title: Promoter methylation of the RGC32 gene in nonsmall cell lung cancer.
abstract: BACKGROUND
  Lung cancer is the leading cause of cancer-related deaths worldwide. Epigenetic inactivation of certain genes by aberrant promoter methylation is recognized as a crucial component in the initiation and progression of lung cancer. Response gene to complement 32 (RGC32) has been identified as a cell cycle regulator induced by activation of complements; however, its role in carcinogenesis is still controversial.
  
  
  METHODS
  The authors examined the methylation status in the promoter region of RGC32 gene in nonsmall cell lung cancers (NSCLCs) using a methylation-specific PCR and correlated the results with clinicopathological features.
  
  
  RESULTS
  RGC32 methylation was found in 45 of 173 NSCLCs (26.0%) and was related to the gene expression. RGC32 methylation was more frequent in females than in males (P<0.05). RGC32 methylation was not significantly associated with the prognosis of patients; however, when the patients were categorized by TP53 mutational status, the effect of RGC32 methylation on prognosis was significantly different between those with and without TP53 mutations (P = .005 [test for homogeneity]). Specifically, RGC32 methylation was associated with significantly worse survival in the cases with wild-type TP53, whereas it exhibited a better survival outcome in the cases with TP53 mutations.
  
  
  CONCLUSIONS
  The current findings suggest that methylation-associated down-regulation of RGC32 plays an important role in the pathogenesis of NSCLC, particularly in females. However, further studies with a large number of cases are needed to confirm the authors' findings.
authors.affiliation: Department of Anatomy, School of Medicine, Kyungpook National University, Daegu 702-422, Republic of Korea.
authors.forename: Dong Sun
authors.initials: DS
authors.lastname: Kim
authors.forename: Ji Yun
authors.initials: JY
authors.lastname: Lee
authors.forename: Su Man
authors.initials: SM
authors.lastname: Lee
authors.forename: Jin Eun
authors.initials: JE
authors.lastname: Choi
authors.forename: Sukki
authors.initials: S
authors.lastname: Cho
authors.forename: Jae Yong
authors.initials: JY
authors.lastname: Park
mesh_terms: D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics* / Q000401:mortality; D018797:Cell Cycle Proteins / Q000235:genetics*; D019175:DNA Methylation; D015536:Down-Regulation; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics* / Q000401:mortality; D008297:Male; D008875:Middle Aged; D009124:Muscle Proteins / Q000235:genetics*; D009419:Nerve Tissue Proteins / Q000235:genetics*; D011401:Promoter Regions, Genetic
chemical_list: D018797:Cell Cycle Proteins; D009124:Muscle Proteins; D009419:Nerve Tissue Proteins; C115049:RGCC protein, human