title: Expression and DNA methylation status of the Rap2B gene in human bronchial epithelial cells treated by cigarette smoke condensate.
abstract: BACKGROUND
  The relationship between lung cancer and smoking has been demonstrated. The Rap2B gene is usually overexpressed in lung cancers. This study was aimed to investigate the Rap2B gene expression and its promoter methylation in human bronchial epithelial cells (16HBE) treated by cigarette smoke condensate (CSC).
  
  
  METHODS
  16HBE cells were treated with CSC (1/8 IC50). Soft ager assay, tumorigenicity test, chromosome aberrations analysis were used to identify the transformed cells. The expression level of mRNA and protein of Rap2B was detected using real time PCR and Western blotting, respectively. The genome DNA methylation level was detected using combined bisulfite restriction analysis (COBRA) and the methylation status of the target fragment in Rap2B gene promoter was determined by bisulfite sequencing PCR (BSP).
  
  
  RESULTS
  The 16HBE cells were successfully malignant transformed after the chronic exposure to CSC. The expression of Rap2B gradually increased in the process of malignant transformation. Meanwhile, global DNA was hypomethylated. However, no obvious change was observed in the methylation level of Rap2B gene promoter in transformed 16HBE cells.
  
  
  CONCLUSIONS
  Rap2B gene may play an important role in the process of lung cancer and global DNA hypomethylation might be an early event in tumorigenesis.
authors: a School of Public Health, Medical College, Wuhan University of Science and Technology , Wuhan , China .
authors: Shuangling
authors: S
authors: Zhang
authors: b Public Health College of Zhengzhou University , Zhengzhou , China .|c Changsha Center of Supervision & Inspection on Food Quality Safety , Changsha , China .
authors: Ming
authors: M
authors: Zhou
authors: a School of Public Health, Medical College, Wuhan University of Science and Technology , Wuhan , China .
authors: Gaofeng
authors: G
authors: Jiang
authors: d Shenzhen Center for Chronic Disease Control and Prevention , Shenzhen , China , and.
authors: Chunmei
authors: C
authors: Gong
authors: e Shenzhen Center for Disease Control and Prevention , Shenzhen , China.
authors: Dong
authors: D
authors: Cui
authors: e Shenzhen Center for Disease Control and Prevention , Shenzhen , China.
authors: Lingfeng
authors: L
authors: Luo
authors: e Shenzhen Center for Disease Control and Prevention , Shenzhen , China.
authors: Desheng
authors: D
authors: Wu
authors: e Shenzhen Center for Disease Control and Prevention , Shenzhen , China.
authors: Haiyan
authors: H
authors: Huang
authors: b Public Health College of Zhengzhou University , Zhengzhou , China .
authors: Qiao
authors: Q
authors: Zhang
authors: e Shenzhen Center for Disease Control and Prevention , Shenzhen , China.
authors: Linqing
authors: L
authors: Yang
mesh_terms: D001980:Bronchi / Q000166:cytology; D002460:Cell Line; D002471:Cell Transformation, Neoplastic; D019175:DNA Methylation / Q000187:drug effects*; D004847:Epithelial Cells / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D011401:Promoter Regions, Genetic; D012906:Smoke / Q000009:adverse effects*; D014026:Nicotiana; D020668:rap GTP-Binding Proteins / Q000235:genetics* / Q000378:metabolism
chemical_list: D012906:Smoke; C065562:RAP2B protein, human; D020668:rap GTP-Binding Proteins
keywords: Cigarette smoke condensate; DNA methylation; Rap2B gene; lung cancer