Figure 4.

Ex vivo analysis of NIS protein expression

Immunohistochemical staining of NIS protein in GBM xenografts embedded in paraffin showed positive NIS expression (red) in mice treated with targeted NIS polyplexes (A–C). GBM sections of mice treated with Dual/NIS polyplexes revealed a trend toward higher amounts of NIS positive cells (A) compared with mice injected with GE11/NIS (B) or TfRre/NIS polyplexes (C). No positive NIS staining in tumors of mice that received Dual/LUC as control polyplexes (D). Liver (E), spleen (F), kidney (G), and lung (H) sections of a mouse treated with Dual/NIS did not show any NIS expression. One representative image with 20× original magnification is shown for each group (scale bar, 50 μm). A 40× original magnification was chosen for the close-up (scale bar, 20 μm).