Localisation and expression of aquaporin subtypes in epithelial ovarian tumours

Jian-Hua Yang, Yu-Qun Yu and Chun-xiao Yan

Department of Gynaecology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.

Offprint requests to: Jia-Hua Yang, Ph.D. Department of Gynaecology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, China. e-mail: yjh0121@126.com


Summary. To characterise AQP subtype localisation and expression in epithelial ovarian tumours, immunohistochemistry was used to assess the localisation and expression of AQP1-9 in 30 benign tumour cases, 30 borderline tumour cases, 50 malignant tumour cases and 20 normal ovarian tissue cases. Multiple AQP subtypes were expressed in epithelial ovarian tumours, with each AQP subtype displaying a different pattern of localisation and expression. AQP1 was mainly expressed in the microvascular endothelium, and AQP 2-9 were mainly expressed in tumour cells. Most AQP subtypes co-localised in the basolateral membranes of the epithelia of benign tumours and plasma membranes of malignant tumour cells. The positive rates for AQP1, 5, 6, 7, 8, and 9 were over 50%, but those for AQP2, 3 and 4 were only 10-40%. The expression of AQP1, 5 and 9 in malignant and borderline tumours was significantly higher than that in benign tumours (P<0.05) and normal ovarian tissue (P<0.05). However, AQP6 expression in ovarian malignant and borderline tumours was significantly lower than that in benign tumours (P<0.01) or normal ovarian tissue (P<0.01). AQP1 expression was increased in cases with ascites volumes greater than 1000 mL (P<0.05), AQP5 expression was greater in cases with lymph node metastasis (P<0.05), and more AQP9 expression was observed in G3 cases versus G1 and G2 cases (P<0.01). These results suggest that changes in the distribution and expression of AQP subtypes may be involved in ovarian carcinogenesis. This study presents a novel avenue of research that could illuminate the mechanism of ovarian carcinogenesis and treatment. Histol Histopathol 26, 1197-1205 (2011)

Key words: Epithelial ovarian tumours, Aquaporins, Localisation, Water, Glycerol

DOI: 10.14670/HH-26.1197