Yang Zhiwen, Yuan Yichuan, Niu Yi, Zuo Dinglan, Liu Wenwu, Li Kai, Shi Yunxing, Qiu Zhiyu, Li Keren, Lin Zhu, Zhong Chengrui, Huang Zhenkun, He Wei, Guan Xinyuan, Yuan Yunfei, Zeng Weian, Qiu Jiliang, Li Binkui
State Key Laboratory of Oncology in South China and Collaborative Innovation Center for Cancer Medicine, Sun Yat-Sen University Cancer Center, Guangzhou, China.
Department of Anesthesiology, Sun Yat-Sen University Cancer Center, 651 Dongfeng Road East, Guangzhou, 510060, PR China.
Cell Oncol (Dordr). 2025 Apr;48(2):505-522. doi: 10.1007/s13402-024-01017-6. Epub 2024 Dec 9.
Sorafenib is a commonly used first-line kinase-targeted drug for advanced hepatocellular carcinoma (HCC) patients suffering from limited efficacy. Emerging evidence indicates that sorafenib exerts anti-cancer activity through the induction of ferroptosis in HCC cells, but the underlying mechanism is still unclear.
The whole transcriptome sequencing and bioinformatics analysis were used to screen for target genes. The expression and subcellular localization of regulatory factor X1 (RFX1) were determined through immunohistochemistry, immunofluorescence, PCR and western blot analyses. The impact of RFX1 on HCC cell growth was assessed using CCK8, colony formation assays, cell death assays, and animal experiments. Glutathione measurement, iron assay and lipid peroxidation detection assays were performed to investigate ferroptosis of HCC cells. The regulatory mechanism of RFX1 in HCC was investigated by sgRFX1, co-IP, ChIP and luciferase experiments. Immunohistochemical and survival analyses were performed to examine the prognostic significance of RFX1 in HCC.
In this study, we found that RFX1 promote ferroptosis in HCC cells. Further, we showed that sorafenib induces cell death through RFX1-mediated ferroptosis in HCC cells. The enhancing effect of RFX1 on HCC cell ferroptosis is largely dependent on inhibition of cystine/glutamate antiporter (system Xc-) activity through the BECN-SLC7A11 axis, where RFX1 directly binds to the promoter region of BECN1 and upregulates BECN1 expression. In addition, a STAT3-RFX1-BECN1 signalling loop was found to promote RFX1 expression in HCC cells.
Our study reveals a novel mechanism underlying sorafenib-induced HCC cell death.
索拉非尼是晚期肝细胞癌（HCC）患者常用的一线激酶靶向药物，但疗效有限。新出现的证据表明，索拉非尼通过诱导HCC细胞铁死亡发挥抗癌活性，但其潜在机制仍不清楚。
采用全转录组测序和生物信息学分析筛选靶基因。通过免疫组织化学、免疫荧光、PCR和蛋白质印迹分析确定调节因子X1（RFX1）的表达和亚细胞定位。使用CCK8、集落形成试验、细胞死亡试验和动物实验评估RFX1对HCC细胞生长的影响。进行谷胱甘肽测量、铁测定和脂质过氧化检测试验以研究HCC细胞的铁死亡。通过sgRFX1、免疫共沉淀、染色质免疫沉淀和荧光素酶实验研究RFX1在HCC中的调控机制。进行免疫组织化学和生存分析以检验RFX1在HCC中的预后意义。
在本研究中，我们发现RFX1促进HCC细胞铁死亡。此外，我们表明索拉非尼通过RFX1介导的HCC细胞铁死亡诱导细胞死亡。RFX1对HCC细胞铁死亡的增强作用很大程度上依赖于通过BECN-SLC7A11轴抑制胱氨酸/谷氨酸反向转运体（系统Xc-）活性，其中RFX1直接结合到BECN1的启动子区域并上调BECN1表达。此外，发现一个STAT3-RFX1-BECN1信号环促进HCC细胞中RFX1的表达。
我们的研究揭示了索拉非尼诱导HCC细胞死亡的新机制。
