中文摘要：

目的探讨Eph A2基因表达沉默对胃癌AGS细胞上皮-间质转化的影响机制。方法将对数生长期的胃癌AGS细胞接种于6孔板并分为Eph A2 si RNA组、阴性对照组和空白对照组。采用Eph A2 si RNA转染胃癌AGS细胞,采用实时定量聚合酶链反应检测转染细胞Eph A2的表达,采用相差显微镜观察细胞形态的变化,采用Transwell实验检测转染细胞的侵袭能力,应用蛋白质印迹法检测转染细胞E-cadherin和vimentin蛋白的表达。结果 Eph A2 si RNA组的Eph A2 m RNA相对表达量（0.343±0.035）明显低于阴性对照组（0.950±0.036）和空白对照组（0.997±0.065）,差异均有统计学意义（P〈0.05）;Eph A2 si RNA组胃癌AGS细胞呈上皮细胞样,阴性对照组和空白对照组细胞呈间质样细胞;Eph A2si RNA组的侵袭细胞数[（29.1±2.6）个]明显少于阴性对照组[（52.2±2.6）个]和空白对照组[（56.2±4.0）个],差异均有统计学意义（P〈0.05）;Eph A2 si RNA组E-cadherin蛋白的表达量较阴性对照组和空白对照的E-cadherin蛋白的表达量明显上调,而vimentin蛋白的表达量明显下调,差异均有统计学意义（P〈0.05）。结论沉默AGS细胞Eph A2的表达能够抑制胃癌细胞由上皮样细胞向间质样细胞转化,降低AGS细胞的侵袭力,上调上皮性标志物E-cadherin的表达,下调间质性标志物vimentin的表达。

英文摘要：

Objective To study the effect of Eph A2 gene expression silencing on epithelial mesenchymal transition of gastric cancer AGS cells and its mechanism. Methods The gastric cancer AGS cells at logarithmic growth phase were inoculated at the 6-well plate and divided into the Eph A2 si RNA group,negative control group and blank control group. Eph A2 si RNA was adopted to transfected to gastric cancer AGS cells. The Eph A2 expression was detected by real time quantitative PCR. The cell morphology was observed by phase contrast microscope. The invasive ability of transfected cells was determined by Transwell in-vasion assay. The expression of E-cadherin and vimentin protein was detected by Western blotting. Results The Eph A2 m RNA relative expression amount in the Eph A2 si RNA group was 0.343±0.035,which was lower than 0.950±0.036 in the negative control group and 0.997±0.065 in the blank control group,the differences were statistically significant（P〈0.05）;the gastric cancer AGS cells in the Eph A2 si RNA group presented as the epithelioid cell,the cells in the negative and blank control groups showed the mesenchymal-like cells; the invasive cells number in the Eph A2 si RNA group were 29.1 ±2.6,which was significantly less than52.2±2.6 in the negative group and 56.2±4.0 in the blank control group,the differences were statistically significant（P〈0.05）;the E-cadherin protein expression amount in the Eph A2 si RNA group was significantly up-regulated compared with the negative group and blank control group,while the vimentin protein expression amount was significantly down-regulated,the differences were sta tistically significant（P〈0.05）. Conclusion The Eph A2 expression of silencing AGS cells can inhibit the transition from epithelioid cells to mesenchymal like cells,reduces the invasive ability of AGS cells,up-regulates the expression of epithelial marker E-cadherin and down-regulates the expression of mesenchymal marker vimentin.