De nombreuses études ont montré l'intérêt thérapeutique de molécules dérivant des microARN (inhibiteurs ou analogues) en cancérologie. Cependant avant d'espérer en faire de futurs médicaments, il est indispensable d'élaborer des systèmes permettant leur délivrance préférentielle dans les cellules cancéreuses. Dans ce travail, nous avons développé deux plateformes innovantes basées sur les microARN : la première utilise les propriétés optiques des quantum dots (QD) et est destinée à l'imagerie des microARN ; la seconde repose sur la sérum albumine humaine (SAH) et a une finalité de délivrance ciblée de microARN. La mise en place de ces plateformes a nécessité la synthèse d'une petite chimiothèque de bioconjugués lipidiques dérivés des microARN (inhibiteurs ou analogues), le but étant d'exploiter l'effet hydrophobe pour les fixer à la surface des QD (ancrage hydrophobe dans la paroi lipidique des QD) et de la SAH (interaction avec les sites de liaison aux acides gras). Dans les deux cas, différentes études incluant des caractérisations physico-chimiques (MET, DLS), des expériences in vitro (SPR) et in cellulo (microscopie de fluorescence, criblage fonctionnel, RTqPCR) ont montré la potentialité de ces nouvelles plateformes. / Exploitation of gene-silencing is a very promising strategy in human therapeutics. Several engineered small non coding RNAs (inhibitors or mimics) are already in preclinical and clinical trials. However a key impediment to the wider success of these approaches remains the specific delivery of RNA-derived molecules into cancerous cells. This work aimed at developing two innovative microRNA-based plateforms : the first one relying on quantum dots (QD) is dedicated to microRNA imaging and the second one based on human serum albumin (HSA) represents a new targeted delivery system. The implementation of both plateforms required the synthesis of a small library of microRNA derived lipidic bioconjugates (inhibitors or mimics), the aim being to exploit the hydrophobic effect for their loading on QD (hydrophobic anchoring in the hydrophobic QD surface) and on HSA (interaction with fatty acid binding sites). In both cases, different studies including physico-chemical caracterizations (TEM, DLS), in vitro (SPR) and in cellulo experiments (fluorescence microscopy, functional screening, RTqPCR) demonstrated the great promises held by these new plateforms.

Pseudomonas aeruginosa (PA) représente un véritable problème de santé publique étant l'une des principales causes d'infections nosocomiales et de mortalité chez les patients atteints de fibrose cystique. Cette bactérie provoque des pathologies respiratoires chroniques qui persistent malgré une thérapie antibiotique agressive à cause de l'émergence de souches résistantes et de la formation du biofilm. Une stratégie prometteuse consiste à inhiber les facteurs de virulence de PA tels que PA-IL qui est une lectine soluble impliquée dans la reconnaissance des résidus galactose et qui semble jouer un rôle dans l'adhésion de la bactérie au glycocalyx autour de la cellule hôte ainsi que dans le développement du biofilm. Alors que les interactions lectine-carbohydrate sont caractérisées par une spécificité élevée, l'affinité entre les lectines et les saccharides simples est faible et une présentation multivalente des unités saccharidiques est généralement requise pour atteindre une interaction significative d'un point de vue physiologique. Ce manuscrit décrit la synthèse de glycooligonucléotides dont l'affinité envers PA-IL a été étudiées par DNA Direct Immobilisation microarray. Les blocs de construction saccharidiques ont été assemblés sur des échafaudages phosphorylés en utilisant une combinaison de synthèse en phase solide d'ADN et « click chemistry » (cycloaddition 1,3-dipolaire azide/alcyne). Grâce à la technologie glycoarray, les glycomimétiques ont été analysés à une échelle nanomolaire. Les résultats expérimentaux ont permis d'établir des relations structure-activités précises. En outre, des études des docking ont confirmé les résultats expérimentaux. La synthèse des candidats les plus affins envers PA-IL a été conduite sans l'étiquette d'ADN et à plus grande échelle pour vérifier par des analyses biologiques leurs propriétés anti-adhésives ou inhibitrices du biofilm. / Pseudomonas aeruginosa (PA) is a major public health issue due to its impact on nosocomial infections as well as its impact on cystic fibrosis patient mortality. It often leads to chronic respiratory infection despite aggressive antibiotic therapy due to the emergence of resistant strains and to the formation of biofilm. A promising approach is to inhibit the virulence factors of PA such as PA-IL which is a soluble lectin implicated in the recognition of galactose residues that seems to be involved in the adhesion of the bacterium to the glycocalyx surrounding host's cells as well as in the biofilm development.If carbohydrate-lectin interactions proceed with high specificity, the affinity between lectins and simple saccharides is low and a multivalent display of saccharidic units is generally required to attain physiologically significant association. This manuscript reports the synthesis of high affinity glycooligonucleotides toward PA-IL for its inhibition and their bindings properties were studied on a DNA direct immobilisation microarray. Glycoside building blocks were assembled on phosphorylated scaffolds using a combination of DNA solid phase synthesis and microwave assisted « click chemistry » (copper (I) catalyzed 1,3-dipolar cycloaddition). Thanks to glycoarray technology the glycomimetics were studied at the nanomole scale. The experimental results have been used to assess structure binding relationships. In addition, docking studies have confirmed ours experimental results. The synthesis of the best hits as anti-biofilm or anti-adhesive molecules have been synthesized at upper scale without their DNA tag for biological studies as anti-adhesive compounds and biofilm inhibitors of PA.

