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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Implications de l'adrénomédulline sécrétée par les fibroblastes associés au cancer dans la croissance tumorale / Implications of adrenomedullin secreted by cancer-associated fibroblasts in tumor growth

Benyahia, Zohra 05 December 2016 (has links)
Le cancer du sein est la première cause de mortalité chez la femme par cancer. Différents travaux ont montré l’implication des fibroblastes associés au cancer (CAFs) dans la résistance thérapeutique, ainsi que leur rôle dans le développement de cancer du sein. L’adrénomédulline (AM) joue un rôle crucial dans la croissance des tumeurs. Dans notre étude, nous nous sommes interrogés sur l’apport de l’AM sécrétée par la composante majeure du stroma tumoral les CAFs, dans le développement du cancer du sein. Dans cette étude nous avons montré que les CAFs isolés à partir des tumeurs issues du cancer du sein, présentent une augmentation de l’expression du système d’AM (AM et ses récepteurs) par rapport aux fibroblastes non activés (NHDFs). Nos études dans le modèle d’angiogenèse in vivo montrent que les CAFs sont plus compétents à mettre en place une vascularisation stable et fonctionnelle par rapport aux NHDFs. Cependant, le traitement des souris avec des anticorps anti récepteurs de l’AM (αAMRs) bloque la vascularisation. De plus, les xénogreffes issues du mélange MCF-7/CAFs génèrent des tumeurs plus importantes par rapport aux tumeurs issues de MCF-7 seules ou combinées aux NHDFs. Les souris traitées par voie i.p. avec des αAMRs ou l’antagoniste AM22-52, montrent une inhibition de la croissance tumorale des xénogreffes. Les études immunohistochimiques montrent une vascularisation bien établie chez le groupe MCF-7/CAFs, qui est altérée suite au blocage du système de l’AM.Notre étude montre le rôle important de l’AM sécrétée par les CAFs dans le processus de la tumorigenèse du cancer du sein. / Breast cancer is the leading cause of death among women with cancer. Various studies have shown the involvement of cancer associated fibroblasts (CAFs) in this therapeutic resistance and their role in the development of the tumor. Adrenomedullin (AM) plays a critical role in tumor growth. In our study, we asked about the contribution of AM secreted by the major component of the tumor stroma CAFs in breast cancer development. In this study, we demonstrate that CAFs isolated from tumors derived from breast cancer, showed an increase in the expression of AM (AM and its receptors) compared to non-activated fibroblasts (NHDFs). Our studies in vivo angiogenesis model shows that CAFs are more competent to set-up a stable and functional vasculature compared to NHDFs. However, treatment of mice with antibodies anti AM receptor (αAMRs) blocks vascularization, indicating the role of AM secreted by CAFs in the establishment of neovascularization. Additionally, xenografts from MCF-7 mixture / CAFs generate larger tumors compared to tumors from MCF-7 alone or combined with NHDFs. Mice treated, mice treated by intra-peritoneal (i.p.) injection with αAMRs or antagonist AM22-52, show inhibition of tumor growth of xenografts. Immunohistochemical studies show an established vasculature in the MCF-7 / CAFs group, which is impaired due to the blocking of the AM system.Our study shows the important role of the AM secreted by CAFs in the process of breast cancertumorigenesis. It provides an evidence of the effectiveness of a therapy anti-AM, which will target as one of the most predominant components of breast cancer tumor microenvironment.
2

Impact du dialogue entre microenvironnement intra-tumoral et cellules tumorales dans l'adénocarcinome pancréatique / Impact of intra-tumoral microenvironment and epithelial cells crosstalk in pancreatic adenocarcinoma

