Wang Ling, Sun Shibo, Liu Haowen, Zhang Qiuyu, Meng Yao, Sun Fan, Zhang Jianjun, Liu Haiyan, Xu Weiping, Ye Zhiwei, Zhang Jie, Sun Bingbing, Xu Jianqiang
Liaoning Key Laboratory of Chemical Additive Synthesis and Separation (CASS), School of Chemical Engineering, Ocean Technology and Life Science (CEOTLS) & Panjin Institute of Industrial Technology (PIIT), Dalian University of Technology, Panjin, China.
State Key Laboratory of Fine Chemicals, School of Chemical Engineering (CE), Dalian University of Technology, China.
FEBS J. 2024 Dec;291(23):5276-5289. doi: 10.1111/febs.17301. Epub 2024 Oct 21.
Thioredoxin reductase 1 (TXNRD1) has been identified as one of the promising chemotherapeutic targets in cancer cells. Therefore, a novel TXNRD1 inhibitor could accelerate chemotherapy in clinical anticancer research. In this study, glaucocalyxin A (GlauA), a natural diterpene extracted from Rabdosia japonica var. glaucocalyx, was identified as a novel inhibitor of TXNRD1. We found that GlauA effectively inhibited recombinant TXNRD1 and reduced its activity in gastric cancer cells without affecting the enzyme's expression level. Mechanistically, the selenocysteine residue (U498) of TXNRD1 was irreversibly modified by GlauA through a Michael addition. Additionally, GlauA formed a covalent adduct with glutathione (GSH) and disrupted cellular redox balance by depleting cellular GSH. The inhibition of TXNRD1 and depletion of GSH by GlauA conferred its cytotoxic effects in spheroid culture and Transwell assays in AGS cells. The disulfide stress induced cytotoxicity of GlauA could be mitigated by adding reducing agents, such as DTT and β-ME. Furthermore, the FDA-approval drug auranofin, a TXNRD1 inhibitor, triggered oligomerization of the cytoskeletal protein Talin-1 in AGS cells, indicating that inhibiting TXNRD1 triggered disulfide stress. In conclusion, this study uncovered GlauA as an efficient inhibitor of TXNRD1 and demonstrated the potential of TXNRD1 inhibition as an effective anticancer strategy by disrupting redox homeostasis and inducing disulfide stress.
硫氧还蛋白还原酶1（TXNRD1）已被确定为癌细胞中有前景的化疗靶点之一。因此，一种新型TXNRD1抑制剂可加速临床抗癌研究中的化疗进程。在本研究中，从毛萼香茶菜中提取的天然二萜——毛萼甲素（GlauA）被鉴定为一种新型TXNRD1抑制剂。我们发现，GlauA能有效抑制重组TXNRD1，并降低其在胃癌细胞中的活性，而不影响该酶的表达水平。从机制上讲，TXNRD1的硒代半胱氨酸残基（U498）通过迈克尔加成反应被GlauA不可逆地修饰。此外，GlauA与谷胱甘肽（GSH）形成共价加合物，并通过消耗细胞内GSH破坏细胞氧化还原平衡。GlauA对TXNRD1的抑制作用以及对GSH的消耗在AGS细胞的球体培养和Transwell实验中赋予了其细胞毒性作用。添加二硫苏糖醇（DTT）和β-巯基乙醇（β-ME）等还原剂可减轻GlauA诱导的二硫键应激细胞毒性。此外，美国食品药品监督管理局（FDA）批准的药物金诺芬，一种TXNRD1抑制剂，可引发AGS细胞中细胞骨架蛋白踝蛋白-1（Talin-1）的寡聚化，表明抑制TXNRD1会引发二硫键应激。总之，本研究发现GlauA是一种有效的TXNRD1抑制剂，并证明了通过破坏氧化还原稳态和诱导二硫键应激来抑制TXNRD1作为一种有效抗癌策略的潜力。
