title: Epigenetic and genetic alterations of the EDNRB gene in nasopharyngeal carcinoma.
abstract: BACKGROUND
  Loss of heterozygosity (LOH) at 13q22 is a common event in nasopharyngeal carcinoma (NPC). EDNRB gene located at 13q22 has been demonstrated to be hypermethylated in some kinds of tumors. In the current study, we focused on the epigenetic and genetic alterations of EDNRB in NPC.
  
  
  METHODS
  The mRNA expression of EDNRB was detected by semiquantitative RT-PCR and real-time quantitative PCR in 49 NPC and 12 chronic nasopharyngitis biopsies. The methylation and LOH status of EDNRB were examined by methylation-specific polymerase chain reaction, microsatellite PCR and sequencing. We also examined the mRNA expression of EDNRB in four NPC cell lines after 5-aza-2'-deoxycytidine treatment.
  
  
  RESULTS
  EDNRB was downregulated in primary NPC tissues and NPC cell lines, and a relatively higher methylation level of EDNRB was found in NPC biopsies (84%) compared to that in chronic nasopharyngitis biopsies (42%). Treatment of NPC cell lines with 5-aza-2'-deoxycytidine activated EDNRB expression. LOH of EDNRB gene was also found at two microsatellite sites with ratios of 6.25 and 16.67% in NPC.
  
  
  CONCLUSIONS
  Our results suggested that EDNRB expression may be affected by aberrant promoter methylation and gene deletion and may play a role in the development of NPC.
authors.affiliation: Cancer Research Institute, Xiang-Ya School of Medicine, Central South University, Changsha, PR China.
authors.forename: Liang
authors.initials: L
authors.lastname: Zhou
authors.forename: Xiangling
authors.initials: X
authors.lastname: Feng
authors.forename: Wenjiao
authors.initials: W
authors.lastname: Shan
authors.forename: Wen
authors.initials: W
authors.lastname: Zhou
authors.forename: Weidong
authors.initials: W
authors.lastname: Liu
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.forename: Bin
authors.initials: B
authors.lastname: Zhu
authors.forename: Hongmei
authors.initials: H
authors.lastname: Yi
authors.forename: Kaitai
authors.initials: K
authors.lastname: Yao
authors.forename: Caiping
authors.initials: C
authors.lastname: Ren
mesh_terms: D000328:Adult; D045744:Cell Line, Tumor; D002908:Chronic Disease; D015536:Down-Regulation; D044127:Epigenesis, Genetic; D005260:Female; D006801:Humans; D008297:Male; D008745:Methylation; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000235:genetics* / Q000378:metabolism; D010612:Pharyngitis / Q000235:genetics / Q000378:metabolism; D044023:Receptor, Endothelin B / Q000235:genetics* / Q000378:metabolism; D012220:Rhinitis / Q000235:genetics / Q000378:metabolism
chemical_list: D044023:Receptor, Endothelin B