DNA hypermethylation of sirtuin 1 (SIRT1) caused by betel quid chewing-a possible predictive biomarker for malignant transformation.

Our results suggest that DNA hypermethylation of SIRT1 is involved in the occurrence of oral cancer in BQ chewing patients and that hypermethylation in the oral mucosa of BQ chewers could be a predictive marker for the occurrence of malignant transformation. This is the first report that showed DNA hypermethylation in clinically healthy oral epithelium of BQ chewers. Our study shows evidence that DNA hypermethylation may be an early event of oral carcinogenesis prior to observable clinical changes.