Bow Yung-Ding, Ko Ching-Chung, Chang Wen-Tsan, Chou Sih-Yan, Hung Chun-Tzu, Huang Jau-Ling, Tseng Chih-Hua, Chen Yeh-Long, Li Ruei-Nian, Chiu Chien-Chih
PhD Program in Life Sciences, College of Life Science, Kaohsiung Medical University, Kaohsiung, 80708, Taiwan.
Department of Medical Imaging, Chi Mei Medical Center, Tainan, 71004, Taiwan.
Cancer Cell Int. 2023 Aug 16;23(1):171. doi: 10.1186/s12935-023-02984-w.
The development of nonapoptotic programmed cell death inducers as anticancer agents has emerged as a cancer therapy field. Ferroptosis, ferrous ion-driven programmed cell death that is induced by redox imbalance and dysfunctional reactive oxygen species (ROS) clearance, is triggered during sorafenib and PD-1/PD-L1 immunotherapy. DFIQ, a quinoline derivative, promotes apoptosis by disrupting autophagic flux and promoting ROS accumulation. Our pilot experiments suggest that DFIQ participates in ferroptosis sensitization. Thus, in this study, we aimed to reveal the mechanisms of DFIQ in ferroptosis sensitization and evaluate the clinical potential of DFIQ.
We treated the non-small cell lung cancer (NSCLC) cell lines H1299, A549, and H460 with the ferroptosis inducer (FI) DFIQ and analyzed viability, protein expression, ROS generation, and fluorescence staining at different time points. Colocalization analysis was performed with ImageJ.
DFIQ sensitized cells to FIs such as erastin and RSL3, resulting in a decrease in IC of at least 0.5-fold. Measurement of ROS accumulation to explore the underlying mechanism indicated that DFIQ and FIs treatment promoted ROS accumulation and SOD1/SOD2 switching. Mitochondria, known ROS sources, produced high ROS levels during DFIQ/FI treatment. RSL3 treatment promoted mitochondrial damage and mitophagy, an autophagy-associated mitochondrial recycling system, and cotreatment with DFIQ induced accumulation of mitochondrial proteins, which indicated disruption of mitophagic flux. Thus, autophagic flux was measured in cells cotreated with DFIQ. DFIQ treatment was found to disrupt autophagic flux, leading to accumulation of damaged mitochondria and eventually inducing ferroptosis. Furthermore, the influence of DFIQ on the effects of clinical FIs, such as sorafenib, was evaluated, and DFIQ was discovered to sensitize NSCLC cells to sorafenib and promote ferroptosis.
This study indicates that DFIQ not only promotes NSCLC apoptosis but also sensitizes cells to ferroptosis by disrupting autophagic flux, leading to accumulation of dysfunctional mitochondria and thus to ferroptosis. Ferroptosis is a novel therapeutic target in cancer therapy. DFIQ shows the potential to enhance the effects of FIs in NSCLC and act as a potential therapeutic adjuvant in ferroptosis-mediated therapy.
开发非凋亡程序性细胞死亡诱导剂作为抗癌药物已成为一个癌症治疗领域。铁死亡是一种由亚铁离子驱动的程序性细胞死亡，由氧化还原失衡和功能失调的活性氧（ROS）清除所诱导，在索拉非尼和PD-1/PD-L1免疫治疗过程中会被触发。DFIQ是一种喹啉衍生物，通过破坏自噬流和促进ROS积累来促进细胞凋亡。我们的初步实验表明DFIQ参与铁死亡致敏。因此，在本研究中，我们旨在揭示DFIQ在铁死亡致敏中的机制，并评估DFIQ的临床潜力。
我们用铁死亡诱导剂（FI）DFIQ处理非小细胞肺癌（NSCLC）细胞系H1299、A549和H460，并在不同时间点分析细胞活力、蛋白质表达、ROS生成和荧光染色。使用ImageJ进行共定位分析。
DFIQ使细胞对如erastin和RSL3等铁死亡诱导剂敏感，导致半数抑制浓度（IC）至少降低0.5倍。通过测量ROS积累来探究潜在机制，结果表明DFIQ和铁死亡诱导剂处理促进了ROS积累以及超氧化物歧化酶1（SOD1）/超氧化物歧化酶2（SOD2）转换。线粒体作为已知的ROS来源，在DFIQ/铁死亡诱导剂处理期间产生了高水平的ROS。RSL3处理促进了线粒体损伤和线粒体自噬（一种与自噬相关的线粒体循环系统），与DFIQ共同处理诱导了线粒体蛋白的积累，这表明线粒体自噬流被破坏。因此，我们在与DFIQ共同处理的细胞中测量了自噬流。发现DFIQ处理会破坏自噬流，导致受损线粒体积累，最终诱导铁死亡。此外，评估了DFIQ对临床铁死亡诱导剂如索拉非尼效果的影响，发现DFIQ使NSCLC细胞对索拉非尼敏感并促进铁死亡。
本研究表明，DFIQ不仅促进NSCLC细胞凋亡，还通过破坏自噬流使细胞对铁死亡敏感，导致功能失调的线粒体积累，从而引发铁死亡。铁死亡是癌症治疗中的一个新的治疗靶点。DFIQ显示出增强铁死亡诱导剂在NSCLC中的效果并作为铁死亡介导治疗中潜在治疗佐剂的潜力。
