Fig. 6

Multicellular tumor spheroid (MCTS) models showed increased targeted gene transfer by RGD4C.AAVP in combination with ECM depletion. a Concentration gradient curves of ECM degrading collagenase or hyaluronidase enzymes in 9L MCTS generated by quantification of post-transduction day 3 Luc gene expression through Steady-Glo® assay. RGD4C.AAVP/Luc was applied to cells that underwent collagenase or hyaluronidase treatments. b Quantification of RGD4C.AAVP-mediated luciferase expression in 9L MCTS following treatment with combination of optimal concentrations of collagenase (0.2 mg/ml) or hyaluronidase (1 mg/ml). RGD4C.AAVP/Luc alone, without enzymes, was included as control treatment. All experiments used triplicates for samples and were conducted at least twice. Luciferase expression results are shown as relative luminescence units/1 μg protein and presented as mean ± s.e.m.. One way ANOVA with Tukey’s post-test was used for the concentration curve whereas unpaired student’s t-test made comparisons between control and combination treatment, *, p < 0.05, **, p < 0.01, ***, p < 0.001. Experiments were repeated twice and individual conditions were repeated in triplicates