FITC-conjugated Insulin uptake by MCF-7 following Sirt7 inhibition. A) Representative image for FITC-conjugated Insulin uptake by MCF-7 transfected with either mock or Sirt7 siRNA vectors. Stably transfectcted MCF-7 cells were cultured in chamber slides in 0.1% FBS containing medium overnight. Cells were then incubated with FITC-conjugated Insulin (0 and 1000 nM) for 2 hours and then washed, fixed and analyzed by Leica confocal microscope. Nucleus was counterstained with DAPI (blue) while cytoplasm was counterstained with Rhodamine Phalloidin (red); B) Insulin uptake by MCF-7 Mock transfected and incubated with different FITC-labeled insulin for different time intervals; and C) Insulin uptake by MCF-7 cells transfected with Sirt7 siRNA.