Figure 3

Tumor growth inhibition assay. Two weeks after subcutaneous inoculation of SKOV3 cells in BALB/c nude mice, complexes of pPB/TK, pPB, pORF-HSVtk with PEI were injected directly into the tumor three times (days 1, 4 and 7). GCV solution was administered by daily intraperitoneal injection beginning on the day after the first complex injections. Tumor volumes were monitored over time. Mice were sacrificed 3 weeks after transfection in vivo. Errors bar represent the standard error of the mean.* p < 0.01, comparing the PB/TK group with the control group at day 21.