Central Laboratory, Yanbian University Hospital, Yanji, China.
Key Laboratory of Pathobiology (Yanbian University), State Ethnic Affairs Commission, Yanji, China.
Apoptosis. 2024 Oct;29(9-10):1810-1823. doi: 10.1007/s10495-024-01973-2. Epub 2024 May 5.
Ferroptosis is a new programmed cell death characterized by iron-dependent lipid peroxidation. Targeting ferroptosis is considered a promising strategy for anti-cancer therapy. Recently, natural compound has gained increased attention for their advantage in cancer treatment, and the exploration of natural compounds as ferroptosis inducers offers a hopeful avenue for advancing cancer treatment modalities. Emodin is a natural anthraquinone derivative in many widely used Chinese medicinal herbs. In our previous study, we predicted that the anti-cancer effect of Emodin might related to ferroptosis by using RNA-seq in colorectal cancer (CRC). Thus, in this study, we aim to investigate the molecular mechanism underlying Emodin-mediated ferroptosis in CRC. Cell-based assays including CCK-8, colony formation, EdU, and Annexin V/PI staining were employed to assess Emodin's impact on cell proliferation and apoptosis. Furthermore, various techniques such as FerroOrange staining, C11-BODIPY 581/591 staining, iron, MDA, GSH detection assay and transmission electron microscopy were performed to examine the role of Emodin in ferroptosis. Additionally, specific NCOA4 knockdown cell lines were generated to elucidate the involvement of NCOA4 in Emodin-induced ferroptosis. Moreover, the effects of Emodin on ferroptosis were further confirmed through the application of inhibitors, including Ferrostatin-1, 3-MA, DFO, and PMA. As a results, Emodin inhibited proliferation and induced apoptosis in CRC cells. Emodin could decrease GSH content, xCT and GPX4 expression, meanwhile increasing ROS generation, MDA, and lipid peroxidation, and these effects could reverse by ferroptosis inhibitor, Ferostatin-1, iron chelator DFO, autophagy inhibitor 3-MA and NCOA4 silencing. Moreover, Emodin could inactivate NF-κb pathway, and PMA, an activator of NF-κb pathway could alleviate Emodin-induced ferroptosis in CRC cells. Xenograft mouse model also showed that Emodin suppressed tumor growth and induced ferroptosis in vivo. In conclusion, these results suggested that Emodin induced ferroptosis through NCOA4-mediated ferritinophagy by inactivating NF-κb pathway in CRC cells. These findings not only identified a novel role for Emodin in ferroptosis but also indicated that Emodin may be a valuable candidate for the development of an anti-cancer agent.
铁死亡是一种新的程序性细胞死亡方式，其特征是铁依赖性脂质过氧化。靶向铁死亡被认为是癌症治疗的一种有前途的策略。最近，天然化合物因其在癌症治疗方面的优势而受到越来越多的关注，探索天然化合物作为铁死亡诱导剂为推进癌症治疗方法提供了有希望的途径。大黄素是许多广泛使用的中药中的一种天然蒽醌衍生物。在我们之前的研究中，我们通过对结直肠癌（CRC）的 RNA-seq 预测大黄素的抗癌作用可能与铁死亡有关。因此，在这项研究中，我们旨在研究大黄素介导的 CRC 中铁死亡的分子机制。细胞实验包括 CCK-8、集落形成、EdU 和 Annexin V/PI 染色，用于评估大黄素对细胞增殖和凋亡的影响。此外，还使用 FerroOrange 染色、C11-BODIPY 581/591 染色、铁、MDA、GSH 检测试剂盒和透射电子显微镜等各种技术来研究大黄素在铁死亡中的作用。此外，还生成了特异性 NCOA4 敲低细胞系，以阐明 NCOA4 在大黄素诱导的铁死亡中的作用。此外，通过应用铁死亡抑制剂，包括 Ferrostatin-1、3-MA、DFO 和 PMA，进一步证实了大黄素对铁死亡的影响。结果表明，大黄素抑制 CRC 细胞的增殖并诱导其凋亡。大黄素可降低 GSH 含量、xCT 和 GPX4 表达，同时增加 ROS 生成、MDA 和脂质过氧化，这些作用可被铁死亡抑制剂 Ferrostatin-1、铁螯合剂 DFO、自噬抑制剂 3-MA 和 NCOA4 沉默逆转。此外，大黄素可以抑制 NF-κb 通路的激活，而 NF-κb 通路的激活剂 PMA 可以减轻 CRC 细胞中大黄素诱导的铁死亡。在体内，大黄素抑制肿瘤生长并诱导体内铁死亡。总之，这些结果表明，大黄素通过 NCOA4 介导的铁蛋白自噬，通过抑制 NF-κb 通路，诱导 CRC 细胞发生铁死亡。这些发现不仅确定了大黄素在铁死亡中的新作用，还表明大黄素可能是开发抗癌药物的有价值候选物。
