Tag Archives: DNA damage

Effect of a novel thiazole derivative and its complex with a polymeric carrier on stability of DNA in human breast cancer cells

N. S. Finiuk1,2, O. Yu. Klyuchivska1, I. I. Ivasechko1,
N. E. Mitina3, Yu. V. Ostapiuk2, M. D. Obushak2,
O. S. Zaichenko3, A. M. Babsky2, R. S. Stoika1,2*

1Institute of Cell Biology, NAS of Ukraine, Lviv, Ukraine;
2Ivan Franko National University of Lviv, Lviv, Ukraine;
3Lviv Polytechnic National University, Lviv, Ukraine;
*e-mail: stoika.rostyslav@gmail.com

Received: 26 January 2021; Accepted: 2021

Thiazole derivatives are perspective antitumor compounds characterized by a broad range of bioactivity, while polymeric carriers are widely used to enhance the efficiency of biological action of drugs, improve their biocompatibility and water solubility. Previously, we identified that the thiazole-based derivative BF1 (N-(5-benzyl-1,3-thiazol-2-yl)-3,5-dimethyl-1-benzofuran-2-carboxamide) possessed differential toxicity towards targeted tumor cell lines. The aim of the present work was to investigate the action in vitro of BF1 and its complex with the polymeric carrier (PC) poly(PEGMA-co-DMM) (BF1-РС complex) towards human breast adenocarcinoma cells of the MDA-MB-231 and MCF-7 lines. DNA comet analysis, diphenylamine DNA fragmentation assay, gel retardation assay of plasmid DNA, DNA intercalation assay using methyl green dye and fluorescent microscopy were used to study the effects of BF1 on DNA stability in breast cancer cells. The ІС50 of cytotoxic action towards MDA-MB-231 cells was 26.5 ± 2.9 µМ for BF1, while the ІС50 for the BF1-PC complex was 6.9 ± 0.4 µМ, and the PC demonstrated low toxicity (ІС50 ˃ 50 µМ). The BF1-PC complex possessed higher toxicity towards MCF-7 cells than free BF1, with ІС50 of 9.6 ± 0.8 µМ and 15.8 ± 0.9 µМ, respectively. BF1 and BF1-PC induced an increase in the number of damaged cells of the MDA-MB-231 line with blebbing of plasma membrane, condensed chromatin and/or fragmented nucleus and micronuclei formation. Both BF1 and the BF1-PC complex induced single-strand breaks in DNA and its fragmentation in treated MDA-MB-231 cells. The studied compounds were not bound to plasmid DNA and did not intercalate into DNA molecules.

Apoptosis induction in human leukemia cells by novel 2-amino-5-benzylthiazole derivatives

N. S. Finiuk1,2, I. I. Ivasechko1, O. Yu. Klyuchivska1,
Yu. V. Ostapiuk3, V. P. Hreniukh2, Ya. R. Shalai2,
V. S. Matiychuk3, M. D. Obushak3,
A. M. Babsky2, R. S. Stoika1

1Institute of Cell Biology, National Academy of Sciences of Ukraine, Lviv;
2Ivan Franko National University of Lviv, Biology Faculty, Lviv, Ukraine;
3Ivan Franko National University of Lviv, Chemistry Faculty, Lviv, Ukraine;
e-mail: stoika@cellbiol.lviv.ua

Received: 21 December 2018; Accepted: 20 March 2019

Derivatives of 2-amino-5-benzylthiazole are heterocyclic pharmacophores that exhibit different pharmacological activities including anticancer action. The mechanisms of such action of these compounds are not clear. The aim of the present study was to investigate apoptosis induction, particularly DNA damage in human leukemia cells, by the novel synthesized thiazole derivatives ‒ 2,8-dimethyl-7-(3-trifluoromethyl-benzyl)pyrazolo[4,3-e]thiazolo[3,2-a]pyrimidin-4(2H)-one (compound 1) and 7-benzyl-8-methyl-2-propylpyrazolo[4,3-e]thiazolo[3,2-a]pyrimidin-4(2H)-one (compound 2). Western-blot analysis, DNA comet assay in alkaline conditions, diphenylamine DNA fragmentation assay, agarose gel retardation, and methyl green DNA intercalation assays were used to study the effects of the studied compounds in human leukemia cells. These compounds induced PARP1 and caspase 3 cleavage in the leukemia cells, also increased the level of pro-apoptotic Bim protein and the mitochondrion-specific EndoG nuclease, and decreased the level of the anti-apoptotic Bcl-2 protein. They caused DNA single-strand breaks and DNA fragmentation in the leukemia cells without direct DNA binding or DNA intercalation. Thus, novel 2-amino-5-benzylthiazole derivatives may be promising agents for apoptosis induction in the targeted human leukemia cells.