Expression of p27Kip1 Protein in Colorectal Adenocarcinoma

ABSTRACT

p27Kip1 has been recognized as a negative regulator of cell cycle. Reduced level of p27 expression is associated with development and aggressiveness of several human tumors. To investigate the role of p27Kip1 on progression of colorectal adenocarcinoma, we studied 40 cases of human colorectal adenocarcinomas for expression of p27Kip1 protein using an immunohistochemical method, and compared these results with known prognostic parameters of colorectal adenocarcinoma. Among 40 cases of colorectal adenocarcinomas, p27Kip1 expression was detected in the nuclei of tumor cells in 14 cases (35%). The expression rate of p27Kip1 protein was significantly lower in the cases with lymph node metastasis (25.8%) than in those without lymph node metastasis (66.6%) (p<0.05). But it did not correlate with other parameters such as tumor size, histologic grade, vascular invasion, and Ki-67 labeling index. The results suggest that reduced expression of p27Kip1 protein plays a role in biologically aggressive behavior of colorectal adenocarcinoma.