Abstract | OBJECTIVES: MATERIALS AND METHODS: RESULTS: All three estrogens increased the proliferation of MCF-7 cells by between 40 and 180%. The most proliferatively potent estrogen was E(2), followed by Eq and Dheq, which showed a slightly lower proliferative activity than E(2). The addition of progesterone inhibited E(2)-induced proliferation by about 30%, but only at the high non-physiological concentration of 10 mumol/l. All three progestogens inhibited Eq-induced proliferation, although their effect tended to be low, with values between 5 and 40%. No progestogen reduced Dheq-induced proliferation by more than 20%. In contrast, MPA slightly increased the proliferation rate by about 5% at the high physiological concentration of 0.1 mumol/l when combined with Dheq. The same held true when MPA and NET were added at the high pharmacological concentration of 10 mumol/l, causing increases of about 10%. CONCLUSIONS: Our results indicate that equine estrogens have a proliferative action similar to that of 17beta-estradiol. Continuous addition of progestogens does not result in any major reduction of proliferative potency. Some progestogens may even enhance the estrogen-induced proliferation of pre-existing breast cancer cells, particularly when combined with certain equine estrogens. However, in none of the tested circumstances do progestogens increase the proliferative effect of estradiol, and progesterone has no deleterious effect even at pharmacological levels, in contrast to progestogens.
|
Authors | A O Mueck, H Seeger, D Wallwiener |
Journal | Climacteric : the journal of the International Menopause Society
(Climacteric)
Vol. 6
Issue 3
Pg. 221-7
(Sep 2003)
ISSN: 1369-7137 [Print] England |
PMID | 14567770
(Publication Type: Comparative Study, Journal Article)
|
Chemical References |
- Estrogens, Conjugated (USP)
- Progestins
- Equilin
- Progesterone
- Estradiol
- dihydroequilin
- Medroxyprogesterone Acetate
- Norethindrone
|
Topics |
- Breast Neoplasms
(metabolism, pathology)
- Cell Division
(drug effects)
- Dose-Response Relationship, Drug
- Equilin
(analogs & derivatives, pharmacology)
- Estradiol
(pharmacology)
- Estrogens, Conjugated (USP)
(pharmacology)
- Female
- Humans
- Medroxyprogesterone Acetate
(pharmacology)
- Norethindrone
(pharmacology)
- Progesterone
(pharmacology)
- Progestins
(pharmacology)
- Tumor Cells, Cultured
|