Liver kinase B1 correlates with prognosis and epithelial-mesenchymal transition of resectable early stage non-small cell lung cancer

BACKGROUND: Recent evidences support that low expression of liver kinase B1 (LKB1) triggers epithelial-mesenchymal transition (EMT) through induction of Zinc finger E-box binding homeobox 1 (ZEB1) expression, which downregulates E-cadherin in human lung cancer cell lines. However, the clinicopathological significance of LKB1, EMT, salt-inducible kinase 1 (SIK1), ZEB1 and their relationship in early stage non-small cell lung cancer (ES-NSCLC) patients remain to be determined. In this study, the correlation among expression of LKB1, risk of distant metastasis, prognostic significance, and EMT in ES-NSCLC after surgery was investigated by immunohistochemistry. METHODS: Case notes and pathology records of 103 patients with ES-NSCLC were retrospectively analyzed. Immunohistochemical staining was employed to detect LKB1, EMT biomarkers (E-cadherin and vimentin), SIK1 and ZEB1 expression in ES-NSCLC tissues. RESULTS: LKB1 expression is associated with distant metastasis after treatment (P=0.017). LKB1-high expression group has better overall survival (OS) (P=0.000) and disease-free survival (DFS) (P=0.000). LKB1 expression is correlated with E-cadherin (r=0.231, P=0.019), vimentin (r=−0.225, P=0.022), SIK1 (r=0.218, P=0.027) and ZEB1 (r=−0.242, P=0.014). CONCLUSIONS: Our findings suggest that LKB1-high expression is possibly associated with favourable prognosis and LKB1 expression is correlated with EMT and expression of SIK1 and ZEB1.