Thimerosal, a competitive thioredoxin reductase 1 (TrxR1) inhibitor discovered via high-throughput screening

Yicheng Ni; Zhongyuan Luo; Yixin Lv; Shuyuan Ma; Cheng Luo; Daohai Du

doi:10.1016/j.bbrc.2023.02.014

Thimerosal, a competitive thioredoxin reductase 1 (TrxR1) inhibitor discovered via high-throughput screening

Biochem Biophys Res Commun. 2023 Apr 2:650:117-122. doi: 10.1016/j.bbrc.2023.02.014. Epub 2023 Feb 7.

Authors

Yicheng Ni¹, Zhongyuan Luo², Yixin Lv³, Shuyuan Ma¹, Cheng Luo¹, Daohai Du⁴

Affiliations

¹ School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, 310024, China; Drug Discovery and Design Center, The Center for Chemical Biology, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.
² Drug Discovery and Design Center, The Center for Chemical Biology, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.
³ School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, 310024, China.
⁴ Drug Discovery and Design Center, The Center for Chemical Biology, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China. Electronic address: dhdu@simm.ac.cn.

PMID: 36780763
DOI: 10.1016/j.bbrc.2023.02.014

Abstract

Thioredoxin reductase 1 (TrxR1) is considered as an important anti-cancer drug target, inhibition of which can induce reactive oxygen species (ROS)-mediated apoptosis of human cancer cells. Here, we developed and optimized a high-throughput screening (HTS) assay based on enzyme kinetics for the discovery of TrxR1 inhibitors. By utilizing this assay, we performed a HTS for 2500 compounds from an in-house library against TrxR1. We found that a vaccine preservative, thimerosal, strongly inhibited TrxR1 in a competitive and reversible manner with an IC₅₀ of 24.08 ± 0.86 nM. In addition, we determined that thiomersal has an inhibitory effect on the proliferation of A549 lung cancer cell line, with a GI₅₀ of 6.81 ± 0.09 μM, slightly more potent than auranofin (GI₅₀ = 11.85 ± 0.56 μM). Furthermore, we showed by flow cytometer that thimerosal effectively increased the content of ROS in A549 cells. Therefore, our work provided a high-throughput screening assay to quickly and effectively discover TrxR1 inhibitors, identifying thiomersal as a novel TrxR1 inhibitor and chemical probe.

Keywords: Chemical probe; High-throughput screening; Thimerosal; Thioredoxin reductase 1 inhibitor.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Cell Line, Tumor
High-Throughput Screening Assays
Humans
Lung Neoplasms*
Reactive Oxygen Species / metabolism
Thimerosal
Thioredoxin Reductase 1* / metabolism
Thioredoxin-Disulfide Reductase / metabolism

Substances

Thioredoxin Reductase 1
Thimerosal
Reactive Oxygen Species
Thioredoxin-Disulfide Reductase