Cytoskeletal responsiveness to progestins is dependent on progesterone receptor A levels

Cytoskeletal responsiveness to progestins is dependent on progesterone receptor A levels.

Changes in the cell cytoskeleton occur in cell transformation and recent data suggest the involvement of ovarian hormones, which are implicated in cancer development and progression. In human breast and endometrial tumors, there is disrupted expression of progesterone receptor (PR) isoforms and predominance of one isoform, usually PRA. PRA predominance is an early event in carcinogenesis, and i...

Second International Symposium Progestins, Progesterone Receptor Modulators, and Progesterone Antagonists.

Histological evaluation of in vitro responses of endometrial adenocarcinoma to progestins and their relation to progesterone receptor levels.

In vitro responsiveness of endometrial adenocarcinoma to progestins was evaluated histologically by incubation of tissue fragments in medium containing 10(-6) M medroxyprogesterone acetate. In a series of 19 experiments, formation of sub- and supranuclear vacuoles, which reflects accumulation of glycogen in response to medroxyprogesterone acetate added to the medium, was observed in well-preser...

Pregnancy, progesterone and progestins in relation to breast cancer risk.

In the last two decades the prevailing opinion, supported by the "estrogen augmented by progesterone" hypothesis, has been that progesterone contributes to the development of breast cancer (BC). Support for this opinion was provided by the finding that some synthetic progestins, when added to estrogen in hormone replacement therapy (HRT) for menopausal complaints, increase the BC risk more than...

In vitro effects of progesterone and progestins on vascular cells.

The impact of progesterone on the cardiovascular system is relevant, but not as well characterized as the effects of estrogens. The recent early interruption of the conjugated equine estrogens (CEE)-medroxyprogesterone acetate (MPA) arm of the Women's Health Initiative trial, but not of the parallel CEE-only treatment arm, suggesting the possibility of harmful cardiovascular effects of the prog...