Inhibition of CXCR4 regulates epithelial mesenchymal transition of NSCLC via the Hippo-YAP signaling pathway

CXCR4 has been shown to play a key role in the metastasis of non-small cell lung cancer (NSCLC). And CXCR may be associated with the HippoYes kinase-associated protein (YAP) pathway, thus involving in the occurrence and progression of NSCLC. This study aims to investigate the effect of CXCR4 inhibition on epithelial-mesenchymal transition (EMT), invasion and migration of NSCLC cells via the Hippo-YAP pathway. QRT-PCR and Western blot were employed to detect CXCR4 expression in NSCLC cell lines. A549 and H1299 cells were treated with WZ811 (0, 10, 30, and 50 mu M), and A549 cells were also divided into the Control, WZ811, YAP siRNA, and WZ811+YAP groups. Wound-healing, Transwell assay, immunofluorescent staining, and a luciferase reporter gene assay were performed in this experiment. Compared with human bronchial epithelial (HBE) cells, CXCR4 expression was up-regulated in NSCLC cell lines. WZ811 increased E-cadherin; decreased expression of Twist, vimentin, Snail, p-YAP, CTGF, and BIRC5; blocked GTIIC reporter activity; and reduced migration and invasion of A549 cells, all in a dose-dependent manner. YAP siRNA had a similar effect to WZ811 by inhibiting EMT, invasion and migration of A549 cells. However, compared with A549 cells in the YAP siRNA and WZ811 groups, cells in the WZ811+YAP group showed a dramatically enhanced EMT phenotype as well as invasion and migration abilities. Inhibition of CXCR4 may reduce EMT, invasion and migration of NSCLC cells, thereby providing a new therapeutic target for NSCLC.