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Found 37684 matches. Displaying 1251-1260
Lalazar G, Requena D, Ramos-Espiritu L, Ng D, Bhola PD, de Jong YP, Wang RS, Narayan NJC, Shebl B, Levin S, Michailidis E, Kabbani M, Vercauteren KOA, Hurley AM, Farber BA, Hammond WJ, Saltsman JA, Weinberg EM, Glickman JF, Lyons BA, Ellison J, Schadde E, Hertl M, Leiting JL, Truty MJ, Smoot RL, Tierney F, Kato T, Wendel HG, LaQuaglia MP, Rice CM, Letai A, Coffino P, Torbenson MS, Ortiz MV, Simon SM
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Identification of Novel Therapeutic Targets for Fibrolamellar Carcinoma Using Patient-Derived Xenografts and Direct-from-Patient Screening

CANCER DISCOVERY 2021 OCT; 11(10):2544-2563
To repurpose therapeutics for fibrolamellar carcinoma (FLC), we developed and validated patient-derived xenografts (PDX) from surgical resections. Most agents used clinically and inhibitors of oncogenes overexpressed in FLC showed little efficacy on PDX. A high-throughput functional drug screen found primary and metastatic FLC were vulnerable to clinically available inhibitors of TOPO1 and HDAC and to napabucasin. Napabucasin's efficacy was mediated through reactive oxygen species and inhibition of translation initiation, and specific inhibition of eIF4A was effective. The sensitivity of each PDX line inversely correlated with expression of the antiapoptotic protein Bcl-xL, and inhibition of Bcl-xL synergized with other drugs. Screening directly on cells dissociated from patient resections validated these results. This demonstrates that a direct functional screen on patient tumors provides therapeutically informative data within a clinically useful time frame. Identifying these novel therapeutic targets and combination therapies is an urgent need, as effective therapeutics for FLC are currently unavailable. SIGNIFICANCE: Therapeutics informed by genomics have not yielded effective therapies for FLC. A functional screen identified TOPO1, HDAC inhibitors, and napabucasin as efficacious and synergistic with inhibition of Bcl-xL. Validation on cells dissociated directly from patient tumors demonstrates the ability for functional precision medicine in a solid tumor.
Al-Massadi O, Dieguez C, Schneeberger M, Lopez M, Schwaninger M, Prevot V, Nogueiras R
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Multifaceted actions of melanin-concentrating hormone on mammalian energy homeostasis

NATURE REVIEWS ENDOCRINOLOGY
Melanin-concentrating hormone (MCH) integrates physiological functions and mood states associated with energy and glucose homeostasis. In this Review, Al-Massadi et al. describe how MCH regulates the hedonic component of food intake and discuss its potential as a therapeutic target. Melanin-concentrating hormone (MCH) is a small cyclic peptide expressed in all mammals, mainly in the hypothalamus. MCH acts as a robust integrator of several physiological functions and has crucial roles in the regulation of sleep-wake rhythms, feeding behaviour and metabolism. MCH signalling has a very broad endocrine context and is involved in physiological functions and emotional states associated with metabolism, such as reproduction, anxiety, depression, sleep and circadian rhythms. MCH mediates its functions through two receptors (MCHR1 and MCHR2), of which only MCHR1 is common to all mammals. Owing to the wide variety of MCH downstream signalling pathways, MCHR1 agonists and antagonists have great potential as tools for the directed management of energy balance disorders and associated metabolic complications, and translational strategies using these compounds hold promise for the development of novel treatments for obesity. This Review provides an overview of the numerous roles of MCH in energy and glucose homeostasis, as well as in regulation of the mesolimbic dopaminergic circuits that encode the hedonic component of food intake.
Henry KE, Mack KN, Nagle VL, Cornejo M, Michel AO, Fox IL, Davydova M, Dilling TR, Pillarsetty N, Lewis JS
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ERK Inhibition Improves Anti-PD-L1 Immune Checkpoint Blockade in Preclinical Pancreatic Ductal Adenocarcinoma

