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Souissi I.,French Institute of Health and Medical Research | Souissi I.,University of Paris 13 | Ladam P.,University of Paris 13 | Ladam P.,CNRS Laboratory of Chemistry, Structures, Biomaterials Properties and Therapeutic Agents | And 10 more authors.
Molecular Cancer | Year: 2012

Background: The Signal Transducer and Activator of Transcription 3 (STAT3) is activated in tumor cells, and STAT3-inhibitors are able to induce the death of those cells. Decoy oligodeoxynucleotides (dODNs), which bind to the DNA Binding Domain (DBD) of STAT3, are efficient inhibitors. However, they also inhibit STAT1, whose activity is essential not only to resistance to pathogens, but also to cell growth inhibition and programmed cell death processes. The aim of this study was to design STAT3-specific dODNs which do not affect STAT1-mediated processes.Results: New dODNs with a hairpin (hpdODNs) were designed. Modifications were introduced, based on the comparison of STAT3- and STAT1-DBD interactions with DNA using 3D structural analyses. The designed hpdODNs were tested for their ability to inhibit STAT3 but not STAT1 by determining: i) cell death in the active STAT3-dependent SW480 colon carcinoma cell line, ii) absence of inhibition of interferon (IFN) γ-dependent cell death, iii) expression of STAT1 targets, and iv) nuclear location of STAT3 and STAT1. One hpdODN was found to efficiently induce the death of SW480 cells without interfering with IFNγ-activated STAT1. This hpdODN was found in a complex with STAT3 but not with STAT1 using an original in-cell pull-down assay; this hpdODN also did not inhibit IFNγ-induced STAT1 phosphorylation, nor did it inhibit the expression of the STAT1-target IRF1. Furthermore, it prevented the nuclear transfer of STAT3 but not that of IFNγ-activated STAT1.Conclusions: Comparative analyses at the atomic level revealed slight differences in STAT3 and STAT1 DBDs' interaction with their DNA target. These were sufficient to design a new discriminating hpdODN that inhibits STAT3 and not STAT1, thereby inducing tumor cell death without interfering with STAT1-dependent processes. Preferential interaction with STAT3 depends on oligodeoxynucleotide sequence modifications but might also result from DNA shape changes, known to modulate protein/DNA interactions. The finding of a STAT3-specific hpdODN establishes the first rational basis for designing STAT3 DBD-specific inhibitors. © 2012 Souissi et al; licensee BioMed Central Ltd.

Drogat N.,CNRS Chemistry of Natural Substances Laboratory | Jauberty L.,CNRS Chemistry of Natural Substances Laboratory | Chaleix V.,CNRS Chemistry of Natural Substances Laboratory | Granet R.,CNRS Chemistry of Natural Substances Laboratory | And 3 more authors.
Materials Letters | Year: 2014

We describe a sensing system that relies upon the formation of specific complexes between uranyl ion and bisphosphonate-capped gold nanoparticles. The ensuing concentration-dependent red-shift of surface plasmon resonance absorption allows the determination of uranyl ion concentration within the 1.5-15 ppm range. © 2014 Elsevier B.V.

Patil N.,University of Liege | Falentin-Daudre C.,University of Liege | Falentin-Daudre C.,CNRS Laboratory of Chemistry, Structures, Biomaterials Properties and Therapeutic Agents | Jerome C.,University of Liege | Detrembleur C.,University of Liege
Polymer Chemistry | Year: 2015

This paper describes the reversible addition-fragmentation chain transfer (RAFT) polymerization of mussel-inspired acetonide-protected dopamine (meth)acrylamide monomers (ADA and ADMA) and its implementation to the synthesis of innovative ambivalent block copolymers. They consist of a hydrophobic poly((meth)acrylamide) block functionalized by catechols and a hydrophilic segment of a poly((meth)acrylate) bearing pendent PEG chains. For the first time, a series of well-defined P(PEGAm-b-ADAn) and P(ADMAn-b-PEGMAm) diblock copolymers across a range of molar masses (13-42 kg mol-1) with low molar mass dispersities (= 1.12 - 1.25) were reported. Post polymerization, trifluoroacetic acid (TFA) treatment yields block copolymers bearing free-catechol units in quantitative yields (>95%) with a slight noticeable hydrolysis of pendent-PEG units (2%-4%). The self-assembly of the amphiphilic block copolymers into spherical micelles was demonstrated by 1H NMR, DLS and TEM imaging techniques. Real-time quartz crystal microbalance with dissipation monitoring (QCM-D) studies revealed that free-catechol groups were necessary for a strong anchoring onto gold and stainless steel surfaces because acetonide-protected and catechol-oxidized block copolymers completely desorbed from the surface in the rinsing step. The ambivalent nature of catechol functionalized block copolymers was studied by bovine serum albumin (BSA) adsorption on polymer modified surfaces, which displayed improved resistance against BSA adsorption, when compared to an unmodified surface. This journal is © The Royal Society of Chemistry 2015.

Bryche J.-F.,CNRS Fundamental Electronics Institute | Bryche J.-F.,French National Center for Scientific Research | Tsigara A.,CNRS Fundamental Electronics Institute | Belier B.,CNRS Fundamental Electronics Institute | And 4 more authors.
Sensors and Actuators, B: Chemical | Year: 2016

We report on an improvement way of the SERS signal of Au triangular nanoprisms for a highly sensitive detection of chemical molecules. This improvement is obtained by a simple addition of a gold reflective layer under Au nanoprisms. Using the same Au triangular nanoprisms obtained by nanosphere lithography, we studied experimentally the thickness effect of this gold underlayer on the SERS intensity of the triangular nanoprisms. We demonstrated that this SERS intensity increased with the thickness of the gold reflective underlayer, and this is due to the increment of the Au underlayer reflectivity. Thus, we showed that the metallic reflective underlayer has an important key for SERS enhancement. Indeed, enhancement factors of 108 were found for the most important thickness of the gold underlayer. © 2016 Elsevier B.V. All rights reserved.

Babouri R.,Charles Gerhardt Institute | Babouri R.,University of Mentouri Constantine | Rolland M.,Montpellier University | Sainte-Catherine O.,CNRS Laboratory of Chemistry, Structures, Biomaterials Properties and Therapeutic Agents | And 6 more authors.
European Journal of Medicinal Chemistry | Year: 2015

This paper describes the preparation and the biological evaluation of α-halogenated oxaphosphinanes. These halogen derivatives were synthetized from a short and stereoselective synthetic sequence starting by previously described hydroxy-precursors 1 and 2 with respectively a glucose and mannose-like configuration. The in vitro biological tests of these unnatural halogenated phosphinosugars, on several cell lines, highlighted, for some of them, their antiproliferative and anti migration and invasion properties at nanomolar concentration.α-Halogenated (I, Br, Cl) oxaphosphinanes were obtained stereoselectively from a two-step sequence, via a phase transfer catalyzed reaction.An unusual rearrangement was observed leading to furanosylphosphinic acid.In vitro biological tests on several cell lines, highlighted their antiproliferative properties at nanomolar concentration. © 2015 Elsevier Masson SAS.

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