Tesis: "Preclinical cancer models"

1

Chaffee, Beth K. "Preclinical Modeling of Musculoskeletal Cancer". The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1376844544.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

2

Delgado, San Martin Juan A. "Mathematical models for preclinical heterogeneous cancers". Thesis, University of Aberdeen, 2016. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=230139.

Texto completo

Resumen

Cancer is a deadly, complex disease with 14 million new cases diagnosed every year and the endeavour to develop a cure is a global multidisciplinary effort. The complexity of cancer and the resulting vast volume of data derived from its research necessitates a robust and cutting-edge system of mathematical and statistical modelling. This thesis proposes novel mathematical models of quantification and modelling applied to heterogeneous preclinical cancers, focusing on the translation of animal studies into patients with particular emphasis on tumour stroma. The first section of this thesis (quantification) will present different techniques of extracting and quantifying data from bioanalytical assays. The overall aim will be to present and discuss potential methods of obtaining data regarding tumour volume, stromal morphology, stromal heterogeneity, and oxygen distribution. Firstly, a 3D scanning technique will be discusses. This technique aims to assess tumour volume in mice more precisely than the current favoured method (callipers) and record any cutaneous symptoms as well, with the potential to revolutionise tumour growth analysis. Secondly, a series of image processing methods will be presented which, when applied to tumour histopathology, demonstrate that tumour stromal morphology and its microenvironment play a key role in tumour physiology. Lastly, it will be demonstrated through the integration of in-vitro data from various sources that oxygen and nutrient distribution in tumours is very irregular, creating metabolic niches with distinct physiologies within a single tumour. Tumour volume, oxygen, and stroma are the three aspects central to the successful modelling of tumour drug responses over time. The second section of this thesis (modelling) will feature a mathematical oxygen-driven model - utilising 38 cell lines and 5 patient-derived animal models - that aims to demonstrate the relationship between homogeneous oxygen distribution and preclinical tumour growth. Finally, all concepts discussed will be merged into a computational tumour-stroma model. This cellular automaton (stochastic) model will demonstrate that tumour stroma plays a key role in tumour growth and has both positive (at a molecular level) and negative (at both a molecular and tissue level) effects on cancers. This thesis contains a useful set of algorithms to help visualise, quantify, and understand tissue phenomena in cancer physiology, as well as providing a series of platforms to predict tumour outcome in the preclinical setting with clinical relevance.

Los estilos APA, Harvard, Vancouver, ISO, etc.

3

PEDERZOLI, FILIPPO. "Microbiome and bladder cancer". Doctoral thesis, Università Vita-Salute San Raffaele, 2021. http://hdl.handle.net/20.500.11768/121778.

Texto completo

Resumen

The microbiome has gained increasing momentum in cancer research, as it has become clear that microorganisms residing within our body are involved in mediating the cellular and tissue metabolism in health and disease. In bladder cancer research, there are different microbial communities that may mediate cancer pathobiology and response to therapy: the gut microbiome, the urinary microbiome, the urothelium-bound microbiome. These bacterial communities may mediate the processes of carcinogenesis or recurrence, modify the response to local intravesical therapies or influence the activity of systemic anticancer protocols. Based on these premises, my research project aimed to unveil the urinary and urothelium-bound microbiome in therapy-naïve bladder cancer patients, describing the differently enriched bacterial communities using a sex-based stratification. Compared to healthy controls, I found that the urine of men affected by bladder cancer were enriched in the order Opitutales and subordinate family Opitutaceae, together with the isolated class Acidobacteria-6, while in female patients I found enriched the genus Klebsiella. Notably, the bladder cancer tissue was enriched in the genus Burkholderia in both men and women, when compared to non-neoplastic, paired urothelium biopsies. Then, I also characterized the gut microbiome of bladder cancer patients undergoing neoadjuvant pembrolizumab to understand if the intestinal bacteria may influence the immune-mediated anticancer activity. In this set, I have reported that antibiotic therapy has a negative effect on immunotherapy efficacy. Second, the gut microbiome of patients not responding to neoadjuvant pembrolizumab was characterized by a higher abundance of Ruminococcus bromii, while patients who showed a response were enriched in the genus Sutterella. Lastly, I started the implementation of in vivo and in vitro systems to test the mechanistic role of the bacteria identified in human samples. This thesis work reported innovative data on the role of different microbial communities (urinary/urothelium-bound/fecal) in bladder cancer and bladder cancer therapy, and provided novel in vivo and in vitro models to validate those finding and uncover the complex microbiome-host cells crosstalk in bladder cancer patients.
The microbiome has gained increasing momentum in cancer research, as it has become clear that microorganisms residing within our body are involved in mediating the cellular and tissue metabolism in health and disease. In bladder cancer research, there are different microbial communities that may mediate cancer pathobiology and response to therapy: the gut microbiome, the urinary microbiome, the urothelium-bound microbiome. These bacterial communities may mediate the processes of carcinogenesis or recurrence, modify the response to local intravesical therapies or influence the activity of systemic anticancer protocols. Based on these premises, my research project aimed to unveil the urinary and urothelium-bound microbiome in therapy-naïve bladder cancer patients, describing the differently enriched bacterial communities using a sex-based stratification. Compared to healthy controls, I found that the urine of men affected by bladder cancer were enriched in the order Opitutales and subordinate family Opitutaceae, together with the isolated class Acidobacteria-6, while in female patients I found enriched the genus Klebsiella. Notably, the bladder cancer tissue was enriched in the genus Burkholderia in both men and women, when compared to non-neoplastic, paired urothelium biopsies. Then, I also characterized the gut microbiome of bladder cancer patients undergoing neoadjuvant pembrolizumab to understand if the intestinal bacteria may influence the immune-mediated anticancer activity. In this set, I have reported that antibiotic therapy has a negative effect on immunotherapy efficacy. Second, the gut microbiome of patients not responding to neoadjuvant pembrolizumab was characterized by a higher abundance of Ruminococcus bromii, while patients who showed a response were enriched in the genus Sutterella. Lastly, I started the implementation of in vivo and in vitro systems to test the mechanistic role of the bacteria identified in human samples. This thesis work reported innovative data on the role of different microbial communities (urinary/urothelium-bound/fecal) in bladder cancer and bladder cancer therapy, and provided novel in vivo and in vitro models to validate those finding and uncover the complex microbiome-host cells crosstalk in bladder cancer patients.

Los estilos APA, Harvard, Vancouver, ISO, etc.

4

Benoni, Alexandra. "Oxytocin, as a hormonal treatment for cachexia in preclinical models". Electronic Thesis or Diss., Sorbonne université, 2022. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2022SORUS290.pdf.

Texto completo

Resumen

L'ocytocine (OT), une hormone neurohypophysaire, affecte le système nerveux central (SNC), l'utérus et les glandes mammaires. Il a été récemment démontré que l'OT favorise la différenciation myogénique et la régénération musculaire. En effet, les niveaux d'OT diminuent avec l'âge et son administration exogène contrecarre la sarcopénie chez les souris âgées. La cachexie est un syndrome caractérisé par une sévère fonte musculaire. Nous avons remarqué des niveaux inférieurs d'OT circulant chez les patients cachectiques atteints de cancer. Pour prouver que l'OT inhibe les facteurs dérivés de la tumeur, nous avons d'abord effectué des expériences in vitro montrant que l'inhibition de la différenciation myogénique exercée par le milieu conditionné par la tumeur C26 (CM) est inversée par le cotraitement avec l'OT. Ceci a été confirmée in vivo, car l'OT accélérait la régénération musculaire suite à une lésion focale, inhibé par le TNF. Dans un modèle préclinique, OT a restauré la masse musculaire squelettique, la taille des fibres et inhibé le catabolisme protéique. Nous nous sommes concentrés sur les effets de la tumeur et d’OT sur le métabolisme des protéines, en marquant spécifiquement les protéines nouvellement synthétisées. Dans les myoblastes co-cultivés avec des cellules tumorales, nous avons observé une diminution des protéines nouvellement synthétisées, contrecarré par le traitement OT. Nous montrons pour la première fois que l'OT est efficace pour contrecarrer les effets des facteurs dérivés de la tumeur
Oxytocin (OT), a neurohypophyseal hormone, affects the central nervous system (CNS), uterus, and mammary glands. OT has recently been shown to promote myogenic differentiation and muscle regeneration. Indeed, OT levels decrease with age and its exogenous administration counteracts sarcopenia in aged mice. Cachexia is a syndrome characterized by severe muscle wasting. We noticed lower levels of circulating OT in cachectic cancer patients. To prove that OT inhibits tumor-derived factors, we first performed in vitro experiments showing that the inhibition of myogenic differentiation exerted by C26 tumor-conditioned medium (CM) is reversed by co-treatment with OT. We confirmed in vivo that OT accelerated muscle regeneration following focal injury, inhibited by TNF. In a preclinical model, OT restored skeletal muscle mass, fiber size, and inhibited protein catabolism. We focused on the effects of tumor and OT on protein metabolism, specifically labeling newly synthesized proteins. In myoblasts co-cultured with tumor cells, we observed a decrease in newly synthesized proteins, counteracted by OT treatment. We show for the first time that OT is effective in counteracting the effects of tumor-derived factors

Los estilos APA, Harvard, Vancouver, ISO, etc.

5

MINOLI, LUCIA. "TUMOR MICROENVIRONMENT IN EXPERIMENTAL PRECLINICAL MOUSE MODELS OF HUMAN CANCER: MORPHOLOGICAL APPROACH". Doctoral thesis, Università degli Studi di Milano, 2020. http://hdl.handle.net/2434/704551.

Texto completo

Resumen

One of the recent advancements in oncological research has been the recognition of the tumor microenvironment (TME) as a relevant participant during all stages of the evolution of a neoplastic process. Indeed, over the past decades, tumors have been considered through a changing perspective: no longer as a growth of homogeneous neoplastic cells, but as an actual organ composed of different cell populations and structures: the parenchyma being the neoplastic population and the stroma, including the vascular network and infiltrating cells. The tumor microenvironment has a dual role in tumor biology, both promoting and antagonizing tumor development, growth, and local or distant invasiveness. According to its leading role in influencing tumor biology each component of the TME could be considered as a potential pharmacological target to be enhanced or antagonized, in order to influence tumor behavior. Accordingly, the study of the TME could provide new insights in the tumor biology and offers numerous potential targets for the development of novel therapeutic strategies. In this context, morphological techniques represent useful tools for the investigation of the TME, allowing the evaluation of the spatial distribution of the different elements, and provide useful complementary information to clinical and other data obtained in experimental in vivo studies. In this thesis, the three main classes of the TME components -tumor-associated vasculature, immune-inflammatory cells and tumor stroma- are illustrated in three different chapters and relevant experimental studies described. However, it should be considered that the various aspects of TME are not separate entities but are all involved in a dynamic system with complex structural and functional interactions. Chapter 1 – Tumor-associated vasculature Tumor angiogenesis has been identified as a hallmark of cancer, due to its central role in supporting tumoral growth, providing nutrient supply, removing catabolites and enabling tumoral metastatic dissemination. Most of the solid tumors are characterized by an “angiogenetic switch” in which an imbalance between pro- and anti-angiogenic factors sustains a dysregulated angiogenetic process, leading to the formation of an altered vascular network composed of structurally and functionally abnormal blood vessels. Drugs targeting tumor vasculature has been extensively studied as a mean to interfere with tumoral growth as well as to promote the delivery and/or effect of co-administered compounds to the tumor. In the first study of this chapter, we demonstrated the therapeutic efficacy and the antiangiogenic effect of a novel compound developed by binding sunitinib (a well-known antiangiogenic drug) to a selective binder of αVβ3 integrin thus promoting its delivery to the target site (tumors expressing αVβ3 integrin). The other studies of this chapter investigated the relation between tumor vasculature and tumor hypoxia. In particular, this relation was investigated to uncover the potential mechanism underlying the synergistic effect of the administration of an antiangiogenic compound (cediranib) with a poly-ADP ribose polymerase (PARP) inhibitor (olaparib) in a panel of patient-derived xenografts of ovarian carcinoma. Chapter 2 – Tumor immune microenvironment In most cancers, both innate and acquired immunity have a driving role during all stages of tumor development and progression. Depending on the cell population and/or molecular stimuli received, they can act in a dual way, antagonizing or promoting tumor growth. Three selected studies were described in chapter 2 and investigated: 1. The role of NK cells in hindering metastasis engraftment in a metastatic model of synovial sarcoma. After the combined administration of an heparanase-inhibitor with a tyrosine kinase inhibitor a significant reduction of lung metastases was observed and immunohistochemical analyses demonstrated the role of NK cells in this phenomenon. 2. The macrophage polarization status in a panel of xenotransplanted thyroid carcinoma tumors. The mononuclear-phagocyte populations infiltrating the tumors were evaluated by immunohistochemistry. 3. The role of inflammation in the development of colorectal cancer was evaluated in mice (wild type and EMILIN1-mutant), undergoing administration of AOM-SS (chemical carcinogenesis model). EMILIN1 mutant mice developed more numerous and more severe tumoral lesions compared to wild type, as well as increased inflammatory infiltrate was observed, unveiling a potential contribution of Emilin 1 in the pathogenesis of colorectal adenocarcinoma. Chapter 3 – Tumor stroma Tumor stroma represents not only the scaffold in which tumors growth, but also an intricate network of molecules and signals influencing tumor biology. The first study of this chapter investigated stroma-derived circulating molecules as a potential tool for the early diagnosis of pancreatic ductal adenocarcinoma (PDAC). Selected molecules (MMP-7, TIMP-1 and Throbospondin-2) were tested in KC genetically engineered mice (modeling the early stages of PDAC development) and patient-derived xenografts (modeling tumor progression), by serum ELISA and by immunohistochemistry. The second study evaluated the potential improvement in the biodistribution of chemotherapeutic drugs derived from the combined treatment with hyaluronidase. Tumor-bearing mice (ovarian carcinoma and pancreatic carcinoma models) were treated with chemotherapy alone (paclitaxel) or combined with hyaluronidase. Hyaluronidase treatment reduced the amount of stromal hyaluronic acid (as demonstrated by Alcian blue stain) and improved intratumor distribution of paclitaxel (as analyzed by mass spectrometry).

Los estilos APA, Harvard, Vancouver, ISO, etc.

6

Casagrande, Naike. "Anticancer activity of liposomal cisplatin in preclinical models of cervical and ovarian cancer". Doctoral thesis, Università degli studi di Padova, 2014. http://hdl.handle.net/11577/3423785.

