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

Analysis of genomewide expression profiles of thyroid tumors and of their in vitro models

Weiss Solís, David Y 23 March 2009 (has links)
New technologies to probe the global output of the normal and cancer genomes have recently reached widespread use. The resulting genomewide gene expression profiles, e.g, a gene expression measurement per gene and per tissue sample, remain challenging to analyze and interpret, but have already provided new insights into the pathophysiology of cancer and towards personalized care. In vitro cell culture-based experimental models are used to elucidate cancer onset and progression because experimentation in humans is difficult practically and ethically unacceptable, and because they provide simplified, reproducible and controlled systems to test hypotheses. The thyroid tumors and their in vitro experimental models are particularly suited to compare the molecular phenotypes of experimental models and tumors. From one type of cell, the thyrocyte, at least five distinct benign and malignant tumors can arise. In addition, many immortalized tumor-derived cell lines and primary cultures models of these cells exist. This thesis has focused on the bioinformatic comparison of these in vitro models to the in vivo tumors, from the point of view of their gene expression profiles, to gain insight into the pathogenesis of thyroid tumors, and of tumors in general. In a first study, we showed that primary cultures of freshly isolated normal thyroid cells where proliferation and differentiation through the TSHR/cAMP pathway was chronically activated experimentally resemble specifically the autonomous thyroid adenomas, a type of benign thyroid tumor, and provide insight into a general mechanism of tumor progression: the suppression of negative feedbacks that normally restrain excessive cell division. Subsequently, we found that immortalized thyroid tumor-derived cell lines have converged to a common phenotype regardless of their tumor subtype of origin. A TSHR/cAMP thyroid cell differentiation signature, derived from data obtained for the first study, was used to show that the cell lines were dedifferentiated. Accordingly, we showed that the cell lines resemble most the phenotype of the more dedifferentiated, clinically aggressive anaplastic thyroid cancers. Finally, using large databases of gene expression profiles publicly available, we extended the comparison of cell lines and tumors to cancers of five other organs: breast, colon, kidney, ovary and lung. We discuss the correct use of these models and advance an hypothesis regarding the nature of the state to which these cells have converged: they could represent a surviving subpopulation of tumors cells, cancer stem cells, capable of initiating and maintaining tumor growth. As other technologies designed to perturb the genome in experimental models are emerging, careful characterization and validation of the experimental models are needed to extrapolate the results in vivo. Although many differences exist between the experimental models and their in vivo disease counterparts, focusing on the similarities could provide a path to design successful therapeutic interventions more systematically.
2

Analysis of genomewide expression profiles of thyroid tumors and of their in vitro models

Weiss Solís, David Y 18 May 2009 (has links)
New technologies to probe the global output of the normal and cancer genomes have recently reached widespread use. The resulting genomewide gene expression profiles, e.g, a gene expression measurement per gene and per tissue sample, remain challenging to analyze and interpret, but have already provided new insights into the pathophysiology of cancer and towards personalized care. In vitro cell culture-based experimental models are used to elucidate cancer onset and progression because experimentation in humans is difficult practically and ethically unacceptable, and because they provide simplified, reproducible and controlled systems to test hypotheses. The thyroid tumors and their in vitro experimental models are particularly suited to compare the molecular phenotypes of experimental models and tumors. From one type of cell, the thyrocyte, at least five distinct benign and malignant tumors can arise. In addition, many immortalized tumor-derived cell lines and primary cultures models of these cells exist. This thesis has focused on the bioinformatic comparison of these in vitro models to the in vivo tumors, from the point of view of their gene expression profiles, to gain insight into the pathogenesis of thyroid tumors, and of tumors in general. In a first study, we showed that primary cultures of freshly isolated normal thyroid cells where proliferation and differentiation through the TSHR/cAMP pathway was chronically activated experimentally resemble specifically the autonomous thyroid adenomas, a type of benign thyroid tumor, and provide insight into a general mechanism of tumor progression: the suppression of negative feedbacks that normally restrain excessive cell division. Subsequently, we found that immortalized thyroid tumor-derived cell lines have converged to a common phenotype regardless of their tumor subtype of origin. A TSHR/cAMP thyroid cell differentiation signature, derived from data obtained for the first study, was used to show that the cell lines were dedifferentiated. Accordingly, we showed that the cell lines resemble most the phenotype of the more dedifferentiated, clinically aggressive anaplastic thyroid cancers. Finally, using large databases of gene expression profiles publicly available, we extended the comparison of cell lines and tumors to cancers of five other organs: breast, colon, kidney, ovary and lung. We discuss the correct use of these models and advance an hypothesis regarding the nature of the state to which these cells have converged: they could represent a surviving subpopulation of tumors cells, cancer stem cells, capable of initiating and maintaining tumor growth. As other technologies designed to perturb the genome in experimental models are emerging, careful characterization and validation of the experimental models are needed to extrapolate the results in vivo.
3

