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Cytotoxic and apoptotic effects of the combination of palladium (II) 5,5-diethylbarbiturate complex with bis(2-pyridylmethyl)amine and curcumin on non small lung cancer cell lines
(Pergamon-Elsevier Science Ltd, 2017) Tunç, Duygu; Dere, Egemen; Karakaş, Didem; Cevatemre, Buse; Yılmaz, Veysel Turan; Ulukaya, Engin
Metal-based chemotherapeutics such as cisplatin are widely used treatment of lung cancer which is the major cause of cancer-related mortality worldwide. Recent studies demonstrated that novel metal-based compounds have strong cytotoxic activity in a similar way as cisplatin. Therefore, metal-based compounds have been synthesized and investigated in order to determine their cytotoxic activities. It has been also reported curcumin, which has been derived from turmeric plant, has powerful cytotoxic effect on various cancer cell lines. In the light of these data, it has been investigated the cytotoxic effects of combination of curcumin (0.78-100 mu M) and palladium (II) 5,5-diethylbarbiturate complex with bis(2-pyridylmethyl)amine [Pd(II) complex] (0.39-50 mu M) against non small lung cancer cell lines, A549 and H1299. It has been found that combination of Pd(II) complex and curcumin enhanced the cytotoxic activity and apoptotic cell death at 48 h, compared to single use of each agent, only in H1299 cell line (combination index <1). Apoptosis was evident by annexin v staining positivity, increased caspase 3/7 activity and the presence of pyknotic nuclei. Pro-apoptotic genes of TNFRSFIOA and HRK were found to be involved in apoptotic cell death. In conclusion, the application of this combination may be regarded as a novel and effective approach for the treatment of lung cancer due to its promising cytotoxic and apoptotic effect. (C) 2017 Elsevier Ltd. All rights reserved.
Cytotoxic platinum(II) complexes derived from saccharinate and phosphine ligands: synthesis, structures, DNA cleavage, and oxidative stress-induced apoptosis
(Springer, 2020) İçsel, Ceyda; Yılmaz, Veysel T.; Cevatemre, Buse; Aygün, Muhittin; Ulukaya, Engin
A series of the structurally related platinum(II) saccharinate (sac) complexes with alkylphenylphosphines, namely cis-[Pt(sac)(2)(PPh2Me)(2)]center dot DMSO (1), cis-[Pt(sac)(2)(PPhMe2)(2)] (2), cis-[Pt(sac)(2)(PPh2Et)(2)] (3), and cis-[Pt(sac)(2)(PPhEt2)(2)]center dot 2DMSO (4), were synthesized and fully characterized; their structures were determined by X-ray crystallography. All the complexes were investigated for their anticancer potentials on three human cancer cells including A549 (lung), MCF-7 (breast), and HCT116 (colon) in addition to a noncancerous human bronchial epithelial cells (BEAS-2B). Specifically, 1 and 3 showed significant cytotoxic effects against MCF-7 and HCT116 cell lines in comparison to cisplatin, and were considered as the most potent ones in the series. The cytotoxic complexes were found to cleave DNA efficiently. In addition, the binding interactions of the complexes with DNA were confirmed by enzyme inhibition and molecular docking studies. Complexes 1 and 3 were capable of inducing apoptosis and arrested the cell cycle at the DNA synthesis (S) phase in MCF-7 cells. Furthermore, 1 and 3 caused the excessive generation of reactive oxygen species (ROS), leading to mitochondrial dysfunction and double-strand DNA breaks.