MOLECULAR CANCER THERAPEUTICS 2021 OCT 1; 20(10):2026-2034
Patients with pancreatic ductal adenocarcinoma (PDAC) do not benefit from immune checkpoint blockade (ICB) along the PD-1/PD-L1 axis. Variable PD-L1 expression in PDAC indicates a potential access issue of PD-L1-targeted therapy. To monitor target engagement of PD-L1-targeted therapy, we generated a PD-L1targeted PET tracer labeled with zirconium-89 (Zr-89). As theMAPK signaling pathway (MEK and ERK) is known to modulate PD-L1 expression in other tumor types, we used [Zr-89] Zr-DFO-anti-PDL1 as a tool to noninvasively assess whether manipulation of the MAPK signaling cascade could be leveraged to modulate PD-L1 expression and thereby immunotherapeutic outcomes in PDAC. In this study, we observed that the inhibition of MEK or ERK is sufficient to increase PD-L1 expression, which we hypothesized could be leveraged for anti-PD-L1 immune checkpoint therapy. We found that the combination of ERK inhibition and anti-PDL1 therapy corresponded with a significant improvement of overall survival in a syngeneic mouse model of PDAC. Furthermore, IHC analysis indicates that the survival benefit may be CD8(+) T-cell mediated. The therapeutic and molecular imaging tool kit developed could be exploited to better structure clinical trials and address the therapeutic gaps in challenging malignancies such as PDAC.
Boisson-Dupuis S, Bustamante J
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Mycobacterial diseases in patients with inborn errors of immunity

CURRENT OPINION IN IMMUNOLOGY 2021 OCT; 72(?):262-271
Clinical disease caused by the agent of tuberculosis, Mycobacterium tuberculosis, and by less virulent mycobacteria, such as bacillus Calmette-Guerin (BCG) vaccines and environmental mycobacteria, can result from inborn errors of immunity (IEIs). IEIs underlie more than 450 conditions, each associated with an impairment of the development and/or function of hematopoietic and/or non-hematopoietic cells involved in host defense. Only a minority of IEIs confer predisposition to mycobacterial disease. The IEIs underlying susceptibility to bona fide tuberculosis are less well delineated than those responsible for susceptibility to less virulent mycobacteria. However, all these IEIs share a defining feature: the impairment of immunity mediated by interferon gamma (IFN-gamma). More profound IFN-gamma deficiency is associated with a greater vulnerability to weakly virulent mycobacteria, whereas more selective IFN-gamma deficiency is associated with a more selective predisposition to mycobacterial disease. We review here recent progress in the study of IEIs underlying mycobacterial diseases.
Perry JK, Appleby TC, Bilello JP, Feng JY, Schmitz U, Campbell EA
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An atomistic model of the coronavirus replication-transcription complex as a hexamer assembled around nsp15

JOURNAL OF BIOLOGICAL CHEMISTRY 2021 OCT; 297(4):? Article 101218
The SARS-CoV-2 replication-transcription complex is an assembly of nonstructural viral proteins that collectively act to reproduce the viral genome and generate mRNA transcripts. While the structures of the individual proteins involved are known, how they assemble into a functioning superstructure is not. Applying molecular modeling tools, including protein- protein docking, to the available structures of nsp7-nsp16 and the nucleocapsid, we have constructed an atomistic model of how these proteins associate. Our principal finding is that the complex is hexameric, centered on nsp15. The nsp15 hexamer is capped on two faces by trimers of nsp14/nsp16/ (nsp10)2, which then recruit six nsp12/nsp7/(nsp8)2 polymerase subunits to the complex. To this, six subunits of nsp13 are arranged around the superstructure, but not evenly distributed. Polymerase subunits that coordinate dimers of nsp13 are capable of binding the nucleocapsid, which positions the 50UTR TRS-L RNA over the polymerase active site, a state distinguishing transcription from replication. Analysis of the viral RNA path through the complex indicates the dsRNA that exits the polymerase passes over the nsp14 exonuclease and nsp15 endonuclease sites before being unwound by a convergence of zinc fingers from nsp10 and nsp14. The template strand is then directed away from the complex, while the nascent strand is directed to the sites responsible for mRNA capping. The model presents a cohesive picture of the multiple functions of the coronavirus replication-transcription complex and addresses fundamental questions related to proofreading, template switching, mRNA capping, and the role of the endonuclease.
Lee RH, Kang H, Yom SS, Smogorzewska A, Johnson DE, Grandis JR
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Treatment of Fanconi Anemia-Associated Head and Neck Cancer: Opportunities to Improve Outcomes

