Triazolo-linked benzimidazoles as tubulin polymerization inhibitors and DNA intercalators: Design, synthesis, cytotoxicity, and docking studies

Arch Pharm (Weinheim). 2023 May;356(5):e2200449. doi: 10.1002/ardp.202200449. Epub 2023 Feb 17.

Abstract

A simple "click" protocol was employed in the quest of synthesizing 1,2,3-triazole-linked benzimidazoles as promising anticancer agents on various human cancer cell lines such as A549, HCT116, SK-Mel-28, HT-29, and MCF-7. Compound 12j demonstrated significant cytotoxic potential towards SK-Mel-28 cancer cells (IC50 : 4.17 ± 0.09 µM) and displayed no cytotoxicity (IC50 : > 100 µM) against normal human BEAS-2B cells inferring its safety towards normal healthy cells. Further to comprehend the underlying apoptosis mechanisms, AO/EB, dichlorodihydrofluorescein diacetate (DCFDA), and 4',6-diamidino-2-phenylindole (DAPI) staining were performed, which revealed the nuclear and morphological alterations. Compound 12j displayed impairment in cellular migration and inhibited colony formation. The annexin V binding assay and JC-1 were implemented to evaluate the scope of apoptosis and the loss of the mitochondrial transmembrane potential in SK-Mel-28 cells. Cell-cycle analysis revealed that compound 12j arrested the cells at the G2/M phase in a dose-dependent manner. Target-based assays established the inhibition of tubulin polymerization by 12j at an IC50 value of 5.65 ± 0.05 μM and its effective binding with circulating tumor DNA as a DNA intercalator. The detailed binding interactions of 12j with tubulin and DNA were examined by docking studies on PDB ID: 3E22 and DNA hexamer (PDB ID: 1NAB), respectively.

Keywords: DNA intercalation; apoptosis; click chemistry; tubulin inhibition.

MeSH terms

  • Antineoplastic Agents* / chemistry
  • Apoptosis
  • Cell Proliferation
  • DNA
  • Drug Screening Assays, Antitumor
  • Humans
  • Intercalating Agents / pharmacology
  • Molecular Docking Simulation
  • Polymerization
  • Structure-Activity Relationship
  • Tubulin / metabolism
  • Tubulin Modulators* / chemistry
  • Tubulin Modulators* / pharmacology

Substances

  • Tubulin Modulators
  • Intercalating Agents
  • Tubulin
  • Antineoplastic Agents
  • DNA