Figure 6.

Ex vivo analysis of brain tumors after IL-6 promoter-induced MSC-mediated NIS gene therapy

At the end of the therapy study, frozen brain tissue sections derived from mice that were treated with IL-6-NIS-MSCs + ¹³¹I (A), IL-6-NIS-MSCs + NaCl (B), and NaCl only (C) were subjected to Ki67 (proliferation index; green) and CD31 (blood vessels; red) immunofluorescence staining. Nuclei were counterstained with Hoechst (blue). A representative picture is shown in each at ×40 magnification (scale bar, 40 μm). Quantification of the proliferation index (D) and blood vessel density of IL-6-NIS-MSCs + ¹³¹I in comparison with both control groups (E). Results are expressed as mean ± SEM (two-tailed Student’s t test ∗p < 0.05; ∗∗p < 0.01).