대한대장항문학회

Purpose: The cyclin-dependent kinase inhibitor p27<sup>kip1</sup> protein is a negative regulator of the cell division cycle, and its degradation is required for entry into the S phase. Loss of p27<sup>kip1</sup> protein expression has been<br>reported to<br>be associated with aggressive behavior in a variety of tumors of epithelial and lymphoid origin. The purpose of this study was to determine the expression of p27 protein in adenoma and adenocarcinoma of the colorectum and to assess the prognostic<br>significance.<br>Methods: We performed immunohistochemical staining for expression of p27 protein in adenomas (20 cases) and adenocarcinomas (30 cases) of the colorectum. The data (p27 protein labeling index (LI, mean standard deviation)) were analyzed in<br>association<br>with clinicopathologic parameters.<br>Results: p27 protein LI of normal mucosa (10 cases), adenoma, and adenocarcinoma were 93.3 4.5, 65.4 17.5, and 28.2 14.5, respectively (p＜0.0001). p27 protein LI of well differentiated adenocarcinoma was slightly higher than those of moderately<br>and/or<br>poorly differentiated adenocarcinoma, but did not show any significant difference among these groups (p=0.19). Also p27 protein expression did not show any significant relationship to other prognostic facters such as age, invasion depth, and<br>operative<br>staging.<br>Conclusions: The results suggested that reduced expression of p27 protein may play an important role in the malignant transformation process of colorectal cancer.<br>