Figure 4.
Retardation of HepG2 tumor growth in mice dosed IV with 1 × 105 copies of VVTK-RR-/FCU1 and dosed with 5-Fluorocytosine (5-FC). A dose of 1 × 105 vaccinia virus (VV), expressing an enzyme for the conversion of 5-FC to 5-fluorouracil (5-FU), was injected IV with or without the application of cups and ultrasound (US). After 7 days, 5-FC dosing commenced with daily s.c. injection of 100 µl of 12.5 mg/ml (black arrow). Tumor size was assessed by caliper measurements (a). N = 10, standard error of the mean shown, (*P < 0.05, by analysis of variance (ANOVA) with all group comparisons and Bonferroni post-test). Black arrow denotes commencement of daily dosing with 100 µl of 12.5 mg/ml 5-FC. (b) Representative mice from the study described in 4a were photographed 9 days after dosing with VV. Dramatic differences in the size and stiffness of the tumors were observed.