References of "Chau, Tieu-Lan"
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See detailTargeting osteopontin suppresses glioblastoma stem-like cell character and tumorigenicity in vivo
Lamour, Virginie; Henry, Aurélie ULg; Kroonen, Jerome et al

in International Journal of Cancer = Journal International du Cancer (2015)

Osteopontin (OPN) is a secreted protein involved in most aspects of tumor progression and metastasis development. Elevated OPN expression has been reported in multiple types of cancer including ... [more ▼]

Osteopontin (OPN) is a secreted protein involved in most aspects of tumor progression and metastasis development. Elevated OPN expression has been reported in multiple types of cancer including glioblastoma (GBM), the highest grade and most aggressive brain tumor. GBMs contain a subpopulation of glioma-initiating cells (GICs) implicated in progression, therapeutic resistance and recurrence. We have previously demonstrated that OPN silencing inhibited GBM cell growth in vitro and in vivo. Moreover, activation of CD44 signaling upon OPN ligation has been recently implicated in the acquisition of a stem cell phenotype by GBM cells. The present study is aimed to explore OPN autocrine function using shRNA silencing strategy in GICs enriched from GBM cell lines and a human primary GBM grown in EGF and bFGF defined medium. The removal of these growth factors and addition of serum induced a significant loss of OPN expression in GICs. We showed that OPN-silenced GICs were unable to grow as spheres and this capacity was restored by exogenous OPN. Importantly, the expression of Sox2, Oct3/4 and Nanog, key stemness transcription factors, was significantly decreased in GICs upon OPN targeting. We identified Akt/mTOR/p70S6K as the main signaling pathway triggered following OPN-mediated EGFR activation in GICs. Finally, in an orthotopic xenograft mouse model, the tumorigenic potential of U87-MG sphere cells was completely abrogated upon OPN silencing. Our demonstration of endogenous OPN major regulatory effects on GICs stemness phenotype and tumorigenicity implies a greater role than anticipated for OPN in GBM pathogenesis from initiation and progression to probable recurrence. [less ▲]

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See detailA Role for APPL1 in TLR3/4-dependent TBK1 and IKKe activation in macrophages
Chau, Tieu-Lan ULg; Göktuna, Serkan ULg; Rammal, Ayman et al

in Journal of Immunology (2015)

Endosomes have important roles in intracellular signal transduction as a sorting platform. Signaling cascades from TLR engagement to IRF3-dependent gene transcription rely on endosomes, yet the proteins ... [more ▼]

Endosomes have important roles in intracellular signal transduction as a sorting platform. Signaling cascades from TLR engagement to IRF3-dependent gene transcription rely on endosomes, yet the proteins that specifically recruit IRF3-activating molécules to them are poorly defined. We show that adaptor protein containing a pleckstrin-homology domain, a phosphotyrosine-binding domain, and a leucine zipper motif (APPL)1, an early endosomal protein, is required for both TRIF- and retinoic acid–inducible gene 1–dependent signaling cascades to induce IRF3 activation. APPL1, but not early endosome Ag 1, deficiency impairs IRF3 target gene expression upon engagement of both TLR3 and TLR4 pathways, as well as in H1N1-infected macrophages. The IRF3-phosphorylating kinases TBK1 and IKK« are recruited to APPL1 endosomes in LPS-stimulated macrophages. Interestingly, APPL1 undergoes proteasome-mediated degradation through ERK1/2 to turn off signaling. APPL1 degradation is blocked when signaling through the endosome is inhibited by chloroquine or dynasore. Therefore, APPL1 endosomes are critical for IRF3-dependent gene expression in response to some viral and bacterial infections in macrophages. Those signaling pathways involve the signal-induced degradation of APPL1 to prevent aberrant IRF3-dependent gene expression linked to immune diseases. [less ▲]

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See detailAre the IKKs and IKK-related kinases TBK1 and IKK-ε similarly activated ?
Chau, Tieu-Lan ULg; Gioia, Romain ULg; GATOT, Jean-Stéphane ULg et al

in Trends in Biochemical Sciences - Regular Edition (2008), 33

The IKKs, IKKa and IKKb, and the IKK-related kinases TBK1 and IKKe, play essential roles in innate immunity through signal-induced activation of NF-κB and IRF3/7, respectively. Although the signaling ... [more ▼]

