Effect of 17β-estradiol, progesterone, synthetic progestins, tibolone, and tibolone metabolites on vascular endothelial growth factor mRNA in breast cancer cells

17β-estradiol, tibolone, and tibolone hydroxy-metabolites had no effect on VEGF mRNA in MCF-7 cells. Progesterone and progestins increased VEGF mRNA in T47-D breast cancer cells, but Δ4-tibolone was less effective than progestogens on this angiogenic gene in the T-47 D cells. This differential effect may be related to breast cancer growth.