Microcarcinomas de tireóide = avaliação da utilidade das classificações de prognóstico na evolução clínica da conduta no seguimento / Thyroid microcarcinomas : evaluation of the usefulness of prognostic classidicationsystems on clinical outocome and of management on follow-up

Facuri, Flávia de Oliveira 17 August 2018 (has links)
Orientadores: Ligia Vera Montali da Assumpção, Laura Sterian Ward / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-17T14:23:42Z (GMT). No. of bitstreams: 1 Facuri_FlaviadeOliveira_M.pdf: 578836 bytes, checksum: 4c224d3c01a3c8a3e00291b69608eec2 (MD5) Previous issue date: 2007 / Resumo: Com o aprimoramento dos métodos diagnósticos, houve um aumento na incidência dos microcarcinomas (MC) de tiróide, definidos como tumores com tamanho menor ou igual a 1 cm, principalmente os diferenciados, considerados de excelente prognóstico. No entanto, há relatos de casos de MC em que ocorrem recorrências e até metástases à distância. Ainda não há um consenso quanto aos critérios mais precisos para distinguir quem são esses pacientes. Os objetivos desse trabalho foram: verificar os aspectos clínicos, laboratoriais e de evolução em uma população portadora de microcarcinoma diferenciado da tireóide e compará-los às possíveis diferenças dos pacientes com carcinoma diferenciado de tireóide (CDT) maiores que 1cm, ou seja, os não-microcarcinomas (NMC). Também procuramos correlacionar o estadiamento ao diagnóstico, de acordo com dois critérios diferentes (TNM e Ohio State University - OSU), com a evolução clínica dos pacientes com CDT, enfatizando os portadores de MC. Para isso, foram selecionados 308 dos 365 prontuários retrospectivamente estudados de pacientes atendidos de 1982 a 2005 no ambulatório de Câncer de Tireóide do Hospital de Clínicas da Universidade Estadual de Campinas, seguidos de acordo com o mesmo protocolo de conduta. A média de seguimento foi de 88,3 ± 66,8 meses (mediana de 67,5 meses), sendo 226 com carcinoma papilífero (CP) e 82 com carcinoma folicular (CF), 254 (82,5%) do sexo feminino e 54 (17,5%) do sexo masculino. Analisaram-se 3 grupos: microcarcinomas (Grupo 1, n = 38) e carcinomas maiores de 1 cm (NMC): 170 CP (Grupo 2) e 57 CF (Grupo 3), de acordo com estadiamento pelos critérios do TNM e da OSU e evolução clínica favorável - considerada como ausência imagem suspeita ao ultrassom e de captação de 131I na PCI e tireoglobulina sérica indetectável - ou desfavorável - considerada como presença de metástase detectável em região cervical ou à distância por qualquer método de imagem ou por tireoglobulina sérica detectável. . Nossa análise estatística demonstrou que os pacientes com NMC estadio I e II tanto pelo TNM quanto pelo critério OSU evoluem mais favoravelmente que os estadios III e IV (p=0,0001). Além disso, os pacientes com estadio III e IV pelo critério OSU apresentam risco maior para evolução desfavorável (89%; OR = 15,5) do que os com estádio III e IV pelo TNM (42% - OR = 9,2). Dessa forma, os pacientes classificados como estadio OSU III e IV apresentam chance 10 vezes maior de evolução desfavorável do que os classificados como estadios OSU I e II, enquanto que essa chance para a classificação TNM é apenas 3,2 vezes