Figure 1. Down-regulation of Skp2 protein by siRNA in PFC in vitro by immunoflurescence. Immunoflurescence staining indicated high constitutive levels of Skp2 protein (arrow indication) in the nucleolus of PFC and NFC transfected with pSuppressor vehicle (A, D) or without transfection (B, E). Transfection with Skp2 siRNA dramatically decreased the expression of Skp2 protein in PFC cells (C, F). The scale bar is equal to 40 μm.