Made available in DSpace on 2014-10-09T12:35:31Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:04:02Z (GMT). No. of bitstreams: 0 / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Cyst enlargement is an important part of the initial stage of organ formation. in vitro experiments have shown that the speed of expansion of this nearly spherical object is affected by many factors. Moreover, in many cases, bursting of the cyst cell layer takes place from time to time, leading to nearly periodic deflation of the cyst sphere. Biophysical models have been proposed that take into account the build-up of osmotic pressure in the lumen and cell proliferation in the cyst layer. Here we integrate two previous models for Hydra cyst swelling and collapse cycle and MDCK cyst growth saturation respectively to describe the Caco-2 cyst swelling and rupture cycle in a series of experiments carried out in Prof. Jian-Dong Huang’s lab at HKU. Gene expression analysis is also carried out to identify pathways that are over-expressed and active during cyst enlargement.

Orientador: Marcio Ajudarte Lopes / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-10T15:16:37Z (GMT). No. of bitstreams: 1 Gouvea_AdrieleFerreira_M.pdf: 32361877 bytes, checksum: 44730f369ba904c501c24d39c84b43fc (MD5) Previous issue date: 2008 / Resumo: Leucoplasia verrucosa proliferativa é uma forma agressiva de leucoplasia oral, que afeta mais mulheres acima de 60 anos, sem história de etilismo e tabagismo. Tem apresentação clínica multifocal, mostra recorrência e sempre desenvolve displasia epitelial e carcinoma espinocelular (CEC). O objetivo deste trabalho foi avaliar os achados clínico-patológicos e a expressão imunohistoquímica de ki-67, p53, Mcm2 e Mcm5, na tentativa de elucidar o comportamento biológico distinto desta condição. Os dados clínico-patológicos de 12 pacientes foram revisados. Todos eram mulheres, acima de 50 anos (50% acima de 70 anos), 91,7% eram não fumantes e nenhuma etilista habitual. Os casos acompanhados por mais tempo mostraram aspectos clínicos compatíveis com lesões iniciais com presença de hiperqueratose e acantose, desenvolvimento de diferentes graus de displasia e CEC. Os locais mais acometidos foram rebordo alveolar (66,6%), língua (50%) e mucosa jugal (41,6%). Quatro pacientes desenvolveram CEC. Os achados imunohistoquímicos mostraram expressões variáveis em cada marcador. As áreas epiteliais sem displasia mostraram imunopositividade fraca para p53 e ki- 67 e moderada para Mcm2 e Mcm5; os casos de displasia leve tiveram expressão fraca de p53, moderada de ki-67 e Mcm5 e forte de Mcm2; displasia moderada exibiu marcação fraca de Mcm5 e de p53 e Mcm2, além de expressão moderada de ki-67; CEC mostrou expressão fraca de Mcm5, moderada de Mcm2 e forte de ki-67 e p53. Não foi observado, na maioria dos casos, um padrão regular de aumento de marcação imunohistoquímica conforme avanço do grau de displasia epitelial. A expressão de ki-67, Mcm2 e Mcm5 mostrou-se variada, com casos de displasias leves apresentando forte imunopositividade / Abstract: Proliferative verrucous leukoplakia (PVL) is an aggressive form of oral leukoplakia that affects particularly women over 60 years of age, without tobacco and alcohol intake history. Has multifocal presentation, presents recurrences and always develops epithelial dysplasia and squamous cell carcinoma (SCC). The aim of this study was to evaluate the clinico-pathological findings and the ki-67, p53, Mcm2 and Mcm5 immunohistochemical expression, in order to elucidate the distinct biologic behavior of this condition. The clinico-pathological data of 12 patients were reviewed. All were women, above 50 years (50% above 70 years of age), 91.7% were non smoker and 100% were non-drinker. The cases with longer follow-up showed clinical aspects compatible with initial lesions presenting hyperkeratosis and acantosis, development of different grade of epithelial dysplasia and SCC. Alveolar ridge (66,6%), tongue (50%) and buccal mucosa (41,6%) were the most affected sites. Four patients developed SCC. The immunohistochemical findings showed variable expression for each antibody. Areas without epithelial dysplasia showed weak positivity to p53 and ki-67 and moderate to Mcm2 and Mcm5. Mild dysplasia cases showed weak positivity to p53, moderate to ki-67and Mcm5 and strong to Mcm2; moderate dysplasia exhibited weak p53, Mcm2 and Mcm5 expression and moderated ki-67 imunopositivity; SCC showed weak Mcm5 positivity, moderate expression of Mcm2 and strong imunopositivity of ki-67 and p53.The majority of the cases did not show a regular pattern of increasing immunohistochemical expression according to higher grades of epithelial dysplasia. Ki-67, Mcm2 and Mcm5 showed variable imunopositivity, with some mild dysplasia cases presenting strong expression / Mestrado / Patologia / Mestre em Estomatopatologia

