Figure 4.

Analysis of NIS protein expression in U87 tumors ex vivo

Immunohistochemical staining of NIS protein in GBM xenografts embedded in paraffin revealed a higher NIS expression (red) in mice treated with targeted polyplexes (monoDBCO-PEG₂₄-GE11/NIS [A] and bisDBCO-PEG₂₄-GE11/NIS [F]) 48 h before sacrifice compared with the 24h time point (B). No positive NIS staining in tumors of mice that received control polyplexes (C, D, G, and H) or untreated (E) mice was observed. Liver (I), lung (J), kidney (K), and spleen (L) did not show any NIS expression. One representative image with 20× original magnification is shown for each group (scale bar: 100 μm). A 40× original magnification was chosen for the close up (scale bar: 50 μm).