Enhanced cytotoxic activity of doxorubicin through the inhibition of autophagy in triple negative breast cancer cell line
(Elsevier Science Bv, 2017) Aydınlık, Şeyma; Erkısa, Merve; Cevatemre, Buse; Sarımahmut, Mehmet; Dere, Egemen; Arı, Ferda; Ulukaya, Engin
Background: The outcome of triple negative breast cancer is still poor and requires improvement with better therapy options. Autophagy has recently been shown to play a role in anticancer drug resistance. Therefore, we investigated if the effectiveness of doxorubicin was augmented by the inhibition of autophagy. Methods: MDA-MB-231 was used as a model cell line for triple negative breast cancer and 3-methyladenine was used as an inhibitor of autophagy. Cells were treated with 0.46-1.84 mu M doxorubicin and 2.5-10 mu M 3-methyladenine for 48 h. Cell death mode was examined with M30 and M65 ELISA assays. ROS level and LDH activity was examined and the cellular acidic compartment of cells was monitored by acridine orange staining. The expression of various autophagy and apoptosis related proteins/genes were evaluated with Western blotting and RT-qPCR respectively. Results: Synergism was observed between the compounds (CI value < 1.0). RT-qPCR analysis revealed that the combination resulted in a down-regulation of autophagy-related genes. Moreover, the combination resulted in a different cell death modality, upregulating necroptosis-related genes. This suggests that the mode of cell death may switch from apoptosis to necroptosis, which is a more severe form of cell death, when autophagy is inhibited. These results were further confirmed at protein level by Western blotting. Conclusion: Inhibition of autophagy seems to sensitize triple negative breast cancer cells to doxorubicin, warranting further in vivo studies for the proof of this concept. General significance: Autophagy has a key role in drug resistance in MDA-MB-231 cells. Therefore combinatorial approaches may effectively overcome resistance. (C) 2016 Elsevier B.V. All rights reserved.
Kalsitriol ve doksorubisin kombinasyonunun MCF7 üzerine olası anti kanser etkilerinin araştırılması
(DergiPark, 2018) Bildiren, Özge; Cevatemre, Buse; Ay, Ebru Nur; Özen, Güneş; Hepokur, Ceylan; Erkısa Genel, Merve; Ulukaya, Engin
Amaç: Bu çalışmada amacımız, belirli bir dozun üzerinde kardiyak yan etkileri oldukça fazla olan ve meme kanseri tedavisinde kullanılan kemoterapötiklerden doksorubisinin, tedavide kullanım miktarlarını azaltmayı ve etkinliğini arttırmayı sağlayan bir maddeyi saptamaktı. Etken madde olarak anti proliferatif etkisi olduğu düşünülen vitamin D analoglarından biri olan kalsitriol seçilmiş ve doksorubisin ile kombine tedavisinin, insan meme kanseri hücre hattı MCF-7 üzerine sitotoksik etkisinin saptanması amaçlanmıştır. Gereç ve Yöntem: MCF-7 insan meme kanseri hücre hattı kalsitriol ile muamele edilerek, gerçek zamanlı olarak, x-CELLigence cihazında 72 saat inkübasyona bırakıldı ve kalsitriolün anti-proliferatif optimum doz tespiti zamana bağlı hücre indeksi grafiği The xCELLigence Real-Time Cell Analysis (RTCA) software programı kullanılarak yapıldı. Kalsitriol optimum dozu ve doksorubisinin farklı dozlarının kombinasyonu MCF-7 hücre kültürü ile muamele edilerek sitotoksisite tayini için Sulforhodamine-B (SRB) uygulaması ve spektrofotometrik ölçüm uygulandı. Spektrofotometrik ölçüm sonuçları anlamlılık sonuçları için Student’s t-Testi ile değerlendirildi. Bulgular: MCF-7 hücrelerinin antiproliferative optimum kalsitriol doz tespiti zamana bağlı hücre indeksi grafiği RTCA software programı kullanılarak yapılmıştır. Sitotoksisite tayini için uygulanan SRB yöntemi sonucu elde edilen spektrofotometrik ölçüm sonuçları GraphPad Prism programı kullanılarak Student’s t-testi ile istatistiksel olarak değerlendirilmiştir. Kalsitriol optimum dozu 250 nM tespit edilmiştir. Doksorubisinin farklı dozları (1,84 µM-0,92 µM), kalsitriol (250 nM) ve kalsitriol olmaksızın MCF-7 hücre hattı ile sitotoksik etki saptaması için muamele edilmiştir. 0,46 µM doksorubisin ve optimum kalsitriol kombinasyonunun sitotoksik açıdan diğer dozlara göre anlamlı olduğu (p=0,0087) fakat doksorubisin kullanımında doz azaltımını sağlayacak kadar etkin olmadığı saptanmıştır. Sonuç: Doksorubisinin, kalsitriol ile kombine kullanımının günümüzde kullanılan dozlar üzerinde azaltıcı yönde anlamlı bir etkisinin olmadığını saptanmıştır. Vitamin D ve doksorubisin birlikte kullanımının meme kanserinde fayda sağlamayacağını söylemek için ise henüz erkendir. İlerleyen çalışmalarda vitamin D’nin farklı analogları ile çeşitli çalışmalar yapılabilir.
