Down-Regulation of MiR-1294 is Related to Dismal Prognosis of Patients with Esophageal Squamous Cell Carcinoma through Elevating C-MYC Expression.

AIMS Changes in the expression of microRNAs (miRNAs) have been found in many cancers. This study aimed to investigate the expression of miR-1294 in patients with esophageal squamous cell carcinoma (ESCC) and its effect on prognosis. The underlying mechanism was explored as well. METHODS We examined the expression of miRNA in human ESCC cancer tissues and adjacent non-tumor controls using quantitative reverse transcription polymerase chain reaction (qRT-PCR). And the relationship between expressions of miR-1294 and ESCC prognosis was analyzed in this study. Over-expression and knock-down methods were used to investigate the biological functions of miRNA-1294. The effect of miRNA-1294 on cell proliferation was evaluated by MTT. Besides, the function of miR-1294 on cell migration and invasion were evaluated by transwell assays. RESULTS MiR-1294 was significantly down-regulated in human ESCC tissues compared with the non-tumor controls tissues (P=0.014). And patients with low miR-1294 expression had a significantly poorer prognosis than those with a high miR-1294 expression (P=0.040). Negative association was defined between the expression of miR-1294 and the c-MYC expression in ESCC patients (Pearson correlation, r=-0.299, P=0.0079). Additionally, it was found that miR-1294 suppress esophageal cancer cells proliferation, migration and invasion capacity through targeting c-MYC in vitro. CONCLUSIONS Down-regulation of miR-1294 correlates with poor prognosis of ESCC. It's partially due to the reduced function of c-MYC. This study may give insight into the understanding of pathogenesis of esophageal cancer and provide evidence for diagnosis and treatment of esophageal cancer.