Fig. 1

CR-1 expression is significantly up-regulated in ccRCC cells and tissues and high CR-1 expression predicts poor prognosis. (A) CR-1 mRNA and protein levels (left and right panels, respectively) in 38 paired ccRCC tumor tissues (T) and adjacent non-tumor tissues (N) were analysed by qRT-PCR and Western blot, respectively, with β-actin used as the calibrator. Data are presented as box-and-whisker plot. The line inside the boxes indicates median values with the upper and lower limits corresponding to the 75th and 25th percentiles, respectively. The upper and lower horizontal whiskers denote the 95th and 5th percentiles respectively. P values were calculated using a Student’s paired t-test, ***P <  0.001. (B) Expression of CR-1 protein in 8 representative pairs of ccRCC tissues is presented. (C) CR-1 protein expression was determined in several human ccRCC cell lines (Caki-2, 786-O, 769-P, A498, and Caki-1) and human normal renal proximal tubule epithelial cell line HK-2 by Western blot. (D) CR-1 mRNA expression was detected in the HK-2 cell line and the indicated ccRCC cell lines by qRT-PCR. Data are represented as mean ± standard deviation (SD) of three individual experiments. The relative abundance of CR-1 mRNA expression in HK-2 cells was arbitrarily designated as 1. (E) Representative IHC staining images in ccRCC and adjacent non-tumor tissues. (a) Negative CR-1 staining in adjacent non-tumor tissues. (b) Weak staining of CR-1 in ccRCC tissues. (c) Strong staining of CR-1 in ccRCC tissues. Original magnification, × 400. (F) The IHC score of CR-1 in ccRCC tissues was markedly higher than that of adjacent non-tumor tissues. Data are shown as mean ± SD. ***P <  0.001 by two-sided unpaired Student’s t test. (G) CR-1 protein expression was associated with T stage, lymph-node status, distant metastasis, TNM stage and Fuhrman grade. *P <  0.05, **P < 0.01, ***P < 0.001 by Chi-square test. (H) Kaplan–Meier analysis of overall survival (OS) for all patients and recurrence-free survival (RFS) for non-metastatic patients is shown based on CR-1 expression. Left and right panels indicate OS and RFS, respectively. Log-rank test was used to calculate P values