CircRNA CircRIMS is Overexpressed in Esophageal Squamous Cell Carcinoma and Downregulate miR-613 through Methylation to Increase Cell Proliferation

Background: Esophageal squamous cell carcinoma (ESCC) as the most common subtype of esophageal cancer accounts for about 95% of all cases. CircRNA CircRIMS has been characterized as an oncogenic circRNA in gastric cancer, while its role in other cancers is unknown. This study aimed to explore the role of CircRIMS in esophageal squamous cell carcinoma (ESCC). MethodsTissues collected from 60 ESCC patients were used in this study. The expression of CircRIMS and miR-613 were detected by RT-qPCRs. The 60 ESCC patients were followed up for 5 years to evaluate the prognostic value of CircRIMS for ESCC. The role of CircRIMS in regulating the expression of miR-613 and methylation was assess by overexpression experiments and RT-qPCRs. The role of CircRIMS and miR-613 in regulating cell proliferation was analyzed by BrdU assay. ResultsWe found that CircRIMS was overexpressed in ESCC and predicted poor survival. In addition, miR-613 was downregulated in ESCC and inversely correlated with CircRIMS. In ESCC cells, overexpression of CircRIMS decreased the expression levels of miR-613 and increased the methylation of miR-613 gene. Cell proliferation assay showed that overexpression of CircRIMS reduced the inhibitory effects of overexpression of miR-613 on cell proliferation. ConclusionsCircRIMS may downregulate miR-613 through methylation to increase cell proliferation in ESCC.