对-壬基酚对MCF-7人类乳腺癌细胞雌激素受体表达的影响

目的　观察对 -壬基酚 (p- NP)对 MCF- 7人类乳腺癌细胞株雌激素受体 (ER)及 ERαm RNA表达的影响 ,探讨其雌激素样活性。方法　以 RPMI 16 4 0培养液 (含 10 %小牛血清 )对 MCF- 7细胞进行半开放式贴壁培养 ,试验前以 DMEM(不含酚红 )培养液洗涤细胞 ,以含 3% C/D胎牛血清的 DMEM(不含酚红 )培养液继续培养 3d。试验设溶剂对照、阳性对照和 p- NP 5个浓度组 ,采用免疫组织化学法和定量 RT- PCR法分别对 MCF- 7细胞 ER蛋白和 ERαm RNA表达情况进行分析。结果　 1× 10 - 5m ol/L p- NP作用于 MCF- 7细胞 2 4 h下调 ER蛋白表达 ;1× 10 - 6 mol/L～ 1× 10 - 5m ol/L p- NP作用于 MCF- 7细胞 2 h和 2 4 h下调 ERαm RNA表达。p- NP各浓度组均表现出 ER蛋白和 ERαm RNA表达随 p- NP作用于 MCF- 7细胞时间的延长而进一步下降的趋势。结论　 p- NP可模拟雌激素下调 MCF- 7细胞 ER蛋白和 ERαm RNA表达 ,具有雌激素样活性

Effects of p-nonylphenol on Expression of ER Protein and ERαmRNA of MCF-7 Cells

OBJECTIVE: To investigate the estrogenicity of p-nonylphenol (p-NP) through observation of its effects on expression of estrogen receptor (ER) and ER alpha mRNA of MCF-7 human breast cancer cells. METHODS: MCF-7 cells were maintained in RPMI-1640 medium containing 10% bovine serum. Before addition of p-NP, the cells were washed by phenol red-free DMEM medium and then maintained in phenol red-free DMEM medium containing 3% charcoal/dextran treated fetal bovine serum for 3 days. The effects of five concentrations of p-NP on expression of ER protein and ER alpha mRNA were assayed using semi-quantitative immunohistochemical method and quantitative RT-PCR respectively, vehicle control and positive control were used. RESULTS: Expression of ER protein in MCF-7 cells was down regulated by 1 x 10(-5) mol/L p-NP when cells were treated for 24 h. Expression of ER alpha mRNA in MCF-7 cells was down regulated by 1 x 10(-6) mol/L-1 x 10(-5) mol/L p-NP when cells were treated for 2 h and 24 h. Expression of both ER protein and ER alpha mRNA in MCF-7 cells showed a tendency of decline when the time of exposure to different concentrations of p-NP was elongated. CONCLUSION: p-NP could down regulate the expression of both ER protein and ER alpha mRNA in MCF-7 cells, which mimicked the effects of estradiol and thus revealed the estrogenicity of p-NP.