STAT1/STAT2 knockdown reduces IFITM1 and PLSCR1 expression. (A and B) MCF-7:5C cells were transfected with sicontrol (siCon), STAT1 siRNA (siSTAT1) or STAT2 siRNA (siSTAT2) and STAT1, STAT2, IFITM1 and PLSCR1 protein levels were assessed at 24 and 48 hours by Western blot analysis (left panels). Transfected cells were also treated with E2 for an additional 24 and 48 hours and the above mentioned proteins were also measured (a and b, left panels). (A, B) Cell proliferation was measured in siSTAT1-knockdown and STAT2-knockdown cells in the presence or absence of E2 by cell titer blue assay (right panels). Each value is a mean ± SD from three experiments. *P <0.05 or **P <0.01 versus the control; #P <0.05 versus E2 treatment. (C) MCF-7:5C cells were transfected with Bax siRNA (siBax) or Noxa siRNA (siNoxa) for 24 hours and then treated with 1 nM E2 for an additional 24, 48 or 72 hours. Cells were harvested and analyzed for Bax, PLSCR1, Noxa, and IFITM1 protein expression by Western blot. Membranes were stripped and reprobed for β-actin, which was used as a loading control. E2, 17β-estradiol; IFITM1, interferon induced transmembrane protein1; PLSCR1, phospholipid scramblase 1; SD, standard deviation; STAT1,2, Signal transducer and activator of transcription 1,2.