Figure 3:Effect of SMAD4 knockdown or miR-205 overexpression on the proliferation of NSCLC cells. A Effect of siRNA-based knockdown on mRNA expression of Smad4 . B Validation of siRNA-based knockdown effect in Smad4 in NSCLC A549 cells and SPC-A1 cell lines. The knockdown effect of Smad4 was assessed by immunoblotting analyses. C-D Effect of siRNA-based Smad4 knockdown or miR-205 overexpression on the proliferation of A549 cells. Tumor cells were transiently transfected with siRNA against Smad4 or miR-205, followed by harvesting cells at indicated times for assay of cell proliferation. *p<0.05; **p<0.001; ***p<0.001.