Search results for "signaling proteins"
showing 10 items of 24 documents
Autocrine production of interleukin-4 and interleukin-10 is required for survival and growth of thyroid cancer cells.
2006
AbstractAlthough CD95 and its ligand are expressed in thyroid cancer, the tumor cell mass does not seem to be affected by such expression. We have recently shown that thyroid carcinomas produce interleukin (IL)-4 and IL-10, which promote resistance to chemotherapy through the up-regulation of Bcl-xL. Here, we show that freshly purified thyroid cancer cells were completely refractory to CD95-induced apoptosis despite the consistent expression of Fas-associated death domain and caspase-8. The analysis of potential molecules able to prevent caspase-8 activation in thyroid cancer cells revealed a remarkable up-regulation of cellular FLIPL (cFLIPL) and PED/PEA-15, two antiapoptotic proteins whos…
Expression of WISPs and of their novel alternative variants in human hepatocellular carcinoma cells
2005
WISPs (Wnt-induced secreted proteins) are members of the CCN (CTGF/Cyr61/Nov) family involved in fibrotic disorders and tumorigenesis. They have a typical structure composed of four conserved cysteine-rich modular domains, but variants of CCN members lacking one or more modules, generated by alternative splicing or gene mutations, have been described in various pathological conditions. WISP genes were first described as downstream targets of the Wnt signaling pathway, which is frequently altered in human hepatocellular carcinoma (HCC). In the present study, WISP mRNA expression was analyzed by RT-PCR in four human HCC cell lines (HepG2, HuH-6, HuH-7, HA22T/VGH). Our results show for the fir…
Cabut/dTIEG associates with the transcription factor Yorkie for growth control
2015
The Drosophila transcription factor Cabut/dTIEG (Cbt) is a growth regulator, whose expression is modulated by different stimuli. Here, we determine Cbt association with chromatin and identify Yorkie (Yki), the transcriptional co-activator of the Hippo (Hpo) pathway as its partner. Cbt and Yki co-localize on common gene promoters, and the expression of target genes varies according to changes in Cbt levels. Down-regulation of Cbt suppresses the overgrowth phenotypes caused by mutations in expanded (ex) and yki overexpression, whereas its up-regulation promotes cell proliferation. Our results imply that Cbt is a novel partner of Yki that is required as a transcriptional co-activator in growth…
Cross-Inhibition of Interferon-Induced Signals by GM-CSF Through a Block in Stat1 Activation
2007
We investigated the effects of granulocyte-macrophage colony-stimulating factor (GM-CSF) on biologic signals induced by interferon-alpha (IFN-alpha) and IFN-gamma. In hematopoietic cell lines, IFN-induced signaling was investigated by Western blotting, electrophoretic mobility shift assays (EMSA), flow cytometry, protein-tyrosine phosphatase (PTP) assays, and RT-PCR. GM-CSF inhibited IFN-alpha-induced and IFN-gamma-induced Stat1 tyrosine phosphorylation in a time-dependent manner. EMSA showed that GM-CSF inhibited IFN-alpha-induced and IFN-gamma-induced IFN-gamma activator sequence (GAS) binding activity. As a consequence, IFN-induced transcription of the early response gene, IFN-stimulated…
Inactivation of Socs3 in the Hypothalamus Enhances the Hindbrain Response to Endogenous Satiety Signals via Oxytocin Signaling.
