Discoidin domain receptor 1 promotes lung adenocarcinoma migration via the AKT/snail signaling axis

Discoidin domain receptor 1 (DDR1), a member of receptor tyrosine kinase, has been implicated in tumor progression. However, the function and underlying mechanism of DDR1 in lung adenocarcinoma (LUAD) progression is unclear. Thus, we explored the molecular regulatory mechanism of DDR1 in the migration of LUAD.

Transwell assays, wound healing assays and xenograft tumor assays were performed to study the function of DDR1 in the progression of LUAD. Immunoblotting and quantitative real-time polymerase chain reaction (RT-qPCR) were used to detect the expression levels of genes. Co-immunoprecipitation (co-IP) assays were performed to detect the interaction between DDR1 and AKT. Immunofluorescence and immunohistochemistry assays were used to determine the expression level of proteins in cells and tissues, respectively.

DDR1 expression was significantly higher in LUAD tissues than in normal lung tissues, and the level of DDR1 was inversely correlated with prognosis in patients. We found that DDR1 promoted the migration and invasion of LUAD cells in vitro. Furthermore, ectopic expression of DDR1 in LUAD cells altered EMT-related markers expression. Importantly, the DDR1 protein interacted with AKT and phosphorylated AKT. The AKT inhibitor MK2206 interrupted Snail upregulation in DDR1-overexpressing LUAD cells. Finally, our study revealed that depletion of DDR1 attenuated LUAD cell migration in a tumor xenograft mouse model.

Our findings uncovered that a high abundance of DDR1 increased the migration and invasion capability of LUAD cells via the AKT/Snail signaling axis and indicated that DDR1 could be a potential target for treating LUAD.