| Background: Gastric carcinoma is one of the most common malignant diseases and isthe second most common cause of cancer related death in China and in the worldDuring recent years, a lot of researchers have proved that the occurrence, developmentand prognosis in the gastric carcinoma result from the alteration of many genes.Therefore, studies on the changes in related genes and protein of gastric cancer can notonly help to understand its pathogenesis, but also help to find molecular markers withclinical significance in the diagnosis and prognosis of gastric cancer. Caudal-relatedhomeobox2(CDX2), which is a member of the caudal-related homeobox gene family,plays an important role in mammalian early intestinal development and the maintenanceof intestinal epithelia through its regulation of intestine-specific gene transcription.Normally, CDX2is expressed in small intestinal and colonic epithelia, but not in thestomach and esophagus. However, several studies showed that CDX2expression isobserved in intestinal metaplasia of chronic atrophic gastritis (CAG), Barrett Esophagusand part of gastric cancers, suggesting that CDX2may have an important role inintestinal metaplastic differentiation and is also involved in gastric carcinogenesis.Objective: To construct a eukaryotic expression vector with human caudal-relatedhomeobox2(CDX2) gene and transfect pEGFP-C1-CDX2eukaryotic expressionplasmid in BGC-823cells. To investigate the effects of over-expression of CDX2on thebiological behavior in gastric cancer cells.Methods: The pcDNA4/TO/Myc-HisA-CDX2was given by Dr. Toshihiro Uesaka.. ThepEGFP-C1-CDX2eukaryotic expression plasmid was constructed by DNA recombinantmethod．pEGFP-C1-CDX2was transfected into BGC-823cells with tffection reagent. Lipofectamine．G418resistant colonies were selected by adding G418to the medium．CDX2mRNA and protein expression were assessed by RT-PCR and Western blot．TheMTT and cell scratch test method were used to study the proliferation and migration ofBGC-823cells, BGC-823/EV cells and BGC-823/CDX2cells. The cell apoptosis wereassessed by flow cytometry. Electronic microscopy was used to observe the changingpatterns of cells.Results:(1) The eukaryotic expression vector pEGFP-C1-CDX2was successfullyconstructed.(2) The gastric cancer cells BGC-823that stable expressed CDX2gene wassuccessfully established, which was named as the BGC-823/CDX2cells.(3) Theexpression of CDX2mRNA and protein in BGC-823/CDX2cells were up-regulatedsignificantly compared with the BGC-823cells and BGC-823/EV cells.(4) MTTshowed that the proliferation of BGC-823/CDX2cells was inhibited compared with theBGC-823cells and BGC-823/EV cells within72hours after transfection cells.(5) Thecell scratch test showed that the migration ability of BGC-823/CDX2cells decreasedcompared with BGC-823cells and BGC-823/EV cells.(6) The flow cytometry resultsrevealed no significant differences in apoptosis rate in BGC-823/CDX2cells comparedwith BGC-823/EV cells and BGC-823cells.(7) Electron microscopy showed theBGC-823/CDX2group had more cell death compared with the BGC-823cells. Earlyapoptosis phenomenon such as the shrinking of nuclear membrane and chromatincondenses could be found in part of the cells.Conclusions: A gastric cancer cell line with stable over-expression of CDX2wasestablished successfully，which was named BGC-823/CDX2cells. CDX2gene couldinhibit the proliferation and migration of BGC-823cells in vitro. These resultsdemonstrate that CDX2gene may play an inhibitory role in gastric carcinoma. |
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