S Phase Dependence and Involvement of Nf-Kappab Activating Kinase to Nf-Kappab Activation by Camptothecin

in Biochemical Pharmacology (2001), 62(5), 603-16

Camptothecin (CPT) and derivatives are topoisomerase I poisons currently used as anticancer drugs. Their cytotoxicity is maximal for cells in S phase. Using asynchronous and S phase-synchronized HeLa ... [more ▼]

Camptothecin (CPT) and derivatives are topoisomerase I poisons currently used as anticancer drugs. Their cytotoxicity is maximal for cells in S phase. Using asynchronous and S phase-synchronized HeLa cells, we showed that both the nuclear factor-kappaB (NF-kappaB) activation and its transcriptional activity, induced by CPT treatment, are enhanced in S phase cells. After CPT treatment, NF-kappaB activation reached a maximum within 2-3 hr and was still detectable after 24 hr. The nature of the complex evolved with time, forming mostly p50/p65 after 2 hr to almost exclusively p52 after 24 hr. In HeLa cells, the different steps of the induction were readily observable in S phase synchronized cells, whereas they were barely noticeable in a randomly growing cell population. The signal progressed through the activation of the IKK complex, the phosphorylation of IkappaBalpha, and the degradation of phosphorylated-IkappaBalpha and -IkappaBbeta. The stable expression of wild-type HA-tagged-IkappaBalpha or mutated HA-tagged-IkappaBalpha (S32,36A) allowed us to confirm the essential role of Ser32 and Ser36. NF-kappaB-activating kinase (NIK) could play a role upstream of the IKK complex, as the transient expression of a kinase inactive mutant NIK(K429,430A) abolished the activation of NF-kappaB by CPT. A kinase inactive mutant of mitogen-activated protein/ERK kinase kinase 1 (MEKK1), another kinase susceptible of acting upstream of the signalsome, did not. Cytotoxicity studies with clonal populations expressing different amounts of wild-type or mutated IkappaBalpha revealed that the overexpression of wild-type IkappaBa in large amount increases the sensitivity of HeLa cells to CPT more efficiently than a lower level of expression of non-phosphorylable IkappaBalpha. [less ▲]

S'auto-former aux TIC

Poster (2009, June)

Poster présentant deux dispositifs de formation visant la maitrise des TIC et la méthodologie (didactique des TIC) qui les sous-tendent.

S’engager dans la Jeunesse étudiante catholique dans les années quarante

in Hudon, Raymond (Ed.) Jeunesses et politique - tome II Mouvements et engagements depuis les années trente (1994)

S'engager dans la lecture : un investissement au service des compétences.

in Actes du 3e Congrès des chercheurs en éducation (2004)

S'engager en secret : retour sur l'Album zutique

Conference given outside the academic context (2010)

S’investir en didactique

in Denooz, Joseph; Dortu, Véronique; Steinmetz, Rudy (Eds.) Hommage à Pierre Somville (2007)

Depuis une vingtaine d’années, la didactique et plus spécifiquement les didactiques disciplinaires se développent beaucoup et participent de plus en plus à la formation des futurs enseignants du ... [more ▼]

Depuis une vingtaine d’années, la didactique et plus spécifiquement les didactiques disciplinaires se développent beaucoup et participent de plus en plus à la formation des futurs enseignants du secondaire et aux recherches en sciences de l’éducation. Face à ce nouveau contexte dans lequel s’inscrit pleinement l’Université de Liège, il est apparu intéressant – dans le cadre d’un ouvrage d’hommage à un Professeur qui s’est lui-même beaucoup impliqué dans le développement de la didactique de trois disciplines (la philosophie, l’histoire de l’art, le latin et le grec) – de nous interroger sur ce nouveau champ scientifique d’investigation qui est peu connu hors des responsables de l’AESS (Agrégation de l’enseignement du degré supérieur). Qu’est-ce que la didactique ? Quels sont ses fondements et ses concepts centraux ? Quel rôle joue-t-elle dans la formation des enseignants ? Quels sont ses défis et perspectives ? [less ▲]

