中文摘要：

目的探讨转化生长因子β1（TGF-β1）和EB病毒（EBV）潜伏期膜蛋白1（LMP1）在EBV相关胃癌发生中的作用及其机制。方法设计合成靶向LMP1的siRNA649转染EBV阳性胃癌细胞系GT38，并与TGF-β1联合作用，RT-PCR检测LMP1沉默和TGF-131作用对LMP1介导的信号转导通路相关因子转录表达的影响。结果与细胞对照和脂质体对照比较，siRNA649、siRNA649＋TGF81分别作用GT38细胞系后，基质金属蛋白酶9（MMP9）、生存素（Survivin）和细胞黏附分子1（ICAM-1）表达降低，而细胞周期依赖性激酶4（CDK4）表达升高，差异均有显著性（F=10．48-26．23，P〈0．05）；siRNA649＋TGF-β1联合作用后表皮生长因子受体（EGFR）表达水平显著高于对照组（F=9．47，P〈0．05），而siRNA649组与对照组比较差异无显著性（P〉0．05）。TGF-β1作用EBV阳性细胞系（GT38和SNU719）和EBV阴性细胞系（SGC7901和HGC-27），与对照组相比GT38细胞中ICAM-1表达显著降低，差异有显著性（F=30．36，P〈0．05），其他细胞中ICAM-1的表达差异无显著性（P〉0．05）；4种细胞系TGF-β1作用前后MMP9、Survivin、CDK4和EGFRtuRNA转录表达差异均无显著意义（P〉0．05）。结论LMP1可以调控MMP9、Survivin和CDK4表达，LMP1与TGF-β1相互作用可调控ICAM-1和EGFR的转录表达。

英文摘要：

Objective To explore the mechanism of transforming growth factor-β1 （TGF-β1） and Epstein Barr virus （EBV） latent membrane proteinl （LMP1） in EBV-associated gastric carcinoma （EBVaGC）. Methods The siRNA targeted to LMP1 （siRNA649） was designed and synthesized. The EBV-positive gastric carcinoma cell line （GT38） was treated with si RNA649 and TGF-β1. RT-PCR was used to detect the expression of LMPl-mediated signal pathway transforming factors. Re- sults After respective treatment with siRNA649 and siRNA649＋TGF-β1, the expression of MMP9, Survivin and ICAM-1 de creased in EBV positive cell line （GT38） and CDK4 increased, the difference was significant （F = 10.48-26.23,P〈0.05） ; After combined action of siRNA649q TGF-β1, the expression of EGFR was higher than that in the normal control （F=9.47 ,P〈0.05）, while the difference between siRNA649 and normal control was not significant. Compared with the normal control, the expression of ICAM-1 decreased in GT38 （F=30.36,P〈0.05）, but not in other cell lines after TGF-β1 treatment in EBV positive cell lines （GT38 and SNU719） and EBV negative cell lines （SGC7901and HGC-27） （P）0.05）. In the four cell lines, the mRNA expression of MMPg, Survivin, CDK4 and EGFR was not different between before and after TGF-β1 treatment （P〉0.05）. Conclusion LMP1 can regulate the expressions of MMPg, Survivin and CDK4. The interaction of ICAM-1 and EGFR can regulate the tran- scription expression of LMP1 and TGF-β1.