槲皮素对人前列腺癌PC-3细胞自噬及磷脂酰肌醇3激酶/蛋白激酶B/哺乳动物雷帕霉素靶蛋白信号通路的影响

Effects of Quercetin on Autophagy and Phosphatidylinositol 3-kinase/Protein Kinase B/Mammalian Target of Rapamycin Signaling Pathway in Human Prostate Cancer PC-3 Cells

目的观察槲皮素对人前列腺癌PC-3细胞活力、凋亡、自噬及磷脂酰肌醇3激酶(PI3K)/蛋白激酶B(Akt)/哺乳动物雷帕霉素靶蛋白(mTOR)信号通路的影响。方法体外培养PC-3细胞,采用CCK-8法检测PC-3细胞活力,TUNEL染色检测PC-3细胞凋亡,吖啶橙染色观察PC-3细胞自噬小泡,GFP-LC3质粒转染分析观察PC-3细胞自噬小体,Western blot分析检测自噬相关蛋白微管相关蛋白1轻链3融合蛋白(LC3)、Beclin-1和PI3K/Akt/mTOR信号通路蛋白的表达。结果槲皮素以浓度-时间依赖性的方式抑制PC-3细胞活力,并诱导细胞凋亡;能够增加PC-3细胞自噬小泡和自噬小体的数量;能够升高PC-3细胞LC3-Ⅱ/LC3-Ⅰ及Beclin-1表达,同时降低磷酸化-PI3K、磷酸化-Akt和磷酸化-mTOR的表达。结论槲皮素可能是通过抑制PI3K/Akt/mTOR信号通路诱导PC-3细胞发生自噬。

Objective To investigate the effects of quercetin on cell viability,apoptosis,autophagy,and phosphatidylinositol 3-kinase(PI3K)/protein kinase B(Akt)/mammalian target of rapamycin(mTOR)signaling pathway in human prostate cell carcinoma PC-3 cells.Methods PC-3 cells were cultured in vitro,and cell viability was detected by CCK-8.Apoptosis was detected by TUNEL staining.Autophagy vesicle was observed by acridine orange staining.Autophagosomes was observed by GFP-LC3 plasmid transfection analysis.Expressions of autophagy-related protein microtubule associated protein 1 light chain 3 fusion protein(LC3)and Beclin-1 and PI3K/Akt/mTOR signaling pathway protein were detected by Western blot analysis.Results Quercetin inhibited cell viability in a dose-time dependent manner and induced apoptosis.Quercetin increased the number of autophagy vesicles and autophagosomes in PC-3 cells.Quercetin increased the expressions of LC3-Ⅱ/LC3-Ⅰand Beclin-1 in PC-3 cells and decreased the expression of phosphorylated-PI3K,phosphorylated-Akt and phosphorylated-mTOR.Conclusion Quercetin may induce autophagy by inactivating PI3K/Akt/mTOR signaling pathway in PC-3 cells.