S'ouvrir aux langues et aux cultures grâce à l'éveil aux langues

Book published by Université de Liège, Service de pédagogie expérimentale (2003)

S-, N- and O-[11C]methylations of a Nor precursor adsorbed on Al2O3/KF.

in Journal of Labelled Compounds & Radiopharmaceuticals (1995), 37

S-acetyl-glutathione selectively induces apoptosis in human lymphoma cells through a GSH-independent mechanism

in International Journal of Oncology (2002), 20(1), 69-75

Reduced apoptosis is associated to cancer development. Agents able to restore the programmed cell death responsiveness of cancer cells are foreseen as potential effective cancer therapies. In this study ... [more ▼]

Reduced apoptosis is associated to cancer development. Agents able to restore the programmed cell death responsiveness of cancer cells are foreseen as potential effective cancer therapies. In this study, we report that a glutathione-S-derivative, S-acetyl-glutathione (Sag), induces significant apoptosis in three human lymphoma cell lines, including Daudi, Raji and Jurkat cells while it had no or little effect on either Hut-78 lymphoma cells or the normal BT lymphocytes. We used Annexin-V FACS analysis and DNA laddering to demonstrate that Sag activated apoptosis in the three sensitive cell lines in a dose- and time-dependent-fashion. Using mercury orange staining and FACS analysis, we showed that Sag generated an intracellular GSH depletion in Daudi, Raji and Jurkat cells but not in Hut-78 or the normal BT cells. These data provide direct evidence that Sag specifically activates programmed cell death in lymphoma cells through, at least in part, a depletion of intracellular GSH rather than an increase, as previously suggested. Because of its selective effect on cancer cells, Sag appears as a promising new lymphoma cell apoptosis inducer with potential clinical value for lymphoma patients. [less ▲]

S-wave velocity measurements applied to the seismic microzonation of Basel, Upper Rhine Graben

in Geophysical Journal International (2007), 170

An extensive S-wave velocity survey had been carried out in the frame of a recent seismic microzonation study of Basel and the border areas between Switzerland, France and Germany. The aim was to better ... [more ▼]

An extensive S-wave velocity survey had been carried out in the frame of a recent seismic microzonation study of Basel and the border areas between Switzerland, France and Germany. The aim was to better constrain the seismic amplification potential of the surface layers. The survey included single station (H/V spectral ratios) and ambient vibration array measurements carried out by the Swiss team, aswell as active S-wave velocity measurements performed by the German and French partners. This paper is focused on the application of the array technique, which consists in recording ambient vibrations with a number of seismological stations. Several practical aspects related to the field measurements are outlined. The signal processing aims to determine the dispersion curves of surface waves contained in the ambient vibrations. The inversion of the dispersion curve provides a 1-D S-wave velocity model for the investigated site down to a depth related to the size of the array. Since the size of arrays is theoretically not limited, arrays are known to be well adapted for investigations in deep sediment basins, such as the Upper Rhine Graben including the area of the city of Basel. In this region, 27 array measurements with varying station configurations have been carried out to determine the S-wave velocity properties of the geological layers down to a depth of 100–250 m. For eight sites, the outputs of the array measurements have been compared with the results of the other investigations using active sources, the spectral analysis of surface waves (SASW) and S-wave reflection seismics. Borehole information available for a few sites could be used to calibrate the geophysical measurements. By this comparison, the advantages and disadvantages of the array method and the other techniques are outlined with regard to the effectiveness of the methods and the required investigation depth. The dispersion curves measured with the arrays and the SASW technique were also combined and inverted simultaneously to use the advantages of both methods. Finally, the paper outlines and discusses the contribution of the S-wave velocity survey to the new seismic microzonation of the Basel region. In this regard one major outcome of the survey is the quantification of vertical and lateral changes of the S-wave velocity, due to changing lithology or changing compaction and degree of weathering of the layers. [less ▲]