T-cell immunoglobulin and mucin domain 1 expression in human non-small-cell lung cancer tissues and its clinical significance

Abstract

Objective To investigate the expression of T-cell immunoglobulin and mucin domain 1 (TIM-1) in non-small-cell lung cancer (NSCLC) tissues and to analyze its clinical significance. To further explore the regulatory effect of TIM-1 intervention on the biological function of NSCLC cell lines. Methods The immunohistochemistry assay and the tissue micro-array were used to examine the TIM-1 expression in lung cancer tissues as well as adjacent normal lung tissues. The correlation between the expression level of TIM-1 and patients’ clinic pathological parameters was evaluated by using chi-square test. The lung cancer cell lines A549 and SK-MES-1 were used to construct the stable knockdown expression of TIM-1 using RNA interference (RNAi) method. The cell counting kit-8 (CCK-8), wound healing, and Transwell were used to examine the cellular function after TIM-1 knockdown of these cells. Results Higher TIM-1 expression in lung squamous cell carcinoma tissues is significantly correlated with advanced TNM stage (Ⅲ+ Ⅳ: 33.3%, Ⅰ+ Ⅱ: 13.2%) (χ2=3.969, P<0.05), but not any other parameters. CCK-8 assay showed that, knockdown expression of TIM-1 make the cell proliferation rate decreased significantly. The wound healing assay showed that the cell migration abilities of LV-TIM-1-shRNA group was significantly lower than LV-NC group (A549, 24 h: t=17.540, P<0.01; SK-MES-1, 24 h: t=11.450, P<0.01). The Transwell assay showed that the cell invasion abilities was significantly decreased after knockdown expression of TIM-1. Conclusion Our results showed that the TIM-1 was highly expressed in non-small-cell lung cancer tissues, and its expression level was significantly correlated with TNM stage in squamous cell carcinoma patients. TIM-1 expression in lung adenocarcinoma tissues could be used as independent prognostic predictor for the patients, while higher TIM-1 expression in lung squamous cell carcinoma tissues trends significant for the prognostic prediction for the patients. Knockdown expression of TIM-1 could inhibit the cell viability, and the abilities of migration and invasion, and thus TIM-1 could be used as potential therapeutic target for lung cancer. Key words: T-cell immunoglobulin and mucin domain 1; Lung cancer; Immunohistochemistry; RNA interference; Prognosis