Abstract: Objective To study the effect of combined cancer-suppressing PTEN and p53 gene on apoptosis of prostate cancer PC-3m cells. Methods Expression vector was constructed for empty plasmid pEGFP-N1, pEGFP-N1-PTEN plasmid, pEGFP-N1-p53 plasmid and pEGFP-N1-PTEN-p53 plasmid, respectively. Their fluorescence expression was observed under microscope after transfection. Expressions of target gene, PTEN and p53 protein were detected by RT-PCR and Western blot, respectively. Cell proliferation inhibition was assayed by MTT assay and cell growth curve was plotted. Effect of PTEN and p53 gene on apoptosis of prostate cancer PC-3m cells was detected by Annexin V-FITC/PI cytometry. Results Fluorescence microscopy showed that PTEN and p53 gene were expressed in PC-3m cells. RT-PCR and Western blot displayed that the expression levels of PTEN and p53 mRNA were significantly higher in combined PTEN and p53 gene-transfected PC-3m cells than in PTEN-, p53-and empty vectortransfected PC-3m cells (P< 0.05). The apoptosis rate of combined PTEN and p53 gene-transfected PC-3m cells was significantly higher than that of PTEN-, p53-and empty vector-transfected PC-3m cells (P< 0.05). Conclusion Transfection of combined PTEN and p53 gene can induce apoptosis of prostate cancer PC-3m cells and can thus be applied in gene therapy for prostate cancer.