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1.
Vet Dermatol ; 2024 Aug 14.
Article in English | MEDLINE | ID: mdl-39140285

ABSTRACT

BACKGROUND: Mycobacterium cell wall fraction (MCWF) is derived from nonpathogenic Mycobacterium phlei and is used as an immunomodulatory compound in clinical practice, yet its mode-of-action requires further research. OBJECTIVE: To evaluate the host response to MCWF in canine peripheral blood mononuclear cells (PBMCs) by using enzyme-linked immunosorbent assays (ELISA) and quantitative reverse transcription (qRT)-PCR for assessment of cytokines. ANIMALS: Eight healthy Labrador retrievers. MATERIALS AND METHODS: PBMCs were isolated from whole blood using density centrifugation. The cells were cultured with different concentrations of MCWF or a potent stimulator of cytokine production, phorbol 12-myristate 13-acetate/ionomycin, or left in cell culture medium for 24, 48 and 72 h. Cytokines were measured by ELISA for interleukin (IL)-4, IL-10 and interferon-gamma (IFN-γ), and by qRT-PCR for IL-4, IL-10, IL-13, IFN-γ, tumour necrosis factor alpha (TNF-α) and transforming growth factor-beta. RESULTS: A significant increase of IL-10 messenger ribonucleic acid (mRNA) was detected at all time points for all concentrations of MCWF (p < 0.05). Protein analysis reflected this finding, with a maximum IL-10 concentration of 300.6 ± 38.3 µg/mL. Compared to the negative control, post-stimulation elevation of IFN-γ mRNA was noted at 24 h with all concentrations of MCWF (p < 0.01), and TNF-α mRNA was increased for 0.5 µg/dL MCWF only at 72 h (p < 0.05). CONCLUSIONS AND CLINICAL RELEVANCE: MCWF stimulation of PBMCs results in the elevation of both proinflammatory and regulatory cytokine mRNA. Further research into the role of MCWF as a systemically administered regulatory immunomodulator or adjuvant to allergen-specific immunotherapy should be considered.

2.
Genet Med ; 26(11): 101231, 2024 Aug 09.
Article in English | MEDLINE | ID: mdl-39132680

ABSTRACT

PURPOSE: Pediatric cholestasis is the phenotypic expression of clinically and genetically heterogeneous disorders of bile acid synthesis and flow. Although a growing number of monogenic causes of pediatric cholestasis have been identified, the majority of cases remain undiagnosed molecularly. METHODS: In a cohort of 299 pediatric participants (279 families) with intrahepatic cholestasis, we performed exome sequencing as a first-tier diagnostic test. RESULTS: A likely causal variant was identified in 135 families (48.56%). These comprise 135 families that harbor variants spanning 37 genes with established or tentative links to cholestasis. In addition, we propose a novel candidate gene (PSKH1) (HGNC:9529) in 4 families. PSKH1 was particularly compelling because of strong linkage in 3 consanguineous families who shared a novel hepatorenal ciliopathy phenotype. Two of the 4 families shared a founder homozygous variant, whereas the third and fourth had different homozygous variants in PSKH1. PSKH1 encodes a putative protein serine kinase of unknown function. Patient fibroblasts displayed abnormal cilia that are long and show abnormal transport. A homozygous Pskh1 mutant mouse faithfully recapitulated the human phenotype and displayed abnormally long cilia. The phenotype could be rationalized by the loss of catalytic activity observed for each recombinant PSKH1 variant using in vitro kinase assays. CONCLUSION: Our results support the use of genomics in the workup of pediatric cholestasis and reveal PSKH1-related hepatorenal ciliopathy as a novel candidate monogenic form.

3.
J Phys Chem B ; 128(28): 6693-6703, 2024 Jul 18.
Article in English | MEDLINE | ID: mdl-38976601

ABSTRACT

We present a comprehensive study investigating the potential gain in accuracy for calculating absolute solvation free energies (ASFE) using a neural network potential to describe the intramolecular energy of the solute. We calculated the ASFE for most compounds from the FreeSolv database using the Open Force Field (OpenFF) and compared them to earlier results obtained with the CHARMM General Force Field (CGenFF). By applying a nonequilibrium (NEQ) switching approach between the molecular mechanics (MM) description (either OpenFF or CGenFF) and the neural net potential (NNP)/MM level of theory (using ANI-2x as the NNP potential), we attempted to improve the accuracy of the calculated ASFEs. The predictive performance of the results did not change when this approach was applied to all 589 small molecules in the FreeSolv database that ANI-2x can describe. When selecting a subset of 156 molecules, focusing on compounds where the force fields performed poorly, we saw a slight improvement in the root-mean-square error (RMSE) and mean absolute error (MAE). The majority of our calculations utilized unidirectional NEQ protocols based on Jarzynski's equation. Additionally, we conducted bidirectional NEQ switching for a subset of 156 solutes. Notably, only a small fraction (10 out of 156) exhibited statistically significant discrepancies between unidirectional and bidirectional NEQ switching free energy estimates.

