MiR203 Lost Suppressor Genes Function in the Process of Barrett’s Esophagus Carcinogenesis Because of High Methylation in Promoter

Abstract

This study was designed to explore the role of MiR203 promoter methylation in the process of Barrett's esophagus carcinogenesis. RT-PCR was used to detect the expression levels of miRNA-203 in Barrett's esophagus, esophageal cancer and normal esophageal mucosa cell lines, before and after the treatment of demethylation. MiR203 promoter methylation levels in these cell lines were measured by Methylation Specific PCR (MSP). Immunohistochemistry was used to test the expression and distribution of K-Ras, a target of miR203, in esophageal cancer, BE and normal esophagus tissues. The following results were found based on the above methods. MiR203 expression levels were reduced obviously in Barrett esophagus and esophageal cancer cells than normal esophageal cells, the difference was statistically significant (P=0.003). After demethylation treatment, miR203 expression levels were significantly increased in Barrett's esophagus and esophageal cancer cells, the differences were statistically significant (P=0.03). MSP results showed that miR203 promoter changed to be low-methylation or non-methylation after demethylation treatment. In conclusion, MiR203 in Barrett's esophagus and esophageal cancer cells reduced expression is related to its Promoter methylation, miR203 promoter methylation throughout the carcinogenesis of Barrett's esophagus, it may become a key molecular biomarker in process of Barrett esophagus cancerous, and may become the prevention and treatment targets of Barrett esophagus carcinogenesis.