Estradiol-17beta regulates vascular endothelial growth factor and Bcl-2 expression in HHUA cells

HHUA, a rare endometrial cancer cell line expressing the estrogen receptor (ER), was adopted to investigate the expression of vascular endothelial growth factor (VEGF), erythropoietin (Epo), Bcl-2 and p53 under the administration of estradiol-17beta (E2). Based on quantitative real-time reverse transcription polymerase chain reaction assays, both VEGF and Bcl-2 mRNA levels decreased in a dose-dependent manner, although VEGF levels were increased in a time-dependent manner; no significant change was found for Epo and p53. An immunocytochemical study also showed the suppressed expression of VEGF and Bcl-2 under E2 induction. Both ERalpha and ERbeta mRNAs were detected in HHUA cells with ERbeta expression being predominantly higher than that of ERalpha, which is the converse of the pattern seen in normal endometria. The present study shows the E2-downregulated expression of VEGF and Bcl-2, and reveals a disrupted balance of ERalpha and ERbeta expression, which should be taken into consideration to understand the particularity of E2-regulated gene expression in HHUA cells.