouse tracheal EC. Measurements and Main Results: Fungal spores (conidia) are rapidly ingested by ECs derived from bronchial cell lines and murine tracheas, supporting a role for EC in early airway clearance. Bronchial ECs harboring CFTR mutations (ΔF508) or deletion demonstrate impaired uptake and killing of conidia, and ECs with CFTR mutation undergo more conidial-induced apoptosis. Germinated (hyphal) forms of the fungus evoke secretion ofinflammatory mediators, with CFTR mutation resulting in increased airway levels of macrophage inflammatory protein 2 and KC, and higher lung monocyte chemotactic protein-1. After A. fumigatus inhalation, CFTR -/- mice develop exaggerated lymphocytic inflammation, mucin accumulation, and lung injury. Conclusions: Data demonstrate a critical role for CFTR in mediating EC responses to A. fumigatus. Results suggest that the fungus elicits aberrant pulmonary inflammation in the setting of CFTR mutation, supporting the potential role of antifungals to halt progressive CF lung disease. Copyright © 2012 by the American Thoracic Society.
Oh P.,Proteogenomics Research Institute for Systems Medicine |
Oh P.,Sidney Kimmel Cancer Center |
Testa J.E.,Proteogenomics Research Institute for Systems Medicine |
Testa J.E.,Sidney Kimmel Cancer Center |
And 8 more authors.
Nature Medicine | Year: 2014
Technologies are needed to map and image biological barriers in vivo that limit solid tumor delivery and, ultimately, the effectiveness of imaging and therapeutic agents. Here we integrate proteomic and imaging analyses of caveolae at the blood-tumor interface to discover an active transendothelial portal to infiltrate tumors. A post-translationally modified form of annexin A1 (AnnA1) is selectively concentrated in human and rodent tumor caveolae. To follow trafficking, we generated a specific AnnA1 antibody that targets caveolae in the tumor endothelium. Intravital microscopy of caveolae-immunotargeted fluorophores even at low intravenous doses showed rapid and robust pumping across the endothelium to enter mammary, prostate and lung tumors. Within 1 h, the fluorescence signal concentrated throughout tumors to exceed the peak levels in blood. This transvascular pumping required the expression of caveolin 1 and annexin A1. Tumor uptake with other antibodies were >100-fold less. This proteomic imaging strategy reveals a unique target, antibody and caveolae pumping system for solid tumor penetration. © 2014 Nature America, Inc. All rights reserved.
Le D.T.,Sidney Kimmel Cancer Center |
Dubenksy Jr. T.W.,Aduro Biotech |
Brockstedt D.G.,Aduro Biotech
Seminars in Oncology | Year: 2012
Active immunotherapy targeting dendritic cells (DCs) has shown great promise in preclinical models and in human clinical trials for the treatment of malignant disease. Sipuleucel-T (Provenge, Dendreon, Seattle, WA), which consists of antigen-loaded dendritic cells (DCs), recently became the first targeted therapeutic cancer vaccine to be approved by the US Food and Drug Administration (FDA). However, ex vivo therapies such as Provenge have practical limitations and elicit an immune response with limited scope. By contrast, live-attenuated Listeria monocytogenes (Lm) naturally targets DCs in vivo and stimulates both innate and adaptive cellular immunity. Lm-based vaccines engineered to express cancer antigens have demonstrated striking efficacy in several animal models and have resulted in encouraging anecdotal survival benefit in early human clinical trials. Two different Lm-based vaccine platforms have advanced into phase II clinical trials in cervical and pancreatic cancer. Future Lm-based clinical vaccine candidates are expected to feature polyvalent antigen expression and to be used in combination with other immunotherapies or conventional therapies such as radiotherapy and chemotherapy to augment efficacy. © 2012 Elsevier Inc. © 2012 Elsevier Inc. All rights reserved.
Hassan R.,U.S. National Institutes of Health |
Cohen S.J.,Chase Medical |
Phillips M.,Morphotek Inc. |
Pastan I.,U.S. National Institutes of Health |
And 5 more authors.
