ABSTRACT
Objective:To determine whether CD46, CD55, and CD59 are differentially expressed in neoplastic and adjacent nor-mal colon tissues and to investigate their influence on clinicopathologic variables. Methods:Immunohistochemistry (a modified two-step method) was used to detect the expression of CD46, CD55, and CD59 in a tissue microarray of 121 cases of colon cancer and corre-sponding adjacent non-tumor tissues with detailed clinical information, including gender, age, differentiation, TNM classification, tu-mor location, and tumor histotype. The colon carcinoma microarray was constructed from patients' samples obtained from the Depart-ment of Gastrointestinal Surgery of Xijing Hospital of the Fourth Military Medical University between October 2004 and June 2006. The correlation between expression and clinicopathologic features was analyzed. Results:The expression levels of CD46, CD55, and CD59 were significantly higher in colon cancer tissues compared with those in normal adjacent colon tissues (P0.05). The expression levels of CD55 and CD59 were correlated with the grade of colon cancer differentiation. Low levels of CD55 and CD59 were detected in cancer cells of highly differentiated cancer, whereas stronger staining for CD55 and CD59 was mainly observed in cancer cells of moderately and poorly differentiated colon cancer (P<0.05). In addition, the expression levels of CD55 and CD59 were higher in stages III and IV colon cancer than those in stages I and II according to TNM classification (P<0.05). Conclusion:CD46, CD55, and CD59 are up-regulated in colon cancer. Specifically, CD55 and CD59 are of clinical relevance to differentiation and TNM staging of colon cancer, and their expression might be closely related to clinical biological behaviors.