Objective        To investigate the effect of small interfering RNA (siRNA)-mediated gene silencing of HER2/neu on the proliferation and apoptosis in bladder cancer cell line BIU-87.       Methods       HER2/neu siRNA was chemically synthesized and transfected into BIU-87 cells mediated by liposome. BIU-87 cells with different treatments were divided into an HER2/neu siRNA group

an empty liposome group

a negative siRNA group and a non-transfection group was the control group. Inhibitory effect of HER2/neu siRNA on BIU-87 cell proliferation was assessed by CCK-8 assay. Cell apoptosis was examined by flow cytometry (FCM). mRNA and protein levels of HER2/neu in BIU-87 cells before and after transfection were detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting.       Results       BIU-87 cells transfected with HER2/neu siRNA showed a significant decrease of cell viability from (82.37±0.90)% to (56.76±1.70)% (P0.05) and cell apoptosis with a rate of (45.60±0.70)%

which was significantly different from that of the control group

empty liposome group and negative HER2/neu siRNA group (P0.05). The siRNA targeting HER2/neu gene significantly reduced mRNA and the protein expressions of HER2/neu in BIU-87 cells (P0.05).       Conclusion       Chemically synthesized siRNA targeting HER2/neu gene

which can effectively inhibit HER2/neu gene expression and subsequently inhibit cell proliferation and induce apoptosis in BIU-87 cells

is a potential target for gene therapy of bladder cancer.