Clinical Cancer Research | Year: 2010
Purpose: MORAb-009 is a chimeric monoclonal antibody that targets mesothelin, a tumor differentiation antigen overexpressed in pancreatic cancer, ovarian cancer, mesothelioma, and other malignancies. We conducted a phase I clinical trial of MORAb-009 in patients with advanced mesothelin-expressing cancers to determine its safety, dose-limiting toxicity (DLT), and maximum tolerated dose (MTD). Methods: Cohorts consisting of 3 to 6 subjects each received MORAb-009 intravenously on days 1, 8, 15, and 22 at progressively increasing doses ranging from 12.5 to 400 mg/m2. Disease evaluation with computed tomography occurred on day 35. Subjects with responding or stable disease could receive additional cycles of MORAb-009. Results: A total of 24 subjects were treated including 13 mesothelioma, 7 pancreatic cancer, and 4 ovarian cancer patients. The median number of MORAb-009 infusions was 4 (range 1-24 infusions). At the 400 mg/m2 dose level, 2 subjects experienced DLT (grade 4 transaminitis and a grade 3 serum sickness). Thus, although there were other contributing causes of these adverse events, 200 mg/m2 was considered the MTD. Other adverse events at least possibly related to MORAb-009 included 7 drug hypersensitivity events (all grade 1 or 2) and a thromboembolic event (grade 4). Eleven subjects had stable disease. There was a dose-dependent increase in serum MORAb-009 concentration. Conclusion: MORAb-009 is well tolerated and the MTD when administered weekly is conservatively set at 200 mg/m2. In this group of previously treated patients, 11 subjects had stable disease. Phase II studies of MORAb-009 in different mesothelin-expressing cancers are ongoing. ©2010 AACR.
Kim J.A.,Sidney Kimmel Cancer Center |
Lee J.,Sidney Kimmel Cancer Center |
Margolis R.L.,Sidney Kimmel Cancer Center |
Margolis R.L.,Sanford Burnham Institute for Medical Research |
And 2 more authors.
Oncogene | Year: 2010
Cell cycle controls ensure that DNA replication (S phase) follows mitosis resulting in two precise copies of the genome. A failure of the control mechanisms can result in multiple rounds of DNA replication without cell division. In endoreplication, cells with replicated genomes bypass mitosis, then replicate their DNA again, resulting in polyploidy. Endoreplication from G2 phase lacks all hallmarks of mitosis. Using synchronized cells, we show that the c-Jun N-terminal kinase (JNK) inhibitor, SP600125, prevents the entry of cells into mitosis and leads to endoreplication of DNA from G2 phase. We show that cells proceed from G2 phase to replicate their DNA in the absence of mitosis. This effect of SP600125 is independent of its suppression of JNK activity. Instead, the inhibitory effect of SP600125 on mitotic entry predominantly occurs upstream of Aurora A kinase and Polo-like kinase 1, resulting in a failure to remove the inhibitory phosphorylation of Cdk1. Importantly, our results directly show that the inhibition of Cdk1 activity and the persistence of Cdk2 activity in G2 cells induces endoreplication without mitosis. Furthermore, endoreplication from G2 phase is independent of p53 control. © 2010 Macmillan Publishers Limited All rights reserved.
Li R.,Viral Oncology Program |
Hayward S.D.,Viral Oncology Program |
Hayward S.D.,Sidney Kimmel Cancer Center
Trends in Microbiology | Year: 2013
Herpesviruses are ubiquitous human pathogens that establish lifelong persistent infections. Clinical manifestations range from mild self-limiting outbreaks such as childhood rashes and cold sores to the more severe and life-threatening outcomes of disseminated infection, encephalitis, and cancer. Nucleoside analog drugs that target viral DNA replication provide the primary means of treatment. However, extended use of these drugs can result in selection for drug-resistant strains, particularly in immunocompromised patients. In this review we will present recent observations about the participation of cellular protein kinases in herpesvirus biology and discuss the potential for targeting these protein kinases as well as the herpesvirus-encoded protein kinases as an anti-herpesvirus therapeutic strategy. © 2013 Elsevier Ltd.