4.
Am J Pathol ; 2024 Jul 18.
Article in English | MEDLINE | ID: mdl-39032600

ABSTRACT

Muscle atrophy and weakness are prevalent features of cancer. Although extensive research has characterized skeletal muscle wasting in cancer cachexia, limited studies have investigated how cardiac structure and function are affected by therapy-naive cancer. Here, the authors used orthotopic, syngeneic models of epithelial ovarian cancer and pancreatic ductal adenocarcinoma, and a patient-derived pancreatic xenograft model, to define the impacts of malignancy on cardiac structure, function, and metabolism. Tumor-bearing mice develop cardiac atrophy and intrinsic systolic and diastolic dysfunction, with arterial hypotension and exercise intolerance. In hearts of ovarian tumor-bearing mice, fatty acid-supported mitochondrial respiration decreased, and carbohydrate-supported respiration increased-showcasing a substrate shift in cardiac metabolism that is characteristic of heart failure. Epithelial ovarian cancer decreased cytoskeletal and cardioprotective gene expression, which was paralleled by down-regulation of transcription factors that regulate cardiomyocyte size and function. Patient-derived pancreatic xenograft tumor-bearing mice show altered myosin heavy chain isoform expression-also a molecular phenotype of heart failure. Markers of autophagy and ubiquitin-proteasome system were upregulated by cancer, providing evidence of catabolic signaling that promotes cardiac wasting. Together, the authors cross-validate with two cancer types, evidence of the structural, functional, and metabolic cancer-induced cardiomyopathy, thus providing translational evidence that could impact future medical management strategies for improved cancer recovery in patients.

5.
Mol Pharm ; 21(8): 3800-3814, 2024 Aug 05.
Article in English | MEDLINE | ID: mdl-39051563

ABSTRACT

Two anhydrous polymorphs of the novel antiviral medicine nirmatrelvir were discovered during the development of Paxlovid, Pfizer's oral Covid-19 treatment. A comprehensive experimental and computational approach was necessary to distinguish the two closely related polymorphs, herein identified as Forms 1 and 4. This approach paired experimental methods, including powder X-ray diffraction and single-crystal X-ray diffraction, solid-state experimental methods, thermal analysis, solid-state nuclear magnetic resonance and Raman spectroscopy with computational investigations comprising crystal structure prediction, Gibbs free energy calculations, and molecular dynamics simulations of the polymorphic transition. Forms 1 and 4 were ultimately determined to be enantiotropically related polymorphs with Form 1 being the stable form above the transition temperature of ∼17 °C and designated as the nominated form for drug development. The work described in this paper shows the importance of using highly specialized orthogonal approaches to elucidate the subtle differences in structure and properties of similar solid-state forms. This synergistic approach allowed for unprecedented speed in bringing Paxlovid to patients in record time amidst the pandemic.


Subject(s)
Antiviral Agents , COVID-19 Drug Treatment , Crystallization , Molecular Dynamics Simulation , X-Ray Diffraction , Antiviral Agents/chemistry , X-Ray Diffraction/methods , Crystallography, X-Ray/methods , Magnetic Resonance Spectroscopy/methods , Spectrum Analysis, Raman/methods , SARS-CoV-2/drug effects , Transition Temperature
6.
J Chem Inf Model ; 64(10): 4286-4297, 2024 May 27.
Article in English | MEDLINE | ID: mdl-38708520

ABSTRACT

C-H borylation is a high-value transformation in the synthesis of lead candidates for the pharmaceutical industry because a wide array of downstream coupling reactions is available. However, predicting its regioselectivity, especially in drug-like molecules that may contain multiple heterocycles, is not a trivial task. Using a data set of borylation reactions from Reaxys, we explored how a language model originally trained on USPTO_500_MT, a broad-scope set of patent data, can be used to predict the C-H borylation reaction product in different modes: product generation and site reactivity classification. Our fine-tuned T5Chem multitask language model can generate the correct product in 79% of cases. It can also classify the reactive aromatic C-H bonds with 95% accuracy and 88% positive predictive value, exceeding purpose-developed graph-based neural networks.