by Lai Wing Hong Kevin. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1995. / Includes bibliographical references (leaves 63-74). / Acknowledgments --- p.i / Abbreviations --- p.ii / Abstract --- p.1 / Chapter Chapter 1 --- General Introduction --- p.3 / Chapter 1.1 --- Advantages of Antisense Oligonucleotides Inhibition --- p.4 / Chapter 1.2 --- The Uses of Antisense Oligonucleotide in Leukemic Therapy --- p.5 / Chapter 1.3 --- Oncogenes in the Pathogenesis of Leukemia --- p.6 / Chapter 1.4 --- Apoptosis and Apoptosis-Related Genes --- p.9 / Chapter 1.5 --- Protooncogene bcl-2 --- p.10 / Chapter 1.6 --- Bcl-2 Homologues --- p.11 / Chapter 1.7 --- Regulation of Apoptosis by Other Genes --- p.13 / Chapter 1.8 --- Promyelocytic Leukemia HL-60 Cell Line --- p.15 / Chapter 1.9 --- Aim of Project --- p.16 / Chapter Chapter 2 --- Chemical Synthesis of DNA Oligonucleotides / Chapter 2.1 --- Introduction --- p.17 / Chapter 2.2 --- Materials and Methods --- p.20 / Chapter 2.3 --- Results --- p.24 / Chapter 2.4 --- Discussion --- p.26 / Chapter Chapter 3 --- The Apoptotic Effects of TPA and Ouabain on the Promyelocytic Leukemic HL-60 cell line / Chapter 3.1 --- Introduction --- p.30 / Chapter 3.2 --- Materials and methods --- p.33 / Chapter 3.3 --- Results --- p.40 / Chapter 3.4 --- Discussion --- p.44 / Chapter Chapter 4 --- Effect of Antisense Oligonucleotides on TPA-Induced Apoptosisin Leukemic HL-60 cells / Chapter 4.1 --- Introduction --- p.48 / Chapter 4.2 --- Materials and Methods --- p.49 / Chapter 4.3 --- Results --- p.52 / Chapter 4.4 --- Discussion --- p.54 / Chapter Chapter 5 --- General Discussion --- p.57 / References --- p.63

by Lai Mei Yi. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves 130-136). / Abstracts in English and Chinese. / Acknowledgment --- p.i / Abstract --- p.ii / 論文撮耍 --- p.v / List of Figures --- p.viii / List of Tables --- p.xi / Abbreviations --- p.xii / Table of content --- p.xiii / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Facilitative glucose transporters --- p.1 / Chapter 1.1.1 --- Predicted Secondary structure of Glutl --- p.1 / Chapter 1.1.2 --- The tissue-specific distribution of glucose transporters --- p.2 / Chapter 1.2 --- Increase of glucose uptake in cancer cells --- p.5 / Chapter 1.3 --- Antisense oligonucleotide therapeutics --- p.7 / Chapter 1.3.1 --- Chemical modifications of oligonucleotides --- p.7 / Chapter 1.3.2 --- Cellular Uptake of Oligonucleotide --- p.11 / Chapter 1.3.3 --- Mechanism of action --- p.13 / Antisense-mediated RNA Cleavage --- p.14 / """Occupancy-only"" mediated mechanism" --- p.15 / Chapter 1.3.4 --- Antisense treatment in vivo --- p.17 / Chapter 1.4.5 --- Human Studies of Antisense Treatment --- p.18 / Chapter Chapter 2 --- Materials & Methods --- p.20 / Chapter 2.1 --- Materials --- p.20 / Chapter 2.2 --- Cell Culture --- p.21 / Chapter 2.2.1 --- Human colon adenocarcinoma cell Line (Caco-2) --- p.21 / Chapter 2.3 --- General Methodology for treatment of cells with antisense oligonucleotides --- p.22 / Chapter 2.3.1 --- Treatment of cells with oligonucleotides --- p.22 / Chapter 2.4 --- Cytotoxicity Assay --- p.23 / Chapter 2.4.1 --- MTT assay --- p.23 / Chapter 2.4.2 --- 3H-thymidine incorporation --- p.23 / Chapter 2.5 --- RNA extraction --- p.24 / Chapter 2.6 --- Competitive Reverse-transcription polymerase chain reaction (RT-PCR) of glucose transporters --- p.25 / Chapter 2.7 --- Measurement of 2-deoxy-D-glucose and Fructose transport --- p.27 / Chapter 2.8 --- Western blotting --- p.28 / Chapter 2.9 --- Flow cytometry --- p.30 / Chapter 2.9.1 --- Measurement of cellular accumulation of fluorophore-labeled oligonucleotide --- p.30 / Chapter 2.10 --- Design of antisense oligonucleotide --- p.31 / Chapter 2.11 --- ATP assay --- p.34 / Chapter 2.12 --- Animals studies --- p.35 / Chapter Chapter 3 --- Optimization of phosphorothioate antisense oligonucleotide delivery by Lipofectin --- p.36 / Chapter 3.1 --- Introduction --- p.36 / Chapter 3.2 --- Measurement of oligonucleotide uptake --- p.38 / Chapter 3.2.1 --- Lipofectin as a delivery system for the oligonucleotide uptake --- p.39 / Chapter 3.2.2 --- Effect of Lipofectin ratio on the oligonucleotide uptake --- p.41 / Chapter 3.2.3 --- Effect of oligonucleotide concentration on the oligonucleotide uptake --- p.41 / Chapter 3.2.4 --- Effect of incubation