5-Fu对低氧下胃癌SGC7901细胞系中SP细胞比例及HIF-2、ABCG2表达的影响  

Effect of 5-Fu on the ratio of SP cells and expression of HIF-2α and ABCG2 in human gastric cancer cell line SGC7901 under hypoxia

作　　者：张小茜[1] 冯玉光[1] 吴美英[2] 朱芸[2] 白红霞[2] 王西艳[2] 

机构地区：[1]潍坊医学院附属消化内科,山东省潍坊市261031 [2]潍坊医学院,山东省潍坊市261053

出　　处：《世界华人消化杂志》2012年第20期1813-1818,共6页World Chinese Journal of Digestology

摘　　要：目的:探讨低氧下5-Fu化疗抵抗的机制.方法:MTT检测常氧和低氧下的细胞活力,并计算5-Fu的半数抑制浓度(IC50).以IC50的5-Fu分别作用细胞常氧和低氧组细胞24、48和72h后,收集标本,Hoechst33342染色法检测侧群(side population,SP)细胞的比例,免疫细胞化学法检测低氧诱导因子(hypoxia-inducible factor-2α,HIF-2α),荧光免疫细胞化学法检测ABCG2(ATP-binding cassettesuperfamily Gmember 2)的表达.结果:常氧和低氧下,5-Fu均呈时间、剂量依赖性地抑制SGC7901细胞增殖,其IC50分别为100、200mg/L.常氧下SP细胞的比例为1.87%,低氧诱导后其比例逐渐增加.常氧下5-Fu-IC50作用于细胞不用时间后,SP细胞的比例无明显变化,低氧下其比例却逐渐增加.常氧下,HIF-2和ABCG2蛋白呈低水平表达,且5-Fu-IC50作用于不同时间后也无明显变化,低氧下5-Fu-IC50作用于不同时间后二者的表达逐渐增加.结论:低氧下5-Fu对胃癌SGC7901细胞存在化疗抵抗可能与低氧通过诱导HIF-2α-ABCG2通路的表达、促进肿瘤细胞的干细胞化有关,这可能是肿瘤化疗抵抗和复发的根源.AIM： To investigate the mechanism of resistance to 5-fluorouracil （5-Fu） chemotherapy in gastric cancer cells under hypoxia. METHODS： The proliferative activity of SGC7901 cells was determined by MTT assay, and the half maximal inhibitory concentration （ICs0） of 5-Fu under normoxia and hypoxia was calculated. After 5-Fu at a concentration of ICs0 was incubated with cells for 24, 48 or 72 h under hypoxia, the percentage of SP cells was detected by Hoechst 33342 staining, the expression of HIF-2c~ protein was detected by immunocyto- chemistry, and the expression of ABCG2 was detected by fluorescence immunocytochemistry. RESULTS： 5-Fu inhibited the proliferation of SGC7901 cells in a dose- and time-dependent manner under normoxia and hypoxia. The ICs0 of 5-Fu under normoxia and hypoxia was 100 mg/L and 200 mg/L, respectively. The ratio of SP cells in SGC7901 cells was 1.87% under nomoxia, and significantly increased after induction by hypoxia for 24, 48, and 72 h. Treatment with 5-Fu had no significant impact on the propor- tion of SP cells under normoxia, but gradually increased SP cell proportion under hypoxia. The expression levels of HIF-2c~ and ABCG2 proteins in SGC7901 cells were lower under normoxia. Treatment with 5-Fu had no significant impact on the expression of HIF-2~ and ABCG2 pro- teins under normoxia, but gradually increased their expression under hypoxia. CONCLUSION： The mechanism underlying the resistance of SGC7901 cells to 5-Fu under hypoxia may be related to inducing HIF-2~ and ABCG2 expression and promoting stemness.

关 键 词：5-FU 低氧 肿瘤干细胞 侧群细胞 ABCG2 低氧诱导因子-2α 

分 类 号：R735.2[医药卫生—肿瘤]