In this thesis, the theory of poroelasticity, namely the Mixture Theory version -- a homogenized, macroscopic scale approach used to describe fluid flow through a porous medium -- is employed in three separate cases pertaining to a biological phenomenon. The first investigation explores the behavior of interstitial fluid pressure (IFP) in solid tumors. Thus, in Chapter 2, a Mixture Theory based approach is developed to describe the evolution of the IFP from that in a healthy interstitium to the elevated levels in cancerous tumors. Attention is focused on angiogenesis, a tightly regulated process in healthy tissue that provides all necessary nutrients through the creation of new blood vessels. Once this process becomes unruly within a tumor, angiogenesis gives rise to an abnormal vasculature by forming convoluted and leaky blood vessels. Thus, the primary focus of the model is on the capillary filtration coefficient and vascular density as they increase in time, which in turn elevates the tumor IFP. Later, the Mixture Theory model is extended to simulate the effects of vascular normalization, where the cancer therapy not only prunes blood vessels, but reverts the chaotic vasculature to a somewhat normal state, thereby temporarily lowering the tumor IFP. In Chapter 3, the validity of an assumption that was made in order to facilitate the mathematical calculations is investigated. In addition to all of the Mixture Theory assumptions, it is assumed that the pore pressure p is proportional to the tissue dilatation e. This assumption is examined to determine how appropriate and accurate it is, by using a heat type equation without the presence of sources and sinks under the assumption of a spherical geometry. The results obtained under the proportionality of p and e, are compared with the results obtained without this assumption. A substantial difference is found, which suggests that great care must be exercised in assuming the proportionality of p and e. The last application is reported in Chapter 4 and it investigates the pathogenesis of normal pressure hydrocephalus. In a normal brain, cerebrospinal fluid (CSF) is created by the choroid plexus, circulates around the brain and the spinal cord without any impediment, and then is absorbed at various sites. However, normal pressure hydrocephalus occurs when there is an imbalance between the production and absorption of CSF in the brain that causes the impaired clearance of CSF and the enlargement of ventricles; however, the ventricular pressure in this case is frequently measured to be normal. Thus, a mathematical model using Mixture Theory is formulated to analyze a possible explanation of this brain condition. Levine (1999) proposed the hypothesis that CSF seeps from the ventricular space into the brain parenchyma and is efficiently absorbed in the bloodstream. To test this hypothesis, Levine used the consolidation theory version of poroelasticity theory, with the addition of Starling's law to account for the absorption of CSF in the brain parenchyma at steady state. However, the Mixture Theory model does not agree with the results obtained by Levine (1999) which leads one to conclude that the pathogenesis of normal pressure hydrocephalus remains unknown. To conclude the thesis, all three applications of Mixture Theory are discussed and the importance and contribution of this work is highlighted. In addition, possible future directions are indicated based on the findings of this thesis.

Yes / Currently, out of the 82 US FDA-approved targeted therapies for adult cancer treatments, only three are approved for use in children irrespective of their genomic status. Apart from leukemia, only a handful of genomic-based trials involving children with solid tumors are ongoing. Emerging genomic data for pediatric solid tumors may facilitate the development of precision medicine in pediatric patients. Here, we provide an up-to-date review of all reported genomic aberrations in the eight most common pediatric solid tumors with whole-exome sequencing or whole-genome sequencing data (from cBioPortal database, Pediatric Cancer Genome Project, Therapeutically Applicable Research to Generate Effective Treatments) and additional non-whole-exome sequencing studies. Potential druggable events are highlighted and discussed so as to facilitate preclinical and clinical research in this area. / Seed Grant of Strategic Research Theme for Cancer, The University of Hong Kong of AKSC. VWY Lui is funded by the Research Grant Council, Hong Kong (#17114814, #17121616, General Research Fund; T12–401/13-R, Theme-based Research Scheme), and the Start-up Fund, School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong. W Piao is funded by the Faculty Postdoctoral Fellowship Scheme, Faculty of Medicine, the Chinese University of Hong Kong.

