Published online Sep 15, 2003. doi: 10.3748/wjg.v9.i9.1972
Revised: April 23, 2003
Accepted: May 21, 2003
Published online: September 15, 2003
AIM: To investigate the expression of tumor suppressor gene p53 and spindle checkpoint gene Mad2, and to demonstrate their expression difference in colorectal cancer and normal mucosa and to evaluate its clinical significance.
METHODS: Western blot and immunohistochemistry methods were used to analyze the expression of Mad2 in colorectal cancer and its corresponding normal mucosa. The expression of p53 was detected by immunohistochemistry method in colorectal cancer and its corresponding normal mucosa.
RESULTS: Mad2 was significantly overexpressed in colorectal cancer compared with corresponding normal mucosa (P < 0.001), and it was not related to the differentiation of adenocarcinoma and other clinical factors (P > 0.05).The ratio of Mad2 protein in cancer tissue (C) to that in its normal mucosa tissue (N) was higher than 2, which was more frequently observed in patients with lymph gland metastasis (P < 0.05). p53 protein expression was not observed in normal mucosa. The rate of p53 positive expression in adenocarcinomas was 52.6%. There was a significant difference between adenocarcinomas and normal mucosa(P < 0.001), which was not related to the differentiation degree of adenocarcinoma and other clinical factors (P > 0.05).
CONCLUSION: Defect of spindle checkpoint gene Mad2 and mutation of p53 gene are involved mainly in colorectal carcinogenesis and C/N > 2 is associated with prognosis of colorectal cancer.