La première partie de cette thèse est dédiée à la modification de polyélectrolytes pour former des films de multicouche de polyélectrolytes (PEM) ayant des propriétés d’adhésion de protéine et de cellules bien contrôlées et modifiables par étirement. L’acide polyacrylique a été modifié avec des groupes latéraux phosphorylcholine (PC) à des taux de 25 % (PAA-PC) ou avec des chaînes oligo(éthylène oxyde) terminées par la biotine : (EO)nBiotine (n = 0, 3, 9 et 18) avec de taux de modification de 1, 5, 10 ou 25 %. Des PEM incorporant ces polymères lient spécifiquement la streptavidine et repoussent tout autre protéine. Les propriétés d’adsorption et la sélectivité de ces PEM ont été mesurées par microbalance à quartz. Sur un substrat de PDMS étirables, on a construit des PEM terminés par un PAA portant des RGD recouvert par deux couches contenant PAA-PC. Au repos, seuls les PC sont exposés et inhibent l’adhésion cellulaire ; sous étirement, les groupes RGD sous-jacents sont exposés et déclenchent l’adhésion de fibroblastes.La deuxième partie est consacrée à l‘étude d’acide polyméthacrylique modifié hydrophobiquement avec des chaînes alkyle liées par des esters à la chaîne principale. 3 chaînes différentes ont été greffées : -C12H25 ; -C18H35 et C4H8-OOC- C11H23 avec des taux de 1, 5 and 10 %. Ces polymères sont associatifs et forment des hydrogels dans des tampons physiologiques pour des taux de modifications de 5% et des concentrations supérieures à 4% en poids. Ces gels ont été caractérisés par des mesures rhéologiques. Leur incubation avec des lipases provoque une baisse de leur viscosité, interprétable par une coupure des esters. Quand les gels faits à partir du PAA-C12 sont incubés avec une culture de Pseudomonas aeruginosa, la viscosité baisse également, ce qui montre que les chaînes sont également coupées in vivo. / The first part of this thesis is dedicated to the modification of polyelectrolytes to form polyelectrolyte films with controlled and stretch responsive cell and protein adsorption properties. Poly(acrylic acid) (PAA) was modified with side phosphorylcholine groups (PC) at rates of 25 % or with oligo(ethylene oxide) chains ended by biotin ((EO)nBiotin, (n =0, 3, 9 and 18) at 1, 5, 10 and 25 % modification rates. Polyelectrolytes multilayer films (PEM) containing these polyelectrolytes bind selectively streptavidin but repel all other proteins. The adsorption properties and selectivity were measured by quartz crystal microbalance. On a stretchable PDMS substrate, we have built PEM ended by PAA bearing RGD, covered by two PAA-PC layers on the top. Under rest, only the PC groups are exposed and prevent cell adhesion; when the film is stretched, the underlying RGD groups are exposed, and trigger adhesion of fibroblasts.The second part was consecrated to the study of poly(methacrylic acid) hydrophobically modified with alkyl chains connected through an ester moiety to the main chain. Three different chains were grafted -C12H25; -C18H35 and -C4H8- OOC-C11H23 with a rate of 1, 5 and 10 %. These polymers associate in water and form hydrogels in physiological buffer, for modification rates higher than 5 % and polymer concentrations higher than 4 wt. %. The gels were characterized by rheology. Their incubation with lipases resulted in a decrease of their viscosity, which could be interpreted by the cleavage of the hydrophobic side chains, by rheological tests. When the gels with PAA-C12 were incubated with a culture of Pseudomonas aeruginosa, their viscosity decreased, which shows that alkyle chains are also cleaved in vivo.

