Gastric Cancer
Copyright ©2007 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Oct 14, 2007; 13(38): 5060-5064
Published online Oct 14, 2007. doi: 10.3748/wjg.v13.i38.5060
Rationales for expression and altered expression of apoptotic protease activating factor-1 gene in gastric cancer
He-Ling Wang, Han Bai, Yan Li, Jun Sun, Xue-Qing Wang
He-Ling Wang, Yan Li, Jun Sun, Xue-Qing Wang, Department of Gastroenterology, Shengjing Hospital Affiliated to China Medical University, Shenyang 110004, Liaoning Province, China
Han Bai, Department of Infectious Diseases, Shengjing Hospital Affiliated to China Medical University, Shengyang 110004, Liaoning Province, China
Author contributions: All authors contributed equally to the work.
Correspondence to: Yan Li, Department of Gastroenterology, Shengjing Hospital Affiliated to China Medical University, Shenyang110004, Liaoning Province, China. yanli0227@126.com
Telephone: +86-24-83956986 Fax: +86-24-23582697
Received: May 20, 2007
Revised: June 18, 2007
Accepted: June 26, 2007
Published online: October 14, 2007
Abstract

AIM: 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).

CONCLUSION: 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.

Keywords: Gastric cancer, Apaf-1 gene, Loss of heterozygosity, Methylation