title: [Association between the expression and methylation of energy-related genes with Helicobacter pylori infection in gastric cancer].
abstract: OBJECTIVE
  To explore the association between the Helicobacter pylori (H. pylori) infection and the expression and methylation of energy-related genes in gastric cancer.
  
  
  METHODS
  Real-time fluorescence quantitative reverse transcription (RT)-PCR was performed to quantify the expressions level of lactate dehydrogenase (LDH), dihydrolipoamide dehydrogenase (DLD) and Ran-specific GTPase-activating protein (RanGAP) genes in the samples of human gastric cancer (n = 30), metastatic lymph node (n = 30) and peri-cancerous tissues (n = 30) as confirmed by pathological examinations. Those patients were chosen of Affiliated Hospital of Guiyang Medical University, from January 2005 to December 2009. The relationship between the gene expression and H. pylori infection was analyzed. The methylation of LDH, DLD and RanGAP genes at promoter CpG island was measured by bisulfite sequencing (BSP).
  
  
  RESULTS
  The relative gene expressions of LDH, DLD and RanGAP in peri-cancerous tissues, gastric cancer and metastatic lymph nodes were 1.0, 3.1, 3.0 and 1.0, 3.1, 2.8, and 1.0, 0.4, 0.5 respectively (all P < 0.05). The expression levels of LDH and DLD genes in H. pylori-positive gastric cancer was high than those in the negative group (2.3 vs 1.0, 3.0 vs 1.0, 2.6 vs 1.0, all P < 0.05). The demethylation of LDH and DLD genes at promoter -2325 and -1885 site as well as the over methylation of RanGAP gene at the promoter -570 and -170 sites respectively were detected in H. pylori infection and cagA-overexpressed cells.
  
  
  CONCLUSIONS
  H. pylori infection may promote the development and progression of gastric cancer by inducing the aberrant methylation of LDH, DLD and RanGAP genes to up-regulate the gene expressions of LDH and DLD and down-regulate the gene expression of RanGAP.
authors.affiliation: Guiyang Medical University, Guiyang, China.
authors.forename: Wen-jie
authors.initials: WJ
authors.lastname: Xu
authors.forename: Jian-jiang
authors.initials: JJ
authors.lastname: Zhou
authors.forename: Yuan
authors.initials: Y
authors.lastname: Xie
authors.forename: Wen-ling
authors.initials: WL
authors.lastname: Wang
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhao
authors.forename: Xian
authors.initials: X
authors.lastname: Chen
authors.forename: Yi
authors.initials: Y
authors.lastname: Li
mesh_terms: D000328:Adult; D000368:Aged; D018899:CpG Islands; D019175:DNA Methylation; D008058:Dihydrolipoamide Dehydrogenase / Q000235:genetics / Q000378:metabolism; D005260:Female; D020690:GTPase-Activating Proteins / Q000235:genetics / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic; D016481:Helicobacter Infections / Q000235:genetics* / Q000378:metabolism; D016480:Helicobacter pylori; D054884:Host-Pathogen Interactions; D006801:Humans; D045022:Lactate Dehydrogenases / Q000235:genetics / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D013274:Stomach Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000382:microbiology*; D024363:Transcription Initiation Site
chemical_list: D020690:GTPase-Activating Proteins; D045022:Lactate Dehydrogenases; D008058:Dihydrolipoamide Dehydrogenase