目的:本研究旨在阐明索拉非尼诱导肝细胞癌(HCC)铁凋亡的潜在机制。
方法:使用体外和体内综合评估研究了双特异性磷酸酶4(DUSP4)在索拉非尼治疗的HCC中的作用,包括西方印迹,qRT-PCR,细胞活力测定,脂质活性氧(ROS)测定,免疫组织化学,和异种移植肿瘤小鼠模型。此外,无标记定量蛋白质组学用于鉴定与DUSP4相关的潜在蛋白质。
结果:我们的研究表明,抑制DUSP4表达会增加肝癌细胞对铁凋亡诱导物的敏感性,特别是索拉非尼和艾司汀,在体外和体内设置。此外,我们确定了DUSP4介导的关键铁凋亡相关标志物的调节,例如铁蛋白轻链(FTL)和铁蛋白重链1(FTH1)。值得注意的是,无标记定量蛋白质组学揭示了DUSP4对含YTH域1(YTHDC1)上苏氨酸残基T148的磷酸化。进一步的调查揭示了YTHDC1作为mRNA核出口调节剂的功能,是DUSP4的直接靶标,协调FTL和FTH1mRNA的亚细胞定位。重要的是,我们的研究强调了HCC中DUSP4表达升高与索拉非尼耐药之间的强相关性.
结论:我们的发现介绍了DUSP4作为索拉非尼诱导的铁凋亡的负调节因子。这一发现为开发针对HCC治疗量身定制的基于铁凋亡的治疗策略开辟了新的途径。
OBJECTIVE: This investigation aims to elucidate the mechanism underlying sorafenib-induced ferroptosis in hepatocellular carcinoma (HCC).
METHODS: The role of dual specificity phosphatase 4 (DUSP4) in sorafenib-treated HCC was investigated using comprehensive assessments both in vitro and in vivo, including Western blotting, qRT-PCR, cell viability assay, lipid reactive oxygen species (ROS) assay, immunohistochemistry, and xenograft tumor mouse model. Additionally, label-free quantitative proteomics was employed to identify potential proteins associated with DUSP4.
RESULTS: Our study revealed that suppression of DUSP4 expression heightens the susceptibility of HCC cells to ferroptosis inducers, specifically sorafenib and erastin, in both in vitro and in vivo settings. Furthermore, we identified DUSP4-mediated regulation of key ferroptosis-related markers, such as ferritin light chain (FTL) and ferritin heavy chain 1 (FTH1). Notably, label-free quantitative proteomics unveiled the phosphorylation of threonine residue T148 on YTH Domain Containing 1 (YTHDC1) by DUSP4. Further investigations unraveled that YTHDC1, functioning as an mRNA nuclear export regulator, is a direct target of DUSP4, orchestrating the subcellular localization of FTL and FTH1 mRNAs. Significantly, our study highlights a strong correlation between elevated DUSP4 expression and sorafenib resistance in HCC.
CONCLUSIONS: Our findings introduce DUSP4 as a negative regulator of sorafenib-induced ferroptosis. This discovery opens new avenues for the development of ferroptosis-based therapeutic strategies tailored for HCC treatment.