Fig. 2

CAFs-derived IL-33 promotes the migration, invasion and EMT of GC cells. a–d The migration and invasion ability of SGC7901 and MKN45 cells were analyzed after culture in medium alone (blank) or treatment with: exogenous IL-33 (300 ng/ml); co-culture with CAFs supplemented with IgG isotype antibody (3 μg/ml) or IL-33 neutralizing antibody (3 μg/ml). Histograms show the average cell number/field (100×; scale bar = 100 μm). e–h The migration and invasion ability of SGC7901 and MKN45 cells was detected after culture in medium alone (blank), co-culture with CAFs transfected with IL-33/siRNA or nc/siRNA. Histograms display the average cell number/field (100×; scale bar = 100 μm). i–l The migration and invasion ability of SGC7901 and MKN45 cells was analyzed after culture in medium alone (blank) or stimulation with exogenous IL-33 (300 ng/ml) plus IgG isotype antibody or ST2L neutralizing antibody (3 μg/ml); co-culture with CAFs in the presence of IgG isotype antibody (3 μg/ml) or ST2L neutralizing antibody (3 μg/ml). Histograms show the average cell number/field. (100×; scale bar = 100 μm). m, n QRT-PCR of the genes for EMT in SGC7901 and MKN45 cells after culture in medium alone (blank); or activation with exogenous IL-33 (300 ng/ml); co-culture with CAFs in the presence of IgG isotype antibody (3 μg/ml) or IL-33 neutralizing antibody (3 μg/ml). o–r Western blot of EMT markers in SGC7901 and MKN45 cells cultured in medium alone (blank); or stimulated with exogenous IL-33 (300 ng/ml) or co-culture with CAFs or co-cultured with CAFs in the presence of DMSO, U0126 (20 μM), IL-33 neutralizing antibody (3 μg/ml) or ST2L neutralizing antibody (3 μg/ml). p and r Densitometric analysis shows the expression level of EMT markers in GC cells stimulated by the above factors. Data are represented as the mean ± SD of three independent experiments; *P <0.05, **P <0.01, ***P <0.001