Overexpression of Stathmin 1 correlates with poor prognosis and promotes cell migration and proliferation in oesophageal squamous cell carcinoma.

Stathmin 1 (STMN1) is a microtubule-regulated protein that plays an important role in tumour cell proliferation and migration. Overexpression of STMN1 is associated with clinicopathological characteristics in many human cancers. The aim of the present study was to investigate STMN1 expression, its correlation with clinicopathological characteristics, and its exact biological function in oesophageal squamous cell carcinoma (ESCC). STMN1 levels were measured in the ESCC tissue specimens of 276 patients by immunohistochemistry (IHC) to assess the prognostic efficacy of STMN1. IHC showed that patients with overexpression of STMN1 had a poorer prognosis compared with those with low expression, both in regards to 5-year overall survival (OS; 21.2 vs. 53.7%, P<0.001) and disease-free survival (DFS; 20.6 vs. 50.9%, P<0.001). STMN1 overexpression was associated with lower cell differentiation in tumour grade (correlation coefficient: 0.127, P=0.037). In multivariate analysis, STMN1 expression was found to be an independent prognostic factor for both OS (P<0.001; 95% CI, 1.555-2.970) and DFS (P=0.001; 95% CI, 1.978-2.444). Compared with the control, STMN1 downregulation significantly decreased cell migration, invasion and proliferation, whereas these were increased by STMN1 upregulation. STMN1 expression was significantly associated with prognosis and tumour differentiation in ESCC, indicating that STMN1 expression is an independent prognostic factor for ESCC and could be a potential biomarker. Regulating the expression of STMN1 could influence tumour cell motility, invasion and proliferation.