Design, synthesis, and structure-activity relationship studies of triazolo-pyrimidine derivatives as WRN inhibitors for the treatment of MSI tumors

Eur J Med Chem. 2025 Jan 15:282:117039. doi: 10.1016/j.ejmech.2024.117039. Epub 2024 Nov 12.

Abstract

Werner syndrome RecQ helicase (WRN), a member of the RecQ helicase family, has recently been identified as a synthetic lethal target in microsatellite instability (MSI) tumors. The triazolo-pyrimidine compound HRO761 is the first WRN inhibitor to enter clinical trials, but research on this scaffold remains limited. Here, we designed a series of derivatives to systematically study the structure-activity relationship (SAR) of triazolo-pyrimidine scaffolds, leading to the discovery of compound S35. S35 exhibited excellent WRN helicase inhibitory activity (ADP-Glo kinase assay IC50 = 16.1 nM, fluorometric helicase assay IC50 = 23.5 nM). Additionally, S35 exhibited excellent cellular selectivity, with antiproliferative activity against multiple MSI cell lines (GI50 = 36.4-306 nM), while the GI50 values for multiple microsatellite stability (MSS) cell lines were greater than 20,000 nM. Furthermore, we observed that compound S35 induced DNA damage and caused G2/M cell cycle arrest in MSI cells, which did not occur in MSS cells. S35 demonstrated favorable oral pharmacokinetic properties, with oral administration resulting in dose-dependent tumor growth inhibition in the SW48 xenograft model. These findings provide a promising outlook for the development of WRN inhibitors for the treatment of MSI tumors.

Keywords: MSI tumors; Synthetic lethal; Triazolo-pyrimidine derivatives; WRN inhibitors.

MeSH terms

  • Animals
  • Antineoplastic Agents* / chemical synthesis
  • Antineoplastic Agents* / chemistry
  • Antineoplastic Agents* / pharmacology
  • Cell Line, Tumor
  • Cell Proliferation* / drug effects
  • Dose-Response Relationship, Drug
  • Drug Design*
  • Drug Screening Assays, Antitumor*
  • Enzyme Inhibitors / chemical synthesis
  • Enzyme Inhibitors / chemistry
  • Enzyme Inhibitors / pharmacology
  • Humans
  • Mice
  • Microsatellite Instability / drug effects
  • Molecular Structure
  • Pyrimidines* / chemical synthesis
  • Pyrimidines* / chemistry
  • Pyrimidines* / pharmacology
  • Structure-Activity Relationship
  • Triazoles* / chemical synthesis
  • Triazoles* / chemistry
  • Triazoles* / pharmacology
  • Werner Syndrome Helicase* / antagonists & inhibitors
  • Werner Syndrome Helicase* / metabolism

Substances

  • Pyrimidines
  • Werner Syndrome Helicase
  • Antineoplastic Agents
  • Triazoles
  • WRN protein, human
  • Enzyme Inhibitors