EVALUATION OF RADIATION EFFECTS AGAINST C6 GLIOMA IN COMBINATION WITHVACCINIA VIRUS-P53 GENE-THERAPY

The primary objective of this study was to evaluate the antitumor effe cts of recombinant vaccinia virus-p53 (rVV-p53) in combination with ra diation therapy against the C6 rat glioma, a p53 deficient tumor that is relatively radioresistant. VV-LIVP, the parental virus (Lister stra in), was used as a control. Localized treatment of subcutaneous C6 tum ors in athymic mice with either rVV-p53 or VV-LIVP together with tumor irradiation resulted in low tumor incidence and significantly slower tumor progression compared to the agents given as single modalities. A ssays of blood and spleen indicated that immune system activation may account, at least partly, for the enhance tumor inhibition seen with c ombined treatment. No overt signs of treatment-related toxicity were n oted.