Fig. 2

Ectopic expression of IL-13Rα2 promotes glioma invasion. a In vitro migratory capacity of control and IL-13Rα2-RNAi treated U87MG cells was determined. Percent of migrated cells was normalized to CTRL-RNAi. b U87MG cells were transfected with non-specific siRNA (CTRL-RNAi) or IL-13Rα2 specific siRNA (IL-13Rα2-RNAi). Cell proliferation was subsequently determined, and the percent of proliferation was normalized to CTRL-RNAi day 1. c In vitro migratory capacity of control and IL-13Rα2-RNAi treated U87MG cells, stimulated with 1 µg ml⁻¹ YKL40 or 20 ng ml⁻¹ IL-13 for 18 h, was determined using wound-healing migration assay. All data are represented as mean ± SEM. Unpaired t-test *p < 0.05; ***p < 0.001; NS not significant. d Immunoblotting experiment showing upregulation of MMP-2, and vimentin in Gli36.IL-13Rα2 cells. Densitometry quantification was done for the indicated proteins by normalizing to pan-actin as the internal loading control. Ratios were indicated below each blot. e Mice were implanted with either Gli36-GFP or Gli36.IL-13Rα2-GFP cells intracranially. Tumors were collected from representative mice implanted with Gli36.IL-13Rα2-GFP showed the invasive phenotype (left panel) when compared to the contralateral normal brain parenchyma (right panel) by haematoxylin and eosin (H&E) staining. Red arrows indicated glioma tumor at the invasive front f Representative images of mouse brain transplanted with Gli36- GFP cells and Gli36-IL-13Rα2-GFP, counterstained with DAPI (blue). The top panel shows the contralateral hemisphere; bottom panel shows tumor-bearing hemisphere of the mouse brain (N, normal; T, tumor). Scale bar, 50 μm. g Immunofluorescence red staining of MMP-2, vimentin or isotypic control in mice bearing either Gli36.IL-13Rα2-GFP or Gli36-GFP. Scale bar, 50 μm. h Kaplan−Meier survival curves of mice bearing Gli36 and Gli36.IL-13Rα2 tumors. NS not significant