BCL2L10 is a predictive factor for resistance to Azacitidine in MDS and AML patients

Azacitidine is the leading compound to treat patients suffering myelodysplastic syndrome (MDS) or AML with less than 30% of blasts, but a majority of patients is primary refractory or rapidly relapses under treatment. These patients have a drastically reduced life expectancy as compared to sensitive patients. Therefore identifying predictive factors for AZA resistance is of great interest to propose alternative therapeutic strategies for non-responsive patients. We generated AZA-resistant myeloid cell line (SKM1-R) that exhibited increased expression of BCL2L10 an anti-apoptotic Bcl-2 family member. Importantly, BCL2L10 knockdown sensitized SKM1-R cells to AZA effect suggesting that increased BCL2L10 expression is linked to AZA resistance in SKM1-R. We next established in 77 MDS patients that resistance to AZA is significantly correlated with the percentage of MDS or AML cells expressing BCL2L10. In addition, we showed that the proportion of BCL2L10 positive bone marrow cells can predict overall survival in MDS or AML patients. We propose a convenient assay in which the percentage of BCL2L10 expressing cells as assessed by flow cytometry is predictive of whether or not a patient will become resistant to AZA. Therefore, systematic determination of BCL2L10 expression could be of great interest in newly diagnosed and AZA-treated MDS patients

Vers de nouveaux inhibiteurs de la transférase bactérienne MraY (Conception et synthèse de bioisostères de pyrophosphate)

Afin de lutter contre l'émergence continue de résistances aux antibiotiques, le développement de nouveaux agents antibactériens et l'identification de nouvelles cibles enzymatiques s'avèrent nécessaires. La transférase bactérienne MraY, impliquée dans la biosynthèse du peptidoglycane, constitue une telle cible. Les objectifs de cette thèse ont été la conception et la synthèse d'analogues de l'UDP-Mur/VAc-pentapeptide, substrat nucléotidique naturel de MraY. La principale modification envisagée a concerné le groupement pyrophosphate, motif clé responsable de la réactivité du substrat. Deux familles de bioisostères ont été ciblées : des analogues de type b-cétophosphonate et de type phosphmoylméthylphosphonate. L'élaboration de ces structures a nécessité la préparation de synthons phosphores et de C-glycosides diversement fonctionnalisés. Le développement de bioisostères de type thiophosphophosphate a aussi été initié afin d'approfondir l'étude du mécanisme d'action de MraY.In order to contain the expansion of bacterial resistance against antibiotics, development of new antibacterial agents and research for new enzymatic targets are required. The bacterial transferase MraY, involved in the peptidoglycan biosynthesis, is such a target. The aim of this work was to design and synthesize analogs of UDP-Mur/VAc-pentapeptide, the natural nucleotidic substrate of MraY. The main modification was directed towards the pyrophosphate group, which is the key moiety responsible for the substrate reactivity. Two bioisosteres families were targeted: b-ketophosphonate analogs and phosphinoylmethylphosphonate analogs. Synthesis of these structures required preparation of phosphorus synthons and C-glycosides variously fonctionalised. Development of thiophosphophosphate bioisosteres was also initiated in order to investigate the MraY mechanism.PARIS-BIUP (751062107) / SudocSudocFranceF

Synthesis of a β-Ketophosphonate Bioisostere of UDP- N -acetylglucosamine

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Lewis acid-catalysed nucleophilic opening of a bicyclic hemiaminal followed by ring contraction: Access to functionalized L-idonojirimycin derivatives

International audienceThe Lewis acid-catalyzed nucleophilic opening of a D-gluco-configured bicyclic hemiaminal has been examined.Several Lewis acids and silylated nucleophiles have been screened allowing the introduction of acetophenone,phosphonate or nitrile at the pseudoanomeric position in satisfactory yields and high 1,2 trans stereoselectivities.Their skeletal rearrangement triggered by the N-benzyl anchimeric assistance provided the corresponding L-idoconfiguredpiperidines displaying various functional groups at C-6 position in good yield

Stereoselective Access to Iminosugar C, C-Glycosides from 6-Azidoketopyranoses

International audienceWe report the synthesis of iminosugar C,C-glycosides starting from 6-azidoketopyranoses. Their Staudinger-azaWittig-mediated cyclization provided bicyclic N,O-acetals, which were stereoselectively opened with AllMgBr to afford β-hydroxyazepanes with a quaternary carbon α to the nitrogen. Their ring contraction via a β-aminoalcohol rearrangement produced the six-membered l-iminosugars with two functional handles at the pseudoanomeric position. Inversion of the free OH at the azepane level furnished the d-iminosugars

A population of thermostable reverse transcriptases evolved from Thermus aquaticus DNA polymerase I by phage display.

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Multi-Stage Mass Spectrometry Analysis of Sugar-Conjugated β-Turn Structures to be Used as Probes in Autoimmune Diseases

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Synthesis and biological evaluation of potential new inhibitors of the bacterial transferase MraY with a β-ketophosphonate structure

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