Effect Of CDX2Overexpression On Gene Expression Profile Of Gastric Carcinoma Cell Line BGC-823

Objective To research the effects of CDX2gene over-expression on gene expressionprofile of gastric carcinoma cell line BGC-823by cDNA microarrays. Methods Theplasmid pEGFP-C1-CDX2and the control vector pEGFP-C1were transfected intoBGC-823cells in vitro by using the lipofectamin transfection reagent respectively. Thestably transfected cells were obtained by using G418to screen the resistant clones. Theexpression levels of CDX2mRNA were detected by RT-PCR and Western blotting.Different gene expression profiles between the two groups were analyzed byaffymetrix human genome U1132.0arrays, and differentially expressed genes wereobtained by Ratio≥2.0or Ratio≤0.5. Part of the results of cDNA microarray wasconfirmed by real-time PCR. The expression levels of differentially expressed genes inhuman gastric cancer cell lines MGC-803, BGC-823, SGC-7901, normal gastricmucosa cell line GES-1,10cases of gastric cancer tissues and the adjacent tissues weredetected by RT-PCR. Results RT-PCR and Western blotting indicated that theexpression of CDX2increased remarkably in the transfection group as compared to theblank control and the empty vector groups.599differentially expressed genes ingastric cancer cells transfected with CDX2gene were screened using cDNAmicroarray technology.275genes were up-regulated and324genes weredown-regulated in BGC-823/CDX2cells. These genes were involved in cellproliferation, differentiation, apoptosis, signal transduction, protease activity, celladhesion and so on. Six differentially expressed genes (DKK3, FOXP1, TWIST1,GATA6, RUNX3and BMP2) were selected for real-time PCR and the results were inaccordance with that of cDNA microarrays. The results of RT-PCR showed that theexpression levels of DKK3, FOXP1, TWIST1, GATA6, RUNX3and BMP2in human gastric cancer cell lines MGC-803, BGC-823, SGC-7901and in normal gastric mucosacell line GES-1were significantly different (P<0.05). The expression levels of DKK3,FOXP1, TWIST1, GATA6, RUNX3and BMP2in gastric cancer tissues and theadjacent tissues were also significantly different (P<0.05). Conclusion Thedifferentially expressed genes in gastric cancer cells transfected with CDX2gene werescreened successfully using cDNA microarray technology. The altered genes may beuseful to clarify the mechanism of CDX2in gastric cancer.