Biological activity of ruthenium and osmium arene complexes with modified paullones in human cancer cells

Author(s)
Gerhard Mühlgassner, Caroline Bartel, Wolfgang Schmid, Michael Jakupec, Vladimir Arion, Bernhard Keppler
Abstract

In an attempt to combine the ability of indolobenzazepines (paullones) to inhibit cyclin-dependent kinases (Cdks) and that of platinum-group metal ions to interact with proteins and DNA, ruthenium(II) and osmium(II) arene complexes with paullones were prepared, expecting synergies and an increase of solubility of paullones. Complexes with the general formula [(MCl)-Cl-II(eta(6)-p-cymene)L]Cl, where M = Ru (1.3) or Os (2, 4), and L=L-1 (1,2) or L-2 (3,4), L-1 = N-(9-bromo-7,12-dihydroindolo[3,2-d][1]-benzazepin-6(5H)-yliden-N'-(2-hydroxybenzylidene)azine and L-2= N-(9-bromo-7,12-dihydroindolo[3,2-d][1]benzazepin-6-yl)-N'-[3-hydroxy-5-(hydroxymethyl)-2-methylpyridin-4-yl-methylene]azinium chloride (L-2 center dot HCl), were now investigated regarding cytotoxicity and accumulation in cancer cells, impact on the cell cycle, capacity of inhibiting DNA synthesis and inducing apoptosis as well as their ability to inhibit Cdk activity. The MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrawlium bromide) assay yielded IC50 values in the nanomolar to low micromolar range. In accordance with cytotoxicity data, the BrdU assay showed that 1 is the most and 4 the least effective of these compounds regarding inhibition of DNA synthesis. Effects on the cell cycle are minor, although concentration-dependent inhibition of Cdk2/cyclin E activity was observed in cell-free experiments. Induction of apoptosis is most pronounced for complex 1, accompanied by a low fraction of necrotic cells, as observed by annexin V-fluorescein isothiocyanate/propidium iodide staining and flow cytometric analysis.

Organisation(s)
Department of Inorganic Chemistry
Journal
Journal of Inorganic Biochemistry
Volume
116
Pages
180-187
No. of pages
8
ISSN
0162-0134
DOI
https://doi.org/10.1016/j.jinorgbio.2012.06.003
Publication date
2012
Peer reviewed
Yes
Austrian Fields of Science 2012
104003 Inorganic chemistry, 301 Medical-Theoretical Sciences, Pharmacy
Sustainable Development Goals
SDG 3 - Good Health and Well-being
Portal url
https://ucrisportal.univie.ac.at/en/publications/eef34bee-c2fd-494b-bafa-65e121854626