氧浓度与CagA^+幽门螺杆菌对人胃癌SGC7901细胞系HIF-2α和Oct-4表达影响的研究  

Effects of CagA^+ H.pylori on the expressions of HIF-2α and Oct-4 of human gastric cancer cell line SGC7901 under normoxia and hypoxia condition respectively

作　　者：高桂鹏[1] 冯玉光[2] 张金花[1] 丁娜[2] 李蕾[2] 仲华[2] 

机构地区：[1]潍坊医学院研究生部,山东潍坊261042 [2]潍坊医学院附属医院消化内科,山东潍坊261031

出　　处：《中华肿瘤防治杂志》2013年第9期666-670,共5页Chinese Journal of Cancer Prevention and Treatment

摘　　要：目的:通过观察常氧与低氧下CagA+幽门螺杆菌(Hp)对人胃癌SGC7901细胞系HIF-2α和Oct-4表达的影响,初步探讨Hp在胃癌发生发展中的干细胞机制,及其与肿瘤微环境低氧的协同作用。方法:内镜下采集胃黏膜标本后行Hp培养并鉴定,PCR方法鉴定CagA基因。CagA+Hp与胃癌SGC7901细胞于常氧和低氧环境下共培养48h(分常氧对照组、低氧对照组、常氧CagA+Hp组、低氧CagA+Hp组)。免疫细胞化学法检测HIF-2α和Oct-4蛋白的表达,RT-PCR法检测Oct-4mRNA的表达。结果:免疫细胞化学结果显示,常氧下胃癌SGC7901细胞HIF-2α和Oct-4蛋白呈低水平表达,表达量分别为0.263 9±0.008 0和0.317 9±0.001 3。低氧和CagA+Hp均能显著诱导HIF-2α和Oct-4蛋白表达,与常氧对照组的相比,HIF-2α表达量为0.431 8±0.001 2和0.422 5±0.017 0,t值分别为46.410 3和18.875 6,P<0.01;Oct-4为0.546 8±0.008 2和0.478 9±0.001 8,t值分别为61.649 1和162.139 0,P<0.01。与低氧对照组和常氧CagA+Hp组相比,低氧CagA+Hp组蛋白表达量进一步升高,HIF-2α为0.507 7±0.007 0,t值分别为23.896 8和10.362 5,P<0.01;Oct-4为0.698 7±0.005 1,t值分别为35.173 7和90.876 1,P<0.01。相关分析显示,HIF-2α与Oct-4表达呈正相关,r=0.964 0,P<0.05。RT-PCR检测各组Oct-4mRNA表达结果显示与免疫细胞化学结果一致。结论:常氧下CagA+Hp可刺激胃癌细胞HIF-2α和Oct-4表达,低氧环境下其表达进一步增加,表明CagA+Hp和低氧对HIF-2α和Oct-4的表达有协同作用。提示CagA+Hp和低氧可能是诱导胃癌细胞干细胞化的重要原因。OBJECTIVE： To observe the effects of CagA＋ H. pylori on the expressions of HIF-2a and Oct-4 of human gastric cancer cell line SGC7901 under normoxia and hypoxia condition respectively,initially investigating the stem cell related mechanisms of H. pylori in the initiation and development of gastric cancer,and the synergistic effects between H. pylori and the tumor microenvironment hypoxia on the gastric cancer cell. METHODS： Gastric mucosa biopsy specimens by endoscope was cultured under microaerophilic conditions and H. pylori isolates were identified. CagA＋ H. pylori strains were confirmed by PCR. Gastric cancer cell line SGC7901 was co-cultured with one CagA＋ H. pylori strain for 48 h under normoxia and hypoxia condition respectively （divided into normoxia control group, hypoxia control group, nor- moxia plus CagA＋ H. pylori, hypoxia plus CagA＋ H. pylori group）. Immunocytochemistry was used to detect the expres- sion of HIF-2a and Oct-4 protein,RT-PCR was used to detect the expression of Oct-4 mRNA. RESULTS： Immunocyto- chemistry results showed that HIF-2a and Oct-4 protein expressed at low levels under normoxia, the expression levels were 0. 263 9±0. 008 0 and 0. 317 9~0. 001 3 respectively. Compared to the normoxia control group,hypoxia and CagA＋ H. pylori both could significantly induce the expression of HIF-2a and Oct-4 protein, the expression levels of HIF-2 were 0.431 8＋0. 001 2 and 0. 422 5±0. 017 0,t values were 46. 410 3 and 18. 875 6,and all P〈0. 01;Oct-4 were 0. 546 8±0. 008 2 and 0. 478 9±0. 001 8,t values were 61. 649 1 and 162. 139 0,and all P〈0.01. Compared to the hypoxia control group and normoxia plus CagA＋ H. pylori group, the expression of HIF-2αand and Oct-4 protein in hypoxia plus CagA＋ H. pylori group were further elevated, HIF-2α was 0. 507 7±0. 007 0 ,t values were 23. 896 8 and 10. 362 5 ,and all P〈0.01 ,and Oct-4 was 0. 698 7±0. 005 1 ,t values were 35. 173 7 and 90. 876 1 ,and P〈0.01. Correlation analysis showed a positive correlation betwee

关 键 词：胃肿瘤 螺杆菌 幽门 细胞毒素类 细胞低氧 基因表达 氧 

分 类 号：R735.2[医药卫生—肿瘤]