[Expression of P27 protein and cyclin E in colon cancer].

Background & Objective: P27 protein and cyclin E were negative cell cycle regulators. Until the present, the influence of P27 protein and cyclin E on progression of colon cancer was unclear. The aim of this study was to observe the expression features of P27 protein and cyclin E in the tissues of colon neoplasms, and to investigate the relationship between colon neoplasms and tumor special growth factor (TSGF).

Methods: Sixty-nine cases of samples included 23 normal tissues, 28 colon polyps (13 inflammatory polyps and 15 adenomatous polyps), and 18 colon carcinomas. The location and expression of P27 protein and cyclin E were determined using immunohistochemical method in all samples. These samples were diagnosed using formal pathological techniques simultaneously; the relationship between colon neoplasms and TSGF was also investigated.

Results: The positive signal of P27 and cyclin E was found mainly in the cytoplasm and extracellular matrix of normal colon tissues, inflammatory polyps, and adenomatous polyps. Less amount of positive expression product of P27 protein and cyclin E was observed in colon carcinoma cells; and the positive signal was only located in the cytoplasm of gland-like cells. The content of TSGF in colon carcinoma tissues was significantly higher than that in normal tissues (117.3+/-57.02 versus 64.16+/-27.5,P< 0.01), but there was no significant difference between colon carcinoma tissues and inflammatory polyp tissues (117.3+/-57.02 versus 92.5+/-47.9,P >0.05).

Conclusion: P27 protein and cyclin E participate in the adjustment process of colon neoplasm occurrence and progression. The reduced expression of P27 protein and cyclin E may indicate the possibility of colon carcinoma.