ABSTRACT
Objective To investigate cortactin expression in malignant colorectal tissues and corresponding adjacent non-cancerous colon tissues,precancerous lesions (adenomatous polyps) and the relationship between the expression of cortactin and cell division in colorectal cancer cells.Methods The expression of cortactin was detected by immunohistochemistry in colorectal cancer,colorectal adenomatous polyp (precancerous lesions) and colorectal tissues adjacent to adenocarcinomas (normal tissues).Kaplan-Meier method was employed to compare the survival between the groups.Cortactin expression and cell division were detected by Western blot and immunofluorescence in SW-620 colon cancer cells treated with cortactin siRNA.Results The positive expression rate of cortactin was significantly higher in colorectal cancer tissues than in adenomatous polyp tissues and pericarcinomatous normal tissues.Overexpression of cortactin in colorectal cancer tissues was correlated with poor differentiation (P ＜ 0.01),lymph node metastasis (P =0.006),and TNM stage (P =0.022).The 5 year survival rate of the group of negative/weak positive expression of eortactin was significantly higher than the group of strong positive expression of cortactin.CTTN gene amplification in colorectal cancer tissues was obvious.Cortactin siRNA induction caused a lower cortactin protein expression in colorectal cancer cells.Conclusions It is suggested that the excessive expression of cortactin contributes to the growth of cancer cells in colorectal cancer.