MICA 第5 外显子微卫星多态性与食管癌相关性研究

目的:研究MICA 第5 外显子微卫星多态性与食管癌相关性。方法:采用PCR-STR 微卫星基因分型技术检测103 例食管癌患者和84 例正常对照MICA 基因5 外显子多态性。构建食管癌标本中高频率出现的MICA 等位基因的真核表达载体,转染293T 细胞株,LDH 法检测NK 细胞对不同MICA 等位基因转染的293T 细胞的杀伤作用,效靶比20 1。ELISA法检测转染的293T 细胞上清中sMICA 含量。结果:食管癌患者第5 外显子检测到5 种等位基因,频率分别为:MICA-A4(9.71%),MICA-A5(22.3%),MICA-A5.1(40.8%),MICA-A6(15.5%),MICA-A9(11.7%),其中MICA-A5.1 与对照组对比差异有统计学意义(P<0.05)。MICA 等位基因转染293T 细胞株后,相对于其他第5 外显子A5.1 组对NK 杀伤的敏感性较低[(30.4±6.3)%,P<0.05],上清可溶性MICA 分泌增加(135.7±6.2)pg/ ml。结论:食管癌与MICA 第5 外显子多态性A5.1 显著性相关,其危险性高于其他等位基因。

Association of microsatellite polymorphism of MICA gene with susceptibility to esophageal cancer

Objective:To explore the association of microsatellite polymorphism of MICA gene with susceptibility to esophageal cancer.Methods: PCR-STR microsatellite genotyped technique was used to detect the polymorphism of MICA in Exon 5 in 103 cases of esophageal cancer and 84 cases of normal controls.Constructed of eukaryotic expression vector in esophageal carcinoma with high frequency of occurrence of the MICA allele.NK cells killing effect to 293T cells after alleles MICA transfected were assayed by LDH and the effect on target was 20 1.ELISA was used to test supernatants sMICA of 293T cell after transfected.Results: Identified five allelic genes in MICA Exon 5 with esophageal cancer.Each allele and its frequency respectively were:MICA-A4(9.71%),MICA-A5(22.3%),MICA-A5.1(40.8%),MICA-A6(15.5%),MICA-A9(11.7%).MICA-A5.1 showed significant difference comparison with the control group.After 293T cell line was transfected MICA allele,MICA-A5 1 group was less sensitive to NK cytotoxicity compared to other groups[(30.4±6.3)%,P <0.05].The secretion of soluble MICA increased(135.7±6.2) pg/ ml.Conclusion:Esophageal cancer was relevent with the MICA-A5.1 polymorphism of MICA Exon 5 alleles.Its risk is higher than other alleles.