Texto completo

Resumen

Cisplatin-based chemotherapy improves survival in cervical and ovarian cancer; however, treatment is associated with tumor resistance and significant toxicity. Lipoplatin (Regulon Inc., Mountain View, California) is a liposomal encapsulated form of cisplatin, developed in an effort to reduce cisplatin‟s systemic toxicity, while simultaneously improving the targeting of drugs to primary tumor and metastasis. Lipoplatin has been successfully administered in several randomized Phase II and III clinical trials, but not in cervical and ovarian cancer. The aim of this project was to analyze the antitumoral activity of lipoplatin in cisplatin-sensitive and cisplatin-resistant cervical and ovarian cancer cells. I evaluated the antiproliferative activity of lipoplatin, with cisplatin as reference drug, in the ME-180 cervical cancer cell line and its cisplatin-resistant clone R-ME-180, and in a panel of ovarian cancer cell lines: A2780, its cisplatin-resistant clone A2780cis, MDAH, OVACR3, OVCAR5, SKOV3, and TOV21G. Results demonstrated that lipoplatin exhibited a potent antitumoral activity in all the tested cell lines, including cisplatin-resistant cells, indicating that there is no cross-resistance between the two drugs. Lipoplatin induced apoptosis, as evaluated by Annexin-V staining and DNA fragmentation. In particular, it induced the mitochondrial apoptotic pathway causing mitochondrial membrane permeabilization, cytochrome-c release, Bcl-2 down-regulation, but Bax up-regulation, and caspases 9 and 3 activation. At the same experimental conditions cisplatin induced apoptosis only in cisplatin-sensitive cells. Moreover, lipoplatin, but not cisplatin, increased reactive oxygen species (ROS) accumulation and inhibited the enzymatic activity of thioredoxin reductase (TrxR), an enzyme involved in ROS detoxification and over-expressed in many tumor cells contributing to drug resistance. Furthermore, lipoplatin reduced EGFR expression and inhibited both migration and invasion. Multiple drug treatment is widely used in chemotherapy to obtain an additive or a synergistic effect (more than additive). I combined lipoplatin with the chemotherapeutic agents mostly used in ovarian cancer treatment. The results showed that the combination of lipoplatin with doxorubicin or abraxane demonstrated a synergistic effect, whereas the combination of lipoplatin with docetaxel or paclitaxel was less effective or at best additive. In the ascites of ovarian cancer patients there are multicellular aggregates or spheroids that are involved in tumor progression. Thus, spheroid-based assays are more predictive of in vivo therapeutic efficacy because they more closely resemble tumor microenvironment. Furthermore, cancer stem cells (CSC), rare tumor cells involved in initiating cancer growth, drug resistance, and disease recurrence, are also present in spheroids. The treatment with lipoplatin reduced stem cell markers in a dose-dependent manner and inhibited spheroid formation in both cervical and ovarian cancer models. Furthermore, it decreased ovarian cancer spheroid growth, vitality, and migration. Finally, lipoplatin treatment of nude mice with cervical and ovarian tumors significantly inhibited tumor growth in vivo, with low toxicities. Moreover, even after treatment interruption the tumors did not show any regrowth. In conclusion, in this project lipoplatin demonstrated an antitumoral activity in monolayer cultures, three-dimensional spheroids, and in vivo studies using cisplatin-resistant cervical and ovarian cancer cells. These promising results suggest lipoplatin as a novel chemotherapeutic agent for the treatment of cervical and ovarian cancer.
Il cisplatino è uno dei farmaci più utilizzati per il trattamento del carcinoma della cervice e dell‟ovaio. Purtroppo il suo utilizzo in chemioterapia presenta importanti limitazioni, quali l‟elevata tossicità e l‟insorgenza di resistenza intrinseca o acquisita. Il lipoplatino è una formulazione liposomiale del cisplatino (Regulon, Inc., Mt. View, U.S.A), sintetizzata allo scopo di ridurre la tossicità sistemica del cisplatino e contemporaneamente di incrementarne l‟accumulo nel tumore primario e nelle metastasi. Studi clinici di Fase II e III sono stati effettuati in diversi tumori ma non nel carcinoma della cervice uterina e dell‟ovaio. In questo lavoro è stata analizzata l‟attività antitumorale del lipoplatino in modelli preclinici di carcinoma della cervice uterina e carcinoma ovarico sensibili e resistenti al cisplatino. L‟attività antiproliferativa del lipoplatino è stata studiata nella linea cellulare derivata da carcinoma della cervice uterina ME-180 e nel suo clone resistente al cisplatino R-ME-180, come pure in un pannello di linee cellulari derivanti da carcinoma ovarico: A2780, il suo clone cisplatino-resistente A2780cis, MDAH, OVACR3, OVCAR5, SKOV3, e TOV21G. Il cisplatino è stato introdotto nello studio come farmaco di riferimento. I risultati hanno dimostrato che il lipoplatino esibisce una potente attività antitumorale in tutte le linee cellulari analizzate, incluse le cisplatino-resistenti, dimostrando assenza di cross-resistenza con il farmaco cisplatino. Il lipoplatino induce apoptosi, valutata tramite l‟esternalizzazione della fosfatidilserina (marcatore precoce di apoptosi) e la frammentazione del DNA. In particolare, il lipoplatino attiva la via mitocondriale dell'apoptosi, come dimostrato dalla depolarizzazione della membrana mitocondriale, il rilascio del citocromo-c , la diminuzione dell‟espressione della proteina anti-apoptotica Bcl-2, l‟incremento dell‟espressione della molecola pro-apoptotica Bax e l‟attivazione delle caspasi 9 e 3. Nelle stesse condizioni sperimentali il cisplatino attiva l‟apoptosi soltanto in cellule sensibili al cisplatino. L‟enzima tioredoxina reduttasi (TrxR) svolge una funzione ossidoriduttiva proteggendo la cellula da stress ossidativo. Un elevato livello dell‟enzima si osserva in diversi tipi di tumore e sembra essere associato alla resistenza al cisplatino. I miei studi hanno dimostrato che il lipoplatino, ma non il cisplatino, inibisce l‟attività enzimatica della TrxR incrementando la produzione di radicali liberi dell‟ossigeno (ROS). Inoltre il lipoplatino riduce l‟espressione del recettore del fattore di crescita dell‟epidermide (EGFR), un recettore di membrana over-espresso nei tumori, coinvolto nella proliferazione e nella migrazione delle cellule tumorali. Anche la migrazione e l‟invasione cellulare vengono ridotte dal trattamento con lipoplatino. Molto spesso in chemioterapia si somministra una combinazione di più farmaci (polichemioterapia) per ottenere un effetto additivo e/o sinergico. Si è quindi combinato il lipoplatino con i chemioterapici più utilizzati nel trattamento del carcinoma ovarico. La combinazione del lipoplatino con i farmaci doxorubicina e abraxane dimostra effetti sinergici, mentre la combinazione con docetaxel e paclitaxel è meno efficace con effetti quasi additivi. Nell‟ascite di pazienti affette da carcinoma ovarico si possono ritrovare aggregati multicellulari, o sferoidi, che sembrano essere coinvolti nella progressione tumorale. Gli sferoidi rappresentano un valido modello sperimentale con caratteristiche biologiche e molecolari simili ai tumori solidi, tra queste la presenza di cellule staminali cancerose, ossia cellule con grandi capacità rigenerative e di resistenza alle terapie in grado di alimentare la crescita del tumore. Il trattamento con lipoplatino diminuisce in maniera dose-dipendente i marcatori di staminalità e inibisce la formazione di sferoidi in entrambi i modelli sperimentali. Inoltre riduce la dimensione, la vitalità e la disseminazione di sferoidi di carcinoma ovarico. Infine il lipoplatino diminuisce la crescita di tumori xenografi derivanti da cellule di carcinoma della cervice uterina e dell‟ovaio con ridotta tossicità. Anche in seguito all‟interruzione del trattamento i tumori non riprendono la crescita. Concludendo il lipoplatino dimostra un‟attività antitumorale in colture cellulari tradizionali, in colture tridimensionali o sferoidi ed in vivo, sia di cellule derivanti da carcinoma della cervice uterina cisplatino-resistenti che da carcinoma ovarico. Questi risultati molto promettenti suggeriscono un potenziale utilizzo di questa formulazione liposomiale di cisplatino per il trattamento di pazienti affette dalle suddette patologie.

Los estilos APA, Harvard, Vancouver, ISO, etc.

7

García, Parra Jetzabel 1983. "PARP1 expression in breast cancer and effects of its inhibition in preclinical models". Doctoral thesis, Universitat Pompeu Fabra, 2012. http://hdl.handle.net/10803/84173.

Texto completo

Resumen

Breast cancer is the main cause of cancer death in women. Improved treatments, prevention programs and earlier detection are reducing the rate of death; however, there is still a high percentage of mortality by this cancer. Identification of novel targets to predict response to specific treatments is a key goal for personalizing breast cancer therapy and to improve survival. Few years ago, PARP inhibitors appeared as a promising therapy, particularly in BRCA-mutated cancers. However, there was a clear need to conduct further preclinical and translational work to improve the rational development of PARP inhibition in breast cancer. In this work we described PARP1 expression in breast tumour samples and characterized the effects of its inhibition in preclinical models. We found that nuclear PARP1 protein overexpression was associated with malignant transformation and poor prognosis in breast cancer. PARP1 overexpression was more common in triple negative subtype, but was also detectable in small subsets of estrogen receptor positive and HER2 positive breast cancers. In preclinical models, PARP1 played distinct roles in different molecular subtypes of breast cancer. Moreover, we described that olaparib (novel PARP inhibitor) had antitumour effects in different breast cancer subtypes, and its combination with trastuzumab (anti-HER2 antibody) enhanced the antitumour effects of this therapy.
El càncer de mama és la principal causa de mort per càncer en dones. La millora dels tractaments i la detecció precoç estan reduint la taxa de mort, però segueix sent elevada. Identificar noves dianes per predir la resposta a tractaments és clau per millorar les teràpies contra aquest càncer i la supervivència. Els inhibidors de PARP van aparèixer com una teràpia prometedora, particularment en càncers BRCA-mutants, però, cal dur a terme més estudis preclínics i translacionals per fomentar un desenvolupament racional d’aquesta teràpia en càncer de mama. Aquest treball descriu l’expressió de PARP1 en mostres de tumors mamaris i caracteritza els efectes de la seva inhibició a models preclínics. Vam observar que la sobreexpressió nuclear de la proteïna PARP1 fou associada amb: la transformació maligna; mal pronòstic en càncer de mama; i fou més freqüent al subtipus triple-negatiu, però també es va detectar en un subgrup de càncers de mama receptors d’estrogen positius i HER2 positius. En models preclínics, PARP1 va exercir rols diferents als diferents subtipus de càncer de mama. Per altra banda, vam descriure que olaparib (inhibidor de PARP) té efectes antitumorals en els diversos subtipus, i combinat amb trastuzumab (anticòs anti-HER2) potencia els efectes antitumorals d’aquesta teràpia.

Los estilos APA, Harvard, Vancouver, ISO, etc.

8

Jawad, Dhafer Sahib. "Chemopreventive effect of resveratrol in preclinical colorectal cancer models with different genetic drivers". Thesis, University of Leicester, 2017. http://hdl.handle.net/2381/40308.

Texto completo

Resumen

Previous reports indicate resveratrol can modulate many processes and targets in colorectal cancer (CRC) cells and rodent models but it is uncertain whether these effects translate to humans in vivo. The lack of relevant experimental models, particularly premalignant colorectal cells, the major targets for prevention, is a significant obstacle to translation of effective preventive agents to the clinic. Development of improved 3-dimensional organoid models with discrete mutational drivers (Apc, Apc+Kras and Braf) representing different subtypes of early CRC is an aim of this thesis. A further aim is to evaluate resveratrol across these models and examine in greater detail the ability of resveratrol to interfere with the development of cancers driven by mutant BrafV600E. Organoid cultures using intestinal cells isolated from genetically engineered mice and human cancer/adenoma tissue were successfully established and conditions optimised to allow long-term maintenance. Notably, the organoids derived from adenomas arising in Villin-Cre/BrafV600E mice constitute a novel preclinical model of CRC. After first demonstrating that resveratrol had anti-proliferative activity across a panel of human CRC cell lines with different mutation profiles it was tested in the organoids at clinically-achievable concentrations for effects on autophagy, senescence, apoptosis and stem cells. Administration of a high-fat diet to Villin-Cre/BrafV600E mice enhanced Braf-induced cryptal hyperplasia in a short-term study and this was significantly reduced by resveratrol. In a follow-up survival study, high dose resveratrol greatly prolonged the lifespan of Villin-Cre/BrafV600E mice on high-fat diet. However, resveratrol had no effect on the survival of mice given standard diet. Overall, these findings suggest a specific interaction between mutant Braf expressed in mouse intestine and high-fat, and that the effects are blocked by high dose resveratrol. Future studies are needed to investigate underlying mechanisms. Results suggest resveratrol may have value in the prevention of colorectal adenomas/cancers with different genetic alterations, including mutant BrafV600E.

Los estilos APA, Harvard, Vancouver, ISO, etc.

9

Gronbach, Leonie [Verfasser]. "Organotypic head and neck cancer models for advanced preclinical drug testing / Leonie Gronbach". Berlin : Freie Universität Berlin, 2021. http://d-nb.info/1230407316/34.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

10

Chen, Liu Qi. "Development and Application of AcidoCEST MRI for Evaluating Tumor Acidosis in Pre-Clinical Cancer Models". Diss., The University of Arizona, 2014. http://hdl.handle.net/10150/323450.

Texto completo

Resumen

Tumor acidosis is an important biomarker in cancer. We have developed a noninvasive imaging method, termed acidosis Chemical Exchange Saturation Transfer (acidoCEST) MRI to measure extracellular pH (pHe) in the tumor microenvironment. Chapter 1 introduces the importance of measuring tumor acidosis and presents various imaging modalities and their shortcoming to measure pHe. Chapter 2 describes the optimization of acidoCEST MRI for in vivo pHe measurement. The acidoCEST MRI protocol consists of a CEST-FISP acquisition and Lorentzian line shape fittings. We determined the optimal saturation time, saturation power and bandwidth, 5 sec, 2.8 µT and 90 Hz respectively. We also tried various routes of administration to increase contrast agent uptake in the tumor. We decided upon 200 µL bolus followed by 150 µL/hr infusion. The optimized acidoCEST MRI protocol was tested on a mammary carcinoma mouse model of MDA- MB-231. Our method can detect an increase in pHe in the bladder and tumor of the mice treated with bicarbonate. We used this optimized acidoCEST MRI method to measure pHe in lymphoma tumor model of Raji, Ramos and Granta 519 as described in Chapter 3. Pixel-wise pHe maps showed tumor heterogeneity. The pHe of Raji, Ramos and Granta 519 were determined to be mildly acidic with no significant difference. Chapter 4 describes the evolution of pixel-wise analysis in more detail. Besides the pHe map and spatial heterogeneity, we were able to determine the % contrast agent uptake. We monitored these biomarkers in two different mammary carcinoma mouse models, MDA- MB-231 and MCF-7 longitudinally and made comparisons between the different tumor models: MCF-7 were more acidic, more heterogeneous and faster growing than MDA- MB-231.

Los estilos APA, Harvard, Vancouver, ISO, etc.

11

Creedon, Helen. "Use of genetically engineered mouse models in preclinical drug development". Thesis, University of Edinburgh, 2015. http://hdl.handle.net/1842/15911.

Texto completo

Resumen

The paucity of well validated preclinical models is frequently cited as a contributing factor to the high attrition rates seen in clinical oncological trials. There remains a critical need to develop models which are accurately able to recapitulate the features of human disease. The aims of this study were to use genetically engineered mouse models (GEMMs) to explore the efficacy of novel treatment strategies in HER2 positive breast cancer and to further develop the model to facilitate the study of mechanisms underpinning drug resistance. Using the BLG--HER2KI-PTEN+/- model, we demonstrated that Src plays an important role in the early stages of tumour development. Chemopreventative treatment with dasatinib delayed tumour inititation (p= 0.046, Wilcoxon signed rank test) and prolonged overall survival (OS) (p=0.06, Wilcoxon signed rank test). Dasatinib treatment also induced squamous metaplasia in 66% of drug treated tumours. We used 2 cell lines derived from this model to further explore dasatinib’s mechanism of action and demonstrated reduced proliferation, migration and invasion following in vitro treatment. Due to the prolonged tumour latency and the low metastatic rate seen in this model, further studies were undertaken with the MMTV-NIC model. This model also allowed us to study the impact of PTEN loss on therapeutic response. We validated this model by treating a cohort of MMTV-NIC PTEN+/- mice with paclitaxel and demonstrated prolonged OS (p=0.035, Gehan Breslow Wilcoxon test). AZD8931 is an equipotent signalling inhibitor of HER2, HER3 and EGFR. We observed heterogeneity in tumour response but overall AZD8931 treatment prolonged OS in both MMTV-NIC PTEN FL/+ and MMTV-NIC PTEN+/- models. PTEN loss was associated with reduced sensitivity to AZD8931 and failure to suppress Src activity, suggesting these may be suitable predictive biomarkers of AZD8931 response. To facilitate further studies exploring resistance, we transplanted MMTV-NIC PTEN+/- fragments into syngeneic mice and generated 3 tumours with acquired resistance to AZD8931. These tumours displayed differing resistance strategies; 1 tumour continued to express HER2 whilst the remaining 2 underwent EMT and lost HER2 expression reflecting to a very limited degree some of the heterogeneity of resistance strategies seen in human disease. To further explore resistance to HER2 targeting tyrosine kinase inhibitors, we generated a panel of human cell lines with acquired resistance to AZD8931 and lapatinib. Western blotting demonstrated loss of HER2, HER3 and PTEN in all resistant lines. Acquisition of resistance was associated with a marked change in phenotype and western blotting confirmed all lines had undergone EMT. We used a combination of RPPA and mass spectrometry to further characterise the AZD8931 resistant lines and identified multiple potential novel proteins involved in the resistant phenotype, including several implicated in EMT. In conclusion, when coupled with appropriate in vitro techniques, the MMTV-NIC model is a valuable tool for selection of emerging drugs to carry forward into clinical trials of HER2 positive breast cancer.