Meduloblastoma é o câncer do Sistema Nervoso Central mais comum em crianças entre 0 e 4 anos. Ele é originado de células precursoras neuronais, que falharam em se diferenciar e continuaram a se proliferar. A proteína SAM68 está desregulada em várias linhagens de células de cânceres humanos e é uma proteína que pode estar envolvida em uma ampla gama de vias de sinalização importantes, incluindo metabolismo de RNA, regulação do ciclo celular, apoptose, regulação de splicing e transdução de sinal. Em células-tronco neurais (NSC), níveis elevados de SAM68 levam a uma redução importante na proliferação celular. Contudo, na maioria dos cânceres estudados até o momento, a SAM68 está envolvida com progressão tumoral. Com este trabalho, buscou-se entender o envolvimento de SAM68 na proliferação e morte de células de meduloblastoma. Por meio da análise de expressão transcricional e proteica, do silenciamento de SAM68, análise de apoptose por citometria de fluxo e análise de proliferação por índice mitótico e incorporação de EdU, observou-se que, em linhagens de meduloblastoma, a SAM68 está envolvida com proliferação, mas não com apoptose. Seu funcionamento em meduloblastoma é similar aos resultados obtidos com NCS do que com outros tipos de câncer, visto que o silenciamento dessa proteína favorece a proliferação das células de meduloblastoma. Em vista dos resultados aparentemente conflitantes, tendo um papel mais semelhante a um supressor tumoral, porém sendo altamente expressa em meduloblasoma, sugeriram-se algumas hipóteses, que foram apenas inicialmente testadas neste trabalho, mas precisam ser aprofundadas em trabalhos futuros / SAM68 is considered a prototype of STAR proteins (Signal Transducers and Activators of RNA protein), that are involved in the signal translation and RNA activation. In cancer, the intracellular levels of Sam68 are crucial to the progression of the disease. Recent observations indicate Sam68 with both pro-oncogenic and tumor suppressor activities, depending on the type of cell. Here, we analyzed SAM68 expression by real time PCR and western blot, proliferation of cell with and without SAM68 by mitotic index and incorporation of EdU and cell death by flux cytometry to define the relevance of the presence of SAM68 to cell proliferation and death. We found that proliferation of medulloblastoma cell lines are affected for absent SAM68, but not apoptosis. Because the contrast of an action similar to a tumor suppressor and a high expression level, we hypothesized that the increase of SAM68 levels is important during the neuronal development, regulating splicing variants. Our results allied to some literature data corroborate this hypothesis

Made available in DSpace on 2014-10-09T12:35:31Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:04:02Z (GMT). No. of bitstreams: 0 / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Orientador: Pablo Augustin Vargas / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-15T10:55:45Z (GMT). No. of bitstreams: 1 Rocha_LiliaAlves_D.pdf: 2316332 bytes, checksum: 8ea247f73bbb3c563d66cdcf3dcabe9e (MD5) Previous issue date: 2010 / Resumo: O presente trabalho avaliou a expressão dos marcadores de proliferação celular Ki-67, Mcm-2 e HOXB7 em neoplasias malignas epiteliais basalóides de cabeça e pescoço. Foram avaliadas 42 amostras tumorais da região de cabeça e pescoço, sendo 15 de carcinoma espinocelular pouco diferenciado (CEC-pd), 18 de carcinoma escamoso basalóide (CEB) e nove de carcinoma adenóide cístico tipo sólido (CAC-sólido). Os dados clinicopatológicos foram coletados de formulários de encaminhamento para biópsia. Todas as amostras foram submetidas à análise imunoistoquímica para os três marcadores. A idade média dos pacientes avaliados foi de 57 (±14,5) anos, e a maioria pertenceu ao gênero masculino (76%). A expressão de Ki-67 nas amostras de CAC-sólido foi menor quando comparada com os demais grupos tumorais (IM=18,74% ±8,3, p<0,05). A proteína Mcm-2 apresentou um maior IM no grupo CEB (IM=55,57% ±13,4, p<0,05), quando comparado com os grupos CEC-pd (IM=35,55% ±19,5) e CAC-sólido (IM=28,60%, ±10,1). Este mesmo padrão foi observado para a proteína HOXB7, que apresentou um maior IM no grupo de CEB (IM=31,28% ±11,6, p<0,05), quando comparado aos demais grupos (CEC-pd: IM=23,19% ±8,4 e CAC-sólido: IM=18,66% ±9,8). Como o CEB apresenta um comportamento clínico mais agressivo quando comparado ao CEC-pd e CAC-sólido, os altos IMs para Mcm-2 e HOXB7 em CEB sugerem uma relação direta entre a maior expressão dessas proteínas e a agressividade tumoral. Os IMs de Mcm-2 e HOXB7 foram crescentes para os grupos CAC-sólido, CEC-pd e CEB. Assim, sugerimos que as