Decreased expression of miR-126 correlates with metastatic recurrence of hepatocellular carcinoma

The liver transplant (LT) situation represents an attractive model for studying hepatocellular carcinoma (HCC) metastasis. Based on microarray data, we previously found that miR-126 expression was lower in tumor tissues of patients with post-LT HCC recurrence compared with non-recurrence. In this study, we examined the expression of miR-126 in HCC samples from 68 patients who had undergone LT using quantitative real-time PCR and analyzed its correlation with clinicopathological features and prognosis of patients. Furthermore, we performed experimental analyses to explore the involvement of miR-126 in HCC metastasis. We found that miR-126 levels were lower in tumor tissues of patients with post-LT HCC recurrence in comparison to patients with no-recurrence (p = 0.009). Lower expression of miR-126 in HCC was associated significantly with tumor recurrence (p = 0.011) and poor survival (p = 0.009) of patients. Functional studies indicated that ectopic expression of miR-126 significantly inhibits HCC cells migration, invasion, proliferation and colony formation in vitro, and suppresses experimental lung colonization in vivo. Our study revealed that down-regulation of miR-126 plays an important role in HCC metastasis, and suggest a potential application of miR-126 in prognosis prediction and HCC treatment.