Expression of integrin-linked kinase in lung squamous cell carcinoma and adenocarcinoma: correlation with E-cadherin expression, tumor microvessel density and clinical outcome.

Integrin-linked kinase (ILK) plays a role in integrin signaling-mediated cell-extracellular matrix interactions and is involved in signal transduction pathways to control cell survival, differentiation, and proliferation in mammalian cells. ILK has been implicated in the progression of several human malignancies. However, its function in malignant tumors is not fully enunciated. Previous in vitro studies also implicated ILK in the regulation of E-cadherin expression and vascular endothelial growth factor expression. In the current study, we investigated the protein expression of ILK and its correlation with clinicopathological profiles, E-cadherin expression, microvessel density (MVD) and clinical outcome in 57 lung squamous cell carcinoma and 44 adenocarcinoma, using immunohistochemistry. No ILK was detected in normal bronchial epithelium, while it was positively expressed in 39 (68.42%) squamous cell carcinoma cases and 27 (61.36%) adenocarcinoma cases. Positive ILK expression was significantly associated with advanced TNM stage (P = 0.022) in adenocarcinoma, and associated with high MVD in lung squamous cell carcinoma (P < 0.001) and adenocarcinoma (P = 0.049). The Spearman's correlation test revealed that increased ILK expression was correlated with reduced E-cadherin expression in lung squamous cell carcinoma (correlation coefficient = 0.364, P = 0.005). Moreover, the Kaplan-Meier survival analysis showed that ILK, E-cadherin, and MVD were all statistically significant prognostic factors in patients with lung squamous cell carcinoma and adenocarcinoma. Measuring ILK and E-cadherin expression, and MVD may contribute to a better understanding of the prognosis of patients with lung squamous cell carcinoma and adenocarcinoma.