Furthermore, the three proteins were upregulated or downregulated synchronously, even after RNA interference silencing of either Stat5 or Akt1. 
THERM
Controlled synchronization of prolactin/STAT5 and AKT1/mTOR in bovine mammary epithelial cells.The prolactin/STAT5 and AKT1/mTOR pathways play a key role in milk protein transcription and translation, respectively.  However, the correlation between them in bovine mammary epithelial cells remains unclear.  Cell proliferation and viability were examined using the CASY-TT assay.  Purified bovine mammary epithelial cells were cultured in differentiation media for different periods.  The basic differentiation medium contained a lactogenic hormone cocktail of insulin (5 μg/mL), hydrocortisone (1 μg/mL), and prolactin (5 μg/mL).  The cells cultured in this medium grew slowly and expressed higher levels of p-STAT5, p-AKT1, and p-mTOR (activated form) than those of control cells.  Although the phosphorylation ratio was not increased, transcription and translation of these proteins were upregulated by the addition of insulin-like growth factor-1 or growth hormone, which further increased β-casein mRNA expression.  Furthermore, the three proteins were upregulated or downregulated synchronously, even after RNA interference silencing of either Stat5 or Akt1.  These findings indicate that a few hormones and other factors play lactogenic and galactogenic roles by promoting two key lactogenic signaling associated with milk protein expression.  We provide evidence of prolactin/STAT5 and AKT1/mTOR synchronization, establishing a direct correlation between transcription regulation and translation regulation of milk protein in bovine mammary epithelial cells.
C