Browsing by Subject "Cytotoxic"
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Item Open Access Activatable photosensitizers: agents for selective photodynamic therapy(Wiley-VCH Verlag, 2017) Li, X.; Kolemen, S.; Yoon, J.; Akkaya, E. U.Recent developments in the design of bifunctional and activatable photosensitizers rejuvenate the aging field of photodynamic sensitization and photodynamic therapy. While systematic studies have uncovered new dyes that can serve as potential photosensitizers, the most promising results have come from studies aimed at gaining precise control over the location and rate of cytotoxic singlet oxygen generation. As a consequence, higher selectivities and efficiencies in photodynamic treatment protocols are now within reach. This feature article highlights the variety of approaches that have been pursued to improve photodynamic therapy and to transform simple photosensitizers into smarter theranostic agents.Item Open Access Effects of biological compound Turkish propolis extract on breast cancer cells(2013) Uğurlu, DenizPropolis is a resinous compound which is collected from various plants then combined with wax and bee enzymes by worker bees. There are many studies conducted on propolis or its active components aiming to find new treatment possibilities in diverse research fields such as immunology, infectious diseases, allergy, diabetes, ulcers, and oncology. Chemical analysis indicated that propolis is a multicomponent mixture of various compounds with prevalence of flavonoids and phenolic acids. Therefore it is important to investigate the propolis extract mechanisms of action in order to predict possible cytotoxic and may be therapeutic effects for cancer. The most common propolis extract is ethanol extract of propolis (EEP) whereas Turkish researchers were able to extract the propolis with dimethyl sulfoxide (DMSO) which can maximize the penetration of compounds from propolis to the cells as well as DMSO is a good solvent for flavonols (one of the most common compound in propolis). There are many studies conducted on propolis or its active components for treatment of cancer which reveals the potential of this biological compound in the development of novel anti-cancerous agents. However, anti-cancer activity of DMSO extract of Turkish propolis (DEP) on human breast cancer has not been investigated yet. The aim of this study was to investigate the anti-cancer effects of DMSO extract of Turkish propolis (DEP) on cancer cells. Inhibitory effects of propolis extracts collected from different regions of Turkey were analyzed on the growth of the human breast carcinoma cells. Two different propolis extracts were used to determine their cytotoxic effects of breast carcinoma cell lines using SRB staining and IC50 values were determined. The results showed that propolis is cytotoxic in dose-dependent manner (IC50 value of diverse from 25 ug/ml to 123 ug/ml). Real time monitoring (xCELLigence system) of propolis treated cells confirmed the cytotoxic effect of propolis, since increasing concentrations of propolis decreased the cell number in a dose- and cell line- dependent way. Furthermore, propolis treatment induces apoptosis in breast carcinoma cell lines. Propolis treated cells changed their adherent morphology to round cells and detached from the surface. Hoechst 33258 staining of propolis treated cells revealed the increasing number of cells displays DNA condensation. PARP-1, a 116 kDa nuclear enzyme, is cleaved in fragments of 89 and 24 kDa during apoptosis. Western blot analysis was performed to detect the PARP-1 cleavage in propolis treated cells. Decrease in the full-length PARP-1 protein levels supports our hypothesis that propolis shows its cytotoxic effect at least partially through induction of apoptosis. The effect of propolis on cell cycle was analyzed with flow cytometer after staining the cells with Propidium iodide (PI). Increase in the G2/M cell cycle arrest was observed in propolis treated cells compare to control DMSO treated MDA-MB-231 cells. In addition to cytotoxic effects, in vitro wound healing assay revealed that propolis treated MDA-MB-231 cells shows delayed invasion of the cells to the denuded area when compared to the DMSO control cells. In conclusion, propolis showed a cytotoxic effect on breast carcinoma cell lines by inducing apoptosis, G2/M arrest as well as delaying the invasion capacity of the cells which makes it a potent anti-tumorigenic compound that may be useful in cancer chemoprevention or therapy.Item Open Access In vitro biocompatibility of plasma-aided surface-modified 316L stainless steel for intracoronary stents(Institute of Physics Publishing, 2010) Bayram, C.; Mizrak, A.K.; Aktürk, S.; Kurşaklioǧlu H.; Iyisoy, A.; Ifran, A.; Denkbaş, E.B.316L-type stainless steel is a raw material mostly used for manufacturing metallic coronary stents. The purpose of this study was to examine the chemical, wettability, cytotoxic and haemocompatibility properties of 316L stainless steel stents which were modified by plasma polymerization. Six different polymeric compounds, polyethylene glycol, 2-hydroxyethyl methacrylate, ethylenediamine, acrylic acid, hexamethyldisilane and hexamethyldisiloxane, were used in a radio frequency glow discharge plasma polymerization system. As a model antiproliferative drug, mitomycin-C was chosen for covalent coupling onto the stent surface. Modified SS 316L stents were characterized by water contact angle measurements (goniometer) and x-ray photoelectron spectroscopy. C1s binding energies showed a good correlation with the literature. Haemocompatibility tests of coated SS 316L stents showed significant latency (t-test, p < 0.05) with respect to SS 316L and control groups in each test. © 2010 IOP Publishing Ltd.Item Open Access Near-IR absorbing BODIPY derivatives as glutathione-activated photosensitizers for selective photodynamic action(Wiley-VCH Verlag, 2014) Turan, I. S.; Cakmak, F. P.; Yildirim, D. C.; Cetin Atalay, R.; Akkaya, E. U.Enhanced spatiotemporal selectivity in photonic sensitization of dissolved molecular oxygen is an important target for improving the potential and the practical applications of photodynamic therapy. Considering the high intracellular glutathione concentrations within cancer cells, a series of BODIPY-based sensitizers that can generate cytotoxic singlet oxygen only after glutathione-mediated cleavage of the electron-sink module were designed and synthesized. Cell culture studies not only validate our design, but also suggest an additional role for the relatively hydrophobic quencher module in the internalization of the photosensitizer.Item Open Access A novel thiazolidine compound induces caspase-9 dependent apoptosis in cancer cells(Elsevier, 2012) Onen-Bayram, F. E.; Durmaz, I.; Scherman, D.; Herscovici, J.; Cetin Atalay, R.The forward chemogenomics strategy allowed us to identify a potent cytotoxic thiazolidine compound as an apoptosis-inducing agent. Chemical structures were designed around a thiazolidine ring, a structure already noted for its anticancer properties. Initially, we evaluated these novel compounds on liver, breast, colon and endometrial cancer cell lines. The compound 3 (ALC67) showed the strongest cytotoxic activity (IC50 ∼5 μM). Cell cycle analysis with ALC67 on liver cells revealed SubG1/G1 arrest bearing apoptosis. Furthermore we demonstrated that cytotoxicity of this compound was due to the activation of caspase-9 involved apoptotic pathway, which is death receptor independent. © 2012 Elsevier Ltd. All rights reserved.