Invasion and metastasis of cancer is the leading cause of increased mortality. In addition, haematological malignancies (leukaemia and lymphoma) are a significant cause of morbidity and mortality in both children and adults. Therefore, new treatments which will inhibit cancer progression are required. Integrin adhesion receptors, particularly the RGD-binding integrin subfamily comprising αvβ3, αvβ5, αvβ6, αvβ8, αllbβ3, α5β1, α8β1 and αvβ1 are related to progress and spread of cancer and poor prognosis. Because of the importance of integrin biology in the regulation of cancer dissemination, the integrin receptors are being utilised as targets to regulate cancer progression. The goal of this study was to develop a dual αvβ3/ αIIbβ3 expressing model for testing integrin antagonists. Expression of αv, αIIb, and β3 integrin subunits was characterised using immunofluorescence and flow cytometry in a panel of cell lines. After characterising the expression of αv, αIIb and β3 integrin subunits in inducible and natural expression models (K562 and MCF-7 cells respectively), functional tests for cellular adhesion, detachment and migration were determined. Phorbol 12-myristate 13-acetate (PMA)-treated K562 cells showed increased adhesion on fibrinogen compared to untreated cells. Adhesion of cancer cells (K562 ± PMA and MCF-7) to fibrinogen was inhibited and detachment was induced by the known β3 antagonists, cRGDfV and GR104453. Migration of cancer cells (K562 without PMA and MCF-7) was inhibited by combination of the known β3 antagonists. A panel of 12 novel small molecules developed in the ICT was investigated for cytotoxicity and activity in the validated function assays. ICT9055 was the most potent antagonist in inhibition of cell adhesion, migration, and inducing cell detachment. The data presented in this thesis had selected models and assays for evaluating small molecule integrin antagonists and identified ICT9055 as a promising molecule to develop for further preclinical evaluation. / The Libyan Embassy; Omer Al Mukhtar University, Faculty of Medical Technology, Derna, Libya.

No description available.

京都大学 / 新制・課程博士 / 博士(医学) / 甲第23806号 / 医博第4852号 / 新制||医||1058(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 森信 暁雄, 教授 上野 英樹, 教授 椛島 健治 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Yes / The integrins are a family of 24 heterodimeric transmembrane cell surface receptors. Involvement in cell attachment to the extracellular matrix, motility, and proliferation identifies integrins as therapeutic targets in cancer and associated conditions; thrombosis, angiogenesis and osteoporosis. The most reported strategy for drug development is synthesis of an agent that is highly selective for a single integrin receptor. However, the ability of cancer cells to change their integrin repertoire in response to drug treatment renders this approach vulnerable to the development of resistance and paradoxical promotion of tumor growth. Here, we review progress towards development of antagonists targeting two or more members of the RGD-binding integrins, notably αvβ3, αvβ5, αvβ6, αvβ8, α5β1, and αIIbβ3, as anticancer therapeutics.

Yes / The Arg-Gly-Asp (RGD)-binding family of integrin receptors, and notably the β3 subfamily, are key to multiple physiological processes involved in tissue development, cancer proliferation, and metastatic dissemination. While there is compelling preclinical evidence that both αvβ3 and αIIbβ3 are important anticancer targets, most integrin antagonists developed to target the β3 integrins are highly selective for αvβ3 or αIIbβ3. We report the design, synthesis, and biological evaluation of a new structural class of ligand-mimetic β3 integrin antagonist. These new antagonists combine a high activity against αvβ3 with a moderate affinity for αIIbβ3, providing the first evidence for a new approach to integrin targeting in cancer. / This work was supported by the EPSRC (RCUK Academic Fellowship and Grant EP/H002626/1 to H.M.S.) and Prostate Cancer UK (Pilot Grant PA10-01). F.O.F.O.A-S.. was funded by the Public Authority for Applied Education and Training, Kuwait (PhD studentship).

