中文摘要：

瞄准：调查在 vitro 并且在 vivo 在人的胃的癌症 MGC-803 房间上 Cdx2 指向的小干扰 RNA (siRNA ) 的效果。方法：recombinant pSilencer 4.1-Cdx2 siRNA plasmids 被构造并且 transfected 进在 vitro 的胃的癌症 MGC-803 房间。稳定的 transfectants 被选择。人的胃的癌症 MGC-803 细胞的生长，增长，细胞周期， apoptosis ，移植和侵略上的 Cdx2 siRNA 的效果被评估并且磷酸酶和 tensin 相当或相同的事物( PTEN )的表示， caspase-9 和 caspase-3 被反向的抄写聚合酶链反应( RT-PCR )和西方的弄污分析在 vitro 观察。我们也在 vivo 在裸体老鼠在 MGC-803 房间的生长上调查了 Cdx2 siRNA 的效果。结果：Cdx2 siRNA 导致了由 RT-PCR 和西方的弄污分析决定了的内长的 Cdx2 mRNA 和蛋白质表示的抑制。Cdx2 siRNA 显著地禁止了细胞生长和增长，堵住了入口进细胞周期的 S 阶段，导致了细胞 apoptosis，并且减少了 MGC-803 细胞的活动性和侵略。Cdx2 siRNA 也增加了 PTEN 表示，并且在 vitro 在 MGC-803 房间激活 caspase-9 和 caspase-3。另外， Cdx2 指向的 siRNA 禁止了 MGC-803 房间的生长并且在裸体老鼠肿瘤模特儿在 vivo 支持了肿瘤房间 apoptosis。结论：Cdx2 涉及调整人的胃的癌症房间 MGC-803 的前进。Cdx2 表示的操作可以是为胃的癌症的潜在的治疗学的策略。

英文摘要：

AIM：To investigate the effects of small interference RNA（siRNA） targeting of Cdx2 on human gastric cancer MGC-803 cells in vitro and in vivo.METHODS：The recombinant pSilencer 4.1-Cdx2 siRNA plasmids were constructed and transfected into gastric cancer MGC-803 cells in vitro.The stable transfectants were selected.The effects of Cdx2 siRNA on growth,proliferation,cell cycle,apoptosis,migration and invasiveness of human gastric cancer MGC-803 cells were evaluated and the expression of phosphatase and tensin homolog（PTEN）,caspase-9 and caspase-3 was observed in vitro by reverse transcription polymerase chain reaction（RT-PCR） and Western blotting analysis.We also investigated the effect of Cdx2 siRNA on growth of MGC-803 cells in nude mice in vivo.RESULTS：Cdx2 siRNA led to inhibition of endogenous Cdx2 mRNA and protein expression as determined by RT-PCR and Western blotting analysis.Cdx2 siRNA significantly inhibited cell growth and proliferation,blocked entry into the S-phase of the cell cycle,induced cell apoptosis,and reduced the motility and invasion of MGC-803 cells.Cdx2 siRNA also increased PTEN expression,and activated caspase-9 and caspase-3 in MGC-803 cells in vitro.In addition,siRNA targeting of Cdx2 inhibited the growth of MGC-803 cells and promoted tumor cell apoptosis in vivo in nude mice tumor models.CONCLUSION：Cdx2 was involved in regulating progression of human gastric cancer cells MGC-803.Manipulation of Cdx2 expression may be a potential therapeutic strategy for gastric cancer.