No description available.

La bonne prise en charge des tumeurs repose sur un diagnostic précoce et une thérapie ciblée efficace. Nousétudions dans ce projet trois outils théranostiques, différents par leur origine et par leurs caractéristiques, afin dedémontrer leur intérêt pour l’imagerie et la thérapie des tumeurs.Le premier est un outil biologique, les cellules souches mésenchymateuses humaines connues pour leur tropismenaturel pour les sites inflammatoires et/ou hypoxiques, qui devrait donc leur permettre d’atteindre les tumeurs.Le deuxième outil consiste en des nanoparticules fonctionnalisées ou non avec un ligand ciblant les cellulestumorales, délivrées sous forme de spray dans les poumons. Cette méthode présente l’avantage de développer unoutil peu invasif pouvant être administré chez un patient présentant un cancer du poumon disséminé.Le dernier est un outil synthétique, bien défini structurellement, synthétisable de manière reproductible, de petitetaille, qui, après une administration par voie systémique cible les cellules tumorales primaires ou métastasées.Mes travaux permettent de mettre en évidence que, bien que les cellules souches mésenchymateuses ne soientpas de bons vecteurs pour le diagnostic et pour véhiculer un agent vers la tumeur, elles permettent de normaliserla vascularisation tumorale et de réorganiser les flux sanguins au sein de la tumeur. Ceci présente un éventuelintérêt thérapeutique, bien que complexe à mettre en application, qui pourrait ouvrir la porte à un pré-traitement« normalisateur » de la vascularisation tumorale.L’étude sur les nanovecteurs aérosolisés montre qu’ils peuvent être utiles, non seulement pour le ciblage tumoralpassif mais également pour le ciblage actif lorsqu’ils sont greffés avec un anticorps monoclonal spécifique descellules tumorales puisqu’ils permettent de détecter des nodules tumoraux répartis dans les poumons. De plus, leCetuximab utilisé ici comme agent de ciblage acquiert des propriétés nouvelles lorsqu’il est présenté sur desnanoparticules et permettrait de diminuer la résistance des cellules tumorales au traitement.Enfin, la petite molécule synthsétique PoroCombo que nous développons à partir de nos travaux antérieurs sur levecteur RAFT-RGD semble être la plus appropriée des trois pour délivrer une drogue dans le cytoplasme descellules après injection par voie systémique. De plus, cette molécule présente une triple activité anti-tumoraleavec l’induction de la mort cellulaire ainsi qu’un effet anti-angiogénique et le possible déclenchement d’uneréaction immunitaire anti-tumorale.Les trois « biovecteurs » étudiés ouvrent la porte vers un grand nombre d’applications permettant d’améliorer laprise en charge des tumeurs. / A good tumor treatment relies on an early diagnosis and an efficient targeted therapy.Three theranostic tools are studied, each one having a different origin and different properties, in order to showtheir interest for tumor’s imaging and therapy.The first tool is a biologic one, human mesenchymal stem cells (MSC) having a natural tropism towardinflammatory and/or hypoxic sites, which should permit them to reach tumors.The second one is nanoparticles, functionnalized or not with an antibody targeting tumor cells, delivered by alung spray. By this method we develop a non-invasive tool to treat patients with a disseminated lung tumor.The last one is a synthetic small sized theranostic tool with a reproducible synthesis, which, after a systemicadministration, targets primary and metastatic tumor cells.By my work, I show that even if MSC are not good vectors for diagnosis and delivery of therapeutic agents tothe tumors’ sites, they normalize tumors’ vessels, improving blood flow inside the tumor. This property presentsa real therapeutic interest, by pre-treating tumors before using chemotherapy.The study of aerosolized nanovectors reveals their interest for passive tumor targeting and for an active onewhen grafted with a specific monoclonal antibody as they permit the detection of tumor nodules disseminated inthe lungs.More, the targeting agent Cetuximab acquires new properties when grafted on nanoparticles permitting todecrease tumor cells resistance to the treatment.Finally, the small synthetic molecule PoroCombo developed from our previous work on RAFT-RGD vectors,seems to be the most appropriated to deliver a molecule in the cell’s cytoplasm after a systemic administration.This molecule has three anti-tumor activities by inducing cell death, by inducing anti-angiogenic impact and bytriggering anti-tumor immune reaction.The three studied “biovectors” reveal large applications to improve tumors’ treatment.Key words:

Les protéines Sémaphorines et leurs récepteurs Plexines jouent un rôle primordial dans le réseau de signalisation cellulaire. Initialement découvertes pour leur rôle dans le guidage axonal, il fut rapidement mis en lumière qu'elles étaient également impliquées dans le développement du système cardiovasculaire, dans la tumorigénèse et le fonctionnement du système immunitaire, démontrant les multiples facettes de ces protéines. Parmi ces couples de ligands et de récepteurs, la Sémaphorine 3E et son récepteur Plexine D1 représentent des cibles d'intérêt pour les thérapies anti-cancéreuses. La Sémaphorine 3E est surexprimée dans de nombreux cancers et son expression est corrélée à la dissémination métastatique et à la progression tumorale. Ces travaux de thèse ont donc consisté en la caractérisation de ce couple en temps que nouvelle cible anti-tumorale et le développement d'une thérapie ciblée qui a montré des effets prometteurs dans les études pré-cliniques en combinaison avec d'autres thérapies innovantes / The Semaphorin proteins and their receptors Plexins play a primordial role in the cell signaling network. Initially discovered for their role in axonal guidance, it was soon identified that they also are implied in cardiovascular system development, tumorigenesis and immune system functioning, demonstrating the multiple facets of these proteins. Among these pairs of ligands and receptors, Semaphorin 3E and its receptor Plexin D1 represent targets of interest for anticancer therapies. Semaphorin 3E is overexpressed in many cancers and its expression is correlated with metastatic dissemination and tumor progression. This work consisted in characterizing Sema3E/PlxnD1 as new anti-tumor target and developing a targeted therapy. Combination between this therapy and other innovative drugs provided promising results in preclinical studies

The goal of this dissertation was to examine the realized value of targeted therapies in routine care and to identify opportunities for improving the return on medical spending for these technologies. Chapter 1 investigated the value of targeted therapies in lung cancer patients who were treated in routine care. This observational, claims-based analysis used propensity score, and instrumental variable methods, combined with a Kaplan Meier Sample Average estimator to calculate lifetime costs and life expectancy. An incremental comparison showed that the realized value of targeted therapies in routine care was unfavorable relative to chemotherapy treatment. Subgroup analyses revealed that initial erlotinib therapy yielded effectiveness results that are substantially lower than efficacy survival outcomes in molecularly guided trials. Our results indicated that in routine care, chemotherapy was the most cost effective strategy. The unexpectedly low outcomes with first-line erlotinib suggested that some of the value of this treatment was not being realized in practice. Chapter 2 examined the practice patterns of targeted therapies and utilization of predictive biomarker testing in routine care to better understand the observed gaps between trial-based and `real-world' outcomes with these agents. In our nationally representative cohort of lung cancer patients, we found that the vast majority of patients did not undergo molecular testing to inform first-line therapy. Our prediction models for biomarker screening and first-line treatment suggested that phenotypic enrichment criteria guided selection for testing and initiation of erlotinib therapy. Since clinical characteristics do not adequately discriminate between mutation positive and wild type tumors, these practices signal the need for wider dissemination of biomarker screening to accurately target patients towards improving therapeutic gains with erlotinib. Chapter 3 assessed the cost-effectiveness of multiplexed predictive biomarker screening to inform treatment decisions in lung cancer patients. Using a micro-simulation model to evaluate the incremental value of molecularly guided therapy compared to chemotherapy in unselected patients, we found that personalized therapy is a cost effective strategy. Our results indicated that better value of targeted therapies in lung cancer is achievable through molecularly guided treatment.

京都大学 / 0048 / 新制・論文博士 / 博士(農学) / 乙第12879号 / 論農博第2806号 / 新制||農||1028(附属図書館) / 学位論文||H26||N4878(農学部図書室) / 31597 / (主査)教授 植田 和光, 教授 植田 充美, 教授 矢﨑 一史 / 学位規則第4条第2項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

No description available.