time on the oligonucleotide uptake --- p.44 / Chapter 3.2.5 --- Effect of oligonucleotide length on cellular uptake --- p.44 / Chapter 3.3 --- Effect of Lipofectin on cell viability --- p.47 / Chapter Chapter 4 --- In vitro effect of Antisense Oligonucleotides against glucose transporters on Caco-2 Cell --- p.49 / Chapter 4.1 --- Introduction --- p.49 / Chapter 4.2 --- Design of Antisense Oligonucleotides against Glucose Transporters gene --- p.50 / Chapter 4.3. --- Antisense effect of different regions of antisense oligonucleotide --- p.52 / Chapter 4.4 --- Antisense and Sense effect of oligonucleotide against start codon (G5 7015) on Caco-2 cells --- p.59 / Chapter 4.4.1 --- Effect of oligonucleotide to Lipofectin ratio on cell viability --- p.59 / Chapter 4.4.2 --- Dose-Response Study: effect of concentration of antisense - oligonucleotide on cell viability --- p.61 / Chapter 4.4.3 --- Effect of length´ؤof oligonucleotide on cell viability --- p.61 / Chapter 4.4.4 --- Time-Response Study: effect of antisense oligonucleotide on cell viability --- p.66 / Chapter 4.5 --- "The effect of antisense oligonucleotide against Glut1, Glut3 and Glut5 on cell viability of Caco-2 cells" --- p.70 / Chapter 4.6 --- Analysis of ATP content in Caco-2 cells by using antisense oligonucleotide flanking start codon (G5 7015) --- p.72 / Chapter 4.7 --- Effect of G5 7015 on HepG2 cells --- p.72 / Chapter Chapter 5 --- Effect of antisense oligonucleotides against Glut5 on mRNA and Protein levels of Glut5 gene --- p.76 / Chapter 5.1 --- Introduction --- p.76 / Chapter 5.2 --- RT-PCR of Glut isoform in Caco-2 cells --- p.77 / Chapter 5.3 --- Effect of antisense oligonucleotides against Glut 5 on mRNA level in Caco-2 cells --- p.77 / Chapter 5.3.1 --- Effect of oligonucleotides targeted different region of Glut5 gene on Glut5 message level --- p.77 / Chapter 5.3.2 --- Reduction in expression of mRNA level of Glut5 by using antisense oligonucleotides targeting start codon (G5 7015) --- p.81 / Chapter 5.3.3 --- Study of the dose and time dependence on inhibition of mRNA expression in G5 7015 treated Caco-2 cells --- p.83 / Chapter 5.3.4 --- Cross-Inhibition of antisense targeting glucose transporter isoforms --- p.83 / Chapter 5.4 --- Reduction in Glut5 protein level using G5 7015 antisense oligonucleotide --- p.86 / Chapter 5.5 --- Inhibition of Glut5 activity using G57015 oligonucleotide --- p.88 / Chapter 5.6 --- Inhibition of Glut5 mRNA level in vivo --- p.93 / Chapter Chapter 6 --- The possible role for Glucose Transporters in the Modification of Multidrug Resistance in Tumor cells --- p.95 / Chapter 6.1 --- Introduction --- p.95 / Chapter 6.2 --- Materials & Methods --- p.97 / Chapter 6.2.1 --- Cell culture --- p.97 / Chapter 6.2.2 --- Chemicals --- p.98 / Chapter 6.2.3 --- Measurement of doxorubicin uptake --- p.99 / Chapter 6.3 --- The expression of P-glycoprotein and Doxorubicin resistance of R-HepG2 cells --- p.99 / Chapter 6.4 --- Comparison of H3-2-deoxyglucose uptake between HepG2 and R-HepG2 cells --- p.99 / Chapter 6.5 --- Quantification of Glut1 and Glut3 expression by RT-PCR --- p.102 / Chapter 6.6 --- Comparison of doxorubicin between HepG2 and R-HepG2 cells cultured accumulation in glucose free medium --- p.104 / Chapter 6.7 --- The time course of doxorubicin accumulation in R-HepG2 cells culturing in glucose free medium --- p.106 / Chapter 6.8 --- "Cell viability of R-HepG2 cells after treatment of glucose transporter inhibitors, phloretin (PT), cytochalasin B (CB) and mitochondrial inhibitor，2,4-Dinitrophenol (DNP)" --- p.106 / Chapter 6.9 --- "Effect of glucose transporter inhibitors (PT, CB) and mitochondrial inhibitor (DNP) on doxorubicin accumulationin R-HepG2" --- p.110 / Chapter 6.10 --- Effect of antisense oligonucleotide against Glutl on doxorubicin accumulation in R-HepG2 cell --- p.113 / Chapter 6.11 --- "Analysis of ATP content and 3H-2-deoxy-D-glucose uptakein R-HepG2 after treatments of PT, CB and DNP" --- p.115 / Chapter Chapter 7 --- Discussion --- p.117 / Chapter 7.1 --- Antisense oligonucleotide against glucose transportersin Caco-2 cell --- p.117 / Chapter 7.2 --- Cellular uptake of oligonucleotide --- p.119 / Chapter 7.3 --- In vitro study of using antisense oligonucleotide against Glut5 --- p.121 / Chapter 7.4 --- In vivo study of using antisense oligonucleotide against Glut5 --- p.126 / Chapter 7.5 --- Possible role of inhibition of glucose transport in reversing P- gp --- p.127 / Chapter Chapter 8 --- References --- p.130

