胃癌7号染色体长臂的杂合性缺失分析

目的:检测胃癌患者7号染色体长臂微卫星位点的杂合性缺失(loss of heterozygosity,LOH),以初步确定7号染色体长臂上与胃癌相关基因连锁最密切的微卫星多态位点及LOH的临床意义.方法:在70例原发性胃癌中应用多重PCR技术扩增覆盖整个7号染色体长臂的9个微卫星位点(平均遗传距离为10cm),聚丙烯酰胺凝胶电泳分离PCR产物,用GeneScan、Genotyper软件进行分析.结果:9个微卫星位点的LOH均可发生于原发性胃癌,总的LOH频率为34.3%(24/70),其中D7S486和D7S798位点的LOH频率较高,分别为24.0%(12/50)和19.2%(5/26);总的LOH频率随临床分期而显著增高(P=0.046),D7S486位点的LOH频率在淋巴结转移者显著高于无淋巴结转移者(P=0.015).结论:在7号染色体长臂D7S486和D7S798位点附近,可能存在与胃癌发展相关的抑癌基因.

Loss of Heterozygosity Analysis on the Long Arm of Chromosome 7 in Gastric Carcinoma

Objective:In order to define the common deleted region linked to primary gas-tric carcinomas in Chinese loss of heterozygosity(LOH)frequency of human chro mosome 7q and its clinical significance was investigated.Methods:A set of9microsatellite markers on7q with an average marker density of10cM were used to examine matched tumor and non-tumor DNAs from70patients with primary gastric carcinoma for LOH by multi-PCR amplification.The PCR prod-ucts were separated by electrophoresis in polyacrylamide gel.Genescan and Genotyper soft wares were used to analysis LOH.Results:LOH at any locus on7q occurred in34.3%(24/70)of the tumors.Among them,LOH at D7S486and D7S798were Higher,24.0%(12/50)and19.2%(5/26),respectively.The frequency of LOH at any locus on7q was obviously higher and higher with the the rising of clinical stage,P<0.05.The fre quency of LOH at D7S486in cases with lymph node metastasis was obviously higher than that in cases with non-lymph node metastasis,P=0.015.Conclusion:The higher incidence of LOH at D7S486and D7S798in primary gastric carcinoma suggests that there might be a potential TSG involved in the progression of gastric carcinoma.