Subject(s)
Hydrogen , Hydrogen/chemistry , Models, Chemical , Neural Networks, Computer
7.
Mol Metab ; 81: 101887, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38280449

ABSTRACT

OBJECTIVE: Lipotoxic injury from renal lipid accumulation in obesity and type 2 diabetes (T2D) is implicated in associated kidney damage. However, models examining effects of renal ectopic lipid accumulation independent of obesity or T2D are lacking. We generated renal tubule-specific adipose triglyceride lipase knockout (RT-SAKO) mice to determine if this targeted triacylglycerol (TAG) over-storage affects glycemic control and kidney health. METHODS: Male and female RT-SAKO mice and their control littermates were tested for changes in glycemic control at 10-12 and 16-18 weeks of age. Markers of kidney health and blood lipid and hormone concentrations were analyzed. Kidney and blood lysophosphatidic acid (LPA) levels were measured, and a role for LPA in mediating impaired glycemic control was evaluated using the LPA receptor 1/3 inhibitor Ki-16425. RESULTS: All groups remained insulin sensitive, but 16- to 18-week-old male RT-SAKO mice became glucose intolerant, without developing kidney inflammation or fibrosis. Rather, these mice displayed lower circulating insulin and glucagon-like peptide 1 (GLP-1) levels. Impaired first-phase glucose-stimulated insulin secretion was detected and restored by Exendin-4. Kidney and blood LPA levels were elevated in older male but not female RT-SAKO mice, associated with increased kidney diacylglycerol kinase epsilon. Inhibition of LPA-mediated signaling restored serum GLP-1 levels, first-phase insulin secretion, and glucose tolerance. CONCLUSIONS: TAG over-storage alone is insufficient to cause renal tubule lipotoxicity. This work is the first to show that endogenously derived LPA modulates GLP-1 levels in vivo, demonstrating a new mechanism of kidney-gut-pancreas crosstalk to regulate insulin secretion and glucose homeostasis.


Subject(s)
Diabetes Mellitus, Type 2 , Glucagon-Like Peptide 1 , Animals , Female , Male , Mice , Diabetes Mellitus, Type 2/metabolism , Glucagon-Like Peptide 1/metabolism , Glucose/metabolism , Inflammation/metabolism , Insulin/metabolism , Insulin Secretion , Kidney/metabolism , Lipid Metabolism , Lipids , Obesity/metabolism
8.
Vet Comp Oncol ; 22(1): 96-105, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38237918

ABSTRACT

The standard treatment for canine lymphoma is the CHOP chemotherapy regimen. Proteasome inhibitors have been employed with CHOP for the treatment of human haematological malignancies but remain to be fully explored in canine lymphoma. We identified an association between poor response to CHOP chemotherapy and high mRNA expression levels of proteasomal subunits in a cohort of 15 canine lymphoma patients, and sought to determine the effect of proteasome inhibitors on the viability of a canine B-cell lymphoma cell line (CLBL-1). The aim of this study was to investigate whether proteasome inhibitors sensitize these cells to the CHOP agents doxorubicin, vincristine and cyclophosphamide (as 4-hydroxycyclophosphamide/4-HC). CLBL-1 cells were sensitive to proteasome inhibition by bortezomib and ixazomib. The IC50 of bortezomib was 15.1 nM and of ixazomib was 59.14 nM. Proteasome inhibitors plus doxorubicin had a synergistic effect on CLBL-1 viability; proteosome inhibitors plus vincristine showed different effects depending on the combination ratio, and there was an antagonistic effect with 4-HC. These results may have clinical utility, as proteasome inhibition could potentially be used with a synergizing CHOP compound to improve responsiveness to chemotherapy for canine lymphoma patients.


Subject(s)
Boron Compounds , Dog Diseases , Glycine/analogs & derivatives , Lymphoma , Humans , Animals , Dogs , Proteasome Inhibitors/pharmacology , Proteasome Inhibitors/therapeutic use , Bortezomib/pharmacology , Bortezomib/therapeutic use , Vincristine/pharmacology , Vincristine/therapeutic use , Proteasome Endopeptidase Complex , Dog Diseases/drug therapy , Cyclophosphamide/pharmacology , Cyclophosphamide/therapeutic use , Prednisone/pharmacology , Prednisone/therapeutic use , Doxorubicin/pharmacology , Doxorubicin/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/pharmacology , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Lymphoma/drug therapy , Lymphoma/veterinary
9.
J Chem Theory Comput ; 20(2): 799-818, 2024 Jan 23.
Article in English | MEDLINE | ID: mdl-38157475

ABSTRACT

Biomolecular simulations have become an essential tool in contemporary drug discovery, and molecular mechanics force fields (FFs) constitute its cornerstone. Developing a high quality and broad coverage general FF is a significant undertaking that requires substantial expert knowledge and computing resources, which is beyond the scope of general practitioners. Existing FFs originate from only a limited number of groups and organizations, and they either suffer from limited numbers of training sets, lower than desired quality because of oversimplified representations, or are costly for the molecular modeling community to access. To address these issues, in this work, we developed an AMBER-consistent small molecule FF with extensive chemical space coverage, and we provide Open Access parameters for the entire modeling community. To validate our FF, we carried out benchmarks of quantum mechanics (QM)/molecular mechanics conformer comparison and free energy perturbation calculations on several benchmark data sets. Our FF achieves a higher level of performance at reproducing QM energies and geometries than two popular open-source FFs, OpenFF2 and GAFF2. In relative binding free energy calculations for 31 protein-ligand data sets, comprising 1079 pairs of ligands, the new FF achieves an overall root-mean-square error of 1.19 kcal/mol for ΔΔG and 0.92 kcal/mol for ΔG on a subset of 463 ligands without bespoke fitting to the data sets. The results are on par with those of the leading commercial series of OPLS FFs.


