Expression of angiopoietin-2 in esophageal squamous cell carcinoma and its significance

Objective To analyze expression of angiopoietin-2 (Ang-2) protein in human esophageal squamous cell carcinoma (ESCC),and to investigate the relationship between Ang-2 protein and clinicopathologic factors.Methods 60 cases of ESCC,5 cases of latero-carcinoma tissues and 30 cases of normal tissue were immunohistochemically stained using Ang-2 monoclonal antibodies with PV-9000 non-biotin detection system.The positive expression rate and expression level of Ang-2 were evaluated.Results Ang-2 was mainly expressed in cytoplasm.The positive expression rates in normal epithelium,latero-carcinoma tissues and ESCC were respectively 3.33 ％ (1/30),40.00 ％ (2/5),53.33 ％ (32/60).Compared ESCC with normal epithelium and latero-carcinoma tissues,Ang-2 positive expression rate was significantly higher (P ＜ 0.05).Among ESCC,expression of Ang-2 was positively correlated with the tumor infiltration depth (rs =0.621,P =0.002),and inversely correlated with tumor differentiation status (rs =-0.309,P =0.018).Conclusions Ang-2 may play an important role in the carcinogenesis and development of ESCC.Tumor differentiation degree,infiltration depth and TNM staging are the independent prognostic indicators for ESCC patients.Combinative detecting the expression of Ang-2 may provide more accurate information in early diagnosis and predicting the prognosis of ESCC. Key words: Esophageal neoplasms;  Carcinoma, squamous cell;  Angiopoietin-2; Immunohistochemistry