Fig. 4

Cancer cell-intrinsic IL-15 upregulates vimentin protein expression in an AKT-mTORC1-dependent manner. (A and B), A549 and PC9 cells were transfected with siRNA-IL-15 and siRNA-Ctrl or transduced with Lv-hIL-15 and Lv-Ctrl. The cells were lysed and subjected to immunoblot analysis of E-cadherin and vimentin expression (A). RNA was extracted from the abovementioned cells and subsequently, RT-qPCR was performed to measure VIM expression (B). (C), IL-15-overexpressing A549 and PC9 cells were transfected with siRNA-VIM or siRNA-Ctrl for 48 h. Transwell migration assays were subsequently performed. Scale bar, 100 μm. ****, p < 0.0001. (D), IL-15-overexpressing A549 and PC9 cells were treated separately with the inhibitors LY294002 (5 µM) and rapamycin (500 nM) for 24 h. Then, vimentin expression was assessed via immunoblot analysis. (E), IL-15-overexpressing A549 and PC9 cells were treated with cycloheximide (50 µM) for 8 h and lysed for immunoblot analysis of E-cadherin and vimentin expression. Immunoblotting was also performed for β-actin as the protein loading control