Subject(s)
Benchmarking , Molecular Dynamics Simulation , Thermodynamics , Entropy , Proteins/chemistry , Ligands
10.
Mol Ther Oncolytics ; 31: 100748, 2023 Dec 19.
Article in English | MEDLINE | ID: mdl-38075247

ABSTRACT

Immunotherapies revive host immune responses against tumors by stimulating innate and adaptive immune effector cells with antitumor functions. Thus, detailed studies of immunological cell phenotypes and functions within the tumor microenvironment (TME) following immunotherapy treatments is critical to identifying the determinants of therapeutic success, optimizing treatment regimens, and driving curative outcomes. Oncolytic viruses such as Orf virus (OrfV) are multifunctional biologics that preferentially infect and kill cancer cells while simultaneously causing inflammation that drives anticancer immune responses. Here, we describe the immunological impact of OrfV on the ascites TME in a preclinical model of advanced-stage epithelial ovarian cancer. OrfV promoted the infiltration of several immune effector cells with increased expression of activation markers and effector cytokines into the ascites TME, which correlated with reduced ascites tumor burden and improved survival. The kinetics of the immune response and change in tumor burden following OrfV therapy revealed an optimal re-administration time to sustain antitumor immunity, further extending survival. The data presented highlight the importance of investigating immune response kinetics following immunotherapy and demonstrate that detailed kinetic profiling of immune responses can reveal novel insights into mechanisms of action that can guide the development of more effective therapies.

11.
Vet Comp Oncol ; 21(3): 541-550, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37337253

ABSTRACT

Enumeration of circulating tumour cells (CTC) has shown promise for prognostication and guidance of therapeutic decisions in human cancers. The objective of this study was to enumerate CTC over time in dogs with naturally occurring osteosarcoma (OSA), and to determine correlation with patient outcome. Twenty-six dogs with OSA and no evidence of metastatic disease at the time of amputation were enrolled. Dogs were assessed for lung metastases and CTC prior to and following amputation, and at each chemotherapy visit. Twenty-one dogs completed the study. Nineteen dogs were euthanized and two were alive and free of metastases. Overall survival time ranged from 88 to 1058 days (median survival time (MST) 374 days). Increased serum alkaline phosphatase activity, advanced age, and higher body weight were significantly associated with lower MST. Dogs with OSA had a mean of 356 (0 to 4443) CTC/106 leukocytes. In 12 of 15 dogs that developed radiographic evidence of metastasis, a pre-metastatic CTC spike was retrospectively detectable on average 36.5 (1-100 days) days prior to metastasis and was associated with significantly shorter MST (301 ± 64 vs. 626 ± 55 days; p = .0107). In a multivariable analysis, dogs with a CTC spike were 10× more likely to die compared with those without. These results suggest that a spike in CTC frequency precedes detection of metastasis in dogs with OSA and is associated with shorter survival. More frequent enumeration of CTC in a larger cohort of dogs with OSA may be warranted.


Subject(s)
Bone Neoplasms , Dog Diseases , Neoplastic Cells, Circulating , Osteosarcoma , Dogs , Humans , Animals , Retrospective Studies , Bone Neoplasms/veterinary , Bone Neoplasms/drug therapy , Dog Diseases/pathology , Osteosarcoma/drug therapy , Osteosarcoma/veterinary
12.
Environ Plan A ; 55(3): 673-696, 2023 May.
Article in English | MEDLINE | ID: mdl-37192929

ABSTRACT

The COVID-19 pandemic has resulted in governments playing increasingly prominent roles as active economic agents. However, state capitalism does not necessarily serve broad developmental purposes, and rather can be directed to supporting sectional and private interests. As the literature on variegated capitalism alerts us, governments and other actors regularly devise fixes in response to a systemic crisis, but the focus, scale, and scope of the interventions vary considerably, according to the constellation of interests. Rapid progress with vaccines notwithstanding, the UK government's response to COVID-19 has been associated with much controversy, not only because of an extraordinarily high death rate, but also because of allegations of cronyism around the granting of government contracts and bailouts. We focus on the latter, investigating more closely who got bailed out. We find that badly affected sectors (e.g. hospitality, transportation) and larger employers were more likely to get bailouts. However, the latter also favored the politically influential and those who had run up debt profligately. Although, as with state capitalism, crony capitalism is most often associated with emerging markets, we conclude that the two have coalesced into a peculiarly British variety, but one that has some common features with other major liberal markets. This might suggest that the eco-systemic dominance of the latter is coming to an end, or, at the least, that this model is drifting towards one that assumes many of the features commonly associated with developing nations.

