雌激素受体在人乳腺癌MCF-7细胞阿霉素敏感株和耐药株中的变化及意义

ER status in adriamycin-sensitive and adriamycin-resistant MCF-7 human breast cancer cell lines

目的研究MCF 7人乳腺癌细胞阿霉素敏感株 (MCF 7)和耐药株 (MCF 7/ADR)细胞中雌激素受体 (estrogenreceptor,ER)表达的变化与其对细胞生物学特性的影响。方法采用Westernblot法检测MCF 7细胞和MCF 7/ADR细胞中雌激素受体表达 ,RT PCR检测 2株细胞ERmRNA的表达水平 ,MTT法检测细胞增殖及细胞对雌激素 (estrogen ,E2 )和屈洛昔芬 (droloxifene ,Dro)的敏感性 ,流式细胞仪检测细胞周期变化。结果经Westernblot检测 ,MCF 7细胞ER为阳性 ,而MCF 7/ADR细胞ER为阴性 ,采用RT PCR可检测到MCF 7细胞中ER的mRNA ,而在MCF 7/ADR细胞则检测不到。经MTT分析 ,与MCF 7相比 ,MCF 7/ADR细胞生长速度减慢 ,细胞多分布于G0 /G1期。E2 在 1× 10 -12mol/L的浓度时开始促进MCF 7细胞的生长 ,到达 1× 10 -9mol/L时促生长作用进入平台期 ;而任何浓度的E2 对MCF 7/ADR细胞均无促生长作用。Dro的浓度达到 10 μmol/L的时候 ,开始出现对MCF 7细胞生长的浓度依赖性抑制 ,当Dro浓度达到 2 0 μmol/L时对MCF 7/ADR细胞的生长出现明显抑制 ,且高于对MCF 7细胞的抑制。结论MCF 7/ADR细胞雌激素受体表达缺失 ,缺失发生在mRNA水平以上 ,细胞生长速度减慢 ,同时细胞失去对雌激素的依赖性。

Objective To study the ER status in Adriamycin-sensitive and Adriamycin-resistant MCF-7 human breast cancer cell lines. MethodsThe status of ER of MCF-7/ADR and parental MCF-7 cells was detected by Western blot. The expression of ER mRNA was detected by RT-PCR .The growth and the sensitivity to Estrogen(E 2) and droloxifene(Dro) of cells were investigated by MTT assay, and the distribution of cell cycle was detected by flow cytometric assay. Results ER and ER mRNA were positive in MCF-7 cells, and negative in MCF-7/ADR cells. In comparison with MCF-7 cells, MCF-7/ADR cells showed lower growth rate, and the cell cycle was arrested at G 0/G 1 phase. E 2 at concentrations between 1×10 -12mol/L to 1×10 -7mol/L significantly stimulated the growth of MCF-7, but did not stimulate the growth of MCF-7/ADR.Dro at concentrations between 10*!μmol/L to 20*!μmol/L significantly inhabited the growth of MCF-7, and the inhibition was dose-dependent. Dro at concentrations below 20*!μmol/L did not inhibit the growth of MCF-7/ADR, dro inhabited the growth of MCF-7/ADR only at the concentration of 20*!μmol/L, and the inhibition was more effective than MCF-7. Conclusions ER was lost in MCF-7/ADR cells,probably at mRNA level. Compared with MCF-7, the growth rate of MCF-7/ADR decreased,MCF-7/ADR cells lost the dependence on estrogen and the sensitivity to endocrine therapy.