title: Rationales for expression and altered expression of apoptotic protease activating factor-1 gene in gastric cancer.
abstract: OBJECTIVE
  To elucidate the relationship between apoptotic protease activating factor-1 (Apaf-1) gene and gastric cancer.
  
  
  METHODS
  Thirty-five postoperative cancer and adjacent normal tissue samples were collected in the present study. Expression of the Apaf-1 gene in these samples was analyzed by semi-quantitative RT-PCR. Loss of heterozygosity (LOH) was used to determine whether there was loss of Apaf-1 gene in domain of 12q22-23 in the samples. Promoter methylation of Apaf-1 gene in the samples was analyzed by methylation specific (MSP) PCR.
  
  
  RESULTS
  The expression of Apaf-1 mRNA in gastric cancer tissue samples was 51%. The LOH frequency of D12S346, D12S1706, D12S327, D12S1657 and D12S393 was 33%, 8%, 58%, 12% and 42%, respectively. Fifty percent LOH was found at two sites and 17% LOH at three sites. Apaf-1 mRNA expression decreased significantly in 13 cases (rs=0.487, P=0.003). The rate of Apaf-1 promoter methylation was 49% in gastric cancer tissue samples and 23% in para-cancerous tissue samples. Promoter methylation occurred significantly in 16 of 18 gastric cancer tissue samples with decreased expression of Apaf-1 mRNA rs=0.886, P=10(-6)).
  
  
  CONCLUSIONS
  The expression of Apaf-1 gene is low in gastric cancer tissues. Methylation of Apaf-1 gene promoter and LOH in domain of 12q22-23 are the main reasons for the expression and altered expression of Apaf-1 gene.
authors: Department of Gastroenterology, Shengjing Hospital Affiliated to China Medical University, Shenyang110004, Liaoning Province, China.
authors: He-Ling
authors: HL
authors: Wang
authors: Han
authors: H
authors: Bai
authors: Yan
authors: Y
authors: Li
authors: Jun
authors: J
authors: Sun
authors: Xue-Qing
authors: XQ
authors: Wang
mesh_terms: D000368:Aged; D053477:Apoptotic Protease-Activating Factor 1 / Q000235:genetics / Q000378:metabolism*; D016022:Case-Control Studies; D019175:DNA Methylation; D004273:DNA, Neoplasm / Q000235:genetics / Q000378:metabolism; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D019656:Loss of Heterozygosity / Q000235:genetics; D008297:Male; D008875:Middle Aged; D011401:Promoter Regions, Genetic / Q000235:genetics; D013274:Stomach Neoplasms / Q000235:genetics / Q000378:metabolism*
chemical_list: C506592:APAF1 protein, human; D053477:Apoptotic Protease-Activating Factor 1; D004273:DNA, Neoplasm