阿魏菇乙酸乙酯相三萜类化合物对食管癌Eca109细胞的增殖抑制及机制

目的：探讨阿魏菇乙酸乙酯相三萜类化合物（ethyl acetate fraction of Pleurotus ferulatus triterpenoid，PFTP-E）对食管癌Eca109细胞的生长抑制作用及可能机制。方法：采用3-(4,5-二甲基噻-2)-2,5-二苯基四氮唑溴盐法检测PFTP-E体外抑制Eca109细胞的增殖活性；Hoechst 33258染色观察细胞凋亡；流式细胞术检测PFTP-E对Eca109细胞的增殖、周期、凋亡、线粒体膜电位以及胞内活性氧水平变化的影响；免疫印迹法检测PFTP-E对细胞凋亡相关蛋白Bcl2、Bax、聚腺苷二磷酸-核糖聚合酶（poly ADP-ribose polymerase，PARP）、含半胱氨酸的天冬氨酸蛋白水解酶（cysteinyl aspartate specific proteinase，Caspase）3、Caspase9、细胞周期相关蛋白Cyclin B1、内质网应激相关蛋白真核起始因子2α（eukaryotic initiation factor 2α，eIF2α）、CHOP以及丝裂原活化蛋白激酶（mitogen-activated protein kinase，MAPK）信号通路相关蛋白表达的影响。结果：PFTP-E以时间和剂量依赖性抑制Eca109细胞的增殖，并将细胞周期阻滞在G2/M期，进而诱导Eca109细胞凋亡。PFTP-E可引起Eca109细胞线粒体膜电位崩溃并导致胞内活性氧水平升高。PFTP-E可上调细胞色素c、Bax、p-eIF2α、CHOP表达，下调Bcl2、Cyclin B1表达，显著增强剪切型PARP、Caspase3及Caspase9表达，同时诱导内质网应激，激活MAPK/JNK信号通路。结论：PFTP-E能有效诱导Eca109细胞凋亡，其抗肿瘤机制与线粒体损伤途径、周期阻滞、内质网应激等有关。

Inhibitory Effect and Mechanism of the Ethyl Acetate Fraction of Pleurotus ferulatus Triterpenoids on Proliferation of Esophageal Eca109 Cells

Objective: The study investigated the inhibitory effect of the ethyl acetate fraction of Pleurotus ferulatus triterpenoid (PFTP-E) on the proliferation of human esophageal carcinoma Eca109 cells and the possible underlying mechanism. Methods: Cell proliferation in vitro was detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Hoechst 33258 staining was used to observe cell apoptosis. Flow cytometry was used to assess cell proliferation, cycle, apoptosis, mitochondrial membrane potential and intracellular reactive oxygen species (ROS). The effects of PFTP-E on the expression of the apoptosis-related proteins Bcl2, Bax, poly ADP-ribose polymerase (PARP), caspase 3 and caspase 9; the cell cycle-related protein cyclin B1; the endoplasmic reticulum stress-related proteins eukaryotic initiation factor 2α (eIF2α) and CHOP; and mitogen-activated protein kinase (MAPK) signaling pathway-related proteins were detected by Western blot. Results: PFTP-E inhibited the proliferation of Eca109 cells in both a time and dose-dependent manner, blocked the cell cycle in G2/M phase and induced cell apoptosis. Meanwhile, PFTP-E decreased mitochondrial membrane potential and increased intracellular ROS production. In addition, PFTP-E could up-regulate the expression of cytochrome c, Bax, p-eIF2α and CHOP, down-regulate the expression of Bcl2 and cyclin B1, significantly increase cleaved-PARP, cleaved-caspase 3 and cleaved-caspase 9 expression levels, induce endoplasmic reticulum stress and activate the MAPK/JNK signaling pathway. Conclusion: PFTP-E can effectively induce apoptosis, and the underlying anti-tumor mechanism is related to mitochondrial damage, cell cycle block, endoplasmic reticulum stress.