Los estilos APA, Harvard, Vancouver, ISO, etc.

12

Marston, Gemma. "Anatomical and vascular imaging with high frequency ultrasound in preclinical models of colorectal cancer". Thesis, University of Leeds, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.598038.

Texto completo

Resumen

Colorectal cancer (CRC) is one of the most common malignancies in the western world and is the third most common cause of cancer related deaths in the UK. It has a good 5 year survival rate if the cancer is diagnosed at an early stage - 93% for Dukes' stage A; however, for late stage metastatic disease, this falls to only 7%. Improvements in treatment for metastatic disease, detection and screening are required to combat these low survival rates. Preclinical models, and in particular mouse models, are invaluable for studying the mechanisms which initiate tumour development and progression. Many models of CRC exist, including models of hereditary and sporadic CRC, including human CRC cell xenografts which support rapid tumour growth, allowing for relatively fast, short term studies and investigations into novel therapeutics. The ApcMin/+ mouse model recapitulates the early stages of human CRC development, with many polyps developing throughout the small intestine and colon. This project investigated the use of non-invasive imaging with high frequency ultrasound to provide anatomical information on the abdomen, and specifically the colon, of C57BI/6J mice, and the reproducibility of a protocol to measure the colon wall thickness in vivo. Once established, these techniques were then used to detect polyps in aged (170±34 days) and 90 day old ApcMin/+. mice, showing that this technique could be used with sensitivity and specificity of 48% and 100%, respectively. This project also investigated the feasibility of using contrast enhanced high frequency ultrasound to monitor the growth of human CRC cell xenografts and qualitatively and quantitatively assess their longitudinal vascular development in vivo. These data were then used as the basis of an intervention study, which incorporated the vascular disruptive agent Combretastatin A-4 into the CE-HFUS imaging protocols in order to assess the immediate vascular kinetic impact of CA4. This showed that CE-HFUS can detect and quantitate changes in tumour vascular kinetics in vivo following treatment with a known agent, suggesting that it may be useful in preclinical drug development. The work in this Thesis has demonstrated that C57BI/6 mouse colon wall thickness can be accurately determined in vivo, in an operator independent manner. Following on from the characterisation of colon wall thickness in wild type mice; this Thesis has shown for the first time that it is possible to identify colonic polyps in ApcMin/+ mice in vivo in both 90 day old and older age mice. Work in this Thesis has also characterised i for the first time with CE HFUS the blood flow kinetics and vascular perfusion of HCT116 CRC xenograft tumours in a longitudinal study. Building on this work, this Thesis has shown for the first time disruption in blood flow kinetics to HCT116 CRC xenograft tumours after exposure to CA4.

Los estilos APA, Harvard, Vancouver, ISO, etc.

13

Smolinski, Justin Bruce. "Dietary Chemoprevention Studies in Preclinical Models of Prostate Cancer: Bioactive Lipids and Vitamin D". The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1282069758.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

14

Lahr, Christoph Alexander. "Tissue-engineering humanised bone sarcoma models in rodents-a preclinical study platform for orthopaedic research". Thesis, Queensland University of Technology, 2021. https://eprints.qut.edu.au/207759/1/Christoph%20Alexander_Lahr_Thesis.pdf.

Texto completo

Resumen

This thesis is a step forward in preclinical in-vivo disease modelling, designed to find new diagnostic and therapeutic options, to ultimately improve the poor outcome of patients with primary bone cancer. Combining the principles of tissue-engineering, 3D-printing and advanced gene editing techniques the preclinical animal models developed in this thesis have important clinical implications that could shape future innovative treatment plans. Particularly the translation of a humanised osteosarcoma model from a mouse into a newly engineered severely immunocompromised rat will facilitate preclinical primary bone cancer research by opening up new experimental avenues for complex surgical resection and reconstruction models.

Los estilos APA, Harvard, Vancouver, ISO, etc.

15

Martínez, Pérez Carlos. "Evaluation of the antitumour activity of novel flavonoids on pre-clinical models of breast and ovarian cancer". Thesis, University of Edinburgh, 2017. http://hdl.handle.net/1842/25410.

Texto completo

Resumen

New drugs are needed for better cancer management. Clinical trials are currently underway to assess the use of flavonoids (natural polyphenols) as anticancer agents. Among them, myricetin has been shown to induce cell cycle arrest and apoptosis in pre-clinical cancer models. We hypothesised that myricetin-derived novel flavonoids designed to enhance this natural potential and improve on the drug-likeness limitations of myricetin might have increased potential for their application in the management of breast and ovarian cancer. The effect of a library of novel flavonoids was screened on 3 panels of breast and ovarian cancer cell lines, representing different molecular subtypes and phenotypes, to assess their potency. The second-generation bi-methoxylated analogue AO-1530-OMe (Oncamex) was identified as the most effective candidate in the library, with sub-micromolar concentrations exerting a strong antiproliferative effect across almost all models studied. Results suggested that changes in the hydroxylation profile, the addition of methoxylations and a decyl alkyl chain were some of the structure-activity relationships contributing to this improved efficacy. Plate assays showed 8 h treatment with Oncamex reduced cell viability and induced cytotoxicity and apoptosis, concomitant with caspase activation and PARP cleavage. Pre-incubation with an antioxidant partially blocked these effects, suggesting the possible involvement of ROS modulation in the mechanism of action of Oncamex. Fluorescence microscopy reported the quick and stable delivery of Oncamex to the mitochondria. Fluorescent probes showed that Oncamex can induce mitochondrial superoxide production at concentrations associated with its antiproliferative effects. Study of the electrochemical properties of Oncamex by cyclic voltammetry supported this. Differential gene expression analysis following a microarray experiment showed Oncamex induces changes in the expression of genes controlling cell cycle and apoptosis. Together with previous results, the findings from this analysis led to the postulation of a model for the mechanism of action of Oncamex: due to its enhanced reactivity and mitochondrial targeting, Oncamex can generate mitochondrial superoxide, leading to mitochondrial dysfunction, membrane permeabilisation and the activation of the JNK pathway and the transcription factor FOXO3, which together contribute to the induction of intrinsic apoptosis and the inhibition of proliferation. Further proliferation assays on cell culture models also reported enhanced effect of Oncamex when administered in combination with paclitaxel and TRAIL. These improved responses were observed in breast and ovarian cancer models, including cells lines characterised by their treatment-resistant phenotype. Cotreatment with Oncamex also improved the effect of tamoxifen on anti-oestrogen resistant LCC9 breast cancer cells. Results from preliminary in vivo studies in mice implanted with the MDA-MB-231 breast cancer xenograft were consistent with an antiproliferative effect of Oncamex (25mg/kg/day) in vivo, as treatment inhibited tumour growth and reduced the expression of the marker of proliferation Ki-67 without signs of systemic toxicity. Tissues from this experiment also allowed for preliminary in vivo validation of the proposed mechanism of action of Oncamex by immunohistochemistry. The in vivo cytostatic effect of Oncamex was confirmed in a second in vivo experiment, which also investigated the effect of Oncamex at higher doses or in combination with paclitaxel. In conclusion, the novel flavonoid Oncamex has shown a promising antiproliferative effect in pre-clinical models of breast and ovarian cancer, including models of treatment-resistant cancers. Preliminary in vivo studies have demonstrated a partial recapitulation of the effect of Oncamex. A mechanistic model has been proposed by which Oncamex induces intrinsic apoptosis through its redox reactivity and mitochondrial targeting. These results support the potential of this prototypic candidate, although possible work in the structure and formulation of this candidate and further study and validation of its mechanism of action is needed for its continued development as an anticancer agent.

Los estilos APA, Harvard, Vancouver, ISO, etc.

16

D'Alesio, C. "IDENTIFICATION OF NOVEL EPIGENETIC TARGETS THAT SUSTAIN BREAST CANCER GROWTH". Doctoral thesis, Università degli Studi di Milano, 2016. http://hdl.handle.net/2434/365894.

Texto completo

Resumen

Breast cancer is the second leading cause of tumor-related death in women, mainly due to resistance to first line therapy, high risk of relapse and metastatic dissemination. Breast cancer is a highly heterogeneous disease, which displays diverse biological characteristics, clinical behaviour and prognosis. For these reasons, it has become challenging the identification and characterization of novel genes responsible for breast cancer initiation and progression. To identify new targets that sustain breast cancer growth, we performed in vivo and in vitro shRNA screens in a human breast cancer cell model. We screened two libraries targeting several chromatin remodeling enzymes (around 200 in total), which are essential genes in breast cancer maintenance and represent optimal druggable candidates. We identified approximately 70 genes that were depleted in our screens, and among them, we selected five hits to validate the screens. Remarkably, the silencing of each target gene significantly reduced tumor growth in vivo and decreased proliferation, colony formation and migration in vitro, thus validating our screens. We deeply investigated the Chromodomain Helicase DNA binding Domain 4 (CHD4) gene, whose silencing in breast cancer cells greatly reduces tumor growth, but does not affect normal mammary epithelial proliferation and migration. We examined the role of CHD4 in primary cells derived from spontaneous mammary tumors of MMTV/NeuT transgenic mice. Upon CHD4 depletion, we confirmed a significant decrease of tumor growth in vivo and cell proliferation and migration in vitro. Intriguingly, we demonstrated that CHD4 silencing reduced tumor growth in vivo in a patient-derived xenopatient (PDX) model of Luminal B drug-resistant breast carcinoma. Moreover, we investigated the mechanism through which CHD4 promotes breast cancer cell proliferation and we showed that CHD4 regulates cell cycle progression of breast cancer cells. CHD4 depletion provokes a consistent accumulation of cells in the G0/G1 phase and a strong reduction of the S phase of the cell cycle, and an upregulation of p21. In summary, RNAi screens allowed us to identify CHD4 as a critical target that sustains human breast cancer. Importantly, we showed that CHD4 modulation does not modify normal mammary cell proliferation and migration, suggesting that its targeting in tumor cells might not impact on the surrounding normal tissues. Moreover, CHD4 is crucial in almost any subtype of breast cancer, as shown by its effect on MMTV/NeuT and PDX tumorigenesis. Finally, we demonstrated that CHD4 is a key regulator of breast cancer cell cycle.

Los estilos APA, Harvard, Vancouver, ISO, etc.

17

Piggott, Luke. "Investigating the therapeutic potential of cellular FLICE-like inhibitory protein and TRAIL in preclinical models of breast cancer". Thesis, Cardiff University, 2012. http://orca.cf.ac.uk/44561/.

Texto completo

Resumen

Apoptosis is an important process in normal mammary gland physiology and evasion of apoptosis has also been identified as a hallmark of cancer. In breast cancer cells apoptotic resistance is an acquired feature that can promote tumour growth and progression. Induction of apoptosis by the extrinsic death ligand TRAIL has been shown to be a promising clinical therapy targeting a number of different cancer cells whilst sparing normal cells. Unfortunately most breast cancers are inherently resistant to TRAIL treatment. Herein it is shown that by reducing the expression of the downstream TRAIL inhibitor c-FLIP, a range of different breast cancer subtypes can be sensitised to TRAIL treatment resulting in significant cancer cell death. Significantly, suppression of c-FLIP in combination with TRAIL (FLIPi/TRAIL) ablated the tumour-initiating breast cancer stem cell (bCSC) subset, as defined by mammosphere formation assay, within cell lines. This selective killing of bCSCs translated to reduced tumour initiation and metastasis in animal transplant models. However, continued culture of FLIPi/TRAIL treated cell lines in adherent conditions resulted in bCSC re-acquisition suggesting a phenotypic plasticity of non-bCSC cells. Re-acquired bCSCs also demonstrated sensitivity to repeated FLIPi/TRAIL treatment and maintaining reduced c-FLIP expression prevented bCSC re-acquisition. These results substantiate the importance of resistance to apoptosis in tumour initiation and metastasis and identify the targeting of c-FLIP proteins as a promising anti-cancer therapeutic approach. Acquired resistance to existing mainstay therapies such as antiestrogens (AEs) (tamoxifen and Faslodex) and aromatase inhibitors (AIs) is an ongoing obstacle in treatment of a large number of breast cancer patients. AE-resistant models of breast cancer and a multiple endocrine-resistant patient sample demonstrated hypersensitivity to TRAIL. This sensitivity was observed in both in vitro and in vivo models of AE resistance and cell death was prevalent in both bulk tumour cells and bCSCs. Sensitisation was not attributed to combination AE/TRAIL treatment suggesting cellular changes during the acquisition of AE resistance are responsible for TRAIL sensitivity in these models. Further investigation suggested that the mechanism of AE-resistant cell sensitivity to TRAIL was not dependant on functional estrogen receptor signalling and is most likely dependant on the AE agent that the cancer cells have acquired resistance to. Interestingly tamoxifen-resistant MCF-7 cells were shown to have reduced c-FLIP protein expression compared to parental cells, further supporting c-FLIP’s potential in cancer therapy. Recent success in the use non-MHC-restricted γδ T cells as a targeted immunotherapy in clinical trials has identified this therapeutic methodology as desirable. Here it is shown that TRAIL is readily expressed by this subset of T cells that also demonstrate cytotoxicity to breast cancer cell lines. Neither the secretion of TRAIL or surface expression of TRAIL appeared to contribute significantly towards γδ T cell cytotoxicity and the majority of breast cancer cell death induced by γδ T cells would seem to be perforin-mediated. The suppression of c-FLIP in target cells increased γδ T cell cytotoxicity but again not via TRAIL. Preliminary results also indicated that the bCSCs of some cell lines were exquisitely sensitive to γδ T cell treatment. In summary these results indicate that targeting c-FLIP and TRAIL can be therapeutically beneficial in a range of different breast cancer subtypes by certain therapeutic strategies.

Los estilos APA, Harvard, Vancouver, ISO, etc.

18

Giusti, Veronica <1990&gt. "Preclinical Development of novel therapeutic approaches in models resistant to targeted therapies in HER2-positive mammary breast cancer". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amsdottorato.unibo.it/8849/1/Giusti_Veronica_tesi.pdf.

Texto completo

Resumen

HER2 enriched mammary breast cancer represents 15-25% of mammary carcinomas and is associated to increased aggressiveness and worse prognosis. Advent of targeted therapies against HER2 has improved 5-year survival up to 75%, nevertheless receptor discordance, which is observed in 10.8% of metastasis, as well as resistance to targeted therapies render it a still challenging disease. On the one hand, taking advange of a recently estabilished murine model of spontaneous loss of HER2 expression, we sought to understand the underlying mechanism, to evaluate role of trastuzumab and to identify identify druggable targets in HER2-negative metastasis or relapses of HER2-positive tumors. The study of transcriptome of cell lines with different HER2 expression has permitted us to identify pathways related to the modulation of this more malignant phenotype, which appeared to be promoted by trastuzumab. Some indications emerged for inhibition of PDGFR-B by sunitinib in tumours which have lost HER2 expression. On the other hand, a recently established collection of patient derived xenografts (PDX) was used to obtain models of progression where to evaluate the effect of neratinib, a pan-HER tyrosine kinase inhibitor. No abrupt loss of HER2 expression was registered in these models. Collectively, our data, obtained in ER-/PR- HER2+ PDX, strongly indicate a great and long-lasting efficacy of neratinib even in trastuzumab-resistance and after progression and call for further evaluation of neratinib in advanced clinical settings. In our PDX diagnosed as luminal B expressing HER2 (score 2+), neratinib alone had no effect but synergized with tamoxifen and their combination tended to confer a little survival benefit in vivo, thus underscoring the possible relevance of dual blockade in tumors expressing both hormone receptors and HER2.

Los estilos APA, Harvard, Vancouver, ISO, etc.

