低氧对人胃癌SGC7901细胞株SP细胞比例的影响与HIF-2α、OCT-4表达变化的关系  

Effect of hypoxia on ratio of SP cells and its relationship with expression of HIF-2α and OCT-4 in gastric cancer SGC7901 cell line

作　　者：吴美英[1] 冯玉光[2] 朱芸[1] 

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

出　　处：《现代医药卫生》2011年第7期979-981,共3页Journal of Modern Medicine & Health

摘　　要：目的:通过观察低氧对人胃癌SGC7901细胞株侧群(side population,SP)细胞比例的影响及其与HIF-2α和OCT-4表达变化的关系,初步研究低氧对肿瘤干细胞的影响及机制。方法:Hoechst33342染色检测人胃癌SGC7901细胞系SP细胞比例,免疫荧光化学法检测OCT-4在SP和非SP细胞中的表达,免疫细胞化学法检测HIF-2α和OCT-4蛋白的表达。结果:常氧下人胃癌SGC7901细胞系中SP细胞的比例为2.36%,低氧诱导24、48、72h后其比例逐渐增加,分别为3.01%、3.23%、3.45%(P<0.05);常氧下OCT-4在SP和非SP细胞中的表达差异无统计学意义(P>0.05),低氧诱导24、48、72h后,OCT-4在SP细胞和非SP细胞中的表达逐渐增强(P<0.05),在SP细胞中的表达要高于非SP细胞。常氧下HIF-2α和OCT-4蛋白呈低水平表达,低氧诱导24、48、72h后,二者的表达逐渐增加(P<0.05),且HIF-2α和OCT-4蛋白呈高度正相关(P<0.05)。结论:低氧可使人胃癌SGC7901细胞系中的SP细胞增多,其机制可能与低氧诱导HIF-2α-OCT4通路的表达,促进肿瘤细胞的干细胞化及维持干细胞的未分化状态有关。Objective：To observe the effect of hypoxia on the ratio of side population（SP） cells of human gastric cancer SGC7901 cell line and its relationship with the expression of hypoxia inducible factor-2alpha（HIF-2α） and OCT-4 and to initially investigate the effect of hypoxia on cancer stem cells and its mechanism.Methods：The percentage of SP cells in the human gastric cancer SGC7901 cell line was detected by Hoechst33342 staining.Immunofluorescence cytochemistry was adopted to detect the expression of OCT-4 in SP and non-SP cells.Immunocytochemical staining was used to detect the expression of HIF-2α and OCT-4 protein.Results：The ratio of SP cells under normoxia was 2.36% in the human gastric cancer SGC7901 cell line,while after induced by hypoxia for 24,48,72h respectively,there was a statistically significant increase when compared with the normoxia,which had 3.01%,3.23% and 3.45% respectively（P0.05）.The expression of OCT-4 between SP and non-SP cells under normoxia was no significant difference,while after induced by hypoxia for 24,48,72h respectively,its expression significantly increased in a time-dependent manner both in the SP and non-SP cells when compared with the normoxia（P0.05）,and its expression in SP cells was more higher than in non-SP cells.The expression of HIF-2α and OCT-4 protein incubated under hypoxia for 24,48,72h respectively was evidently higher than that in the normoxia group（P0.05）.A significant positive correlation was noted between the expression of HIF-2α and OCT-4 in SGC7901 cells.Conclusion：Hypoxia can increase the ratio of SP cells in human gastric cancer cell line SGC7901.The mechanism may be involved in HIF-2α-OCT-4 pathway activated by hypoxia,and it suggests that hypoxia could increase cancer cell stemness by promoting cancer cells dedifferentiation and maintaining cancer stem cells undiferentiated state.

关 键 词：低氧 胃癌细胞 SP细胞 低氧诱导因子-2α OCT-4 

分 类 号：R73[医药卫生—肿瘤]