Palladium(II) and platinum(II) saccharinate complexes with bis(diphenylphosphino)methane/ethane: synthesis, S-phase arrest and ROS-mediated apoptosis in human colon cancer cells
(Royal Soc Chemistry, 2018) İçsel, Ceyda; Yılmaz, Veysel T.; Aygün, Muhittin; Cevatemre, Buse; Alper, Pınar; Ulukaya, Engin
New neutral [M(sac)(2)(diphos)] and cationic [M(diphos)(2)](sac)(2) complexes, where M = Pd-II or Pt-II, sac = saccharinate, and diphos = 1,1-bis(diphenylphosphino)methane (dppm) or 1,2-bis(diphenylphosphino)ethane (dppe), were synthesized and structurally characterized. The anticancer activity of the complexes was investigated against MCF-7 (breast), A549 (lung), HCT116 (colon), DU145 (prostate) cancer and BEAS-2B (normal bronchial epithelial) cells. Neutral Pt-dppm (2) and Pd-dppe complexes (5) did not show any biological activity. The cationic Pd-dppe (7) complex displayed antiproliferative activity, while the rest of the complexes exhibited potent cytotoxicity compared with cisplatin. The active Pd(ii)/Pt(ii) complexes were then included in further studies including interaction with DNA/HSA, nuclease activity, cellular uptake and lipophilicity. The potent complexes induced the apoptotic cell death as probed through annexin V positivity and caspase activation. Mechanistic studies on HCT116 cells showed that the complexes cause cell cycle arrest at the DNA synthesis (S) phase and excessive generation of reactive oxygen species (ROS), damaging to both mitochondria and DNA.
A palladium(II)-saccharinate complex of terpyridine exerts higher anticancer potency and less toxicity than cisplatin in a mouse allograft model
(Lippincott Williams & Wilkins, 2017) Çetin, Yüksel; Adıgüzel, Zelal; Polat, Hivda U.; Akkoç, Tolga; Taş, Arzu; Cevatemre, Buse; Çelik, Gokalp; Çarıkçı, Barış; Yılmaz, Veysel T.; Ulukaya, Engin; Açılan, Ceyda
The main aim of this study is to assess the safety and antitumor efficacy of a palladium(II) (Pd)-saccharinate complex with terpyridine. To characterize the Pd(II) complex in vitro, its cytotoxicity was evaluated using a water-soluble tetrazolium salt cell viability assay and the mechanism of cell death was assessed by DNA fragmentation/condensation and live cell imaging analyses. The antitumor efficacy and safety of the Pd(II) complex in-vivo were examined by analyzing reduction in tumor size, changes in body and organ weight, histopathological analysis of liver, kidney, and tumor sections, and biochemical analysis of serum in C57BL/6 mice. Our results showed that the Pd(II) complex was more cytotoxic to cancer cells than noncancer cell lines and caused cell death through apoptotic pathways. The treatment of the Pd(II) complex in tumor-bearing mice effectively reduced the tumor size at half the dose used for cisplatin. The Pd(II) complex appeared to exert less liver damage than the cisplatin-based complex on changes in the hepatic enzymes levels in the serum. Hence, the complex appears to be a potential chemotherapeutic drug with high antitumor efficacy and fewer hepatotoxic complications, providing an avenue for further studies. Anti-Cancer Drugs 28: 898-910 Copyright (C) 2017 Wolters Kluwer Health, Inc. All rights reserved.
