The Effects Of CDX2 Gene Expression And Celluar Biological Behaviors By Short Interfering RNAs In Gastric Cancer Cell Line MGC-803

Objective To investigate the effects of RNA inference(RNAi) targeting CDX2 on biological behaviors of gastric cancer cell line MGC-803.Methods CDX2-siRNA and negative control-siRNA weretransfectedinto gastric cancer cell line MGC-803 by using Lipofectamin^TM2000. 48 hours later, the expression of CDX2 mRNA and protein in gastric cancer cell line MGC-803 was detected by Real-time quantitative PCR and western blotting methods respectively, The proliferative rate of MGC-803 cells was assessed by methyl thiazolyl tetrazolium(MTT) assay and Cloning experiments ; Application of in vitro invasion assay and migration and scratch test experiments were used to detect the CDX2-siRNA on the invasion of gastric cancer cells MGC-803 and the impact of migration; Cell cycle and apoptosis changes were examined by flow cytometry.Results Transfection of gastric cancer cell line MGC-803 with CDX2-siRNA and negative control-siRNA could be mediated by LipofectamineTM2000 effectively. Compared with negative control-siRNA and control group the expression level of CDX2 mRNA and protein measured by Real time quantitative PCR and western blotting decreased by 87.59%,88.91% (P<0.05) and 70.85%,79.3% evidently in gastric cancer cell line MGC-803 transfected with CDX2-siRNA. Compared to negative control-siRNA and control group, the proliferative inhibiting rate of experimental group was75.2% and 85.8% (P<0.05) respectively. More mean DNA content of MGC-803 cells accumulated at G0/G1 phase, the rates of mean G0/G1 content of cells in experimental group, egative control group and non-transfection group were(72.38±1.76)%> (56.67±0.83)% and (59.18±1.24)% respectively, with the difference being significant among them (P<0.05).Apoptosis rate in experimental group (12.53±0.63)%, and with the negative control group (4.46±0.73)% and non-transfection group (5.42±0.32)%, the difference was statistically significant (P <0.05)；At the same time, the invasive power and Migration ability presented a decrease(P <0.05).Conclusions CDX2 gene repression by RNAi can decrease the DNA content in S phase of MGC-803 cell, keep cell division arresting in G0/G1 phase Increased apoptosis and restrained cell proliferation。suppress its invasive power ability to some extent. CDX2 may be a novel therapeutic target for gastric cancer.