Study On Methylation Of APC And MGMT Gene In TCM Syndrome

BackgroundIntestinal polyp is a kind of common disease, As the changes in eating habits and the popularity of colonoscopy, the detection rate of intestinal polyps is showed by an increasing trend. At present a lot of studies suggest that tubular adenomatous polyp and villous adenoma polyp are precancerous lesions, which confirmed the occurrence of colon polyps and colon cancer are inseparable. Although cancerous mechanisms of intestinal polyps is unclear, but more and more scholars recognize the theory of sequential occurrence of colorectal adenoma-cancer.As the colorectal cancer becoming the third cause of death, and age of cancer onset becoming more younger, the cancerous mechanism of intestinal polyp has also been a research hotspot at home and abroad.The studies on intestinal polyps at home and abroad are about diagnosis, treatments and pathological types by endoscopic, occurrence regularity of intestinal polyp in the level of cell and molecular biology. But study to explore the etiology,pathogenesis,syndrome differentiation and treatment of intestinal polyps from TCM is less,the development mechanism of intestinal polyps from field of epigenetics of methylation is more rare.ObjectiveTo conduct a epidemiological investigation of traditional Chinese medicine (TCM) in patients with intestinal polyps in Yangzhou region and observe the role and clinical significance of the adenomatous polyposis coli (adenomatous polyposis coli, APC) gene, and6-O methylguanine-DNA methyltransferase gene (O6-methylguanine-DNA methyltransferase, MGMT) hypermethylation in intestinal polyps. Methods To conduct epidemiological research of TCM with168cases with colorectal polyps diagnosed by colonoscopy at the Gastroenterology Clinic of Subei People’s Hospital of Jiangsu province from April2010to July2012.40cases of intestinal polyps,15cases of colorectal carcinoma,15cases of normal intestinal tissue were collected and detected APC gene and MGMT gene promoter hypermethylation by methylation-specific polymerase chain reaction (methylation-specific PCR, MSP). Analyze the data with SPSS10.0, standards for the p<0.05was considered statistically significant.Results:Comparison of age, sex in TCM and Western pathological syndromes TCM in intestinal polyps are mainly five categories: the type of weakness of the spleen in81cases (accounting for48.20%), dampness-heat of large intestine syndrome in43cases (25.6%), stagnation of liver Qi in29cases (17.3%), the type of blood stasis within the stop in7cases (4.2%), pathogenic cold internal resistance in8cases (4.8%).The type of weakness of the spleen and dampness-heat of large intestine syndrome are more common. Western pathological type of intestinal polyps:adenomatous polyps in122cases (72.6%), non-adenomatous polyps in46cases (27.4%), including42cases of inflammatory polyps,3cases of hyperplastic polyps,1case of juvenile polyps. Adenomatous polyps are more common. TCM and Western pathological syndromes in Intestinal polyps were no significant difference (p>0.05). Different ages in TCM were no significant difference (p>0.05), different ages in western pathological type were significantly difference(p<0.05). Gender in TCM or Western pathological types were not significantly difference (p>0.05).Methylation rate of APC and MGMT in each groupThe group of intestinal polyp and groyp of colorectal carcinoma both had APC gene hypermethylation, their positive rates were55%and60%respectively, and significantly higher than the group of normal intestinal tissue (P<0.01). The group of polyp and group of colorectal cancer had no significant difference. The group of intestinal polyps and group of colorectal carcinoma had MGMT gene hypermethylation, positive rates were respectively32.5%and40%, significantly higher than the group of normal intestinal tissue (P<0.05). but the group of polyps and group of colorectal cancer had no significant difference.Conclusionl.TCM of colorectal polyps are the type of weakness of the spleen, dampness-heat of large intestine syndrome, stagnation of liver Qi, the type of blood stasis within the stop, pathogenic cold internal resistance.The type of weakness of the spleen and dampness-heat of large intestine syndrome are more common. The common pathological type is the Adenomatous polyp.2.MGMT gene methylation may be involved in the evolution of colorectal adenomas to adenocarcinoma, and may be an early event of colorectal cancer.3.APC gene hypermethylation was the primary mechanism of tumor suppressor gene inactivation, and was closely related to the development and occurrence of colorectal cancer and adenoma. It was also the reference index to be used as the early diagnosis and prognosis evaluation of colorectal cancer.