The IKKs, IKKa and IKKb, and the IKK-related kinases TBK1 and IKKe, play essential roles in innate immunity through signal-induced activation of NF-κB and IRF3/7, respectively. Although the signaling events within these pathways have been extensively studied, the mechanisms of IKK and IKK-related complex assembly and activation remain poorly defined. Recent data provide insight into the requirement for scaffold proteins in complex assembly; NEMO coordinates some IKK complexes, whereas TANK, NAP1 or SINTBAD assemble TBK1 and IKKe complexes. The different scaffold proteins undergo similar post-translational modifications, including phosphorylation and non-degradative polyubiquitylation. Moreover, increasing evidence suggests that distinct scaffold proteins assemble IKK and potentially TBK1 and IKKε sub-complexes in a stimulus-specific manner, which might be a mechanism to achieve specificity. [less ▲]

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See detailTLR-4, IL-1R and TNF-R signaling to NF-kB: variations on a common theme
Verstrepen, L.; Bekaert, T.; Chau, Tieu-Lan ULg et al

in Cellular and Molecular Life Sciences : CMLS (2008), 65

Toll-like receptors (TLRs) as well as the receptors for tumor necrosis factor (TNF-R) and interleukin-1 (IL-1R) play an important role in innate immunity by regulating the activity of distinct ... [more ▼]

Toll-like receptors (TLRs) as well as the receptors for tumor necrosis factor (TNF-R) and interleukin-1 (IL-1R) play an important role in innate immunity by regulating the activity of distinct transcription factors such as nuclear factor-kappaB (NF-kappaB). TLR, IL-1R and TNF-R signaling to NF-kappaB converge on a common IkappaB kinase complex that phosphorylates the NF-kappaB inhibitory protein IkappaBalpha. However, upstream signaling components are in large part receptor-specific. Nevertheless, the principles of signaling are similar, involving the recruitment of specific adaptor proteins and the activation of kinase cascades in which protein-protein interactions are controlled by poly-ubiquitination. In this review, we will discuss our current knowledge of NF-kappaB signaling in response to TLR-4, TNF-R and IL-1R stimulation, with a special focus on the similarities and dissimilarities among these pathways. [less ▲]

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See detailLipopolysaccharide-mediated interferon regulatory factor activation involves TBK1-IKK epsilon-dependent lys(63)-linked polyubiquitination and phosphorylation of TANK/I-TRAF
GATOT, Jean-Stéphane ULg; Gioia, Romain ULg; Chau, Tieu-Lan ULg et al

in Journal of Biological Chemistry (2007), 282(43), 31131-31146

Type I interferon gene induction relies on IKK-related kinase TBK1 and IKK epsilon-mediated phosphorylations of IRF3/7 through the Toll-like receptor-dependent signaling pathways. The scaffold proteins ... [more ▼]

Type I interferon gene induction relies on IKK-related kinase TBK1 and IKK epsilon-mediated phosphorylations of IRF3/7 through the Toll-like receptor-dependent signaling pathways. The scaffold proteins that assemble these kinase complexes are poorly characterized. We show here that TANK/ITRAF is required for the TBK1- and IKK epsilon-mediated IRF3/7 phosphorylations through some Toll-like receptor-dependent pathways and is part of a TRAF3-containing complex. Moreover, TANK is dispensable for the early phase of double-stranded RNA-mediated IRF3 phosphorylation. Interestingly, TANK is heavily phosphorylated by TBK1-IKK epsilon upon lipopolysaccharide stimulation and is also subject to lipopolysaccharide- and TBK1-IKK epsilon-mediated Lys(63)-linked polyubiquitination, a mechanism that does not require TBK1-IKK epsilon kinase activity. Thus, we have identified TANK as a scaffold protein that assembles some but not all IRF3/7-phosphorylating TBK1-IKK epsilon complexes and demonstrated that these kinases possess two functions, namely the phosphorylation of both IRF3/7 and TANK as well as the recruitment of an E3 ligase for Lys63-linked polyubiquitination of their scaffold protein, TANK. [less ▲]

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