Fig. 1

The clinical significance of elevated CD56 expression in ccRCC tissues and cell lines. A Immunohistochemical (IHC) analysis of CD56 expression in normal renal tissues (n = 16) and different grades of clear cell RCC specimens (n = 40). Low grade represents grade I plus grade II and high grade represents grade III plus grade IV. Representative images of CD56 immunohistochemical staining. B Protein expression profile of CD56 in normal renal tissues (n = 84) and primary clear cell RCC tissues (n = 110). C The clinical samples were collected from six patients, and the expression levels of CD56 were measured by using western blot. D Real-Time qPCR was conducted to determine the mRNA expression of NCAM1 in ccRCC tissues and their paired adjacent normal tissues (n = 6). E Western blot was conducted to examine the protein expression of CD56 in HK-2, Caki-1, 786-O and A-498 cells. GAPDH was used as a loading control. Each experiment was repeated at least three times. F Real-time qPCR was used to measure the mRNA expression of NCAM1 in the human ccRCC cell lines (Caki-1, 786-O and A-498) and human normal renal epithelial cell line (HK-2). G The differential expression of NCAM1 in ccRCC and normal tissues by TCGA and GEO databases. H Survival curves suggested that patients with elevated NCAM1 mRNA level showed poorer overall survival (OS) in ccRCC patients. All values represented the mean ± SD of three independent experiments. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001 by one-way ANOVA (A, E, F), unpaired two-tailed Student’s t test (B), paired two-tailed Student’s t test (D), or log-rank test (H)