Inhibition of Autophagy Promotes Salinomycin-Induced Apoptosis via Reactive Oxygen Species-Mediated PI3K/AKT/mTOR and ERK/p38 MAPK-Dependent Signaling in Human Prostate Cancer Cells.
Inhibition of Autophagy Promotes Salinomycin-Induced Apoptosis via Reactive Oxygen Species-Mediated PI3K/AKT/mTOR and ERK/p38 MAPK-Dependent Signaling in Human Prostate Cancer Cells.
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DOI：
10.3390/ijms18051088
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发表时间：
2017-05-18
影响因子：
5.6
通讯作者：
Ahn SC
中科院分区：
文献类型：
--
作者：
Kim KY;Park KI;Kim SH;Yu SN;Park SG;Kim YW;Seo YK;Ma JY;Ahn SC
近年来，自噬和细胞凋亡之间的相互作用已成为癌症化疗的重要因素。抑制自噬可能是通过持续暴露于化疗药物来改善化疗耐药癌症治疗的有效策略。然而，没有任何报告明确阐明了潜在的机制。因此，在这项研究中，我们评估了盐霉素，一种有前途的抗癌药物，是否诱导凋亡，并阐明了潜在的抗肿瘤机制，在化疗耐药的前列腺癌细胞。细胞活力测定、蛋白质印迹、膜联蛋白V/碘化丙啶测定、吖啶橙子（AO）染色、caspase-3活性测定、活性氧（ROS）产生和线粒体膜电位测定。我们的数据显示盐霉素改变了前列腺癌细胞对自噬的敏感性。用自噬抑制剂3-甲基腺嘌呤（3-MA）预处理可增强盐霉素诱导的细胞凋亡。值得注意的是，盐霉素减少前列腺癌细胞中AKT的磷酸化和雷帕霉素的磷酸化哺乳动物靶蛋白（mTOR）。用自噬和PI 3 K抑制剂LY 294002预处理，通过降低AKT和mTOR活性和抑制自噬来增强Salinomycin诱导的细胞凋亡。然而，PD 98059和SB 203580，细胞外信号调节激酶（ERK）和p38抑制剂预处理，抑制盐霉素诱导的自噬通过逆转ERK和p38的上调。此外，预处理N-乙酰-L-半胱氨酸（NAC），抗氧化剂，抑制活性氧的产生抑制盐霉素诱导的自噬。结果提示，盐霉素诱导细胞凋亡与ROS介导的自噬有关，其机制可能是通过调节PI 3 K/AKT/mTOR和ERK/p38 MAPK信号通路实现的。
Recently, the interplay between autophagy and apoptosis has become an important factor in chemotherapy for cancer treatment. Inhibition of autophagy may be an effective strategy to improve the treatment of chemo-resistant cancer by consistent exposure to chemotherapeutic drugs. However, no reports have clearly elucidated the underlying mechanisms. Therefore, in this study, we assessed whether salinomycin, a promising anticancer drug, induces apoptosis and elucidated potential antitumor mechanisms in chemo-resistant prostate cancer cells. Cell viability assay, Western blot, annexin V/propidium iodide assay, acridine orange (AO) staining, caspase-3 activity assay, reactive oxygen species (ROS) production, and mitochondrial membrane potential were assayed. Our data showed that salinomycin alters the sensitivity of prostate cancer cells to autophagy. Pretreatment with 3-methyladenine (3-MA), an autophagy inhibitor, enhanced the salinomycin-induced apoptosis. Notably, salinomycin decreased phosphorylated of AKT and phosphorylated mammalian target of rapamycin (mTOR) in prostate cancer cells. Pretreatment with LY294002, an autophagy and PI3K inhibitor, enhanced the salinomycin-induced apoptosis by decreasing the AKT and mTOR activities and suppressing autophagy. However, pretreatment with PD98059 and SB203580, an extracellular signal-regulated kinases (ERK), and p38 inhibitors, suppressed the salinomycin-induced autophagy by reversing the upregulation of ERK and p38. In addition, pretreatment with N-acetyl-l-cysteine (NAC), an antioxidant, inhibited salinomycin-induced autophagy by suppressing ROS production. Our results suggested that salinomycin induces apoptosis, which was related to ROS-mediated autophagy through regulation of the PI3K/AKT/mTOR and ERK/p38 MAPK signaling pathways.