内源性端粒酶抑制基因遗传不稳定性与胃癌进展的关系

目的 研究8号染色体上D8S277位点的杂合性缺失(LOH)和微卫星不稳定性(MSI)对内源性端粒酶抑制基因(PINX1)蛋白表达的影响,阐明PINX1基因遗传不稳定性与胃癌进展的关系. 方法采用石蜡包埋组织抽提DNA,聚合酶链-单链构象多态性(PCR-SSCP)分析,常规银染检测D8S277位点的LOH和MSI,采用Envision免疫组织化学染色和Leica-Qwin计算机图像分析等方法. 结果 D8S277位点的LOH发生率在淋巴结转移组(21.15%)明显高于无淋巴结转移组(0,P<0.05);在胃癌TNM Ⅲ Ⅳ期(24.39%)显著高于Ⅰ Ⅱ期(3.33%,P<0.05).PINX1蛋白阳性率在无淋巴结转移组(78.95%)明显高于有淋巴结转移组(48.08%,P<0.05);TNM分期Ⅰ Ⅱ期(73.33%)明显高于Ⅲ Ⅳ期(43.90%,P<0.05);蛋白表达阴性组LOH阳性率为32.28%,明显高于蛋白阳性组的2.50%(P<0.01). 结论 PINX1基因的遗传不稳定性可能导致该抑癌基因突变,是肿瘤发生发展的一个因素,LOH和MSI通过不同的途径调控胃癌的发生和发展.

THE RELATIONSHIP BETWEEN THE INSTABILITY OF PINX1 GENE AND GASTRIC CARCINOMA

Objective To examine loss of heterozygosity(LOH) and microsatellite instability(MSI) of locus D8S277 on chromosome 8 and their influence on the expression of PINX1 in the gastric carcinoma,which may provide an experimental basis for the mechanism of PINX1 gene and tumor development.Methods DNA was extracted from formalin-fixed paraffin-embedded tissues.Polymerase chain reaction-single strand conformation polymorphism(PCR-SSCP) and ordinary silver staining were used to study LOH and MSI of locus D8S277.Envis...