title: Identification of hypermethylation in hepatocyte cell adhesion molecule gene promoter region in bladder carcinoma.
abstract: BACKGROUND
  Epigenetic regulation such as aberrant hypermethylation of CpG islands in promoter plays a key role in tumorigenesis. 5-Aza-2'-deoxycytidine (5-aza-CdR) which is a potent inhibitor of DNA methylation can reverse the abnormal hypermethylation of the silenced tumor suppressor genes (TSGs). It has been reported that hepatocyte cell adhesion molecule (hepaCAM) acts as a tumor suppressor gene and expression of its mRNA and protein were down-regulated in bladder cancer. Over-expression of hepaCAM can inhibit cancer growth and arrest renal cancer cells at G0/G1 phase. In this study, we investigated the methylation status of hepaCAM gene, as well as the influence of 5-aza-CdR on expression of hepaCAM gene in bladder cancer cells.
  
  
  METHODS
  CpG islands in hepaCAM promoter and methprimers were predicted and designed using bioinformatics program. Methylation status of hepaCAM promoter was evaluated in bladder cancer tissues and two cell lines (T24 and BIU-87) by Methylation-specific PCR; Western blot and Immunofluorescence were used to detect expression of hepaCAM protein after 5-aza-CdR treatment; Flow cytometry assay was performed to determine effectiveness of 5-aza-CdR on cell cycle profile.
  
  
  RESULTS
  CpG island in promoter of hepaCAM gene was hyper-methylated both in bladder carcinoma tissues and cell lines (T24 and BIU-87). Otherwise, aberrant methylation of its promoter was associated with its decreased expression. Hypermethylation of hepaCAM gene was reversed and expression of its mRNA and protein were re-activated in two cell lines by DNA methyltransferases inhibitor 5-aza-CdR. Flow cytometry assay demonstrated that 5-aza-CdR can inhibit growth of cancer cells by arresting cancer cells at G0/G1 phase.
  
  
  CONCLUSIONS
  Abnormal hypermethylation in CpG island of hepaCAM promoter is involved in absence of hepaCAM gene expression when bladder cancer occurs. Re-activation of hepaCAM gene by 5-aza-CdR can inhibit growth of cancer cells and arrest cells at G0/G1 phase.
authors: 1. Department of Laboratory Diagnosis, Chongqing Medical University, Chongqing, 400016 China;
authors: Jia
authors: J
authors: Tao
authors: Qi
authors: Q
authors: Liu
authors: Xiaohou
authors: X
authors: Wu
authors: Xin
authors: X
authors: Xu
authors: Yanyi
authors: Y
authors: Zhang
authors: Qiuju
authors: Q
authors: Wang
authors: Chunli
authors: C
authors: Luo
mesh_terms: D001374:Azacitidine / Q000031:analogs & derivatives / Q000494:pharmacology; D001483:Base Sequence; D002453:Cell Cycle / Q000187:drug effects; D018797:Cell Cycle Proteins; D045744:Cell Line, Tumor; D018899:CpG Islands; D019175:DNA Methylation; D017931:DNA Primers; D000077209:Decitabine; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D006801:Humans; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D011506:Proteins / Q000235:genetics*; D001749:Urinary Bladder Neoplasms / Q000235:genetics* / Q000473:pathology
chemical_list: D018797:Cell Cycle Proteins; D017931:DNA Primers; C487620:HEPACAM protein, human; D011506:Proteins; D000077209:Decitabine; D001374:Azacitidine
keywords: 5-aza-CdR; Bladder carcinoma.; hepaCAM; methylation; promoter