Effect of 5-azacytidine and galectin-1 on growth and differentiation of the human b lymphoma cell line bl36

BACKGROUND: 5-AzaCytidine (AzaC) is a DNA demethylating drugs that has been shown to inhibit cell growth and to induce apoptosis in certain cancer cells. Induced expression of the galectin1 (Gal1) protein, a galactoside-binding protein distributed widely in immune cells, has been described in cultured hepatoma-derived cells treated with AzaC and this event may have a role in the effect of the drug. According to this hypothesis, we investigated the effect of AzaC and Gal1 on human lymphoid B cells phenotype. METHODS: The effect of AzaC and Gal1 on cell growth and phenotype was determined on the Burkitt lymphoma cell line BL36. An immunocytochemical analysis for detection of Gal1 protein expression was performed in AzaC-treated cells. To investigate the direct effects of Gal1, recombinant Gal1 was added to cells. RESULTS: Treatment of lymphoid B cells with AzaC results in: i) a decrease in cell growth with an arrest of the cell cycle at G0/G1 phase, ii) phenotypic changes consistent with a differentiated phenotype, and iii) the expression of p16, a tumor-suppressor gene whose expression was dependent of its promoter demethylation, and of Gal1. A targeting of Gal 1 to the plasma membrane follows its cytosolic expression. To determine which of the effects of AzaC might be secondary to the induction of Gal1, recombinant Gal1 was added to BL36 cells. Treated cells displayed growth inhibition and phenotypic changes consistent with a commitment toward differentiation. CONCLUSIONS: Altered cell growth and expression of the cell surface plasma cell antigen, CD138 are detectable in BL36 cells treated by AzaC as well as by Gal1. It seems that AzaC-induced Gal1 expression and consequent binding of Gal1 on its cell membrane receptor may be, in part, involved in AzaC-induced plasmacytic differentiation

Etude protéomique de cellules T Jurkat après traitement par de la Galectine-1 recombinante

PARIS7-Bibliothèque centrale (751132105) / SudocSudocFranceF

COMPARISON OF THREE SOFTWARE PACKAGES FOR IDENTIFICATION OF MCF 7 MEMBRANE PROTEINS EXTRACTED WITH TRIFLUOROETHANOL.

The discovery of new markers or therapeutic targets for cancer implies the exploration of sub-proteomes to have access to proteins which couldn't be visible by total proteome exploration. The membrane compartment is currently one of the mos

Thiophilic adsorption revisited☆

International audienceSpecific and efficient selection of serum immunoglobulins, but not other proteins, on T-gel remains difficult. T-gel capacity was determined for different activation conditions and serum loadings. Mass spectrometry analysis was used to identify the proteins found in the flow-through and in the eluted fractions. Alpha-2-macroglobulin and albumin were the major contaminants of the eluates. The influence of the competition between immunoglobulins and the other serum proteins on the adsorption was also studied. Using a serum depleted in immunoglobulins (flow-through of a first chromatography on T-gel), many serum proteins were retained on the T-gel, including albumin. We conclude that T-gel selectivity is less than absolute and may reflect for a large part the experimental conditions of the adsorption

Analyse protéomique des protéines impliquées dans le phénotype rénal en hypertension rénovasculaire

L'hypertension rénovasculaire est caractérisée par une sténose de l'artère rénale et des taux plasmatiques élevés de rénine, du fait du recrutement des cellules productrices de rénine le long de l'artériole afférente. Cette augmentation du nombre de cellules myoépithélioïdes est due principalement à la différenciation des cellules musculaires lisses préexistantes qui acquièrent un phénotype sécrétoire. Pour comprendre les mécanismes moléculaires impliqués dans ce recrutement, nous avons utilisé le modèle d'hypertension rénovasculaire 1 clip-2 reins, établi chez le rat Lewis. Les artérioles rénales ont été isolées par une suspension magnétique de fer. L'analyse protéomique différentielle a été effectuée par électrophorèse bi-dimensionnelle et l'identification des protéines par spectrométrie de masse. La protéine la plus surprenante identifiée par spectrométrie de masse est la troponine T qui est sous-exprimée dans le rein hypoperfusé. Les expériences en microscopie confocale ont montré que la troponine T n'était exprimée que dans les cellules type musculaire lisse dans le rein et absente des cellules myoépithélioïdes

Usefulness of autoantigens depletion to detect autoantibody signatures by multiple affinity protein profiling

International audiencePatients with cancer produce specific autoantibodies against protein antigens present in limited amount among a large background of immunoglobulins (Igs), nonrelevant as biomarkers, including natural antibodies. Multiple affinity protein profiling (MAPPing) that combines 2-D immunoaffinity chromatography, enzymatic digestion of the isolated proteins, and identification by MS/MS, may facilitate the identification of these so far unknown patient antibodies. The first immunoaffinity chromatography is crucial, as it is used for selectively removing proteins (autoantigens) recognized by natural antibodies. Application of this depletion step to colon cancer cell proteins is specifically described along with the identification of the natural autoantigens, as well as the coupling of this depletion step with the next steps. By enabling to separate antibody-binding proteins recognized by either natural autoantibodies or patient-specific antibodies this approach may contribute significantly towards the definition of autoantibody signatures