Fig. 6
LIFR–YAP1 signaling is critical for LIF-mediated invasion of NPC cells. a Endogenous protein expression of LIFR, p-YAP1(S127), and YAP1 in three cancer cell lines. b Immunostaining for YAP1 and LIFR in three cancer cell lines. Scale bars, 10 μm. c Western blot analysis of LIFR and p-YAP1 (S127) protein levels in WT and cLIF cancer cells transfected with SMARTpool LIFR siRNA or control siRNA. The p-YAP1 (S127) expressions with respect to total YAP1 levels were quantified and presented as mean ± SEM (n = 3). At least three independent experiments were performed. d Western blot analysis of expression of focal adhesion molecules and SRC in WT and LIF+/− cancer cells transfected with YAP1 siRNA. GAPDH was used as the loading control. e Representative images for p-PXN (Y118) expression in WT or LIF+/− cancer cells transfected with YAP1 or control siRNA (n = 3). Alexa Fluor 488 phalloidin (green) was used to stain F-actin. Scale bars, 10 μm. f Representative images of the HUVEC layer replacement assay. Fixed numbers of WT or LIF+/− cancer cells transfected with YAP1 or control siRNA were plated onto the confluent HUVEC layer and co-cultivated for 24 h. Cancer cells were labeled with antibody against pan-cytokeratin (red) and HUVEC cells with antibody against VE-cadherin (green). Scale bars, 20 μm. g, h Quantification of displaced areas depicted in f. WT cancer cells (g). LIF+/− cancer cells (h). Invaded areas were calculated using CellSens imaging software (Olympus). Data are presented with scatter dot plot (mean ± SEM). Each black dot represents one captured image. Mann–Whitney test. i Immunohistochemistry for LIFR and YAP1 expression (brown) in consecutive NPC biopsy sections derived from primary or bone marrow metastatic lesions
