Division of Radiation Biomedical Research, Korea Institute of Radiological and Medical Sciences, Seoul, 139-706, Korea.
Exp Mol Med. 2020 Oct;52(10):1730-1743. doi: 10.1038/s12276-020-00511-9. Epub 2020 Oct 12.
Peroxisome proliferator-activated receptor gamma (PPARɣ) agonists exert powerful anticancer effects by suppressing tumor growth. In this study, we developed PPZ023 (1-(2-(ethylthio)benzyl)-4-(2-methoxyphenyl)piperazine), a novel PPAR ligand candidate, and investigated the underlying signaling pathways in both non-small-cell lung cancer (NSCLC) and radio-resistant NSCLC cells. To identify whether PPZ023 has anticancer effects in NSCLC and radioresistant NSCLC cells, we performed WST-1, LDH, Western blot, and caspase-3 and -9 activity assays. Furthermore, we isolated exosomes from PPZ023-treated NSCLC cells and studied cell death signaling. PPZ023 reduces cell viability and increases LDH cytotoxicity and caspase-3 activity in NSCLC cells. PPZ023 induces cell death by generating reactive oxygen species (ROS) and triggering mitochondrial cytochrome c release. PPZ023 treatment causes cell death via the PERK-eIF2α-CHOP axis in both NSCLC cell lysates and exosomes, and PERK and CHOP knockdown significantly blocks ER stress-mediated apoptosis by reducing cleaved caspase-3. Interestingly, diphenyleneiodonium (DPI, a Nox inhibitor) inhibits PPZ023-induced cell death via ER stress, and PPARɣ knockdown inhibits PPZ023-induced ROS, ER stress, and cell death. Moreover, PPZ023, in combination with radiation, causes synergic cell death via exosomal ER stress in radioresistant NSCLC cells, indicating that PPZ023/radiation overcomes radioresistance. Taken together, our results suggest that PPZ023 is a powerful anticancer reagent for overcoming radioresistance.
过氧化物酶体增殖物激活受体 γ（PPARγ）激动剂通过抑制肿瘤生长发挥强大的抗癌作用。在这项研究中，我们开发了一种新型的 PPAR 配体候选物 PPZ023（1-（2-（乙基硫代）苄基）-4-（2-甲氧基苯基）哌嗪），并研究了其在非小细胞肺癌（NSCLC）和放射抗性 NSCLC 细胞中的潜在信号通路。为了确定 PPZ023 是否对 NSCLC 和放射抗性 NSCLC 细胞具有抗癌作用，我们进行了 WST-1、LDH、Western blot 和 caspase-3 和 -9 活性测定。此外，我们从 PPZ023 处理的 NSCLC 细胞中分离出外泌体，并研究了细胞死亡信号。PPZ023 降低 NSCLC 细胞的活力并增加 LDH 细胞毒性和 caspase-3 活性。PPZ023 通过产生活性氧（ROS）并触发线粒体细胞色素 c 释放来诱导细胞死亡。PPZ023 在 NSCLC 细胞裂解物和外泌体中的 PERK-eIF2α-CHOP 轴中引起细胞死亡，PERK 和 CHOP 敲低通过减少裂解的 caspase-3 显著阻断 ER 应激介导的细胞凋亡。有趣的是，二苯并碘（DPI，一种 Nox 抑制剂）通过 ER 应激抑制 PPZ023 诱导的细胞死亡，而 PPARγ 敲低抑制 PPZ023 诱导的 ROS、ER 应激和细胞死亡。此外，PPZ023 与辐射联合使用可通过放射抗性 NSCLC 细胞中的外泌体 ER 应激引起协同细胞死亡，表明 PPZ023/辐射克服了放射抗性。总之，我们的研究结果表明，PPZ023 是克服放射抗性的强大抗癌试剂。
