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

Abstract

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.