L. Kobylinska, I. Ivasechko, N. Skorohyd, R. Panchuk, N. Mitina, A. Zaichenko, R. Lesyk, S.G. Vari
Danylo Halitsky Lviv National Medical University,
Keywords: 4-thiazolidinones, polymeric nanocarrier, apoptosis, rat glioma C6 cells
Summary:Heterocyclic 4-thiazolidinone derivatives demonstrated high cytotoxic potential in vitro and low toxic effect in vivo. Although poor solubility in water is a serious obstacle in further application of the compounds in oncology for chemotherapy. Recently nanomaterials including biocompatible hydrophilic polymers have been proposed for encapsulation of anticancer drugs for drug delivery to target tumors. We aimed to study to make the water-insoluble 4-thiazolidinone derivatives water soluble complex with a PEG-containing polymeric nanocarrier (PNC) as potential chemotherapeutics and enhance their pro-apoptotic action towards rat glioma C6 cells. Methods. The 4-thiazolidinones derivatives used in this study (Les-3288, Les-3833 and Les-3882) were synthesized at the Department of Pharmaceutical, Organic and Bioorganic Chemistry of Danylo Halytsky Lviv National Medical University. The PNC was synthesized at the Department of Organic Chemistry of Lviv National Polytechnic University. PNC is a surface-active polymer of a comb-like structure that contains the hydrophilic polyethylene glycol chains grafted to the main hydrophobic chain. Mechanisms of antineoplastic effects of 4-thiazolidinone derivatives were investigated in in vitro using rat glioma C6 cells. Cell nativity, cell cycling pattern, Annexin V expression were evaluated, and DNA damage was estimated by DNA comet analysis. Results. The studied 4-thiazolidinone derivatives use apoptosis mechanisms for killing rat glioma C6 cells, confirmed by FACS analysis of these cells in pre-G1 stage, and the appearance of Annexin V positive C6 cells. Involvement of the apoptosis mechanisms in the anticancer effects of the 4-thiazolidinone derivatives were confirmed by DNA comet assay. At 3 h treatment of the tumor cells the complex Les-3833+PNC compared to the Les-3833 drug decreased the ratio of rat glioma C6 cells in “0” DNA comets and simultaneous increase in the ratio of “1”, “2” and “3” comets. At 6 h the complex Les-3833+PNC compared to Les-3833 drug a large increase observed in the ratio of “1” comets. Also, increase in the ratio of cells with the most expressed DNA damage (“4” comets) was detected, and a decreased in the ratios of “2” and “3” comets observed. DNA comet analysis revealed single-strand brakes in the nuclear DNA of treated glioma C6 cells. Although probably did not cause by the intercalation of the studied compounds into the DNA molecule. Conclusion. The Les-3288 and Les-3833 drugs and PEG-containing PNC complexes provided water solubility, at the same time enhanced their cytotoxic in rat glioma C6 cells. The cytotoxicity realized (1) by the apoptosis mechanisms, (2) by the FACS analysis, (3) by the appearance of the pre-G1 fraction in the treated cells and the Annexin V-single-positive cells.