Therefore, we also performed immunohistochemical staining of tissue arrays

containing tissue sections from 40 HCC and 40 liver tissues (normal) using a polyclonal antibody specific to DKK4. DKK4 staining intensity was classified on a 0-to-3 scale: 0, negative; 1+, weak; 1+ to 2+, moderate; 3+, strong. Of the 40 HCC samples, 12 (30%) were negative, 10 (25%) stained weakly, 14 (35%) stained PS 341 moderately, and 4 (10%) stained strongly. In the 40 normal liver tissues, 13 (32.5%) stained moderately and 27 (67.5%) stained strongly. DKK4 staining was observed mainly in the cytoplasm of normal cells but was barely detected in tumor tissues (Fig. 3B). Three representative paired specimens are shown in Fig. 3C. The expression of TR was also analyzed. Of the 40 HCC samples, 15 (37.5%) were negative, 10 (25%) stained weakly, 12 (30%) stained moderately, and 3 (7.5%) stained strongly. In the 40 normal liver tissues, 24 (60%) stained moderately and 16 (40%) stained strongly. The correlation between TR and DKK4 buy Apitolisib expression was analyzed. Because of the nonparametric nature of these data, Spearman’s rank correlations were also calculated. TR and DKK4 expression levels were positively correlated in both normal tissues (Pearson correlation

coefficient = 0.517, P = 0.001; Spearman’s rank correlation coefficient = 0.464, P = 0.003) and cancerous tissues (Pearson correlation coefficient = 0.530, P < 0.001; Spearman's rank correlation coefficient = 0.553, P < 0.001). Regression analyses were performed to identify the clinical factors associated with the tumor/normal (T/N) ratio of DKK4 in HCC after surgical resection. The T/N ratio of DKK4 expression learn more in HCC samples correlated with tumor size (beta

= −0.050; 95% CI = −0.095 to −0.006; P = 0.027), histological grade (beta = −0.703; 95% CI = −1.024 to −0.382; P < 0.001), and liver cirrhosis (beta = 0.546; 95% CI = 0.119 to 0.972; P = 0.013). Patients were dichotomized into two groups based on higher and lower T/N ratios of DKK4 expression. Kaplan-Meier analyses showed that patients with a T/N ratio of DKK4 expression >0.75 had a longer disease-free survival than did those with a lower T/N ratio. The mean disease-free survival periods for higher and lower T/N groups were 52.3 months (95% CI = 37.4-67.3 months) and 28.7 months (95% CI = 18.8-38.6 months), respectively (P = 0.010) (Fig. 3D). Additionally, the mean overall survival period was longer in the higher-expression group (110.1 months; 95% CI = 97.5-112.7 months) than in the lower-expression group (78.5 months; 95% CI = 64.2-92.9 months; P = 0.008) (Fig. 3E). Figure 3D,E illustrates the cumulative survival curves of patients subgrouped according to lower and higher expression of DKK4 in HCC tissues. DKK4 is a Wnt antagonist protein involved in the Wnt signaling pathway.