abstract: The rate of progress in improving survival of patients with solid tumors is slow due to late stage diagnosis and poor tumor characterization processes that fail to effectively reflect the nature of tumor before treatment or the subsequent change in its dynamics because of treatment. Further advancement of targeted therapies relies on advancements in biomarker research. In the context of solid tumors, bio-specimen samples such as biopsies serve as the main source of biomarkers used in the treatment and monitoring of cancer, even though biopsy samples are susceptible to sampling error and more importantly, are local and offer a narrow temporal scope. Because of its established role in cancer care and its non-invasive nature imaging offers the potential to complement the findings of cancer biology. Over the past decade, a compelling body of literature has emerged suggesting a more pivotal role for imaging in the diagnosis, prognosis, and monitoring of diseases. These advances have facilitated the rise of an emerging practice known as Radiomics: the extraction and analysis of large numbers of quantitative features from medical images to improve disease characterization and prediction of outcome. It has been suggested that radiomics can contribute to biomarker discovery by detecting imaging traits that are complementary or interchangeable with other markers. This thesis seeks further advancement of imaging biomarker discovery. This research unfolds over two aims: I) developing a comprehensive methodological pipeline for converting diagnostic imaging data into mineable sources of information, and II) investigating the utility of imaging data in clinical diagnostic applications. Four validation studies were conducted using the radiomics pipeline developed in aim I. These studies had the following goals: (1 distinguishing between benign and malignant head and neck lesions (2) differentiating benign and malignant breast cancers, (3) predicting the status of Human Papillomavirus in head and neck cancers, and (4) predicting neuropsychological performances as they relate to Alzheimer’s disease progression. The long-term objective of this thesis is to improve patient outcome and survival by facilitating incorporation of routine care imaging data into decision making processes. / Dissertation/Thesis / Doctoral Dissertation Biomedical Informatics 2017

Made available in DSpace on 2014-06-11T19:23:07Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-04-01Bitstream added on 2014-06-13T20:29:57Z : No. of bitstreams: 1 oliveira_ct_me_botfm.pdf: 2586546 bytes, checksum: 0fa98dd82d7160414a5cffb84658a089 (MD5) / Fundação Amaral Carvalho / A infiltração de MO por tumores não-hematológicos tem sido descrita desde 1935 e, mais recentemente, desperta interesse da comunidade científica, pois inúmeros trabalhos têm relacionado a presença de células tumorais na MO com o processo de carcinogênese e a progressão tumoral. O presente estudo teve por objetivo o levantamento dos casos com diagnóstico de mielopatia infiltrativa por tumores nãohematológicos, provenientes da Faculdade de Medicina de Botucatu – UNESP e do Hospital Amaral Carvalho – Jaú, avaliados, retrospectivamente, no período de 1998 a 2008 (num universo de 15.191 coletas de MO). Incluímos 193 pacientes, dos quais 171 eram adultos e 22 crianças (idade ≤ 21 anos), com paridade entre os sexos (1:1) e mediana de idade de 55 anos. Foram analisados dados clínicos, diagnóstico e estadiamento do tumor primário, sítios de metástases, características laboratoriais (hemograma e marcadores tumorais séricos), características da MO, tratamento e a relação desses fatores com a sobrevida dos pacientes, através do programa de estatística SPSS®. Os resultados encontrados apontam que os tumores que mais frequentemente infiltraram a MO nos adultos foram: tumores de mama, próstata e sítio primário indeterminado, e neuroblastoma nas crianças. A análise da MO revelou positividade de 80% para mielograma e BMO, e presença de fibrose em 32% dos pacientes (40%, quando associados a áreas de necrose no mesmo material). Na avaliação hematológica observamos: anemia, alteração de leucócitos e plaquetopenia. Houve diferença, estatisticamente significante, com maior mediana de sobrevida global (p= 0,000) para pacientes do sexo feminino, portadores de adenocarcinoma de mama, em estádios iniciais e que receberam algum tipo de tratamento (quimio, radio e/ou hormonioterapia). Na análise de sobrevida, a partir do diagnóstico de mielopatia infiltrativa, houve... / Bone