19

Ferreira, Luís Pedro Correia Pinto. "Development of multicelular 3D cancer testing platforms for evaluation of new anti-cancer therapies". Master's thesis, Universidade de Aveiro, 2017. http://hdl.handle.net/10773/22713.

Texto completo

Resumen

Mestrado em Bioquímica Clínica
O cancro do pulmão (CP) é um dos cancros mais diagnosticados a nível mundial e também um dos mais mortíferos. Atualmente, as terapias administradas a nível clínico para o tratamento do CP são ainda extremamente ineficazes e limitadas no que diz respeito ao aumento da taxa de sobrevivência dos pacientes oncológicos. Esta realidade demonstra a necessidade de investigar ativamente novas terapias para o tratamento desta neoplasia. No entanto a validação pré-clínica de terapias inovadoras para o CP tem-se revelado extremamente difícil devido à inexistência de plataformas que sejam adequadas para testes a nível laboratorial, uma vez que as culturas celulares in vitro bidimensionais (2D), recomendadas pelas agências regulatórias são incapazes de mimetizar as caraterísticas principais dos tumores humanos. Estas limitações têm originado uma fraca correlação entre a performance das terapias nos estudos in vitro e a obtida em ensaios clínicos controlados. Neste contexto, os modelos de tumores tridimensionais (3D) in vitro têm vindo a ser reconhecidos como uma solução para este problema, pois podem recapitular várias componentes do microambiente tumoral. Das várias plataformas 3D in vitro de CP investigadas atualmente muito poucas avaliaram o papel da inclusão de células estaminais mesenquimais (MSCs). Para colmatar esta lacuna, o trabalho de investigação desenvolvido no âmbito desta dissertação descreve a produção e otimização de novos modelos hétero-celulares 3D in vitro. Estas plataformas são compostas por células tumorais do CP (A549) e do seu estroma, nomeadamente fibroblastos da pele e células estaminais mesenquimais derivadas da medula óssea (BM-MSCs). Estes três tipos de células foram co-cultivadas em micropartículas poliméricas de policaprolactona revestidas por ácido hialurónico, com o objetivo de incluir este componente da matriz extracelular que se encontra presente no microambiente do CP. Esta abordagem permitiu formar a nível laboratorial microtecidos multicelulares 3D híbridos que melhor mimetizam a heterogeneidade celular das neoplasias pulmonares. Os resultados obtidos demonstraram que os microtumores formados através da técnica de sobreposição-líquida são reprodutíveis em termos de morfologia e tamanho, apresentaram núcleos necróticos, organização celular 3D e produziram proteínas do microambiente tumoral. Além destas caraterísticas, os dados obtidos através de microscopia de fluorescência revelaram que as BM-MSCs migram para o interior dos microtumores ao longo do tempo. A avaliação da citotoxicidade da Doxorubicina, um fármaco anti-tumoral rotineiramente utilizado a nível clínico, demonstrou que a inclusão de micropartículas aumenta a resistência das células tumorais em modelos homotípicos. Nos modelos tri-cultura heterotípicos a citotoxicidade foi comparável à obtida em microtumores sem micropartículas. Estes resultados evidenciam assim o papel importante dos fibroblastos e das BM-MSCs na resposta dos microtumores. Numa visão global, os modelos 3D formados recapitulam com mais exatidão o microambiente do cancro do pulmão e poderão servir no futuro como plataformas de teste para descobrir ou aperfeiçoar novas terapias, ou combinações de terapêuticas, para este tipo de neoplasia.
Lung cancer (LC) is one the most commonly diagnosed cancers worldwide, being also one of the deadliest. Currently, clinically administered therapies for treatment of LC are still extremely ineffective and limited in increasing oncologic patients survival rates. This reality evidences the necessity of actively investigating novel therapies for the treatment of LC. However, preclinical validation of novel therapies as revealed itself as an extremely arduous process, due to the lack of suitable laboratory testing platforms since the recommend in vitro bi-dimensional (2D) cell cultures are unable to fully mimic the main hallmarks of human tumors. In this context, in vitro tridimensional (3D) tumor models are being increasingly recognized as a solution due to their ability to correctly recapitulate several characteristics of the tumor microenvironment (TME). Amongst currently developed 3D in vitro platforms for the study of LC, few have included or studied the role of mesenchymal stem cells (MSCs). To provide further insights into this hypothesis, the research work developed in this thesis describes the production and optimization of novel heterotypic in vitro 3D models, comprised by non-small-cell lung cancer cells (A549) and stromal cells, namely skin fibroblasts (HFs), and bone-marrow derived mesenchymal stem cells (BM-MSCs). These three diverse cell populations were co-cultured in hyaluronic acid coated polymeric polycaprolactone microparticles (LbL-MPs) as to include this key extracellular matrix component of LC TME. This approach allowed the formation of 3D multicellular heterotypic microtissues (3D-MCTS) that better recapitulate the cellular heterogeneity of LC TME in the laboratory. The obtained findings demonstrate that these models formed via the liquid-overlay technique were reproducible in terms of morphology and size, presented necrotic core formation, 3D cellular organization, and deposited matrix proteins in a similar manner as in the TME. Besides this, fluorescence microscopy data revealed that BM-MSCs migrated overtime into the microtumors core . Performed doxorubicin in vitro cytotoxicity assays revealed that the inclusion of LbL-MPs lead to an increased resistance of homotypic A549 monoculture models against this anti-cancer drug commonly used in clinical treatments. Alongside, the cytotoxicity obtained in triculture heterotypic models was comparable to that of microtumors without LbL-MPs inclusion, showcasing the role of HFs and BM-MSCs in microtumors response to therapy. Globally, the herein bioengineered 3D models were able to recapitulate with an increased precision the TME of LC, making them suitable test platforms for development or improvement of standalone or combinatorial therapies for this type of neoplasia.

Los estilos APA, Harvard, Vancouver, ISO, etc.

20

Ruocco, Margherita <1981&gt. "Generation and characterization of mouse models of Small cell lung cancer and Basal cell carcinoma for the preclinical evaluation of new therapies". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amsdottorato.unibo.it/5623/1/Ruocco_Margherita_TESI.pdf.

Texto completo

Resumen

Background. Human small cell lung cancer (SCLC) accounting for approximately 15-20% of all lung cancers, is an aggressive tumor with high propensity for early regional and distant metastases. Although the initial tumor rate response to chemotherapy is very high, SCLC relapses after approximately 4 months in ED and 12 months in LD. Basal cell carcinoma (BCC) is the most prevalent cancer in the western world, and its incidence is increasing worldwide. This type of cancer rarely metastasizes and the death rate is extraordinary low. Surgery is curative for most of the patients, but for those that develop locally advanced or metastatic BCC there is currently no effective treatment. Both types of cancer have been deeply investigated and genetic alterations, MYCN amplification (MA) among the most interesting, have been found. These could become targets of new pharmacological therapies. Procedures. We created and characterized novel BLI xenograft orthotopic mouse models of SCLC to evaluate the tumor onset and progression and the efficacy of new pharmacological strategies. We compared an in vitro model with a transgenic mouse model of BCC, to investigate and delineate the canonical HH signalling pathway and its connections with other molecular pathways. Results and conclusions. The orthotopic models showed latency and progression patterns similar to human disease. Chemotherapy treatments improved survival rates and validated the in vivo model. The presence of MA and overexpression were confirmed in each model and we tested the efficacy of a new MYCN inhibitor in vitro. Preliminar data of BCC models highlighted Hedgehog pathway role and underlined the importance of both in vitro and in vivo strategies to achieve a better understanding of the pathology and to evaluate the applicability of new therapeutic compounds

Los estilos APA, Harvard, Vancouver, ISO, etc.

21

Ruocco, Margherita <1981&gt. "Generation and characterization of mouse models of Small cell lung cancer and Basal cell carcinoma for the preclinical evaluation of new therapies". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amsdottorato.unibo.it/5623/.

Texto completo

Resumen

Background. Human small cell lung cancer (SCLC) accounting for approximately 15-20% of all lung cancers, is an aggressive tumor with high propensity for early regional and distant metastases. Although the initial tumor rate response to chemotherapy is very high, SCLC relapses after approximately 4 months in ED and 12 months in LD. Basal cell carcinoma (BCC) is the most prevalent cancer in the western world, and its incidence is increasing worldwide. This type of cancer rarely metastasizes and the death rate is extraordinary low. Surgery is curative for most of the patients, but for those that develop locally advanced or metastatic BCC there is currently no effective treatment. Both types of cancer have been deeply investigated and genetic alterations, MYCN amplification (MA) among the most interesting, have been found. These could become targets of new pharmacological therapies. Procedures. We created and characterized novel BLI xenograft orthotopic mouse models of SCLC to evaluate the tumor onset and progression and the efficacy of new pharmacological strategies. We compared an in vitro model with a transgenic mouse model of BCC, to investigate and delineate the canonical HH signalling pathway and its connections with other molecular pathways. Results and conclusions. The orthotopic models showed latency and progression patterns similar to human disease. Chemotherapy treatments improved survival rates and validated the in vivo model. The presence of MA and overexpression were confirmed in each model and we tested the efficacy of a new MYCN inhibitor in vitro. Preliminar data of BCC models highlighted Hedgehog pathway role and underlined the importance of both in vitro and in vivo strategies to achieve a better understanding of the pathology and to evaluate the applicability of new therapeutic compounds

Los estilos APA, Harvard, Vancouver, ISO, etc.

22

Alshammari, Fatemah O. F. O. "An immunohistopathological and functional investigation of β3 integrin antagonism as a therapeutic strategy in cancer : characterisation, development, and utilisation of preclinical cancer models to investigate novel β3 integrin anatgonists". Thesis, University of Bradford, 2013. http://hdl.handle.net/10454/6327.

Texto completo

Resumen

Tumour cell dissemination is a major issue with the treatment of cancer, thus new therapeutic strategies which can control this process are needed. Antagonism of integrins highly expressed in tumours is one potential strategy. The integrins are transmembrane glycoprotein adhesive receptors. Two of the integrins, αVβ3 and αIIbβ3, are highly expressed in a number of tumours and induce bi-directional signalling through their interaction with extracellular matrix proteins, and growth factor receptors. Through this signalling they play an important role in a number of cellular processes that are involved in tumour dissemination such as tumour growth, migration, invasion, metastasis and angiogenesis. Dual αIIbβ3 and αVβ3 integrin antagonism will have a direct effect on β3-expressing tumour cells that leads to the inhibition of cell migration and dissemination. Furthermore, through targeting tumour cell interaction with endothelial cells and platelets, this will also lead to inhibition of angiogenesis and metastasis. The aim of this project was to characterise the expression of αVβ3 and αIIbβ3 integrin in a panel of tumour cell lines and in human tumour xenograft samples, and to develop and utilise cell-based models to investigate potential novel β3 antagonists. The expression of αV and β3 subunits was detected in xenograft tissue using immunoblotting techniques. A panel of cell lines of different tumour types including melanoma, prostate, breast, colon and non small cell lung carcinoma was then characterised for αVβ3 and αIIbβ3 integrin expression using immunoblotting and immunocytochemistry. Melanoma cell lines demonstrated the strongest αVβ3 expression. No αIIbβ3 integrin expression was seen in any of the cell lines evaluated. A selection of cell lines with varying αVβ3 expression were then used to develop a functional test for cell migration, the scratch wound healing assay. Migration of tumour cells that expressed αVβ3 integrin was inhibited by the known β3 antagonists, cRGDfV peptide and LM609 antibody. A panel of 12 potential novel β3 integrin antagonists was screened for cytotoxicity and activity in the validated scratch assay. ICT9055 was the most effective antagonist in inhibition of M14 cell migration as determined by the scratch assay, with an IC₅₀ of < 0.1 μM. Therefore the work presented in this thesis has established models and tools for evaluating potential novel β3 integrin antagonists, and identified a promising molecule to progress for further preclinical evaluation.

Los estilos APA, Harvard, Vancouver, ISO, etc.

23

Sargeant, Aaron Matthew. "Preclinical Efficacy and Safety Evaluation of Novel Small-Molecule Targeted Agents for the Prevention and Treatment of Prostate Cancer". The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1243948876.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

24

O'Farrell, Alice C. "Development of in vivo tumour models for non-invasive proof-of-principle investigation of novel therapeutic agents. Engineering and characterisation of bioluminescent cell reporter systems for in vivo analysis of anti-cancer therapy pharmacodynamics". Thesis, University of Bradford, 2011. http://hdl.handle.net/10454/5391.

Texto completo

Resumen

Despite significant advances in cancer treatment, clinical response remains suboptimal and there is a continued requirement for improved chemotherapeutics. The attrition rate for new therapies is high, due principally to lack of in vivo efficacy and poor pharmacodynamics. Consequently better systems are required to determine in vivo preclinical efficiency and drug-target interactions. Engineering of cancer cells to express fluorescent or bioluminescent proteins, either endogenously or under the control of specific gene promoters, and their detection by noninvasive optical imaging has the potential to improve preclinical drug development. In this study, a panel of colorectal cancer cell lines were engineered to express fluorescent and luminescent proteins either constitutively or under control of gene-promoters for the DNA damage response gene p53 or the cell cycle regulator p21, both important pharmacodynamic sensors. These cell lines were characterised for their potential as in vivo models of primary and metastatic tumour therapy response, several showing significant potential. In addition to the development of these models, this study also addressed the pharmacokinetics of different luciferase substrates and identified optimal temporal and dose characteristics for each. Furthermore, a new application for bioluminescent imaging was developed and validated for use in preclinical evaluation of vascular disrupting agents, a new generation of cancer therapeutic. This study demonstrates that despite the dynamic and variable nature of fluorescent and bioluminescent imaging, reproducible results can be obtained if appropriate precautions are taken. The models developed herein will expedite cancer drug development whilst reducing and refining the use of animals in research.

Los estilos APA, Harvard, Vancouver, ISO, etc.

25

O'Farrell, Alice Claire. "Development of in vivo tumour models for non-invasive proof-of-principle investigation of novel therapeutic agents : engineering and characterisation of bioluminescent cell reporter systems for in vivo analysis of anti-cancer therapy pharmacodynamics". Thesis, University of Bradford, 2011. http://hdl.handle.net/10454/5391.

Texto completo

Resumen

Despite significant advances in cancer treatment, clinical response remains suboptimal and there is a continued requirement for improved chemotherapeutics. The attrition rate for new therapies is high, due principally to lack of in vivo efficacy and poor pharmacodynamics. Consequently better systems are required to determine in vivo preclinical efficiency and drug-target interactions. Engineering of cancer cells to express fluorescent or bioluminescent proteins, either endogenously or under the control of specific gene promoters, and their detection by noninvasive optical imaging has the potential to improve preclinical drug development. In this study, a panel of colorectal cancer cell lines were engineered to express fluorescent and luminescent proteins either constitutively or under control of gene-promoters for the DNA damage response gene p53 or the cell cycle regulator p21, both important pharmacodynamic sensors. These cell lines were characterised for their potential as in vivo models of primary and metastatic tumour therapy response, several showing significant potential. In addition to the development of these models, this study also addressed the pharmacokinetics of different luciferase substrates and identified optimal temporal and dose characteristics for each. Furthermore, a new application for bioluminescent imaging was developed and validated for use in preclinical evaluation of vascular disrupting agents, a new generation of cancer therapeutic. This study demonstrates that despite the dynamic and variable nature of fluorescent and bioluminescent imaging, reproducible results can be obtained if appropriate precautions are taken. The models developed herein will expedite cancer drug development whilst reducing and refining the use of animals in research.

Los estilos APA, Harvard, Vancouver, ISO, etc.

26

Fend, Laetitia. "Utilisation de modèles pré-cliniques murins orthotopiques et transgéniques pour l'évaluation d'approches immunothérapeutiques dans le traitement du cancer". Thesis, Strasbourg, 2014. http://www.theses.fr/2014STRAJ058.

