Structure-activity relationships of triazole-benzodioxine inhibitors of cathepsin X

Eur J Med Chem. 2020 May 1:193:112218. doi: 10.1016/j.ejmech.2020.112218. Epub 2020 Mar 12.

Abstract

Cathepsin X is a cysteine carboxypeptidase that is involved in various physiological and pathological processes. In particular, highly elevated expression and activity of cathepsin X has been observed in cancers and neurodegenerative diseases. Previously, we identified compound Z9 (1-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)-2-((4-isopropyl-4H-1,2,4-triazol-3-yl)thio)ethan-1-one) as a potent and specific reversible cathepsin X inhibitor. Here, we have explored the effects of chemical variations to Z9 of either benzodioxine or triazol moieties, and the importance of the central ketomethylenethio linker. The ketomethylenethio linker was crucial for cathepsin X inhibition, whereas changes of the triazole heterocycle did not alter the inhibitory potencies to a greater extent. Replacement of benzodioxine moiety with substituted benzenes reduced cathepsin X inhibition. Overall, several synthesized compounds showed similar or improved inhibitory potencies against cathepsin X compared to Z9, with IC50 values of 7.1 μM-13.6 μM. Additionally, 25 inhibited prostate cancer cell migration by 21%, which is under the control of cathepsin X.

Keywords: 1,2,4-Triazole; Anticancer drugs; Cathepsin X; Triazole-benzodioxine inhibitors.

MeSH terms

  • Antineoplastic Agents / chemical synthesis
  • Antineoplastic Agents / chemistry
  • Antineoplastic Agents / pharmacology*
  • Carboxypeptidases / antagonists & inhibitors*
  • Carboxypeptidases / metabolism
  • Cell Movement / drug effects
  • Cell Proliferation / drug effects
  • Cysteine Proteinase Inhibitors / chemical synthesis
  • Cysteine Proteinase Inhibitors / chemistry
  • Cysteine Proteinase Inhibitors / pharmacology*
  • Dioxanes / chemistry
  • Dioxanes / pharmacology*
  • Dose-Response Relationship, Drug
  • Drug Screening Assays, Antitumor
  • Humans
  • Models, Molecular
  • Molecular Structure
  • PC-3 Cells
  • Recombinant Proteins / metabolism
  • Structure-Activity Relationship
  • Triazoles / chemistry
  • Triazoles / pharmacology*
  • Tumor Cells, Cultured

Substances

  • Antineoplastic Agents
  • Cysteine Proteinase Inhibitors
  • Dioxanes
  • Recombinant Proteins
  • Triazoles
  • Carboxypeptidases