Search results for "Phosphorylation"
showing 10 items of 975 documents
Loss of p53 Attenuates the Contribution of IL-6 Deletion on Suppressed Tumor Progression and Extended Survival in Kras-Driven Murine Lung Cancer
2013
Interleukin-6 (IL-6) is involved in lung cancer tumorigenesis, tumor progression, metastasis, and drug resistance. Previous studies show that blockade of IL-6 signaling can inhibit tumor growth and increase drug sensitivity in mouse models. Clinical trials in non-small cell lung cancer (NSCLC) reveal that IL-6 targeted therapy relieves NSCLC-related anemia and cachexia, although other clinical effects require further study. We crossed IL-6(-/-) mice with Kras(G12D) mutant mice, which develop lung tumors after activation of mutant Kras(G12D), to investigate whether IL-6 inhibition contributes to tumor progression and survival time in vivo. Kras(G12D); IL-6(-/-) mice exhibited increased tumor…
Western blotting as a method for studying cell-biomaterial interactions: The role of protein collection
2000
Research of cell-biomaterial interactions is building on knowledge and methods available in cell and molecular biology. Western blotting is one of the options to characterize protein expression in cell populations. Method transfer to biomaterial model systems is not trivial because of the structure that exists in many biomaterials, preventing the collection of cell lysate by mechanical means. In this technical report, we describe the influence of different protein collection methods in a model system for cell-biomaterial interactions, consisting of endothelial cells exposed to different stimuli. In particular, the influence of trypsinization before lysis, and handling complexity were determ…
Coupling of Contact Sensitizers to Thiol Groups is a Key Event for the Activation of Monocytes and Monocyte-Derived Dendritic Cells
2003
Strong contact sensitizers are able to induce distinct signal transduction mechanisms in antigen-presenting cells by coupling to cell proteins. The predominant target structures of haptens are thought to be thiol and amino groups in cysteine and lysine residues. We studied whether coupling of small reactive chemicals to thiol or amino groups might be responsible for the activation of monocytes and mature monocyte-derived dendritic cells. Human peripheral blood mononuclear cells were stimulated in vitro with subtoxic concentrations of the strong haptens 5-chloro-2-methylisothiazolinone plus 2-methylisothiazolinone and 2, 4, 6-trinitrochlorobenzene, the thiol-reactive reagents N-hydroxymaleim…
p38 MAPK-dependent shaping of the keratin cytoskeleton in cultured cells
2007
Plasticity of the resilient keratin intermediate filament cytoskeleton is an important prerequisite for epithelial tissue homeostasis. Here, the contribution of stress-activated p38 MAPK to keratin network organization was examined in cultured cells. It was observed that phosphorylated p38 colocalized with keratin granules that were rapidly formed in response to orthovanadate. The same p38p recruitment was noted during mitosis, in various stress situations and in cells producing mutant keratins. In all these situations keratin 8 became phosphorylated on S73, a well-known p38 target site. To demonstrate that p38-dependent keratin phosphorylation determines keratin organization, p38 activity …
Neuroprotection elicited by P2Y13 receptors against genotoxic stress by inducing DUSP2 expression and MAPK signaling recovery.
