Avaliação da associação entre a presença de polimorfismo no gene da metaloproeinase-9 e o desenvolvimento do carcinoma espinocelular quimicamente induzido pelo DMBA na pele de camundongos hairless
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Data
2007-07-18
Autores
Pereira, Andresa Costa [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
Para que ocorra a invasão das células epiteliais neoplásicas é necessário o rompimento da membrana basal, sendo que este processo depende, em grande parte, da ação enzimática realizada pela metaloproteinase-9 (MMP-9). O objetivo deste trabalho foi testar a hipótese que variações no gene da MMP-9 influenciam as características clínicas e histopatológicas do carcinoma espinocelular. Noventa e quatro camundongos hairless foram submetidos à carcinogênese química (DMBA 0,5%) induzida em pele, durante 16 semanas. Na 17ª semana, os animais foram sacrificados e as lesões fotografadas e avaliadas clinicamente (com relação ao tamanho e à presença de ulceração). As lesões foram então biopsiadas e fixadas em formaldeído 10%, para posterior avaliação histopatológica (padrão de invasão, estágio de invasão e diferenciação celular). No momento da biópsia, foi retirado 0,5 cm da cauda de cada animal, para extração do DNA e avaliação da presença de polimorfismos de repetição CA no promotor do gene da MMP-9. Foi utilizado o teste qui-quadrado (p<0,05) para avaliar a associação dos alelos e dos genótipos com as características clínicas e histopatológicas. Verificou-se uma associação entre o alelo com 25 repetições e o grau moderado de diferenciação celular. Concluiu-se que a presença de maior número de repetições CA no gene da MMP-9 pode estar relacionada com a redução na diferenciação celular do carcinoma espinocelular induzido quimicamente na pele de camundongos hairless.
The metalloproteinase-9 (MMP-9) is an important enzyme during the basement membrane degradation, an essential step for cancer invasion. The aim of this study was to test the hypothesis that the CA repeat polymorphism in the MMP-9 gene promoter interferes on clinical and histopathological features of the squamous cell carcinoma. Ninety-four hairless mice were submitted to chemically induced skin carcinogenesis (DMBA 0,5%), once a week, during 16 weeks. At 17 th week, the animals were photographed and the lesions were clinically evaluated (for size and ulceration presence). Then, the lesions were biopsed and, after the routine laboratorial processing, the histopathological evaluation (stage of invasion, pattern of invasion and differentiation grade) was performed. At the biopsy, 0.5cm of each animal tail was collected for DNA extraction and evaluation of the CA repeat polymorphism in the MMP-9 gene promoter. The data was analyzed by chi-square test to evaluate whether the MMP-9 alleles or genotypes were associated with clinical and histopathological features. There was an association of the allele with 25 CA repeats with moderately differentiated lesions. The data suggest that the MMP-9 gene polymorphism is related to the reduction on histological differentiation in squamous cell carcinoma induced by DMBA in hairless mice skin.
The metalloproteinase-9 (MMP-9) is an important enzyme during the basement membrane degradation, an essential step for cancer invasion. The aim of this study was to test the hypothesis that the CA repeat polymorphism in the MMP-9 gene promoter interferes on clinical and histopathological features of the squamous cell carcinoma. Ninety-four hairless mice were submitted to chemically induced skin carcinogenesis (DMBA 0,5%), once a week, during 16 weeks. At 17 th week, the animals were photographed and the lesions were clinically evaluated (for size and ulceration presence). Then, the lesions were biopsed and, after the routine laboratorial processing, the histopathological evaluation (stage of invasion, pattern of invasion and differentiation grade) was performed. At the biopsy, 0.5cm of each animal tail was collected for DNA extraction and evaluation of the CA repeat polymorphism in the MMP-9 gene promoter. The data was analyzed by chi-square test to evaluate whether the MMP-9 alleles or genotypes were associated with clinical and histopathological features. There was an association of the allele with 25 CA repeats with moderately differentiated lesions. The data suggest that the MMP-9 gene polymorphism is related to the reduction on histological differentiation in squamous cell carcinoma induced by DMBA in hairless mice skin.
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Palavras-chave
Carcinoma de celulas escamosas, Polimorfismo (Genetica), Metaloproteinase 9 da matriz
Como citar
PEREIRA, Andresa Costa. Avaliação da associação entre a presença de polimorfismo no gene da metaloproeinase-9 e o desenvolvimento do carcinoma espinocelular quimicamente induzido pelo DMBA na pele de camundongos hairless. 2007. 83 f. Tese (doutorado) - Universidade Estadual Paulista, Faculdade de Odontologia de São José dos Campos, 2007.