Positive immunostaining of claudin-7, ephrin receptor A1 and Forkhead Box M1 in EOC was consistent with the upregulation of these genes in the microarray result.
Moreover, CLDN-7 was highly expressed in 2774 and HeyA8 human ovarian cancer cells and inhibition of CLDN-7 by its siRNA significantly enhanced the sensitivity of 2774 and HeyA8 cells to cisplatin treatment.
Similarly, immunohistochemical analysis and western blotting showed that claudin-7 protein was significantly overexpressed in the vast majority of EOCs.
Out of those seven, claudin-1, an adhesion molecule and phenotypic epithelial marker, is the only independent biomarker of serous epithelial ovarian carcinoma.
CLDN-7 is significantly overexpressed in all main histologic types of EOC and in single neoplastic cells disseminated in peritoneal cavity and pleural effusions, suggesting its potential role as novel diagnostic marker in ovarian cancer.