Increased expression of miR-21 predicts poor prognosis in patients with hepatocellular carcinoma

Background: MicroRNAs (miRNAs) play critical roles in hepatocellular carcinoma (HCC) development and progression. Aberrant miR-21 expression has been reported in several cancers. However, the clinical significance of miR-21 in human HCC is still unclear. Methods: A total of 112 patients with primary HCC who underwent a curative liver resection were included in this retrospective study. The differentially expressed amount of the miR-21 was validated by quantitative real-time PCR (qRT-PCR). Survival rate was analyzed by log-rank test, and survival curves were plotted according to Kaplan-Meier. Multivariate analysis of the prognostic factors was performed with Cox regression model. Results: As revealed by qRT-PCR analysis, miR-21 expression was significantly upregulated in HCC tissues when compared with adjacent non-tumor tissues (P<0.05). High miR-21 expression level was observed to be closely correlated with tumor differentiation, TNM stage and vein invasion (P<0.05). Patients who had high miR-21 expression had a shorter overall survival than patients who had low miR-21 expression (P<0.05). Moreover, multi-variate analysis of the prognosis factors with a Cox proportional hazards model showed that high miR-21 expression was a significant independent predictor of poor survival in HCC (P<0.05). Conclusion: Our results suggested that increased expression of miR-21 was significantly correlated with tumor progression and could be a novel potential biomarker for HCC prognosis.