Standard therapies for prostate cancer including radiation, prostatectomy, and hormone ablation have significant toxicities and recurrence risk. Replication-competent oncolytic herpes simplex virus (oHSV) vectors are a powerful antitumor therapy that can exert at least two effects: direct cytocidal activity that selectively kills cancer cells and induction of antitumor immunity. Cells were grown in six-well plates and infected at 90–95% confluence with either bPΔ6-hPAP, bPΔ6-mPAP or bPΔ6-empty viruses at a multiplicity of infection (MOI) of 2. The prognosis for those patients who develop castration resistant disease is poor.24 Despite recent advances in medical therapies,25, 26, 27, 28 men with prostate cancer will ultimately develop treatment-refractory, incurable disease. Mice bearing human prostate LNCaP tumors, treated with a single intravenous injection of 5 × 107 plaque-forming units (pfu) of AU27 virus exhibited a >85% reduction in tumor size at day 28 after viral injection. In addition the combined-therapy group had a mean survival of 22 days versus 16.6 days for single therapy and 13.8 days for nontreated controls. The choice of vector is a crucial aspect of any gene therapy strategy, and will have a significant influence on treatment success.
Next, we evaluated the killing activity of this recombinant adenovirus.