maior. No entanto, para os MC, o estadiamento não foi útil para diferenciar a evolução clínica favorável ou desfavorável (p= 0,339). Quando comparados aos NMC, os MC apresentam melhor evolução (p= 0,015). Concluímos que os pacientes com MC apresentam boa evolução, sugerindo que seja possível tratá-los de forma menos intervencionista. Entretanto, os sistemas de estadiamento atualmente em uso não definem prognóstico nestes pacientes. Será necessário um seguimento mais longo, em particular para os pacientes com MC que apresentem uma evolução desfavorável, bem como a identificação de outros fatores e/ou marcadores de mau prognóstico para caracterizar a sua evolução / Abstract: The improvement of diagnostic methods has led to an increase in the frequency of microcarcinomas (MC), defined as tumors ? 1 cm, mainly differentiated histologic types, often with an excellent prognosis. However, there are reports of MC that present recurrence and even distant metastasis. Still, there is not an agreement on the best criteria to identify these patients. The present study aims to verify the clinical, laboratorial aspects and clinical evolution in patients with differentiated thyroid microcarcinoma and compare them to patients with differentiated thyroid carcinoma (DTC) > 1cm (NMC). We also tried to correlate the initial stage, according to TNM and OSU staging systems, with clinical evolution of patients with DTC, emphasizing MC. We retrospectively studied 308 of 365 records of patients followed at the outpatient ambulatory of Thyroid Cancer at State University of Campinas from 1982 to 2005, followed by the same protocol. The median follow-up was 88,3 ± 66,8 months (median 67,5 months), 226 papillary (PC) and 82 follicular (FC) carcinomas, 254 (82,5%) females and 54 (17,5%) males. We analyzed 3 groups: microcarcinomas (Group 1, n = 38) and carcinomas > 1cm (NMC): 170 PC (Group 2) and 57 FC (group 3) for stage and clinical evolution. The statistic analysis showed that patients with NMC both TNM and OSU stage I and II have a better prognosis than stages III and IV (p=0,0001). Furthermore, patients stage OSU III and IV are at higher risk of a poor prognosis (89%; OR = 15,5) than TNM III and IV (42% - OR = 9,2). Therefore, patients stage OSU III and IV have a ten-fold risk of a bad outcome than I and II, while TNM III and IV have only a 3,2-fold risk of a bad outcome. However, the staging systems did not help in predicting good or poor prognosis of MC (p= 0,339), as they usually have good prognosis (p= 0,015). Thus, we conclude that, like other studies recently published, MC could be treated less aggressively, due to its good prognosis. Nevertheless, the staging systems currently in use do not contribute to predict prognosis in these patients. It will be necessary to wait for a longer follow-up of the patients with MC who present a poor outcome and to identify the various risk factors and/or markers to predict the risk of a bad prognosis / Mestrado / Clinica Medica / Mestre em Clinica Medica
4

Avaliação da utilidade clinica dos genes ATM e PTEN em cancer bem diferenciado da tireoide / Investigation of clinical utility of ATM and PTEN genes in the differentiated thyroid cancer

