食管癌组织3p、18q位点微卫星DNA序列不稳定性的研究

Detection of microsatellite instability on chromosome 3p and 18q in esophageal carcinoma tissues

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 the microsatellite instability (MSI) and the clinical features in the esophageal cancer. Methods Thirty pairs of esophageal carcinoma and normal tissues were analyzed for the MSI expression by polymerase chain reaction (PCR) and denaturalized polyacrylamide gel electrophoresis technique.Results MSI was the most frequently observed at D3S1067 with an incidence of 26.7%(8/30). MSI at D18S58 was detected in 20%(6/30) of the tumors. Eighteen pairs of tissues had no MSI at either D3S1067 or D18S58. The frequent MSI in the esophageal cancer was observed at 3p, especially at 3p14-3p21. The MSI incidence in the squamous cell carcinoma tissues was 26.1%(6/23) with significant difference (P<0.01). MSI was detected in one out of two cases with adeno carcinoma and in all five cases with small cell carcinoma. MSI in the small cell carcinoma was more frequently seen than that in the squamous cell carcinoma. MSI at 3p and 18q has no significant relationship with the tumor stage, the cell differentiation, the invasive depth of the tumor tissues and the regional lymph node metastasis (P>0.05). Conclusions MSI in the esophageal carcinoma can be detected at both 3p and 18q loci. There lies correlation between MSI at either D3S1067 or D18S58 and the clinicopathologic characteristics with significant relationships between MSI at D3S1067 and squamous cell carcinoma and between MSI at D18S58 and small cell carcinoma. It seems MSI has no relationship with the tumor stages, the cell differentiation, the invasive depth of tumor tissue and the regional lymph node metastasis. The focus of 3p is hotly related with esophageal cancer. The gene changes at 3p play a notable role in the occurrence of the esophageal carcinoma. MSI appears to be a promising molecular index for the clinical screening in the population at risk of malignancy