探究Sappanone A在癌症中诱导铁死亡的机制：NRF2/xCT/GPX4轴介导的线粒体功能障碍分析

非小细胞肺癌（NSCLC）是肺癌的主要亚型，包括鳞状细胞癌、腺癌和大细胞癌。与小细胞肺癌相比，NSCLC细胞的生长和分裂速度较慢，转移发生在较晚阶段。目前，化疗仍是该疾病的主要治疗方式。Sappanone A（SA）是一种从Caesalpinia sappan植物中提取的黄酮类化合物，具有抗肿瘤、调节氧化还原状态和抗炎作用。近年来，研究关注SA与线粒体途径在调控细胞死亡中的相互作用，通过Nrf-2/GPX-4/xCT轴调节。本文特别探讨SA通过调控线粒体自噬和线粒体生成，影响肿瘤细胞线粒体形态和结构的机制。研究主要利用第二代转录组测序数据和分子对接技术，阐明SA在调控肿瘤细胞程序性死亡中的作用。组学分析显示，SA处理显著靶向涉及氧化磷酸化、线粒体自噬、线粒体动力学及氧化应激的基因。进一步验证发现，Nrf-2/GPX4/xCT通路是SA治疗NSCLC的关键靶点。Nrf-2的敲低（si-Nrf-2）和过表达（ad-Nrf-2）均能不同程度调节SA的治疗效果。此外，GPX4/xCT基因的修饰显著影响SA对线粒体自噬、生成和能量代谢的调控作用。这些调控机制可能通过半胱天冬酶途径和铁死亡相关信号通路介导。分子生物学实验显示，SA干预进一步抑制FUNDC1在Tyr18的磷酸化，并下调TOM20的表达。SA处理导致PGC1α、Nrf-1和Tfam表达下降，减少线粒体呼吸和能量代谢。Nrf-2的过表达可以抵消SA对线粒体自噬和生成的调控作用。共聚焦显微镜进一步显示，SA增加线粒体碎片化，诱导线粒体途径介导的程序性死亡。然而，Nrf-2/GPX4/xCT通路的基因修饰显著改变SA对肿瘤细胞的调控效果。综上所述，SA被认为是一种具有潜力的NSCLC治疗药物。线粒体途径介导的凋亡和铁死亡可能是调控肿瘤细胞死亡的关键机制。靶向Nrf-2/GPX-4/xCT轴提供了一种新颖的治疗策略，有助于维持细胞微环境中的线粒体稳态。

Non-small cell lung cancer (NSCLC), a major subtype of lung cancer, encompasses squamous cell carcinoma, adenocarcinoma, and large cell carcinoma. Compared to small cell lung cancer, NSCLC cells grow and divide more slowly, and their metastasis occurs at a later stage. Currently, chemotherapy is the primary treatment for this disease. Sappanone A (SA) is a flavonoid compound extracted from the plant Caesalpinia sappan, known for its antitumor, redox-regulating, and anti-inflammatory properties. Recent studies have investigated the interaction of SA with mitochondrial pathways in regulating cell death through the Nrf-2/GPX-4/xCT axis. This study specifically explores the mechanism by which SA affects mitochondrial morphology and structure through the regulation of mitophagy and mitochondrial biogenesis in tumor cells. The study primarily utilizes second-generation transcriptomic sequencing data and molecular docking techniques to elucidate the role of SA in regulating programmed cell death in tumor cells. The omics results indicate that SA treatment significantly targets genes involved in oxidative phosphorylation, mitophagy, mitochondrial dynamics, and oxidative stress. Further findings confirmed that the Nrf-2/GPX4/xCT pathway serves as a crucial target of SA in the treatment of NSCLC. Knockdown of Nrf-2 (si-Nrf-2) and Nrf-2 overexpression (ad-Nrf-2) were shown to modulate the therapeutic efficacy of SA to varying degrees. Additionally, modifications to the GPX4/xCT genes significantly affected the regulatory effects of SA on mitochondrial autophagy, biogenesis, and energy metabolism. These regulatory mechanisms may be mediated through the caspase pathway and ferroptosis-related signaling. Molecular biology experiments have demonstrated that SA intervention further inhibits the phosphorylation of FUNDC1 at Tyr18 and downregulates TOM20 expression. SA treatment was found to reduce the expression of PGC1α, Nrf-1, and Tfam, resulting in a decrease in mitochondrial respiration and energy metabolism. Overexpression of Nrf-2 was shown to counteract the regulatory effects of SA on mitophagy and mitochondrial biogenesis. Confocal microscopy experiments further revealed that SA treatment increases mitochondrial fragmentation, subsequently inducing mitochondrial pathway-mediated programmed cell death. However, genetic modification of the Nrf-2/GPX4/xCT pathway significantly altered the regulatory effects of SA on tumor cells. In conclusion, SA has been identified as a promising therapeutic agent for NSCLC. The mitochondrial pathway-mediated apoptosis and ferroptosis may represent key mechanisms in regulating tumor cell death. Targeting the Nrf-2/GPX-4/xCT axis offers a novel therapeutic approach for maintaining mitochondrial homeostasis within the cellular microenvironment.