三氧化二砷在低氧下对人肝癌细胞株HepG2增殖、凋亡及HIF-1α表达的影响  

Effects of arsenic trioxide on cell proliferation,apoptosis and HIF-1α expression in human liver cancer HepG2 cells cultured under hypoxic conditions

作　　者：夏德涛[1] 张栋[2] 肖伟玲[1] 

机构地区：[1]潍坊医学院临床医学系,山东省潍坊市261053 [2]潍坊医学院附属五莲县人民医院,山东省日照市262300

出　　处：《世界华人消化杂志》2010年第24期2515-2520,共6页World Chinese Journal of Digestology

基　　金：潍坊医学院青年教师科研启动基金资助项目;No.KQ07007~~

摘　　要：目的:探讨低氧条件下三氧化二砷(As2O3)对人肝癌细胞株HepG2增殖、凋亡及HIF-1α表达的影响.方法:用氯化钴(CoCl2)创造低氧条件,取1.0、2.0、4.0、8.0μmol/L的As2O3分别在常氧和低氧条件下作用于HepG2细胞12、24和48h后,MTT法检测细胞活力,Hoechst染色法检测细胞凋亡.设常氧对照组、低氧对照组、低氧下不同浓度As2O3(4.0、8.0μmol/L)组,用免疫细胞化学法观察不同浓度As2O3作用于HepG2细胞48h后HIF-1α蛋白表达的变化.结果:MTT法和Hoechst染色法分别显示,在常氧和低氧两种条件下,As2O3均呈时间剂量依赖性地抑制和诱导HepG2细胞增殖和凋亡(均P<0.01),8.0μmol/LAs2O3作用HepG2细胞48h后其抑制率和凋亡率分别为38.40%,37.83%和45.25%,49.28%.在常氧和低氧两种条件下,HepG2细胞生长抑制率及凋亡率的差异均无统计学意义.免疫细胞化学法显示,常氧条件下HIF-1α蛋白呈弱阳性表达,低氧诱导48h后HIF-1α蛋白表达显著升高(t=114.37,P<0.05),低氧条件下HIF-1α蛋白表达随As2O3浓度的增加而逐渐降低(F=347.042,P<0.01).结论:低氧条件下,As2O3能抑制HepG2细胞增殖并诱导其凋亡,其机制可能与As2O3下调HIF-1α的表达有关.AIM：To investigate the effects of arsenic trioxide（As2O3） on cell proliferation,apoptosis and hypoxia-inducible factor-1α（HIF-1α）expression in human liver cancer HepG2 cells cultured under hypoxic conditions.METHODS：Hypoxia was induced with cobalt chloride（CoCl2）.After HepG2 cells were incubated with different concentrations of As2O3（1.0,2.0,4.0 and 8.0 μmol/L） for 12,24 and 48 h under hypoxic conditions,cell proliferation was determined by MTT assay,and cell apoptosis was evaluated by Hoechst staining.HepG2 cells were then divided into three groups：normal control group,hypoxia group,and As2O3 treatment group.After HepG2 cells were incubated with As2O3 at concentrations of 4.0 and 8.0 μmol/L for 48 h under hypoxia,the expression of HIF-1α protein was detected by immunocytochemistry.RESULTS：As2O3 inhibited proliferation but induced apoptosis of HepG2 cells in a doseand time-dependent manner under both normoxic and hypoxic conditions（both P 0.01）.No significant differences were noted in the reduced proliferation rates of cell proliferation（38.40% vs 37.83%,P 0.05）and apoptosis rates（45.25% vs 49.28%,P 0.05）between HepG2 cells treated with 8.0 μmol/L As2O3 for 48 h under normoxic and hypoxic conditions.Immunocytochemistry analysis revealed that HIF-1α was weakly expressed in HepG2 cells under normoxia.After hypoxic induction for 48 h,HIF-1α expression was significantly up-regulated（t = 114.37,P 0.05）.The expression of HIF-1α protein gradually decreased with the increase in the concentration of As2O3 under hypoxia（F = 347.042,P 0.01）.CONCLUSION：As2O3 can inhibit proliferation but induce apoptosis of HepG2 cells under hypoxia possibly by down-regulating HIF-1α protein expression.

关 键 词：三氧化二砷 低氧 肝癌细胞 低氧诱导因子-1Α 

分 类 号：R735.7[医药卫生—肿瘤]