Les oligonucléotides antisens et leurs analogues, tels que les Peptide Nucleic Acids (PNA), ont la capacité d'inhiber ou de moduler l'expression d'un gène cible, de manière spécifique de séquence. Leur utilisation pour des applications thérapeutiques est cependant limitée par leur faible internalisation cellulaire ou leur mauvaise localisation intracellulaire, etnécessite le développement de stratégies efficaces de vectorisation. La Riboflavine, ou vitamine B2, est une vitamine essentielle qui a les caractéristiques requises pour être potentiellement utilisée en tant qu'agent ciblant de vectorisation. Le travail accompli au cours de ce projet de thèse a permis de démontrer la capacité de deux dérivés de la Riboflavine, la Flavine et le Lumichrome, à induire une internalisation par endocytose de PNA conjugués, dans plusieurs lignées cellulaires. En outre, un phénomène d'internalisation photochimique induit par la Rhodamine a été mis en évidence avec des double-conjugués Flavine ou Lumichrome - PNA - Rhodamine et conduit à une sortie efficace des endosomes de ces conjugués. Ce travail de thèse a donc permis de caractériser un conjugué trifonctionnel pour l'internalisation et lalibération cytoplasmique de molécules bioactives. / Antisense oligonucleotides and analogs, such as Peptide Nucleic Acids (PNA), are valuable tools to inhibit or modulate gene expression in a sequence-specific manner. Their successful application for therapeutic purposes is however hampered by poor cellular uptake or incorrect intracellular localization, and requires the development of efficient delivery strategies.Riboflavin, or vitamin B2, is an essential vitamin that could potentially be used as a targeting delivery ligand. We demonstrate in this PhD work the ability of two Riboflavin derivatives, Flavin and Lumichrome, to promote endocytosis-mediated internalization of PNA conjugates in several cell lines. Furthermore, a phenomenon of Photochemical Internalization produced by Rhodamine has been characterized using Flavin or Lumichrome - PNA - Rhodamine conjugatesand is responsible for an efficient release of these conjugates from endosomes. This PhD work has thus led to the characterization of a trifunctional conjugate for the internalization and cytoplasmic delivery of bioactive molecules.

Chung Ka Wing. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 151-162). / Abstracts in English and Chinese. / Contents --- p.i / Acknowledgements --- p.v / Abstract --- p.vi / 論文摘要 --- p.ix / List of Abbreviations --- p.xi / List of Figures --- p.xiii / List of Tables --- p.xv / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Breast Cancer --- p.2 / Chapter 1.1.1 --- Incidence Rate of Breast Cancer --- p.2 / Chapter 1.1.2 --- Risk Factors Lead to Breast Cancer --- p.5 / Chapter 1.1.3 --- Conventional Treatments --- p.5 / Chapter 1.2 --- Relationship between Breast Cancer and Glucose Transporters --- p.7 / Chapter 1.2.1 --- Importance of Glucose and Fructose --- p.7 / Chapter 1.2.2 --- Facilitative Glucose Transporters (Gluts) and The Relationship with Breast Cancer --- p.7 / Chapter 1.3 --- Antisense Oligonucleotides --- p.13 / Chapter 1.3.1 --- Characteristics of Antisense Oligonucleotides --- p.13 / Chapter 1.3.2 --- Action Mechanism of Antisense Oligonucleotides --- p.15 / Chapter 1.3.3 --- Sequence Selection --- p.19 / Chapter 1.3.4 --- Chemical Modifications of Antisense Oligonucleotides --- p.20 / Chapter 1.3.5 --- Uptake and Delivery Means of Antisense Oligonucleotides --- p.24 / Chapter 1.4 --- Objectives of Present Study --- p.26 / Chapter Chapter 2 --- Materials and Methods --- p.31 / Chapter 2.1 --- Materials --- p.32 / Chapter 2.1.1 --- Cell Lines and Culture Medium --- p.32 / Chapter 2.1.2 --- Buffers and Reagents --- p.33 / Chapter 2.1.3 --- Reagents for Transfection --- p.34 / Chapter 2.1.4 --- Reagents for D-[U14C]-Fructose and 2-Deoxy-D-[l-3H] Glucose Uptake Assay --- p.35 / Chapter 2.1.5 --- Reagents for ATP Assay --- p.35 / Chapter 2.1.6 --- Reagents for RT-PCR --- p.36 / Chapter 2.1.6.1 --- Reagents for RNA Extraction --- p.36 / Chapter 2.1.6.2 --- Reagents for Reverse Transcription --- p.36 / Chapter 2.1.6.3 --- Reagents for Gel Electrophoresis --- p.37 / Chapter 2.1.7 --- Reagents for Real Time-PCR --- p.38 / Chapter 2.1.8 --- Reagents and Chemicals for Western Blotting --- p.39 / Chapter 2.1.8.1 --- Reagents for Protein Extraction --- p.39 / Chapter 2.1.8.2 --- Reagents for SDS-PAGE --- p.39 / Chapter 2.1.9 --- Reagents for Flow Cytometry --- p.42 / Chapter 2.1.10 --- In Vivo Study --- p.43 / Chapter 2.2 --- Methods --- p.44 / Chapter 2.2.1 --- Oligonucleotide Design --- p.44 / Chapter 2.2.2 --- Trypan Blue Exclusion Assay --- p.47 / Chapter 2.2.3 --- Transfection --- p.47 / Chapter 2.2.4 --- MTT Assay --- p.47 / Chapter 2.2.5 --- D-[U14C]-fructose and 2-deoxy-D-[l-3H] Glucose Uptake Assay --- p.48 / Chapter 2.2.6 --- Detection of Intracellular ATP Concentration --- p.49 / Chapter 2.2.7 --- Reverse Transcription-Polymerase Chain Reaction (RT-PCR) --- p.51 / Chapter 2.2.7.1 --- RNA Extraction by TRIzol Reagent --- p.51 / Chapter 2.2.7.2 --- Determination of RNA Concentration --- p.51 / Chapter 2.2.7.3 --- Reverse Transcription --- p.52 / Chapter 2.2.7.4 --- Polymerase Chain Reaction (PCR) --- p.52 / Chapter 2.2.8 --- Real-Time PCR --- p.55 / Chapter 2.2.8.1 --- Analysis of the Real-Time PCR Data --- p.57 / Chapter 2.2.9 --- Western Blot Analysis --- p.58 / Chapter 2.2.9.1 --- Protein Extraction --- p.58 / Chapter 2.2.9.2 --- Protein Concentration Determination --- p.58 / Chapter 2.2.9.3 --- Western Blotting --- p.60 / Chapter 2.2.10 --- Flow Cytometry --- p.62 / Chapter 2.2.10.1 --- Detection of Cell Cycle Pattern with PI --- p.62 / Chapter 2.2.10.2 --- Detection of Apoptosis with Annexin V/PI --- p.62 / Chapter 2.2.11 --- In Vivo Study --- p.63 / Chapter 2.2.11.1 --- Establishment of Tumor-Bearing Animal Model --- p.63 / Chapter 2.2.11.2 --- Treatment Schedule --- p.63 / Chapter 2.2.11.3 --- Toxicity of Antisense Oligonucleotides --- p.64 / Chapter Chapter 3 --- Results --- p.66 / Chapter 3.1 --- In Vitro Study --- p.67 / Chapter 3.1.1 --- Effect of Tamoxifen on MCF-7 cells and MDA-MB-231 cells --- p.67 / Chapter 3.1.2 --- Cytotoxicity of Antisense Oligonucleotides against Glut 5 on MCF-7 cells and MDA-MB-231 cells by MTT Assay --- p.69 / Chapter 3.1.3 --- Effect of Antisense Oligonucleotides against Glut 5 on Fructose and Glucose Uptake of MCF-7 cells and MDA-MB-231 cells by D-[U14C]-Fructose & 2-Deoxy-D-[l-3H] Glucose Uptake Assay --- p.77 / Chapter 3.1.4 --- Effect of Antisense Oligonucleotides against Glut 5 on Intracellular ATP Content of MCF-7 cells and MDA-MB-231 cells by ATP Assay --- p.81 / Chapter 3.1.5 --- Effect of Antisense Oligonucleotides against Glut 5 on Glut 5 RNA Expression of MCF-7 cells and MDA-MB-231 cells by RT-PCR and Real-Time PCR --- p.83 / Chapter 3.1.5.1 --- RT-PCR --- p.83 / Chapter 3.1.5.2 --- Real-Time PCR --- p.87 / Chapter 3.1.6 --- Effect of Antisense Oligonucleotides against Glut 5 on Glut 5 Protein Expression of MCF-7 cells and MDA-MB-231 cells by Western Blot Analysis --- p.89 / Chapter 3.1.7 --- "Effect of Antisense Oligonucleotides against Glut 5 on Change in Cell Cycle Pattern of MCF-7 cells and MDA-MB-231 cells by Flow Cytometry, Using PI Stainning" --- p.93 / Chapter 3.1.8 --- "Effect of Antisense Oligonucleotides against Glut 5 on Induction of Apoptosis of MCF-7 cells and MDA-MB-231 cells by Flow Cytometry, Using Annexin V-FITC Stainning" --- p.98 / Chapter 3.2 --- In Vivo Study --- p.101 / Chapter 3.2.1 --- Animal Model: Nude Mice --- p.101 / Chapter 3.2.2 --- Effect of Antisense Oligonucleotides against Glut 5 on the MCF-7 cells-Bearing Nude Mice --- p.101 / Chapter 3.2.2.1 --- Change of Weight of the Tumor-Bearing Nude Mice --- p.101 / Chapter 3.2.2.2 --- Tumor Growth Rate --- p.105 / Chapter 3.2.2.3 --- Glut 5 RNA Expression by Real-Time PCR --- p.109 / Chapter 3.2.2.4 --- Glut 5 RNA Expression by Western Blotting --- p.111 / Chapter 3.2.3 --- "Assessment of Side Effects of Antisense Oligonucleotides against Glut 5, by Measuring the Plasma Enzyme Level" --- p.113 / Chapter Chapter 4 --- Discussion --- p.118 / Chapter 4.1 --- Antisense Oligonucleotides against Glut 5 on Human Breast Cancer --- p.119 / Chapter 4.1.1 --- Antisense Oligonucleotides Strategy --- p.119 / Chapter 4.1.2 --- Role of Glut 5 in Breast Cancer --- p.123 / Chapter 4.1.3 --- Effects of Tamoxifen on MCF-7 and MDA-MB-231 --- p.126 / Chapter 4.2 --- In Vitro Study of Antisense Oligonucleotides against Glucose Transporter 5 on