牛蒡子苷元通过抑制PI3-K/Akt信号通路诱导肝癌细胞凋亡

Arctigenin, a Natural Lignan Compound, Induces Apoptotic Death of Hepatocellular Carcinoma Cells via Suppression of PI3-K/Akt Signaling

目的探讨天然木脂素类化合物牛蒡子苷元对肝癌细胞生长的抑制作用及其可能机制。方法采用不同浓度的牛蒡子苷元处理Hep G2和Hep3B细胞,通过MTT法检测细胞增殖情况,流式细胞术检测细胞凋亡及细胞周期,免疫印迹检测细胞中caspase-9和caspase-3的活化情况以及抗凋亡蛋白的表达。进一步通过转染Akt质粒以及使用PI3K抑制剂,探讨牛蒡子苷元对肝癌细胞PI3K/Akt信号通路的影响。结果牛蒡子苷元能以浓度依赖性方式显著抑制肝癌细胞增殖并促进其凋亡,同时抑制肝癌细胞中PI3K/Akt信号通路活化,降低抗凋亡蛋白Bcl-x L、Mcl-1和survivin的表达,抑制m TOR和S6K的磷酸化;细胞过表达Akt活化蛋白后可抑制牛蒡子苷元的上述效应,而PI3K抑制剂联合作用可增强上述效应。结论牛蒡子苷元可通过抑制PI3K/Akt信号通路下调抗凋亡蛋白的表达进而促进肝癌细胞凋亡。

Objective To explore the effects of arctigenin, a natural lignan compound, on the growth of human hepatocellular carcinoma （HCC） cells and the possible mechanisms. Methods The HepG2 and Hep3B cells were treated with different concentrations of arctigenin. The MTF assay was applied to detect the cell proliferation of HCC cells. Flow cytometry was applied to detect the cell apoptosis and cell cy- cle, and Western blot was adopted to detect the expressions of caspase-3 and caspase-9 as well as the expressions of anti-apoptotic proteins in cells. Manipulating Akt signaling was used to determine its role in the action of aretigenin. Results Arctigenin significantly inhibited the proliferation and induce the apoptosis of HCC cells in a concentration-dependent manner. Arctigenin induced the activation of caspase-9 and caspase-3. Overexpression of a constitutively active Akt mutant blocked arctigenin-induced apoptosis. Comhinational treatment with arctigenin and the PI3K inhibitor LY294002 enhanced apoptosis significantly. Arctigenin reduced the expression of Bcl-xL, Mcl-I and sur- viving, and the phosphorylation of roTOR and S6K, which were significantly reversed by overexpression of constitutively-active Akt. Con- clusion Arctigenin could down-regulate the expressions of anti-apoptotic proteins and promote the apoptosis of hepatocellular carcinoma ceils by inactivating PI3-K/Akt signaling.