Anterior gradient 2 is correlated with EGFR mutation in lung adenocarcinoma tissues.

Abstract Epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) has demonstrated a promising therapeutic response in lung adenocarcinoma patients with EGFR gene mutations. However, the predictive factors for this therapy have not been established, except for the EGFR gene mutation status of carcinoma cells. We first performed microarray analysis in EGFR-TKI-sensitive lung adenocarcinoma cell lines. The results indicated anterior gradient 2 (AGR2) as a potential surrogate marker of EGFR-TKI. Therefore, we then evaluated the correlation between the status of AGR2 immunoreactivity and clinicopathological factors including overall survival (OS), progression-free survival (PFS) and clinical response to EGFR-TKI, in 147 cases of surgically resected lung adenocarcinoma. The biological significance of AGR2 was further evaluated by transfecting small interfering RNA (siRNA) against AGR2 in these cells. The status of AGR2 immunoreactivity was significantly higher in lung adenocarcinoma cases with EGFR gene mutations than in those with the wild type (p