Breast Cancer Cells --- p.127 / Chapter 4.3 --- In Vivo Study of Antisense Oligonucleotides against Glucose Transporter 5 on Breast Cancer Cells --- p.135 / Chapter 4.3.1 --- Effects of Antisense Oligonucleotides against Glut 5 on Body Weight and Tumor Size --- p.137 / Chapter 4.3.2 --- Expression Level of Glut 5 of the Tumor --- p.138 / Chapter 4.3.3 --- Assessment of Side Effects of Antisense Oligonucleotides against Glut 5，by Measuring the Plasma Enzymes Level --- p.140 / Chapter 4.4 --- Possible Mechanism of Antisense Oligonucleotides against Glut 5 on Breast Cancer --- p.141 / Chapter Chapter 5 --- Future Prospectus and Conclusions --- p.143 / Chapter 5.1 --- Future Prospectus of Antisense Oligonucleotides --- p.144 / Chapter 5.1.1 --- Antisense Oligonucleotides and Treatment of Breast Cancer --- p.144 / Chapter 5.1.2 --- Role of Glut 5 in Breast Cancer --- p.147 / Chapter 5.2 --- Conclusions and Remarks --- p.148 / References --- p.151

Les oligonucleotides sont utilisés pour de nombreuses applications dans le domaine du diagnostic et ils peuvent également être utilisés comme traitement pour de nombreuses maladies. Les oligonucléotides sont des polyanions qui viennent s'hybrider sur leurs séquences complémentaires elles aussi anioniques. Les répulsions électrostatiques impliquent que l'addition de charges positives sur les oligonucléotides serait bénéfique pour diminuer les répulsions et améliorer l'hybridation. Dans le but de diminuer ces répulsions électrostatiques, des conjugués oligonucléotide-oligocation sur lesquels sont greffées des unités spermines ont été développés. Les conjugués oligonucléotideoligocation sont synthétisés sur un synthétiseur automatique d'oligonucléotide en utilisant la chimie des phosphoramidites. Les« Zip Nucleic Acid »ou ZNAs sont des oligonucléotides portant une queue cationique de quelques unités de spermine et sont de charge globale négative. Les modifications apportées permettent d'améliorer l'hybridation en accélérant la reconnaissance de la séquence cible et en augmentant la température de fusion linéairement avec le nombre de spermines greffées sans altérer la spécificité. Les ZNAs se révèlent être efficaces utilisés comme amorces ou sondes en PCR et ils apparaissent comme de nouveaux outils intéressants pour la biologie moléculaire. Les petits ARNintérferents (si RNA) induisant l'extinction d'un gène par la voie d' ARN interférence ont suscités un grand engouement ces dernières années, cependant leur très faible pénétration cellulaire est un frein majeur à leur utilisation. C'est pour cela que les conjugués oligonucléotide- oligospermine ont un réel intérêt pour le domaine de la thérapie in vivo. Les duplexes SIRNAPLUS cationiques sont des siRNAs ciblantspécifiquement un ARN messager. Ils sont constitués d'un brin sens ARN-oligospermine de charge globale positive hybridé à un brin antisens. Les résultats ont montré que lesSIRNAPLUS pouvaient entrer seuls dans les cellules sans agent de transfert pour induire l'extinction d'un gène cible et les premières expériences montrent qu'ils sont actifs in vivo. Mes travaux de thèse ont porté sur le développement des conjugués oligonucléotide oligospermine et démontrent des applications potentielles dans le domaine du diagnostic et de la thérapie. / Oligonucleotides are finding an extremely large number of applications in molecular diagnostics and might become a very selective class of drugs for the treatment of a vast palette of diseases. Oligonucleotides are polyanions that exert their specifie activity following hybridization to a complementary sequence borne by another polyanionic nucleic acid. Simple electrostatic considerations imply that hybridization energy and cell binding couId benefit from addition of cationic groups to the oligonucleotide structure. Towards the aim of improving hybridization by decreasing electrostatic repulsions between the negatively charged strands, oligonucleotide-oligocation conjugates whose global charge is modulated by the number of cationic spermine moieties grafted on the oligonucleotides have been developed. Oligonucleotide-oligospermine conjugates are produced using an automated solid-phase synthesis of conjugates that are entirely based on the phosphoramidite coupling chemistry. Zip Nucleic Acids {ZNAs} are oligonucleotides with a short polycationic tail, composed of