中文摘要：

目的：将编码Notch1胞内域（NICD）转染人舌麟状细胞癌（舌麟癌）Tca8113细胞，探讨Notch1在Tca8113细胞中的作用及其对表皮生长因子受体（EGFR）表达的影响。方法：采用脂质体法将编码NICD的pRAMIC-IRES2-EGFP目的质粒和pIRES2-EGFP对照质粒分别转染人舌麟癌Tca8113细胞，实验分为目的质粒pRAMIC-IRES2-EGFP转染组、对照质粒pIRES2-EGFP转染组和非转染组。采用RT-PCR法、Westernblotting法和免疫细胞化学法观察细胞中Notch1mRNA及蛋白和EGFRmRNA及蛋白表达水平，MTT法检测Tca8113细胞的增殖活性并计算细胞存活率。结果：转染后，与非转染组和对照质粒plRES2-EGFP转染组比较，pRAMIC-IRES2-EGFP目的质粒转染组Notch1mRNA和蛋白表达水平明显升高（P〈0．05），而EGFRmRNA和蛋白表达水平明显降低（P〈O．05），细胞存活率明显降低（P〈0．05）。与非转染组比较，对照质粒pIRES2-EGFR转染组Notch1mRNA和蛋白表达水平、EGFRmRNA和蛋白表达水平及细胞存活率差异无统计学意义（P〉0．05）。结论：Notch1对舌麟癌Tca8113细胞增殖的影响可能与EGFR的表达下调有关。

英文摘要：

Objective： To transfect the tongue squamous cell carcinoma Tea8113 cells with NICD, and to investigate the effects of Notch 1 on Tca8113 cells and the expression of epidermal growth factor receptor （EGFR） in tongue squamous cell carcinoma. Methods： The Notch plasmid pRAMIC-IRES2-EGFP encoding exogenous and control plasmid plRES2-EGFP were transiently transfected into the Tea8113 cells by LipofectamineTM 2000. In the experiment, target plasmid pRAMIC-IRES2-EGFP transfection group, control plasmid plRES2-EGFP transfection group and non-transfection group were set up. RT-PCR, Western blotting and immunocytochemical method were used to observe the mRNA and protein expression levels of Notch 1 and EGFR. The proliferation activities of Tea8113 cells were detected by MTT assay, and the survival rates were calculated. Results： Compared with non- transfection group and control plasmid plRES2-EGFP transfection group, the mRNA and protein expression levels of Notch 1 in Tca8113 cells in pRAMIC-IRES2-EGFP group was significantly increased （P〈0.05）, the mRNA and protein expression levels of EGFR in TcaSll3 ceils were significantly decreased （P〈0.05）, and the proliferation rate of Tca8113 cells was significantly decreased （P〈0.05） after transfection. There were no significant differences in the expression levels of Notch 1 and EGFR mRNA and protein and the proliferation rates in Tca8113 cells between non-transfection group and pRAMIC-IRES2-EGFP group （P〉0.05）. Oonclusion： The effect of Notch 1 on the proliferation of Tca8113 cells may be related to down-ragulatoin of expression level of EGFR.