Effects of silencing B7-H4 expression by small interference RNA on proliferation,invasion and migration of human lung adenocarcinoma A549 cells

Objective:To investigate the effects of silencing B7-H4 expression by small interference RNA(siRNA) on proliferation,invasion and migration of human lung adenocarcinoma A549 cells.Methods: Chemically synthesized siRNA targeting B7-H4(B7-H4-siRNA) was transfected into A549 cells.The proliferation of A549 cells was determined by MTT assay,the cell cycle was detected by flow cytometry,the levels of B7-H4 and Cyclin D1 were verified by Western blotting,and the invasion and migration ability was detected by Transwell assay.Results: B7-H4-siRNA was successfully transfected into A549 cells.Western blotting results showed that B7-H4-siRNA transfection inhibited the expressions of B7-H4 and Cyclin D1 in A549 cells.In the B7-H4-siRNA group,the proliferation of A549 cells was significantly down-regulated,the doubling time was longer than that in the untransfected group,the Ctrl-siRNA group and the empty vector group([33.78±0.26] h vs [28.69±0.18],[27.32±0.13],[26.93±0.19] h,P0.05),and the cell cycles were arrested in G1 phase.The invasion of A549 cells in the B7-H4-siRNA group was inhibited significantly as compared with the untransfected group([89.80±0.99] vs [186.20±1.33],P0.05),and the migration of A549 cells in the B7-H4-siRNA group was suppressed significantly as compared with the untransfected group,the Ctrl-siRNA group and the empty vector group([60.20±0.37] vs [102.57±0.52],[100.72±0.31],[98.65±0.21],P0.05).Conclusion: B7-H4-siRNA can silence B7-H4 expression in A549 cells,and inhibit the proliferation,invasion and migration of A549 cells effectively.B7-H4 can be regarded as a candidate gene for lung cancer gene therapy.