三氧化二砷对乳癌细胞系MDA-MB-468雌激素受体表达的影响

目的:探讨三氧化二砷(As2O3)对人雌激素受体α(ERα)阴性的乳癌细胞株MDA-MB-468进行药物诱导后ERα启动子CPG岛的甲基化状态及蛋白的变化。方法:常规培养MDA-MB-468细胞,采用MTT法检测0.5、1.0、2.0、4.0、8.0和16.0mmol/LAs2O3分别处理24、48和72h后细胞的生长抑制率,甲基化特异性PCR检测1.0、2.0、4.0μmol/LAs2O3处理72h后MDA-MB-468细胞ERα启动子CpG岛的甲基化状态,Westernblot检测1.0、2.0、4.0μmol/LAs2O3处理72h后MDA-MB-468细胞ERα蛋白的表达情况。结果:As2O3可抑制MDA-MB-468细胞增殖,其作用呈时间和剂量依赖性(F浓度=375.603,F时间=474.827,P<0.001)。经1.0、2.0、4.0μmol/LAs2O3处理后的MDA-MB-468细胞启动子CpG岛甲基化水平降低,ERα蛋白重新表达。结论:As2O3明显抑制MDA-MB-468增殖,适当浓度As2O3能诱导ERα去甲基化,使ERα阴性的MDA-MB-468细胞恢复表达ERα。

Influence of estrogen receptor-α expression in breast cancer MDA-MB-468 cells after arsenic trioxide treatment

Aim:To study the DNA and protein change of estrogen receptor-α(ERα) after treatment with different concentrations of arsenic trioxide in breast cancer cell MDA-MB-468.Methods:MDA-MB-468 cells were collected.MTT method was used to analyze cell growth activity after arsenic trioxide treatment by 24,48,72 h.Methylation-specific PCR was utilized to detect the methylation status of CpG island of the promoter of ERα gene and western blot to analyse expression of ERα protein.Results:Arsenic trioxide inhibits proliferation of MDA-MB-468 cells,which had the dose-effect and time-effect(Finteraction=375.603,Ftime=474.827,P<0.001).CpG island of MDA-MB-468 cells demethylated after treated by 1.0,2.0,4.0 μmol/L arsenic trioxide.The ERα protein of MDA-MB-468 cells was re-expressed after treated by 1.0,2.0,4.0μmol/L arsenic trioxide.Conclusion:Arsenic trioxide inhibits proliferation of MDA-MB-468 cells.Certain concentration of arsenic trioxide can demethylate the CpG island of the promoter of ERα and restores expression.