Objective: To investigate the expression and localization of aquaporin-5 (AQP5) in epithelial ovarian tumors and its clinic significance.
Methods: The expression of AQP5 protein and mRNA in 65 cases epithelial ovarian tumors and 13 cases normal tissue were measured by immunohistochemical technique, Western blotting and RT-PCR, respectively.
Results: AQP5 is mainly localized in the basolateral membranes of benign tumor cells, the apical and basolateral membrane of borderline cells and scattered in the membrane of malignant cells and almost no or weak staining in normal ovarian epithelium. The AQP5 expression in ovarian malignant and borderline tumors was significantly higher than that of benign tumors (P < 0.05) and normal tissue (P < 0.05). Of all the epithelial ovarian malignant tumors, the AQP5 expression in cases with ascites volume more than 1000 ml was higher than that of ascites volume less than 500 ml (P < 0.05). Increased AQP5 protein level was associated with lymph node metastasis (P < 0.05). There is a positive correlation between ascites amount and the expression of AQP5 protein and mRNA (P < 0.05), as well as lymph node metastasis and the expression of AQP5 protein and mRNA (P < 0.05). The AQP5 expression was not related with FIGO stage, grade and histological type (P > 0.05).
Conclusion: The data suggest that overexpression of AQP5 play an important role in tumorigenesis of epithelial ovarian tumors, which may be related to the ascites formation of ovarian carcinoma.