Le RAFT-RGD radiomarqué avec un émetteur β- comme nouvel agent de radiothérapie interne vectorisée. L'intégrine αvβ3 est fortement impliquée en oncogenèse à travers son rôle dans la néoangiogenèse tumorale, dans la prolifération et la survie des cellules cancéreuses et dans le processus métastatique. L'intégrine αvβ3 est exprimée faiblement dans la plupart des tissus. Par contre, elle est fortement exprimée par les cellules endothéliales activées lors de l'angiogenèse et par les cellules de nombreux types de cancers invasifs. Ces caractéristiques font de l'intégrine αvβ3 une excellente cible pour l'imagerie et la thérapie de ces tumeurs. Le RAFT-RGD (Regioselectively Addressable Functionalized Template-(cyclo-[RGDfK])4) est un derivé polypeptidique constitué de quatre peptides cyclo-RGD (spécifiques de l'intégrine αvβ3) fixés sur un groupe porteur RAFT. Le RAFT-RGD cible spécifiquement l'intégrine αvβ3 in vitro et in vivo et permet la détection par imagerie nucléaire ou par fluorescence de tumeurs exprimant αvβ3 sur des modèles précliniques. Le RAFT-RGD un excellent vecteur potentiel pour cibler les tumeurs exprimant αvβ3 et pour y délivrer des traitements, que ce soit des molécules de chimiothérapie ou des radionucléides de thérapie. Cette étude est la première à évaluer le potentiel thérapeutique du RAFT-RGD radiomarqué avec un émetteur β- sur un modèle de souris Nude porteuses de tumeurs exprimant l'intégrine αvβ3. Une injection de 37 MBq de 90Y-RAFT-RGD ou de 177Lu-RAFT-RGD permet de ralentir significativement la croissance de tumeurs exprimant l'intégrine αvβ3 par rapport aux souris contrôles non traitées ou traitées avec la même activité de la molécule de contrôle non spécifique de la cible, le RAFT-RAD. En comparaison, une injection de 30 MBq de 90Y-RAFT-RGD ne permet pas de ralentir la croissance de tumeurs n'exprimant pas l'intégrine αvβ3. Le RAFT-RGD présente un bon potentiel pour le traitement de tumeurs exprimant l'intégrine αvβ3 lorsqu'il est radiomarqué avec des émetteurs β-. Mots clés : intégrine αvβ3, RAFT-RGD, ciblage tumoral, radiothérapie interne vectorisée. / Β- emitters radiolabeled RAFT-RGD as new agents for internal targeted radiotherapy. The αvβ3 integrin is known to play an important role in tumor-induced angiogenesis, tumor proliferation, survival and metastasis. Because of its overexpression on neoendothelial cells such as those present in growing tumors, as well as on tumor cells of various origins, αvβ3 integrin is an attractive molecular target for diagnosis and therapy of the rapidly growing and metastatic tumors. A tetrameric RGD-based peptide, regioselectively addressable functionalized template-(cyclo-[RGDfK])4 (RAFT-RGD), specifically targets integrin αvβ3 in vitro and in vivo. RAFT-RGD has been used for tumor imaging and drug targeting. This study is the first to evaluate the therapeutic potential of the β- emitters radiolabeled tetrameric RGD peptide RAFT-RGD in a Nude mouse model of αvβ3-expressing tumors. An injection of 37 MBq of 90Y-RAFT-RGD or 177Lu-RAFT-RGD in mice with αvβ3-positive tumors caused a significant growth delay as compared with mice treated with 37 MBq of 90Y-RAFT-RAD or 177Lu-RAFT-RAD or untreated mice. In comparison, an injection of 30 MBq of 90Y-RAFT-RGD had no efficacy for the treatment of αvβ3-negative tumors. 90Y-RAFT-RGD and 177Lu-RAFT-RGD are potent αvβ3-expressing tumor targeting agents for internal targeted radiotherapy. Keys words : integrin αvβ3, RAFT-RGD, tumour targeting, internal targeted radiotherapy.

