Gold(I) and Silver(I) Complexes with 2-Anilinopyridine-Based Heterocycles as Multitarget Drugs against Colon Cancer

Inorg Chem. 2020 Dec 7;59(23):17732-17745. doi: 10.1021/acs.inorgchem.0c02922. Epub 2020 Nov 18.

Abstract

A series of gold(I) and silver(I) derivatives with N- or S-donor ligands derived from 2-anilinopyridine has been synthesized and characterized. The mononuclear structure of [Au(L1)(PPh3)](TfO) (1a) and [Au(L2)(PPh3)](TfO) (1b) was confirmed by X-ray diffraction studies, as well as the dinuclear structure in the case of [Ag(TfO)(L1)]2 (4a). Most of the complexes are cytotoxic against a model of colorectal adenocarcinoma (Caco-2 cell line) and breast adenocarcinoma cancer cell lines (MCF-7). [Au(L1)(PPh3)](TfO) (1a) was able to induce caspases 8 and 3 activation, loss of mitochondrial membrane potential, and reactive oxygen species (ROS)-dependent cell death on Caco-2 cells upon 24 h incubation. In addition, the gold complex 1a produced a significant inhibition of the redox enzyme thioredoxin reductase as well as 20S proteasome. However, the silver(I) analogue, [Ag(TfO)(L1)(PPh3)] (2a), induced cell death independent of inhibition of thioredoxin reductase and 20S proteasome, triggered ROS-independent apoptosis mediated by caspase 8 and 3 activation, and loss of mitochondrial membrane potential, which points to a different mechanism of action for both derivatives, dependent on the metal center.

MeSH terms

  • Aniline Compounds / chemistry
  • Aniline Compounds / pharmacology*
  • Antineoplastic Agents / chemical synthesis
  • Antineoplastic Agents / chemistry
  • Antineoplastic Agents / pharmacology*
  • Cell Death / drug effects
  • Cell Proliferation / drug effects
  • Coordination Complexes / chemical synthesis
  • Coordination Complexes / chemistry
  • Coordination Complexes / pharmacology*
  • Dose-Response Relationship, Drug
  • Drug Screening Assays, Antitumor
  • Gold / chemistry
  • Gold / pharmacology*
  • Heterocyclic Compounds / chemical synthesis
  • Heterocyclic Compounds / chemistry
  • Heterocyclic Compounds / pharmacology*
  • Humans
  • Molecular Structure
  • Pyridines / chemistry
  • Pyridines / pharmacology*
  • Silver / chemistry
  • Silver / pharmacology*
  • Structure-Activity Relationship
  • Tumor Cells, Cultured

Substances

  • Aniline Compounds
  • Antineoplastic Agents
  • Coordination Complexes
  • Heterocyclic Compounds
  • Pyridines
  • Silver
  • Gold