中国人散发性大肠癌中微卫星DNA不稳定的研究

Microsatellite Instability (MI) in Sporadic Colon of Tumor in Chinese

目的：探讨中国人散发性大肠癌中微卫星 Ｄ Ｎ Ａ 不稳定及复制差错与大肠癌生物学行为的关系。方法：选择１０ 个微卫星位点， 应用 Ｐ Ｃ Ｒ－ 变性聚丙烯酰胺凝胶电泳对３９ 例散发性大肠癌组织进行检测。结果：在多个位点上发现了较高的微卫星 Ｄ Ｎ Ａ 不稳定（ Ｍ Ｉ） ，其中 Ｄ３ Ｓ１３１７ 位点上 Ｍ Ｉ为４４ ％ ， Ｄ３ Ｓ９６６ 上 Ｍ Ｉ为２６ ．６ ％ ， Ｄ２ Ｓ１２３ 和 Ｄ２ Ｓ１１９ 上 Ｍ Ｉ分别为３６ ％ 和２５ ．７ ％ 。结论： Ｍ Ｉ阳性率和肿瘤组织学分类无明显相关性，而与肿瘤组织的分化程度、浸润程度等有显著的相关关系，因而微卫星 Ｄ Ｎ Ａ 可以为肿瘤的早期诊断及患者预后判断提供帮助。同时，在散发性结肠癌中也存在较高的微卫星 Ｄ Ｎ Ａ 不稳定，这可能与某种 Ｄ Ｎ Ａ 错配修复基因发生突变有关。

Objective: This paper aimed to investigate the relationship between the microsatellite instability and sporadic colon tumor by microsatellite markers in vitro . Method: PCR and denatured-polyacrylamide gel electrophoresis were used to detect and analyze 10 microsatellite DNA loci in 39 sporadic colon tumor tissues. Result: There was a high frequent MI at loci D3S1317 (44%), D2S123 (36%), D3S966 (26.6%) and D2S119 (25.7%). Conclusion: No statistically significant associations are found between MI and histotype, but there is a close relation of MI to tumor progression and differentiation. So MI can be used to provide useful information for early diagnosis of tumor, and the high frequent MI in sporadic cancer maybe result from the mutation of DNA mismatch repair gene.