References of "Dejardin, Emmanuel"
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See detailEgr family members regulate nonlymphoid expression of Fas ligand, TRAIL, and tumor necrosis factor during immune responses.
Droin, Nathalie; Pinkoski, Mike; Dejardin, Emmanuel ULg et al

in Molecular & Cellular Biology (2003), 23(21), 7638-7647

The Fas ligand (FasL)/Fas pathway is crucial for homeostasis of the immune system and peripheral tolerance. Peripheral lymphocyte deletion involves FasL/Fas in at least two ways: coexpression of both Fas ... [more ▼]

The Fas ligand (FasL)/Fas pathway is crucial for homeostasis of the immune system and peripheral tolerance. Peripheral lymphocyte deletion involves FasL/Fas in at least two ways: coexpression of both Fas and its ligand on T cells, leading to activation-induced cell death, and expression of FasL by nonlymphoid cells, such as intestinal epithelial cells (IEC), that kill Fas-positive T cells. We demonstrate here that superantigen Staphylococcus enterotoxin B (SEB) induced a dramatic upregulation of FasL, TRAIL, and TNF mRNA expression and function in IEC from BALB/c and C57BL/6 mice. Using adoptive transfer in which CD4(+) T cells from OT-2 T-cell receptor transgenic mice were transferred into recipients, we observed an induction in IEC of FasL, TRAIL, and TNF mRNA after administration of antigen. Specific Egr-binding sites have been identified in the 5' promoter region of the FasL gene, and Egr-1, Egr-2, and Egr-3 mRNA in IEC from mice treated with SEB and from transgenic OT-2 mice after administration of antigen was upregulated. Overexpression of Egr-2 and Egr-3 induced endogenous ligand upregulation that was inhibited by overexpression of Egr-specific inhibitor Nab1. These results support a role for Egr family members in nonlymphoid expression of FasL, TRAIL, and TNF. [less ▲]

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See detailThe lymphotoxin-beta receptor induces different patterns of gene expression via two NF-kappaB pathways.
Dejardin, Emmanuel ULg; Droin, Nathalie; Delhase, Mireille et al

in Immunity (2002), 17

The lymphotoxin-beta receptor (LTbetaR) plays critical roles in inflammation and lymphoid organogenesis through activation of NF-kappaB. In addition to activation of the classical NF-kappaB, ligation of ... [more ▼]

The lymphotoxin-beta receptor (LTbetaR) plays critical roles in inflammation and lymphoid organogenesis through activation of NF-kappaB. In addition to activation of the classical NF-kappaB, ligation of this receptor induces the processing of the cytosolic NF-kappaB2/p100 precursor to yield the mature p52 subunit, followed by translocation of p52 to the nucleus. This activation of NF-kappaB2 requires NIK and IKKalpha, while NEMO/IKKgamma is dispensable for p100 processing. IKKbeta-dependent activation of canonical NF-kappaB is required for the expression but not processing of p100 and for the expression of proinflammatory molecules including VCAM-1, MIP-1beta, and MIP-2 in response to LTbetaR ligation. In contrast, IKKalpha controls the induction by LTbetaR ligation of chemokines and cytokines involved in lymphoid organogenesis, including SLC, BLC, ELC, SDF1, and BAFF. [less ▲]

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See detailThe lymphotoxin-β receptor induces different patterns of gene expression via two NF-κB pathways
Dejardin, Emmanuel ULg; Droin, Nathalie; Delhase, Mireille et al

Conference (2002)

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See detailIKKα and IKKβ have different roles in LTβR-mediated NF-κB activation.
Dejardin, Emmanuel ULg; Haas, Elvira; Ware, Carl et al

Conference (2001, November 09)

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See detailInhibition of the Nf-Kappa B Transcription Factor Increases Bax Expression in Cancer Cell Lines
Bentires-Alj, M.; Dejardin, Emmanuel ULg; Viatour, Patrick ULg et al

in Oncogene (2001), 20(22), 2805-13

The NF-kappa B transcription factor has been shown to inhibit apoptosis in several experimental systems. We therefore investigated whether the expression of the Bax proapoptotic protein could be ... [more ▼]

