甘草查尔酮A通过PI3K/Akt/mTOR信号通路诱导肾癌细胞自噬的研究

Effect of licochalcone A on autophagy in renal cell carcinoma via PI3K/Akt/mTOR signaling pathway

研究甘草查尔酮A（licochalcone A,LCA）对肾癌细胞自噬的影响,并探讨其对磷脂酰肌醇3-激酶（PI3K）/蛋白激酶B（Akt）/哺乳动物雷帕霉素靶蛋白（m TOR）信号通路的调控作用。实验以肾癌细胞系786-O,769-P细胞为研究对象,采用MTT检测细胞增殖;Transwell法检测细胞迁移和侵袭;吖啶橙（acridine orange,AO）染色观察细胞自噬状态;Ad-GFP-LC3转染实验观察细胞中绿色点状聚集的自噬小体;Western blot法检测自噬相关蛋白的表达,PI3K/Akt/m TOR信号通路的变化,以及抑制该通路后检测诱导自噬的变化。结果表明,LCA抑制细胞增殖呈时间-浓度依赖性,同时剂量依赖性地抑制细胞迁移和侵袭;LCA能够诱导细胞内酸性自噬泡和自噬小体的增多;LCA可明显诱导LC3-Ⅱ,beclin 1,Atg5蛋白表达,降低p62蛋白表达,同时减少Akt,m TOR的磷酸化。使用PI3K/Akt抑制剂（LY294002）以及m TOR抑制剂（rapamycin,Rap）可促进LCA诱导自噬的发生。以上结果提示,LCA通过抑制PI3K/Akt/m TOR信号通路进而抑制肾癌细胞增殖、迁移、侵袭,并诱导肾癌细胞发生自噬。

To investigate the effect of licochalcone（ LCA） on autophagy in renal cell carcinoma（ RCC）,and further determine whether the mechanism is correlated with the phosphatidylinositol 3-kinase（ PI3 K）/Akt/mammalian target of m TOR pathway,RCC786-O and 769-P were used as study subjects. MTT assay was used to examine cell proliferation. The abilities of migration and invasion were detected by Transwell. The autophagy was observed under the fluorescence microscope through acridine orange staining. Green fluorescence spots were observed in Ad-GFP-LC3 transfection experiment. The protein expression was detected by Western blot. MTT assay results showed a dose and time-dependent cytotoxicity in the two cell lines treated with LCA. LCA inhibited migration and invasion in 786-O and 769-P cells. LCA increased the expression levels of LC3-Ⅱ,beclin 1,Atg5,and down-regulated the expression of p62. In addition,LCA inhibited the PI3 K/Akt/m TOR pathway. Furthermore,the inhibition of PI3 K/Akt by LY294002 or that of m TOR by rapamycin augmented LCA-induced autophagy. The findings demonstrated that LCA inhibited the proliferation,migration,invasion,and induced autophagy by inactivating PI3 K/Akt/m TOR signaling pathway in 786-O and 769-P cells.