13.
PLoS One ; 18(3): e0283616, 2023.
Article in English | MEDLINE | ID: mdl-36996057

ABSTRACT

Canine Mast cell tumors (MCTs) constitute approximately 21% of all canine skin tumors. Despite the use of comprehensive grading systems, biological aggressiveness is sometimes difficult to predict, therefore there is a need for better prognostic markers. Progression in various cancers involves DNA hypermethylation, hypomethylation and epigenetic enzyme dysregulation. Therefore, global levels of 5-methylcytosine, 5-hydroxymethylcytosine and associated enzymes DNMT1, and IDH1 expression may predict MCT aggressiveness. A tissue microarray (TMA) with cores from 244 different tumor samples from 189 dogs was immunolabelled and used to quantify the global DNA methylation and hydroxymethylation levels as well as the levels of the enzymes involved in DNA methylation and their relationship with canine MCT outcome. From the immunolabelled TMA, H-scores were generated using QuPath (v0.1.2) and analyzed with associated patient data. High 5MC and DNMT1, and low IDH1 levels were associated with poorer outcome when looking at all canine MCT cases. High 5MC levels showed significance for shorter disease-free interval (DFI) in subcutaneous cases and high 5MC levels showed poorer DFI and overall survival (OS) in cases with Kiupel's grading system high grade. Cases with grade II in Patnaik's grading system showed better DFI with low levels of DNMT1 and better OS with low levels of 5MC and 5HMC. High levels of DNMT1 staining were also associated with shorter DFI for dermal MCTs. For cases that received adjuvant therapy in addition to surgery, all parameters except IDH1 were significantly associated with OS. Therefore, there is potential for DNA methylation status and levels of enzymes associated with DNA methylation pathways to better predict outcome in canine MCT, and to possibly influence treatment decisions.


Subject(s)
Dog Diseases , Skin Neoplasms , Dogs , Animals , Prognosis , Mast Cells/metabolism , Dog Diseases/pathology , Skin Neoplasms/pathology , Epigenesis, Genetic
14.
PLoS One ; 18(3): e0283244, 2023.
Article in English | MEDLINE | ID: mdl-36928240

ABSTRACT

Hypertrophic cardiomyopathy (HCM) is the most common heart disease in cats, characterized by primary left ventricular hypertrophy. Feline HCM closely resembles human HCM and is suggested as translational animal model for the human disease. A genetic cause is established in humans and suspected for cats, but little is known about the gene expression and pathways involved in the pathogenesis of HCM. To investigate the myocardial transcriptome changes in HCM, RNA sequencing was conducted on left ventricle (LV) and left atrium (LA) samples of healthy cats and cats with HCM (each n = 5; 20 samples). Ingenuity Pathway Analysis was used to determine functional pathways, regulators, and networks. Distinct gene expression profiles were identified in the LV and LA of the feline healthy and HCM myocardium. Analysis of differentially expressed mRNAs (>2 fold; FDR < 0.01) found chamber-specific (LV vs. LA) expression in both healthy and HCM groups, with higher transcriptional activity in the LA. Genes that contribute to the distinct structure and function of each chamber in health and HCM were identified in the regional comparison. The gene expression profiles of HCM compared to healthy hearts revealed disease related genes, including THBS4 and KLHL33 (LV), FAM177B and THRSP (LA), the latter 3 have not been reported for the myocardium so far, as the top differently expressed genes in the HCM heart. Differently expressed genes and functional pathways found in the HCM heart are associated with cardiac remodeling and fibrosis, inflammation, microvascular changes, calcium signaling and cardiac metabolism, with some regional differences. RhoGDI-RhoGTPase signaling, integrin and ILK signaling pathways, the LXR/RXR pathway in the LA, and the PPARα/RXRα, HIF1α and CXCR4 pathways in the LV might be of particular importance in the HCM disease process. This study identified region-specific myocardial gene transcription patterns as well as novel genes and pathways associated with HCM.