marrow (BM) infiltration by nonhematopoietic tumors has been described since 1935, and a increased number of papers about this topic have been published. Some of the studies have related the relationship between the presence of peripheral circulating tumors cells, bone marrow infiltration, carcinogenesis and tumor progression. This study has, as essential objective, the evaluation of infiltrative mielopathy by nonhematopoietic tumors from Faculdade de Medicina de Botucatu - UNESP and Hospital Amaral Carvalho – Jaú. Data were analised retrospectively from 1998 January to 2008 August (15.191 bone marrow samples). We have included 193 patients. One hundred seventy one were adults and 22 were children (considered age ≤ 21 years), with similar number of patients by gender, and median age 55 years. Medical records from the selected patients were analised, with focus on clinical aspects, primary site of tumor, initial stage, metastatic sites, hematologic and bone marrow features, treatment and the relationship between this data and survival. Results have demonstrated that most frequent solid tumors in adults were breast cancer, prostate cancer and undetermined primary site, and neuroblastoma among children. Bone marrow revealed infiltration in 80% of samples by myelogram and BM biopsy, and fibrosis in 32% (40% when associated with necrosis area). We observed anaemia, leukocyte alterations and thrombocytopenia as hematologic features. There were significant differences in global survival, wich was better among female patients, diagnosis of breast cancer, initial clinical stages and who has received any type of treatment (chemotherapy, radiotherapy and/or hormoniotherapy). When we analised survival since diagnosis of infiltrative mielopathy, adult patients with leucoeritroblastic reaction and trombocytopenia, and undetermined primary site tumors, melanoma or gastrointestinal tumors had... (Complete abstract click electronic access below)

Intravenously delivered cancer drugs face transport limitations at the tumor site and cannot reach all parts of tumors at therapeutically effective concentrations. Transport limitations also prevent oxygen from distributing evenly in tumors resulting in hypoxia, which plays a critical role in cancer progression. In this dissertation, I present the development of micro-devices that mimic transport limitations of drugs and nutrients on three dimensional tumor tissues, enable visualization and quantification of the ensuing gradients, and enable simple analysis and mathematical modeling of obtained data. To measure the independent effects of oxygen gradients on tumor tissues, an oxygen delivery device that used microelectrodes to generate oxygen directly underneath three-dimensional tumor cylindroids was developed. Supplying oxygen for 60 hours eliminated the necrotic region typically found in the center of cylindroids. Dead cells were observed moving away from the location of oxygen delivery. These measurements show that oxygen gradients are an important determinant of cell viability and rearrangement. Another micro-device was developed to mimic the delivery and systemic clearance of therapeutic agents. This microfluidic device consisted of cuboidal tumor tissue subjected to continuous medium perfusion along one face. The device was used to measure the spatiotemporal dynamics of the accumulation of therapeutic bacteria in tumors. Suspensions of Salmonella typhimurium and Escherichia coli strains were delivered to tumor tissues for 1 hour. Bacterial motility strongly correlated (R2 = 99.3%) with the extent of tissue accumulation. Based on spatio-temporal profiles and a mathematical model of motility and growth, bacterial dispersion was found to be necessary for deep penetration into tissue. These results show that motility is critical for effective distribution of bacteria in tumors. The microfluidic device was further used to mimic the delivery and clearance of equal concentrations of doxorubicin and liposome-encapsulated doxorubicin (Doxil). A pharmacokinetic/pharmacodynamic model incorporating mechanisms of tissue-level diffusion and binding was developed and experimental data was fit to this model. Doxorubicin was found to have the optimal diffusivity and binding for maximizing therapeutic effect. Doxil was severely limited by low intratumor drug release. These results show that in-vitro models mimicking tissue-level transport limitations more accurately predict the therapeutic response of drugs.

No description available.