CLINICAL CANCER RESEARCH 2021 OCT 1; 27(19):5168-5187
Fanconi anemia, the most frequent genetic cause of bone marrow failure, is characterized by an extreme predilection toward multiple malignancies, including a greater than 500-fold incidence of head and neck squamous cell carcinoma (HNSCC) relative to the general population. Fanconi anemia-associated HNSCC and esophageal SCC (FA-HNSCC) often present at advanced stages with poor survival. Surgical resection remains the primary treatment for FA-HNSCC, and there is often great reluctance to administer systemic agents and/or radiotherapy to these patients given their susceptibility to DNA damage. The paucity of FA-HNSCC case reports limits evidence-based management, and such cases have not been analyzed collectively in detail. We present a systematic review of FA-HNSCC treatments reported from 1966 to 2020, defining a cohort of 119 patients with FA-HNSCC including 16 esophageal SCCs (131 total primary tumors), who were treated with surgery, radiotherapy, systemic therapy (including cytotoxic agents, EGFR inhibitors, or immune checkpoint inhibitors), or a combination of modalities. We summarize the clinical responses and regimen-associated toxicities by treatment modality. The collective evidence suggests that when possible, surgical resection with curative intent should remain the primary treatment modality for FA-HNSCC. Radiation can be administered with acceptable toxicity in the majority of cases, including patients who have undergone stem cell transplantation. Although there is little justification for cytotoxic chemotherapy, EGFR inhibitors and tyrosine kinase inhibitors may be both safe and effective. Immunotherapy may also be considered. Most oncologists have little personal experience with FA-HNSCC. This review is intended as a comprehensive resource for clinicians.
Michel AO, Donovan TA, Roediger B, Lee Q, Jolly CJ, Monette S
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Chaphamaparvovirus antigen and nucleic acids are not detected in kidney tissues from cats with chronic renal disease or immunocompromised cats

VETERINARY PATHOLOGY
Chronic kidney disease (CKD) is a common cause of morbidity and mortality in domestic cats, but the cause is still largely elusive. While some viruses have been associated with this disease, none have been definitively implicated as causative. Recently, Rodent chaphamaparvovirus 1 was recognized as the cause of murine inclusion body nephropathy, a disease reported for over 40 years in laboratory mice. A novel virus belonging to the same genus, Carnivore chaphamaparvovirus 2, was recently identified in the feces of cats with diarrhea. The goal of this study was to investigate the possible role of chaphamaparvoviruses including members of Rodent chaphamaparvovirus 1 and Carnivore chaphamaparvovirus 2 in the development of feline CKD. The presence of these viruses was retrospectively investigated in formalin-fixed paraffin-embedded feline kidney samples using polymerase chain reaction, in situ hybridization, and immunohistochemistry. Cats were divided into 3 groups: normal (N = 24), CKD (N = 26), and immunocompromised (N = 25). None of the kidney tissues from any of the 75 cats revealed the presence of chaphamaparvovirus DNA, RNA, or antigen. We conclude that viruses belonging to the chaphamaparvovirus genus are unlikely to contribute to the occurrence of feline CKD.
Philippot Q, Casanova JL, Puel A
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Candidiasis in patients with APS-1: low IL-17, high IFN-gamma, or both?

