MiR-630 inhibits invasion and metastasis in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is among the most aggressive malignancies and has a high incidence in China. MicroRNAs (miRNAs) are small endogenous RNAs that regulate multiple tumorigenic processes, including proliferation, invasion, metastasis and prognosis. Using miRNA expression profiling analysis, we found that miR-630 was markedly down-regulated in three ESCC tissue samples compared with that in paired normal esophageal tissues. Differential miR-630 expression was subsequently confirmed using quantitative real-time PCR. To determine whether miR-630 down-regulation could be considered as a diagnostic indicator and adverse prognostic factor, we investigated the association between miR-630 and clinicopathological characteristics in patients with ESCC. It was found that decreased miR-630 expression was associated with poor overall survival in these patients. In addition, we also explored the biological function of miR-630 by targeting Slug and investigated the correlation between miR-630 expression and epithelial-mesenchymal transition (EMT) progression in vivo and in vitro. Ectopic miR-630 expression could inhibit proliferation, invasion and metastasis, whereas miR-630 knockdown induced proliferation, invasion, metastasis and EMT traits. Overall, our study supports a role for miR-630 as a critical novel modulator in ESCC.