The role of Hoxa7 and Pax8 in epithelial ovarian cancer differentiation

Epithelial ovarian cancer (EOC) is divided into several histological subtypes characterized by Mullerian-like differentiation and the expression of genes not expressed in normal ovarian surface epithelium. Many of these genes are implicated in female reproductive tract development, including Hoxa7 and Pax8, and it has been proposed that these genes are involved in the differentiation and progression of EOC. The effects of Hoxa7 overexpression (cellular proliferation, morphology, expression of E-cadherin and vimentin) were investigated in cell lines derived from our transgenic mouse models of ovarian cancer. However, Hoxa7 overexpression did not significantly affect any of these parameters. Immunohistochemical analysis revealed that Pax8 often appears to be localized to regions of papillary differentiation in tumours from transgenic tgMISIIR-TAg mice. These results suggest that while Hoxa7 alone does not drive EOC differentiation in vitro, expression of Pax8 may contribute to the differentiated epithelial features of ovarian cancer