總結(jié) |
There is accumulating evidence to suggest that progesteroneplaysan essential role in the regulation of growth and differentiationof mammary glands and thus mayplay a key role in breast cancer (Edwards, 2005). The biological response to progesterone ismediated by two distinct formsof the human progesterone receptor (PR-A and PR-B forms). Inmost cellcontexts, the B form functions as a transcriptional activator, whereas the A formfunctions as a transcriptionalinhibitor of steroid hormones (Attia et al., 2000; Lin et al., 2003).Recently it has been demonstrated that there is differential hormone dependent regulation of thephosphorylation of the A and B forms of the receptor (Clemm et al., 2000) . Treatment of T47Dbreast cancer cells with progestin agonist increases the phosphorylation of Ser190and Ser294with different kinetics. These phosphorylation events may differentially affect the transcriptionalactivity of the receptor.
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