中文摘要：

目的检测生长抑制因子4（ING4）在胃癌患者组织及外周血中的表达,探讨其与胃癌发生、发展的相关性及在胃癌诊疗中的应用。方法收集30例胃癌患者手术切除的癌组织、对应的癌旁组织和外周血,用RT-PCR、实时定量RT-PCR、巢式RT-PCR检测ING4 mRNA表达;用western blot和免疫组织化学法在蛋白质水平上进行验证,分析ING4在胃癌中的表达水平与临床病理因素的相关性。结果 RT-PCR和定量结果显示76.7%（23/30）的胃癌组织ING4表达低于对应的癌旁组织,差异有统计学意义（P〈0.05）;western blot和免疫组织化学法在蛋白质水平上证实了胃癌组织较癌旁组织中ING4的表达水平下降。胃癌组织ING4的表达与肿瘤分化状态和复发相关,但与临床分期无关。分化水平越低,ING4 mRNA表达越低（P〈0.05）;复发的患者癌组织ING4 mRNA表达显著低于未复发患者（P〈0.05）。胃癌患者外周血ING4 mRNA的表达也显著低于健康人。结论胃癌组织ING4的表达下调,且与胃癌的分化与复发相关,ING4的基因和蛋白质水平检测可能作为胃癌病程进展或复发监测的新指标。

英文摘要：

Objective To detect the expression of ING4 gene in paired gastric cancer（GC） and non-cancerous tissues,as well as the corresponding blood samples,and explore the correlation between the expression of ING4 gene and the development of human GC,assess the possibility clinical application of ING4 detection for GC diagnosis.Methods The primary tumor tissues,matching adjacent non-cancerous tissues and peripheral blood samples from 30 GC patients were collected.The expressions of ING4 were examined by reverse transcription-PCR（RT-PCR）,real-time RT-PCR and nested RT-PCR.ING4 protein levels were detected by western blot and immunohistochemistry（IHC）.The correlation analysis was conducted to assess the relationship between ING4 expression and clinical pathological parameters.Results The quantitative results of real-time RT-PCR showed that the expression rate of ING4 gene in the matching adjacent non-cancerous tissues was 76.7%（23 /30）,significantly higher than that in gastric tumor tissues（P 0.05）,which was verified by the expression of ING4 protein levels detected by immunohistochemistry and western blot.ING4 expression in gastric cancer tissues correlated with the differentiation status and recurrence of tumor,but not with TNM stage.ING4 mRNA expression in peripheral blood of GC patients was significantly lower than that in healthy controls.Conclusions ING4 expression in gastric cancer tissues was down-regulated,and associated with the differentiation status,recurrence and metabolism of GC.It may be a novel marker for assessing prognosis and recurrence of human GC.