幽门螺杆菌感染与APC基因突变的关系

Helicobacter pylori infection irrelevant to APC mutation in gastric cancer

目的 探讨幽门螺杆菌 (Hp)感染与APC基因突变的关系。方法 采用改良的Giemsa染色和PCR方法检测Hp;采用DGGE电泳和DNA测序技术检测APC突变。结果 6 8例胃癌中检出APC基因突变 15例 ,突变率为 2 2 .1%。APC突变率在肠型胃癌显著高于弥漫型胃癌 (P <0 .0 5 )。将MSI分为高频率MSI(MSI H ,≥ 2个位点 ) 8例、低频率MSI(MSI L ,仅为 1个位点 ) 9例和MSI阴性 (MSS) 5 1例 3组 ,结果APC突变均发生于MSI L和MSS组 ,而MSI H组未发现有APC突变者。APC基因突变在Hp+组和Hp -组及CagA +组和CagA -组检出率均无显著差异 (P >0 .0 5 )。结论 APC突变参与了LOH途径 ;

Objective To evaluate the relationship between APC and hMLH1 mutation and promoter methylation and helicobacter pylori(Hp) infection in gastric carcinomas. Methods hMLH1 and APC mutation was measured by two dimentional DNA electrophoresis, denaturing gradient gel electrophoresis and DNA sequencing;methylation of hMLH1 promoter was measured with methylation specific PCR;Hp was detected using PCR and modified Giemsa staining. Results Sixty eight cases of sporadic gastric carcinoma were studied for APC mutation. APC mutaions were detected in 15(22.1%)gastric cancers. APC mutations were associated with intestinal type of gastric cancer ( P <0.05). By using five microsatellite markers, MSI in at least one locus was detected in 17 of 68 (25%) of the tumors analyzed. hMLH1 mutations were all detected in MSI H (≥2 loci, n =8), but no mutation was found in MSI Low (only one locus, n =9) or MSS(tumor lacking MSI or stable, n =51). APC mutations were all detected in MSI Low or MSS, but no mutation was found in MSI H. Conclosion APC mutation is involed in LOH pathway in gastric cancer,and APC mutation is not related to Hp infection in gastric cancer.