直肠癌切缘黏膜组织p53基因370位点甲基化的表达

The detection of methylation on the K370 site of p53 gene in the recurrance of anastomotic stoma of rectum cancer

目的检测直肠癌下切缘中黏膜p53基因K370位点甲基化表达，探讨“分子界定”的临床意义，评估p53基因370位点甲基化与安全切缘的关系。方法选取2000年1月至2007年7月在武汉大学人民医院外科确诊并接受直肠癌前切除术治疗的直肠癌患者197例，术后1～3年吻合口复发的46例，未复发151例，同时取20例正常直肠黏膜标本作为阴性对照。根据复发的情况，分为复发组、未复发组以及对照组。用免疫组织化学法检测p53蛋白表达应用免疫组织化学技术检测切缘组织中p53蛋白的表达。用甲基化特异性聚合酶链反应（MSP）技术，检测切缘组织中p53基因K370位点甲基化，并通过Pearson统计学方法分析两者的相关性。同时统计各组患者年龄、性别、肿瘤大小、临床分期等差异是否有统计学意义。结果复发组、未复发组及对照组织切缘标本p53蛋白表达差异无统计学意义（P〉0．05）。所有46例复发组中有41例发生甲基化，甲基化率为89．1％，未复发组（12／115例）和对照组m现低甲基化和未发现甲基化，两组间差异有统计学意义（P〈0．01）。复发组K370位点甲基化率高于未复发组。K370的甲基化率在肿瘤直径和距肛缘距离以及TNM分期方面差异有统计学意义（P〈0．01），但是，在患者年龄、性别方面差异无统计学意义（P〉0．05）。结论p53基因的K370位点甲基化可以作为安全切缘指标和预测局部复发、远处转移和生存率的预后指标的标准，准确评估K370位点甲基化有利于合理选择安全切缘。

Objective To detect methylation of the K370 site of p53 gene on the down-incisal margin in the patients of rectum cancer, in order to explore the clinical significance of ineisal margin decided by molecule and to analyze relationships between the safety-ineisal margin and Methylation of the K370 site of p53 geue. Methods 197 operated patients of rectum cancer were selected from 2000 to 2007.46 patients have suffered from reeurranee of anastomotic stoma after 1-3 years, and non-recurrence with 151 cases. 20 cases of normal people were control group. The p53 protein on the ineisal margin were detected with immunohistochemical method, and methylation specific polymerease chain reaction （MSP） were used to detect the expression of Methylation on the K370 site of p53 gene on the same tissues. The relationships were analyzed by the Pearson statistical method. Results After detecting the expression of p53 protein on the margin, there were non-statistics significant difference between the recurrance and non-recurrence, control group each other （P 〉 0. 05 ）. There were 41 cases with K370 methylation among 46 patients （ 89. 1% ）. Compared with the rates of methylation of non-recurrence group, there was statistics significant difference between the reeurranee and non-recurrence group each other （ P 〈 0.01 ）. K370 methylation rate had statistics significant difference between pathology advances, size of tumor and distance from anus （ P 〈 0. 05 ） , their methylation rate were non-statistics significant difference age and sex. Conclusion Methyla- tion on the K370 position of p53 gene is closely related with safety-incisal margin. Detection of Methylation on the K370 position of p53 geue are helpful for determination of safety-ineisal margin, will provide the basis for clinical treatment.