线粒体功能障碍和代谢重编程可导致肝细胞癌（HCC）的发生和进展。铁氧还蛋白1（FDX1）是一种小型线粒体蛋白，最近的研究表明FDX1在肿瘤铜凋亡中发挥重要作用，但其在HCC中的作用仍然难以捉摸。在本研究中，我们旨在研究 FDX1 在 HCC 中的表达和新功能。首先在公开数据集中分析 FDX1 表达，并通过免疫组织化学、qRT-PCR 和 Western blot 进行验证。通过体外和体内实验来探索FDX1的功能。非靶向代谢组学和 RNA 测序用于确定分子机制。采用mRFP-GFP-LC3慢病毒转染、Mito-Tracker Red和Lyso-Tracker Green染色、透射电镜、流式细胞术、JC-1染色等分析线粒体自噬或ROS水平。采用水动力尾静脉注射（HTVi）和患者来源的类器官（PDO）模型来分析FDX1过表达的影响。FDX1表达在HCC组织中显着下调。 FDX1下调促进肝癌细胞体外增殖、侵袭和体内生长、转移。此外，FDX1影响HCC细胞的代谢并与自噬相关。然后我们证实 FDX1 缺乏会增加 HCC 细胞中 ROS 水平，激活线粒体自噬和 PI3K/AKT 信号通路。有趣的是，清除 ROS 会减弱 FDX1 下调的促肿瘤作用和线粒体自噬。 HTVi和PDO模型的结果均发现FDX1升高显着抑制HCC进展。此外，FDX1低表达与较短的生存期相关，是HCC患者预后的独立危险因素。我们的研究调查了FDX1在HCC中的新功能。 FDX1 的下调有助于代谢重编程，并导致 ROS 介导的线粒体自噬和 PI3K/AKT 信号通路的激活。 FDX1 是一种潜在的预后生物标志物，增加 FDX1 表达可能是抑制 HCC 进展的潜在治疗方法。版权所有 © 2024 作者。由 Elsevier B.V. 出版。保留所有权利。

Mitochondrial dysfunction and metabolic reprogramming can lead to the development and progression of hepatocellular carcinoma (HCC). Ferredoxin 1 (FDX1) is a small mitochondrial protein and recent studies have shown that FDX1 plays an important role in tumor cuproptosis, but its role in HCC is still elusive. In this study, we aim to investigate the expression and novel functions of FDX1 in HCC.FDX1 expression was first analyzed in publicly available datasets and verified by immunohistochemistry, qRT-PCR and Western blot. In vitro and in vivo experiments were applied to explore the functions of FDX1. Non-targeted metabolomics and RNA-sequencing were used to determine molecular mechanism. mRFP-GFP-LC3 lentivirus transfection, Mito-Tracker Red and Lyso-Tracker Green staining, transmission electron microscopy, flow cytometry, JC-1 staining, etc. were used to analyze mitophagy or ROS levels. Hydrodynamic tail vein injection (HTVi) and patient-derived organoid (PDO) models were used to analyze effect of FDX1 overexpression.FDX1 expression is significantly downregulated in HCC tissues. FDX1 downregulation promotes HCC cell proliferation, invasion in vitro and growth, metastasis in vivo. In addition, FDX1 affects metabolism of HCC cells and is associated with autophagy. We then confirmed that FDX1 deficiency increases ROS levels, activates mitophagy and the PI3K/AKT signaling pathway in HCC cells. Interestingly, scavenging ROS attenuates the tumor-promoting role and mitophagy of FDX1 downregulation. The results of HTVi and PDO models both find that FDX1 elevation significantly inhibits HCC progression. Moreover, low FDX1 expression is associated with shorter survival and is an independent risk factor for prognosis in HCC patients.Our research had investigated novel functions of FDX1 in HCC. Downregulation of FDX1 contributes to metabolic reprogramming and leads to ROS-mediated activation of mitophagy and the PI3K/AKT signaling pathway. FDX1 is a potential prognostic biomarker and increasing FDX1 expression may be a potential therapeutic approach to inhibit HCC progression.Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.