Texto completo

Resumen

Dans l’approche expérimentale de l’immunothérapie des tumeurs solides, les modèles murins sont utilisés pour des raisons de rapidité et de reproductibilité. Le plus souvent, les modèles tumoraux murins sont ectopiques ce qui constitue un modèle artificiel qui ne reflète qu’une partie de la réalité biologique de tumeurs provenant de diverses origines.Mon projet de thèse a consisté à mettre au point de nouveaux modèles pré-cliniques murins permettant de mieux mimer les situations pathologiques des tumeurs solides chez l’homme. Pour cela, je me suis notamment intéressée à un modèle orthotopique de cancer du rein (implantation de cellules RenCa ou RenCa-MUC1 dans la capsule rénale) et à un modèle spontané de cancer du sein (souris MMTV-PyMT). Ces modèles ont ensuite permis l’évaluation de trois différentes approches d’immunothérapie à savoir la thérapie virale oncolytique, la vectorisation d’antigènes tumoraux au moyen d’un vecteur viral ainsi que la thérapie via un anticorps monoclonal
In experimental approaches to immunotherapy of cancer, mouse tumor models are used for reasons of speed and reproducibility. Ectopic mouse tumor models are the most often used, but they constitute artificial models that reflect only a part of the biological reality of tumors from various origins.The aim of my thesis project was to develop new mouse preclinical tumor models to better mimic the pathological situations of solid tumors in humans. First, I developed an orthotopic model of kidney cancer (subcapsular kidney implantation of a renal carcinoma cell line which either expressed or did not express the human xeno-antigen, MUC1). In addition to this, I also studied a spontaneous model of breast cancer (MMTV-PyMT).These models enabled us to evaluate the efficacy of three different immunotherapy approaches namely oncolytic virus strategy, tumor antigen vectorization by using a viral vector, and monoclonal antibody

Los estilos APA, Harvard, Vancouver, ISO, etc.

27

Rolff, Jana. "Charakterisierung von in vivo Modellen des humanen nicht-kleinzelligen Lungenkarzinoms zur Therapieoptimierung". Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2012. http://dx.doi.org/10.18452/16515.

Texto completo

Resumen

Das Bronchialkarzinom ist die häufigste Todesursache bei den Krebserkrankungen und weist eine schlechte Prognose auf. Die Behandlung besteht aus einer Chemotherapie mit platinbasierten Medikamenten, doch der Erfolg ist unbefriedigend. In den letzten Jahren wurden zielgerichtete Therapien gegen Proteine wie den EGFR entwickelt. Klinische Studien zeigten, dass nur Subpopulationen von den Medikamenten Erlotinib und Cetuximab profitieren. Eine bessere (Vor-)Selektion der Patienten ist wünschenswert, um unnötige Behandlungen zu vermeiden. Für diese Analysen bedarf es relevanter präklinischer Modelle. Im Rahmen dieser Arbeit wurden 25 Xenograftmodelle des Lungenkarzinoms vergleichend charakterisiert. Ein Schwerpunkt bestand im Vergleich der Xenografts mit ihren Patiententumoren. Die Analyse der Histologie, der Proliferationsmarker als auch der Genexpressionsprofile fand übereinstimmende Ergebnisse in den Patiententumoren und ihren abgeleiteten Xenografts. Mit Hilfe von mRNA-, Protein- und SNP-Profilen ressistenzassoziierter Marker der Chemotherapie konnte die Bedeutung der Modelle zur Charakterisierung von prädiktiven und prognostischen Markern aufklärt werden. Diese Arbeit untersuchte auch Marker der anti-EGFR-Therapien. mRNA- und Proteinprofile der ERBB-Rezeptoren sowie der Liganden wurden erstellt und stimmten mit publizierten klinischen Daten überein. Genexpressionsstudien in Erlotinib Respondern und Non-Respondern zur Therapieoptimierung identifizierten den Wachstumsfaktor VEGFA als Ziel für eine Kombinationsbehandlung mit dem Angiogeneseinhibitor Bevacizumab. Die Kombination von Bevacizumab mit Erlotinib führte zu einem reduzierten Tumorwachstum. Die Ergebnisse dieser Arbeit machten deutlich, dass die individuellen Tumoreigenschaften in den patientenabgleiteten Xenografts auf Gen- und Proteinebene erhalten bleiben und diese als Modelle zur Markeranalyse sowie zur Therapieoptimierung eingesetzt werden können.
Lung cancer is still one of the most frequent cancers worldwide. The treatment option is classical chemotherapy that is based upon the combination of platin-based drugs. But no further improvement seems to be possible. For some years targeted drugs against single proteins like the EGFR were developed. The clinical trials showed that only subpopulations of patients benefit from the treatment. A better selection of patients to avoid treatment would be helpful. Therefore, pre-clinical models that are suitable for analysis and that represent clinical populations of patients are required. In this work 25 patient derived xenografts from lung cancer were intensely studied. First, the xenografts were compared with their corresponding patient tumor. The analysis of the histology and the expression of proliferation and epithelial or mesenchymal markers showed concordance of the patient tumor and the derived xenograft. The gene expression profiles were also maintained. Further analysis should elucidate the relevance of the xenografts as models for the characterisation and validation of predictive and prognostic markers. SNP, mRNA and protein expression profiles of resistance markers for chemotherapy were generated and showed similarities with clinical data. As marker for the anti-EGFR targeted therapies the ERBB receptors and the ligands of the EGFR were analysed. The mRNA and protein expression profiles resemble clinical data sets. An optimisation of the therapy should be achieved with gene expression studies. The vascular endothelial growth factor A was identified for a combination treatment with the anti-angiogenic drug bevacizumab in erlotinib resistant tumors. The combination of erlotinib and bevacizumab reduced the tumor growth in selected models. In summary, the analysis could show that the individual characteristics of the patient tumor were maintained in the xenograft. The models are a reliable tool for studies designed to improve treatment strategies.

Los estilos APA, Harvard, Vancouver, ISO, etc.

28

Baka, Zakaria. "Élaboration de cancers sur puce pour des applications en thérapies anticancéreuses". Electronic Thesis or Diss., Université de Lorraine, 2023. http://www.theses.fr/2023LORR0175.

Texto completo

Resumen

Le cancer de l’ovaire constitue un véritable enjeu de santé public. Les nouveaux traitements se heurtent par ailleurs à des taux d’échec très élevés. Ceci s’explique notamment pour le manque de fiabilité des modèles précliniques classiques tels que la culture cellulaire en 2D. De nouveaux outils basés sur la culture cellulaire en 3D ont alors fait leur apparition tels que les sphéroïdes et les organoïdes. Or ces modèles ont leurs propres limites (coûts, difficultés d’application). La bio-impression 3D est une nouvelle approche permettant de créer des modèles tumoraux de manière contrôlée et reproductible. Néanmoins, elle a encore très peu été appliquée au cancer ovarien. En plus de la troisième dimension, il est important de prendre en compte les conditions dynamiques associées à l’environnement tumoral. Ceci est possible depuis quelques années grâce à la technologie des cancers sur puce basée sur la microfluidique. Cependant, cette technologie ne permet pas, à l’heure actuelle, de simuler le trajet vasculaire du médicament en amont de son interaction avec le tissu tumoral. Dans ce projet de thèse, nous avons souhaité créer un modèle tridimensionnel et dynamique du cancer ovarien en combinant les approches de bio-impression 3D et de microfluidique. Dans un premier temps, la bio-impression 3D a été utilisée pour créer la structure tumorale à proprement parlé. Pour y parvenir, nous avons formulé un hydrogel de gélatine et d’alginate de sodium dans lequel nous avons intégré des cellules cancéreuses ovariennes (SKOV-3) et des fibroblastes cancéreux (MeWo). Le tissu tumoral bio-imprimé a ensuite été caractérisé par différentes techniques pour démontrer sa viabilité et sa pertinence biologique. Sa réponse au cisplatine a également été évaluée. Dans un second temps, nous avons intégré le modèle tumoral bio-imprimé au sein d’un support microfluidique. Le rôle de ce support était de permettre la mise en culture du tissu bio-imprimé sous flux physiologique. Il devait également permettre de simuler le trajet vasculaire du médicament avant son interaction avec le tissu tumoral. Par la suite, nous avons fait appel à la simulation en mécanique des fluides pour concevoir une version améliorée du premier système. L’objectif étant de pouvoir tester, en même temps, plusieurs concentrations différentes de médicament sur un même dispositif microfluidique. Ce projet de thèse a démontré la capacité de la bio-impression 3D à créer des tissus tumoraux ovariens viables et fonctionnels. Il a par ailleurs ouvert des perspectives de recherche très intéressantes par rapport aux possibilités de combiner la bio-impression 3D et de la microfluidique en vue d’améliorer la modélisation préclinique des cancers ovariens
Ovarian cancer is a major public health issue. Moreover, new treatments still face very high failure rates. This is mainly due to the unreliability of conventional preclinical models such as 2D cell culture. Thus, new tools based on 3D cell culture have emerged such as spheroids and organoids. However, these models have their own limitations (cost, difficulty of application). 3D bioprinting is a new approach to create tunable and reproducible tumor models. However, very few bioprinted tumor models have been reported so far. Besides the “third dimension”, it is important to consider the dynamic conditions of the tumor environment. This has been possible for some years now thanks to microfluidics-based cancer-on-a-chip technology. However, this technology currently does not simulate the drug vascular transport before its interaction with the tumor cells. In this PhD project, we set out to create a dynamic, three-dimensional model of ovarian cancer by combining 3D bioprinting and microfluidics. First, 3D bioprinting was used to create the tumor structure itself. For that, we formulated a bio-ink comprising SKOV-3 ovarian cancer cells and MeWo cancer fibroblasts embedded in a gelatin – alginate hydrogel. The bioprinted tumor structures were then characterized by various techniques to demonstrate their viability and biological relevance. Their response to anticancer drug cisplatin was also assessed. In the second step, we integrated the bioprinted tumor model into a microfluidic support for culture under physiological flow. This support was also intended to simulate the drug's vascular transport prior to interaction with the tumor tissue. We then used computational fluid dynamics to design an improved version of the first system. The aim of this improved version was to simultaneously assess multiple drug concentrations. This PhD project demonstrated the ability of 3D bioprinting to create viable and functional ovarian tumor models. It has also brought interesting research prospects with regard to the possibilities of combining 3D bioprinting and microfluidics to improve preclinical modeling of ovarian tumors

Los estilos APA, Harvard, Vancouver, ISO, etc.

29

Calatayud, Anna-Line. "Développement et caractérisation de modèles précliniques de carcinomes hépatocellulaires pour l'évaluation de la réponse thérapeutique et l'étude des mécanismes de l'hépatocarcinogenèse". Thesis, Université de Paris (2019-....), 2020. https://theses.md.univ-paris-diderot.fr/CALATAYUD_Anna_Line_va2.pdf.

Texto completo

Resumen

Le carcinome hépatocellulaire (CHC), souvent diagnostiqué tardivement, est un cancer extrêmement agressif et résistant aux traitements proposés pour les stades avancés. De plus, la majorité des récents essais cliniques de phase 2 ou 3 se sont soldés par des échecs liés au développement de multiples mécanismes de résistance. Dans ce contexte l’étude de modèles précliniques est très utile pour comprendre la biologie moléculaire du CHC et chercher de nouvelles cibles thérapeutiques ou biomarqueurs spécifiques de la réponse aux traitements. Ainsi, dans ce travail, l’étude de lignées cellulaires dérivées de CHC qui représentent un sous-groupe de tumeurs agressives mais récapitulent une diversité moléculaire du CHC, nous a permis d’associer certains contextes moléculaires spécifiques à la réponse aux traitements et d’établir plusieurs nouvelles hypothèses thérapeutiques. Ces lignées nous ont également permis de comprendre que la surexpression de MET comme critère d'inclusion des patients expliquait les échecs des essais cliniques du tivantinib et de proposer l’expression de Ki67 comme un meilleur biomarqueur prédictif de son efficacité antitumorale. Enfin, l’étude de modèles murins de coopération oncogénique a permis de mettre en évidence pour la première fois le rôle suppresseur de tumeurs de RSK2 dans la carcinogenèse hépatique, en coopération avec l’inactivation d’AXIN1 ou l’activation de la voie Wnt/β-caténine. Dans l’ensemble, cette étude montre que les modèles précliniques sont extrêmement informatifs, malgré leurs différentes limites, ils permettent d’apporter de nouvelles hypothèses thérapeutiques. En particulier dans ce travail, la mise en évidence du rôle crucial de l’activation de la voie RAS-MAPK dans le développement du CHC renforce l’intérêt de l’utilisation d’inhibiteurs de MEK1/2 dans de futurs essais cliniques dans des sous-groupes candidats
Hepatocellular carcinoma (HCC) is a very aggressive malignancy, which is resistant to current therapeutic options for advanced stages. In addition, most of recent phase 2 or 3 clinical trials failed due to the development of multiple resistance mechanisms. In this context, preclinical models are very useful to understand the molecular biology of HCC and looking for new therapeutic targets or specific biomarkers of treatment response. Thus, in this work, the study of HCC cell lines that represent a subgroup of aggressive tumors but recapitulate the molecular diversity of HCC enabled us to show associations between specific molecular contexts and response to treatments allowing to establish several new therapeutic hypotheses. Thanks to these cell lines we also understand that the overexpression of MET as a criterion for inclusion of patients in tivantinib clinical trials explained its failures and to propose the expression of Ki67 as a better biomarker predictive of its antitumor efficacy. Finally, by studying murine models of oncogenic cooperation, we highlighted for the first time the tumor suppressor role of RSK2 in hepatic carcinogenesis, in cooperation with the inactivation of AXIN1 or the activation of the Wnt/β-catenin pathway. Overall, this study shows that preclinical models are extremely informative, despite their various limitations, they allow to bring new therapeutic hypotheses. In particular we demonstrated the crucial role of the RAS-MAPK pathway activation in HCC development reinforcing the interest of the use of MEK1/2 inhibitors in future clinical trials in candidate subgroups

Los estilos APA, Harvard, Vancouver, ISO, etc.

30

Herrault, Guillaume. "Nouvelles stratégies thérapeutiques dans le traitement du gliome infiltrant du tronc cérébral". Electronic Thesis or Diss., Bordeaux, 2024. http://www.theses.fr/2024BORD0301.

