Figure 8.

In vivo evaluation of heparin/protamine regulation on TAT-Gel cell transduction using LS174T s.c. xenograft tumor mouse model. (A) Tumor growth profiles. When the average tumor size reached 100 mm³ (at day 16; 16 days after tumor implantation at day 0), mice were divided into 5 groups (N=5), and treated twice with PBS (circle), TAT-Gel (triangle), TAT-Gel/Hep (square), “TATGel/Hep+Pro” (diamond) or protamine (a.k.a. Pro; reverse triangle) by intra-tumor injection at day 16 and 22. TAT-Gel/Hep complex was prepared by mixing TATGel with 3-fold molar excess of heparin and incubation at 4°C for 30 min. For “TAT-Gel/Hep+Pro” treatment, administration of TAT-Gel/Hep was followed by injection of protamine (3-fold molar excess against heparin) to the tumor with 5 min interval. Tumor sizes were measured daily since tumor implantation (at day 0). (B) Average tumor sizes at day 38 when the average tumor volume of PBS-treated mice reached 2000 mm³. Statistical significant differences in the tumor sizes among the groups were compared by 1-way ANOVA with Tukey's multiple comparison test as the post hoc test. *** P < 0.0001. (TAT-Gel: recombinant TAT-gelonin fusion protein).