Orientador: Lígia Niero-Melo / Banca: Lucilene Silva Ruiz e Rezende / Banca: Eduardo Moreira de Queiroga / Resumo: A infiltração de MO por tumores não-hematológicos tem sido descrita desde 1935 e, mais recentemente, desperta interesse da comunidade científica, pois inúmeros trabalhos têm relacionado a presença de células tumorais na MO com o processo de carcinogênese e a progressão tumoral. O presente estudo teve por objetivo o levantamento dos casos com diagnóstico de mielopatia infiltrativa por tumores nãohematológicos, provenientes da Faculdade de Medicina de Botucatu - UNESP e do Hospital Amaral Carvalho - Jaú, avaliados, retrospectivamente, no período de 1998 a 2008 (num universo de 15.191 coletas de MO). Incluímos 193 pacientes, dos quais 171 eram adultos e 22 crianças (idade ≤ 21 anos), com paridade entre os sexos (1:1) e mediana de idade de 55 anos. Foram analisados dados clínicos, diagnóstico e estadiamento do tumor primário, sítios de metástases, características laboratoriais (hemograma e marcadores tumorais séricos), características da MO, tratamento e a relação desses fatores com a sobrevida dos pacientes, através do programa de estatística SPSS®. Os resultados encontrados apontam que os tumores que mais frequentemente infiltraram a MO nos adultos foram: tumores de mama, próstata e sítio primário indeterminado, e neuroblastoma nas crianças. A análise da MO revelou positividade de 80% para mielograma e BMO, e presença de fibrose em 32% dos pacientes (40%, quando associados a áreas de necrose no mesmo material). Na avaliação hematológica observamos: anemia, alteração de leucócitos e plaquetopenia. Houve diferença, estatisticamente significante, com maior mediana de sobrevida global (p= 0,000) para pacientes do sexo feminino, portadores de adenocarcinoma de mama, em estádios iniciais e que receberam algum tipo de tratamento (quimio, radio e/ou hormonioterapia). Na análise de sobrevida, a partir do diagnóstico de mielopatia infiltrativa, houve... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Bone marrow (BM) infiltration by nonhematopoietic tumors has been described since 1935, and a increased number of papers about this topic have been published. Some of the studies have related the relationship between the presence of peripheral circulating tumors cells, bone marrow infiltration, carcinogenesis and tumor progression. This study has, as essential objective, the evaluation of infiltrative mielopathy by nonhematopoietic tumors from Faculdade de Medicina de Botucatu - UNESP and Hospital Amaral Carvalho - Jaú. Data were analised retrospectively from 1998 January to 2008 August (15.191 bone marrow samples). We have included 193 patients. One hundred seventy one were adults and 22 were children (considered age ≤ 21 years), with similar number of patients by gender, and median age 55 years. Medical records from the selected patients were analised, with focus on clinical aspects, primary site of tumor, initial stage, metastatic sites, hematologic and bone marrow features, treatment and the relationship between this data and survival. Results have demonstrated that most frequent solid tumors in adults were breast cancer, prostate cancer and undetermined primary site, and neuroblastoma among children. Bone marrow revealed infiltration in 80% of samples by myelogram and BM biopsy, and fibrosis in 32% (40% when associated with necrosis area). We observed anaemia, leukocyte alterations and thrombocytopenia as hematologic features. There were significant differences in global survival, wich was better among female patients, diagnosis of breast cancer, initial clinical stages and who has received any type of treatment (chemotherapy, radiotherapy and/or hormoniotherapy). When we analised survival since diagnosis of infiltrative mielopathy, adult patients with leucoeritroblastic reaction and trombocytopenia, and undetermined primary site tumors, melanoma or gastrointestinal tumors had... (Complete abstract click electronic access below) / Mestre

The majority of human cancers arise due to cells inabitily to maintain genomic stability. Cytogenetic changes (especially chromosomal aberrations) in peripheral blood lymphocytes which reflect not only the individual exposure to genotoxic factors, but also individual sensitivity to genotoxic effect and the tumor is late consequence to genotoxic effect. Summary epidemiological prospective studies over the last ten years have shown that increased level of chromosomal aberrations in peripheral blood lymphocytes is predictive of cancer risk. This thesis is focused on the detection of particular types of chromosomal damage in patients with choosed types of newly diagnosed cancers compared to healthy control persons. We cytogenetically analyzed 100 patients with colorectal cancer and 298 controls and 123 patients with breast cancer and 123 controls - healthy women. We compared the percentage of aberrant cells, the percentage of total aberrations, the percentages of chromatid and chromosome aberrations found in patients with both types of tumors and in controls and we verified the predictive value of chromosomal aberrations as a biomarker of cancer risk. In patients with colorectal cancer was statistically significantly increased only the level of chromatid aberrations (CHTA) (1,45±1,28) compared to...