Texto completo

Resumen

Les DIPG (Diffuse Intrinsic Pontine Glioma) sont des tumeurs cérébrales pédiatriques rares dont la survie médiane après diagnostic est inférieure à un an. Le traitement de référence de ce cancer repose sur la radiothérapie mais cette dernière n’est pas curative. La recherche de nouvelles stratégies thérapeutiques innovantes est donc indispensable pour permettre une prise en charge clinique efficace des enfants atteints d’un DIPG.En 2022, notre équipe a montré in vitro et in vivo que l’inhibition de l’activité méthyltransférase d’EZH2 par le GSK126 sensibilisait les cellules de DIPG aux statines par une augmentation de la synthèse de cholestérol. Cependant, le mécanisme d’action induisant cet effet synergique entre les deux composés restait inconnu. Nos résultats ont montré que l’utilisation du GSK126 entraine une augmentation du métabolisme du cholestérol mais également de celui des acides gras, le tout associé à une accumulation de gouttelettes lipidiques plus importante. Nous avons également montré que le GSK126 tuait de façon sélective les cellules tumorales les plus souches (OPC-like) et que les cellules résistantes mettaient en place un programme pro-survie. Par analyse transcriptomique, nous avons découvert que le GSK126 induit de nombreuses voies moléculaires impliquées dans le stress oxydatif, le stress du réticulum endoplasmique et la mise en place des processus autophagique/mitophagique et l’inflammasome NLRP3. Nos résultats ont également montré que le traitement par le GSK126 empêchait l’activation de la phosphorylation de STAT3-Y705 et induisait la mort cellulaire par pyroptose des cellules les plus sensibles. Enfin, ces travaux ont permis de mettre en évidence l’importance du processus de prénylation protéique dans le programme pro-survie des cellules malgré le stress cellulaire. Le ciblage combiné de certains de ces processus et de l’inhibition de l’activité méthyltransférase d’EZH2 a montré un effet antitumoral synergique dans des modèles in vitro.En parallèle, nous avons réalisé un criblage pharmacologique sur un modèle 3D de cellules différenciées de DIPG afin d’identifier de nouvelles cibles thérapeutiques. Nos résultats ont montré une forte sensibilité de ces cellules à des inhibiteurs de la dynamique des microtubules. Une analyse kinomique sur des cellules traitées par un inhibiteur de microtubules a montré l’activation d’une kinase impliquée dans le contrôle de la division cellulaire et des dommages à l’ADN. Cette seconde étude a, elle aussi, conduit à la découverte d’un effet antitumoral synergique in vitro entre des inhibiteurs de ces deux cibles
DIPG (Diffuse Intrinsic Pontine Glioma) is a rare paediatric brain tumour with a median survival after diagnosis of less than one year. The standard treatment for this cancer is radiotherapy, but this is not curative. Research into new and innovative therapeutic strategies is therefore essential to enable effective clinical management of children with DIPG.In 2022, our team showed in vitro and in vivo that inhibition of EZH2 methyltransferase activity by GSK126 sensitised DIPG cells to statins by increasing cholesterol synthesis. However, the mechanism of action inducing this synergistic effect between the two compounds remained unknown. Our results showed that the use of GSK126 increased both cholesterol and fatty acid metabolism, associated with a greater accumulation of lipid droplets. We also showed that GSK126 selectively killed the most proliferating tumour cells (OPC-like) and that resistant cells set up a pro-survival programme. By transcriptomic analysis, we discovered that GSK126 induced numerous molecular pathways involved in oxidative stress, endoplasmic reticulum stress and the setting up of autophagic/mitophagic processes and NLRP3 inflammasome. Our results also showed that treatment with GSK126 prevented the activation of STAT3-Y705 phosphorylation and induced cell death by pyroptosis in the most sensitive cells. Finally, this work highlighted the importance of the protein prenylation process in the pro-survival programme of cells despite cellular stress. Combined targeting of some of these processes and inhibition of EZH2 methyltransferase activity has shown a synergistic anti-tumour effect in in vitro models.In parallel, we carried out a pharmacological screening on a 3D model of differentiated DIPG cells to identify new therapeutic targets. Our results showed that these cells are highly sensitive to inhibitors of microtubule dynamics. A kinomic analysis of cells treated with a microtubule inhibitor showed the activation of a kinase involved in the control of cell division and DNA damage. This second study also led to the discovery of a synergistic anti-tumour effect in vitro between inhibitors of these two targets

Los estilos APA, Harvard, Vancouver, ISO, etc.

31

INTERNATI, M. CHIRIVA. "PRECLINICAL TESTING OF GALECTIN-3C FOR MULTIPLE MYELOMA". Doctoral thesis, Università degli Studi di Milano, 2012. http://hdl.handle.net/2434/168390.

Texto completo

Resumen

The American Cancer Society expects that there will be more than 20,000 new cases of multiple myeloma (MM) in the US in 2011 and despite the new treatments now available, the median survival rate is only 5 years. Galectin-3C (Gal-3C) is a human lectin involved in cellular processes including cellular differentiation, apoptosis, neoplastic transformation, and metastasis. Gal-3C contains the carbohydrate recognition domain (CRD) of galectin-3 and is thought to act as a dominant negative inhibitor of galectin-3-mediated cross-linking. Gal-3C is a proprietary truncated, inhibitory form of galectin-3. Results showed that in a subcutaneous U266 cell NOD/SCID mouse model of human MM, treatment with an N-terminally truncated form of galectin-3, termed Gal-3C significantly inhibited tumor growth. Furthermore, in vitro data indicated that Gal-3C acts by inhibition of angiogenesis, MM cell migration and invasion, and NF-kB activation. Moreover, Gal-3C facilitates the antitumor activity of bortezomib, a proteasome inhibitor for MM treatment. Gal-3C and bortezomib also synergistically inhibited MM-induced angiogenesis activity in vitro. The delivery of Gal-3C to patients will be via a pump during initial clinical trials. In the long-term, the plan is to develop a formulation of Gal-3C for sustained release to increase survival for patients with MM.

Los estilos APA, Harvard, Vancouver, ISO, etc.

32

Sensi, Francesca. "Recellularized colorectal patient-derived scaffold as in vitro pre-clinical 3D model for drug screening". Doctoral thesis, Università degli studi di Padova, 2019. http://hdl.handle.net/11577/3423320.

Texto completo

Resumen

Purpose: Colorectal cancer (CRC), the third most common cancer diagnosed in both men and women shows a highly ineffective therapeutic management. In contrast, CRC is a rare pediatric tumor, representing only 1% of all pediatric malignancies, with an incidence of approximately 1 per million. In this context, an urgent needing not yet addressed is the random assignment to adjuvant chemotherapy of high-risk stage II and stage III colon cancer patients, both young and adults, without any predictive factor of efficacy. Secondly, in the field of drug discovery the critical step is the preclinical evaluation of drug cytotoxicity, efficacy, and efficiency. We purpose to develop a patient-derived 3D preclinical model useful for drug evaluation that can mimic in vitro the patient's disease. Methods: Surgically resected healthy colon mucosa and matched CRC were decellularized by a detergent-enzymatic treatment (DET). DET scaffolds were recellularized with HT29 cells. Qualitative and quantitative characterization of matched recellularized samples were evaluated through histology, immunofluorescences and DNA amount quantification. Chemosensitivity test was performed using increasing concentration of 5-Fluorouracil (5-FU), range 0.1 µM to 100 µM. In vivo studies were carried out using the zebrafish (Danio rerio) animal model. For cancer xenograft assays, HT29 cells were injected into the duct of Couvier and subsequently incubated in 96-well plates with different concentrations of 5-FU. Drug absorption and perfusion along fresh and DET tumor scaffolds were evaluated qualitative using autofluorescence of doxorubicin (doxo, 594nm) and quantitative calculated by Darcy’s law. Buffy coat-derived monocytes were cultured with DET scaffolds and macrophages lineage markers were evaluated with flow cytometry. Results: Decellularization protocol allowed the preservation of original structure and ultrastructure (SEM analysis). Five days after recellularization with HT29 cell line, the 3D CRC model exhibited reduced sensitivity to 5-FU treatments compared with conventional 2D culture. Calculated IC50 resulted in 11.5 µM and 1.3 µM of 5-FU, respectively. In the zebrafish transplantation model, HT29 extravasation was detected after 4 days post injection. Moreover, we obtained a 5-FU IC50 comparable with that observed in the 3D CRC model. Using confocal microscopy, we demonstrated that doxorubicin diffuses through the volume of 3D CRC model and co-localize with the cell nuclei which repopulate the 3D CRC scaffold. Finally, we observed that monocytes exposed to tumor decellularized ECM differentiated towards a pro-tumoral anti-inflammatory macrophage-like profile. Conclusion: 3D CRC model could be preclinical reliable tool to bridge the gap between in vitro, in vivo and ex vivo drug testing assays. The 3D CRC model, translated in the pediatric setting, could help clinicians and oncologists to identify the most suitable treatment for the patient.

Los estilos APA, Harvard, Vancouver, ISO, etc.

33

Sanchez, Herrero Alvaro. "Tissue engineering of an orthotopic humanised bone-organ as a platform for preclinical multiple myeloma research". Thesis, Queensland University of Technology, 2020. https://eprints.qut.edu.au/203046/1/Alvaro_Sanchez%20Herrero_Thesis.pdf.

Texto completo

Resumen

This Thesis presents the first steps of the development of a humanized and patient-specific mouse model of multiple myeloma (MM). Novel therapeutic approaches are getting increasingly complex and relevant pre-clinical drug testing is becoming a great challenge. The mouse model presented here features a humanized bone marrow compartment with a humanized bone shell that is able to engraft MM cells and patient-derived hematopoietic stem cells, mimicking myeloma bone disease serving as a unique platform for MM drug testing and discovery.

Los estilos APA, Harvard, Vancouver, ISO, etc.

34

Aziz, Robeena M. "Utilization of a preclinical model for chemoprevention of esophageal cancer employing a food-based and single- agent approach". Columbus, Ohio : Ohio State University, 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1086122566.

Texto completo

Resumen

Thesis (Ph. D.)--Ohio State University, 2004.
Title from first page of PDF file. Document formatted into pages; contains xvi, 154 p.; also includes graphics (some col.). Includes abstract and vita. Advisor: Gary D. Stoner, School of Public Health. Includes bibliographical references (p. 143-154).

Los estilos APA, Harvard, Vancouver, ISO, etc.

35

Hartl, Christina [Verfasser]. "Combination therapy targeting both innate and adaptive immunity improves survival in a preclinical model of ovarian cancer / Christina Hartl". Tübingen : Universitätsbibliothek Tübingen, 2021. http://d-nb.info/1234450720/34.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

36

Brüggemann, Sabrina [Verfasser], Dagmar [Akademischer Betreuer] Knebel-Mörsdorf y Hildegard [Akademischer Betreuer] Büning. "Generation of an oncolytic adenovirus vector combining three cancer targeting strategies and characterization of a new preclinical model for breast cancer virotherapy / Sabrina Brüggemann. Gutachter: Dagmar Knebel-Mörsdorf ; Hildegard Büning". Köln : Universitäts- und Stadtbibliothek Köln, 2012. http://d-nb.info/1038234689/34.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

37

Colombo, Pierre-Emmanuel. "Nouveaux vecteurs polymères et modèles expérimentaux en vue de la délivrance intrapéritonéale prolongée d’agents anti tumoraux dans le traitement des cancers de l’ovaire". Thesis, Montpellier 1, 2012. http://www.theses.fr/2012MON1T003.

Texto completo

Resumen

Le cancer de l'ovaire est la première cause de décès par cancer gynécologique. Cette thèse avait pour objectif la prospection de nouvelles solutions thérapeutiques fondées sur la délivrance prolongée d'agents anti tumoraux à l'aide de systèmes macromoléculaires de synthèse. L'un des obstacles majeurs était la disposition d'un modèle de tumeur pertinent chez l'animal. Après un examen bibliographique des connaissances acquises, le deuxième chapitre examine le potentiel d'un panel de xénogreffes dérivées de tumeurs ovariennes humaines directement greffées chez la souris immunodéprimée. Il est montré que les principales caractéristiques phénotypiques et moléculaires des tumeurs originales sont maintenues au niveau des greffes. Les résultats traduisent la présence d'une hétérogénéité intra-tumorale et d'une oligoclonalité au niveau des tumeurs primaires. L'ensemble confirme l'importance du choix du modèle tumoral pour l'évaluation de nouveaux traitements et l'étude des mécanismes aboutissant aux rechutes de la maladie et au développement d'une chimiorésistance. Un troisième chapitre traite l'exemple d'un système de délivrance prolongée fondé sur le couplage d'un agent antitumoral modèle, la doxorubicine, associé de diverses manières à un vecteur macromoléculaire biorésorbable, le poly(L-lysine citramide). Le premier conjugué obtenu par couplage direct sur le vecteur étant trop stable, divers systèmes ont été conçus pour obtenir la libération souhaitée. L'utilisation d'un bras espaceur clivable de type ester-hydrazone a fourni le meilleur résultat. Pour pallier la complexité de ces conjugués, une stratégie innovante fondée sur le piégeage de la doxorubicine dans une gélatine artificielle à base de poly(N-acryloyl glycinamide) est prospectée qui devrait permettre l'utilisation simultanée de plusieurs principes actifs piégés temporairement par voie physique dans un gel adhésif et fournir des solutions mieux adaptées aux contraintes cliniques des traitements intrapéritonéaux
Ovarian carcinoma is the most lethal gynecologic malignancy. The aim of this PhD thesis was to develop new therapeutic approaches based on novel synthetic macromolecular drug delivery systems for intraperitoneal chemotherapy. These objectives were limited by the requirement of reliable tumor models for experimental studies. After a concise review of knowledge published in the literature, the potential interest of the establishment of a collection of tumor grafts derived from samples of human tumors is examined in a second chapter. Data show that the major phenotypic and genotypic features of the original tumors are maintained in the xenografts. They also confirm the importance of this tumor model to test new drugs and to analyze intratumoral heterogeneity and oligoclonality in primary ovarian carcinoma. The collection will be also helpful to study the mechanisms leading to disease recurrences and resistance to chemotherapies. An example of drug delivery system based on the different associations of a model chemotherapeutic drug (doxorubicin) with a bioresorbable macromolecular vector, namely poly(L-lysine citramide), is addressed in a third chapter. Direct amid linkage in the first conjugate was too stable with respect to antitumoral cytotoxicity desired after in vivo administration and different systems were generated subsequently to increase drug release in tumor deposits. The best results were obtained with a hydrazone cleavable spacer containing an ester group. To overcome the complexity of these conjugates, a novel strategy based on doxorubicin entrapment in a synthetic gelatin made of (poly(N-acryloyl glycinamide) is developed. This strategy should allow physical temporary entrapment of different drug molecules in a adhesive gel and could provide new solutions to the therapeutic challenges of intraperitoneal administration

Los estilos APA, Harvard, Vancouver, ISO, etc.

38

Lebdai, Souhil. "Potentialisation de la photothérapie dynamique à visée vasculaire par une modulation des cellules myéloïdes par le récepteur CSF-1R dans un modèle préclinique de cancer de la prostate Les traitements focaux : une alternative dans la prise en charge du cancer de la prostate de bas risque ? Potentiating vascular-targeted photodynamic therapy through CSF-1R modulation of myeloid cells in a preclinical model of prostate cancer". Thesis, Sorbonne université, 2019. http://www.theses.fr/2019SORUS521.

Texto completo

Resumen

La photothérapie dynamique à visée vasculaire utilisant le WST11 (VTP) induit la destruction rapide des tissus ciblés et constitue un traitement prometteur pour le cancer de la prostate. Cependant, la réponse immunitaire qui en résulte, qui peut jouer un rôle important dans la potentialisation ou l’atténuation des effets de la VTP, n’a toujours pas été comprise. Les cellules myéloïdes, telles que les MDSC et les macrophages, sont souvent présentes dans les tumeurs et sont largement associées à l'angiogenèse, au remodelage tissulaire et à l'immunosuppression. On sait également que ces cellules jouent un rôle essentiel dans la cicatrisation des plaies, induite lors de la destruction rapide des tissus. Nous avons étudié les effets de la VTP sur le recrutement de cellules myéloïdes infiltrant la tumeur (TIM), en particulier les MDSC et les macrophages associés aux tumeurs (TAM), dans les modèles de cancer de la prostate murin Myc-Cap et TRAMP C2. Nous rapportons que la VTP augmentait à la fois l'infiltration de cellules myéloïdes dans les tumeurs, mais aussi l’expression de CSF1R ; CSF1R étant un récepteur nécessaire à la différenciation, à la prolifération et à la migration des cellules myéloïdes. Comme un traitement anti-CSF1R avait déjà été utilisé pour diminuer l’infiltration de cellules myéloïdes dans d'autres modèles murins de cancer de la prostate, nous avons émis l'hypothèse que l'association d'un anti-CSF1R à un traitement par VTP entraînerait une diminution de la repousse tumorale et une amélioration de la survie. Nous avons constaté que le ciblage des cellules myéloïdes en utilisant un anti-CSF1R en association avec la VTP diminuait le nombre de MDSC et de TAM, et en particulier les macrophages M2. De plus cette association induisait une infiltration accrue de cellules T CD8+, diminuait la croissance tumorale et prolongeait la survie globale. Ces résultats suggèrent que le ciblage des cellules myéloïdes via le récepteur CSF1R est une stratégie prometteuse pour potentialiser les effets anti-tumoraux de la VTP
Vascular-targeted photodynamic therapy (VTP) induces rapid destruction of targeted tissues and is a promising therapy for prostate cancer. However, the resulting immune response, which may play an important role in either potentiating or blunting the effects of VTP, is still incompletely understood. Myeloid cells such as myeloid-derived suppressor cells (MDSCs) and macrophages are often found in tumors and are widely reported to be associated with cancer angiogenesis, tissue remodelling and immunosuppression. These cells are also known to play a critical role in wound-healing, which is induced by rapid tissue destruction. In this study, we investigated the effects of VTP on the recruitment of tumor infiltrating myeloid cells, specifically MDSCs and tumor-associated macrophages (TAMs), in the Myc-Cap and TRAMP C2 murine prostate cancer models. We report that VTP increased the infiltration of myeloid cells into the tumors, as well as their expression of CSF1R, a receptor required for myeloid differentiation, proliferation and tumor migration. As anti-CSF1R treatment has previously been used to deplete these cells types in other murine models of prostate cancer, we hypothesized that combining anti-CSF1R with VTP therapy would lead to decreased tumor regrowth and improved survival. Importantly, we found that targeting myeloid cells using anti-CSF1R in combination with VTP therapy decreased the number of tumor MDSCs and TAMs, especially M2 macrophages, as well as increased CD8+ T cell infiltration, decreased tumor growth and improved overall survival. These results suggest that targeting myeloid cells via CSF1R targeting is a promising strategy to potentiate the anti-tumor effects of VTP

Los estilos APA, Harvard, Vancouver, ISO, etc.