Guilhen, Ana Carolina Trindade 14 August 2018 (has links)
Orientador: Laura Sterian Ward / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-14T20:56:12Z (GMT). No. of bitstreams: 1 Guilhen_AnaCarolinaTrindade_D.pdf: 3271210 bytes, checksum: d47667ab13437068977eea82cbadb8a1 (MD5) Previous issue date: 2009 / Resumo: Para investigar a utilidade clínica de dois genes supressores tumorais envolvidos no controle da proliferação e sobrevivência celular, nós estudamos por imunoistoquímica as proteínas ATM e PTEN em 272 pacientes diagnosticados carcinoma diferenciado da tireóide (142 carcinomas papilíferos do tipo clássico, 72 carcinomas papilíferos variante folicular, 17 carcinomas papilíferos de células altas e 41 carcinomas foliculares); 106 amostras de tecido de pacientes diagnosticados com doenças tiroidianas benignas (55 adenomas foliculares e 51 com bócio), 18 tecidos de tiróide normal extraídos de lobo contra-lateral de indivíduos operados por adenoma folicular. A expressão quantitativa de ATM foi avaliada por Real-Time PCR em 87 CP. Ainda, analisamos o perfil genotípico para três polimorfismos de ATM (D1853N, S707P e S49C) em 199 pacientes (164 carcinomas papilíferos e 35 carcinomas foliculares) e 219 indivíduos controles. Os pacientes foram seguidos por 53,8±41 meses utilizando-se um protocolo padrão. 179 pacientes foram classificados como livre de doença e 48 pacientes tiveram má evolução (recidivas e 12 mortes). A análise da regressão logística múltipla ajustada para sexo e faixa etária mostrou que a expressão da proteína ATM foi mais freqüente entre os pacientes que apresentavam tumores menos agressivos (81%) e que evoluíam livres de doença (63%) (p=0.016; p=0.0276 respectivamente). Maior incidência de casos que expressavam a proteína PTEN também foi observada em pacientes que não tiveram metástase na evolução (75%) (p= 0.0437). O alelo heterozigoto para o polimorfismo D1853N de ATM foi mais prevalente entre os controles (64%) do que nos indivíduos com câncer (36%) (p=0.0364) Estes dados indicam que ATM e PTEN podem ser úteis na identificação de agressividade e na classificação de prognóstico do CDT. / Abstract: In order to investigate the clinical utility of two tumor-suppressing genes involved in the control of cell proliferation and survival, we've studied proteins ATM and PTEN through immunohistochemistry in 272 differentiated thyroid carcinoma diagnosed patients (142 classical papillary thyroid carcinomas type, 72 papillary thyroid carcinomas follicular variant, 17 papillary thyroid carcinomas tall cells variant and 41 follicular carcinomas), 106 tissue samples from patients diagnosed with benign thyroid diseases (55 follicular thyroid adenomas and 51 with goiter), 18 normal thyroid tissue samples extracted from the counter lateral lobe of individuals operated for follicular thyroid adenomas. The quantitative expression of ATM gene was available for Real-Time PCR in 87 papillary carcinomas. In order to analyze the genotypic profile, we've also studied three ATM polymorphisms (D1853N, S707P e S49C) in 199 patients (164 papillary carcinomas and 35 follicular carcinomas) and 219 control individuals. Patients were accompanied for 53,8±41 months, using a standard protocol. 179 patients were tagged as disease-free and 48 patients had bad outcome (12 deaths). The analysis of multiple logistic regression adjusted for gender and age has showed that the ATM protein expression was more frequent among patients that didn't have metastasis when diagnosed (81%) and that were free of disease (63%) (p=0.016; p=0.0276 respectively). The major incidence of cases who expression PTEN protein, also was observed in patients that didn't have metastasis during follow- up (75%) (p= 0.0437). The heterozygous alleles for D1853N polymorphism was more prevailing among the controls (64%) than in individuals with cancer (36%) (p=0.0364). Nevertheless these results demonstrated that ATM and PTEN protein expression can be useful in identifying patients with aggressiveness and the classification of prognosis in differentiated thyroid carcinoma. / Doutorado / Clinica Medica / Doutor em Clínica Médica
5

Metabolismus inhibitoru tyrosinkinas lenvatinibu jako protinádorového léčiva s cílenými účinky / Metabolism of an inhibitor of tyrosine kinase lenvatinib as the anticancer drug with targeting effects