A imagem molecular oferece a perspectiva de detectar doenças bem antes de os sintomas surgirem. A vasculatura tumoral é vital no crescimento do tumor e na disseminação de metástases, sendo assim alguns radiofármacos são dirigidos para a angiogênese. O glioma, tumor cerebral de baixa incidência porém alta mortalidade, requer um diagnóstico precoce para favorecimento da abordagem terapêutica. O objetivo desse estudo foi o desenvolvimento de novo radiofármaco para diagnóstico por imagem de glioma, baseado em peptídeos angiogênicos (GX1 e GX1-RGD) marcados com o radioisótopo tecnécio-99m. O desempenho dos conjugados peptídicos mostraram-se bastante parecidos em diversas avaliações. Eles foram radiomarcados com alta pureza radioquímica (>96%) e estáveis em soro até pelo menos 4h. Ambos são hidrofílicos e com baixa ligação às proteínas plasmáticas. A biodistribuição em animais sadios demonstrou alta excreção renal e depuração sanguínea rápida para ambos os radiotraçadores. Nos estudos in vitro, o 99mTc-HYNIC-PEG4-c(GX1) apresentou picos de ligação aos 60 min e o 99mTc-HYNIC-E-[c(RGDfk)-c(GX1)]) aos 120 min, nas células endoteliais HUVEC, usadas como controle, e nas células tumorais das linhagens U87MG e T98G. A captação tumoral nos animais foi mais acentuada para células U87MG, especialmente para o 99mTc-HYNIC-E-[c(RGDfk)-c(GX1)]) (2,87 ± 0,53% DI/g) aos 60 min p.i., com boa visualização em imagens adquiridas por gama-câmara e micro-SPECT/CT. Estudos realizados com os peptídeos conjugados à nanopartículas magnéticas para visualização em ressonância magnética também demonstraram especificidade dos produtos em tecidos tumorais. O desempenho do 99mTc-HYNIC-E-[c(RGDfk)-c(GX1)]) foi superior que o do traçador GX1, quanto à captação no glioma humano, podendo ser considerado como um promissor radiofármaco para diagnóstico de gliomas. / Molecular imaging offers the prospect of detecting diseases well before the symptoms appear. The tumor vasculature is vital in the tumor growth and dissemination of metastasis, thus some radiopharmaceuticals are directed to angiogenesis. The glioma, a brain tumor of low incidence but high mortality, requires an early diagnosis for favoring therapeutic approaches. The aim of this study was the development of a new radiopharmaceutical for imaging diagnosis of glioma, based in angiogenic peptides (GX1 and RGD-GX1) radiolabeled with technetium-99m radioisotope. The peptidic conjugates showed very similar performance in several evaluation. They were radiolabeled with high radiochemical purity (>96%) and are stable in the blood serum at least for four hours. Both are hydrofilic and had minimal binding to plasma protein. The biodistribution in healthy mice at many times, showed high renal excretion and fast blood clearance for both radiotracers. At in vitro studies, the 99mTc-HYNIC-PEG4-c(GX1) exhibit binding peaks at 60 min and the 99mTc-HYNIC-E-[c(RGDfk)-c(GX1)]) at 120 min, at HUVEC endotelial cells, used as control, and at tumor cell lines U87MG and T98G. The animal tumor uptake was more pronounced for U87MG cells, specially for 99mTc-HYNIC-E-[c(RGDfk)-c(GX1)]) (2.87 ± 0.53% DI/g) at 60 min p.i., with good visualization in images acquired with gama-camara and micro-SPECT/CT. Studies performed with peptides conjugate to magnetonanoparticles for MRI visualization also demonstred the peptides specificity in tumor tissue.The 99mTc-HYNIC-E-[c(RGDfk)-c(GX1)]) performance was superior to the GX1 tracer, regarding the glioma uptake, and may be consider as a promisser radiopharmaceutical for glioma diagnosis.