2012
Leptin is an adipocyte-derived hormone that controls energy balance by acting primarily in the CNS, but its action is lost in common forms of obesity due to central leptin resistance. One potential mechanism for such leptin resistance is an increased hypothalamic expression of Suppressor of cytokine signaling 3 (Socs3), a feedback inhibitor of the Jak-Stat pathway that prevents Stat3 activation. Ample studies have confirmed the important role of Socs3 in leptin resistance and obesity. However, the degree to which Socs3 participates in the regulation of energy homeostasis in nonobese conditions remains largely undetermined. In this study, using adult mice maintained under standard diet, we d…
Interruption of Macrophage-Derived IL-27(p28) Production by IL-10 during Sepsis Requires STAT3 but Not SOCS3
2014
Abstract Severe sepsis and septic shock are leading causes of morbidity and mortality worldwide. Infection-associated inflammation promotes the development and progression of adverse outcomes in sepsis. The effects of heterodimeric IL-27 (p28/EBI3) have been implicated in the natural course of sepsis, whereas the molecular mechanisms underlying the regulation of gene expression and release of IL-27 in sepsis are poorly understood. We studied the events regulating the p28 subunit of IL-27 in endotoxic shock and polymicrobial sepsis following cecal ligation and puncture. Neutralizing Abs to IL-27(p28) improved survival rates, restricted cytokine release, and reduced bacterial burden in C57BL/…
A non-redundant role for OX40 in the competitive fitness of Treg in response to IL-2.
2010
OX40 stimulation is known to enhance activation of effector T cells and to inhibit induction and suppressive function of Treg. Here we uncovered a novel role of OX40 in sustaining Treg competitive fitness in vivo, during repopulation of lymphopenic hosts and reconstitution of BM chimeras. Defective expansion of OX40-null Treg diminished their ability to suppress inflammation in a model of lymphopenia-driven colitis. OX40-mediated promotion of Treg fitness spanned beyond lymphopenic environments, as endogenous Treg in OX40-null mice showed decreased accumulation during thymic development, enhanced susceptibility to antibody-mediated depletion and defective turnover following thymectomy. In v…
Differential expression of suppressors of cytokine signaling-1, -2, and -3 in the rat hippocampus after seizure: implications for neuromodulation by …
2003
Numerous studies have investigated the expression of various cytokine families in the CNS after brain injury. The gp130 or interleukin (IL)-6-type cytokines have received a great deal of focus, and it is clear that they exhibit an acute and robust upregulation in various brain injury models. We are interested to determine, however, whether endogenously expressed cytokines in the CNS act in a direct neuromodulatory manner. In an accompanying study, we examined the expression of five gp130 cytokines and their receptors in the lithium-pilocarpine model of status epilepticus. We follow up that study here by trying to determine if gp130 signal transduction occurs in hippocampal principal neurons…
Functional polymorphisms in SOCS1 and PTPN22 genes correlate with the response to imatinib treatment in newly diagnosed chronic-phase chronic myeloid…
2011
a b s t r a c t The function of the natural modulators of BCR-ABL-induced signaling pathways could influence the results to imatinib treatment. We assessed the association between single nucleotide polymorphisms (SNPs) on genes of the phosphatase family and the suppressors of cytokine signaling and the response to imatinib in 105 patients newly diagnosed with chronic-phase CML. SNPs in SOCS1 (rs243327) and PTPN22 (rs2476601) genes correlated with the risk of primary resistance to imatinib. A high-risk Sokal score, the T allele in PTPN22 SNP, and each copy of the C allele in SOCS1 SNP were adverse prognostic factors for failure-free survival (FFS). Based on such parameters, three risk groups…
Suppressor of cytokine signaling 3 sensitizes anaplastic thyroid cancer to standard chemotherapy
2009
We previously showed that cancer cells from papillary, follicular, and anaplastic thyroid carcinomas produce interleukin-4 and interleukin-10, which counteract the cytotoxic activity of conventional chemotherapy through the up-regulation of antiapoptotic molecules. Here, we identify Janus kinase/signal transducers and activators of transcription (STAT) and phosphatidyl inositol 3-kinase (PI3K)/AKT as the down-stream pathways through which these cytokines confer resistance to cell death in thyroid cancer. We found that the absence of suppressors of cytokine signaling (SOCS) molecules allows the propagation of the survival signaling. Exogenous expression of SOCS1, SOCS3, and SOCS5 in the high…