... the differentiation, maturation and maintenance of the secretory tissue, compromising lactation. The mutant epithelium displayed a decreased activation of STAT5, a key regulator of the lactogenic process primarily governed by prolactin. Data obtained with a mammary epithelial cell line suggested that defective STAT5...

... pregnancy. Mechanistically, Ptp1b deletion enhanced the expression of progesterone receptor and phosphorylation of Stat5, two key regulators of alveologenesis. Furthermore, glands from Ptp1b knockout mice exhibited increased expression of milk proteins during pregnancy due to enhanced Stat5 activation...

... and prolactin pathways by negatively regulating both PRL receptor expression and STAT5 phosphorylation, thereby impairing the subsequent transactivation of PRL target genes. Using HC11 cells as a model, we demonstrate that the effects of Tif1g knockdown on lactation depend on both SMAD4 and TGFβ. Interestingly...

... by the coordinated actions of TGF-β and prolactin. The elevated SnoN promotes Stat5 signaling by enhancing its stability, thereby sharply increasing the activity of prolactin signaling at the onset of lactation. SnoN –/– mice display severe defects in alveologenesis and lactogenesis, and mammary epithelial cells...

... during pregnancy, which in turn leads to premature involution of the gland. We further show that this developmental stage-specific ability of MYC to promote mammary epithelial differentiation is tightly linked to its ability to downregulate caveolin 1 and activate Stat5 in a developmental stage-specific...

... proliferation. Analysis of the mammary differentiation factor STAT5 by immunohistochemistry and western blot revealed a complete ablation of STAT5 activation in Erbb4 Flox/Flox Wap-Cre mammary epithelium at parturition. Consistent with disrupted STAT5 function, Erbb4 Flox/Flox Wap-Cre mammary glands...