Abstract:

OBJECTIVE: Tumor growth is regulated by a balance between proliferation, growth arrest and cell death. In this study, we have examined the expression of p27, cyclin D1, bcl-2, and bcl-x for evaluation of their roles in colon carcinoma progression. MATERIALS and METHODS: The levels of p27, cyclin D1, bcl-2, and bcl-x expression were examined by immunohistochemistry in transitional normal mucosa adjacent to adenomas (n=30), adenomas (n=30), transitional normal mucosa adjacent to adenocarcinomas (n=63), adenocarcinomas (n=63) and metastasis (n=16). Standard streptavidin-biotin immunperoxidase method was used for immunostaining and the stained slides were examined microscopically using semiquantitative criteria. RESULTS: Normal mucosa expressed p27 protein and adenocarcinomas displayed a decrease in the expression of this protein. Decreased expression of p27 was associated with tumor progression (p=0.026). Cyclin D1 staining was prominent in most of the adenocarcinomas and metastasis (p=0.042). Meanwhile, we could not find any relation between p27 and cyclin D1 expression. Bcl-2 and bcl-x expression also did not show any statistically significant correlation in tumor progression. CONCLUSION: The results of this study indicate that reduced p27 and cyclin D1 protein levels play an important role in progression of colon cancer. Bcl-2, and bcl-x expression were of no role.

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