References of "Bours, Vincent"
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See detailNF-κB transcription factor induces drug resistance through MDR1 expression in cancer cells
Bentires-Alj, Mohamed; Barbu, Véronique; Fillet, Marianne ULg et al

in Oncogene (2003), 22

The ubiquitous NF-kappaB transcription factor has been reported to inhibit apoptosis and to induce drug resistance in cancer cells. Drug resistance is the major reason for cancer therapy failure and ... [more ▼]

The ubiquitous NF-kappaB transcription factor has been reported to inhibit apoptosis and to induce drug resistance in cancer cells. Drug resistance is the major reason for cancer therapy failure and neoplastic cells often develop multiple mechanisms of drug resistance during tumor progression. We observed that NF-kappaB or P-glycoprotein inhibition in the HCT15 colon cancer cells led to increased apoptotic cell death in response to daunomycin treatment. Interestingly, NF-kappaB inhibition through transfection of a plasmid coding for a mutated IkappaB-alpha inhibitor increased daunomycin cell uptake. Indeed, the inhibition of NF-kappaB reduced mdr1 mRNA and P-glycoprotein expression in HCT15 cells. We identified a consensus NF-kappaB binding site in the first intron of the human mdr1 gene and demonstrated that NF-kappaB complexes could bind with this intronic site. Moreover, NF-kappaB transactivates an mdr1 promoter luciferase construct. Our data thus demonstrate a role for NF-kappaB in the regulation of the mdr1 gene expression in cancer cells and in drug resistance. [less ▲]

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See detailClonal chromosome aberrations in Philadelphia-negative cells from chronic myelocytic leukemia patients treated with imatinib mesylate: report of two cases.
Herens, Christian ULg; Baron, Frédéric ULg; Croisiau, Christiane et al

in Cancer Genetics & Cytogenetics (2003), 147(1), 78-80

Imatinib mesylate (tested as STI571), an abl kinase inhibitor, induces sustained, complete hematologic and cytogenetic responses in chronic myelocytic leukemia (CML) patients; however, emergence of clonal ... [more ▼]

Imatinib mesylate (tested as STI571), an abl kinase inhibitor, induces sustained, complete hematologic and cytogenetic responses in chronic myelocytic leukemia (CML) patients; however, emergence of clonal chromosomal aberrations in Philadelphia-negative (Ph-) cells during treatment has been reported. We describe two CML patients in chronic phase who presented with complete cytogenetic responses during imatinib mesylate therapy but developed new clonal chromosomal rearrangements in Ph- cells. The first patient presented with a duplication of chromosome 1, dup(1)(q21q42), and the second showed two new clonal aberrations consisting of inv(1)(q12q32) and del(7)(q22) in the same clone. [less ▲]

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See detailSynergistic activation of human immunodeficiency virus type 1 promoter activity by NF-kappa B and inhibitors of deacetylases: Potential perspectives for the development of therapeutic strategies
Quivy, Vincent; Adam, Emmanuelle; Collette, Yves et al

in Journal of Virology (2002), 76(21), 11091-11103

The transcription factor NF-kappaB plays a central role in the human immunodeficiency virus type 1 (HIV-1) activation pathway. HIV-1 transcription is also regulated by protein acetylation, since treatment ... [more ▼]

The transcription factor NF-kappaB plays a central role in the human immunodeficiency virus type 1 (HIV-1) activation pathway. HIV-1 transcription is also regulated by protein acetylation, since treatment with deacetylase inhibitors such as trichostatin A (TSA) or sodium butyrate (NaBut) markedly induces HIV-1 transcriptional activity of the long terminal repeat (LTR) promoter. Here, we demonstrate that TSA (NaBut) synergized with both ectopically expressed p50/p65 and tumor necrosis factor alpha/SF2 (TNF)-induced NF-kappaB to activate the LTR. This was confirmed for LTRs from subtypes A through G of the HIV-1 major group, with a positive correlation between the number Of kappaB sites present in the LTRs and the amplitude of the TNF-TSA synergism. Mechanistically, TSA (NaBut) delayed the cytoplasmic recovery of the inhibitory protein IkappaBalpha. This coincided with a prolonged intranuclear presence and DNA binding activity of NF-kappaB. The physiological relevance of the TNF-TSA (NaBut) synergism was shown on HIV-1 replication in both acutely and latently HIV-infected cell lines. Therefore, our results open new therapeutic strategies aimed at decreasing or eliminating the pool of latently HIV-infected reservoirs by forcing viral expression. [less ▲]