Leca, Julie 12 February 2016 (has links)
L’adénocarcinome pancréatique (PDA) présente une résistance accrue aux chimiothérapies. Un concept propose que sa composition cellulaire participe à ce processus en limitant l’accès aux drogues tout en modulant les capacités des cellules tumorales. En effet, les cellules non tumorales, principalement mésenchymateuses (CAFs) et immunitaires, représentent 70% de la masse tumorale et forment le microenvironnement intra-tumoral ou stroma. L’impact du stroma dans le développement et la progression des PDA se trouve être au centre d’un large champ d’investigations cliniques. Notre première étude a porté sur un facteur neurotrophique, Slit2, impliqué dans la guidance axonale est sécrété par les CAFs. Ce dernier induit une augmentation de la migration des cellules de Schwann et des changements morphologiques et quantitatifs des cellules neuronales. Ainsi, les nerfs se retrouvent plus nombreux et de taille plus importante dans la tumeur comparée à un pancréas sain, c’est ce qu’on appelle le remodelage neural. Notre second travail a permis d’identifier un complexe multi-protéique (ANXA6/LRP1/TSP1), associé au trafic vésiculaire, présent uniquement dans le compartiment stromal et plus particulièrement dans les CAFs. Ce complexe est porté par des vésicules extracellulaires et procure un avantage prolifératif et pro-migratoire aux cellules tumorales. Les données obtenues au cours de mon travail de thèse constituent un rationnel fort pour étudier le potentiel thérapeutique des éléments permettant le dialogue entre les différents compartiments de la tumeur dans le but de sensibiliser les cellules tumorales aux chimiothérapies et ainsi d’améliorer la survie des patients. / Pancreatic adenocarcinoma (PDA) is particularly resistant to current therapies. A concept suggests that its cellular composition participates in this process, limiting drugs access and affecting tumor cells behavior. Indeed, non-tumor cells, mainly mesenchymal (including Cancer Associated Fibroblasts, CAFs) and immune cells display over 70% of the tumor mass and form the intra-tumoral microenvironment or stroma. The impact of stroma in PDA development and progression is at the center of many clinical investigations. Firstly, we studied a neurogenic factor, Slit2, implicated in axon guidance pathway and secreted by CAFs. Slit2 increases Schawnn cells migration and morphologic changes of neural cells. Indeed, nerve size and density are increased in a tumor compared to a healthy pancreas, that is called, neural remodeling. Secondly, we worked on a multi-proteic complex (ANXA6/LRP1/TSP1), associated to vesicular trafficking, only expressed in stromal compartment, and mainly in CAFs. This complex is present in extracellular vesicles and confers proliferative and pro-migratory capacities to tumor cells. Data obtained during my thesis constitute an important rationale to target the crosstalk between tumor and stromal compartment, in order to sensitize tumor cells to chemotherapy and improve patient survival.
3

L'influence de l'hypoxie sur l'expression de podoplanine dans les fibroblastes associés au cancer (CAF) et son rôle dans la progression du cancer du sein / The influence of hypoxia on podoplanin expression in cancer-associated fibroblasts (CAF) and its role in the progression of breast cancer