CURRENT OPINION IN IMMUNOLOGY 2021 OCT; 72(?):318-323
Chronic mucocutaneous candidiasis (CMC) is one of the earliest and most frequent clinical manifestations of autosomal recessive autoimmune polyendocrine syndrome type 1 (APS1), a monogenic inborn error of immunity caused by deleterious variants of the autoimmune regulator (AIRE) gene. APS-1 patients suffer from various autoimmune diseases, due to the defective thymic deletion of autoreactive T cells, and the development of a large range of autoantibodies (auto-Abs) against various tissue antigens, and some cytokines. The mechanisms underlying CMC remained elusive for many years, until the description in 2010 of high serum titers of neutralizing auto-Abs against IL-17A, IL-17F, and/or IL-22, which are present in almost all APS-1 patients. Excessively high mucosal concentrations of IFN-gamma were recently proposed as an alternative mechanism for CMC in APS-1.
Baez-Mendoza R, Vazquez Y, Mastrobattista EP, Williams ZM
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Neuronal Circuits for Social Decision-Making and Their Clinical Implications

FRONTIERS IN NEUROSCIENCE 2021 OCT 1; 15(?):? Article 720294
Social living facilitates individual access to rewards, cognitive resources, and objects that would not be otherwise accessible. There are, however, some drawbacks to social living, particularly when competing for scarce resources. Furthermore, variability in our ability to make social decisions can be associated with neuropsychiatric disorders. The neuronal mechanisms underlying social decision-making are beginning to be understood. The momentum to study this phenomenon has been partially carried over by the study of economic decision-making. Yet, because of the similarities between these different types of decision-making, it is unclear what is a social decision. Here, we propose a definition of social decision-making as choices taken in a context where one or more conspecifics are involved in the decision or the consequences of it. Social decisions can be conceptualized as complex economic decisions since they are based on the subjective preferences between different goods. During social decisions, individuals choose based on their internal value estimate of the different alternatives. These are complex decisions given that conspecifics beliefs or actions could modify the subject's internal valuations at every choice. Here, we first review recent developments in our collective understanding of the neuronal mechanisms and circuits of social decision-making in primates. We then review literature characterizing populations with neuropsychiatric disorders showing deficits in social decision-making and the underlying neuronal circuitries associated with these deficits.

Buitrago L, Lefkowitz S, Bentur O, Padovan J, Allen BC
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Platelet binding to polymerizing fibrin is avidity driven and requires activated aIIbb3 but not fibrin cross-linking

BLOOD ADVANCES 2021 OCT 26; 5(20):3986-4002
The molecular basis of platelet-fibrin interactions remains poorly understood despite the predominance of fibrin in thrombi. We have studied the interaction of platelets with polymerizing fibrin by adding thrombin to washed platelets in the presence of the peptide RGDW, which inhibits the initial platelet aggregation mediated by fibrinogen binding to aIIbb3 but leaves intact a delayed increase in light transmission (delayed wave; DW) as platelets interact with the polymerizing fibrin. The DW was absent in platelets from a patient with Glanzmann thrombasthenia, indicating a requirement for aIIbb3. The DW required aIIbb3 activation and it was inhibited by the aIIbb3 antagonists eptifibatide and the monoclonal antibody (mAb) 7E3, but only at much higher concentrations than needed to inhibit platelet aggregation initiated by a thrombin receptor activating peptide (T6). Surface plasmon resonance and scanning electron microscopy studies both supported fibrin having greater avidity for aIIb b3 than fibrinogen rather than greater affinity, consistent with fibrin's multivalency. mAb 10E5, a potent inhibitor of T6-induced platelet aggregation, did not inhibit the DW, suggesting that fibrin differs from fibrinogen in its mechanism of binding. Inhibition of factor XIII-mediated fibrin cross-linking by .95% reduced the DW by only 32%. Clot retraction showed a pattern of inhibition similar to that of the DW. We conclude that activated aIIbb3 is the primary mediator of platelet-fibrin interactions leading to clot retraction, and that the interaction is avidity driven, does not require fibrin cross-linking, and is mediated by a mechanism that differs subtly from that of the interaction of aIIbb3 with fibrinogen.