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See detailComment je traite.... Le cancer avance du pancreas par une approche innovante dirigee contre les nouvelles cibles
Polus, Marc ULg; Bours, Vincent ULg; Jerusalem, Guy ULg et al

in Revue Médicale de Liège (2002), 57(7), 428-32

A better knowledge of fundamental mechanisms of carcinogenesis allows the development of novel therapeutic tools specifically targeting the cancer cell. Our understanding of cellular and molecular ... [more ▼]

A better knowledge of fundamental mechanisms of carcinogenesis allows the development of novel therapeutic tools specifically targeting the cancer cell. Our understanding of cellular and molecular mechanisms controlling cellular cycle and cell survival is an important step for new anti-cancer treatments. This review will focus on new therapeutic's strategies in advanced pancreatic cancer. [less ▲]

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See detailConstitutive nuclear factor-kappa B activity preserves homeostasis of quiescent mature lymphocytes and granulocytes by controlling the expression of distinct Bcl-2 family proteins
Bureau, Fabrice ULg; Vanderplasschen, Alain ULg; Jaspar, Fabrice ULg et al

in Blood (2002), 99(10), 3683-3691

Constitutive nuclear factor kappaB (NFkappaB) activity protects quiescent mature Immune cells from spontaneous apoptosis. Here, we examined whether NF-kappaB exerts its antiapoptotic function in these ... [more ▼]

Constitutive nuclear factor kappaB (NFkappaB) activity protects quiescent mature Immune cells from spontaneous apoptosis. Here, we examined whether NF-kappaB exerts its antiapoptotic function in these cells through the control of Bcl-2 family proteins. Specific pharmacologic inhibitors of NF-kappaB were used to achieve total NF-kappaB inactivation In quiescent human blood lymphocytes, granulocytes, and monocytes. NF-kappaB inhibition induced drastic lymphocyte and granulocyte apoptosis, but only moderate monocyte apoptosis. T- and B-cell apoptosis was slow and associated with a gradual down-regulation of the prosurvival Bcl-2 family proteins Bcl-X-L and BcI-2, respectively. By contrast, granulocyte apoptosis was fast and accompanied by a rapid cellular accumulation of Bcl-x(s), the proapoptotic Bcl-x isoform that is generated from alternative splicing of the bcl-x pre-mRNA. Finally, antisense bci-x(L) and bcl-2 knockdown in T and B cells, respectively, and induction of Bcl-xs expression in granulocytes through antisense oligonucleotide-mediated redirection of bcl-x pre-mRNA splicing were sufficient to induce significant apoptosis in these cells. Taken together, these results reveal that basal NF-kappaB activity preserves homeostasis of quiescent mature lymphocytes and granulocytes through regulation of distinct members of the Bcl-2 family. This study sheds light on the constitutive mechanisms by which NF-kappaB maintains defense integrity. (C) 2002 by The American Society of Hematology. [less ▲]

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See detailLeukemic target susceptibility to natural killer cytotoxicity: relationship with BCR-ABL expression.
Baron, Frédéric ULg; Turhan, Ali G; Giron-Michel, Julien et al

in Blood (2002), 99(6), 2107-13

Chronic myeloid leukemia is a clonal myeloproliferative expansion of transformed primitive hematopoietic progenitor cells characterized by high-level expression of BCR-ABL chimeric gene, which induces ... [more ▼]

Chronic myeloid leukemia is a clonal myeloproliferative expansion of transformed primitive hematopoietic progenitor cells characterized by high-level expression of BCR-ABL chimeric gene, which induces growth factor independence. However, the influence of BCR-ABL expression on cell-mediated cytotoxicity is poorly understood. In the present study, we asked whether BCR-ABL expression interferes with leukemic target sensitivity to natural killer (NK) cell cytolysis. Our approach was based on the use of 2 BCR-ABL transfectants of the pluripotent hematopoietic cell line UT-7 expressing low (UT-7/E8, UT-7/G6) and high (UT-7/9) levels of BCR-ABL. As effector cells, we used CD56(bright), CD16-, CD2- NK cells differentiated in vitro from CD34 cord blood progenitors. We demonstrated that BCR-ABL transfectants UT-7/9 were lysed by NK cells with a higher efficiency than parental and low UT-7/E8.1 and UT-7/G6 transfectants. This enhanced susceptibility to lysis correlated with an increase in expression of intercellular adhesion molecule 1 (ICAM-1) by target cells. Treatment of UT-7/9 cells by STI571 (a specific inhibitor of the abl kinase) resulted in a decrease in NK susceptibility to lysis and ICAM-1 down-regulation in target cells. Furthermore, the constitutive activation of nuclear factor-kappaB (NF-kappaB) detected in BCR-ABL transfectant UT-7/9, was significantly attenuated when cells were treated by STI571. Interestingly, inhibition of NF-kappaB activation by BAY11-67082 (a specific NF-kappaB inhibitor) resulted in down-regulation of ICAM-1 expression and a subsequent decrease in NK-induced killing of UT-7/9 transfectants. Our results show that oncogenic transformation by BCR-ABL may increase susceptibility of leukemic progenitors to NK cell cytotoxicity by a mechanism involving overexpression of ICAM-1 as a consequence of NF-kappaB activation. [less ▲]

