Fig. 4

The effect of MSLN on NSCLC penetration of the BBB is dependent on MET. A,B Representative images and quantification analysis of MSLN and MET staining in primary lung tumor (LT, n=25) and lung cancer-derived brain metastases (BM, n=25) surgical specimens (scale bar, 200 μm). C Correlation of MSLN and MET protein expression in BM surgical specimens. D, E Representative western blot images showing the expression of MSLN, p-MET and MET in the indicated cells. F, G Representative images and quantitative results of western blotting for MET expression in tumor cells after transfection. H Effect of MET on the ability of NSCLC cells to penetrate the endothelium. I, J After treatment of hBMVECs with conditioned medium from the designated tumor cells for 24 h, western blot analysis and immunofluorescence detection showed the distribution of VE-cadherin, JAM-A and claudin-5 expression in hBMVEC monolayers (scale bar, 20 μm). (PC9-NC, PC9 cells transfected with negative control plasmid. PC9-OE, PC9 cells transfected with MSLN plasmid. PC9-BrM-NC, PC9-BrM cells transfected with negative control shRNA. PC9-BrM-SH1, PC9-BrM cells transfected with MSLN-targeted shRNA1. PC9-BrM-SH2, PC9-BrM cells transfected with MSLN-targeted shRNA2. PC9-BrM-SIR-1, PC9-BrM cells transfected with MET-targeted siRNA-1. PC9-BrM-SIR-2, PC9-BrM cells transfected with MET-targeted siRNA-2. PC9-BrM-SH2-NC, PC9-BrM-SH2 cells transfected with negative control plasmid. PC9-BrM-SH2-OE, PC9-BrM-SH2 cells transfected with MET plasmid. MET-SIR-1, PC9-BrM cells transfected with MET-targeted siRNA-1. shMSLN, PC9-BrM cells transfected with MSLN-targeted shRNA1. MET-OE, PC9-BrM cells transfected with MET plasmid.Data are presented as mean ± SD, ns, no significance)