38 research outputs found

    The chemopreventive retinoid 4HPR impairs prostate cancer cell migration and invasion by interfering with FAK/AKT/GSK3β pathway and β-catenin stability

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    <p>Abstract</p> <p>Background</p> <p>Prostate cancer shows an extremely slow progression, appearing in its metastatic, hormone refractory phenotype mostly in elderly men. The chemopreventive targeting of this tumor could accordingly delay its malignancy over life expectancy. The cancer chemopreventive retinoid <it>N</it>-(4 hydroxyphenyl)retinamide (4HPR) has already been shown to restrain prostate cancer growth in vitro and in vivo, though its mechanisms of action are only partially explained.</p> <p>Results</p> <p>We found that 4HPR impairs DU145 and PC3 prostate cancer cells migration and invasion by down-regulating FAK and AKT activation and by enhancing β-catenin degradation, causing the downregulation of target genes like cyclin D1, survivin and VEGF. This non-migratory phenotype was similarly produced in both cell lines by stable silencing of β-catenin. 4HPR was able to decrease AKT phosphorylation also when powerfully upregulated by IGF-1 and, consequently, to impair IGF-1-stimulated cell motility. Conversely, the expression of constitutively active AKT (myr-AKT) overcame the effects of 4HPR and β-catenin-silencing on cell migration. In addition, we found that BMP-2, a 4HPR target with antiangiogenic activity, decreased prostate cancer cell proliferation, migration and invasion by down-regulating the pathway described involving AKT phosphorylation, β-catenin stability and cyclin D1 expression.</p> <p>Conclusion</p> <p>These data point to 4HPR as a negative regulator of AKT phosphorylation, effectively targeting the β-catenin pathway and inducing a relatively benign phenotype in prostate cancer cells, limiting neoangiogenesis and cell invasion.</p

    ADAM10 new selective inhibitors reduce NKG2D ligand release sensitizing Hodgkin lymphoma cells to NKG2D-mediated killing

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    Hodgkin lymphoma (HL) resistant to conventional therapies is increasing, making of interest the search for new schemes of treatment. Members of the “A Disintegrin And Metalloproteases” (ADAMs) family, mainly ADAM10 or ADAM17, have been proposed as therapeutic targets in solid tumors and some ADAMs inhibitors have been shown to exert antitumor effects. We have previously described an overexpression of ADAM10 in HL, together with increased release of NKG2D ligands (NKG2D-L) and reduced activation of effector T lymphocytes with anti-lymphoma capacity. Aim of the present work was to verify whether inhibition of ADAM10 in HL cells could restore the triggering of NKG2D-dependent anti-lymphoma T cell response. As no selective ADAM10 blockers have been reported so far, we synthesized the two hydroxamate compounds LT4 and MN8 with selectivity for ADAM10 over metalloproteases (MMPs), LT4 showing higher specificity for ADAM10 over ADAM17. We show that (i) HL lymph nodes (LN) and cultured HL cells express high levels of the mature active membrane form of ADAM10; (ii) ADAM10 is the major sheddase for the NKG2D-L in HL cells; (iii) the new LT4 and MN8 compounds strongly reduce the shedding of NKG2D-L by HL cell lines and enhance the binding of NKG2D receptor; (iv) of note, these new ADAM10 inhibitors increase the sensitivity of HL cell lines to NKG2D-dependent cell killing exerted by natural killer and γδ T cells. Overall, the biologic activity of LT4 and MN8 appears to be more potent than that of the commercial inhibitor GI254023X

    Specific ADAM10 inhibitors localize in exosome-like vesicles released by Hodgkin lymphoma and stromal cells and prevent sheddase activity carried to bystander cells

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    Shedding of ADAM10 substrates, like TNFa, MICA or CD30, is reported to affect both anti-tumor immune response and antibody-drug-conjugate (ADC)-based immunotherapy. Soluble forms of these molecules and ADAM10 can be carried and spread in the microenvironment by exosomes released by tumor cells. We reported new ADAM10 inhibitors able to prevent MICA shedding in Hodgkin lymphoma (HL), leading to recognition of HL cells by cytotoxic lymphocytes. In this paper, we show that the mature bioactive form of ADAM10 is released in exosome-like vesicles (ExoV) by HL cells and lymph node mesenchymal stromal cells (MSC). We demonstrate that ADAM10 inhibitors are released in ExoV by MSC or HL cells, endocytosed by bystander cells and localized in the endolysosomal compartment in HL MSC. ExoV released by HL cells can enhance MICA shedding by MSC, while ExoV from MSC induce TNFa or CD30 shedding by HL cells. Of note, ADAM10 sheddase activity carried by ExoV is prevented with the ADAM10 inhibitors LT4 and CAM29, pretreating either the ExoVproducing or the ExoV-receiving cells. In particular, both inhibitors reduce CD30 shedding maintaining the anti-tumor effects of the ADC Brentuximab-Vedotin or the anti-CD30 Iratumumab on HL cells. Thus, spreading of ADAM10 activity due to ExoV can result in the release of cytokines, like TNFa,a lymphoma growth factor, or soluble molecules, like sMICA or sCD30, that potentially interfere with host immune surveillance or immunotherapy. ADAM10 blockers can interfere with this process, allowing the development of anti-lymphoma immune response and/or efficient ADC-based or human antibody-based immunotherapy

