Shiyan Key Laboratory of Natural Medicine Nanoformulation Research, Hubei Key Laboratory of Embryonic Stem Cell Research, School of Basic Medical Sciences, Hubei University of Medicine, Renmin Road No. 30, Shiyan, 442000, Hubei, China.
Department of General Surgery, Taihe Hospital, Hubei University of Medicine, Renmin South Road No. 32, Shiyan, 442000, Hubei, China.
J Cancer Res Clin Oncol. 2024 Oct 14;150(10):460. doi: 10.1007/s00432-024-05974-1.
Chemotherapy for colorectal cancer (CRC) urgently needs low-toxicity and highly effective phytomedicine. Cepharanthine (Cep) shown to have multiple anti-tumor effects, including colorectal cancer, whose pivotal mechanisms are not fully understood. Herein, the present work aims to reveal the impact of Cep on the mitochondrial and anti-injury functions of CRC cells.
The TOM70/20 expression was screened by bioinformatic databases. SW480 cells were utilized as the colorectal cancer cell model. The expression of TOM70/20 and the downstream molecules were measured by western blots (WB). The ferroptosis was analyzed using Transmission electron microscopy (TEM), C11-BODIPY, PGSK, and DCFH-DA probes, wherein the detection was performed by flow cytometry and laser confocal microscopy. The anti-cancer efficacy was conducted by CCK-8 and Annexin-V/PI assay. The rescue experiments were carried out using Fer-1 and TOM70 plasmid transfection.
Bioinformatic data identified TOM20 and TOM70 were highly expressed in colorectal cancer, which could be down-regulated by Cep. Further findings disclosed that Cep treatment destroyed the mitochondria and inactivated the NRF2 signaling pathway, an essential pathway for resistance to ferroptosis, thereby promoting reactive oxygen species (ROS) generation in CRC cells. As a result, prominent ferroptosis could be observed in CRC cells in response to Cep, which thereby led to the reduced cell viability of cancer cells. On the contrary, recovery of TOM70 dampened the Cep-elicited mitochondria damage, ferroptosis, and anti-cancer efficacy.
In summary, Cep-mediated TOM inhibition inactivates the NRF2 signaling pathway, thereby triggering ferroptosis and achieving an anti-colorectal cancer effect. The current study provides an innovative chemotherapeutic approach for colorectal cancer with phytomedicine.
结直肠癌（CRC）的化疗迫切需要低毒高效的植物药。水黄皮素（Cep）显示出多种抗肿瘤作用，包括结直肠癌，但其关键机制尚未完全阐明。本研究旨在揭示 Cep 对 CRC 细胞线粒体和抗损伤功能的影响。
通过生物信息学数据库筛选 TOM70/20 的表达。SW480 细胞被用作结直肠癌细胞模型。通过 Western blot（WB）测量 TOM70/20 和下游分子的表达。使用透射电子显微镜（TEM）、C11-BODIPY、PGSK 和 DCFH-DA 探针分析铁死亡，其中通过流式细胞术和激光共聚焦显微镜进行检测。使用 CCK-8 和 Annexin-V/PI 测定法进行抗癌功效测定。使用 Fer-1 和 TOM70 质粒转染进行挽救实验。
生物信息学数据表明 TOM20 和 TOM70 在结直肠癌中高表达，Cep 可下调其表达。进一步的研究结果表明，Cep 处理破坏了线粒体并使 NRF2 信号通路失活，这是抵抗铁死亡的重要途径，从而导致 CRC 细胞中活性氧（ROS）的产生。结果，Cep 处理后可在 CRC 细胞中观察到明显的铁死亡，从而导致癌细胞活力降低。相反，TOM70 的恢复减弱了 Cep 诱导的线粒体损伤、铁死亡和抗癌功效。
总之，Cep 介导的 TOM 抑制使 NRF2 信号通路失活，从而引发铁死亡并实现抗结直肠癌作用。本研究为结直肠癌的植物药治疗提供了一种创新的化疗方法。
