The Effect Of TGM2 Protein Over-expression On The Proliferation Of GES1 Cells

Objectives: Gastric cancer is one of the most common malignant tumors in our country.In order to understand the pathogenesis of gastric cancer,tissue transglutaminase(Tissue Transglutaminase TGM2)protein were obtained by early study using quantitative proteomics technique from different stages of gastric cancer.The molecular mechanism of TGM2 protein in carcinogenesis of gastric mucosa and its action are cleared for helping to elucidate the mechanism of gastric cancer.Methods: 1.The eukaryotic expression vector of pCDNA3.1-TGM2 was constructed by using PCR technology;2.The eukaryotic expression vector of pCDNA3.1-TGM2 was transfected into immortalized gastric epithelial cell GES1(pCDNA3.1 vector control).The GES1 cell line stably expressing TGM2 protein was establed,through screening by G418 and together after cloning,GES1-TGM2 and GES1-p CDNA3.1cells(vector control).The expression of TGM2 protein was detected by cell immunofluorescence and Western-blot in GES1 cells;3.The cell growth,proliferation,cycle and apoptosis were analysized by cell growth curve,colony formation assay,soft agar colony formation assay and flow cytometry in GES1 cells of TGM2 protein expression.Results:1.The cell growth curve showed that the growth in GES1 cells of TGM2 protein expression was accelerated compared with the control group(P<0.01);2.The plate clone formation experiment results showed that the formation cell clones number was respectively96±15,40±7 and 36±5 in GES1-TGM2 cells,GES1-pCDNA3.1 and GES1 cells.The ability of anchorage dependence growth significantlyincreased in GES1 cells of TGM2 protein expression and the formation cell clones number increased compared with control group and the large volume in GES1-TGM2 cells and GES1-pCDNA3.1 cells(P<0.01);3.The soft agar colony formation assay showed that the formation cell colony number was respectively 128±25,34±12 and 28±6 in GES1-TGM2 cells,GES1-pCDNA3.1 and GES1 cells.The ability of non-anchorage dependence growth significantly increased in GES1 cells of TGM2 protein expression and the formation cell colony number increased compared with control group and the large volume in GES1-TGM2 cells and GES1-pCDNA3.1 cells(P<0.01);4.The flow cytometry showed that the percentage of S phase and G1 phase was respectively 64.2 and 24.5,ane the cell proliferation index was 75.4 in GES1-TGM2 cells.The percentage of S phase and G1 phase was respectively 51.0 and 38.6,and the cell proliferation index was 61.3 in GES1-pCDNA3.1.The percentage of S phase and G1 phase was respectively 49.3 and 40.8,and the cell proliferation index was 59.1 in GES1.The results indicated that the percentage of S phase cells was increased,G1 phase cells was decreased,and the cell proliferation index was increased after in GES1 cells of TGM2 protein expression(P<0.01);In addition,the apoptosis rate was decreased in GES1 cells of TGM2 protein expression(P<0.01).Conclusions: The over expression of TGM2 protein inhibit cell apoptosis and promote cell growth and proliferation of GES1 cells.