Tejchman, Anna 06 April 2017 (has links)
Le tissu tumoral comprend, outre les cellules cancéreuses, une matrice extra-cellulaire modifiée, les cellules endothéliales des vaisseaux sanguins et lymphatiques, immunes et inflammatoires et des fibroblastes actives associés au cancer (CAFs). La podoplanine (PDPN), glycoprotéine transmembranaire de type mucine, y est exprimée dans les cellules cancéreuses et les CAFs. Elleaidea la métastase comme montré dans le carcinome mammaire envahissant les ganglions lymphatiques. Ce travail montre que PDPN module l’interaction chimiokine/récepteur de l’axe CCL21/CCR7 et dépend de l’hypoxie. La progression tumorale est aidée par le stroma ou les CAFs ont des propriétés particulières par rapport aux fibroblastes normaux. Ils promeuvent la croissance tumorale, le recrutement des précurseurs endothéliaux et l’angiogenèse. Dans le carcinome mammaire, 80% des fibroblastes ont un phénotype CAF. Un modèle de CAFs exprimant la PDPN a permis de démontrer l’implication de CCL21/CCR7 dans la reconnaissance entre cellules tumorales et CAFs via la liaison CCL21/PDPN. Les CAFsPDPN+ secrètent des microARNs qui contrôlent des gènes des cellules cancéreuses. MiR-21 est un régulateur oncogène fondamental, par son action sur le suppresseur de tumeur PTEN. Nous avons analysé l’effet de miR-21, ainsi que de miR-210 et miR-29b sur PDPN dans les fibroblastes en hypoxie pour mimer le microenvironnement intratumoral et mis en évidence les différences biologiques comparativement à la normoxie ainsi que l’effet de la podoplanine sur l’angiogenèse par les cellules endothéliales en colocalization avec les CAFs exprimant la podoplanine et sur l’expression des facteurs proangiogéniques. / Tumor is a pathologic tissue including cancer cells, a modified extracellular matrix, endothelial cells, blood and lymphatic vessels, immune and inflammatory cells and activated fibroblasts called cancer-associated fibroblasts (CAFs). Podoplanin (PDPN), mucin-type transmembrane glycoprotein is expressed in tumor cells and CAFs, helps metastasis. Its role in metastaticprocess has been demonstrated for breast cancer cells into lymph nodes. Here we show that PDPN modulates the CCL21/CCR7 chemokine/receptor axis in a hypoxia-dependent manner. Cancer progression depends on the tumour stroma in which CAFs differ from normal fibroblasts. CAFs promote tumour growth, recruitment of endothelial progenitor cells and angiogenesis. In breast cancer up to 80% of fibroblasts display the CAF phenotype. Here a PDPN expressing model of CAFs made it possible to demonstrate the involvement of CCL21/CCR7 axis in the tumor cell-to-CAF recognition through podoplanin binding of CCL21. PDPN positive CAFs secrete microRNAs, which control gene expression at post-transcriptional level and influence cancer cells. MiR-21 is a key regulator of the oncogenic process, through its downstream target proteins among which the tumor suppressor, PTEN. We analyzed the effect of miR-21, but also oncogenic and hypoxia dependent miRs: miR-210 and miR-29b, on PDPN expression in fibroblasts in conditions mimicking the intra tumor microenvironment, i.e. in hypoxia. This points to crucial differences as compared to normoxia. Moreover we uncover the effect of podoplanin on angiogenesis by endothelial cells colocalizing with CAFs expressing podoplanin and on the expression of most prominent proangiogenic factors.
4

Interplay between cancer cells and cancer-associated fibroblasts in tumor invasion and metastasis formation / Rôle des fibroblastes associés au cancer dans l'invasion tumorale

Atieh, Youmna Marie Lyne 04 July 2017 (has links)
Les carcinomes sont des cancers touchant plusieurs organes du corps humain, notamment les seins, le pancréas, les poumons, l'intestin… et sont issus de la transformation de cellules épithéliales en cellules tumorales. Au cours du développement d'une tumeur, les cellules cancéreuses, contrairement aux cellules normales, acquièrent la capacité de se déplacer dans le corps humain, jusqu'à coloniser des organes voisins. Ces colonies sont appelées métastases. Le processus métastatique est responsable de 90% des décès dans le cadre des carcinomes. Ce processus n'est pas dû à l'action isolée des cellules cancéreuses mais est aussi le résultat d'une coopération entre la tumeur et son voisinage – le microenvironnement tumoral – favorisant la survie et la migration des cellules cancéreuses. Les fibroblastes sont une population cellulaire du microenvironnement tumoral. Il a été démontré que les fibroblastes sont activés à proximité des cellules cancéreuses ; on les qualifie de fibroblastes associés au cancer ou CAFs. Dans des tissus de patients, les tumeurs les plus agressives corrèlent avec un enrichissement en fibroblastes et une matrice plus dense. Mon projet de thèse illustre un nouveau mécanisme de coopération entre CAFs et cellules cancéreuses. Cibler l’action des fibroblastes pourrait ralentir la progression tumorale, voire bloquer la formation de métastases. / Cancer-associated fibroblasts (CAFs) are the most abundant cells of the tumor stroma. Their capacity to contract the matrix and induce invasion of cancer cells has been well-documented. However, it is not clear if CAFs remodel the matrix by other means (degradation, matrix deposition or stiffening). This project demonstrates that CAFs induce cancer cell invasion through assembly of FN into the matrix. CAFs assembled fibronectin (FN) mainly via integrin α5 but integrin αvβ3 was necessary for initial mechanosensing and fibrillar adhesion formation. In the absence of FN, contractility of the matrix by CAFs is preserved. When degradation is impaired, CAFs retain the capacity to induce invasion in a FN-dependent manner. In all cases, the levels of expression of integrin β3 and the amount of assembled FN was directly proportional to the invasion induced by fibroblast populations. Our results highlight FN assembly and integrin β3 as new hallmarks of CAFs. We also noticed that cancer cells migrate towards CAFs suggesting a possible chemotactic response. Using Dunn’s chemotaxis chamber, we found that cancer cells migrate along a gradient of CAF-conditioned media and a gradient of fibronectin. Finally, orthotopic injections of cancer cells and CAFs in the colon wall of mice revealed that CAFs stimulate metastasis of cancer cells to the liver. In conclusion, our data show that CAFs promote cancer cell invasion by depositing fibronectin that can guide cancer cells favoring metastasis formation.
5

