Imunoexpressão das proteínas COX-2, p53 e caspase-3 em adenoma colorretal e mucosa não neoplásica

• Autor(a) principal: Nogueira, Renan Brito [UNIFESP]
• Data de Publicação: 2013
• Outros Autores: Pires, Andréa Rodrigues Cordovil, Soares, Thélia Maria Santos, Rodrigues, Simone Rabello De Souza, Campos, Mariane Antonieta Menino, Toloi, Giovanna Canato, Waisberg, Jaques
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Repositório Institucional da UNIFESP
• Texto Completo: http://dx.doi.org/10.1590/S1679-45082013000400009; http://repositorio.unifesp.br/handle/11600/8080
• topic: Adenoma; Immunohistochemistry; Gene, p53; Caspase 3; Cyclooxygenase 2; Intestine, large; Adenoma; Imunoistoquímica; Genes p53; Caspase 3; Ciclo-oxigenase 2; Intestino grosso

OBJECTIVE: To analyze the immunoexpression of the COX-2, p53, and caspase-3 proteins in colorectal adenomas and non-neoplastic mucosa. METHODS: 72 individuals were subjected to colonoscopy, which provided 50 samples of adenomas and 45 samples of non-neoplastic colorectal mucosa. The tissue samples were obtained via the tissue microarray technique and subjected to immunohistochemical analysis using primary anti-p53, anti-COX-2, and anti-caspase-3 antibodies. The positivity and intensity of the immunoreaction were classified. The analyzed variables were as follows: site of the adenomas in the colon, degree of dysplasia, size, and score of positivity and intensity of immunoexpression of the p-53, caspase-3, and COX-2 proteins. RESULTS: The immunoexpression of mutated protein p53 was positive in 30 (60%) adenoma samples and negative in 20 (40%) adenoma samples. The immunoexpression of mutated protein p53 was negative in 39 (86.6%) samples and positive in 6 (13.3%) samples of the non-neoplastic colorectal mucosa (p<0.0001). Significant differences were seen between both the largest size (p=0.006) and the highest degree of dysplasia (p<0.0001) of the adenomas and the intensity of immunoexpression of mutated protein p53. The positivity and intensity of immunoexpression of COX-2 (p=0.14) and caspase-3 (p=0.23) showed no significant differences between the adenomas and the non-neoplastic colorectal mucosa. CONCLUSION: Mutated protein p53 was hyperexpressed in the adenomas compared with the non-neoplastic mucosa. Greater size and greater degree of dysplasia in the adenomas were associated with higher expression of mutated protein p53. The immunoexpression of COX-2 and caspase-3 in the adenomas did not exhibit a correlation with the anatomical-pathological features of the tumors and did not differ from the corresponding expression levels in the non-neoplastic mucosa.