OBJECTIVETo investigate the effects of adenovirus-mediated PTEN and P27 on the invasion of PC-3 in vitro and angiogenesis, along with their synergy in the treatment of prostate cancer.

METHODSRecombinant adenovirus vectors of the human tumor suppressor genes PTEN and P27 were constructed. The replication-incompetent recombinant adenovirus was packaged and propagated in HEK293 cells. The viral titer was examined by plaque assay and the mRNA and protein expressions of PTEN and P27 in human prostate cancer cell line PC-3 infected with Ad-PTEN and Ad-P27 were determined by RT-PCR and Western blot respectively. The invasion of PC-3 cells in vitro was examined by Boyden chamber assay. MTT assay was used to testify the effect of supernatant from PC-3 infected with Ad-PTEN and Ad-P27 on the proliferation of endothelial cells ECV-304 and the CAM test was used to testify the effect of PTEN and P27 on angiogenesis. The difference between the combined therapy group and the single gene therapy group was also examined.

RESULTSThe viral titers of Ad-PTEN and Ad-P27 were 1.8 x 10(7) pfu/ml and 1.2 x 10(9) pfu/ml respectively. Adenovirus infection verified that the mRNA and protein expression of PTEN and P27 were steady in human PC-3 cells. The invasion in vitro of PC-3 cells was significantly inhibited by infection with Ad-PTEN or/and Ad-P27. CAM and MTT assays of ECV-304 confirmed that the supernatant from PC-3 cells infected with Ad-PTEN or/and Ad-P27 could inhibit the angiogenesis effectively. There was a significant difference between the combined therapy group and the single gene therapy group.

CONCLUSIONThe combined gene therapy of Ad-PTEN and Ad-P27 plays a synergistic role in inhibiting the invasiveness of PC-3 cells and angiogenesis.