Comparing Class a Compressed Air Foam Systems (CAFS) Against Plain Water Suppression in Live Fire Gas Cooling Experiments for Interior Structural Firefighting

Mitchell, Sean Carter 01 June 2013 (has links) (PDF)
Wildland fire services have successfully integrated compressed air foam systems (CAFS) into their fire suppression arsenal over the last few decades to effectively increase the firefighting ability of water. Many urban fire departments have done the same, but far more still rely on plain water to extinguish Class A fires. Many claims have been made about the advantages and disadvantages of firefighting foams, but only limited research has been conducted on the subject to date. Fire departments need more information, beyond that provided by foam suppliers and CAFS equipment manufacturers, to make an independent decision on whether or not to adopt the technology. This thesis is part of a larger project sponsored by the United States Department of Homeland Security Assistance to Firefighter Grant Program (grant ID: EMW-2010-FP-01369) to evaluate the capabilities and limitations of compressed air foam systems (CAFS) for use in structural firefighting applications. Large-scale tests comparing water and foam suppression, which includes aspirated foam and CAFS, in a variety of scenarios were performed to measure the ability of the hose streams to reduce the temperature of a hot gas layer within a structure. These temperature reductions were recorded with thermocouples and are analyzed to determine which suppression agent has a superior gas cooling ability.
6

Targeting Cancer-Associated Fibroblasts: New Opportunity for Therapeutic Intervention in Cutaneous Melanoma

Yang, Kun 04 September 2018 (has links)
No description available.
7

Targeting Sphingosine Kinase 2 as a Treatment for Cholangiocarcinoma

Stillman, Anthony D 01 January 2019 (has links)
Cholangiocarcinoma (CCA) has a high mortality rate and its occurrence is rising. This increase prompts the need for improved CCA treatments. Studies have suggested that CCA is highly reliant on the sphingosine-1-phosphate-receptor-2 (S1PR2) and sphingosine kinase 2 (SphK2). Recently, a competitive SphK2 inhibitor, ABC294640, has been approved for clinical trial. ABC294640 has the potential to treat CCA, which is support by a phase I clinical study that was able to temporarily treat a patient suffering from metastasized CCA with ABC294640. To determine the viability of ABC294640 as a treatment for CCA, this study focused on determining the effects of ABC294640 on rat CCA cell lines. We found that ABC294640 inhibited the growth and migration of CCA and CAFs cells. The growth and count of 3-D organotypic co-culture of CCA and CAFs, which forms the “duct-like” structures, were reduced by ABC294640. The potential of inhibiting SphK2 as a treatment for CCA is supported by our finding of increased expression of S1PR2 and SphK2 in CCA patient liver samples. In conclusion, ABC294640 represents a potential therapeutic agent for CCA.
8