    Human Gut-Associated Natural Killer Cells in Health and Disease

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    It is well established that natural killer (NK) cells are involved in both innate and adaptive immunity. Indeed, they can recognize molecules induced at the cell surface by stress signals and virus infections. The functions of NK cells in the gut are much more complex. Gut NK cells are not precisely organized in lymphoid aggregates but rather scattered in the epithelium or in the stroma, where they come in contact with a multitude of antigens derived from commensal or pathogenic microorganisms in addition to components of microbiota. Furthermore, NK cells in the bowel interact with several cell types, including epithelial cells, fibroblasts, macrophages, dendritic cells, and T lymphocytes, and contribute to the maintenance of immune homeostasis and development of efficient immune responses. NK cells have a key role in the response to intestinal bacterial infections, primarily through production of IFNγ, which can stimulate recruitment of additional NK cells from peripheral blood leading to amplification of the anti-bacterial immune response. Additionally, NK cells can have a role in the pathogenesis of gut autoimmune inflammatory bowel diseases (IBDs), such as Crohn's Disease and Ulcerative Colitis. These diseases are considered relevant to the generation of gastrointestinal malignancies. Indeed, the role of gut-associated NK cells in the immune response to bowel cancers is known. Thus, in the gut immune system, NK cells play a dual role, participating in both physiological and pathogenic processes. In this review, we will analyze the known functions of NK cells in the gut mucosa both in health and disease, focusing on the cross-talk among bowel microenvironment, epithelial barrier integrity, microbiota, and NK cells

    Através da língua portuguesa: da História sociopolítica da língua portuguesa de C. A. Faraco (tradução português-italiano) à apropriação do Português Língua Não Materna por um público ucraniano, entre passado e futuro

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    L'elaborato consiste nella traduzione dal portoghese all'italiano (Apresentação, Capítulo Um, Capítulo Três) dell'opera di Carlos Alberto Faraco "História sociopolítica da língua portuguesa", accompagnata dal commento critico alla traduzione, e seguita da un breve saggio che, partendo da un'introduzione teorica sull'acquisizione/apprendimento linguistico in età adulta, presenta il progetto "Aproximações à Língua Portuguesa: atitudes e discursos de não nativos residentes em Portugal (POCI/CED/56110/2004)", concentrandosi sulla comunità di immigrati ucraini analizzata, per poi proporre nuove linee di ricerca sull'appropriazione della lingua portoghese da parte di immigrati ucraini, considerando le nuove circostanze dell'immigrazione ucraina in Portogallo in conseguenza dell'invasione territoriale russa dell'Ucraina, iniziata nel 2022. The paper consists of a translation from Portuguese to Italian (Apresentação, Capítulo Um, Capítulo Três) of Carlos Alberto Faraco's work "História sociopolítica da língua portuguesa," accompanied by critical commentary on the translation, and followed by a short essay that, starting with a theoretical introduction on language acquisition/learning in adulthood, presents the project "Aproximações à Língua Portuguesa: atitudes e discursos de não nativos residentes em Portugal (POCI/CED/56110/2004)," focusing on the Ukrainian immigrant community analyzed, and then proposes new lines of research on the appropriation of the Portuguese language by Ukrainian immigrants, considering the new circumstances of Ukrainian immigration to Portugal as a result of the Russian territorial invasion of Ukraine, which began in 2022

    Le potenzialità dell'insegnante creativo. L'influenza dell'ambiente culturale nei contesti formativi.

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    Consapevoli dell'importanza che la creatività ha rivestito in passato e rivestirà nel futuro in tutti gli ambiti di interesse umano, questa tesi si concentra sulla promozione della creatività nell'ambiente scolastico attraverso tre principali ambiti di studio. Nel primo capitolo, si esamina la storia degli studi sulla creatività, passando dalla psicologia e arrivando al neuroimaging. Nel secondo capitolo, partendo dalla comprensione del funzionamento del processo creativo, si analizza l'intersezione tra creatività e pedagogia, includendo alcune riflessioni sull'intelligenza artificiale. Chiarito il ruolo dell'ambiente di apprendimento nell'influenzare la creatività, nel terzo capitolo si focalizza l'attenzione sulla creatività a scuola, esplorando il ruolo e le potenzialità di un insegnante creativo

    The Cystine/Cysteine Cycle and GSH Are Independent and Crucial Antioxidant Systems in Malignant Melanoma Cells and Represent Druggable Targets

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    Abstract Aims: Cancer chemoresistance is often due to upregulation of antioxidant systems. Therapeutic targeting of these systems is however hampered by their redundancy. Here, we have performed a functional dissection of the antioxidant systems in different melanoma cases aimed at the identification of the most effective redox active drug. Results: We have identified two crucial antioxidant mechanisms: glutathione (GSH), the major intracellular redox buffer, and the cystine/cysteine cycle, which switches the extracellular redox state from an oxidized to a reduced state. The two mechanisms are independent in melanoma cells and may be substitutes for each other, but targeting both of them is lethal. Exposure to the pro-oxidant compound As(2)O(3) induces an antioxidant response. However, while in these cells the intracellular redox balance remains almost unaffected, a reduced environment is generated extracellularly. GSH depletion by buthioninesulfoximine (BSO), or cystine/cysteine cycle inhibition by (S)-4-carboxyphenylglycine (sCPG), enhanced the sensitivity to As(2)O(3). Remarkably, sCPG also prevented the remodeling of the microenvironment redox state. Innovation: We propose that the definition of the prevalent antioxidant system(s) in tumors is crucial for the design of tailored therapies involving redox-directed drugs in association with pro-oxidant drugs. Conclusion: In melanoma cells, BSO is the best enhancer of As(2)O(3) sensitivity. However, since the strong remodeling of the microenvironmental redox state caused by As(2)O(3) may promote tumor progression, the concomitant use of cystine/cysteine cycle blockers is recommended. Antioxid. Redox Signal. 00, 000-000
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