Conjugation of Organoruthenium(II) 3-(1H-Benzimidazol-2-yl)pyrazolo[3,4-b]pyridines and Indolo[3,2-d]benzazepines to Recombinant Human Serum Albumin: a Strategy To Enhance Cytotoxicity in Cancer Cells

Author(s)
Iryna Stepanenko, Angela Casini, Fabio Edafe, Maria Novak, Vladimir Arion, Paul J. Dyson, Michael Jakupec, Bernhard Keppler
Abstract

Following our strategy of coupling cyclin-dependent kinase (Cdk) inhibitors with organometallic moieties to improve their physicochemical properties and bioavailability, five organoruthenium complexes (1c-5c) of the general formula [RuCl(eta(6)-arene)(L)]Cl have been synthesized in which the arene is 4-formylphenoxyacetyl-eta(6)-benzylamide and L is a Cdk inhibitor [3-(1H-benzimidazol-2-yl)-1H-pyrazolo[3,4-b]pyridines (L1-L3) and indolo[3,2-d]benzazepines (L4 and L5)]. All of the compounds were characterized by spectroscopic and analytical methods. Upon prolonged standing (2-3 months) at room temperature, the dimethyl sulfoxide (DMSO) solutions of 1c and 2c-(HCl) afforded residues, which after recrystallization from EtOH and EtOH/H(2)O, respectively, were shown by X-ray diffraction to be cis,cis-[Ru(II)Cl(2)(DMSO)(2)(L1)]center dot H(2)O and mer-[Ru(II)Cl(DMSO)(3)(L2-H)]center dot H(2)O. Compound 5c, with a coordinated amidine unit, undergoes E/Z isomerization in solution. The antiproliferative activities and effects on the cell cycle of the new compounds were evaluated. Complexes 1c-5c are moderately cytotoxic to cancer cells (CH1, SW480, A549, A2780, and A2780cisR cell lines). Therefore, in order to improve their antiproliferative effects, as well as their drug targeting and delivery to cancer cells, 1c-5c were conjugated to recombinant human serum albumin, potentially exploiting the so-called "enhanced permeability and retention" effect that results in the accumulation of macromolecules in tumors. Notably, a marked increase in cytotoxicity of the albumin conjugates was observed in all cases.

Organisation(s)
Department of Inorganic Chemistry
External organisation(s)
École polytechnique fédérale de Lausanne
Journal
Inorganic Chemistry
Volume
50
Pages
12669-12679
No. of pages
11
ISSN
0020-1669
Publication date
2011
Peer reviewed
Yes
Austrian Fields of Science 2012
104003 Inorganic chemistry
Sustainable Development Goals
SDG 3 - Good Health and Well-being
Portal url
https://ucrisportal.univie.ac.at/en/publications/859ec731-1ec2-4428-ab9b-2499d469b6c9