PHARMACOLOGICAL TARGETING OF FGFR IN METASTATIC BREAST CANCER IS AUGMENTED BY DNMT1 INHIBITION

Mitchell G Ayers (18990533) 02 August 2024 (has links)
<p dir="ltr">Metastatic breast cancer (BC) remains a dauting therapeutic challenge due to the heterogeneity and cellular plasticity that exists. Because of these, BC resistance to targeted therapies and immune checkpoint blockade (ICB) present major challenges in the clinical setting. As a result, incomplete clearance of BC during a therapeutic regimen can lead to the persistence of minimal residual disease (MRD) which greatly contributes to tumor relapse. Here we develop a powerful in vivo model of lung metastasis in which we can achieve robust pulmonary tumor regression in response to the fibroblast growth factor receptor (FGFR) inhibitor, pemigatinib.</p><p dir="ltr">To enhance the efficacy of ICB, tumors must first be converted from an immune “cold” environment to an immune “hot” environment. Using our in vivo model of lung metastasis, we demonstrated that pemigatinib can significantly increase the presence of infiltrating T-cells into the lungs while suppressing the presence of MDSCs both locally in the lungs and systemically. Taken together, pemigatinib is an ideal candidate to prime these immune “cold” tumors for combination with ICB.</p><p dir="ltr">Upon establishment of MRD by pemigatinib in our in vivo model we observe upregulation of an alternate growth factor receptor, platelet-derived growth factor receptor (PDGFR). Functionally, upon FGFR inhibition, there is increased response to pulmonary fibroblast derived PDGF ligand, fueling survival of MRD. We demonstrated that knockdown of PDGFR significantly delayed tumor growth reinitiation in an in vitro 3D culture following pemigatinib as well as delayed tumor relapse in our pulmonary metastasis model.</p><p dir="ltr">To limit cellular plasticity and reduce survival of MRD, we propose a novel dual-targeted approach utilizing pemigatinib, in conjunction with inhibition of DNMT1 using the reversible inhibitor GSK3484862. We used our in vivo model of lung metastasis after treatment with pemigatinib as a model of cellular plasticity to targeted therapy. This combination therapy prevented growth factor plasticity and delayed tumor recurrence. Through prevention of PDGFR upregulation induced by pemigatinib.</p><p dir="ltr">In the present dissertation works, our study demonstrates pemigatinib’s robust ability to increase infiltrating T-cells in addition to its strong antitumor effects on pulmonary tumors. Despite the robust effects of pemigatinib, acquired mechanism of resistance through upregulation of PDGFR allows survival of MRD and are supported by PDGF secreting fibroblasts. Using an approach of limiting cellular plasticity through DNA methylation inhibition combined with pemigatinib, we achieved a more durable therapeutic response. Our findings underscore the significance of understanding adaptive responses to targeted therapies and provide a tangible therapeutic strategy to prolong treatment response in metastatic breast cancer.</p>
9

Mesoporous Silica Nanoparticles Targeting Tumor Microenvironment as a Tool for Breast Cancer Treatment