39

Pérez, lanzón María. "Modeling Hormone Receptor Positive Breast Cancer in Immunocompetent Mice Blocking tumor-educated MSC paracrine activity halts osteosarcoma progression Organoids for Modeling Genetic Diseases. In: International Review of Cell and Molecular Biology A preclinical mouse model of osteosarcoma to define the extracellular vesicle-mediated communication between tumor and mesenchymal stem cells Failure of immunosurveillance accelerates aging The metabolomic signature of extreme longevity: Naked mole rats versus mice Lurbinectedin synergizes with immune checkpoint blockade to generate anticancer immunity Laminin-binding integrins are essential for the maintenance of functional mammary secretory epithelium in lactation Immunoprophylactic and immunotherapeutic control of hormone receptor-positive breast cancer". Thesis, université Paris-Saclay, 2021. http://www.theses.fr/2021UPASL019.

Texto completo

Resumen

Les progrès de la recherche sur le cancer du sein dépendent de la disponibilité d’outils appropriés, comme les lignées cellulaires qui peuvent être implantées chez des souris immunocompétentes. La souche de souris C57Bl/6 est la plus étudiée et c’est la seule pour laquelle certaines variantes génétiques sont disponibles. Étant donné qu'aucune lignée cellulaire de carcinome mammaire à récepteurs hormonaux positifs de souche C57Bl/6 n'est disponible, nous avons décidé d'établir des lignées cellulaires de ce type. Nous avons induit des cancers du sein chez des souris C57BL/6 femelles en utilisant un analogue synthétique de la progestérone combiné à un agent endommageant l'ADN. Des lignées cellulaires ont été établies à partir de ces tumeurs et sélectionnées pour leur positivité au niveau du double récepteur (estrogène + progestérone), ainsi que pour leur transplantabilité chez les femelles C57BL/6. Parmi plusieurs lignées, une lignée cellulaire, que nous avons appelée MD5, remplissait ces critères et a permis l'établissement de tumeurs mal différenciées et très prolifératives. Ces tumeurs ont réduit leur croissance (sans toutefois régresser) lors du traitement par des antagonistes des récepteurs d’œstrogènes, ainsi que par une chimiothérapie à base d'anthracylines. Cependant, ce dernier effet n'a pas été influencé par la déplétion des lymphocytes T et, en outre, ces tumeurs n'ont pas répondu au blocage de PD-1, ce qui suggère que les tumeurs MD5 sont immunologiquement froides. En conclusion, les cellules MD5, dérivées des animaux C57BL/6, constituent un modèle de cancer du sein à récepteurs hormonaux positifs de mauvais pronostic
Progress in breast cancer research relies on the availability of suitable cell lines that can be implanted in immunocompetent laboratory mice. The best explored mouse strain, C57Bl/6, is also the only one for which multiple genetic variants are available. Driven by the fact that no hormone receptor-positive C57Bl/6-derived mammary carcinoma cell lines are available, we decided to establish such cell lines. Breast cancers were induced in female C57BL/6 mice using a synthetic progesterone analogue combined with a DNA damaging agent. Cell lines were established from these tumors and selected for dual (estrogen + progesterone) receptor positivity, as well as transplantability into C57BL/6 females. One cell line, which we called MD5,fulfilled these criteria and allowed for the establishment of poorly differentiated, highly proliferative, immune cold tumors. Such tumors reduced their growth (though did not regress) upon treatment with estrogen receptor antagonists, as well as with anthracyline-based chemotherapy. However, the latter effect was not influenced by T cell depletion and MD tumors failed to respond to PD-1 blockade, suggesting that they are immunologically cold. In conclusion, C57BL/6-derived MD5 cells constitute a model of poor prognosis hormone receptor-positive breast cancer

Los estilos APA, Harvard, Vancouver, ISO, etc.

40

Piccolo, Marialuisa. "Preclinical development of anticancer Ru-based nanoaggregates in breast cancer models". Tesi di dottorato, 2017. http://www.fedoa.unina.it/12067/1/TesidottoratoML.pdf.

Texto completo

Resumen

Cancer, a growing health problem around the world, affects millions of people every year, so that innovative anticancer drugs with specific molecular mechanisms of action are essential in chemotherapeutic treatment to kill specific cancer types, and to overcome toxic side effects as well as chemoresistance. Impaired apoptosis and autophagy seem to play a central role in cancer development and constantly limit the efficacy of conventional cytotoxic therapies. Indeed, current research efforts are focused on a deeper understanding of the cellular response and/or resistance to anticancer treatments, including the role of cell death pathways activation by metallochemotherapeutics such as novel ruthenium-based drugs, proposed as safe and effective potential drugs. Moreover, in the last few years nanostructures have gained considerable interest for the safe delivery of therapeutic agents. In these fields, we have recently developed a novel approach for the in vivo delivery of novel Ru(III) complexes, preparing stable nucleolipidic-based formulations endowed with considerable antiproliferative activity. In particular, aiming at improving the suitability of Ru(III) complexes in biological environment - specifically of AziRu, a pyridine NAMI-A analog - as well as their advantages for biomedical applications, we have designed innovative nanoaggregates by means of high-functionalized nucleolipidic Ru(III) complexes, ad hoc mixed with zwitterionic or cationic lipids to provide stable and biocompatible liposome formulations for cancer therapy. Hence, in line with this project and by in vitro bioscreens in the frame of preclinical studies, we have focused on the ability of nucleolipidic ruthenium-containing liposomes to inhibit cancer proliferation in selected human breast cancer models in vitro, possibly by predisposing cells to programmed cell death. In the case, breast cancer is the second most common cancer worldwide after lung cancer, the fifth most common cause of cancer death, and the leading cause of cancer death in women. The global weight of breast cancer exceeds all other cancers and the incidence rates of breast cancer are increasing. Luckily, the total survival rates of most cancers have been prolonged due to the energies of both clinicians and scientists. Behind an in-depth microstructural characterization, we have herein demonstrated that the most efficient ruthenium-containing cationic nanoaggregates we have hitherto developed are able to elicit both extrinsic and intrinsic apoptosis, as well as autophagy. Using especially designed fluorescent formulations and confocal microscopy approaches for targeted studies of intracellular localization, in addition to subcellular fractionation and inductively coupled plasma-mass spectrometry (ICP-MS) to assess cellular accumulation, we have detected, unlike the naked AziRu, a wide both cytosolic and nuclear distribution of the active Ru(III) complex. This would allow the ruthenium to interact with both mitochondrial and nuclear molecular targets, accounting for its ability to inhibit breast cancer cell proliferation by the activation of multiple cell death pathways, possibly via mitochondrial perturbations involving Bcl-2 family members, and Ru(III) ions incorporation into double-stranded DNA. To limit chemoresistance and counteract uncontrolled proliferation, multiple cell death pathways activation is a promising strategy for targeted therapy development, especially in aggressive cancer diseases such as triple-negative breast cancer with limited treatment options. The heterogeneity of breast cancers makes them both a fascinating and difficult solid tumour to diagnose and treat. Triple-negative breast cancers in particular are difficult to define lacking Her2 expression, estrogen and progesterone receptor, and do not respond to hormonal therapies or Her2-targeted therapies; hence, new systemic therapies are desperately needed. The oncology community needs for a new dawn of innovative and creative means to overcome these challenges so we can witness further breakthroughs. Moreover, allowing for the importance of the tumour microenvironment as well as of the stromal components playing both critical role in the tumourigenic process, the function of cancer-associated immune cell system and their cellular secrets were also investigated, in order to achieve a deeper understanding of the typical molecular pathways involved in the cross-talk between tumour components and stromal cells; this would allow to properly act on tumour microenvironment in order to further improve the efficacy of chemotherapy. In this case, the EPO/ESA treatment – commonly used in therapy for anaemia – can induce tumour progression and growth, because of its impact on the anti-cancer immune response. So overall these outcomes discharge original knowledge in the field of anticancer therapy and on ruthenium-based candidate drugs, thus providing new insights for future optimized cancer treatment protocols.

Los estilos APA, Harvard, Vancouver, ISO, etc.

41

GRASSI, LUDOVICA. "Development of preclinical models for Renal Cell Carcinoma". Doctoral thesis, 2018. http://hdl.handle.net/11573/1086689.

Texto completo

Resumen

Renal Cell Carcinoma (RCC) is the most common form of kidney tumor, accounting for approximately 3% of all adult malignancies. To date, RCC is still a difficult disease to diagnose and treat. Although the surgery is the standard therapy for localized tumors, one quarter of patients who underwent nephrectomy, relapse within three years. Moreover, one third of patients arrives with metastases at diagnosis. Unfortunately, the metastatic disease is generally characterized by therapy resistance and very poor outcomes. So far, the lack of valid preclinical RCC models has hampered the discovery of valuable diagnostic and prognostic biomarkers and predictive indicators of therapy response for improving patients' management. In the project, we focused our efforts on the optimization of new patient-derived preclinical models for RCC. We first isolated heterogeneous undifferentiated cell populations responsible for tumor propagation and cancer therapy resistance. By performing a phosphoproteomic analysis we identified a protein signature predictive of cancer progression that would help to select patients more likely to relapse after surgery and who may benefit of adjuvant therapy. We then established an orthotopic patient-derived xenograft (PDX) model that faithfully recapitulate grading, histology and molecular characteristics of the parental tumors. The PDX model proved to be an indicator of bad prognosis and patient tumor could be propagated for up to seventh generation in mice. These findings support the possibility to use PDXs as a platform for patient monitoring and for drug testing. Finally, we were able to establish and characterize, for the first time, long term organoid cultures from normal and tumor samples. All together, these three new models provide innovative and valuable tools for RCC research, suggesting many potential applications for reproducing disease progression models, for biomarkers discovery and drug testing.

Los estilos APA, Harvard, Vancouver, ISO, etc.

42

Subashi, Ergys. "Dynamic Contrast-Enhanced MR Microscopy: Functional Imaging in Preclinical Models of Cancer". Diss., 2014. http://hdl.handle.net/10161/9068.

Texto completo

Resumen

Dynamic contrast-enhanced (DCE) MRI has been widely used as a quantitative imaging method for monitoring tumor response to therapy. The pharmacokinetic parameters derived from this technique have been used in more than 100 phase I trials and investigator led studies. The simultaneous challenges of increasing the temporal and spatial resolution, in a setting where the signal from the much smaller voxel is weaker, have made this MR technique difficult to implement in small-animal imaging. Existing preclinical DCE-MRI protocols acquire a limited number of slices resulting in potentially lost information in the third dimension. Furthermore, drug efficacy studies measuring the effect of an anti-angiogenic treatment, often compare the derived biomarkers on manually selected tumor regions or over the entire volume. These measurements include domains where the interpretation of the biomarkers may be unclear (such as in necrotic areas).

This dissertation describes and compares a family of four-dimensional (3D spatial + time), projection acquisition, keyhole-sampling strategies that support high spatial and temporal resolution. An interleaved 3D radial trajectory with a quasi-uniform distribution of points in k-space was used for sampling temporally resolved datasets. These volumes were reconstructed with three different k-space filters encompassing a range of possible keyhole strategies. The effect of k-space filtering on spatial and temporal resolution was studied in phantoms and in vivo. The statistical variation of the DCE-MRI measurement is analyzed by considering the fundamental sources of error in the MR signal intensity acquired with the spoiled gradient-echo (SPGR) pulse sequence. Finally, the technique was applied for measuring the extent of the opening of the blood-brain barrier in a mouse model of pediatric glioma and for identifying regions of therapeutic effect in a model of colorectal adenocarcinoma.

It is shown that 4D radial keyhole imaging does not degrade the system spatial and temporal resolution at a cost of 20-40% decrease in SNR. The time-dependent concentration of the contrast agent measured in vivo is within the theoretically predicted limits. The uncertainty in measuring the pharmacokinetic parameters with the sequences is of the same order, but always higher than, the uncertainty in measuring the pre-injection longitudinal relaxation time. The histogram of the time-to-peak provides useful knowledge about the spatial distribution of K^trans and microvascular density. Two regions with distinct kinetic parameters were identified when the TTP map from DCE-MRM was thresholded at 1000 sec. The effect of bevacizumab, as measured by a decrease in K^trans, was confined to one of these regions. DCE-MRI studies may contribute unique insights into the response of the tumor microenvironment to therapy.

Dissertation

Los estilos APA, Harvard, Vancouver, ISO, etc.

43

Monteiro, Maria Vinhas. "Development of biomimetic pancreatic cancer 3D in vitro models for preclinical drug screening". Master's thesis, 2020. http://hdl.handle.net/10773/30418.

Texto completo

Resumen

Pancreatic ductal adenocarcinoma (PDAC) is a disease with one of the highest mortality rates and with an increasing incidence worldwide. Currently, clinically administered therapies for the PDAC treatment are still extremely ineffective and of limited access. Given this scenario, it is urgent to investigate and validate new therapies for the treatment of this neoplasia. PDAC is a cancer with a unique stratified bio-architecture and characterized by an exacerbated desmoplastic reaction involving cancer-associated fibroblasts, immune cells and extracellular matrix proteins (ECM), which play a significant role in tumor progression and resistance to the currently used therapies in a clinical setting. The absence of cell-based in vitro models capable of reproducing the PDAC desmoplastic microenvironment and the histo-morphology results in a low correlation between the performance of new therapies in preclinical trials and that observed in controlled clinical trials. In this sense, three-dimensional (3D) in vitro tumor models emerge as a more suitable solution for preclinical evaluation when compared with the most frequently used two-dimensional (2D) cell cultures. 3D models represent more biomimetic models as they allow a more robust and realistic recapitulation of the tumor microenvironment, contributing to the discovery of new biomarkers and to the pre-clinical evaluation of new drugs in a more accurate way. Amongst currently developed 3D in vitro PDAC platforms, few are those that accurately recapitulate cell heterogeneity, tumor architecture and fibrotic stroma. To overcome these limitations, this dissertation focuses on bioengineering and characterization of a new 3D PDAC model, consisting of a biomimetic co-culture of pancreatic cancer cells (PANC-1) and cancer-associated fibroblasts (CAFs). This 3D model demonstrated to recapitulate the cellular components, their spatial distribution and resistance to pharmacological therapies in a similar way to that found in human tumors.
O adenocarcinoma ductal pancreático (ADP) é uma doença com uma das maiores taxas de mortalidade e com uma incidência crescente a nível mundial. Atualmente, as terapias administradas na clínica para o tratamento do ADP são ainda extremamente ineficazes e de acesso limitado. Perante este cenário torna-se urgente a investigação e validação de novas terapias para o tratamento desta neoplasia. O ADP é um cancro com uma bioarquitetura estratificada única e caracterizado por uma exacerbada reação desmoplásica envolvendo fibroblastos associados ao cancro, células imunes e proteínas da matriz extracelular (MEC), que desempenham um papel significativo na progressão tumoral e na resistência às terapias utilizadas atualmente em contexto clínico. A ausência de modelos de celulares capazes de reproduzir in vitro o microambiente desmoplásico e a histo-morfologia do ADP origina uma baixa correlação entre a performance de novas terapias obtida em ensaios pré-clínicos e aquela observada em ensaios clínicos controlados. Neste sentido, os modelos de tumores tridimensionais (3D) in vitro surgem como uma solução mais adequada para a avaliação pré-clínica quando comparados com as recomendadas culturas celulares bidimensionais 2D. Os modelos 3D representam modelos mais biomiméticos pois permitem recapitular de uma forma mais robusta e realista o microambiente tumoral, contribuindo para a descoberta de novos biomarcadores e para a avaliação pré-clínica de novos fármacos de uma forma mais precisa. Das plataformas 3D in vitro de ADP desenvolvidas atualmente, poucas são as que recapitulam de forma precisa a heterogeneidade celular, a arquitetura tumoral e o estroma fibrótico. Com o objetivo de colmatar estas limitações, a presente dissertação foca na bioengenharia e caracterização de um novo modelo 3D de ADP, consistindo numa co-cultura biomimética de células cancerígenas pancreáticas (PANC-1) e fibroblastos associados ao cancro (FACs). Este modelo 3D demonstrou recapitular os componentes celulares, a sua distribuição espacial e a resistência a terapias farmacológicas de uma forma semelhante à encontrada nos tumores humanos.
Mestrado em Biotecnologia

Los estilos APA, Harvard, Vancouver, ISO, etc.