Entzündliche Prozesse stellen einen zentralen Aspekt der Karzinogenese dar und können sowohl zur Induktion als auch zum Progress von Tumoren beitragen. Der NF-kB-Signalweg ist einer der wichtigsten Signaltransduktionswege der In- flammation und Tumorpromotion, was ihn zur plausiblen Zielstruktur für die pros- pektive klinische Tumortherapie machen könnte. In der vorliegenden Arbeit wur- den die Eigenschaften von vier unterschiedlich targetierenden NF-kB-pathway- Inhibitoren – Cortisol, MLN4924, QNZ und TPCA1 – auf die Inflammation, Zell- proliferation und proapoptotische Sensitivierung am in vitro Modell des HNSCC untersucht. Es konnte gezeigt werden, dass die spezifische Auswahl des Inhi- bitors bzw. seines targets entscheidend für den wirkungsvollen Einsatz dieser Wirkstoffgruppe in der antiproliferativen Therapie des HNSCC zu sein scheint. Beispielsweise vermittelte MLN4924 die Freisetzung von IL-8. Cortisol bewirkte die Resistenz der FasL-induzierten Apoptose von HNSCC-Zellen. QNZ wirkte in einigen Zelllinien antiproliferativ und sensitivierend für den FasL-induzierten Zell- tod, beeinflusste jedoch in diesem Zusammenhang kontraproduktiv die IL-8-Sek- retion. Dies disqualifizierte diese Wirkstoffe für die Anwendung in der Therapie von Kopf-Hals-Tumoren. Dahingegen qualifizierte sich TPCA-1 aufgrund folgen- der Eigenschaften als geeigneter Wirkstoff für den prospektiven klinischen Ein- satz: 1) TPCA-1 wirkte antiproliferativ, 2) hemmte die TNF-a-induzierte Inflammation, 3) regulierte die IL-8-Expression herab, 4) wirkte sensitivierend für den TNF-a-induzierten Zelltod, 5) interferierte kaum mit der FasL-vermittelten Apoptose und 6) induzierte Apoptose. / Inflammatory processes represent a central aspect of carcinogenesis and may contribute to both tumour induction and progression. The NF-kB signalling pathway is one of the most important signal transduction pathways in inflammation and tumour promotion, which could make it a plausible target for prospective clinical tumour therapy. In the present study, the properties of four different targeting NF-kB pathway inhibitors - cortisol, MLN4924, QNZ and TPCA1 - on inflammation, cell proliferation and proapoptotic sensitivity were investigated in an in vitro model of HNSCC. It was shown that the specific selection of the inhi- bitor or its target seems to be crucial for the effective use of this group of drugs in the antiproliferative therapy of HNSCC. For example, MLN4924 mediated the release of IL-8, and cortisol induced the resistance of FasL-induced apoptosis of HNSCC cells. QNZ had an antiproliferative effect in some cell lines and was sensitive to FasL-induced cell death, but counteracted IL-8 secretion in this context. This disqualified these agents for use in the therapy of head and neck tumours. In contrast, TPCA-1 qualified as a suitable agent for prospective clinical use due to the following properties: 1) TPCA-1 had an antiproliferative effect, 2) inhibited TNF-a-induced inflammation, 3) down-regulated IL-8 expression, 4) was sensitive to TNF-a-induced cell death, 5) hardly interfered with FasL-mediated apoptosis, and 6) induced apoptosis.

