Clinicopathological significance of Sip1-associated epithelial mesenchymal transition in non-small cell lung cancer progression

Background: Epithelial-mesenchymal transition (EMT) is a key event in cancer progression. The expression of EMT-related factors in non-small cell lung cancer (NSCLC) and their impact on clinicopathological variables was examined. Patients and Methods: A total of 137 NSCLC patients who underwent surgical resections were investigated. The expression of Twist, Snail, smad-interacting protein 1 (Sip1), E-cadherin, N-cadherin, vimentin and β-catenin was detected by immunohistochemical analyses. Results: The expression of Sip1 was associated with the reduced expression of E-cadherin (p=0.04) and the positive expression of N-cadherin (p=0.04). There was no association between the expression of Twist nor Snail and the epithelial or mesenchymal markers. The expression of Sip1 correlated with advanced T status (p=0.01), tumor diameter (p=0.01) and advanced stage (p=0.01). Furthermore, the expression of Sip1 was associated with poor postoperative overall survival (p=0.02). Conclusion: The expression of Sip1 is significantly associated with tumor growth and poor prognoses in NSCLC and EMT might be activated via Sip1 expression and result in accelerated tumor growth and poor survival in NSCLC.