The influence of aquaporin-1 and microvessel density on ovarian carcinogenesis and ascites formation

This study aimed at investigating aquaporin-1 (AQP1) distribution and expression in primary ovarian epithelial tumors, correlating with clinicopathologic variables and intratumoral microvessel density (IMD). The AQP1 expression and IMD in 105 cases with primary epithelial ovarian tumors were measured by semiquantitative immunohistochemical technique. AQP1 was located mainly in microvessels and small vessels but seldom in tumor cells. Expression of AQP1 and IMD in ovarian malignant tumors was significantly higher than that in borderline tumors (P = 0.000, P = 0.001, respectively), and that in borderline tumors was higher than in benign tumors (P = 0.008, P = 0.028, respectively). The expression of AQP1 in FIGO stage III-IV was more than that in stage I-II (P = 0.001), and cases with ascites volume greater than 1000 mL were more than cases with ascites volume less than 1000 mL (P = 0.000). There is a positively correlated relationship between expression of AQP1 and IMD (correlation coefficient 0.60, P = 0.000) and between expression of AQP1 and ascites volume (correlation coefficient 0.57, P = 0.000). These data implicate that high AQP1 expression may play an important role in the ovarian carcinogenesis, progression, and ascites formation. Further studies into the mechanism of AQP1 regulation and the relationship between AQP1 expression and tumor angiogenesis may lead to novel therapies for ovarian carcinoma.