proteínas Mcm-2 e HOXB7 podem ser úteis no diagnóstico diferencial de CEB, CEC-pd e CAC-sólido. Estudos adicionais devem ser realizados para confirmar nossos achados e determinar o valor prognóstico de Mcm-2 e HOXB7 nestas neoplasias malignas de cabeça e pescoço. / Abstract: The aims of this study were to determine the expression of Mcm-2, Ki-67 and HOXB7 in malignant basaloid tumors located in the head and neck region, and to evaluate their usefulness for diagnosis or prediction of tumor behaviour. There were 18 basaloid squamous cell carcinoma (BSCC), 15 squamous cell carcinoma poorly differentiated (SCC-pd), and nine adenoid cystic carcinoma solid type (AdCC-st). Clinicopathological data were collected retrospectively and immunohistochemical analyses of Ki-67, Mcm-2 and HOXB7 were performed on all lesions (n=42). The nuclear stain was considered as positive or negative, and labelling index (LI) for each tumor was determined by counting the percentage of positive cells in six random fields. The mean age of patients was 57 years (±14,5), and the most was male (76%). Ki-67 expression was lower in AdCC-st (LI=18,74% ±8,3, p<0,05) than in BSCC (LI=42,22%) and SCC-pd (LI=43,54) groups. Mcm-2 LI was higher in BSCC (LI=55,57% ±13,4, p<0,05) than in SCC-pd (LI=35,55 ±19,5) and AdCC-st (LI=28,60% ±10,1). A similar result was observed in HOXB7 that showed a higher LI expression in BSCC group (LI=31,28% ±11,6, p<0,05) than in SCC-pd (IM=23,19% ±8,4) and AdCC-st (LI=18,66% ±9,8). It was not possible to establish a correlation between LI and outcome for any of the markers. The present study suggests that Mcm-2 and HOXB7 may be useful for differential diagnosis among BSCC, SCC-pd and AdCC-st. Further studies are needed to assess the value of Mcm-2 and HOXB7 as a predictor of recurrence and survival in malignant basaloid tumors of head and neck region. / Doutorado / Patologia / Doutor em Estomatopatologia

Luminal epithelial cells in the mammary gland require two types of signals to proliferate: soluble signals (growth factor signals) and signals from the extracellular matrix (ECM). The composition of the ECM is sensed by adhesion receptors such as integrins. Integrins modulate cell behaviour and play a key role in cell cycle entry. Altered integrin expression and signalling has been associated with breast cancer and studies using mouse mammary epithelial cells (MECs) have shown that the absence of β1-integrin induces growth arrest. However, it is not completely understood how integrins transduce the signals from the plasma membrane to the nucleus to induce cell cycle entry. Thus, the first aim of this project was to determine how β1-integrin controls proliferation in MECs. I established a model to study the effects of depleting β1-integrin using the FSK7 mammary epithelial cell line. The proliferation defect observed in this β1-integrin knockdown model was rescued by expressing a constitutively active Rac1 or Pak. Moreover, inhibiting Rac1 or Pak prevented normal proliferation in MECs in a similar fashion as β1-integrin depletion. Furthermore, in this thesis I have identified the complex comprised of Src, paxillin and p130Cas as a potential link between β1-integrin and Rac1. These results provide an insight into the mechanism that regulates proliferation downstream of β1-integrin. During breast cancer initiation, β1-integrin signals are disrupted. This indicates that additional signals must be driving proliferation during tumorigenesis. Therefore, the second aim of this project was to test whether expression of breast oncogenes can overcome the proliferation defect present in β1-integrin null cells. In order to do so, an oncogenic ErbB2, a constitutively active form of Akt (myrAkt) and the Notch1 intracellular domain (NICD) were transfected in the β1-integrin knockdown MECs. The results showed that ErbB2 overcomes the need for β1-integrin by signalling to Pak. NICD does not require β1-integrin to drive proliferation by an unknown mechanism. Expression of myrAkt did not restore normal levels of proliferation in β1-integrin depleted MECs. This finding suggests that Akt is not sufficient to induce cell cycle entry by itself and instead, both Akt and Erk signalling are needed to exert this function. This work has further delineated the specific signals controlling proliferation downstream of β1-integrin, and has provided a model to test the dependence of oncogenes for β1-integrin to drive proliferation in MECs. These studies are important to understand the role of β1-integrin in breast cancer formation and to define the types of breast cancer where β1-integrin can be used as an effective therapeutic target.