非同位素PCR－SSCP分析检测结肠腺瘤与腺癌中K－ras基因改变

运用非同位素ＰＣＲ－ＳＳＣＰ分析检测结肠腺瘤与腺癌中Ｋ－ｒａｓ基因的改变，探讨该基因改变与结肠腺瘤不典型增生、结肠腺癌分期及分化程度之间的关系。结果显示，与自身正常及癌旁粘膜比较，２４例结肠腺场中，５例出现单链带的泳动变位，阳性率为２１％；１８例腺瘤中检出２例有单链带泳动变位，均为伴局部场变的腺瘤组织，提示当腺瘤发生ｒａｓ基因改变时，其恶性倾向增大。但结肠癌的分期及分化程度与ＰＣＲ－ＳＳＣＰ分析阳性率无明显相关性。增生性及幼年性息肉均未检出有改变。该法简便快速，不用同位素，可适用于临床标本检测。

Detection of K-ras gene alterations in colorectal adenomas and adenocarcinomas by nonisotopic PCR-SSCP analysis

The frequency of K-ras gene mutations in colorectal adenomas and adenocarcinomas was examined bynonisotopic PCR-SSCP analysis to investigate the relationship between mutations and dysplasia of colorec-tal adenomas,and between mutations and the stage and differentiation of adenocarcinomas for the purposeof providing evidence for the early diagnosis of colorectal cancer. The results show that of 24 cases of col-orectal carcinomas,5 had single-strand band mobility shift,the positive ratio was about 21%.2 of 18 casesof adenomas also had mobility shift. These 2 cases both had small focal cancerous area,indicating that whenadenomas had ras gene mutations,the potential of malignancy increased.There were no significant relation-ship between stage and differentiation of colorectal adenocarcinomas and PCR-SSCP analysis positive ratio.Inflammatory and juvenile polyps were all negative. This procedure is simple and rapid, no isotope wasneeded,so it may be possible for clinical use.