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See detailTNF-alpha protects human primary articular chondrocytes from nitric oxide-induced apoptosis via nuclear factor-kappaB
Relic, Biserka ULg; Bentires-Alj, Mohamed; Ribbens, Clio ULg et al

in Laboratory Investigation : Journal of Technical Methods & Pathology (2002), 82(12), 1661-1672

TNF-alpha plays a key role in rheumatoid arthritis, but its effect on chondrocyte survival is still conflicting. In the present study, we tested how TNF-alpha influences chondrocyte survival in response ... [more ▼]

TNF-alpha plays a key role in rheumatoid arthritis, but its effect on chondrocyte survival is still conflicting. In the present study, we tested how TNF-alpha influences chondrocyte survival in response to nitric oxide (NO)-related apoptotic signals, which are abundant during rheumatoid arthritis. Human primary articular chondrocytes or cartilage explants were pretreated with TNF-alpha for 24 hours and then treated with the proapoptotic NO donor sodium-nitro-prusside (SNP) for an additional 24 hours. TNF-alpha pretreatment markedly protected chondrocytes from SNP-induced cell death. Preincubation of chondrocytes with TNF-alpha inhibited both SNP-induced high-molecular weight DNA fragmentation and annexin V-FITC binding. Of interest, TNF-alpha induced persistent nuclear factor-kappaB (NF-kappaB)-DNA binding activity even in the presence of SNP, mirroring apoptosis protection effects. Both the TNF-alpha antiapoptotic effect and NF-kappaB-DNA binding activity were significantly inhibited by NF-kappaB inhibitors, Bay 11-7085, MG-132, and adenovirus-expressing mutated IkappaB-alpha. Phosphatidylinositol-3 kinase inhibitor LY 294002 also markedly inhibited the antiapoptotic effect of TNF-alpha. In primary chondrocytes, TNF-alpha induced expression of the antiapoptotic protein Cox-2, which persisted in the presence of SNP, and a specific Cox-2 inhibitor significantly blocked the TNF-alpha protective effect. We therefore conclude that TNF-alpha-mediated protection of chondrocytes from NO-induced apoptosis acts through NF-kappaB and requires Cox-2 activity. [less ▲]

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See detailEffects of BM-573, a dual thromboxane A2 receptor antagonist and thromboxane synthase inhibitor, on osteogenic sarcoma cell-induced platelet aggregation
De Leval, X.; David, J. L.; Neven, P. et al

Poster (2001, December)

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See detailEffects of BM-573, a dual thromboxane A(2) receptor antagonist and thromboxane synthase inhibitor, on osteogenic sarcoma cell-induced platelet aggregation
de Leval, X.; David, Jean-Louis ULg; Neven, P. et al

in Blood (2001, November 16), 98(11, Part 2), 43

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See detailImpaired Accumulation of Granulocytes in the Lung During Ozone Adaptation
Fievez, Laurence ULg; Kirschvink, N.; Dogne, S. et al

in Free Radical Biology & Medicine (2001), 31(5), 633-641

Respiratory alterations induced by an acute exposure to ozone (O(3)) paradoxically resolve during multiday exposure. This adaptation is characteristically accompanied by a gradual attenuation of lung ... [more ▼]

Respiratory alterations induced by an acute exposure to ozone (O(3)) paradoxically resolve during multiday exposure. This adaptation is characteristically accompanied by a gradual attenuation of lung neutrophilia. As maintenance of neutrophilia at the site of inflammation is due to cytokine-mediated delayed neutrophil apoptosis, which is associated with reduced levels of Bax, a proapoptotic protein, we sought to determine whether defects in these mechanisms could account for O(3) adaptation. Lung granulocytes obtained at different time points from calves exposed to 0.75 ppm O(3) for 12 h/d for 7 consecutive days neither showed enhancement of survival nor Bax deficiency, when compared to blood granulocytes. To further investigate the effects of an exogenous oxidative stress on neutrophil survival, human granulocytes were treated with hydrogen peroxide alone, or in combination with granulocyte/macrophage colony-stimulating factor, an antiapoptotic cytokine. Both treatments led to rapid apoptosis associated with downregulation of Bcl-x(L) and Bcl-2, two antiapoptotic proteins. This study shows that O(3) adaptation is associated with a failure in the mechanisms leading to accumulation of neutrophils at the site of inflammation, and suggests that this defect is due to direct proapoptotic effects of exogenous oxidative stress on granulocytes [less ▲]

