二十二碳六烯酸促进无葡萄糖条件下乳腺癌细胞MDA-MB-231死亡

Docosahexaenoic Acid Promoted Death of Breast Cancer MDA-MB-231 Cells under Glucose Deprivation

为了探究二十二碳六烯酸(docosahexaenoic acid,DHA)抗乳腺癌的机制,采用流式细胞术分析细胞死亡率,H2DCFDA探针流式细胞术测定细胞内活性氧(reactive oxygen species,ROS)水平,Western blotting方法检测细胞内剪切型Caspase-3的变化。结果发现在无葡萄糖条件下,DHA以浓度依赖性方式促进乳腺癌细胞MDA-MB-231死亡。在这个过程中,DHA促使细胞内ROS水平明显升高,然而,当DHA和抗氧化剂N-乙酰-半胱氨酸(N-acetyl-L-cystein,NAC)共处理细胞时,细胞死亡率和细胞内ROS水平均明显降低。Western blotting检测结果表明DHA可以引起Caspase-3的切割,同时,这种变化可以被NAC抑制。结果表明在无葡萄糖条件下,DHA可以通过增加细胞内ROS的水平,激活Caspase凋亡通路,进而促进乳腺癌细胞MDA-MB-231死亡。

To study the effects of docosahexaenoic acid （DHA） on breast cancer cells and the underlying mechanisms, celt death was detected by flow cytometry （FCM） with PI fluorescence staining. Intracellular reactive oxygen species （ROS） was measured by FCM using H2DCFDA. The activity of Caspase-3 protein was examined by Western blotting. The results showed that.. DHA could enhance the death of MDA-MB-231 cells after 24 h treatment in a concentration-dependent manner under the condition of glucose starvation. The FCM with the probe of DCF indicated that DHA markedly promoted accumulation of intracellular ROS. However, after treatment with N-acetyI-L-cystein （NAC）, the death rate of cells and the ROS level decreased. Western blotting analysis confirmed that co-treatment with NAC could partially attenuate the cleavage of Caspase-3 induced by DHA. The data demonstrated that DHA could enhance the death of glucose-starved MDA-MB-231 cells, which was associated with intracellular accumulation of ROS and activation of Caspase pathway.