Methylation status of retinoic acid receptor beta2 promoter and global DNA in esophageal squamous cell carcinoma
Abstract
Background
Focal hypermethylation in promoter regions of tumor suppressor genes against the background of global hypomethylation is a landmark of carcinogenesis. This study aimed to investigate the methylation status of retinoic acid receptor beta2 (RARβ2) and long interspersed nuclear elements (LINE-1) in different stages of esophageal squamous cell carcinoma (ESCC).
Method
The tumor and adjacent normal esophageal tissues from 125 male ESCC patients who underwent primary surgery were analyzed for the methylation status of RARβ2 promoter and LINE-1 through methylation-specific polymerase chain reaction and pyrosequencing.
Results
RARβ2 hypermethylation was detected in 20% of the tumor samples, but not in the normal counterparts. The methylation frequency of LINE-1 was significantly lower in the tumor than in the normal parts (median: 67.7% vs. 80%, P < 0.0005). Ninety-eight patients (78.4%) had both RARβ2 hypermethylation and LINE-1 hypomethylation or either one. There was a trend toward higher risk of advanced T stage (P for trend = 0.05) or lymph node metastasis (P for trend = 0.02) when more adverse gene methylation profiles were present.
Conclusion
Methylation status of RARβ2 and LINE-1 was related to the development and possibly the severity of ESCC. J. Surg. Oncol. 2014 109:623–627. © 2014 Wiley Periodicals, Inc.
