Activation of AXL and antitumor effects of a monoclonal antibody to AXL in lung adenocarcinoma.

BACKGROUND/AIM: AXL (anexelekto) has been explored as a potential novel therapeutic target for non-small cell lung carcinoma (NSCLC) but its activation status has not been evaluated in NSCLC. PATIENTS AND METHODS: We first immunolocalized the phosphorylated form of AXL in 112 lung adenocarcinoma cases and subsequently evaluated the anti-neoplastic effects of monoclonal antibody AXL in two lung adenocarcinoma cell lines, PC9 and A549. RESULTS: Phospho-AXL immunoreactivity was detected in 59.8% of adenocarcinoma cases examined and tended correlate significantly with larger tumor size (p=0.08) and with overall survival of the patients (p=0.041). Results of in vitro analysis revealed that the monoclonal antibody to AXL significantly inhibited cell proliferation of PC9 and A549, lung adenocarcinoma cell lines, which was caused by an inhibition of extracellular signal-regulated kinase (ERK) activation. CONCLUSION: AXL-targeted therapy, possibly through inhibiting ERK activation of carcinoma cells, could confer clinical benefits on patients with lung adenocarcinoma.