The expression and the diagnostic value of NOD2 in hepatocellular carcinoma

Abstract

Objective To investigate the expression of nucleotide-binding oligomerization domain protein 2 (NOD2) in serum of patients with hepatocellular carcinoma (HCC), and to analyse the roles of NOD2 in HCC development and its clinical diagnostic value. Methods This study including 66 patients with HCC in the hospital from March 1, 2013 to December 31, 2014 and 61 healthy controls. Serum NOD2 levels were determined by enzyme-linked immunosorbent assay (ELISA). Analysis of significance was performed with rank sum test using SPSS statistical 16.0 software. Results Serum levels of NOD2 in HCC patients were 171 pg/ml, significantly higher than that of healthy controls(95 pg/ml, Z=-5.00, P=0.00), and the serum NOD2 levels were correlated with clinical stage of HCC (H=56.26, P=0.00). Compared with the serum NOD2 levels in stage Ⅰ, Ⅱ patients (106 pg/ml) and healthy controls (95 pg/ml), the serum NOD2 level in stage Ⅲ and Ⅳ (220 pg/ml) were significantly increased (χ2=31.24, P=0.00; χ2=47.23, P=0.00), but the expression of NOD2 in stage Ⅰ and Ⅱ were nearly equal to that of the healthy controls (χ2=0.36, P=0.83). The ROC analysis revealed that the best diagnostic cutoff-point of serum NOD2 levels for predicting the Ⅲ and Ⅳ stages of HCC was 148.78 pg/ml, meanwhile corresponding sensitivity was 89.1% and specificity was 77.0%. Additionally, correlation analysis demonstrated that there was no significant correlation between NOD2 and alpha-fetal protein (r=0.44, P=0.14). Survival curves obtained that the survival time of HCC patients with NOD2 serum concentrations ≥ 200 pg/ml was significantly less than that < 200 pg/ml (χ2=15.32, P<0.05). Conclusion NOD2 is highly expressed in the serum of HCC patients, especially in advanced patients, which is possibly involved in the development of HCC and has the potential to become an effective marker used for HCC diagnosis. Key words: Liver neoplasms; Diagnosis; Alpha fetoproteins; Nucleotide-binding oligomerization domain protein 2