Subject(s)
Cardiomyopathy, Hypertrophic , Transcriptome , Animals , Cats , Cardiomyopathy, Hypertrophic/genetics , Heart Atria , Hypertrophy, Left Ventricular , Myocardium/metabolism , Myocardium/pathology , Disease Models, Animal
15.
J Int Bus Stud ; : 1-12, 2023 Jan 09.
Article in English | MEDLINE | ID: mdl-36685717

ABSTRACT

In response to Nachum et al.'s (J Int Bus Stud, 2023) call for further research in Africa by international business (IB) scholars, we argue that while IB scholars may have been slow to engage with Africa, the same cannot be said of related and IB-relevant business and management scholarship. There is already a substantial body of work on Africa in other domains of business and management scholarship - and relevant theorizing - that represents an important resource for IB scholarship. In contextualizing the 'interesting', we identify several contemporary theoretical strands that have so far characterized 'Africa research', interrogate ongoing challenges that mitigate these efforts, and suggest ways in which further research that speaks to theoretical, practical, and policy issues might inform IB researchers' engagement with Africa. Specifically, we set out the broader scope of the African business/management debate that might inform IB research, re-examine African diversity through the prism of 'theoretical tensions and puzzles', and consider the role of emergent indigenous theorizing such as ubuntu and Africapitalism that make Africa both 'interesting' and worthy of IB inquiry.


En réponse à l'appel lancé par Nachum et al. (2023) en faveur d'une intensification des recherches sur l'Afrique par les chercheurs en affaires internationales (International Business - IB), nous arguons que si les chercheurs en IB ont peut-être tardé à s'intéresser à l'Afrique, il n'en va pas de même pour ceux dans les disciplines du commerce et du management connexes et apparentées au domaine de l'IB. Il existe déjà un corps important de travaux sur l'Afrique dans d'autres domaines de la recherche en commerce et management - ainsi qu'une théorisation pertinente - qui constitue une grande ressource pour la recherche en IB. En contextualisant l'" intéressant ", nous identifions un certain nombre de courants théoriques contemporains qui ont jusqu'à présent caractérisé la " recherche sur l'Afrique ", nous interrogeons sur les défis actuels atténuant ces efforts, et suggérons les manières dont des recherches supplémentaires portées sur des questions politiques, pratiques et théoriques pourraient éclairer l'engagement des chercheurs en IB envers l'Afrique. Plus précisément, nous définissons la portée plus large du débat sur le commerce et le management en Afrique qui pourrait alimenter la recherche en IB, réexaminons la diversité africaine à travers le prisme des " tensions et énigmes théoriques ", et examinons le rôle de la théorisation indigène émergente, tels l'ubuntu et l'Africapitalisme qui rendent l'Afrique à la fois " intéressante " et digne d'être étudiée dans le domaine de l'IB.


En respuesta al llamamiento de Nachum et al. (2023) para que los especialistas en negocios internacionales realicen más investigaciones en África, afirmamos que, aunque los académicos en negocios internacionales hayan tardado en comprometerse con África, no puede decirse lo mismo de la investigación en negocios internacionales y de gestión. Ya existe un conjunto sustancial de trabajos sobre África en otros ámbitos de los negocios y la gestión -y una teorización relevante- que representa un recurso importante para los estudiosos de negocios internacionales. Al contextualizar lo "interesante", identificamos una serie de corrientes teóricas contemporáneas que han caracterizado hasta ahora la "investigación sobre África", interrogamos los desafíos actuales que mitigan estos esfuerzos y sugerimos formas en las que una mayor investigación que hable de cuestiones teóricas, prácticas y políticas podría informar el compromiso de los investigadores de negocios internacionales con África. En concreto, exponemos el alcance más amplio del debate sobre los negocios y la gestión en África que podría servir de base para la investigación sobre negocios internacionales, reexaminamos la diversidad africana a través del prisma de las "tensiones y los rompecabezas teóricos" y consideramos el papel de las teorías autóctonas emergentes, como el ubuntu y el africapitalismo, que hacen que África sea "interesante" y digna de ser investigada por negocios internacionales.


Em resposta ao pedido de Nachum et al. (2023) para pesquisas adicionais na África por acadêmicos de negócios internacionais (IB), argumentamos que, embora acadêmicos de IB possam ter sido tardios ao se envolver com a África, o mesmo não pode ser dito sobre estudos relevantes e relacionados a IB sobre gestão e negócios. Já existe um conjunto substancial de trabalhos sobre África em outros domínios da pesquisa em gestão e negócios - e desenvolvimento teórico relevante - que representa um recurso importante para a pesquisa em IB. Ao contextualizar o "interessante", identificamos uma série de vertentes teóricas contemporâneas que até agora caracterizaram a "pesquisa sobre África", interrogamos desafios correntes que mitigam esses esforços e sugerimos maneiras pelas quais pesquisas adicionais que tratem de questões teóricas, práticas e políticas possam balizar o envolvimento de pesquisadores em IB com a África. Especificamente, estabelecemos o escopo mais amplo do debate africano sobre gestão e negócios que pode balizar a pesquisa em IB, reexaminamos a diversidade africana através do prisma de "tensões teóricas e enigmas" e consideramos o papel da emergente teorização nativa, como o ubuntu e o africapitalismo, que tornam a África "interessante" e digna de investigação em IB.

