The role of the equatorial ligands for the redox behavior, mode of cellular accumulation and cytotoxicity of platinum(IV) prodrugs

Author(s)
Simone Göschl, Hristo Varbanov, Sarah Theiner, Michael Jakupec, Mathea Sophia Galanski, Bernhard Keppler
Abstract

The current study aims to elucidate the possible reasons for the significantly different pharmacological behavior of platinum(IV) complexes with cisplatin-, carboplatin- or nedaplatin-like cores and how this difference can be related to their main physicochemical properties. Chlorido-containing complexes are reduced fast (within hours) by ascorbate and are able to unwind plasmid DNA in the presence of ascorbate, while their tri- and tetracarboxylato analogs are generally inert under the same conditions. Comparison of the lipophilicity, cellular accumulation and cytotoxicity of the investigated platinum compounds revealed the necessity to define new structure-property/activity relationships (SPRs and SARs). The higher activity and improved accumulation of platinum(IV) complexes bearing Cl- in equatorial position cannot only be attributed to passive diffusion facilitated by their lipophilicity. Therefore, further platinum accumulation experiments under conditions where active/facilitated transport mechanisms are suppressed were performed. Under hypothermic conditions (4 degrees C), accumulation of dichloridoplatinum(IV) complexes is reduced down to 10% of the amount determined at 37 degrees C. These findings suggest the involvement of active and/or facilitated transport in cellular uptake of platinum(IV) complexes with a cisplatin-like core. Studies with ATP depletion mediated by oligomycin and low glucose partially confirmed these observations, but their feasibility was severely limited in the adherent cell culture setting. (C) 2016 Elsevier Inc. All rights reserved.

Organisation(s)
Department of Inorganic Chemistry, NMR Centre
External organisation(s)
École polytechnique fédérale de Lausanne
Journal
Journal of Inorganic Biochemistry
Volume
160
Pages
264-274
No. of pages
11
ISSN
0162-0134
DOI
https://doi.org/10.1016/j.jinorgbio.2016.03.005
Publication date
07-2016
Peer reviewed
Yes
Austrian Fields of Science 2012
104003 Inorganic chemistry, 106002 Biochemistry, 301206 Pharmacology
Keywords
ASJC Scopus subject areas
Biochemistry, Inorganic Chemistry
Sustainable Development Goals
SDG 3 - Good Health and Well-being
Portal url
https://ucrisportal.univie.ac.at/en/publications/ff641fdd-6cd2-49a8-85e0-932210e2bc99