Figure 2. Downregulation of S phase-kinase-interacting protein 2 protein by small interfering ribonucleic acid in rabbit len epithelial cells in vitro. Immunocytochemistry staining (one representative of three experiments) indicated high constitutive levels of Skp2 protein (indicated by arrow) in the nucleolus of rLECs transfected with pSuppressor vehicle (B) or without transfection (C). Transfection with Skp2 siRNA dramatically decreased the expression of Skp2 protein in rLECs (A). Scale bar is equal to 40 μm. After 48 h of transfection and 2 weeks of treatment with G418, several stable transfectant cells were cloned. Western blot analysis (one representative of three experiments) showed that high constitutive Skp2 expression can be detected in rLECs of the vehicle control group and blank control group (D). However, little expression of Skp2 was detected in the experimental group, indicating transfection with Skp2 siRNA can inhibit expression of Skp2 in rLECs in vitro (D). GAPDH served as loading control.