Trigo Lameirinhas, Ana Catarina 13 September 2025 (has links)
[ES] La mayoría de las terapias contra el cáncer de mama que se utilizan actualmente en la práctica clínica se centran en atacar las células tumorales. Sin embargo, los nuevos avances en el campo de la inmunología han resaltado el papel principal del microambiente tumoral en la modulación tumoral. Específicamente, los fibroblastos asociados al cáncer desempeñan un papel importante en la progresión tumoral, la modulación de la inmunidad tumoral y la resistencia a la terapia. Por ello, esta tesis doctoral titulada "Nanopartículas de sílice mesoporosas dirigidas al microambiente tumoral como herramienta para el tratamiento del cáncer de mama" se centra en el diseño de un nanodispositivo dirigido a los fibroblastos asociados al cáncer y en la evaluación de su potencial como nueva estrategia terapéutica para el tratamiento del cáncer de mama. Se diseñó y sintetizó una nanopartícula utilizando nanopartículas mesoporosas de sílice como soporte, cargadas con doxorrubicina y funcionalizadas con un péptido ligando de FAP-¿ (NP-FAP-DOX). La caracterización de NP-FAP-DOX mostró una liberación controlada de la carga y un perfil no tóxico in vitro. Los estudios in vitro evaluaron la eficacia de las nanopartículas para dirigirse a FAP-¿, la citotoxicidad celular y la penetrabilidad tumoral en las líneas celulares de cáncer de mama, en los fibroblastos asociados al cáncer derivados de biopsias de pacientes con cáncer de mama triple negativo y en los organoides derivados de pacientes con cáncer de mama. Estos estudios demostraron que NP-FAP-DOX se dirigió eficazmente y produjo un efecto citotóxico en células de cáncer de mama con expresión positiva de FAP-¿, así como en fibroblastos asociados al cáncer. Además, la NP-FAP-DOX presentó una buena eficiencia de penetración en los organoides derivados de paciente, manteniendo así la acción dirigida y el efecto citotóxico en este modelo tridimensional. Finalmente, se evaluó la eficacia de NP-FAP-DOX in vivo en un modelo murino de cáncer de mama triple negativo. La NP-FAP-DOX mostró una buena capacidad para atacar tumores y una administración eficaz de fármacos, lo que dio como resultado un efecto antitumoral in vivo. Además, el tratamiento in vivo con NP-FAP-DOX se dirigió eficazmente a los fibroblastos asociados al cáncer y los eliminó, lo que llevó a la remodulación del microambiente tumoral y a la activación de la respuesta inmunitaria del tumor. Específicamente, este tratamiento promovió la infiltración de linfocitos, aumentó el porcentaje de células asesinas naturales y disminuyó los macrófagos M2, lo que llevó a un aumento de la proporción M1/M2 en los tumores. Además, las nanopartículas mejoraron el perfil terapéutico y de seguridad del fármaco libre, previniendo la toxicidad cardíaca y sistémica inducida por doxorrubicina. Con todo, estos resultados demostraron el potencial de los nanodispositivos diseñados como un nuevo sistema de administración de fármacos dirigido para el tratamiento del cáncer de mama. Estas nanopartículas pueden mejorar la eficacia de la administración de fármacos, superar los efectos secundarios adversos y mejorar la eficacia de la terapia mediante la modulación del microambiente tumoral. / [CA] La majoria de les teràpies contra el càncer de mama que s'utilitzen actualment en la pràctica clínica, es centren en atacar les cèl·lules tumorals. Tanmateix, els nous avanços en el camp de la immunologia han ressaltat el paper principal del microambient tumoral en la modulació tumoral. Específicament, els fibroblasts associats al càncer tenen un paper important en la progressió tumoral, la modulació de la immunitat tumoral i la resistència a teràpia. Per això, aquesta tesi doctoral titulada "Nanopartícules de sílice mesoporoses dirigides al microambient tumoral com a ferramenta per al tractament del càncer de mama" es centra en el disseny d'un nanodispositiu dirigit als fibroblasts associats al càncer i en l'avaluació del seu potencial com a nova estratègia terapèutica per al tractament del càncer de mama. Es va dissenyar i sintetitzar una nanopartícula utilitzant nanopartícules mesoporoses de sílice com a suport, carregades amb doxorubicina i funcionalitzades amb un pèptid lligand de FAP-¿ (NP-FAP-DOX). La caracterització de NP-FAP-DOX va mostrar un alliberament controlat de la càrrega i un perfil no tòxic in vitro. Els estudis in vitro van avaluar la eficàcia de les nanopartícules en l'acció dirigida a FAP-¿, la citotoxicitat cel·lular i la penetrabilitat tumoral en les línies cel·lulars de càncer de mama, en els fibroblasts associats al càncer derivats de biòpsies de pacients amb càncer de mama triple negatiu i en els