16.
Int J Mol Sci ; 24(2)2023 Jan 04.
Article in English | MEDLINE | ID: mdl-36674412

ABSTRACT

Neutrophils have conflicting roles in the context of cancers, where they have been associated with contributing to both anti-tumor and pro-tumor responses. Their functional heterogenicity is plastic and can be manipulated by environmental stimuli, which has fueled an area of research investigating therapeutic strategies targeting neutrophils. Dendritic cell (DC)-based cancer vaccination is an immunotherapy that has exhibited clinical promise but has shown limited clinical efficacy. Enhancing our understanding of the communications occurring during DC cancer vaccination can uncover opportunities for enhancing the DC vaccine platform. There have been observed communications between neutrophils and DCs during natural immune responses. However, their crosstalk has been poorly studied in the context of DC vaccination. Here, we review the dual functionality of neutrophils in the context of cancers, describe the crosstalk between neutrophils and DCs during immune responses, and discuss their implications in DC cancer vaccination. This discussion will focus on how neutrophil extracellular traps can influence immune responses in the tumor microenvironment and what roles they may play in promoting or hindering DC vaccine-induced anti-tumor efficacy.


Subject(s)
Cancer Vaccines , Extracellular Traps , Hematologic Neoplasms , Neoplasms , Sarcoma , Humans , Neutrophils , Neoplasms/pathology , Dendritic Cells , Vaccination , Tumor Microenvironment
17.
J Exp Clin Cancer Res ; 42(1): 2, 2023 Jan 02.
Article in English | MEDLINE | ID: mdl-36588164

ABSTRACT

BACKGROUND: PCSK9 regulates cholesterol homeostasis and promotes tumorigenesis. However, the relevance of these two actions and the mechanisms underlying PCSK9's oncogenic roles in melanoma and other cancers remain unclear. METHODS: PCSK9's association with melanoma was analysed using the TCGA dataset. Empty vector (EV), PCSK9, gain-of-function (D374Y), and loss-of-function (Q152H) PCSK9 mutant were stably-expressed in murine melanoma B16 cells and studied for impact on B16 cell-derived oncogenesis in vitro and in vivo using syngeneic C57BL/6 and Pcsk9-/- mice. Intratumoral accumulation of cholesterol was determined. RNA-seq was performed on individual tumor types. Differentially-expressed genes (DEGs) were derived from the comparisons of B16 PCSK9, B16 D374Y, or B16 Q152H tumors to B16 EV allografts and analysed for pathway alterations. RESULTS: PCSK9 expression and its network negatively correlated with the survival probability of patients with melanoma. PCSK9 promoted B16 cell proliferation, migration, and growth in soft agar in vitro, formation of tumors in C57BL/6 mice in vivo, and accumulation of intratumoral cholesterol in a manner reflecting its regulation of the low-density lipoprotein receptor (LDLR): Q152H, EV, PCSK9, and D374Y. Tumor-associated T cells, CD8 + T cells, and NK cells were significantly increased in D374Y tumors along with upregulations of multiple immune checkpoints, IFNγ, and 143 genes associated with T cell dysfunction. Overlap of 36 genes between the D374Y DEGs and the PCSK9 DEGs predicted poor prognosis of melanoma and resistance to immune checkpoint blockade (ICB) therapy. CYTH4, DENND1C, AOAH, TBC1D10C, EPSTI1, GIMAP7, and FASL (FAS ligand) were novel predictors of ICB therapy and displayed high level of correlations with multiple immune checkpoints in melanoma and across 30 human cancers. We observed FAS ligand being among the most robust biomarkers of ICB treatment and constructed two novel and effective multigene panels predicting response to ICB therapy. The profiles of allografts produced by B16 EV, PCSK9, D374Y, and Q152H remained comparable in C57BL/6 and Pcsk9-/- mice. CONCLUSIONS: Tumor-derived PCSK9 plays a critical role in melanoma pathogenesis. PCSK9's oncogenic actions are associated with intratumoral cholesterol accumulation. PCSK9 systemically affects the immune system, contributing to melanoma immune evasion. Novel biomarkers derived from the PCSK9-network effectively predicted ICB therapy responses.


