Inhibition of human bladder cancer growth by a suicide gene delivered by JC polyomavirus virus-like particles in a mouse model

Purpose: Bladder cancer is one of the most common cancers of the urinary tract. The poor 5-year survival rate of invasive bladder cancer represents a challenge for bladder cancer treatment. Previous studies demonstrated that human urothelial carcinoma is susceptible to infection by JC polyomavirus. We used JC polyomavirus virus-like particles to deliver genes into human urothelial carcinoma cells for possible therapeutic investigation.

Materials and methods: Reporter plasmids (pEGFP-N3) for expressing green fluorescent protein, LacZ expression plasmids bearing cytomegalovirus or Muc1 promoter and a functional plasmid (pUMVC1-tk) for expressing thymidine kinase were packaged into JC polyomavirus virus-like particles. Plasmid DNAs were transduced via the JC polyomavirus virus-like particles into human urothelial carcinoma cells in vitro and into xenografted human bladder tumor nodules in vivo.

Results: pEGFP-N3 DNA was delivered and green fluorescent protein was expressed in human urothelial carcinoma cells in vitro and in the tumor nodules of mice in vivo. The thymidine kinase transgene also functioned in vitro and in vivo after JC polyomavirus virus-like particle transduction. The thymidine kinase gene transduced urothelial carcinoma nodules were drastically reduced in the presence of acyclovir. In addition, we noted selective Muc1-LacZ expression in human urothelial carcinoma cells transduced by JC polyomavirus virus-like particles.

Conclusions: These findings provide a possible future approach to human urothelial carcinoma gene therapy using JC polyomavirus virus-like particles.