中文摘要：

目的研究肿瘤抑制基因RAS相关区域家族1A（RASSFIA）和死亡相关蛋白激酶（DAPK）基因启动子在视网膜母细胞瘤（RB）组织和外周血的甲基化状态。方法对RB石蜡组织切片进行实验研究，对RB患者和正常人进行病例对照研究，应用甲基化特异性聚合酶链式反应技术检测28例RB组织、9例RB患者外周血中RASSF1A和DAPK基因启动子的甲基化状态，分别收集年龄、性别相匹配的5例角膜捐赠者死亡后获取的正常视网膜、5例健康志愿者的血清作为对照，采用Fisher确切概率法比较两组间甲基化率的差异。结果RB组织中RASSFIA基因启动子的甲基化率为60．7％（17／28），高于正常人视网膜组织0％（0／5）或瘤旁组织17．9％（5／28），差异有统计学意义（P〈0．01），且单侧RB组织的甲基化率（72．7％）高于双侧（16．7％）。另外在2例（2／9）RB患者外周血中检测到RASSFIA基因启动子的高甲基化。而DAPK基因启动子在RB组织及患者外周血中均未发生甲基化。结论RASSFIA基因启动子高甲基化是RB中一种常见频发的表观遗传修饰。

英文摘要：

Objective To investigate the methylation status of RASSFIA or DAPK promoter in retinoblastoma tissue or peripheral blood from retinoblastoma patients. Methods It was an experimental study on the parafin-embeded retinoblastoma tissue sections, and a case-control study on retinoblastoma cases and normal control people. Methylation status of RASSFIA and DAPK promoter in 28 RB tissues and 9 available peripheral blood samples of RB patients were detected by methylation specific polymerase chain reaction （MSP）. Normal retinal tissues from five donor cadaver eyes and normal-peripheral blood samples from five healthy volunteers matched on age and sex were used as controls. The differences of methylation rate among different groups were analyzed statistically by Fisher＇s exact probability test. Results The percentage of RASSFIA hypermethylation in RB tissues （60. 7% ） was statisticantly higher than in normal retinal tissue 0% （ 0/5 ） and adjacent non-neoplastic retinal tissue 17. 9% （ 5/28 ） （ P 〈 0. 01 ）, the hypermethylation percentage in unilateral RB group was higher than bilateral RB group either. Meanwhile, RASSFIA hypermethylation in peripheral blood was detected in 2 of 9 RB cases, showing no statistics difference compared with that of normal person. However, no DAPK promoter hypermethylation was found in all RB tissues and peripheral blood from retinoblastoma patients. Conclusion RASSFIA promoter hypermethylation was frequently present in retinoblastoma, which may play an important role during the pathogenesis of retinoblastoma.