Therapeutic effects of gelatin matrix-embedded IL-12 gene-modified macrophages in a mouse model of residual prostate cancer.

We evaluated the potential use of intraoperative gelatin matrix hemostatic sealant (GMHS; FloSeal; Baxter Healthcare) embedded with macrophages (Mphi) transduced with murine interleukin (IL)-12 recombinant adenoviral vector (G/Mphi/AdmIL-12) for prevention of recurrence of prostate cancer following radical prostatectomy. Application of G/Mphi/AdmIL-12 resulted in significant suppression of tumor growth and spontaneous lung metastases, a statistically significant survival advantage of the G/Mphi/AdmIL-12-treated animals, more efficient trafficking of Mphi to lymph nodes draining from the prostate and generation of systemic natural killer cell activity and tumor-specific cytolytic T lymphocyte responses compared to the controls in a preclinical mouse model of residual prostate cancer. Our data recommend this treatment as a novel adjuvant for prevention of local recurrence of prostate cancer following radical prostatectomy.