NDRG2 down-regulation and CD24 up-regulation promote tumor aggravation and poor survival in patients with gallbladder carcinoma

Recent studies have demonstrated that N-Myc downstream-regulated gene 2 (NDRG2) may reduce the metastatic potential of breast cancer and hepatocellular carcinoma cells by regulating the expression of CD24, which is expressed in a large variety of solid tumors. The aim of this study was to clarify the clinical value of NDRG2 and CD24 expression in primary gallbladder carcinoma (GBC). One hundred and thirty GBC tissues were evaluated by immunohistochemistry for NDRG2 and CD24 expression. The associations of NDRG2 and CD24 expression with the clinicopathological characteristics and the overall survival of patients with GBC were analyzed. NDRG2 and CD24 were positively expressed in 49/130 (37.69%) and 107/130 (82.31%) of GBC tissues, respectively. In addition, the tumors with the down-regulation of NDRG2 and the up-regulation of CD24 more frequently had lymph node metastasis and lymphovascular invasion. Moreover, the tumors with the down-regulation of NDRG2 and the up-regulation of CD24 tended to show deeper invasion depth and higher TNM stage. There was a negative correlation between NDRG2 expression and CD24 expression in GBC tissues (r = -0.86, P<0.001). The patients with NDRG2 negative expression correlated with poor prognosis of GBC (P = 0.01), as opposed to CD24 (P = 0.01). The survival rate of the patients with NDRG2-/CD24+ expression was the lowest (P<0.001), and conjoined expression of NDRG2-/CD24+ was an independent prognostic indicator of GBC (P = 0.003). Our data suggest that NDRG2 down-regulation or CD24 up-regulation is an important feature of GBC. A combined detection of NDRG2/CD24 co-expression may benefit us in prediction of the prognosis in GBC.