Epidermal growth factor upregulates Skp2/Cks1 and p27kip1 in human extrahepatic cholangiocarcinoma cells

Figure 1 Results of immunohistochemical staining. A-C: Immunohistochemistry for (A) Skp2, (B) Cks1, and (C) Ki67 proteins showed that stains were mainly expressed in the nuclei of cancer cells; D: The staining pattern of p27^kip1 was somewhat heterogeneous. The pattern of nuclear staining was mainly noticed, and some of them were expressed as diffuse cytoplasmic staining. The staining intensity of Skp2, Cks1, and p27^kip1 was classified as follows: 0, no staining; 1, weak; 2, moderate; 3, strong. The staining pattern of Ki-67 was nuclear and classified as positive or negative. At least 20 high-power fields will be randomly chosen, and 2000 cells will be always counted. Skp2: S-phase kinase-associated protein 2; Cks1: Cyclin-dependent kinases regulatory subunit 1.