Hypermethylation and aberrant expression of Wnt antagonist secreted frizzled-related protein 1 in gastric cancer

瞄准：识别分泌卷发相关的蛋白质的甲基化 1 (SFRP1 ) 在胃的癌症并且到调查有病人的临床的病理学的特征的 SFRP1 和它的关联的异常表示。方法：我们在 3 胃的癌症房间线 SGC-7901 决定了 SFRP1 甲基化和 SFRP1 mRNA 表示， BGC-823， HGC-27，从 52 个主要胃的癌症标本和匹配的肿瘤由甲基化的邻近的织物标本特定(MSP ) PCR 和 RT-PCR 分别地。菲希尔的准确测试被用来分析在临床的病理学的数据和 SFRP1 的异常表示之间的统计协会。结果：在 3 根癌症房间线， BGC-823 和 HGC-27 有甲基化 SFRP1 并且失去了 SFRP1 mRNA 表示。有 demethylating 代理人的 BGC-823 和 HGC-27 的术后疗法， 5-aza-2'-deoxycytidine， SFRP1 被重新表示。在 52 个主要胃的癌症标本和匹配的肿瘤邻近的组织标本， SFRP1 的 hypermethylation 在 23 被检测(44%) 并且 8 (15%) 标本分别地(c2 = 10.34， P 【 0.01 ) 。SFRP1 表示的损失在 17 被检测(33%) 并且 6 (12%) 标本分别地(c2 = 6.75， P 【 0.01 ) 。在 SFRP1 hypermethylation 和 SFRP1 表示损失之间有重要关联。SFRP1 表示也与肿瘤舞台和淋巴节点地位，然而并非与耐心的性别，年龄和组织学的类型显著地被相关。结论：在激活的 SFRP1 是主要 hypermethylation 在胃的癌症引起的一个普通、早的事件。SFRP1 表示损失可以在主要胃的癌症与瘤转移被相关。

AIM： To identify the methylation of secreted frizzled-related protein 1 （SFRP1） in gastric cancer and to investigate the aberrant expression of SFRP1 and its correlation with the clinical pathological features of patients. METHODS： We determined SFRP1 methylation and SFRP1 mRNA expression in 3 gastric cancer cell lines SGC-7901, BGC-823, HGC-27, from 52 primary gastric cancer specimens and matched tumor adjacent tissue specimens by methylation-specific （MSP） PCR and RT-PCR respectively. Fisher＇s exact test was used to analyze the statistical association between clinical pathological data and aberrant expression of SFRP1. RESULTS： In 3 cancer cell lines, BGC-823 and HGC-27 had methylated SFRP1 and lost SFRP1 mRNA expression. After treatment of BGC-823 and HGC-27 with the demethylating agent, 5-aza-2′-deoxycytidine, SFRP1 was re-expressed. In 52 primary gastric cancer specimens and matched tumor adjacent tissue specimens, hypermethylation of SFRP1 was detected in 23 （44%） and 8 （15%） specimens respectively （x^2= 10.34, P 〈 0.01）. Loss of SFRP1 expression was detected in 17（33%） and 6 （12%） specimens respectively （x^2= 6.75, P 〈 0.01）. There was a significant correlation between SFRP1 hypermethylation and SFRP1 expression loss. SFRP1 expression was also correlated significantly with tumor stage and lymph node status, but not with patient sex, age and histological type. CONCLUSION： SFRP1 inactivation is a common and early event caused mainly by hypermethylation in gastric cancer. SFRP1 expression loss may be correlated with tumor metastasis in primary gastric cancer.