RESUMO
BACKGROUND: Survivin is a member of the inhibitor of an apoptosis protein family that has been shown to inhibit apoptosis, promote cell proliferation and enhance angiogenesis. In this study, the survivin protein expression in normal, colon polyp, and adenocarcinoma tissues was investigated. METHODS: Immunohistochemical staining for nuclear survivin was carried out on 45 normal colon tissue samples, 38 samples of a colonic polyp, and 37 cases of colon adenocarcinoma operated by colonoscopy or colectomy. The percentages of cells that expressed survivin were classified qualitatively into four categories (0, 1+, 2+, and 3+) based on the intensity of staining and the percentage of cells. An area of samples with colon polyp diagnosis or colon adenocarcinoma that had no microscopic pathology was considered as normal tissues. RESULTS: Survivin protein expression was negative in all cases of normal colon tissue samples while it was expressed in 31 out of 38 colon polyp specimens (81.5%) and in 35 out of 37 (94.5%) colon adenocarcinoma samples. Amount of expression in the colon adenocarcinoma (p < 0.001) was significantly higher than the amount of expression in the colon polyp. There was not a significant correlation between the survivin protein expression and the low and high grade adenocarcinoma (p = 0.874). CONCLUSIONS: Survivin protein was not expressed in normal colon tissues and its amount was higher in the colonic adenocarcinoma compared to the colon polyp. Due to the variations in the intensity of expression in colon polyp (changing from negative to + 3), this marker cannot be used for differentiating the polyp from the adenocarcinoma.