Subject(s)
Melanoma, Experimental , Melanoma , Humans , Mice , Animals , Proprotein Convertase 9/genetics , Fas Ligand Protein , Mice, Inbred C57BL , Melanoma/genetics , Melanoma, Experimental/genetics , Melanoma, Experimental/pathology , Cell Adhesion Molecules , Guanine Nucleotide Exchange Factors , GTPase-Activating Proteins
18.
Front Immunol ; 13: 1038340, 2022.
Article in English | MEDLINE | ID: mdl-36466867

ABSTRACT

Novel immunotherapies continue to be developed and tested for application against a plethora of diseases. The clinical translation of immunotherapies requires an understanding of their mechanisms. The contributions of antibodies in driving long-term responses following immunotherapies continue to be revealed given their diverse effector functions. Developing an in-depth understanding of the role of antibodies in treatment efficacy is required to optimize immunotherapies and improve the chance of successfully translating them into the clinic. However, analyses of antibody responses can be challenging in the context of antigen-agnostic immunotherapies, particularly in the context of cancers that lack pre-defined target antigens. As such, robust methods are needed to evaluate the capacity of a given immunotherapy to induce beneficial antibody responses, and to identify any therapy-limiting antibodies. We previously developed a comprehensive method for detecting antibody responses induced by antigen-agnostic immunotherapies for application in pre-clinical models of vaccinology and cancer therapy. Here, we extend this method to a high-throughput, flow cytometry-based assay able to identify and quantify isotype-specific virus- and tumor-associated antibody responses induced by immunotherapies using small sample volumes with rapid speed and high sensitivity. This method provides a valuable and flexible protocol for investigating antibody responses induced by immunotherapies, which researchers can use to expand their analyses and optimize their own treatment regimens.


Subject(s)
Immunotherapy , Neoplasms , Humans , Flow Cytometry , Antibodies , Neoplasms/therapy , Biological Assay
19.
Vet Sci ; 9(10)2022 Oct 04.
Article in English | MEDLINE | ID: mdl-36288160

ABSTRACT

Cancer is a significant cause of morbidity and mortality in domestic cats. In humans, an understanding of the oncogenome of different cancer types has proven critical and is deeply interwoven into all aspects of patient care, including diagnostics, prognostics and treatments through the application of targeted therapies. Investigations into understanding the genetics of feline cancers started with cytogenetics and was then expanded to studies at a gene-specific level, looking for mutations and expression level changes of genes that are commonly mutated in human cancers. Methylation studies have also been performed and together with a recently generated high-quality reference genome for cats, next-generation sequencing studies are starting to deliver results. This review summarises what is currently known of the genetics of both common and rare cancer types in cats, including lymphomas, mammary tumours, squamous cell carcinomas, soft tissue tumours, mast cell tumours, haemangiosarcomas, pulmonary carcinomas, pancreatic carcinomas and osteosarcomas. Shining a spotlight on our current understanding of the feline oncogenome will hopefully serve as a springboard for more much-needed research into the genetics of cancer in domestic cats.

20.
PLoS One ; 17(9): e0273811, 2022.
Article in English | MEDLINE | ID: mdl-36174075

ABSTRACT

Urokinase plasminogen activator (uPA) and its receptor uPAR promote cancer invasion and metastasis and are emerging therapeutic targets in both human and canine malignancies. While their clinical significance is well-characterized in multiple human tumor types, studies investigating their roles in osteosarcoma are lacking. The objectives of this study were to characterize serum and tissue uPA/uPAR expression in dogs with osteosarcoma and assess the prognostic significance. Serum samples and a tissue microarray of canine appendicular osteosarcoma were analyzed for uPA and uPAR expression by ELISA (n = 49) and immunohistochemistry (n = 38), respectively. Serum uPA activity was also measured by a chromogenic assay (n = 25). Survival analysis was performed by Kaplan-Meier survival analysis, log rank test, and Cox regression analysis. Serum uPA level was significantly higher in dogs with osteosarcoma than clinically healthy control dogs (median 1905 vs 1440 pg/ml, p = 0.008). The majority of canine osteosarcoma tissues expressed uPA (75.9%) or uPAR (77.6%), with 70.7% dual-positivity, indicating autocrine/paracrine activation of the pathway. Survival analysis revealed shorter progression free survival (PFS) in dogs with high serum uPA level in a discovery cohort (n = 29; median PFS 94 vs 266 days, p = 0.003) but not in a validation cohort (n = 23; median PFS 167 vs 490 days, p = 0.16). The difference was significant when both cohorts were combined (n = 49; median PFS 128 vs 266 days, p = 0.003). Serum uPAR and tissue uPA/uPAR levels were not prognostic. In Cox multivariate analysis, high serum uPA level and activity were both associated with poor prognosis, independent of serum ALP, tumor location, and peripheral lymphocyte/monocyte counts. These results indicate high utilization of the uPA pathway and association with disease progression in canine osteosarcoma. Further study involving prospective evaluation to confirm the prognostic significance is warranted. The high prevalence of tissue uPA and uPAR expression suggests the uPA system as a potential therapeutic target in canine osteosarcoma.


Subject(s)
Appendix , Bone Neoplasms , Osteosarcoma , Animals , Bone Neoplasms/veterinary , Dogs , Humans , Osteosarcoma/veterinary , Progression-Free Survival , Urokinase-Type Plasminogen Activator
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