Role of AXL expression in non-small cell lung cancer

The present study aimed to investigate the expression profile of AXL in non-small cell lung cancer (NSCLC) and its clinical significance. The current study included 257 NSCLC patients, tyrosine-protein kinase receptor UFO (AXL) expression in paired lung cancer and adjacent normal lung tissues of NSCLC patients were compared by immunohistochemistry, western blot analysis and quantitative polymerase chain reaction (qPCR). These methods were used to detect the expression of the AXL gene and protein in fresh tissues from 35 patients. Small interfering RNA (siRNA) was transfected into the H1299 lung cancer cell line to knock down AXL expression; the effects of AXL-siRNA on cell proliferation and migration were examined by MTT and Transwell migration assay, respectively. It was found that AXL staining density in lung cancer tissues was significantly increased compared with adjacent normal lung tissues (55.25 vs. 26.85%; P<0.01); and the expression level of AXL in NSCLC patients was significantly associated with the degree of tumor differentiation (P<0.01) and the clinical stage of disease (P<0.01). Western blotting and qPCR showed that AXL expression was significantly higher in cancer tissues compared with that in adjacent lung tissue (P<0.05). Additionally, the current study also showed that AXL-siRNA inhibited H1299 cell proliferation and migration in vitro. The present study demonstrates the association between increased expression of AXL in NSCLC and the low differentiation phenotype, and its effects on cell proliferation and migration, suggesting its potential clinical values for the prognosis of NSCLC.