44

CONCIATORI, FABIANA. "Genetic background dictates pro-angiogenic factor production in preclinical models of colorectal cancer". Doctoral thesis, 2018. http://hdl.handle.net/11573/1072173.

Texto completo

Resumen

Mutations such as BRAFV600E and PTEN-loss portend rapid tumor progression, treatment resistance, and overall impaired survival; on the other hand, tumor-stroma interactions are also a crucial determinant of tumor progression. Here we hypothesize that tumor genetic background may influence the surrounding microenvironment, through the production of chemokines and pro-angiogenic factors in ColoRectal Cancer (CRC) models. Here, we demonstrated that BRAFV600E, and to a lesser extent PTEN loss, were significantly associated with the production of higher levels of Interleukin (IL)-8 (p=0.004; p=0.05), whereas the other genetic alterations tested (RAS, PI3K) had no effect on IL-8 production. CRC cell lines BRAFV600E and PTEN-loss expressed the highest levels of IL-8 and a ROC curve-based prediction algorithm based on these two mutations had 68 % accuracy in predicting IL-8 production (p=0.002). On the other hand, IL-6 was almost never detected and Vascular Endothelial Growth Factor (VEGF) levels correlated with KRAS mutational status. Moreover, IL-8 is tightly controlled by activation of the MEK/ERK pathway, as MEK and ERK inhibitors profoundly suppressed its production regardless of the genetic background; the selective BRAF inhibitor downregulated IL-8 only in BRAFV600E contexts, but upregulated its production in parallel with ERK phosphorylation in BRAF-wt CRC cells. The PI3K/mTOR inhibitor had no effect on IL-8 production.

Los estilos APA, Harvard, Vancouver, ISO, etc.

45

BAZZICHETTO, CHIARA. "Tumor-stroma interactions influence the response to PI3K targeted agents in preclinical models of colorectal cancer (CRC)". Doctoral thesis, 2019. http://hdl.handle.net/11573/1244565.

Texto completo

Resumen

Introduction: One of the main obstacle to the successful development of therapeutic strategies remains the identification of biomarker underlying drug resistance. Recently, investigators have become more aware the role of the tumor microenvironment (TME) in cancer and the potential therapeutic opportunities that derive from suppressing potential resistance mechanisms arising microenvironmental interactions. The aim of this study was to set-up multicellular culture models to uncover the molecular mechanisms by which stromal/endothelial cells modulate response to signaling inhibitors and to identify potential therapeutic targets in PTEN-loss contexts. Methods and Materials: Isogenic CRC cell lines (X-MAN™ HCT116 and HCT116 PTEN-/-) were treated with MAPKi and PI3K/mTORi alone or in combination, in the presence or absence of stromal fibroblasts or fibroblast/endothelial cell conditioned medium (CM). Cytofluorimetric analysis and Crystal Violet assay were used to analyse functional response to targeted agents; pathways activation and cytokine/chemokine profile were analysed using Western blot and ELISA assay respectively. Results and Discussion: In co-culture CRC models, the response to MAPK and PI3K inhibitors is the result of interaction between tumor cells and their surrounding stroma. The response to PI3K/mTORi is mainly influenced by microenvironmental interactions: direct cell-to-cell tumor/stroma contact renders stromal cells resistant to PI3K/mTORi, while the presence of stromal cell-derived soluble factors sensitizes PTEN-competent CRC cells to PI3K/mTORi-mediated growth inhibition. This effect was confirmed using CM from different types of stromal cells (fibroblast/endothelial) that similarly affected the response of CRC cell lines to signalling inhibitors; this is probably due to similar profile of cytokine/chemokine production in stromal cell and is subjected to a “saturation” effect. The presence of stromal CM upregulates MAPK activation regardless of PTEN status, whereas mTOR pathway upregulation is observed mainly in PTEN-competent CRC cellsin PTEN-competent cells soluble factors released by stromal elements paradoxically impair PTEN function, leading to downstream mTORC1 complex formation and pathway activation. This paradoxical mTORC1 activation upon exposure to stroma-derived soluble factors results in functional hypersensitivity of PTEN-competent CRC cells to the growth inhibitory effects of double PI3K/mTOR inhibitors. . Conclusions: The presence of stromal cells (fibroblasts/endothelium) profoundly influences CRC response to PI3K/mTOR-targeting agents. Understanding the mechanisms underlying microenvironmental interactions (tumor, stroma, soluble factors) may be of fundamental importance to overcome therapeutic resistance and develop more effective therapies for patients affected by cancer.

Los estilos APA, Harvard, Vancouver, ISO, etc.

46

Hussain, Nosheen, David Connah, Hassan Ugail, Patricia A. Cooper, Robert A. Falconer, Laurence H. Patterson y Steven D. Shnyder. "The use of thermographic imaging to evaluate therapeutic response in human tumour xenograft models". 2016. http://hdl.handle.net/10454/8781.

Texto completo

Resumen

Yes
Non-invasive methods to monitor tumour growth are an important goal in cancer drug development. Thermographic imaging systems offer potential in this area, since a change in temperature is known to be induced due to changes within the tumour microenvironment. This study demonstrates that this imaging modality can be applied to a broad range of tumour xenografts and also, for the first time, the methodology’s suitability to assess anti-cancer agent efficacy. Mice bearing subcutaneously implanted H460 lung cancer xenografts were treated with a novel vascular disrupting agent, ICT-2552, and the cytotoxin doxorubicin. The effects on tumour temperature were assessed using thermographic imaging over the first 6 hours post-administration and subsequently a further 7 days. For ICT-2552 a significant initial temperature drop was observed, whilst for both agents a significant temperature drop was seen compared to controls over the longer time period. Thus thermographic imaging can detect functional differences (manifesting as temperature reductions) in the tumour response to these anti-cancer agents compared to controls. Importantly, these effects can be detected in the first few hours following treatment and therefore the tumour is observable non-invasively. As discussed, this technique will have considerable 3Rs benefits in terms of reduction and refinement of animal use.
University of Bradford

Los estilos APA, Harvard, Vancouver, ISO, etc.

47

Brodeur, Melica. "Predictive carboplatin treatment response models for epithelial ovarian cancer : comparison of 2D, 3D and in-vivo models". Thesis, 2021. http://hdl.handle.net/1866/25659.

Texto completo

Resumen

L’adénocarcinome épithélial de l’ovaire (CEO) est le cancer gynécologique le plus mortel. La recherche de nouvelles thérapies repose principalement sur des modèles précliniques 2D et in vivo avec des lignées cellulaires (LC) pour générer les évidences nécessaires à l’initiation d’essais cliniques. Ce processus requiert des fonds substantiels en recherche/santé qui est associé à un taux d’attrition élevé laissant supposer des lacunes dans le modèle actuel. Nos publications antérieures suggèrent que la sensibilité in vitro de nos LC du CEO à la chimiothérapie carboplatin varie en 2D ou 3D. Il reste à élucider lequel de ces modèles est le plus représentatif de la réponse in vivo. De ce fait, nous avons émis l’hypothèse que le modèle 3D refléterait plus étroitement la sensibilité in vivo. L’objectif de cette étude était de caractériser la réponse au carboplatin de nos LC du CEO en monocouches et en sphéroïdes (3D), puis de les comparer à leur réponse in vivo (xénogreffes). Un total de 6 LC du CEO a été injecté dans des souris qui ont reçues trois différentes concentrations de carboplatin. Leurs réponses ont été évaluées/classées selon leurs mesures de volume tumoral et l’immunofluorescence. Ces mêmes LC ont été ensemencées dans des plaques à très faible adhérence pour former des sphéroïdes et les traiter. Des analyses de cytométrie en flux ont été effectuées afin de classer les LC selon leur concentration inhibitrice médiane (CI50). Nous avons comparé le tout aux résultats 2D (CI50) précédemment publiés. Nos résultats montrent que le système 3D démontre la meilleure concordance avec le modèle in vivo. Notamment, notre LC ultra-résistance en 2D devient plus sensible en modèle murin ou encore en 3D. Inversement, une LC ultra-sensible en 2D est plus résistante en xénogreffe et en sphéroïde. Les résultats découlant de notre étude sont importants à considérer lors d’investissement de temps et de fonds dans les études de criblage et de prédiction de réponses thérapeutiques.
Epithelial ovarian adenocarcinoma (EOC) is the most lethal gynecological cancer. The drug discovery pipeline is heavily based on preclinical models. Typically, 2D cell line (CL)-based models are used to screen compounds followed by validation in animal models to generate the evidence needed to design clinical trials. This process incurs a high cost to the research pipeline and still results in high drug attrition rates. This may in part reflect the poor translation of preclinical to clinical results and points to deficiencies in modeling. Previous work from our laboratory shows that the sensitivity of our EOC CLs to carboplatin therapy varies between 2D and 3D in vitro models, however it is unclear how these differences align with the in vivo response. We hypothesize that 3D models will more closely reflect therapeutic in vivo response. The objective of this study was to characterize the carboplatin sensitivity of EOC CLs in 2D and 3D-spheroids and compare them to in vivo response using mouse xenografts. We injected mice with 6 different EOC CLs that were treated with 3 different carboplatin concentrations. Tumor volume measurements and immunofluorescence viability stains were used to categorize CLs by their sensitivity. The same CLs were seeded in low attachment plates to form, and thereafter treat, spheroids. Flow cytometry analysis was used to classify CLs by their 50% inhibitory response (IC50). The 2D response (IC50) for these CLs has previously been published. Our results show that therapeutic response changes significantly for a single CL between different systems, and the 3D model was most concordant with the in vivo model. Our ultra-resistant CL in 2D became more sensitive in 3D/mouse models. In contrast, the highly 2D sensitive CL became more resistant in our xenograft/spheroid models. The results are important to consider when investing time/funds in drug screening and therapeutic response prediction studies.

Los estilos APA, Harvard, Vancouver, ISO, etc.

48

Gkountakos, Anastasios. "Assessing the potential role of Rictor expression as predictive factor of response to PI3K/mTOR pathway inhibitors in preclinical models of squamous cell lung cancer". Doctoral thesis, 2020. http://hdl.handle.net/11562/1017793.

Texto completo

Resumen

Squamous cell lung cancer (SQLC) is the second most prevalent histologic type of lung cancer and accounting for approximately 30% of newly diagnosed non-small cell lung cancer (NSCLC) cases. Systemic treatments for SQLC patients include cytotoxic chemotherapy and immune-oncology approaches. In contrast with lung adenocarcinoma, which is the other main subtype of NSCLC, no patient-tailored treatments are available so far for SQLC. Accumulating evidence suggests that the PI3K/mTOR axis is one of the most frequently altered pathways in SQLC. However, despite a plethora of clinical trials with numerous PI3K/mTOR targeted inhibitors, no significant increase in patients’ survival has been observed as compared to standard treatment options. A possible explanation for the outcome of those clinical trials might be the lack of reliable predictive biomarkers for better patients’ stratification. We and others have reported Rictor copy number gain (CNG) in a set of SQLC patients by performing targeted DNA sequencing on archival tissues. Another group has suggested the existence of Rictor focal amplification in subsets of lung cancers, including SQLC, and further suggested Rictor as a potential predictive biomarker of response to targeted therapy. However, no conclusive data were presented to show that Rictor amplification is driving activation of the PI3K/mTOR pathway in SQLC cells or representing a valid biomarker predictive of response to targeted inhibition of the pathway. Here, we used three different SQLC cell lines and 60 tissue specimens to show that CNG of Rictor is a recurrent event in SQLC, yet this is due to the polysomy of the short arm of chromosome 5 rather than to focal amplification. All three cell lines tested showed different Rictor CNG and different levels of its transcript and protein. In particular, the SQLC cell line harboring the higher CNG (H-1869) accordingly displayed higher level of Rictor protein. Therefore, we sought to test the possibility that the dosage of Rictor might affect the activation of PI3K/mTOR pathway and sensitivity towards its targeting agents. Unexpectedly, we found that Rictor levels did not parallel the biochemical activation of the pathway nor the sensitivity to dual mTORC1/C2 or PI3K/mTOR inhibitions. These observations were confirmed by genetic perturbation analysis, as reduction of Rictor levels through RNA interference did not lead neither to reduced cell viability nor to significant changes in drug sensitivity in the two cell lines tested. Overall, our findings suggest that Rictor does not represent a predictive biomarker of response towards PI3K/mTOR directed therapy.

Los estilos APA, Harvard, Vancouver, ISO, etc.

49

Phatak, Amruta Rajendra. "Modeling cancer predisposition: Profiling Li-Fraumeni syndrome patient-derived cell lines using bioinformatics and three-dimensional culture models". 2015. http://hdl.handle.net/1805/8037.

Texto completo

Resumen

Indiana University-Purdue University Indianapolis (IUPUI)
Although rare, classification of over 200 hereditary cancer susceptibility syndromes accounting for ~5-10% of cancer incidence has enabled the discovery and understanding of cancer predisposition genes that are also frequently mutated in sporadic cancers. The need to prevent or delay invasive cancer can partly be addressed by characterization of cells derived from healthy individuals predisposed to cancer due to inherited "single-hits" in genes in order to develop patient-derived samples as preclinical models for mechanistic in vitro studies. Here, we present microarray-based transcriptome profiling of Li-Fraumeni syndrome (LFS) patient-derived unaffected breast epithelial cells and their phenotypic characterization as in vitro three-dimensional (3D) models to test pharmacological agents. In this study, the epithelial cells derived from the unaffected breast tissue of a LFS patient were cultured and progressed from non-neoplastic to a malignant stage by successive immortalization and transformation steps followed by growth in athymic mice. These cell lines exhibited distinct transcriptomic profiles and were readily distinguishable based upon their gene expression patterns, growth characteristics in monolayer and in vitro 3D cultures. Transcriptional changes in the epithelial-to-mesenchymal transition gene signature contributed to the unique phenotypes observed in 3D culture for each cell line of the progression series; the fully transformed LFS cells exhibited invasive processes in 3D culture with disorganized morphologies due to cell-cell miscommunication, as seen in breast cancer. Bioinformatics analysis of the deregulated genes and pathways showed inherent differences between these cell lines and targets for pharmacological agents. After treatment with small molecule APR-246 that restores normal function to mutant p53, we observed that the neoplastic LFS cells had reduced malignant invasive structure formation from 73% to 9%, as well as an observance of an increase in formation of well-organized structures in 3D culture (from 27% to 91%) by stereomicroscopy and confocal microscopy. Therefore, the use of well-characterized and physiologically relevant preclinical models in conjunction with transcriptomic profiling of high-risk patient derived samples as a renewable laboratory resource can potentially guide the development of safer and more effective chemopreventive approaches.

Los estilos APA, Harvard, Vancouver, ISO, etc.

50

伊藤, 友一 y Yuichi Ito. "Characterization of a novel lymph node metastasis model from human colonic cancer and its preclinical use for comparison of anti-metastatic efficacy between oral S-1 and UFT/LV". Thesis, 2013. http://hdl.handle.net/2237/19163.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Tesis sobre el tema "Preclinical cancer models"

Crea una cita precisa en los estilos APA, MLA, Chicago, Harvard y otros