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Identificação de proteínas estruturais em tumores de bexiga de bovinos
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Orientador(es)
Resumo(s)
A Hematúria Enzoótica Bovina (HEB) é uma doença de evolução arrastada associada à
ingestão do feto comum (Pteridium aquilinum), em que a principal característica é o
desenvolvimento de tumores da bexiga. Esta doença é endémica em diferentes zonas do
Globo onde se encontram condições favoráveis ao crescimento da planta, incluindo o
Arquipélago dos Açores. Os objectivos do presente trabalho foram os de (i) pesquisar através
de métodos de imuno-histoquímica a expressão das proteínas estruturais das células uroteliais,
uroplaquina III (UPIII) e citoqueratina 7 (CK7), em carcinomas do urotélio da bexiga de
animais afectados pela HEB, e a sua possível associação com o grau e estadio tumorais, (ii)
pesquisar a expressão dos factores reguladores do ciclo celular Ciclina D1 e p53, e a sua
possível associação com o grau e estadio tumorais, (iii) analisar o possível valor dos tumores
da bexiga de bovinos como modelo para os tumores de bexiga de outros animais e dos
humanos.
Os resultados demonstram que a expressão da UPIII é perdida em carcinomas do urotélio de
alto grau e invasivos, tendo esta característica sido associada estatisticamente com estes dois
parâmetros. Do mesmo modo, a perda da expressão de CK7 observada em carcinomas de alto
grau e invasivos foi associada estatisticamente com ambos os parâmetros. A sobre-expressão
da Ciclina D1 foi identificada em todos os graus e estadios tumorais, não tendo sido
observadas diferenças estatisticamente significativas. Devido a problemas de ordem técnica a
avaliação da sobre-expressão da p53 reduziu a casuística apenas a 4 casos, não sendo possível
propor associações estatisticamente válidas.
Este trabalho traz novos dados que auxiliam na compreensão das alterações moleculares
envolvidas no desenvolvimento de tumores de bexiga de bovinos com origem no epitélio de
transição, podendo ser utilizados no âmbito da Patologia Comparada, quer para os Animais
Domésticos quer para o Homem.
ABSTRACT - Identification of Structural Proteins in Bovine Urinary Bladder Tumours - Bovine Enzootic Hematuria (BEH) is a disease characterized by a chronic progress associated with the ingestion of bracken fern (Pteridium aquilinum), which main characteristic is the development of urinary bladder tumours. This disease is endemic in different parts of the World where the appropriate conditions are settled for bracken fern upgrowth, including the Azores Archipelago. The objectives of this research were (i) the characterization by immunohistochemical methods of the expression of the uroplakin III (UPIII) and cytokeratin 7 (CK7), which are structural proteins of the urothelium, in carcinomas of the urinary bladder of animals affected by BEH, and its possible association with tumour grade and stage, (ii) the survey of the altered expression of the cell cycle regulating factors Cyclin D1 and p53 and its possible association with tumour grade and stage, (iii) evaluation of the applicability of bovine urinary bladder tumours as a model for urinary bladder tumours in Domestic Animals and in Humans. The results showed that loss of UPIII expression was seen in high grade and invasive urothelial carcinomas, and that this loss was statistically associated with both parameters. Similarly, the loss of CK7 expression was seen in high grade and invasive tumours and was statistically associated with high grade and invasion. The overexpression of Cyclin D1 was identified in urothelial carcinomas of all grades and stages and no statistical association was identified. Due to technical problems the evaluation of p53 overexpression was reduced to only 4 cases. Therefore, it was not possible to draw statistical significant associations. This research brings new data to the understanding of urinary bladder tumours allowing a better knowledge of the molecular changes involved and may be useful in the framework of Comparative Pathology, either for Domestic Animals or Humans.
ABSTRACT - Identification of Structural Proteins in Bovine Urinary Bladder Tumours - Bovine Enzootic Hematuria (BEH) is a disease characterized by a chronic progress associated with the ingestion of bracken fern (Pteridium aquilinum), which main characteristic is the development of urinary bladder tumours. This disease is endemic in different parts of the World where the appropriate conditions are settled for bracken fern upgrowth, including the Azores Archipelago. The objectives of this research were (i) the characterization by immunohistochemical methods of the expression of the uroplakin III (UPIII) and cytokeratin 7 (CK7), which are structural proteins of the urothelium, in carcinomas of the urinary bladder of animals affected by BEH, and its possible association with tumour grade and stage, (ii) the survey of the altered expression of the cell cycle regulating factors Cyclin D1 and p53 and its possible association with tumour grade and stage, (iii) evaluation of the applicability of bovine urinary bladder tumours as a model for urinary bladder tumours in Domestic Animals and in Humans. The results showed that loss of UPIII expression was seen in high grade and invasive urothelial carcinomas, and that this loss was statistically associated with both parameters. Similarly, the loss of CK7 expression was seen in high grade and invasive tumours and was statistically associated with high grade and invasion. The overexpression of Cyclin D1 was identified in urothelial carcinomas of all grades and stages and no statistical association was identified. Due to technical problems the evaluation of p53 overexpression was reduced to only 4 cases. Therefore, it was not possible to draw statistical significant associations. This research brings new data to the understanding of urinary bladder tumours allowing a better knowledge of the molecular changes involved and may be useful in the framework of Comparative Pathology, either for Domestic Animals or Humans.
Descrição
Dissertação de Mestrado Integrado em Medicina Veterinária
Palavras-chave
Tumores de bexiga Hematúria Enzoótica Bovina Proteínas estruturais Factores reguladores do ciclo celular Imuno-histoquímica Urinary bladder tumours Bovine Enzootic Hematuria Structural proteins Cell cycle regulating factors Immunohistochemistry
Contexto Educativo
Citação
Cota, J.B.B. (2011). Identificação de proteínas estruturais em tumores de bexiga de bovinos. Dissertação de Mestrado. Universidade Técnica de Lisboa, Faculdade de Medicina Veterinária, Lisboa.
Editora
Universidade Técnica de Lisboa. Faculdade de Medicina Veterinária