A imagem molecular oferece a perspectiva de detectar doenças bem antes de os sintomas surgirem. A vasculatura tumoral é vital no crescimento do tumor e na disseminação de metástases, sendo assim alguns radiofármacos são dirigidos para a angiogênese. O glioma, tumor cerebral de baixa incidência porém alta mortalidade, requer um diagnóstico precoce para favorecimento da abordagem terapêutica. O objetivo desse estudo foi o desenvolvimento de novo radiofármaco para diagnóstico por imagem de glioma, baseado em peptídeos angiogênicos (GX1 e GX1-RGD) marcados com o radioisótopo tecnécio-99m. O desempenho dos conjugados peptídicos mostraram-se bastante parecidos em diversas avaliações. Eles foram radiomarcados com alta pureza radioquímica (>96%) e estáveis em soro até pelo menos 4h. Ambos são hidrofílicos e com baixa ligação às proteínas plasmáticas. A biodistribuição em animais sadios demonstrou alta excreção renal e depuração sanguínea rápida para ambos os radiotraçadores. Nos estudos in vitro, o 99mTc-HYNIC-PEG4-c(GX1) apresentou picos de ligação aos 60 min e o 99mTc-HYNIC-E-[c(RGDfk)-c(GX1)]) aos 120 min, nas células endoteliais HUVEC, usadas como controle, e nas células tumorais das linhagens U87MG e T98G. A captação tumoral nos animais foi mais acentuada para células U87MG, especialmente para o 99mTc-HYNIC-E-[c(RGDfk)-c(GX1)]) (2,87 ± 0,53% DI/g) aos 60 min p.i., com boa visualização em imagens adquiridas por gama-câmara e micro-SPECT/CT. Estudos realizados com os peptídeos conjugados à nanopartículas magnéticas para visualização em ressonância magnética também demonstraram especificidade dos produtos em tecidos tumorais. O desempenho do 99mTc-HYNIC-E-[c(RGDfk)-c(GX1)]) foi superior que o do traçador GX1, quanto à captação no glioma humano, podendo ser considerado como um promissor radiofármaco para diagnóstico de gliomas. / Molecular imaging offers the prospect of detecting diseases well before the symptoms appear. The tumor vasculature is vital in the tumor growth and dissemination of metastasis, thus some radiopharmaceuticals are directed to angiogenesis. The glioma, a brain tumor of low incidence but high mortality, requires an early diagnosis for favoring therapeutic approaches. The aim of this study was the development of a new radiopharmaceutical for imaging diagnosis of glioma, based in angiogenic peptides (GX1 and RGD-GX1) radiolabeled with technetium-99m radioisotope. The peptidic conjugates showed very similar performance in several evaluation. They were radiolabeled with high radiochemical purity (>96%) and are stable in the blood serum at least for four hours. Both are hydrofilic and had minimal binding to plasma protein. The biodistribution in healthy mice at many times, showed high renal excretion and fast blood clearance for both radiotracers. At in vitro studies, the 99mTc-HYNIC-PEG4-c(GX1) exhibit binding peaks at 60 min and the 99mTc-HYNIC-E-[c(RGDfk)-c(GX1)]) at 120 min, at HUVEC endotelial cells, used as control, and at tumor cell lines U87MG and T98G. The animal tumor uptake was more pronounced for U87MG cells, specially for 99mTc-HYNIC-E-[c(RGDfk)-c(GX1)]) (2.87 ± 0.53% DI/g) at 60 min p.i., with good visualization in images acquired with gama-camara and micro-SPECT/CT. Studies performed with peptides conjugate to magnetonanoparticles for MRI visualization also demonstred the peptides specificity in tumor tissue.The 99mTc-HYNIC-E-[c(RGDfk)-c(GX1)]) performance was superior to the GX1 tracer, regarding the glioma uptake, and may be consider as a promisser radiopharmaceutical for glioma diagnosis.

