目的:探讨微卫星DNA序列不稳定性(M SI)表达水平与人食管癌发生及其临床病理特征的关系。方法:应用聚合酶链反应(PCR)和变性聚丙烯酰胺凝胶电泳技术,对30例人食管癌中M SI表达情况进行研究。结果:D3S1067位点M SI发生检出频率较高,为26.7%(8/30);D18S58位点M SI阳性率为20%(6/30)。有18对组织在D3S1067和D18S58两个位点均未检出M SI。食管癌M SI多发生在3p位点,尤其是在3p14～3p21区段。食管鳞癌组织中M SI阳性为26.1%(6/23),差异有显著性(P<0.05),2例腺癌中1例检出M SI,5例食管小细胞癌均为M SI阳性。食管小细胞癌中M SI的发生较鳞癌为高,与肿瘤的病理分级、PTNM分期、有无区域淋巴结转移和浸润深度无关(P>0.05)。结论:食管癌在3p和18q染色体位点均存在微卫星不稳定现象;D3S1067和D18S582个位点上M SI与食管癌的临床病理类型均相关:D3S1067位点M SI与食管鳞癌的发生关系密切,D18S58与食管小细胞癌的发生关系密切;M SI也许可做为临床筛查恶性肿瘤高危人群的分子手段,具有潜在的应用前景。 Objective: To investigate the relationship between microsatellite DNA sequence instability (M SI) expression and the occurrence of human esophageal cancer and its clinicopathological features. Methods: The expression of M SI in 30 human esophageal carcinomas was studied by polymerase chain reaction (PCR) and denaturing polyacrylamide gel electrophoresis. Results: The frequency of M SI in D3S1067 was 26.7% (8/30), and the positive rate of M SI in D18S58 was 20% (6/30). 18 pairs of tissues did not detect M SI in both D3S1067 and D18S58 sites. Esophageal M SI occurs mostly in the 3p site, especially in the 3p14 ~ 3p21 region. The positive M SI in esophageal squamous cell carcinoma was 26.1% (6/23), with significant difference (P <0.05). M SI was detected in 1 of 2 adenocarcinomas and M SI in 5 cases of esophageal small cell carcinoma . M SI in esophageal small cell carcinoma was higher than that in squamous cell carcinoma, and had no correlation with tumor grade, PTNM stage, presence or absence of regional lymph node metastasis and invasion depth (P> 0.05). CONCLUSION: Microsatellite instability exists in the 3p and 18q chromosome sites of esophageal cancer. The M SI in D3S1067 and D18S582 sites is correlated with the clinicopathological types of esophageal cancer: the relationship between M SI at D3S1067 site and esophageal squamous cell carcinoma Closely, D18S58 is closely related to the occurrence of small cell carcinoma of the esophagus; M SI may be used as a molecular means for clinical screening of high-risk population of malignant tumors, which has potential application prospect.