Abstract: Objective To construct a recombinant lentiviral vector that co-express green fluorescent protein (GFP) and FoxM1
shRNA and establish a prostate cancer cell line with stable FoxM1 down-regulation. Methods Three interfering sequences
targeting FoxM1 were designed and inserted into the lentiviral vector pHBLV-U6-ZsGreen-Puro. After identification by DNA
sequencing, the lentiviral vectors carrying Foxm1 shRNA were packaged in 293 cells. The lentiviral particles were collected to
infect human prostate cancer DU-145 cells, and the transfection efficiency was observed under fluorescence microscope; the
interference efficiency was assessed using real-time PCR. DU-145 cells with stable FoxM1 down-regulation were screened with
puromycin, and the expression level of FoxM1 was detected by Western blotting and the cell growth was observed using MTT
assay. The stably transfected cells were examined for cell apoptosis and cell clone formation capacity with flow cytometry and
colony formation assay. Results DNA sequencing demonstrated successful construction of the 3 FoxM1 shRNA lentivirus
vectors. Real-time PCR showed a high interference efficiency of FoxM1 shRNA1 vector, which resulted in obvious
down-regulation of FoxM1 in DU-145 cells. Western blotting showed that the expression of FoxM1 protein was decreased in
FoxM1 shRNA1 lentivirus-transfected cells, which displayed a suppressed cell proliferation, increased apoptosis rate, and
attenuated clonogenic ability. Conclusion We have successfully established a prostate cancer cell model with stable FoxM1
down-regulation, which shows lowered proliferative and clonogenic activities with increased cell apoptosis.