Regulation of progesterone receptor gene expression.
The levels of progesterone receptor (PR) mRNA, PR protein, and [3H]R5020 binding activity were measured in parallel experiments conducted on a T47D subline expressing the estrogen receptor. A significant increase of PR mRNA levels could be detected within 6 h of exposure of the cells to estradiol (10(-8) M). The changes in mRNA, however, did not lead to any variation of PR protein levels of [3H]R5020 binding activity. A parallel analysis of PR mRNA and [3H]R5020 binding was then performed in a series of tumor biopsies. In estrogen receptor-positive and PR-positive tissues a correlation among the two values was found. It is postulated that the above mentioned data could reflect the existence of a difference in the mechanisms controlling the numerous steps of the PR synthesis in the various hormone-responsive tissues. This variability could allow an organ-specific response to the cyclic changes of circulating hormone.
Vegeto
E
E
Milano Molecular Pharmacology Laboratory, University of Milan, Italy.
Cocciolo
M G
MG
Raspagliesi
F
F
Piffanelli
A
A
Fontanelli
R
R
Maggi
A
A
D015152:Blotting, Northern; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007700:Kinetics; D009369:Neoplasms / Q000235:genetics* / Q000378:metabolism; D011397:Promegestone / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000302:isolation & purification; D011960:Receptors, Estrogen / Q000032:analysis; D011980:Receptors, Progesterone / Q000032:analysis / Q000235:genetics* / Q000378:metabolism
D012333:RNA, Messenger; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D011397:Promegestone