The NF-kappa B transcription factor has been shown to inhibit apoptosis in several experimental systems. We therefore investigated whether the expression of the Bax proapoptotic protein could be influenced by NF-kappa B activity. Increased Bax protein expression was detected in HCT116, OVCAR-3 and MCF7 cells stably expressing a mutated unresponsive I kappa B-alpha inhibitory protein that blocks NF-kappa B activity. Northern blots showed that bax mRNA expression was increased as a consequence of mutated I kappa B-alpha expression in HCT116 cells. A careful examination of the human bax gene promoter sequence showed three putative binding sites for NF-kappa B, and the kappa B2 site at position -687 could indeed bind NF-kappa B complexes in vitro. Transient transfection of a bax promoter luciferase construct in HCT116 cells showed that NF-kappa B proteins could partially inhibit the transactivation of the bax promoter by p53. Mutations or deletions of the kappa B sites, including kappa B2, indicated that this NF-kappa B-dependent inhibitory effect did not require NF-kappa B DNA-binding, and was thus an indirect effect. However, cotransfection of expression vectors for several known cofactors failed to identify a competition between p53 and NF-kappa B for a transcription coactivator. Our findings thus demonstrate for the first time that NF-kappa B regulates, through an indirect pathway, the bax gene expression. [less ▲]

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See detailRegulation of Nf-Kappab Activity by I Kappab-Related Proteins in Adenocarcinoma Cells
Dejardin, Emmanuel ULg; Deregowski, Valérie; Chapelier, Muriel et al

in Oncogene (1999), 18(16), 2567-77

Constitutive NF-kappaB activity varies widely among cancer cell lines. In this report, we studied the expression and the role of different I kappaB inhibitors in adenocarcinoma cell lines. High ... [more ▼]

Constitutive NF-kappaB activity varies widely among cancer cell lines. In this report, we studied the expression and the role of different I kappaB inhibitors in adenocarcinoma cell lines. High constitutive NF-kappaB activity and low I kappaB-alpha expression was found in a number of these cell lines. Moreover, some of these cells showed a high p100 expression, responsible for the cytoplasmic sequestration of most of p65 complexes. Treatment of these cells with TNF-alpha or other NF-kappaB activating agents induced only weakly nuclear NF-kappaB activity without significant p100 processing and led to a very weak transcription of NF-kappaB-dependent reporter gene. Induction of NF-kappaB activity can be restored by expression of the Tax protein or by treatment with antisense p100 oligonucleotides. In MCF7 A/Z cells stably transfected with a p100 expression vector, p65 complexes were sequestered in the cytoplasm by p100. These cells showed a reduced nuclear NF-kappaB induction and NF-kappaB-dependent gene transcription following TNF-alpha stimulation. As a consequence of a competition between I kappaB-alpha and p100, cells expressing high levels of p100 respond poorly to NF-kappaB activating stimuli as TNF-alpha. [less ▲]

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See detailRegulation of major histocompatibility complex class I expression by NF-kB-related proteins in breast cancer cells
Dejardin, Emmanuel ULg; Deregowski, Valérie; GREIMERS, Roland ULg et al

in Oncogene (1998)

Downregulation of MHC Class I antigens has been observed in many cancers and usually results from a decreased gene transcription. A reporter CAT gene dependent on the MHC Class I kB site or on a longer ... [more ▼]

Downregulation of MHC Class I antigens has been observed in many cancers and usually results from a decreased gene transcription. A reporter CAT gene dependent on the MHC Class I kB site or on a longer promoter is transactivated by NF-kB complexes contain- ing p65 or RelB. p100 as well as IkB-a are potent inhibitors of this transcription and p100 sequesters RelB and p65 complexes in the cytoplasm of breast cancer cells. However, although p100 is highly expressed in a number of breast cancer cell lines, MHC Class I antigen expression was observed on all the cell lines we analysed and could be further induced by stimulation with the cytokines IFN-g or TNF-a. Stable transfection of a unresponsive mutated IkB-a Ser 32-36 expression vector showed that TNF-a induced MHC Cl I expression in an NF-kB-dependent way while IFN-g did it independently of any NF-kB activation. [less ▲]

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See detailInterleukin-1 Beta Induces Nuclear Factor Kappa B in Epithelial Cells Independently of the Production of Reactive Oxygen Intermediates
Bonizzi, Giuseppina; Dejardin, Emmanuel ULg; Piret, Bernard et al

in European Journal of Biochemistry (1996), 242(3), 544-9

A large body of work has been devoted to tumor necrosis factor alpha or interleukin-1 beta (IL-1 beta) signaling leading to the activation of the transcription factor nuclear factor-kappa B (NF-kappa B ... [more ▼]

A large body of work has been devoted to tumor necrosis factor alpha or interleukin-1 beta (IL-1 beta) signaling leading to the activation of the transcription factor nuclear factor-kappa B (NF-kappa B) in various cell types. Several studies have indicated that NF-kappa B activation depends strictly on the production of reactive oxygen intermediates. In this report, we first demonstrated that IL-1 beta is a potent activator of NF-kappa B in various epithelial transformed cell lines (OVCAR-3, SKOV-3, MCF7 A/Z). In these cells, IL-1 beta rapidly induces NF-kappa B through a complete degradation of I kappa B-alpha, while H2O2 activates NF-kappa B with slower kinetics through a partial degradation of I kappa B-alpha, p100 and p105. We showed that IL-1 beta-mediated induction of NF-kappa B in OVCAR-3 and in other epithelial cell lines does not proceed through the production of reactive oxygen intermediates, while the same cytokine activates NF-kappa B in lymphoid cells through the intracellular generation of H2O2. Our study demonstrated that several signaling pathways lead to the activation of NF-kappa B, following IL-1 beta treatment in different cell types. [less ▲]