In der vorliegenden Arbeit wird gezeigt, daß der physiologische Östrogenmetabolit 2-Methoxyestradiol (2-ME) eine sehr starke Wachstumshemmung auf Tumorzellen verschiedener solider Tumoren ausübt. Die untersuchten Tumoren sind das hepatozelluläre Karzinom (HCC), das Pankreaskarzinom und das Bronchialkarzinom. Alle drei Tumoren haben eine sehr schlechte Prognose, die sich in den letzten 20 Jahren trotz neuer OP-Techniken und neuer zytostatisch wirkender Substanzen sowie molekularer Therapieansätze nicht wesentlich verbessert hat. Beim HCC und beim Pankreaskarzinom konnten wir durch die Verwendung mehrerer Zelllinien eine Generalisierbarkeit der gefundenen Ergebnisse dokumentieren, denn es kam zu einer dosisabhängigen Wachstumshemmung von bis zu 90% bei allen bis auf eine Pankreaskarzinomzelllinie. Die Wirkung lies sich noch verstärken, indem wir 2-ME beim Pankreaskarzinom mit in der Klinik üblichen Zytostatika wie Gemcitabine, Docetaxel oder einem monoklonalen Antikörper gegen den EGF Rezeptor kombinierten. Wir fanden eine additive Wachstumshemmung in der Kombination mit allen verwendeten Substanzen. Beim Bronchialkarzinom basierten unsere Untersuchungen auf Vorarbeiten, bei denen bereits ein tumorhemmender Effekt durch 2-ME gefunden wurde. Wir kombinierten 2-ME mit Gentherapie. Dazu setzten wir ein Adenovirus, welches das Tumorsuppressorgen p53 exprimiert, ein. Hier konnten wir zeigen, daß das vom Gen des Adenovirus stammende p53 Protein nach systemischer intravenöser Applikation in den Lungenmetastasen exprimiert werden kann. 2-ME stabilisierte dieses p53 Protein, so daß eine ausreichende Menge funktionsfähigen p53 Proteins vorhanden war, um die Tumorzellen zu töten oder im Wachstum zu hemmen. Dies war der erste Bericht über eine erfolgreiche intravenöse Applikation eines adenoviralen Vektors mit einem Tumorsuppressorgen. 2-ME war nicht nur in der Lage, wachstumshemmend auf normale Tumorzellen zu wirken. Wir konnten auch zeigen, daß multiresistente Pankreaskarzinomzellen, die eine bis zu 1000-fach letale Dosis Zytostatika überleben, komplett sensibel gegenüber 2-ME waren. Die Wachstumshemmung durch 2-ME war in diesem Versuch identisch zwischen parentalen sensiblen Zellen und den multiresistenten Zellen. Die IC50 lag hier bei 0,56mM bzw bei 1,65mM je nachdem, ob das mdr-1 Gen exprimiert wurde oder nicht. Diese Werte entsprechen in etwa denen, die bei anderen Tumorzelltypen gefunden wurden. Auch Bronchialkarzinomzellen, die eine Resistenz gegen Cisplatin aufwiesen, zeigten sich ebenfalls komplett sensibel gegenüber 2-ME. Untersuchungen zur Toxizität von 2-ME zeigten, daß Kulturen von normalen humanen Hepatozyten, die von Leberresektaten gewonnen wurden, die Behandlung mit 2-ME überlebten. In parallelen Versuchen mit HCC Zellen zeigte sich eine signifikante Wachstumshemmung der Tumorzellen. Da die normalen Hepatozyten nicht proliferieren, untersuchten wir proliferierende Hepatozyten, indem wir Leberresektionen bei Mäusen durchführten. In der Leberregenerationssphase behandelten wir die Mäuse mit 2-ME. 2-ME hatte keine nachteilige Wirkung auf die Tiere. Nach Beendigung des Versuches waren die resezierten Lebern fast komplett regeneriert. Immunhistochemische Untersuchungen konnten zeigen, daß die Anzahl der apoptotischen Zellen in der regenerierenden Leber in der mit 2-ME behandelten Gruppe nicht zunahm. Durch eine Färbung mit PCNA konnte die Proliferation der Hepatozyten nach Resektion und damit die Regeneration verdeutlicht werden. Hier war die Proliferationsrate unabhängig von der Behandlung mit 2-ME. Als wesentlichen Mechanismus der Wachstumshemmung von Tumorzellen durch 2-ME fanden wir die starke Induktion von Apoptose in allen Zellen, bis auf die relativ resistente Pankreaskarzinomzelllinie PaTu 8988s. Mit mehreren Untersuchungstechniken konnten wir die Apoptose nachweisen. Um die Mechanismen der Apoptoseinduktion zu untersuchen, führten wir Western Blot Untersuchungen durch, die Veränderungen des Expressionsmusters apoptosebezogener Proteine aufzeigen sollten. Wir fanden eine Induktion des p53 Proteins in den HCC Zelllinien, die den Wild-Typ p53 exprimieren. Die Pankreaskarzinomzellen waren alle mutiert für das p53 Gen, so daß hier nach 2-ME Behandlung p53 unabhängige Apoptose vorlag. Messungen des p21 Proteins, einem