肝癌细胞中γ-谷氨酰转肽酶基因甲基化研究

目的:研究肝癌细胞中γ-谷氨酰转肽酶(GGT)甲基化的改变。方法:纯化人肝癌及癌旁组织中总GGT及RNA,观察总GGT、膜结合和可溶性GGT的表达,并以逆转录巢式PCR扩增GGT非编码区基因片段,分析M_3位点的甲基化状态。结果:肝癌、癌旁和远癌组总RNA浓度呈明显的梯度升而趋势(P<0.05);癌组织总GGT、膜结合和可溶性GGT均高于癌周又远癌组织(P<0.05);在癌、癌旁及远癌组织中,特定基因片段的扩增检出率分别为100％、85％、75％,M_3位点低甲基化频率分别为75％、55％、50％。结论:肝癌组织中GGT呈异常表达与基因低甲基化状态有关。

Research into Methylation of γ-Glutamyl-transpeptidase (GGT)Gene in the Hepatocellular Carcinoma

Objective:To explore the methylation of GGT gene in the hepatocellular carcinoma. Methods:Total GGT protein and total RNA were purified in human HCC < adjacent paracancerous and distal cancerous tissues. The specific activities of total GGT, membrance-combine GGT and sduble GGT were investigated, GGT gene was amplifed by Using RT-PCR,and methylation status of GGTgene M3site were analysed. Results: An increasing tendency (P<0. 05)of total RNA was found from cancer in distal camerous tissues j specific activities (U/g) of total GGT, membrancecombine GGT and soluble GGT were significantly higher (P<0. 05) in HCC than others gronpi and the frequencies of fragment and hypomethylated M3 site of GGT gene were 100%, 75% in HCC, 85%, 55% in adjacent cancerous, and 75%, 50% in distal cancerous tissues, respectively. Conclusions: The abonormal expression of GGT protein in HCC is related to hy-pomethylation status of GGT gene.