Continuous administration of oxaliplatin, the most widely used first-line chemotherapy drug for colorectal cancer (CRC), eventually leads to drug resistance. Increasing the sensitivity of CRC cells to oxaliplatin is a key strategy to overcome this issue. Impairment of mitochondrial function is a pivotal mechanism determining the sensitivity of CRC to oxaliplatin. We discovered an inverse correlation between Translocase of Outer Mitochondrial Membrane 20 (TOMM20) and oxaliplatin sensitivity as well as an inverse relationship between TOMM20 and HECT, UBA, and WWE domain containing E3 ligase 1 (HUWE1) expression in CRC. For the first time, we demonstrated that HUWE1 ubiquitinates TOMM20 directly and also regulates TOMM20 degradation via the PARKIN-mediated pathway. Furthermore, we showed that overexpression of HUWE1 in CRC cells has a negative effect on mitochondrial function, including the generation of ATP and maintenance of mitochondrial membrane potential, leading to increased production of ROS and apoptosis. This effect was amplified when cells were treated simultaneously with oxaliplatin. Our study conclusively shows that TOMM20 is a novel target of HUWE1. Our findings indicate that HUWE1 plays a critical role in regulating oxaliplatin sensitivity by degrading TOMM20 and inducing mitochondrial damage in CRC.

奥沙利铂是结直肠癌（CRC）使用最广泛的一线化疗药物，持续给药最终会导致耐药性。提高CRC细胞对奥沙利铂的敏感性是克服这一问题的关键策略。线粒体功能损伤是决定CRC对奥沙利铂敏感性的关键机制。我们发现线粒体外膜转位酶 20 (TOMM20) 与奥沙利铂敏感性之间存在负相关，以及 TOMM20 与 CRC 中含有 E3 连接酶 1 (HUWE1) 表达的 HECT、UBA 和 WWE 结构域之间存在负相关。我们首次证明 HUWE1 直接泛素化 TOMM20，并通过 PARKIN 介导的途径调节 TOMM20 降解。此外，我们发现结直肠癌细胞中 HUWE1 的过度表达对线粒体功能有负面影响，包括 ATP 的产生和线粒体膜电位的维持，导致 ROS 产生增加和细胞凋亡。当细胞同时用奥沙利铂处理时，这种效应会被放大。我们的研究最终表明 TOMM20 是 HUWE1 的新靶点。我们的研究结果表明，HUWE1 通过降解 TOMM20 并诱导 CRC 线粒体损伤，在调节奥沙利铂敏感性中发挥关键作用。