direkten Effektor von p53, zeigte, daß es parallel zu p53 hochreguliert wurde, was darauf schließen läßt, daß das hochregulierte p53 funktionell aktiv ist. In einer Zelllinie (SK-Hep 1) wurde das stärkste Antiapoptoseprotein bcl-2 herunterreguliert, was eine Förderung der Apoptoseinduktion nach sich zieht. Somit führen mehrere Mechanismen zum apoptotischen Zelltod. Tierversuche an Nacktmäusen zeigten nicht nur, daß 2-ME Tumorzellen töten kann, sondern lassen auch Rückschlüsse für eine klinische Anwendung zu. So konnten wir zeigen, daß subcutane HCC Tumoren zu 55% und Lungenmetastasen von Pankreaskarzinomen und Bronchialkarzinomen um 59, bzw. 55% im Wachstum gehemmt werden konnten. Die Kombination mit dem p53 tragenden Adenovirus verringerte die Tumormasse um weitere 14%. Die gesamte Tumormasse konnte durch diese Kombination um das 336-fache gegenüber der Kontrollgruppe reduziert werden. Den beschriebenen antiangiogenetischen Effekt konnten wir weder beim Pankreaskarzinom, noch beim Bronchialkarzinom nachvollziehen. Die Tiere zeigten keinerlei klinisch apparente Nebenwirkungen wie Durchfall, Gewichtsverlust, Bewegungsarmut oder anderes. Die Kontrollgruppe der Tiere mit Lungenmetastasen vom Pankreaskarzinom hingegen zeigte eine deutliche Tumorkachexie mit 20%igem Gewichtsverlust im Vergleich zur Therapiegruppe. Schlußfolgernd ist 2-ME eine Substanz, die von großem klinischen Interesse ist. Durch die hohe Wirksamkeit in vitro und in vivo bei gleichzeitig sehr geringen Nebenwirkungen wird sie derzeit in der Klinik in Phase I/II Studien getestet. Die orale Gabe macht die Durchführung der Therapie ambulant möglich. Kombinationen mit wirksamen zytostatischen Substanzen scheinen die Wirksamkeit bei Gleichbleiben der Nebenwirkungen noch zu verstärken. Besonders interessant scheint die Therapie bei multiresistenten Tumoren, wie sie beim Tumorrezidiv meist vorliegen. / We here show that the physiological estrogen metabolite 2-Methoxyestradiol (2-ME) has a very strong growth inhibitory effect on cell lines from different solid cancer types. The tumors investigated were hepatocellular carcinome (HCC), pancreatic cancer, and lung cancer. All three tumor types present with a very poor prognosis, which did not improve significantly the last 20 years in spite of new operation techniques, new anticancer drugs, or new molecular approaches. Using several different cell lines of each cancer type we studied, we could confirm a generalized phenomenon of cancer growth inhibition by 2-ME. We found up to 90% growth inhibition in all cell lines with the exception of one pancreatic cancer cell line. This effect could even be increased using combination therapies of 2-ME and Gemcitabine, 5-FU, Taxol or a monoclonal antibody against the EGF receptor. We found an additive growth inhibition when all of these anticancer agents were combined with 2-ME. Our studies on lung cancer were based on previous results, where 2-ME stabilized the p53 protein. We combined 2-ME with gene therapy and used a wild-type p53 expressing adenovirus, which was administered intraveneously. 2-ME was given orally. The p53 gene was expressed in lung colonies. 2-ME stabilized the p53 protein in a quantity that there was enough p53 protein to be able to kill the cancer cells and to inhibit the cancer growth. This was the first report showing that an adenoviral gene transfer using a tumor suppressor gene can have an effect after intraveneous application. We also showed that 2-ME was able to inhibit the growth of multi-resistant pancreatic cancer cells, which were resistant to up to 1000 fold against different anticancer agents. The degree of growth inhibition after 2-ME treatment was identical between normal cancer cells and multi-resistant cancer cells. The IC50 was 0.56µM in mdr-1 gene expressing cells and 1.65µM in mdr-1 gene negative cells. These values are very similar to those seen in normal cancer cells. Lung cancer cells resistant against cisplatin also showed to be sensitive to 2-ME. Toxicitiy studies showed that cultured normal hepatocytes harvested from resected livers survived the treatment with 2-ME. Parallel studies with cancer cells showed strong growth inhibition at the same doses. Since normal hepatocytes do not proliferate in culture, we studied proliferating