Publications by authors named "Enric Espel"

Objective: Cannabinoids are able to reduce tumor growth in xenograft models, but their therapeutic potential as anti-cancer drugs in humans is unclear yet. In vitro studies of the effect of cannabinoids on cancer cells are often carried out in absence of serum or in low serum concentration (i.e.

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The lymphocyte function-associated antigen-1 (LFA-1) (also known as CD11a/CD18 and αβ₂), is just one of many integrins in the human body, but its significance is derived from its exclusive presence in leukocytes. In this review, we summarize the studies relating LFA-1 and its major ligand ICAM-1 (or CD54) with cancer, through the function of lymphocytes and myeloid cells on tumor cells. We consider how LFA-1 mediates the interaction of leukocytes with tumors and the role of ICAM-1 in tumor dynamics, which can be independent of its interaction with LFA-1.

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Ataxia-telangiectasia mutated (ATM) is a cell cycle checkpoint kinase that upon activation by DNA damage leads to cell cycle arrest and DNA repair or apoptosis. The absence of Atm or the occurrence of loss-of-function mutations in Atm predisposes to tumorigenesis. MAPK7 has been implicated in numerous types of cancer with pro-survival and pro-growth roles in tumor cells, but its functional relation with tumor suppressors is not clear.

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An adequate supply of nucleotides is essential for accurate DNA replication, and inappropriate deoxyribonucleotide triphosphate (dNTP) concentrations can lead to replication stress, a common source of DNA damage, genomic instability and tumourigenesis. Here, we provide evidence that Erk5 is necessary for correct nucleotide supply during erythroid development. Mice with Erk5 knockout in the haematopoietic lineage showed impaired erythroid development in bone marrow, accompanied by altered dNTP levels and increased DNA mutagenesis in erythroid progenitors as detected by exome sequencing.

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Regulation of the levels of the TCR/CD3 complex at the cell surface is critical to proper T cell development and mature T cell activation. We provide evidence that the MAPK ERK5 regulates the surface expression of the TCR/CD3 complex by controlling the degradation of the CD3ζ chain and the recovery of the complex after anti-CD3ε stimulation. ERK5 knockdown led to TCR/CD3 up-regulation at the cell surface and increased amounts of the CD3ζ chain.

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Syndecans are cell membrane proteoglycans that can modulate the activity and dynamics of some growth factor receptors and integrins. Here, we show the down-regulation of integrin lymphocyte function-associated antigen-1 (LFA-1) and inhibition of adhesion of Jurkat T cells transfected with syndecan-2. The PDZ-binding domain in the cytoplasmic region of syndecan-2 was necessary to block the LFA-1 high-affinity conformation, and to reduce cellular adhesion.

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T cells express the heparan sulphate proteoglycans syndecan-2 and syndecan-4. Syndecan-4 plays a T-cell inhibitory role; however, the function of syndecan-2 is unknown. In an attempt to examine this function, syndecan-2 was expressed constitutively in Jurkat T cells.

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Purpose: The goal of this study was to characterize and compare mesenchymal stem cells from adult human adipose tissue (ADS cells) with progenitor cell lines from the human corneoscleral limbus and to analyze their potential for the expression of epithelial markers.

Methods: Stem cell markers (CD34, CD90, p63, and ABCG2) and epithelial cell markers (CK3/76, CK12, CK76, CK19, and CK1/5/10/14) were analyzed by immunostaining, flow cytometry, Western blot analysis, and PCR methods. The authors assayed adhesion and proliferation on different extracellular matrix proteins.

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Syndecans bind to cell adhesion molecules, growth factors and cytokines, and can act as coreceptors, and in this way modulate leukocyte cell function. Here, expression of the syndecans on primary human CD4 T cells was examined. Cell stimulation dramatically increased the amount of syndecan-4, and in a lower extent that of syndecan-2.

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Posttranscriptional regulatory mechanisms control TNFalpha expression through AU-rich elements in the 3'UTR of its mRNA. This is mediated through Erk and p38 MAP kinase signaling, although the mechanisms involved remain poorly understood. Here, we show that the MAP kinase signal-integrating kinases (Mnks), which are activated by both these pathways, regulate TNFalpha expression in T cells via the 3'UTR.

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The gene encoding the human TNF alpha receptor (TNFR) 2 contains polymorphisms in the 3' untranslated region (UTR). Previous studies have shown that some variant alleles in this region are associated with obesity and insulin resistance. However, the effect of these polymorphisms on the expression of TNFR2 has not been studied to date.

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Adenosine- and uridine-rich elements (AREs) located in 3'-untranslated regions are the best-known determinants of RNA instability. These elements have also been shown to control translation in certain mRNAs, including mRNAs for prominent pro-inflammatory and tumor growth-related proteins, and physiological anti-inflammatory processes that target ARE-controlled translation of mRNAs coding for pro-inflammatory proteins have been described. A major research effort is now being made to understand the mechanisms by which the translation of these mRNAs is controlled and the signalling pathways involved.

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Tumor necrosis factor alpha (TNF-alpha), a proinflammatory cytokine, is produced abundantly by monocytes and macrophages. We have compared LPS-stimulated TNF-alpha production and regulation in freshly isolated human monocytes and macrophages differentiated in vitro. A significant increase in LPS-induced TNF-alpha protein secretion was observed in macrophages over freshly isolated monocytes without comparable differences in TNF-alpha mRNA induction.

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