Shaanxi Key Laboratory of Phytochemistry and College of Chemistry and Chemical Engineering, Baoji University of Arts and Sciences, Baoji, 721013, China.
Department of Medical Technology, Qiandongnan Vocational and Technical College for Nationalities, Kaili, 556000, China.
Curr Pharm Biotechnol. 2022;23(14):1647-1657. doi: 10.2174/1389201023666211217151955.
Thioredoxin reductase (TrxR) plays vital role in regulating cellular redox balance as well as redox-mediated signal transduction. Accumulating evidence supports that overactivation of TrxR is closely related to tumorigenesis and that targeting TrxR ablation reverses the growth of numerous malignant tumors, making TrxR a promising target for cancer chemotherapy. Thus, the discovery and development of molecules as promising anticancer agents that target TrxR is of great significance. Oridonin was shown to inhibit TrxR activity, but the detailed cellular mechanism is largely unknown.
The study investigated the mechanism of action and underlying inhibitory properties of oridonin on TrxR in HeLa cells.
A covalent docking was performed to reveal the possible interaction between oridonin and TrxR by Schrödinger Software Suite. TrxR activity was determined by 5,5'-dithiobis-2- nitrobenzoic acid reduction assay and endpoint insulin reduction assay. Sulforhodamine B and colony formation assay were employed to assess the viability and growth of cells. Reactive oxygen species level was measured by probe 2', 7'-dichlorfluorescein diacetate, and dihydroethidium. Hoechst 33342 staining, caspase 3 activation, and fluorescein-5-isothiocyanate-conjugated Annexin V and propidium iodide double staining were used to evaluate apoptosis.
Here, we reported the oridonin as a potent inhibitor of TrxR. Inhibition of TrxR results in a decrease of thiols content and total glutathione, elevates reactive oxygen species levels, and finally promotes oxidative stress-mediated apoptosis of cancer cells.
Targeting TrxR by oridonin discloses a novel molecular mechanism underlying the biological action of oridonin and sheds light on developing oridonin as a potential tumor therapeutic agent.
硫氧还蛋白还原酶（TrxR）在调节细胞氧化还原平衡以及氧化还原介导的信号转导中起着至关重要的作用。越来越多的证据表明，TrxR 的过度激活与肿瘤发生密切相关，靶向 TrxR 消融可逆转许多恶性肿瘤的生长，使 TrxR 成为癌症化疗的有前途的靶点。因此，发现和开发针对 TrxR 的有前途的抗癌分子具有重要意义。冬凌草甲素已被证明能抑制 TrxR 的活性，但详细的细胞机制在很大程度上尚不清楚。
本研究旨在探讨冬凌草甲素在 HeLa 细胞中作用于 TrxR 的机制。
采用 Schrödinger 软件套件进行共价对接，以揭示冬凌草甲素与 TrxR 之间可能的相互作用。通过 5,5'-二硫代双-2-硝基苯甲酸还原试验和终点胰岛素还原试验测定 TrxR 活性。采用磺酰罗丹明 B 和集落形成试验评估细胞活力和生长。采用探针 2',7'-二氯荧光素二乙酸酯和二氢乙啶测量活性氧水平。采用 Hoechst 33342 染色、caspase 3 激活以及异硫氰酸荧光素-5-异硫氰酸酯结合 Annexin V 和碘化丙啶双重染色评估细胞凋亡。
本文报道冬凌草甲素是 TrxR 的一种有效抑制剂。抑制 TrxR 会导致巯基含量和总谷胱甘肽减少，增加活性氧水平，最终促进氧化应激介导的癌细胞凋亡。
冬凌草甲素靶向 TrxR 揭示了冬凌草甲素的生物学作用的新分子机制，并为将冬凌草甲素开发为潜在的肿瘤治疗剂提供了思路。