relatively few spermine units, leading to molecules overall negative in charge. The modification improves hybridisation by accelerating the target recognition and increases the melting temperature linearly with the number of grafted spermines on the oligonucleotide without altering the specificity. ZNAs have been shown to be potent primers and probes for PCR and are new interesting tools for molecular biology and diagnostics applications. Small interfering RNA (siRNA}-mediated gene silencing has become a drug development paradigm. As drug candidates, they must aIso be able to cross the anionic cell membrane. However, still one major limitation of the use of siRNA remains their inability to penetrate efficiently into cells of a particular tissue or tumour. That gives to oligonucleotide-oligospermine conjugates a real interest in this domain and more generally in vivo therapies. Cationic SIRNAPLUS are duplexes of small RNAs targeting a specifie mRNA. They are produced as an oligospermine-RNA sense strand, with positive global charge, associated to an antisense RNA strand. Results have shown that cationic siRNAs are able to enter cells efficiently without vector and to display silencing activity at nanomolar concentration. To have positive global charge, the number of spermine moieties has been increased. Purification and characterization methods have been developed to have cationic siRNAs compatible with in vivo experiments. My thesis will describe the synthesis of oligonucleotide-oligospermine conjugates as well as their applications.

Un très grand nombre de travaux de recherche fait état de l’intérêt des oligonucléotides en tant qu’agents thérapeutiques. Les modes d’actions envisageables sont très variés (thérapie antisens, antigène, interférence ARN, etc.). Cependant, les propriétés pharmacocinétiques et pharmacodynamiques des oligonucléotides naturels ne permettent pas leurs utilisations in vivo. Leurs propriétés peuvent être améliorées par des modifications chimiques. Notre travail consiste à synthétiser une nouvelle génération d’oligoribonucléotides modifiés : les oligomères de nucléosides aminooxy acides. Dans ces oligomères, la liaison phosphodiester de l’ARN est remplacée par une liaison N-oxyamide -CONHO-. Cette liaison est stable vis-à-vis des hydrolyses chimiques et enzymatiques et est facilement engagée dans des liaisons hydrogène. La préparation de différents nucléosides aminooxy esters protégés à partir de l’uridine ou du D-(+)-glucose est présentée. Par ailleurs, les N-oxy PNA constituent une autre famille d’oligonucléotides modifiés présentant une liaison N-oxyamide. L’analyse structurale des monomères et des dimères de N-oxy PNA est détaillée.De plus, un projet en collaboration avec le LBPA s’intéresse à une méthode de détermination de la structure secondaire des ARN. Dans ce but, nous avons conçu, synthétisé et étudié des sondes chimiques ciblant le ribose des nucléotides non appariés d’ARN. L’emploi de catalyseurs nucléophiles comme la DMAP permet d’augmenter la réactivité des sondes. / A large number of researches report the interest of oligonucleotides as therapeutic agents. The modes of actions are very varied (antisense therapy, antigen therapy, RNA interference, etc.). However, the pharmacokinetic and pharmacodynamic properties of natural oligonucleotides do not allow their in vivo uses. Their properties can be improved by chemical modifications. Our work consists to synthesize a new generation of modified oligoribonucleotides: the oligomers of aminooxy acids nucleosides. In such oligomers, the phosphodiester bond of the RNA is replaced with a N-oxyamide bond -CONHO-. This linkage is stable to chemical and enzymatic hydrolysis and is easily engaged in hydrogen bondings. The preparation of different protected aminooxy esters nucleosides starting from uridine or D-(+)-glucose is presented. Furthermore, N-oxy PNA constitute another family of modified oligonucleotides having a N-oxyamide bond. Structural analysis of the monomers and the dimers of N-oxy PNA is detailed.In addition, a project in collaboration with the LBPA focuses on a method for determining the secondary structure of RNA. To this end, we designed, synthesized and studied chemical probes targeting ribose of unpaired nucleotides. The use of nucleophilic catalysts such as DMAP increases the reactivity of the probes.