Ces travaux de thèse portent sur la conception, la synthèse et l'étude biologique de vecteurs peptidiques pour des applications en diagnostic et/ou thérapie du cancer.Nous avons utilisé des châssis cyclodécapeptidiques fonctionnalisés de façon chimiosélective par des éléments de ciblage et des effecteurs. Ces châssis, dotés de quatre ligands c[RGDfK], possèdent une forte affinité pour les récepteurs intégrine avB3 qui sont surexprimés dans de nombreux cancers et par les cellules endothéliales de l'environnement tumoral. Ils sont en revanche peu exprimés par les tissus sain. La présentation multivalente des ligands -RGD- permet également au châssis d'être internalisé par les cellules tumorales.Nous avons donc mis au point des molécules composées du châssis peptidique, de quatre ligands -RGD- pour le ciblage tumoral, et de différents effecteurs pour plusieurs applications. A travers de multiples collaborations, nous avons relié ce vecteur à un agent hautement toxique (cryptophycine), un photosensibilisateur (DHP), un peptide pro-apoptotique (BAX), un complexe de Gallium 68 (pour une étude clinique de phase I pour une application en imagerie TEP). Nous avons également greffé ces châssis présentant quatre motifs -RGD- à des polymères ou à des nanoparticules de silice, tous deux fluorescents.Le projet principal de cette thèse était la conception de vecteurs ciblant deux récepteurs tumoraux de manière simultanée. En plus de cibler l'intégrine avB3, nous avons ciblé le récepteur NRP1 qui est lui aussi surexprimé lors de l'angiogenèse tumorale. Nous avons exploité divers réactions chimiosélectives (oxime, cycloaddition de Huisgen, amidation) pour concevoir des vecteurs fluorescents ciblant l'un des deux récepteurs ou les deux à la fois. Des tests biologiques in vitro et in vivo ont été réalisés. Il s'avère que les composés à double ciblage permettent une très bonne détection de la tumeur, mais non supérieure à des composés à mono ciblage. En revanche, la réponse cellulaire déclenchée par les composés à double ciblage est unique, et totalement différente d'une co-injection. Nous avons plusieurs éléments qui tendent à prouver qu'un complexe NRP1-vecteur-Intégrine se formerait et resterait ancré au niveau de la membrane cellulaire, bloquant son internalisation. / This thesis work is about conception, synthesis and biological activities of peptide vectors for diagnostic and/or therapeutic applications against cancer.We used cyclodecapeptidic scaffolds chemoselectively handled with targeting elements and effectors. Those scaffolds presenting four c[RGDfK] ligands have a strong affinity for integrin avB3 receptors, wich are overexpressed in various cancers and by endothelial cells from the tumor surrounding. They are poorly expressed in healthy tissues. The multivalent presentation of -RGD- motifs higly increases the internalisation of the scaffold by tumor cells. Thus we developed molecules composed by four -RGD- motifs for tumor targeting, and different effectors for various applications. Thanks to multiple collaborations, we linked the vector to a highly cytotoxic compound (cryptophycine), a photosensitiser (DHP), a pro-apoptotic peptide (BAX), a DOTA complex (for 68-Ga complexation, for PET applications). We also grafted the cyclodecapeptide bearing four -RGD- motifs to polymers or silica nanoparticles, both fluorescent.The main project of this thesis was the conception of dual targeting vectors. Our objective was to simultaneously target two receptors overexpressed in the tumor periphery. Beside the targeting of avB3, we decided to target the NRP1 receptor, which is also overexpressed during tumor angiogenesis. We exploited various chemoselective reactions (oxime, huisgen cycloaddition, peptide coupling) to synthesise fluorescent vectors targeting one of the two receptors, or both. In vitro and in vivo biological experiments were realised. We discovered that dual targeting compounds allow a really good tumor detection, but inferior to mono targeting ones. Nevertheless, the cellular answer triggered by dual targeting compounds is totally different from those obtained with other compounds, including co-injection. We found different elements that tend to show that a NRP1-vector-integrin could be formed, and would be blocked inside the cellular membrane, resulting in its internalisation's blocking.