Overexpression of FXYD-3 is involved in the tumorigenesis and development of esophageal squamous cell carcinoma.

OBJECTIVE: To investigate the association of FXYD-3 expression with clinicopathological variables and PINCH in patients with ESCC. PATIENTS AND METHODS: Expression of FXYD-3 protein was immunohistochemically examined in normal esophageal mucous (n = 20) and ESCC (n = 64). RESULTS: Expression of FXYD-3 in the cytoplasm markedly increased from normal esophageal epithelial cells to primary ESCC (P = 0.001). The expression of FXYD-3 was correlated with TNM stages and depth of tumor invasion. Furthermore, the cases with lymph node metastasis tended to show a higher frequency of positive expression than those without metastasis (P = 0.086), and FXYD-3 expression tended to be positively related to the expression of PINCH (P = 0.063). Moreover, the cases positive for both proteins had the highest frequency of lymph node metastasis (P = 0.001). However, FXYD-3 expression was not correlated with patient's gender (P = 0.847), age (P = 0.876), tumor location (P = 0.279), size (P = 0.771), grade of differentiation (P = 0.279), and survival (P = 0.113). CONCLUSION: Overexpression of FXYD-3 in the cytoplasm may play an important role in the tumorigenesis and development in the human ESCC, particularly in combination with PINCH expression.