A promising natural product, pristimerin, results in cytotoxicity against breast cancer stem cells in vitro and xenografts in vivo through apoptosis and an incomplete autopaghy in breast cancer
(Academic Press Ltd- Elsevier Science Ltd, 2018) Cevatemre, Buse; Erkısa Genel, Merve; Aztopal, Nazlıhan; Karakaş Zeybek, Didem; Alper, Pınar; Tsimplouli, Chrisiida; Sereti, Evangelia; Dimas, Konstantinos; Armutak, Elif I. İkitimur; Gürevin, Ebru Gürel; Üvez, Ayça; Mori, Mattia; Berardozzi, Simone; Ingallina, Cinzia; D'Acquarica, Ilaria; Botta, Bruno; Özpolat, Bülent; Ulukaya, Engin
Several natural products have been suggested as effective agents for the treatment of cancer. Given the important role of CSCs (Cancer Stem Cells) in cancer, which is a trendy hypothesis, it is worth investigating the effects of pristimerin on CSCs as well as on the other malignant cells (MCF-7 and MDA-MB-231) of breast cancer. The anti-growth activity of pristimerin against MCF-7 and MCF-7s (cancer stem cell enriched population) cells was investigated by real time viability monitorization (xCELLigence System (R)) and ATP assay, respectively. Mode of cell death was evaluated using electron and fluorescence microscopies, western blotting (autophagy, apoptosis and ER-stress related markers) and flow cytometry (annexin-V staining, caspase 3/7 activity, BCL-2 and PI3K expressions). Pristimerin showed an anti-growth effect on cancer cells and cancer stem cells with IC50 values ranging at 0.38-1.75 mu M. It inhibited sphere formation at relatively lower doses (<1.56 mu M). Apoptosis was induced in MCF-7 and MCF-7s cells. In addition, extensive cytoplasmic vacuolation was observed, implying an incompleted autophagy as evidenced by the increase of autophagy-related proteins (p62 and LC3-II) with an unfolded protein response (UPR). Pristimerin inhibited the growth of MCF-7 and MDA-MB-231-originated xenografts in NOD.CB17-Prkdc(scid)/J mice. In mice, apoptosis was further confirmed by cleavage of PARP, activation of caspase 3 and/or 7 and TUNEL staining. Taken together, pristimerin shows cytotoxic activity on breast cancer both in vitro and in vivo. It seems to represent a robust promising agent for the treatment of breast cancer. Pristimerin's itself or synthetic novel derivatives should be taken into consideration for novel potent anticancer agent(s). (C) 2017 Elsevier Ltd. All rights reserved.
A promising therapeutic combination for metastatic prostate cancer: Chloroquine as autophagy inhibitor and palladium(II) barbiturate complex
(Elsevier B.V., 2020) Erkısa Genel, Merve; Aydınlık, Şeyma; Cevatemre, Buse; Aztopal, Nazlıhan; Akar, Remzi Okan; Çelikler, Serap; Yılmaz, Veysel Turan; Ari, Ferda; Ulukaya, Engin
Autophagy is a catabolic process for cells that can provide energy sources and allows cancer cells to evade cell death. Therefore, studies on the combination of autophagy inhibitors with drugs are increasing as a new treatment modality in cancer. Previously, we reported the anti-tumor activity of a Palladium (Pd)(II) complex against different types of cancer in vitro and in vivo. Chloroquine (CQ), the worldwide used anti-malarial drug, has recently been focused as a chemosensitizer in cancer treatment. The aim of this study was to investigate the efficacy of a combined treatment of these agents that work through different mechanisms to provide an effective treatment modality for metastatic prostate cancer that is certainly fatal. Metastatic prostate cancer cell lines (PC-3 and LNCaP) were treated with Pd (II) complex, CQ, and their combination. The combination enhanced apoptosis by increasing phosphatidylserine translocation and pro-apoptotic proteins. Apoptosis was confirmed by the use of apoptosis inhibitor. The formation of acidic vesicular organelles (AVOs) was observed by acridine orange staining in fluorescence microscopy. The Pd (II) complex increased AVOs formation in prostate cancer cells and CQ-pretreatment has potentiated this effect. Importantly, treatment with CQ suppressed the pro-survival function of autophagy, which might have contributed to enhanced cytotoxicity. In addition, PI3K/AKT/mTOR-related protein expressions were altered after the combination of treatments. Our results suggest that combination treatment enhances apoptotic cell death possibly via the inhibition of autophagy, and may therefore be regarded as a novel and better approach for the treatment of metastatic prostate cancer. © 2020 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM)
Structures and anticancer activity of chlorido platinum(II) saccharinate complexes with mono- and dialkylphenylphosphines
(Elsevier Science Inc, 2019) İçsel, Ceyda; Yılmaz, Veysel T.; Cevatemre, Buse; Aygün, Muhittin; Ulukaya, Engin
cis-[PtCl(sac)(PPh2Me)(2)] (1), cis-[PtCl(sac)(PPhMe2)(2)] (2), trans-[PtCl(sac)(PPh2Et)(2)] (3) and trans- [PtCl(sac) (PPhEt2)(2)] (4) complexes (sac = saccharinate) were synthesized and characterized by elemental analysis and spectroscopic methods. The structures of 2-4 were determined by X-ray single-crystal diffraction. The interaction of the complexes with DNA was studied various biochemical, biophysical and molecular docking methods. Only the cis-configured complexes (1 and 2) showed nuclease activity and their binding affinity towards DNA was considerably higher than those of their trans-congeners (3 and 4). The chlorido ligand in the cis-configured complexes underwent aquation, making them more reactive towards DNA. Furthermore, 1 and 2 exhibited anticancer potency on breast (MCF-7) and colon (HCT116) cancer cells similar to cisplatin, whereas 3 and 4 were biologicallly inactive. Mechanistic studies on MCF-7 cells showed that higher nuclear uptake, cell cycle arrest at the S phase, dramatically increased DNA double-strand breaks, apoptosis induction, elevated levels of reactive oxygen species (ROS) and high mitochondrial membrane depolarization greatly contribute to the anticancer potency of 1 and 2.