Vavrová, Katarína January 2018 (has links)
Lenvatinib is an oral anticancer drug that belongs to a group of tyrosine kinases, which block signal pathway receptors for development and proliferation of various cancer diseases. Lenvatinib was approved in 2015 for a treatment of progressive, locally spread or metastatic, differentiated thyroid cancer refractory to radioiodine treatment. This thesis presents findings about the metabolism of lenvatinib and identification of enzymes responsible for biotransformation of this drug. Utilizing human and rat hepatic microsomes as well as recombinant cytochromes P450 (CYPs) expressed in SupersomesTM , the metabolism of lenvatinib was studied. Used rat microsomal systems were isolated from the liver of uninduced rats and from the liver of rats in which expression of individual CYPs was induced by CYP inducers. The lenvatinib metabolites were separated by HPLC and identified by mass spectroscopy. Using rat microsomal systems, O-desmethyllenvatinib and lenvatinib N-oxide were produced. The highest amount of these lenvatinib metabolites was produced by microsomes of rats pretreated with pregnenolone carbonitrile that is an inducer of CYP3A. Human hepatic microsomes oxidize lenvatinib to O-desmethyllenvatinib and N-descyklopropyllenvatinib. In the case of rat recombinant CYPs, O-desmethyllenvatinib was...
6

Analysis of genomewide expression profiles of thyroid tumors and of their in vitro models

Weiss, David 18 May 2009 (has links)
New technologies to probe the global output of the normal and cancer genomes have recently reached widespread use. The resulting genomewide gene expression profiles, e.g, a gene expression measurement per gene and per tissue sample, remain challenging to analyze and interpret, but have already provided new insights into the pathophysiology of cancer and towards personalized care.<p><p><p>In vitro cell culture-based experimental models are used to elucidate cancer onset and progression because experimentation in humans is difficult practically and ethically unacceptable, and because they provide simplified, reproducible and controlled systems to test hypotheses. The thyroid tumors and their in vitro experimental models are particularly suited to compare the molecular phenotypes of experimental models and tumors. From one type of cell, the thyrocyte, at least five distinct benign and malignant tumors can arise. In addition, many immortalized tumor-derived cell lines and primary cultures models of these cells exist.<p><p><p>This thesis has focused on the bioinformatic comparison of these in vitro models to the in vivo tumors, from the point of view of their gene expression profiles, to gain insight into the pathogenesis of thyroid tumors, and of tumors in general.<p><p><p>In a first study, we showed that primary cultures of freshly isolated normal thyroid cells where proliferation and differentiation through the TSHR/cAMP pathway was chronically activated experimentally resemble specifically the autonomous thyroid adenomas, a type of benign thyroid tumor, and provide insight into a general mechanism of tumor progression: the suppression of negative feedbacks that normally restrain excessive cell division.<p><p><p>Subsequently, we found that immortalized thyroid tumor-derived cell lines have converged to a common phenotype regardless of their tumor subtype of origin. A TSHR/cAMP thyroid cell differentiation signature, derived from data obtained for the first study, was used to show that the cell lines were dedifferentiated. Accordingly, we showed that the cell lines resemble most the phenotype of the more dedifferentiated, clinically aggressive anaplastic thyroid cancers.<p><p><p>Finally, using large databases of gene expression profiles publicly available, we extended the comparison of cell lines and tumors to cancers of five other organs: breast, colon, kidney, ovary and lung. We discuss the correct use of these models and advance an hypothesis regarding the nature of the state to which these cells have converged: they could represent a surviving subpopulation of tumors cells, cancer stem cells, capable of initiating and maintaining tumor growth.<p><p><p>As other technologies designed to perturb the genome in experimental models are emerging, careful characterization and validation of the experimental models are needed to extrapolate the results in vivo.<p> / Doctorat en sciences biomédicales / info:eu-repo/semantics/nonPublished

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