Downregulation of Potential Tumor Suppressor miR-203a by Promoter Methylation Contributes to the Invasiveness of Gastric Cardia Adenocarcinoma

ABSTRACT

Like many tumor suppressor genes, some miRNA genes harboring CpG islands undergo methylation-mediated silencing. In the study, we found significant downregulation and proximal promoter methylation of miR-203a and miR-203b in gastric cardia adenocarcinoma (GCA) tissues. The methylation status of miR-203a and miR-203b in tumor tissues was negatively correlated with their expression level. GCA patients in stage III and IV with reduced expression or hypermethylation of miR-203a demonstrated poor patient survival. In all, miR-203a and miR-203b may function as tumor suppressive miRNAs, and reactivation of miR-203a may have therapeutic potential and may be used as prognostic marker for GCA patients.

KEYWORDS:

• gastric cardia adenocarcinoma
• miR-203a
• miR-203b
• expression
• methylation

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the article.

Supported by grants from the National Natural Science Foundation (No. 81472335).

Acknowledgments

We thank the patients for taking part in this study.