17β-estradiol accelerates ovarian tumour progression in vivo though the upregulation of GREB1

Exogenous 17β-estradiol (E2) accelerates the progression of ovarian cancer in the transgenic tgCAG-LS-TAg mouse model of the disease. We hypothesized that E2 has direct effects on ovarian cancer cells and this study was designed to determine the molecular mechanisms by which E2 accelerates ovarian tumour progression. Mouse ovarian cancer ascites (MASE2) cell lines were derived from tgCAG-LS-TAg mice. Following intraperitoneal engraftment of MASE2 into SCID mice, exogenous E2 significantly decreased the survival time and increased the tumour burden. Microarray analysis performed on cells derived from mouse ovarian cancer ascites (MASE2) treated with and without E2 indicated that E2 treatment caused the upregulation and downregulation of genes involved in cell differentiation, proliferation and migration. In particular, Greb1 that has been also identified as a hormone-responsive gene in breast cances, was upregulated in mouse tumour cells treated with E2. Three biological replicates (MASE2 tumours grown in SCID mice, see growth protocol) were analyzed for both conditions of addition of E2 or placebo.