title: [Expression and implication of base excision repair genes in human nasopharyngeal carcinoma and non-tumor nasopharyngeal tissues].
abstract: OBJECTIVE
  Base excision repair (BER) genes play important roles in maintaining genomic stability and their abnormal expression are associated with several cancers. This study was to investigate the expression of 7 important BER genes (hOGG1, ADPRT, APE1, MBD4, POLB, XRCC1 and LIG3) in nasopharyngeal carcinoma (NPC) and non-tumor nasopharyngeal tissues, and evaluate their clinical significance.
  
  
  METHODS
  The expression of hOGG1, ADPRT, APE1, MBD4, POLB, XRCC1 and LIG3 in 24 specimens of NPC and 24 specimens of non-tumor nasopharyngeal tissues was detected by reverse transcription-polymerase chain reaction (RT-PCR). The differential expression of hOGG1 and ADPRT was further detected by immunohistochemistry in 99 specimens of NPC and 28 specimens of non-tumor nasopharyngeal tissues.
  
  
  RESULTS
  hOGG1, ADPRT, APE1, MBD4, POLB, XRCC1 and LIG3 were expressed in both NPC and non-tumor nasopharyngeal tissues. Among them, the mRNA levels of hOGG1 and ADPRT were significantly lower in NPC than in non-tumor nasopharyngeal tissues (P<0.001). The protein levels of hOGG1 and ADPRT in NPC were also reduced. The high expression rates of hOGG1 were 50.5% in NPC and and 92.8% in non-tumor nasopharyngeal tissues (P<0.001), and those of ADPRT were 53.5% and 96.4%, respectively (P<0.001). However, the expression levels of hOGG1 and ADPRT had no correlations to the clinical stage and prognosis of NPC.
  
  
  CONCLUSIONS
  The decreased expression of hOGG1 and ADPRT might be closely related to the development of nasopharyngeal carcinoma.
authors.affiliation: State Key Laboratory of Oncology in South China, Guangzhou, Guangdong, 510060, P. R. China.
authors.forename: Na
authors.initials: N
authors.lastname: Liu
authors.forename: Xin-Xi
authors.initials: XX
authors.lastname: Zhou
authors.forename: Li-Xia
authors.initials: LX
authors.lastname: Lu
mesh_terms: D036002:ADP Ribose Transferases / Q000032:analysis / Q000235:genetics*; D000328:Adult; D000368:Aged; D045647:DNA Glycosylases / Q000032:analysis / Q000235:genetics*; D004260:DNA Repair / Q000235:genetics*; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase / Q000235:genetics; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000235:genetics*; D009305:Nasopharynx / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis
chemical_list: D012333:RNA, Messenger; D036002:ADP Ribose Transferases; D045647:DNA Glycosylases; C479058:oxoguanine glycosylase 1, human; C085108:APEX1 protein, human; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase