TPP 相关的线粒体靶向铜（II）配合物通过 ROS 介导的 Drp1 激活诱导肝癌细胞中 p53 依赖性凋亡。

BACKGROUND: In recent years, copper complexes have gradually become the focus of potential anticancer drugs due to their available redox properties and low toxicity. In this study, a novel mitochondrion-targeting copper (II) complex, [Cu (ttpy-tpp)Br] Br (simplified as CTB), is first synthesized by our group. CTB with tri-phenyl-phosphine (TPP), a targeting and lipophilic group, can cross the cytoplasmic and mitochondrial membranes of tumor cells. The present study aims to investigate how CTB affects mitochondrial functions and exerts its anti-tumor activity in hepatoma cells. METHODS: Multiple molecular experiments including Flow cytometry, Western blot, Immunofluorescence, Tracker staining, Transmission Electron Microscopy and Molecular docking simulation were used to elucidate the underlying mechanisms. Human hepatoma cells were subcutaneously injected into right armpit of male nude mice for evaluating the effects of CTB in vivo. RESULTS: CTB induced apoptosis via collapse of mitochondrial membrane potential (MMP), ROS production, Bax mitochondrial aggregation as well as cytochrome c release, indicating that CTB-induced apoptosis was associated with mitochondrial pathway in human hepatoma cells. Mechanistic study revealed that ROS-related mitochondrial translocation of p53 was involved in CTB-mediated apoptosis. Simultaneously, elevated mitochondrial Drp1 levels were also observed, and interruption of Drp1 activation played critical role in p53-dependent apoptosis. CTB also strongly suppressed the growth of liver cancer xenografts in vivo. CONCLUSION: In human hepatoma cells, CTB primarily induces mitochondrial dysfunction and promotes accumulation of ROS, leading to activation of Drp1. These stimulation signals accelerate mitochondrial accumulation of p53 and lead to the eventual apoptosis. Our research shows that CTB merits further evaluation as a chemotherapeutic agent for the treatment of Hepatocellular carcinoma (HCC).

背景：近年来，铜配合物因其具有氧化还原特性和低毒性而逐渐成为潜在抗癌药物的研究热点。本研究组首次合成了一种新型线粒体靶向铜（II）配合物[Cu（ttpy-tpp）Br]Br（简称 CTB）。带有三苯基膦（TPP）靶向和亲脂基团的 CTB 可以穿过肿瘤细胞的细胞质和线粒体膜。本研究旨在探讨 CTB 如何影响线粒体功能并在肝癌细胞中发挥其抗癌活性。

方法：采用流式细胞术、Western blot、免疫荧光、示踪剂染色、透射电子显微镜和分子对接模拟等多种分子实验，阐明其作用机制。用人肝癌细胞皮下注射到雄性裸鼠右腋窝下，评估 CTB 在体内的作用。

结果：CTB 通过线粒体膜电位（MMP）崩溃、ROS 产生、Bax 线粒体聚集以及细胞色素 c 释放诱导细胞凋亡，表明 CTB 诱导的细胞凋亡与人肝癌细胞中线粒体途径有关。机制研究表明，ROS 相关的 p53 线粒体易位参与了 CTB 介导的细胞凋亡。同时，还观察到线粒体 Drp1 水平升高，阻断 Drp1 激活在 p53 依赖性凋亡中起关键作用。CTB 还强烈抑制了体内肝癌异种移植瘤的生长。

结论：在人肝癌细胞中，CTB 主要诱导线粒体功能障碍和 ROS 积累，导致 Drp1 激活。这些刺激信号加速了 p53 的线粒体积累，并导致最终的细胞凋亡。我们的研究表明，CTB 作为治疗肝细胞癌（HCC）的化疗药物值得进一步评估。