2014
AbstractNucleotides activating P2Y13 receptors display neuroprotective actions against different apoptotic stimuli in cerebellar granule neurons. In the present study, P2Y13 neuroprotection was analyzed in conditions of genotoxic stress. Exposure to cisplatin and UV radiation induced caspase-3-dependent apoptotic cell death, and p38 MAPK signaling de-regulation. Pre-treatment with P2Y13 nucleotide agonist, 2methyl-thio-ADP (2MeSADP), restored granule neuron survival and prevented p38 long-lasting activation induced by cytotoxic treatments. Microarray gene expression analysis in 2MeSADP-stimulated cells revealed over-representation of genes related to protein phosphatase activity. Among them…
The three α1-adrenoceptor subtypes show different spatio-temporal mechanisms of internalization and ERK1/2 phosphorylation
2013
AbstractWe analyzed the kinetic and spatial patterns characterizing activation of the MAP kinases ERK 1 and 2 (ERK1/2) by the three α1-adrenoceptor (α1-AR) subtypes in HEK293 cells and the contribution of two different pathways to ERK1/2 phosphorylation: protein kinase C (PKC)-dependent ERK1/2 activation and internalization-dependent ERK1/2 activation. The different pathways of phenylephrine induced ERK phosphorylation were determined by western blot, using the PKC inhibitor Ro 31-8425, the receptor internalization inhibitor concanavalin A and the siRNA targeting β-arrestin 2. Receptor internalization properties were studied using CypHer5 technology and VSV-G epitope-tagged receptors. Activ…
Eicosapentaenoic acid and docosahexaenoic acid modulate MAP kinase (ERK1/ERK2) signaling in human T cells
2001
This study was conducted on human Jurkat T cell lines to elucidate the role of EPA and DHA, n-3 PUFA, in the modulation of two mitogen-activated protein (MAP) kinases, that is, extracellular signal-regulated kinases 1 and 2 (ERK1 and ERK2). The n-3 PUFA alone failed to induce phosphorylation of ERK1/ERK2. We stimulated the MAP kinase pathway with anti-CD3 antibodies and phorbol 12-myristate 13-acetate (PMA), which act upstream of the MAP kinase (MAPK)/ERK kinase (MEK) as U0126, an MEK inhibitor, abolished the actions of these two agents on MAP kinase activation. EPA and DHA diminished the PMA- and anti-CD3-induced phosphorylation of ERK1/ERK2 in Jurkat T cells. In the present study, PMA act…
Potentiation of the antitumor effects of both selective cyclooxygenase-1 and cyclooxygenase-2 inhibitors in human hepatic cancer cells by inhibition …
2007
The molecular mechanisms behind the anti-neoplastic effects of non-steroidal anti-inflammatory drugs (NSAIDs) are not completely understood and cannot be explained by the inhibition of the cyclooxygenase (COX) enzymes COX-1 and COX-2 alone. We previously reported that both the selective COX-1 inhibitor SC-560 and the selective COX-2 inhibitor CAY10404 exhibit anti-tumor effects in human hepatoma cells. NSAID inhibitors have many COX-independent actions and, among others, the mitogen-activated protein kinase (MAPK) pathways are targets for NSAIDs. Here, we examined the role of MEK/ERK1/2 signaling in the anti-neoplastic effects of both selective COX-1 and COX-2 inhibitors in two human hepato…
Mevalonate pathway inhibitors affect anticancer drug-induced cell death and DNA damage response of human sarcoma cells
2011
Lovastatin (Lov), bisphosphonates (BP) and metformin (Met) are widely used drugs, having in common that they interfere with the mevalonate pathway (MP). The MP generates isoprene moieties required for the function of regulatory GTPases controlling cell proliferation and survival. Here, we addressed the question whether MP inhibitors interfere with the anti-tumor efficacy of anticancer drugs. We comparatively analyzed the effect of equitoxic doses of Lov, BP and Met on cell viability, cell cycle progression, apoptosis and DNA damage response (DDR) of human osteo- and fibrosarcoma cells exposed to doxorubicin or cisplatin. We found that Lov, BP and Met modulated the anticancer drug sensitivit…
Interferon-α Suppresses cAMP to Disarm Human Regulatory T Cells
2013
Abstract IFN-α is an antineoplastic agent in the treatment of several solid and hematologic malignancies that exerts strong immune- and autoimmune-stimulating activity. However, the mechanisms of immune activation by IFN-α remain incompletely understood, particularly with regard to CD4+CD25highFoxp+ regulatory T cells (Treg). Here, we show that IFN-α deactivates the suppressive function of human Treg by downregulating their intracellular cAMP level. IFN-α–mediated Treg inactivation increased CD4+ effector T-cell activation and natural killer cell tumor cytotoxicity. Mechanistically, repression of cAMP in Treg was caused by IFN-α–induced MAP–ERK kinase (MEK)/extracellular signal-regulated ki…