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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 detailGenetic Imbalances in Preleukemic Thymuses
Verlaet, Myriam ULg; Deregowski, Valérie; Denis, Ghislaine et al

in Biochemical and Biophysical Research Communications (2001), 283(1), 12-8

To understand the molecular mechanisms involved in preleukemia, the suppression subtractive hybridization method was used in a murine radiation-induced thymic lymphoma model. Seventeen mRNAs overexpressed ... [more ▼]

To understand the molecular mechanisms involved in preleukemia, the suppression subtractive hybridization method was used in a murine radiation-induced thymic lymphoma model. Seventeen mRNAs overexpressed in preleukemic thymuses were identified: mouse laminin binding protein (p40/37LBP), E25 protein, Rattus norvegicus clone BB.1.4.1, profilin, poly(A) binding protein (PABP), mouse high mobility group protein 1, topoisomerase I, clusterin, proteasome RC1 subunit, rat prostatein C3 and C1 subunits; two ESTs and four unknown genes. The overexpression of PABP, clusterin, profilin, and the p40/37LBP mRNAs was confirmed in preleukemic thymuses and can be related to some cellular events observed during the preleukemic period, i.e., alterations of cell cycle and apoptosis properties. The p40/37LBP and 67-kDa laminin receptor proteins were upregulated during the preleukemic period. The data suggest that additional studies on p40/37LBP and 67-kDa laminin receptor regulation are required to evaluate their potential role in the lymphoma prevention by TNF-alpha and IFN-gamma. [less ▲]

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See detailRat Gap Junction Connexin-30 Inhibits Proliferation of Glioma Cell Lines
Princen, Frederic; Robe, Pierre ULg; Gros, D. et al

in Carcinogenesis (2001), 22(3), 507-13

Connexins, the structural components of gap junctions, control cell growth and differentiation and are believed to belong to a family of tumour suppressor genes. Studies on connexin localization in brain ... [more ▼]

Connexins, the structural components of gap junctions, control cell growth and differentiation and are believed to belong to a family of tumour suppressor genes. Studies on connexin localization in brain showed that several of these proteins were expressed in distinct compartments of the brain in a cell-type specific manner, indicating that different gap junctions play specific roles in the physiology of the mammalian brain. In this report, we first cloned rat connexin-30 cDNA from brain and showed that it was expressed in long-term primary culture of rat astrocytes. In order to examine the potential role of connexin-30 in tumour cell proliferation, we transfected the connexin-30 cDNA into two rat glioma cell lines (9L and C6) which have lost its expression. Transfected clones adequately expressed membrane-bound connexin-30 protein. Connexin-30-expressing clones showed slower growth, lower DNA synthesis and reduced proliferation in soft agar as compared with the parental and control cells. We concluded that connexin-30 may also probably be considered as a tumour suppressor in rat gliomas. [less ▲]

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See detailRadiofrequency ablation of liver tumors: short term evaluation
Detry, Olivier ULg; Detroz, Bernard ULg; Preud'Homme, Laurence ULg et al

in Acta Gastro-Enterologica Belgica (2001, January), 64(1), 11

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See detailOzone adaptation in calves is associated with impaired accumulation of granulocytes in the lung
Fievez, Laurence ULg; Kirschvink, Nathalie; Dogné, S. et al

in Proceedings: Comparative Respiratory Society Meeting (2001)

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See detailConstitutive NF-kappaB activity preserves homeostasis of quiescent mature lymphocytes and granulocytes by controlling the expression of distinct Bcl-2 family proteins
Bureau, Fabrice ULg; Vanderplasschen, Alain ULg; Jaspar, F. et al

in Proceedings: International Symposium: NF-kappaB: Regulation, Gene Expression & Disease (2001)

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See detailRoles of Nuclear Factor-Kappab, P53, and P21/Waf1 in Daunomycin-Induced Cell Cycle Arrest and Apoptosis
Hellin, A. C.; Bentires-Alj, M.; Verlaet, Myriam ULg et al

in Journal of Pharmacology and Experimental Therapeutics (The) (2000), 295(3), 870-8

Daunomycin is a potent inducer of p53 and NF-kappaB transcription factors. It is also able to increase the amount of the p21 cyclin-dependent kinase inhibitor. The human p21 promoter harbors p53 ... [more ▼]

Daunomycin is a potent inducer of p53 and NF-kappaB transcription factors. It is also able to increase the amount of the p21 cyclin-dependent kinase inhibitor. The human p21 promoter harbors p53-responsive elements and an NF-kappaB binding site. [less ▲]

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