Objective To investigate the expressions of CDC25A and Smad3 in esophageal squamous cell carcinoma and the relationship of CDC25A with Smad3 protein

cell apoptosis

proliferation index (PI).   Methods The expression of CDC25A was examined by SP immunohistochemical stain (IHC) in 52 esophageal carcinoma specimens and 24 normal tissues. Moreover

CDC25A protein

Smad3 protein

cell apoptosis

proliferation index (PI) were examined by FCM in 30 esophageal carcinoma specimens and 5 normal tissues.    Results The positive expression rate of CDC25A in esophageal carcinoma  was 50%

significantly higher than 0% in normal tissues (P0.05). High expression of CDC25A was correlated with invasion

tumor differentiation and metastasis of esophageal squamous cell carcinoma (P0.05). The positive expression of Smad3 protein in esophageal carcinoma was significantly lower than that in normal tissues (P0.05 ). CDC25A protein expression was negatively associated with Smad3 protein expression (P0.05). The apoptosis rate in the cells with the positive expression of CDC25A protein in cytoplasm was higher than that of negative CDC25A expression

but without statistical significance. PI of the cells with the positive expression of CDC25A protein in nuclear membrane was higher than that of negative expression (P0.05).   Conclusion The reduction of Smad3 protein was correlated with the abundance of CDC25A protein. The CDC25A protein in nuclear membrane might contribute to cell proliferation. CDC25A protein may be involved in the carcinogenesis and progression of esophageal squamous cell carcinoma.