PTEN基因甲基化及其表达异常与胃癌的关系分析

目的探讨PTEN基因甲基化及其表达异常与胃癌的关系。方法从我院选取120例胃癌患者作为临床研究对象。对患者PTEN基因甲基化及其表达异常情况进行分析,并探讨PTEN基因甲基化以及PTEN基因表达异常与胃癌的关系。结果胃癌组织表达呈阳性的患者例数,多于阴性的患者例数,同时,癌旁正常组织表达呈阳性的患者少于阴性患者,差异具有统计学意义(P<0.05)。结论胃癌患者PTEN基因和表达异常情况都与癌症组织的启动子区甲基化有较大关系,是患者胃癌发生和发展以及转移的原因之一。

胃癌细胞PTEN基因启动子区甲基化与蛋白表达的关系及意义

目的探讨胃癌细胞中抑癌基因PTEN 5’启动子区CpG岛甲基化状态与其蛋白表达的关系。方法采用甲基化特异性聚合酶链反应(M SP)方法检测不同分化程度的胃癌细胞(HGC-27,M GC-803,BGC-823,SGC-7901)中PTEN基因启动子区域甲基化状态,并通过W estern b lot法检测该4种细胞中PTEN蛋白的表达。结果除SGC-7901外,其他三种胃癌细胞PTEN基因都有不同程度的甲基化,并随着胃癌细胞分化程度的降低,PTEN启动子区甲基化逐渐增强(P<0.01);PTEN蛋白表达逐渐减弱(P<0.01)。PTEN蛋白表达与其启动子区高甲基化之间呈负相关。结论PTEN基因启动子区异常甲基化可能导致该基因失活,使其蛋白表达减少甚至缺失,这可能是导致胃癌发生、发展的重要机制之一。

Relationship between promoter methylation and mRNA expression of PTEN gene and gastric carcinoma

Objective:To probe into the relationships between PTEN gene expression,the promoter methylation and gastric cancer and its clinical pathological specific features.Methods:We analyzed the PTEN gene promoter methylation and mRNA expression status in gastric cancer tissues and its adjacent normal tissues by methylation specific PCR(MSP) and reverse transcription-polymerase chain reaction(RT-PCR) techniques.Results:PTEN promoters in 48.2%(27/56) gastric cancer tissues and 3.6(2/56) adjacent normal tissues were methylated and the PTEN promoter methylation rate in carcinoma tissues was obviously higher(P < 0.05).Of the 2 cases where the adjacent gastric tissues were methylated,the gastric cancer tissues were both methylated.Of the 29 gastric cancers with lymph node metastasis,19 had their PTEN gene promoters methylated and the PTEN gene promoter methylation in cases with lymph node metastasis was obviously higher than that without lymph node metastasis(P < 0.05).RT-PCR result showed that no expression of PTEN mRNA existed in any of the methylated gastric cancer tissues.Conclusion:The expression loss of PTEN gene mRNA in gastric cancers is related to their promoter methylation and might be one of the reasons for the generation,development and metastasis of gastric cancers.