The Role of Prolactin in Mammary Cancer PRL action in the cell cycle.
Prolactin is an important regulator of mammary gland differentiation and growth.
These diverse effects suggest that role of these related hormones in breast cancer is also likely to be complex, involving multiple signaling pathways and dependent on hormone and growth factor context. Prolactin production within the mammary epithelial cells themselves further obfuscates these processes. In order to understand these issues, we have derived mammary cell lines which no longer express prolactin, and are employing transgenic mouse models to explore outcome in an in vivo context. Our studies have demonstrated effects of prolactin on several cell cycle regulators, including transcriptional regulation of cyclin D1. Our development of the rNRL promoter, a non-hormonally responsive, mammary specific promoter, in conjunction with Drs.