Histiocytic sarcoma (HS) is an exceptionally rare malignant neoplasm derived from dendritic cells and histiocytes, with no available effective treatment options. Akt signaling and proteasome dysfunction have been implicated in the pathogenesis of the disease, both in humans and dogs. Our work aims to investigate the importance of the Akt signaling pathway and evaluate the potential of Akt-targeted therapy in a canine model of histiocytic sarcoma. We demonstrated Akt signaling to be active in 9 out of 10 canine HS tumor samples, regardless the presence of PTEN. Moreover, the Akt signaling pathway appears to be constitutively active in DH82 cells — a cell line model of canine HS, when compared to control canine dendritic cells. Pharmacologic Akt inhibition resulted in significant decrease in Akt S473 phosphorylation, GSK-3β S9 phosphorylation, Akt activity, cell viability, increased apoptosis, and resulted in sensitization to proteasome inhibition-depended cell death in a synergistic manner. Proteasome inhibition using carfilzomib, an irreversible proteasome inhibitor, induced dose-depended/caspase-3 independent cell death, at clinically relevant drug concentrations. The therapeutic effect of Akt inhibition was validated in vivo using a DH82 xenograft murine model. Akt inhibition lead to reduced tumor growth, prolonged overall survival, and ameliorated splenomegaly, but not affected the lung metastasis. Moreover, the therapeutic effect of Akt inhibition was potentiated in combination with carfilzomib. In conclusion, targeting Akt signaling may represent an attractive potential therapeutic target for the HS. Future studies are required to examine the clinical efficacy of Akt-targeted therapy in dogs with HS using novel selective Akt inhibitors. / Ph. D. / Histiocytic sarcoma (HS) is an exceptionally rare cancer of the immune system, with no effective treatment options available. Canine histiocytic sarcoma (cHS) is an aggressive tumor of the same cellular lineage, identified at increased relative frequency in specific dog breeds, with significant translational value. Akt signaling and proteasome dysfunction have been implicated in the pathogenesis of the disease, both in humans and dogs. Our study aims to investigate the importance of the Akt signaling pathway in the dog model of the disease and evaluate the potential of Akt-targeted therapy in a translational of histiocytic sarcoma. The work presented here demonstrates that Akt signaling appears aberrantly and constitutively activated in the canine model of HS. Importantly, Akt inhibition significantly reduced the tumor growth and prolonged the overall survival of the experimental animals. Moreover, Akt inhibition potentiated the anti-cancer activities of other anticancer drugs. Collectively, these findings provide an attractive therapeutic approach for the treatment of HS.

Affibody molecules are a promising class of scaffold-based targeting proteins for radionuclide-based imaging and therapy of cancer. This thesis work is based on 5 original research articles (papers I-V), which focus on optimization of molecular design of HER2-binding Affibody variants for high contrast imaging of this predictive biomarker as well as development of Affibody molecules suitable for radionuclide-based targeted therapies.  Papers I and II were dedicated to evaluation of the influence of the macrocyclic chelator DOTA positioning at N-terminus, in the middle of helix-3 and at C terminus of a synthetic Affibody molecule, ZHER2:S1. These synthetic variants were labelled with different radionuclides i.e. 111In and 68Ga to study also the effect of different labels on their biodistribution properties. In paper III a 2-helix variant, Z342min, was developed using native ligation cyclization to cross-link helices one and two resulting in a stable 2-helix scaffold and characterized in vivo. This study was performed with the aim to obtain structure-properties relationship for development of smaller Affibody molecules.   Papers IV and V were devoted to development of therapeutic strategies. In paper IV, a series of peptide based chelators was investigated for labelling of Affibody molecules with 188Re to provide low renal retention. In paper V, a pretargeting approach using peptide nucleic acid was investigated. These studies were performed with the aim to overcome the high renal retention of Affibody molecules when labelled with residualizing therapeutic radionuclides. Otherwise, the particle emitting radiometals could damage the kidneys more than the tumours. The results obtained for anti-HER2 Affibody molecules summarized in this thesis might be of importance for the development of other scaffold protein based targeting agents.

Glioblastoma multiforme (GBM) is the most common and malignant brain tumor in adults, affecting thousands of people worldwide every year, with a life expectancy, post diagnosis of 12 months. Surgery, radiotherapy and chemotherapy together, result in an overall mean survival not exceeding 15 months. Targeted therapeutic agents sorafenib, an oral multi kinase inhibitor, and lapatinib, an epidermal growth factor receptor (EGFR) inhibitor, used in combination have been shown to kill GBM cells be through inhibition of major growth mediating signaling pathways that are frequently over expressed in gliomas, including mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase/ protein kinase B (PI3K/AKT). Sorafenib can restore lapatinib induced cytotoxicity by down regulation of myeloid cell leukaemia-1 (Mcl-1) expression. Prior studies have shown Mcl-1 to play an important role in resistance to lapatinib. Furthermore, data indicated that this drug combination is able to trigger activation of autophagic and apoptotic pathways and induce endoplasmic reticulum (ER) stress response in GBM cells, collectively resulting in cell death. In conclusion, data presented here demonstrates that the combination of sorafenib and lapatinib can kill GBM cells in a greater than additive fashion, through induction of autophagy, apoptotic events (extrinsic and intrinsic) and ER stress.