中文摘要：

目的 探讨Line-1（long interspersed nucleotide element-1）甲基化水平与胃癌临床病理特征的关系.方法 收取30例胃癌标本和癌旁正常组织,采用焦磷酸测序技术（Pyrosequencing）对胃癌组织和癌旁正常组织Line-1甲基化水平进行检测.结果 30例胃癌患者胃癌组织中Line-1甲基化平均水平65.8%,而正常组织为75.1%,差异有统计学意义（P＜0.05）;30例胃癌组织中,Line-1甲基化水平在不同的发病性别、发病年龄、发生位置和分化程度中差异无统计学意义（P＞0.05）;Line-1甲基化程度与浸润深度（T1/T2：68.9%、T3/T4：61.3%）、淋巴结转移（NO：70.0%、N1：69.9%、N2：61.7%、N3：57.6%）和远处转移（MO：67.9%、M1：59.1%）明显相关（P＜0.05）,并且随着胃癌的进展而降低.结论 Line-1低甲基化与胃癌浸润和转移有关,可能参与胃癌的进展.

英文摘要：

Objective To elucidate the correlation of methylation of long interspersed nucleotide element-1 （Line-1） with clinicalopathological features of gastric cancer.Methods Gastric cancer tissues and paracancerous tissues were collected from 30 patients and methylation status of Line-1 was detected in caner and corresponding normal tissues by using Pyrosequencing.Results The methylation level of Line-1in normal gastric and gastric cancer tissues was 75.1% and 65.8% respectively （P〈0.05）.Among 30cancer tissues,methylation status of Line-1 was closely related to tumor infiltration （T1/T2：68.9%,T3/T4：61.3% ）,lymph nodes metastasis （ NO：70.0%,N1：69.9%,N2：61.7%,N3：57.6% ） and distant metastasis （ MO：67.9%,M1：59.1% ） （ P 〈0.05） and declined with tumor progression,but wasn＇t associated with age,gender,location and differentiation （ P〉 0.05 ）.Conclusion Hypomethylation of Line-1 was remarkably related to infiltration and metastasis of gastric cancer and may contribute to the tumor progression.