飞燕草素通过AKT/mTOR通路诱导HER-2+乳腺癌细胞自噬

目的：研究飞燕草素对HER-2+乳腺癌细胞MDA-MB-453自噬的诱导作用及其分子机制。方法：以不同浓 度飞燕草素处理MDA-MB-453细胞，CCK-8检测细胞增殖情况；TdT介导的脱氧尿嘧啶缺口末端标记(TdT-mediated dUTP nick end labeling，TUNEL)和Western印迹检测细胞凋亡和与凋亡相关蛋白的表达；荧光斑点、免疫荧光和Western 印迹检测自噬的诱导情况和诱导机制。 结果：飞燕草素抑制MDA-MB-453细胞增殖，增加TUNEL阳性细胞数，下调 caspase-3 和caspase-9蛋白活性，上调裂解的caspase-3和裂解的caspase-9蛋白活性。飞燕草素增加GFP-LC3荧光斑点数、 LC3免疫荧光斑点数、LC3-II和ATG5蛋白表达。飞燕草素下调mTOR通路蛋白AKT，mTOR，eIF4E和p70s6k蛋白活 性。结论：飞燕草素诱导HER-2+乳腺癌细胞MDA-MB-453凋亡的同时通过抑制AKT/mTOR通路诱导细胞自噬。

Delphinidin induces autophagy in HER-2+ breast cancer#br# cells via inhibition of AKT/mTOR pathway

Objective: To explore the effect of delphinidin on breast cancer and the underlying mechanisms. Methods: Human epidermal growth factor receptor-2 (HER-2) positive breast cancer cells MDAMB- 453 were treated by delphinidin. Proliferation of MDA-MB-453 cells was detected by CCK-8 after 48 h. TdT-mediated dUTP nick end labeling (TUNEL) assay and Western blot were used to explore apoptotic status for MDA-MB-453 cells. Fluorescence dot assay, immunofluorescence, and Western blot were used to identify autophagy in breast cancer cells. Results: Delphinidin suppressed proliferation of MDA-MB-453 cells. Delphinidin increased the number of TUNEL positive cells. Delphinidin downregulated the expression of caspase-3 and caspase-9, while upregulated the expression of cleaved caspase-3 and cleaved caspase-9 ina dose-dependent manner. Delphinidin enhanced the number of GFP-LC3 punctate dots, LC3 immunofluorescence dots and the expression of LC3-II and ATG5. Delphinidin inhibited the expression of proteins in mTOR signaling pathway, including AKT, mTOR, eIF4E and p70s6k. Conclusion: Delphinidin induced apoptosis and autophagy by inhibition of AKT/mTOR pathway in HER positive breast cancer cells.