Rap1GAP Expression And Its Methylation Level In Colon Cancer

Objective:Colorectal cancer is one of common malignant tumors of digestive system, in recent years, most research shows, global colon cancer incidence rate is rising, and tends to be younger. In general colon cancer onset occult, asymptomatic or in early symptoms are not typical, easy to be ignored, thus affecting the early diagnosis and treatment, when found metastasis has occurred, lost the chance of radical, seriously affecting the prognosis. So seek the tumor invasion, metastasis mechanism, to inhibit tumor invasion, metastasis is the hot spot in tumor research. In recent years, molecular biology and the apparent development and applications of genetics, found a lot of tumor invasion and metastasis the relevant genes and the possible mechanism of the effect. As a tumor suppressor gene,expression of Rap1 GAP in the majority of tumor was significantly down regulated the expression of tumor suppressor gene, and its function match, it is due to the reduced expression of tumor suppressor gene contributing to the occurrence and development of tumor. With the in-depth study of epigenetics, in tumor suppressor gene expression regulation mechanism, the relationship between Rap1 GAP promoter methylation and cancer has been paid more and more attention. This paper through the application of immunohistochemistry and quantitative methylation of PCR(quantitative methylationspecific PCR, q--MSP) detecting colon cancer Rap1 GAP expression and promoter methylation status and significance, aiming for the early diagnosis of colon cancer, targeted therapy, anti multidrug resistance so as to provide theoretical basis and research direction.Methods:Immunohistochemistry technique to detect the expression of Rap1GAP; the expression of Rap1 GAP between the groups; using quantitative methylation of PCR(quantitative methylation specific PCR, q--MSP) in detecting Rap1 GAP gene promotermethylation level sub area. The comparison of the differences between the groups of Rap1 GAP gene promoter region methylation level.Results:The expression of Rap1 GAP protein in colon cancer tissues than in normal tissues adjacent to carcinoma and colonic adenomas were decreased(P < 0.05), the difference was not statistically significant expression in colorectal adenoma and cancer adjacent normal tissues. The rate of methyl group was significantly higher than that of colon cancer colon adenoma group and normal tissues adjacent to carcinoma group, the difference was statistically significant(P < 0.05).Conclusions:The tumor suppressor gene Rap1 GAP in the progression of colorectal cancer. Low expression of Rap1 GAP and Rap1 GAP protein promoter hypermethylationrelated.Hypermethylation of Rap1 GAP promoter might be used as a target for early detection of colon cancer.