School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China.
J Toxicol Sci. 2024;49(9):399-408. doi: 10.2131/jts.49.399.
Nasopharyngeal carcinoma (NPC) originates from the nasopharynx epithelium, and luteolin is recognized as an important anti-cancer agent. This study investigated the effects of luteolin on ferroptosis in NPC cells. NPC cells were cultured and exposed to varying concentrations of luteolin. Cell viability, malondialdehyde (MDA) levels, superoxide dismutase (SOD) activity, glutathione (GSH) levels, Fe concentration, and glutathione peroxidase 4 (GPX4) protein level were assessed. Additionally, SRY-related high-mobility-group box 4 (SOX4) expression was measured. Subsequently, the binding of SOX4 to the growth differentiation factor-15 (GDF15) promoter and GDF15 mRNA levels were evaluated. The impact of the SOX4/GDF15 axis on luteolin-induced ferroptosis in NPC cells was assayed. Luteolin treatment induced cell ferroptosis, evidenced by decreased cell viability, increased MDA and Fe levels, and reduced SOD, GSH, and GPX4 levels. Furthermore, luteolin downregulated SOX4 expression, while overexpression of SOX4 reversed luteolin's pro-ferroptotic effects in NPC cells. SOX4 was found to up-regulate GDF15 transcription by directly binding to its promoter. Conversely, overexpression of GDF15 mitigated the ferroptotic effects induced by luteolin in NPC cells. Therefore, luteolin induces ferroptosis in NPC cells via modulation of the SOX4/GDF15 axis. In conclusion, luteolin reduces the binding of SOX4 to the GDF15 promoter by suppressing SOX4 expression, thereby down-regulating GDF15 transcription levels and inducing ferroptosis in NPC cells.
鼻咽癌(NPC)来源于鼻咽部上皮,木樨草素被认为是一种重要的抗癌药物。本研究探讨了木樨草素对 NPC 细胞铁死亡的影响。培养 NPC 细胞并使其暴露于不同浓度的木樨草素中。评估细胞活力、丙二醛(MDA)水平、超氧化物歧化酶(SOD)活性、谷胱甘肽(GSH)水平、铁浓度和谷胱甘肽过氧化物酶 4(GPX4)蛋白水平。此外,还测量了性别决定区 Y 相关高迁移率族盒 4(SOX4)的表达。随后,评估了 SOX4 与生长分化因子 15(GDF15)启动子的结合以及 GDF15 mRNA 水平。测定了 SOX4/GDF15 轴对 NPC 细胞中木樨草素诱导的铁死亡的影响。木樨草素处理诱导细胞铁死亡,表现为细胞活力降低,MDA 和 Fe 水平升高,SOD、GSH 和 GPX4 水平降低。此外,木樨草素下调 SOX4 表达,而过表达 SOX4 逆转了 NPC 细胞中木樨草素的促铁死亡作用。SOX4 被发现通过直接结合其启动子而上调 GDF15 的转录。相反,过表达 GDF15 减轻了 NPC 细胞中木樨草素诱导的铁死亡作用。因此,木樨草素通过调节 SOX4/GDF15 轴诱导 NPC 细胞发生铁死亡。总之,木樨草素通过抑制 SOX4 表达减少 SOX4 与 GDF15 启动子的结合,从而下调 GDF15 转录水平并诱导 NPC 细胞发生铁死亡。