OBJECTIVETo evaluate the antitumor efficacy of proliferating cell nuclear antigen antisense oligonucleotide (PCNA-ASO) in combination with recombinant adenovirus p53 (Ad-p53) against bladder cancer EJ and BIU-87 cells in vitro and in vivo.

METHODSCells were transfected with Ad-p53 (100 MOI), and PCNA-ASO (1.6 micro mol/L) was then introduced into the cells using a cationic lipid (lipofectamine, 20 micro l/ml). In vitro and in vivo antitumor effects of combining PCNA-ASO with Ad-p53 were measured using the MTT assay, flow cytometry, clone formation, and a nude mice model.

RESULTSThe combination of PCNA-ASO and Ad-p53 inhibited cell viability in both the EJ (89.3%) and BIU-87 (78.6%) cell lines. The ability of the cells to form foci was also reduced by 74.8% in EJ cells and by 67.5% in BIU-87 cells (P < 0.01). A significant decrease of cells in the S phase (11.4% in EJ cells, 14.6% in BIU-87 cells) and a significant increase of cells in G1 phase (62.2% in EJ, 56.8% in BIU-87) were noted. The mean tumor volume after 7 days of treatment with PCNA-ASO or Ad-p53 in combination decreased to 47.6% or 36.4% of the initial tumor size in the two cell lines respectively.

CONCLUSIONThese results indicate that combined PCNA-ASO and Ad-p53 in the treatment of bladder cancer with mutant p53 has important therapeutic potential, significantly suppressing the growth of human bladder cancer both in vitro and in vivo.