Hu Jiangnan, Ghosh Chandrayee, Khaket Tejinder P, Yang Zhongyue, Tabdili Yasmine, Alamaw Eden D, Boufraqech Myriem, Dixon Scott J, Kebebew Electron
bioRxiv. 2025 Jun 27:2025.06.25.661418. doi: 10.1101/2025.06.25.661418.
While combination BRAF and MEK inhibitor treatment in -mutant cancers results in a response, treatment resistance and toxicity are common. Ferroptosis is an iron-dependent form of non-apoptotic cell death. BRAF inhibition has been associated with increased sensitivity to ferroptosis that is dependent on Glutathione Peroxidase 4 (GPX4).
, , and models of anaplastic thyroid cancer (ATC) were used to evaluate the anticancer activity of combination BRAF inhibition and ferroptosis induction.
Targeting key regulators of ferroptosis-GPX4, using RSL3 and ML162, and system X , using erastin-induced significant cell death in all ATC cell lines. Combination of dabrafenib and RSL3 synergistically increased cell death in -mutant ATC cells, and significantly inhibited cellular migration and colony formation. Mechanistically, lipid peroxidation, reactive oxygen species levels, and intracellular Fe increased significantly with combination treatment compared with each agent alone. Analysis of cell membrane iron importers and exporters showed significantly lower expression of ferroportin-1 (an iron exporter), suggesting the synergistic anticancer activity was due to increased iron accumulation and oxidative stress, leading to enhanced ferroptotic cell death. -mutant ATC cell spheroids showed synergistic cell death with dabrafenib and RSL3 treatment. , combination dabrafenib and ferroptosis induction (by targeting GPX4 using C18, and system X with IKE) significantly inhibited tumor growth in an orthotopic ATC mouse model. Additionally, dabrafenib-resistant -mutant ATC cells were more sensitive to ferroptosis induction than parental cells.
Dual targeting of and ferroptosis results in synergistic anticancer activity and overcomes resistance to BRAF inhibition.
虽然在BRAF基因 - 突变型癌症中联合使用BRAF和MEK抑制剂治疗会产生反应，但治疗耐药性和毒性很常见。铁死亡是一种铁依赖性的非凋亡性细胞死亡形式。BRAF抑制与对铁死亡的敏感性增加有关，这种敏感性依赖于谷胱甘肽过氧化物酶4（GPX4）。
使用间变性甲状腺癌（ATC）的细胞系、细胞球体和原位小鼠模型来评估联合BRAF抑制和诱导铁死亡的抗癌活性。
使用RSL3和ML162靶向铁死亡的关键调节因子GPX4，以及使用埃拉司亭靶向系统Xc铁摄取，在所有ATC细胞系中均诱导了显著的细胞死亡。达拉非尼与RSL3联合使用可协同增加BRAF - 突变型ATC细胞中的细胞死亡，并显著抑制细胞迁移和集落形成。从机制上讲，与单独使用每种药物相比，联合治疗使脂质过氧化、活性氧水平和细胞内铁显著增加。对细胞膜铁导入蛋白和输出蛋白的分析显示，铁转运蛋白1（一种铁输出蛋白）的表达显著降低，这表明协同抗癌活性是由于铁积累增加和氧化应激增强，导致铁死亡性细胞死亡增加。BRAF - 突变型ATC细胞球体在达拉非尼和RSL3治疗下显示出协同细胞死亡。此外，在原位ATC小鼠模型中，联合达拉非尼和诱导铁死亡（使用C18靶向GPX4，以及使用IKE靶向系统Xc）显著抑制了肿瘤生长。此外，达拉非尼耐药的BRAF - 突变型ATC细胞比亲本细胞对诱导铁死亡更敏感。
同时靶向BRAF和铁死亡可产生协同抗癌活性，并克服对BRAF抑制的耐药性。