hepatocytes in vivo after liver resection in mice. After resection, the livers recieve a strong proliferation stimulus, which causes hepatocyte proliferation. During the regeneration, we treated the mice with 2-ME. We found no induction of apoptosis after 2-ME treatment in proliferating hepatocytes. Liver regeneration was not inhibited by 2-ME as shown by immunohistochemistry using PCNA. The major mechanism of growth inhibition due to 2-ME treatment was the induction of apoptosis in all cell lines except one pancreatic cancer cell line (PaTu 8988s). We confirmed the induction of apoptosis with several different methods. To study further mechanisms of induction of apoptosis, we performed western blot analysis for apoptosis related proteins. We found a p53 over-expression in all HCC cells expressing wild-type p53. The pancreatic cancer cells were all mutant for the p53 gene, which suggests the presence of p53 independent mechanisms of apoptosis. The tumor suppressor protein p21, a direct effector protein of p53, was also up-regulated when p53 was up-regulated, which shows that the up-regulated p53 protein is active. In one HCC cell line (SK-Hep1), which is the most sensitive to 2-ME, we found a down-regulation of the strongest anti-apoptosis protein, bcl-2. This effect causes an induction of apoptosis. Thus, different mechanisms lead to an increased induction of apoptosis. Animal experiments on nude mice show significant growth inhibition of different tumors. HCC tumors were implanted subcutaneously and were inhibited by 55%, lung metastases from lung and pancreatic cancer cells were inhibited by 55% and 59%, respectively. The combination of 2-ME and the p53 expressing adenovirus could further inhibit tumor growth by 14%. The total tumor burden could be reduced by 336 fold in this combination therapy compared to the non treated control group. The described antiangiogenetic effect in the literature could not be confirmed in our experiments on pancreatic and lung cancer. The animals did not show any sign of side effects after treatment with 2-ME such as diarrhea, weight loss, hypocinesia, or others. The animals of the control groups with lung metastases from lung or pancreatic cancer showed cachexy due to tumor burden with an average weight loss of 20% compared to the treated animals. In conclusion, 2-ME is a compound of high clinical interest. The strong efficacy in vitro and in vivo on growth inhibition of tumors with no or slight side effects led to the initiation of clinical phase I and II trials. The oral administration allows an outpatient treatment. The combination with other clinically used anti-cancer drugs appears to increase the effect on tumor growth while the side effects don''t increase. Of particular interest will be the treatment of multi-resistant cancers, for example in the case of recurrent cancer.

Ce projet vise à développer et à analyser de nouveaux nanovecteurs pour des applications biomédicales. Nous travaillons en étroite collaboration avec des chimistes pour mettre au point des nanoparticules hautement efficaces (principalement des nanoparticules de silicium poreux - pSiNPs). Mon travail consiste à évaluer la toxicité des nano-objets développés et à établir leur potentiel en terme de thérapie photodynamique et d'imagerie. Les nanovecteurs sont recouverts de sucres reconnus par les lectines surexprimées par les cellules cancéreuses. Cette interaction permet le ciblage spécifique des cellules cancéreuses par les nanovecteurs. Lors des études in vitro, nous sélectionnerons les nano-objets les plus prometteurs pour réaliser des études préliminaires in vivo. / The focus of this project concerns the development and the analysis of new nanocarriers for biomedical applications. We work in collaboration with chemists to design efficient nanoparticles (mainly porous silicon nanoparticles - pSiNPs). Then, I evaluate their cytotoxic activity and their photodynamic therapeutic effect as well as their imaging potential. Nanovectors are coated with sugar recognized by lectins overexpressed on the surface of cancer cells. This interaction permits the specific targeting of cancer cells by nanovectors synthesized. During the study in vitro, we will select the most promising nanotools for preliminary studies in vivo.