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第18513号 / 医博第3933号 / 新制||医||1006(附属図書館) / 31399 / 京都大学大学院医学研究科医学専攻 / (主査)教授 松田 道行, 教授 羽賀 博典, 教授 小川 誠司 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Zahlreiche epidemiologische Studien zeigen für das Antidiabetikum Metformin anti-Tumor-Effekte, die bisher ansatzweise für verschiedene Tumorzelllinien in vitro bestätigt wurden. Ziel der vorliegenden Arbeit war, den antiproliferativen Effekt von Metformin an sechs humanen kolorektalen Karzinomzelllinien (Co-lo678, Colo741, HT29, HCT116, LS174T, RKO) zu untersuchen. Zur Identifizierung eines anti-proliferativen Effektes von Metformin bei kolorektalen Karzinomzellen wurde ein Konzentrationsbereich von 1 bis 100 mmol/L untersucht. Die für die Tumorzelllinien bestimmte halbmaximale inhibitorische Konzentration (IC50) von Metformin reichte von 0,8 mmol/L (HT29) über 16 mmol/L (Colo678) bis >40 mmol/L (RKO). Der IC50 für die beiden nicht-transformierten Kontrollzellen lag ebenfalls über 40 mmol/L. Um die Untersuchungen in vitro bei relevanten tumorphysiologischen Bedingungen durchführen zu können, die der Situation von Tumorzellen in einem soliden Tumor wie dem kolorektalen Karzinom möglichst nahekommt, wurden die Zellen bei unterschiedlichen Sauerstoff- und Glukosekonzentrationen kultiviert. Ein permanent erhöhter Blutzuckerspiegel hat sich als grundlegender Faktor für malignes Zellwachstum erwiesen. Der anti-proliferative Effekt von Metformin in Normoxie war nahezu unbeeinflusst von den untersuchten Glukosekonzentrationen (2,5; 5,0; 11 mmol/L). Dagegen nahm in Hypoxie im Vergleich zu Normoxie der antiproliferative Effekt von Metformin bei 4 von 6 Tumorzelllinien um mehr als das Doppelte ab. Ein zentrales Target der Metformin-Wirkung stellt die AMPK, ein wichtiges Enzym für den Energiestoffwechsel der Zelle, dar. Ihre phosphorylierte Form war in den Tumorzelllinien nachzuweisen, doch der anti-proliferative Effekt von Metformin war nicht durch den AMPK-Inhibitor Compound C zu hemmen. Ein antiproliferativer Effekt von Metformin war bei kolorektalen Karzinomzellen nachzuweisen, doch bleiben die durch Metformin ausgelösten molekularen Mechanismen in der Tumorzelle weiterhin wenig verstanden. / Anti-tumor effects of the antidiabetic drug metformin were demonstrated by numerous epidemiological studies, but only verified in a few in vitro studies. The purpose of this study was to examine the antiproliferative effect of metformin in six human colorectal carcinoma cell lines (Colo678, Colo741, HT29, HCT116, LS174T, RKO). To identify an antiproliferative effect a concentration range between 1 to 100 mmol/L was evaluated. The range of the calculated half maximal inhibitory concentration (IC50) for the tumor cell lines reached from 0,8 mmol/L (HT29) over 16 mmol/L (Colo678) to >40 mmol/L (RKO). For both non-transformated control cell lines the IC50 reached also over 40 mmol/L. The cells were cultivated in different oxygen and glucose concentrations for the in vitro simulation of relevant tumorphysiological conditions. Permanently increased blood sugar levels have proven to be a significant parameter for malignant cell growth. The antiproliferative effect of metformin in normoxia remained uneffected by the tested glucose concentrations (2,5; 5,0; 11 mmol/L). In contradiction hypoxia showed a more than 50% decrease of the antiproliferative effect of metformin in 4 out of 6 tumor cell lines. The AMPK - an important enzyme for energy metabolism - acts as a central target of metfomin. The phosphorylated condition of AMPK was detected in the tumor cell lines, despite that the AMPK inhibitor compound C could not affect the antiproliferative effect of metformin. The antiproliferative effect of metformin on colorectal cell lines was verified, while the molecular mechanism in tumor cells remain insufficiently understood.

This diploma thesis deals with the issue of nuclear proliferation, specifically the motives of Iran's nuclear program. Given the unprecedented destructive potential of nuclear weapons, the international community has been trying to influence the course of Iran's nuclear policy for three decades. Unfortunately, their success has been limited. The aim of this work is to identify proliferation motives of Iran and to outline some of the steps that could be taken to minimize them. A basic theoretical framework was chosen, the conceptualization of Scott Sagan who categorizes the motives into three main groups - domestic, security and normative. However, because these models lack a clear identification of variables, the framework has been supplemented by specific indicators taken from the Stephen Meyer's concept. The work is instrumental case study, whose conclusion confirms the assumption that the realistic approach to the proliferation of nuclear weapons does not explain the overall structure of the motivation of the Islamic Republic of Iran.