PCR-SSCP法检测大肠肿瘤APC基因MCR区段基因突变

Detection of APC Gene Mutations in Colorectal Neoplasms with PCR-SSCP Analysis

目的：检测 ＡＰＣ（adenomatous polyposis coli）基因在国人大肠肿瘤中的突变情况，探讨ＡＰＣ基因突变与大肠肿瘤病理学特征的关系。同时探讨单链ＤＮＡ 碱基构成与最适ＳＳＣＰ电泳温度的关系。方法：应用聚合酶链反应-单链构象多态（ＰＣＲ－ＳＳＣＰ）技术对６６例散发性大肠癌、17例大肠腺瘤性息肉、４例家族性腺瘤性息肉病（familial adenomatous polyposis,polyposis ,ＦＡＰ）ＡＰＣ基因第１５外显子ＭＣＲ区段的突变进行检测。结果：散发性大肠癌和腺瘤性息肉ＡＰＣ基因突变率分别为２１．２％（１４／６６）和２３．５％（４／１７），两者差异无显著性。散发性大肠癌ＡＰＣ基因突变与肿瘤的位置、浸润深度、组织类型、分化程度、分期以及淋巴结转移无关。ＭＣＲ区段中以密码子１３３７～１４５３区域突变率最高。结论：ＡＰＣ基因突变是大肠肿瘤发生的早期事件。ＳＳＣＰ最适温度与ＤＮＡ片段正链Ｃ/A值成正相关。

Objective: To investigate APC (adenomatous polyposis coli) gene mutations in spo- radic colorectal neoplasms and their relation to clinicopathological features and study the correla- tion between the basic constitution of single strend DNA and the optimal eletrophoretic tempera- ture for SSCP. Methods: Mutations were screened with polymerase chain reaction-single strand conformation polymorphisms (PCR--SSCP) technique improved by us. The mutation cluster re- gion (MCR) of the APC gene was analysed in 66 cases of sporadic colorectal carcinomas, 17 cases of adenomas and 4 cases of FAPs. Results: Mutations in MCR of APC gene were found in 21. 2% (14/66 )sporadic colorectal carcinomas and 23. 5 % (4/l7 )adenomas. The difference in mutation frequency between the two groups was not statistically significant(P>0.05). There was no re- lationship between the mutation frequency and the clinicopathological features. Conclusion: The APC gene mutation is an early event in colorectal tumorigenesis. The optimal eletrophoretic tem- perature for SSCP is positively correlative to C/A ratio of sense strend.