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See detailHighly-Expressed P100/P52 (Nfkb2) Sequesters Other Nf-Kappa B-Related Proteins in the Cytoplasm of Human Breast Cancer Cells
Dejardin, Emmanuel ULg; Bonizzi, Giuseppina; Bellahcene, Akeila ULg et al

in Oncogene (1995), 11(9), 1835-41

Several observations have suggested that NF-kappa B transcription factors could be involved in carcinogenesis. To investigate the possibility that members of the NF-kappa B family participate in the ... [more ▼]

Several observations have suggested that NF-kappa B transcription factors could be involved in carcinogenesis. To investigate the possibility that members of the NF-kappa B family participate in the molecular control of the transformed phenotype, we examined the expression of these proteins in human breast cancer cell lines as well as in primary tumors. Western Immunoblots demonstrated high expression of the p52 precursor p100 (NFKB2) in several breast cancer cell lines while human mammary epithelial cells express this protein only faintly. Eighteen primary breast tumors out of 24 displayed significant expression of the p100/p52 protein. In MDA-MB-435 cells, overexpressed p100 and p52 are predominantly cytoplasmic and coimmunoprecipitation experiments demonstrated that p100 sequesters the heterodimer p50/p65 in the cytoplasm. We demonstrate that most p65 protein is complexed with p100 in these cells while it is complexed predominantly with I kappa B-alpha in cell lines expressing less p100. Our data strengthen the hypothesis that NF-kappa B could be involved in carcinogenesis and suggest that the p100/p52 NF-kappa B subunit could play a role in the development of human breast cancers, possibly by sequestering other NF-kappa B-related proteins in the cytoplasm. [less ▲]

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See detailThe Nf-Kappa B Transcription Factor and Cancer: High Expression of Nf-Kappa B- and I Kappa B-Related Proteins in Tumor Cell Lines
Bours, Vincent ULg; Dejardin, Emmanuel ULg; Goujon-Letawe, F. et al

in Biochemical Pharmacology (1994), 47(1), 145-9

NF-kappa B is a pleiotropic transcription factor which controls the expression of many genes and viruses. To date, there is good evidence, but no definitive proof, for its role in tumor formation and ... [more ▼]

NF-kappa B is a pleiotropic transcription factor which controls the expression of many genes and viruses. To date, there is good evidence, but no definitive proof, for its role in tumor formation and development of metastasis. To investigate the possibility that members of the NF-kappa B family could participate in the molecular control of the transformed and invasive phenotype, we examined the expression of these proteins in a variety of human tumor cell lines. The expression of p50, p65, p52 and I kappa B was quantified at the protein level using western immunoblot and mobility shift assay and at the RNA level by northern blot. We observed high expression of the NF-kappa B inhibitor I kappa B in the ovarian carcinoma cell line OVCAR-3 together with constitutive nuclear NF-kappa B activity. We also studied the colon carcinoma cell line HT-29 and its metastatic counterpart HTM-29 and we observed specific expression of the p52 NF-kappa B-related protein in the metastatic cells. Our data confirm that NF-kappa B could be involved in the genesis of a variety of cancers including solid tumors and provide us with interesting models to explore the exact role of these transcription factors in cancer. [less ▲]

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See detailHuman RelB (I-Rel) functions as a kappa B site-dependent transactivating member of the family of Rel-related proteins.
Bours, Vincent ULg; Azarenko, V.; Dejardin, Emmanuel ULg et al

in Oncogene (1994), 9(6), 1699-702

RelB belongs to the family of Rel-related proteins, dimers of which determine NF-kappa B activity. The murine RelB protein has been reported to be a dimerizing partner in kappa B-binding complexes which ... [more ▼]

RelB belongs to the family of Rel-related proteins, dimers of which determine NF-kappa B activity. The murine RelB protein has been reported to be a dimerizing partner in kappa B-binding complexes which are capable of transactivation. On the other hand, the I-Rel protein, the presumed human homolog of RelB, was proposed to be an inhibitor whose presence in dimeric complexes interfered with their kappa B binding and therefore interfered also with transactivation. We demonstrate that human RelB (I-Rel) forms with p50 and p52 (p50B) kappa B-binding heterodimeric complexes which potently transactivate kappa B-dependent constructs in transfection studies. It is concluded that human RelB (I-Rel) and murine RelB can both function as transactivators and that no significant species-specific differences exist. [less ▲]

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