Netrin-1 elicits metastatic potential of non-small cell lung carcinoma cell by enhancing cell invasion, migration and vasculogenic mimicry via EMT induction

Ectopic expression of netrin-1 has been validated in several cancers including non-small cell lung cancer (NSCLC). Recent research confirms the critical role of netrin-1 in NSCLC growth and its prognostic value. Unfortunately, its contribution in NSCLC metastasis remains elusive. Here, netrin-1 had relatively high expression in NSCLC tissues and cells, especially in high metastatic groups. Notably, netrin-1 overexpression aggravated the malignant metastatic behavior of NSCLC cells, including cell invasion, migration, and vasculogenic mimicry (VM), whereas netrin-1 depression reversely dampened the metastatic potential. Mechanism analysis confirmed that elevation of netrin-1 induced the typical morphological changes of epithelial-to-mesenchymal transition (EMT) and increased the expression of EMT markers, including E-cadherin down-regulation and N-cadherin up-regulation. Consistently, netrin-1 inhibition inversely antagonized the occurrence of EMT. Moreover, netrin-1 also activated the oncogenic pathways of PI3K/AKT and ERK signaling. More importantly, blocking these pathways with their antagonists LY294002 or U0126 reversed the effects of netrin-1 overexpression on cell invasion, migration, EMT, and VM formation. Collectively, the current data suggest that netrin-1 can act as a pro-metastatic factor in NSCLC by enhancing cell invasion, migration, and VM via PI3K/AKT and ERK-mediated EMT process, thereby implicating netrin-1 as a novel promising therapeutic target against aggressive NSCLC.