Objective: To determine the effect of 17beta-estradiol, progesterone, medroxyprogesterone acetate, levonorgestrel, norethindrone, tibolone, and tibolone metabolites on vascular endothelial growth factor (VEGF) isoforms 121 and 165 mRNA in two breast cancer cell lines, MCF-7 (estrogen receptor rich) and T47-D (progesterone receptor rich), in vitro.
Design: Prospective basic research study.
Setting: Basic research laboratory.
Intervention(s): MCF-7 and T47-D cells were cultured to 80% confluence in vitro. After 24 hours' incubation in serum-free media, 1.0, 0.1, and 0.01 microM of 17beta-estradiol, tibolone, 3alpha-hydroxytibolone and 3beta-hydroxytibolone were added to MCF-7 cells. Progesterone, medroxyprogesterone acetate, levonorgestrel, norethindrone, and Delta4 tibolone at 1.0, 0.1, and 0.01 microM were added to T47-D cells. The cells plus steroids were incubated for a further 24 hours.
Main outcome measure(s): Isolation and identification of VEGF isoforms 121 and 165 using semiquantitative polymerase chain reaction, gel electrophoresis, with cyclophilin as an internal control.
Result(s): 17beta-estradiol, tibolone, 3alpha-hydroxytibolone, and 3beta-hydroxytibolone had no effect on VEGF mRNA in MCF-7 cells. Progesterone, medroxyprogesterone acetate, levonorgestrel, and norethindrone increased VEGF mRNA in T47-D cells. Delta4-Tibolone also increased VEGF mRNA but to a lesser extent than the progestogens.
Conclusion(s): 17beta-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 Delta4-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.