title: 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).
  
  
  METHODS
  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.
  
  
  CONCLUSIONS
  Methylation status of RARβ2 and LINE-1 was related to the development and possibly the severity of ESCC.
authors: Department of Biomedical Science and Environmental Biology, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors: Ruei-Nian
authors: RN
authors: Li
authors: Fang-Jung
authors: FJ
authors: Yu
authors: Chun-Chieh
authors: CC
authors: Wu
authors: Yu-Kuei
authors: YK
authors: Chen
authors: Chun-Chieh
authors: CC
authors: Yu
authors: Shah-Hwa
authors: SH
authors: Chou
authors: Jui-Ying
authors: JY
authors: Lee
authors: Yu-Jen
authors: YJ
authors: Cheng
authors: Ming-Tsang
authors: MT
authors: Wu
authors: I-Chen
authors: IC
authors: Wu
mesh_terms: D014408:Biomarkers, Tumor / Q000235:genetics; D002294:Carcinoma, Squamous Cell / Q000235:genetics* / Q000473:pathology / Q000628:therapy; D059248:Chemoradiotherapy; D017024:Chemotherapy, Adjuvant; D019175:DNA Methylation; D004938:Esophageal Neoplasms / Q000235:genetics* / Q000473:pathology / Q000628:therapy; D006801:Humans; D020084:Long Interspersed Nucleotide Elements / Q000235:genetics; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D018714:Radiotherapy, Adjuvant; D018168:Receptors, Retinoic Acid / Q000235:genetics*
chemical_list: D014408:Biomarkers, Tumor; D018168:Receptors, Retinoic Acid; C540966:retinoic acid receptor, beta2, human
keywords: DNA methylation; Long interspersed nuclear elements (LINE-1); esophageal squamous cell carcinoma; global hypomethylation; retinoic acid receptor beta2 (RARβ2)