Objective      To investigate the effects of S100A11 expression down-regulation on the proliferation

cell cycle and invasion in gastric carcinoma cells.       Methods      Expression of S100A11 protein was examined in 3 gastric carcinoma cell lines (MKN-28

SGC-7901 and MKN-45) and normal gastric mucous epithelial cell GES-1 by Western blotting. S100A11 siRNA and control siRNA were utilized to transfect MKN-45 cells

which were divided into 3 groups

untreated group

control siRNA group and S100A11 siRNA group. Expression of S100A11 protein was investigated after transfection by Western blotting. Subsequently

the changes of cell proliferation

cell cycle and cell invasion were detected by CCK-8 kit

flow cytometry and Boyden chamber assay

respectively. Finally

the expressions of cell cycle- and invasion-related proteins were analyzed by Western blotting.       Results      Positive expression ratio of S100A11 in gastric carcinoma tissues was significantly higher than that in normal gastric mucous epithelial tissues (Chi square=30.110

P=0.000). The levels of S100A11 protein expression in the 3 gastric carcinoma cell lines were significantly higher than that in normal gastric mucous epithelial cells (P0.05). In addition

expression of S100A11 protein in MKN-45 cells was markedly higher than that in MKN-28 and SGC-7901 cells (P0.05). S100A11 siRNA significantly downregulated the level of S100A11 protein in MKN-45 cells

and the downregulation evidently suppressed cell proliferation

altered cell cycle distribution and reduced cell invasion ability. Most notably

the downregulation of S100A11 expression significantly evoked the expression decrease of Cyclin D1

Cdk2 and MMP-2 and increase of E-cadherin.       Conclusion      S100A11 mediates the alterations of biological behaviors of gastric carcinoma cells

which may be tightly associated with the expression changes of Cyclin D1

Cdk2

E-cadherin and MMP-2. Thus

S100A11 may be a potential molecular therapy target of gastric carcinoma.