A trans-platinum(II) complex induces apoptosis in cancer stem cells of breast cancer
(Pergamon-Elsevier Science Ltd, 2017) Aztopal, Nazlıhan; Karakaş, Didem; Cevatemre, Buse; Arı, Ferda; İçsel, Ceyda; Daidone, Maria G.; Ulukaya, Engin
Recent accumulating evidence has supported the notion that tumors have hierarchically organized heterogeneous cell populations and a small subpopulation of cells, termed cancer stem cells (CSCs), are responsible for tumor initiation, maintenance as well as drug resistance. Therefore, targeting the CSCs along with the other cancer cells has been the most important topic during the last decade. In the present study, we evaluated the cytotoxic activity of trans-[PtCl2(2-hepy) 2] [2-hepy = 2-(2-hydroxyethyl) pyridine] complex and the mechanism of cell death in breast CSCs. Stemness markers, Oct-4 and Sox2, were determined in mammospheres by western blotting. Cytotoxicity was assessed using the ATP viability assay. Cell death was fluorescently visualized and further confirmed by flow cytometry as well as gene expression analysis. The Pt(II) complex significantly reduced the cell viability, prevented mammosphere formation and disrupted mammosphere structures in a dose-dependent manner (0100 lM). The mode of cell death was apoptosis and it was shown by the presence of caspase 3/7 activity, Annexin V-FITC positivity, decreased mitochondrial membrane potential and increased expressions of pro-apoptotic genes (TNFRSF10A and HRK). Interestingly, necroptosis was also observed by the evidence of increased MLKL expression. In conclusion, the Pt(II) complex seems to be a highly promising anticancer compound due to its promising cytotoxic activity on CSCs. Therefore, it deserves in vivo further studies for the proof-of-concept. (C) 2016 Elsevier Ltd. All rights reserved.
Unfolded Protein Response is Involved in Trans-Platinum (II) Complex-Induced Apoptosis in Prostate Cancer Cells via ROS Accumulation
(Bentham Science Publ Ltd, 2019) Karakaş Zeybek, Didem; Cevatemre, Buse; Oral, Arzu Y.; Yılmaz, Veysel T.; Ulukaya, Engin
Background: Prostate cancer is one of the most common cancer types and it is the sixth leading cause of cancer-related death in men worldwide. Even though novel treatment modalities have been developed, it still a lifethreatening disease. Therefore novel compounds are needed to improve the overall survival. Methods: In our study, it was aimed to evaluate the anti-cancer activity of newly synthesized Platinum (II) [Pt(II)] complex on DU145, LNCaP and PC-3 prostate cancer cell lines. The cytotoxic activity of Pt(II) complex was tested by SRB and ATP cell viability assays. To detect the mode of cell death; fluorescent staining, flow cytometry and western blot analyses were performed. Results: The Pt(II) complex treatment resulted in a decrease in cell viability and increasing levels of apoptotic markers (pyknotic nuclei, annexin-V, caspase 3/7 activity) and a decrease in mitochondrial membrane potential in a dose dependent manner. Among cell types, tested PC-3 cells were found to be more sensitive to Pt(II) complex, demonstrating elevation of DNA damage in this cell line. In addition, Pt(II) complex induced Endoplasmic Reticulum (ER) stress by triggering ROS generation. More importantly, pre-treatment with NAC alleviated Pt(II) complex-mediated ER stress and cell death in PC-3. Conclusion: These findings suggest an upstream role of ROS production in Pt(II) complex-induced ER stressmediated apoptotic cell death. Considering the ROS-mediated apoptosis inducing the effect of Pt(II) complex, it warrants further evaluation as a novel metal-containing anticancer drug candidate.

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