organoides derivats de pacients amb càncer de mama. Aquests estudis van demostrar que NP-FAP-DOX es dirigia eficaçment i produïa un efecte citotòxic en les cèl·lules de càncer de mama amb expressió positiva de FAP-¿, així com en fibroblasts associats al càncer. A més, la NP-FAP-DOX va presentar una bona eficiència de penetració en els organoides derivats de pacient, mantenint així l'acció dirigida i l'efecte citotòxic en aquest model tridimensional. Finalment, es va avaluar la eficàcia de NP-FAP-DOX in vivo en un model murí de càncer de mama triple negatiu. La NP-FAP-DOX va mostrar una bona capacitat per a atacar tumors i una administració eficaç de fàrmacs, el que va donar com a resultat un efecte antitumoral in vivo. Addicionalment, el tractament in vivo amb NP-FAP-DOX es va dirigir eficaçment als fibroblasts associats al càncer generant la seua depleció i així, la remodelació del microambient tumoral i l'activació de la resposta immunitària del tumor. Específicament, aquest tractament va promoure la infiltració de limfòcits, va augmentar el percentatge de cèl·lules citocides naturals i va disminuir els macròfags M2, el que va conduir a un augment en la proporció M1/M2 en els tumors. A més, les nanopartícules van millorar el perfil terapèutic i de seguretat del fàrmac lliure, prevenint la toxicitat cardíaca i sistèmica induïda per la doxorubicina. Amb tot, aquests resultats demostraren el potencial dels nanodispositius dissenyats com un nou sistema d'administració de fàrmacs dirigits per al tractament del càncer de mama. Aquestes nanopartícules poden millorar l'eficàcia de l'administració de fàrmacs, reduir els efectes secundaris adversos i millorar l'eficàcia de la teràpia mitjançant la modulació del microambient tumoral. / [EN] Most of the breast cancer therapies currently used in the clinical practice are focused on targeting tumor cells. Nevertheless, new advances in the immunology field uncovered the main role of the tumor microenvironment in tumor modulation. Specifically, cancer-associated fibroblasts play an important role in tumor progression, tumor immunity modulation, and therapy resistance. Hence, this Ph.D. thesis entitled "Mesoporous silica nanoparticles targeting tumor microenvironment as a tool for breast cancer treatment" is focused on the design of a nanodevice targeting cancer-associated fibroblasts and on the evaluation of its potential as a new therapeutic strategy for breast cancer treatment. A nanoparticle was designed and synthesized using mesoporous silica nanoparticles as support, loaded with doxorubicin, and functionalized with a FAP-¿ ligand peptide (NP-FAP-DOX). NP-FAP-DOX's characterization showed controlled cargo release and an in vitro nontoxic profile. The in vitro studies evaluated the nanoparticle efficacy to target FAP-¿, cellular cytotoxicity, and tumor penetration in breast cancer cell lines, cancer-associated fibroblasts derived from triple-negative breast cancer patient biopsies, and breast cancer patient-derived organoids. These studies probed that the NP-FAP-DOX efficiently targeted and produced a cytotoxic effect in breast cancer cells with FAP-¿ positive expression as well as in cancer-associated fibroblasts. Moreover, the NP-FAP-DOX presented good penetration efficiency in patient-derived organoids, while maintaining the targeting and cytotoxic effect in this 3D model. Finally, the NP-FAP-DOX's in vivo efficacy was evaluated in a murine triple-negative breast cancer model. The NP-FAP-DOX showed a tumor-targeting ability and effective drug delivery, resulting in an in vivo antitumoral effect. Moreover, the NP-FAP-DOX in vivo treatment efficiently targeted and depleted cancer-associated fibroblasts, leading to tumor microenvironment re-modulation and activation of tumor immune response. Specifically, this treatment promoted lymphocyte infiltration, increased the percentage of natural killer cells, and decreased the M2-like macrophages leading to an increased M1/M2 ratio in tumors. Besides, the nanoparticles improved the therapeutic and safety profile of the free drug, preventing doxorubicin-induced cardio and systemic toxicity. Overall, these results demonstrated the potential of the designed nanodevices as a new targeted drug delivery system for breast cancer treatment. These nanoparticles can improve drug delivery efficacy, overcome adverse side effects, and enhance therapy efficacy through the modulation of the tumor microenvironment. / Trigo Lameirinhas, AC. (2024). Mesoporous Silica Nanoparticles Targeting Tumor Microenvironment as a Tool for Breast Cancer Treatment [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/210630

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