Background: The clinical significance of Brachyury expression and its relationship to epithelial-mesenchymal transition in primary lung carcinoma is unclear.
Methods: Expression of Brachyury mRNA was investigated in 104 surgically resected primary lung carcinoma tissues. Immunohistochemical analysis of Brachyury transcription factor, Slug, E-cadherin, IL-8, N-cadherin, and Ki67 was performed in 67 of 104 cases, and their expression was correlated to prognoses and clinicopathological factors.
Results: Brachyury mRNA expression in primary lung carcinoma tissues was a significant predictor of poor prognosis for 5-year disease-free survival and overall survival rates and was significantly correlated to vascular invasion, lymphatic permeation, histological grade, pathologic T stage, and pathologic N stage (P < 0.05). Brachyury mRNA expression was significantly inversely correlated to E-cadherin expression (P = 0.0252) and positively correlated to IL-8 protein (P = 0.0241) and to Slug protein (P = 0.0243) in adenocarcinoma tissues.
Conclusions: A positive association between Brachyury and Slug and IL-8, and a negative association with E-cadherin may lead to invasiveness and metastasis in primary lung carcinoma. Brachyury mRNA expression is a significant predictor of poor prognosis in primary lung carcinoma.