Effects Of Silencing B7-H4Experssion By Small Interference RNA On Proliferation,Apoptosis,Invasion And Migration Of Human Lung Adenocarcinoma A549Cells

Objective：To investigate the effects of silencing B7-H4expressionby small interference RNA(siRNA) on proliferation,apoptosis,invasion andmigration of human lung adenocarcinoma A549cells.Methods:Chemically synthesized siRNA targeting B7-H4(B7-H4-siRNA)was transfected into A549cells with human lung adenocarcinoma byEntransterTM-R. The proliferation and invasion of of A549cells wasdetermined by methyl thiazol tetrazolium(MTT)assay,the cell cycle wasdetected by Flow cytometry,the levels of B7-H4and CyclinD1wereverified by Western blotting,And the invasion and migration ability wasdetected by Transwell assay.Results:B7-H4-siRNA was successfully transfected into A549cells.Western blotting results showed that B7-H4-siRNA transfectioninhibited the expression of B7-H4and CyclinD1in A549cells.In theB7-H4-siRNA group,the proliferation and apoptosis of A549cells was significantly down-regulated,the doubling time was longer than that in theuntrensfected group,the Ctrl-siRNA group and the empty vectorgroup([33.78±0.26]vs[28.69±0.18],[27.32±0.13],[26.93±0.19]h,P<0.05),and the cells cycles were arrested in G1phase.The invasion of A549cells inthe B7-H4-siRNA group was inhibited significantly as compared with theuntrensfected group([89.80±0.99] vs [186.20±1.33],P <0.05),and themigration of A549cells in the B7-H4-siRNA group was suppressedsignificantly as compared with the untrensfected group,the Ctrl-siRNAgroup and the empty vector group([60.20±0.37] vs [102.57±0.52],[100.72±0.31],[98.65±0.21],P <0.05).Conclusion:B7-H4-siRNA can silence B7-H4expression in A549cells,and inhibit the proliferation,apoptosis,invasion and migration of A549cells effectively.B7-H4can be regarded as a candidate gene for lung cancergene therapy.