Adjusting the DNA Interaction and Anticancer Activity of Pt(II) N-Heterocyclic Carbene Complexes by Steric Shielding of the Trans Leaving Group

Julienne K. Muenzner, Tobias Rehm, Bernhard Biersack, Angela Casini, Inge A. M. de Graaf, Pawida Worawutputtapong, Awal Noor, Rhett Kempe, Viktor Brabec, Jana Kasparkova, Rainer Schobert*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

59 Citations (Scopus)

Abstract

Five platinum(LI) complexes bearing a (1,3-dibenzyl)imidazol-2-ylidene ligand but different leaving groups trans to it were examined for cytotomicity, DNA and cell cycle interference, vascular disrupting properties, and nephrotoxicity. The cytotoxicity of complexes 3a-c increased with the steric shielding of their leaving chloride ligand, and complex 3c, featuring two triphenylphosphanes, was the most efficacious, with submicromolar IC50 concentrations. Complexes 3a c interacted with DNA in electrophoretic mobility shift and ethidium bromide binding assays. The cationic complex 3c did not bind coordinatively to DNA but led to its aggregation, damage that is not amenable to the usual repair mechanisms. Accordingly, it arrested the cell cycle of melanoma cells in GI phase, whereas cis-dichlorido[(1,3-dibenzypimidazol-2-ylidene](dimethyl sulfoxide) platinum(II) 3a induced G2/M phase arrest. Complex 3c also disrupted the blood vessels in the chorioallantoic membrane of fertilized chicken eggs. Ex vivo studies using precision-cut tissue slices suggested the nephrotoxicities of 3a-c to be clinically manageable.

Original languageEnglish
Pages (from-to)6283-6292
Number of pages10
JournalJournal of Medicinal Chemistry
Volume58
Issue number15
DOIs
Publication statusPublished - 13-Aug-2015

Keywords

  • PLATINUM COMPLEXES
  • CANCER-CELLS
  • CISPLATIN
  • AGENTS
  • CONDENSATION
  • CYTOTOXICITY
  • MECHANISMS
  • ANTITUMOR
  • TOXICITY
  • BINDING

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