MicroRNA-373 promotes the development of esophageal squamous cell carcinoma by targeting and .

INTRODUCTION

MicroRNA373 was highly expressed in many tumors including esophageal cancer. However, its molecular mechanism is still unclear, especially epigenetic modification, in esophageal squamous cell carcinoma (ESCC).

METHODS

In this study, we investigated serum levels of the miR-371-373 cluster in ESCC patients before and after surgical removal, and further focused on the expression level of miR-373-3p in tumor tissues of ESCC patients and its target genes. In addition, the epigenetic alterations of miR-373-3p promoter was analyzed.

RESULTS

The expression levels of miR-371-5p and miR-373-3p were significantly increased in preoperative serum of ESCC patients compared with that of healthy volunteers (<0.01); however, they dropped significantly after surgical removal (<0.01). Compared with adjacent normal tissues, miR-373-3p also showed significant up-regulation in cancer tissues (<0.05). The methylation levels of miR-373-3p promoter were 42.86% in ESCC cancer tissue and 66.67% in adjacent normal tissues. The low methylation of the miR-373-3p promoter may promote the expression of miR-373-3p. () and () are predicted to be targets of miR-373-3p by the bioinformatics method. They are the genes in the Hippo and the 53 signaling pathway, respectively. Their respective upstream genes, and , and the downstream genes, and , were also detected. The expression of all these genes were significantly decreased in ESCC cancer tissues compared with adjacent normal tissues.

CONCLUSIONS

This study shows that DNA epigenetic modification in the miR-373-3p promoter region and the Hippo and 53 signaling pathways play important roles during the miR-373-3p mediating ESCC development process.