ABSTRACT
Objective To investigate the relationship between p27 gene methylation and pathology of colorectal carcinoma. Methods p27 gene methylation promotor region and p27 protein expression were detected respectively by methylation specificity polymerase chain reaction and immunohistochemical staining SP in 106 cases of colorectal carcinoma and each adjacent normal mucous membrane tissue and 22 cases of colorectal adenoma tissue. Results The positive expression rate of p27 gene methylation was statistically different in colorectal carcinoma tissue compared with normal mucous membrane and colorectal adenoma tissue (P＜0.05). Their positive expression rate were 59.4% (63/106), 18.2% (4/22) and 3.8%(4/106) respectively in colorectal carcinoma tissue,colorectal adenoma and normal mucous membrane tissue (P ＜ 0. 05). p27 gene methylation in poorly differentiated group was significantly higher than that in welldifferentiated group (48.0% vs. 24. 7%, P ＜0. 05), in Dukes-A + B stage group was significantly lower than that in Dukes C + D stage group(20. 0% vs. 41.2%, P ＜ 0. 05 ), and it was higher in lymph nodes metastases group than that in lymph nodes negative group(41.5% vs. 23. 1%, P ＜0. 05), that in positive serosa infiltration group was higher than negative serosa infiltration group(32. 5% vs. 24. 1%, P ＞ 0. 05 ).Conclusions Methylated p27 gene protein expression in colorectal carcinoma was significantly higher than normal mucous membrane and colorectal adenoma tissue. The methylation rate of p27 gene in colorectal carcinoma was significantly associated with tumor differentiation, invasive depth, Dukes stage, lymph node metastasis.