Nanoemulsões catiônicas têm sido consideradas como potenciais sistemas carreadores para oligonucleotídeos (ON) antisenso. O objetivo do presente trabalho foi desenvolver nanoemulsões catiônicas como um sistema de liberação para ON anti-topoisomerase II de Plasmodium falciparum. Primeiramente, nanoemulsões constituídas de triglicerídeos de cadeia média, lecitina de gema de ovo, glicerol e água contendo os lipídeos catiônicos oleilamina ou DOTAP (2 mM) foram obtidas através do procedimento de emulsificação espontânea. Este procedimento resultou em formulações monodispersas com diâmetro de gotícula de 200-260 nm e potencial zeta de +50 e +55 mV. Após, um método espectrofotométrico no UV para quantificação dos ON em série fosfodiéster (PO) ou fosforotioato (PS) foi validado. O método mostrou-se linear, específico, preciso e exato para a determinação de PO e PS, sem diferenças significativas entre os ON. Nas condições validadas, as isotermas de adsorção dos ON às nanoemulsões foram obtidas através da determinação dos ON na fase aquosa externa das nanoemulsões, após ultrafiltração/centrifugação dos complexos. A taxa de recuperação através das membranas de ultrafiltração de celulose regenerada (30 kDa) foi superior a 92%. Os resultados indicam a adsorção progressiva dos ON com as nanoemulsões, até cerca de 60 mg/g de fase interna para o complexo DOTAP-PS. Finalmente, evidências adicionais da adsorção de PO e PS às nanoemulsões foram detectadas pelo aumento do diâmetro de gotícula, inversão do potencial zeta e morfologia das gotículas avaliada por microscopia eletrônica de transmissão. O conjunto dos resultados obtidos demonstra que ON de série PO e PS anti-topoisomerase II de P. falciparum podem ser adsorvidos eficientemente às nanoemulsões catiônicas. / Cationic nanoemulsions have been recently considered as a potential delivery system for antisense oligonucleotides (ON). The aim of the present work was to evaluate cationic nanoemulsions as a delivery system for ON against the Plasmodium falciparum topoisomerase II gene. Firstly, nanoemulsions composed of medium chain triglycerides, egg yolk lecithin, glycerol and water, containing the cationic lipids oleylamine or DOTAP (2 mM) were obtained through spontaneous emulsification process. This procedure resulted in monodisperse formulations with droplet size of 200-260 nm and zeta potential of +50 and +55mV. After that, an UV spectrophotometric method for the quantification of either phosphodiester (PO) or phosphorothioate (PS) ON was validated. The method was linear, specific, precise, and accurate for the determination of PO and PS, without significant differences between both ON. In the validated conditions, ON adsorption isotherms with nanoemulsions were obtained through the ON determination in the external phase of nanoemulsions, after ultrafiltration/centrifugation of complexes. The recovery through regenerated cellulose membranes (30kDa) was higher than 92%. The results showed a progressive ON adsorption to the nanoemulsions up to approximately 60mg/g of internal phase for DOTAP-PS complexes. Finally, additional evidences of PO and PS adsorption to nanoemulsions could also be detected by the increase of the mean droplet size, the inversion of the zeta potential and the morphology of the oil droplets obtained by transmission electron microscopy. The overall results showed that PO and PS ON against P. falciparum anti-topoisomerase II gene can be efficiently adsorbed to the cationic nanoemulsions.

Cancer remains one of the most feared diseases affecting the modern world. Second to heart disease, it is the largest cause of deaths, affecting one in three persons. Cancer cells are formed when normal, healthy cells become damage, losing their normal regulatory mechanism that control cell growth. There are many different types and progression of these cancer cells that determine the type of treatment a patient receives. The primary focus of this dissertation is to propose three studies of anticancer agents. In Chapter one, a CpG-lytic peptide conjugate was designed to target receptors on the cell membrane to concentrate the lytic peptide around the cells to cause triggered cell death, in the treatment of Myelodysplastic Syndromes (MDS). This conjugate act like monoclonal antibodies in that the molecular size is too large to enter the cell, therefore it targets the TLR9 receptors expressed extracellularly in precancer cells in MDS. Chapter two, focuses on the screening of anticancer agents used in targeted therapy. It provides a general scheme applied to the synthesis of a combinatorial library of primary amines used as small-molecule drugs coupled unto a solid support bead (Positional Scanning Library Method) to screen for biological effects on various types of cancers. Chapter three address the issue of radiotherapy treatments, one of the most widely used treatment of cancer. To improve the efficacy of conventional radiation therapy and reduce the cytotoxicity of healthy tissue, High-Dose Rate brachytherapy (HDR) may be used as a stand-alone treatment or after surgery to prevent the recurrence of cancer cells. To design and provide studies of these brachytherapy beads, a model was developed by coupling a chelating agent DOTA onto the surface of macrobeads that coordinated to Europium (III) in efforts to mimic the radiolabeling with a radioactive metal. These brachytherapy beads will be used to conduct in vitro studies in the treatment of local cancers with massive concentrations of radiation without damaging surrounding healthy tissue.