Association of microRNA 21 With Biological Features and Prognosis of Neuroblastoma.

BACKGROUND The aim of this study was to assess the differences in microRNA 21 expression among neuroblastoma (NB), embryonic tissue, and normal adrenal tissue and to identify correlations between microRNA 21 expression, the biological features of the tumor, and prognosis. METHODS A total of 70 patients with NB were selected from December 2005 and December 2007. Real-time polymerase chain reaction was used to assess microRNA 21 expression. All patients were followed-up for 5 years. RESULTS Significant differences in microRNA 21 expression were found between the 3 groups, with the highest expression in the NB samples (P < .001). The expression of microRNA 21 was highest in the high-risk group compared with the moderate- and low-risk groups (P < .001). The microRNA 21 expression in the MYCN amplification group was higher than in the group without amplification (P = .001). The 5-year overall survival rate of patients with NB was 71.4%. CONCLUSIONS The higher expression of microRNA 21 in NB samples compared with embryonic and normal tissue samples predicted a close correlation between microRNA 21 expression and the biological features of NB. In patients with NB, higher microRNA 21 expression correlated with lower rates of overall survival. Therefore, microRNA 21 expression may represent a novel risk factor for determining the prognosis of patients with NB.