Src Promotes Metastasis of Human Non-Small Cell Lung Cancer Cells through Fn14-Mediated NF-κB Signaling

BACKGROUND: Src and Fn14 are implicated in the aggressiveness of non-small cell lung cancer (NSCLC) cells, yet the molecular mechanism is not fully understood. MATERIAL/METHODS: The proliferation, migration, and invasion of HCC827 cells with Src knockdown were examined in vitro. The expression of Fn14 and the activation of NF-κB signaling pathway in Src-silenced HCC827 cells were detected by western blot. The role of Fn14 in Src-regulated cell migration/invasion and activation of NF-κB signaling was investigated by overexpressing Fn14 in Src knockdown NSCLC cells. Furthermore, the pro-metastatic role of Src was validated in a NSCLC metastasis mouse model. RESULTS: Knockdown of Src inhibited the proliferation, migration, and invasion of HCC827 cells, which was associated with reduced levels of Fn14, p-IκBα, p-IKKβ, and nuclear NF-κB p65. Overexpression of Fn14 restored the potential of migration and invasion as well as the activation of NF-κB signaling in Src-silenced NSCLC cells. In addition, silencing of Src suppressed lung metastasis of HCC827 cells in mice, and inhibited the expression of Fn14 and nuclear translocation of NF-κB p65 in vivo. CONCLUSIONS: The data demonstrated that the Src/Fn14/NF-κB axis plays a critical role in NSCLC metastasis.