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Purposes: 1, detected in normal mucosa, colorectal adenomas, large colorectal p16 of hMLH1 gene CpG island methylation status, to evaluate the role and clinical significance in colorectal carcinogenesis. Detect normal stick mold, serrated adenoma, non-serrated adenoma, colorectal cancer, BRAF, β-catenin, COX-2 expression in the case of BRAF in colorectal carcinogenesis. Methods: 1, the collection of the Sichuan Provincial People's Hospital in October 2008-December 60 cases of surgical and endoscopic biopsy specimens, including 20 cases of colorectal cancer and adenoma 20 cases, 20 cases of normal tissue. Specific methylation PCR (MSP) was used to detect p16, hMLH1 gene methylation status of CpG islands. Collect the Sichuan Provincial People's Hospital, June 2008-December 50 cases of paraffin-embedded tissue specimens, including 20 cases of colorectal cancer specimens serrated adenoma 10 cases, 10 cases of non-serrated adenoma, 10 cases of normal intestinal stick mold by immunohistochemistry (IHC) Simultaneous Detection of BRAF, β-catenin, COX-2 protein expression. The results: 1, MSP method detected the start of p16 promoter CpG island methylation positive expression rate was 30% (6/20 cases), adenoma and normal tissue does not detect the p16 gene CpG island methylation in colorectal cancer. Colorectal cancer and adenoma group, between the normal group, a significant difference (p = 0.020,0.020) and between adenoma group and the normal group, no significant difference (p> 0.05). hMLH1 promoter CpG island methylation positive expression rates of colorectal cancer and adenoma in 25% (5/20 cases), 10% (2/20), and was not detected in normal tissue the hMLH1 gene CpG island A Residues. Between colorectal cancer and the normal group, a significant difference (p = 0.047), and no significant difference (p> 0.05) between the other groups. p16, hMLH1 CpG island methylation with Dukes stage, tumor size, lymph node metastasis, the relationship between the degree of differentiation between statistically significant (p <0.05), no statistically significant relationship between gender and tumor site ( p> 0.05). Immunohistochemistry (IHC) method detected: BRAF protein in colorectal carcinoma, serrated adenoma, non-serrated adenoma, normal tissue positive expression rate of 80% (16/20 patients), 100% ( 10/10 patients), 40% (4/10 cases), 10% (1/10 patients), BRAF protein expression between BRAF protein expression in colorectal serrated adenoma and non-serrated adenoma and normal tissue There are significant differences (p <0.05); positive expression rate of β-catenin in colorectal serrated adenoma, non-serrated adenoma, normal tissue were 70% (14/20 patients), 50% (5 / 10 patients), 60% (6/10), 0% (0/10 cases). Significant difference (p <0.05); COX-2 in colorectal serrated adenoma, non-serrated glandular colorectal serrated adenoma and serrated adenoma β-catenin protein expression between normal tissue The positive expression rate in the tumor and normal tissue in 90% (18/20 patients), 100% (10/10 patients), 70% (7/10), 0% (0/10). Significant difference (p <0.05) between colorectal serrated adenoma, non-serrated adenoma COX-2 protein expression in normal tissue. Conclusion: 1, p16, the the hMLH1 promoter CpG island methylation is important genetic events that promote colorectal carcinogenesis. 2, p16, hMLH1 gene methylation Duke may be associated with colorectal cancer staging. BRAF, β-catenin, high expression of COX2 protein and colorectal cancer occurred related. BRAF protein expression may be the serrated adenoma characteristic changes.
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