OBJECTIVESTo investigate whether the human PC-3 cell infected with recombinant Ad-PTEN and Ad-p27Kip1 can steadily produce PTEN and p27Kip1 protein and change the biologic behaviors such as cell proliferation, cell cycle and apoptosis. The synergistic effect of PTEN and p27Kip1 on the therapy for prostate cancer has also been investigated.

METHODSWe constructed recombinant adenovirus vector of human tumor suppressor gene PTEN and p27Kip1. The viral titer was examined by plaque assay and the mRNA and protein expressions of PTEN and p27Kip1 in human prostate cancer cell line PC-3 infected with Ad-PTEN and Ad-p27Kip1 were determined by RT-PCR and Western blot respectively. MTT assay was used to determine the effect of PTEN and p27Kip1 on growth and proliferation of PC-3 cell; the change of cell cycle and apoptosis was examined by flow cytometry, and to compare between the combined therapy group and single gene therapy group.

RESULTSThe viral titers of Ad-PTEN and Ad-p27Kip1 were 1.8 x 10(7) pfu/ml and 1.2 x 10(9) pfu/ml respectively. After infected by adenovirus, it had been verified that the mRNA and protein expression of PTEN and p27Kip1 were steady in human PC-3 cell. Ad-PTEN and Ad-p27 Kip1 inhibited the growth and proliferation of PC-3 cells. The progression of cell cycle of PC-3 cell was arrested in G(0)-G(1) phase, meanwhile the apoptosis rate of PC-3 was also affected after Ad-PTEN or/and Ad-p27 Kip1 infected. There was significant difference between combined therapy group and single gene therapy group.

CONCLUSIONThe recombinant Ad-PTEN and Ad-p27Kip1 vector were constructed successfully and the expression of specific PTEN and p27Kip1 was high, steadily in PC-3 cell line. These results suggested that combination of PTEN with p27Kip1 has an application value in treatment of prostate cancer in future.