环境雌激素对乳腺癌细胞株MCF-7凋亡作用的影响

Effects of Environmental Estrogens on Apoptosis in MCF-7 Cells

[目的 ]通过观察对 壬基酚 (nonylphenol ,NP)、双酚A(bisphenolA ,BisA)和邻苯二甲酸二丁酯 (dibutylphthalate ,DBP)对乳腺癌细胞株MCF 7凋亡的影响 ,探讨环境雌激素促进MCF 7细胞增殖的生物学机制。 [方法 ]将在DMEM培养液 (含 10 %小牛血清 )中的MCF 7细胞采用开放式单层贴壁培养 ,加受试物前 5d将培养细胞用PBS洗涤后改为在无酚红DMEM(含 5 %经活性碳 葡聚糖苷处理的胎牛血清 ,CDT FBS)中培养连续 5d ,其目的是耗尽细胞内储存的雌激素。实验设溶剂对照组、雌激素对照组、抗雌激素 (它莫西芬 )对照组及三个实验组 ,采用流式细胞术、DNA片段凝胶电泳和细胞苏木素染色 (HE) ,观察环境雌激素对雌激素耗尽所诱导的细胞凋亡作用的影响。 [结果 ] 3 2× 10 -6mol/LNP和 3 2×10 -5mol/LBisA对MCF 7细胞处理 72h ,与对照组相比 ,流式细胞仪分析结果表明 ,二倍体细胞 (G1期细胞 )明显增加 ,亚二倍体细胞峰 (即细胞凋亡率 )消失 ,DNA凋亡片段凝胶电泳不显示典型的凋亡DNA片段梯带 ,细胞苏木素染色结果也显示凋亡细胞明显减少。 [结论 ]与溶剂对照组相比 ,NP和BisA均能够抑制MCF 7细胞的凋亡作用 ,而 3 2× 10 -4mol/LDBP对细胞凋亡的影响作用不明显。这一结果提示 ,该类物质有可能是通过抑制细胞凋亡而?

The current research has focused on effects of n nonylphenol(NP),bisphenol A (BisA) and dibutylphthalate(DBP) on apoptosis induced in human breast cancer MCF 7 cells. Human estradiol dependent MCF 7 breast cancer cells were grown in DMEM medium complemented with 10% bovine serum. For 5 days before the addition of the test chemicals,the cells were washed by phosphate buffered saline,and the medium was substituted with a phenol red free DMEM medium containing 5% dextran charcoal stripped FBS. The respective test chemical was added into fresh medium and the control cells treated only with the vehicle(ethanol). Apoptotic features in MCF 7 cells were analyzed by light microscope based on chromatin condensation,disappearance of nucleoli, formation of membrane blebs,apoptotic bodies,and cell shrinkage. DNA integrity of MCF 7 cells was examined by agarose gel electrophoresis. The rate of cell hypodiploid was indicated by flow cytometry analysis. The typical characters of apoptosis in MCF 7 cells were observed after estrogen deletion and then gradually disappeared following exposure of MCF 7 cells to 3 2×10 -6 mol/L NP and 3 2×10 -5 mol/L BisA,respectively.Inhibition of apoptosis at a concentration of 3 2×10 -4 mol/L DBP was not found. [Conclusion] N 4 nonyphenol and bisphenol A could inhibit apoptosis induced by estrogen deletion in breast cancer MCF 7 cells.This result suggests that these environmental estrogens might be involved in signal transduction associated with apoptosis.