MAD2和p16在大肠癌中的表达及意义

 目的 了解大肠癌中MAD2和p16的表达，探寻在大肠癌、腺瘤及正常大肠黏膜组织中的表达差异，初步分析其临床意义。方法 通过实时荧光定量PCR和免疫组织化学方法检测大肠癌、腺瘤及正常大肠黏膜组织中MAD2表达，并对大肠癌组织中MAD2扩增产物进行测序。同时利用免疫组织化学方法检测大肠癌和正常组织中p16的表达。结果 大肠癌组织中MAD2的阳性表达明显高于腺瘤和正常大肠黏膜组织（66.7％vs. 39.6％vs. 22.9％），三者比较差异有统计学意义（P＜0.001）。MAD2表达与肿瘤分化和无瘤生存时间有关（P＜0.05）。大肠癌组织中未见MAD2基因突变。正常大肠黏膜组织中p16阳性表达率为16.7%，大肠癌中阳性表达率为47.9％，两者比较差异有统计学意义（P＜0.05）。结论 基因MAD2和p16表达异常是大肠癌产生的机制之一，与大肠癌的发生及发展有关。MAD2可能是大肠癌预后的一种重要预测指标。

Expression of MAD2 and p16 in Colorectal Cancer and Clinical Significance

To study the expression of MAD2 and p16 gene in colorectal cancer and to demonstrate the relation between the expression of MAD2 and p16 in colorectal cancer，adenoma and normal tissue and to evaluate their clinical significances. Methods Immunohistochemistry method and real-time fluorescence quantitative PCR were used to analyze the expression of MAD2 in the colorectal cancer，adenoma and normal tissue. PCR amplification and DNA sequencing were performed to detect the mutations of MAD2. p16 was determined in the colorectal cancer and normal tissue by immunohistochemistry methods. Results The expression of MAD2 in colorectal cancer were obviously higher than that in adenoma and normal tissue（66.7％vs. 39.6％vs. 22.9％）. There were obvious difference among colorectal cancers，adenoma and normal tissue （P＜0.001），and it were related to tumor differentiation and survival time （P＜0.05）. No mutation of MAD2 gene was found in colorectal cancer. The rate of p16 positive expression in colorectal cancer and normal mucosa was 47.9%and 16.7%，respectively. There was significant difference between normal mucosa tissue and colorectal cancers（P＜0.001）. Conclusion Our data indicates that positive expression of MAD2 and p16 was mainly involved in colorectal carcinogenesis and MAD2 was associated with prognosis of colorectal cancer.