Browsing by Author "Yurtcu, Erkan"

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Benzamide and Benzamidine Compounds as New Inhibitors of Urokinase-type Plasminogen Activators
(2018) Kus, Canan; Ozer, Ezgi; Korkmaz, Yesim; Yurtcu, Erkan; Dagalp, Rukiye; 0000-0001-6141-6788; 0000-0003-4930-8164; 0000-0002-7335-8578; 30112993; AAG-1459-2020; AAA-2998-2021; W-1812-2017
Background & Method: In this ongoing research, it is aimed to investigate the synthesis, structure identification and effects on urokinase-type plasminogen activators (uPA) and its receptor levels of 4-(3H-imidazo[4,5-b] pyridin-2-yl)-N-substituted benzamide and benzamidine derivatives. uPA levels obtained from 4b and 7d administration were similar to 5-FU (5-fluorouracil) for colorectal carcinoma cells (p<0.05). 4b and 7d significantly reduced uPAR (urokinase-type plasminogen activator receptor) levels on both cell lines (p<0.05). Conclusion: uPAR levels obtaining from 4b and 7d administration were similar to 5-FU for both cell lines colorectal (Colo205, CCL-222) and hepatocellular (HepG2, CCL-23) carcinoma cells (p<0.05).
beta-Adrenoreceptor antagonists reduce cancer cell proliferation, invasion, and migration
(2014) Iseri, Ozlem Darcansoy; Sahin, Feride Iffet; Terzi, Yunus Kasim; Yurtcu, Erkan; Erdem, S. Remzi; Sarialioglu, Faik; 25026350
Context: Propranolol, atenolol, and ICI118,551 are non-selective beta-adrenergic receptor (AR), beta(1)-AR, and beta(2)-AR antagonists, respectively. Objective: We investigated the efficacy of propranolol, atenolol, and ICI118,551 on proliferation, migration, and invasion of non-stimulated breast (MCF7), colon (HT-29), and hepatocellular (HepG2) cancer cells. Materials and methods: beta-AR expression profiling of cells was performed by real time PCR. Cell proliferation was determined by MTT. Boyden chamber and scratch assays were performed to evaluate invasion and migration. Results and discussion: All cell lines expressed beta-ARs. ICI118,551 was the most cytotoxic, whereas atenolol was the least effective beta-AR antagonist for 24, 48, and 72 h. Cell invasion was inhibited by ICI118,551 (45, 46, and 50% for MCF7, HT29, and HepG2, respectively) and propranolol (72, 65, and 90% for MCF7, HT29, and HepG2, respectively). Propranolol, atenolol, and ICI118,551 reduced migration of MCF7, HT-29, and HepG2 cells to varying extents depending on the application concentration and duration. Propranolol and atenolol reduced migration of MCF7 and HT-29 in a concentration-dependent manner, whereas migration of these cells decreased after 48 and 72 h of ICI118,551 applications. Conclusion: Beta(2)-AR antagonist seemed to be the most cytotoxic beta-blocker on non-stimulated cancer cells. Propranolol and ICI118,551 were more effective than atenolol in inhibiting invasion and migration of non-stimulated MCF7 and HT-29 cells; ICI118,551 being the most potent. Concordantly, beta(2)-selective blockage seemed to be more effective for non-stimulated cells. Effect of the selective beta-AR antagonists showed variation depending on the concentration, incubation time, and histological origin of cells.
Çeşitli hücre hatlarında silimarinin epigenetik etkisinin değerlendirilmesi
(Başkent Üniversitesi Sağlık Bilimleri Enstitüsü, 2019) Korkmaz Kasap, Yeşim; Yurtcu, Erkan
Epigenetik değişimler kanser gelişiminde etkilidirler. Waddington 1940'lı yıllarda epigenetiği DNA'nın baz dizilimini değiştirmeden gen ifadelenmesinin değişmesi olarak açıklamıştır. DNA metilasyonu, histon modifikasyonları, kromatin yeniden modelleme ve kodlamayan RNA’lar (mikro-RNA, uzun kodlamayan RNA’lar ve PIWI proteiniyle ilişkili RNA’lar) temel epigenetik mekanizmalar olarak kabul edilmektedir. Kanser hücrelerinde tümör gelişimi ile ilgili yolakları etkilediği için epigenetik değişiklikler, tümörün oluşumunda ve ilerlemesinde önemli rol oynamaktadır. Epigenetik etkili ilaçlar hücre döngü kontrolü, apoptozis, hücre sinyalizasyonu, invazyon, metastaz ve anjiyogenez ile ilgili gen ifadelerinin kontrolünde kullanılmaktadır. Epigenetik düzensizliklerin geri döndürülebilir olması, DNA metilasyon ve histon asetilasyon inhibitörlerinin kanser tedavisinde kullanımına olanak sağlamaktadır ve DNA modifikasyonu ve histon modifikasyonu gibi epigenetik farklılıkların hedef alınarak kanser tedavisinde etkili bir strateji izlenebileceği gösterilmiştir. DNA metilasyon ve histon modifikasyon profilini değiştirebilen ilaç adayı bileşikler geliştirilmeye başlanarak preklinik ve klinik aşamalara geçilmiştir. 5-azasitidin ve SAHA inhibitör grupları Food and Drug Administration (FDA) tarafından onaylanan tek başlarına veya kemoterapi, radyoterapi gibi sitotoksik ajanlarla birlikte uygulanmaktadır. 5-azasitidin, yapısal olarak sitozin nükleotidine benzemektedir ve DNA metiltransferazların inhibisyonunu sağlamaktadır. Epigenetik mekanizmalar kullanılarak geliştirilen bir diğer tedavi ajanı histon deasetilaz (HDAC) inhibitörü olan SAHA’dır. Silimarin, Asteraceae familyasına ait devedikeni olarak da adlandırılan Silybum marianum L. bitkisinin tohumlarından elde edilmektedir. Silimarin kimyasal olarak bir polifenol olup, bitki kimyası olarak da bir flavonolignandır. Yapılan çalışmalarla silimarinin antioksidan, antimetastatik, antianjiyogenik ve antiinflamatuar etkileri gösterilmiştir. Silimarin, antikarsinojenik etkileri sebebiyle kemoterapi alan hastalar arasında tamamlayıcı ve alternatif tedavi amacıyla en sık kullanılan ajandır. Bu çalışma ile silimarinin çeşitli kanser hücre dizilerinde epigenetik regülasyon üzerine olan etkisinin değerlendirilmesi amaçlanmıştır. İnsan nöroblastom hücre dizisi SHSY5Y hücreleri, insan hepatosellüler hücre dizisi HepG2 hücreleri veinsan meme kanseri hücre dizisi MCF-7 hücreleri %5 CO2 ve %95 nem içeren 37°C'lik inkübatörde çoğaltıldı. Silimarin, 5-azasitidin ve SAHA'nın genotoksik dozları MTT testi ile belirlendi. Belirlenen IC50 dozlarına göre hücrelere 48 saatlik uygulama yapıldı. DNMT ve HDAC enzim aktiviteleri ölçüldü. Western Blot ile p53, cMyc ve NFκB protein düzeyleri belirlendi. Silimarinin epigenetik yolaklara olan etkisi ile ilgili sınırlı sayıda çalışma bulunmaktadır. Bu çalışmada ile silimarinin tek başına ve epigenetik inhibitörler ile birlikte uygulandığında çeşitli kanser hücre dizilerinde epigenetik enzimler ve protein düzeylerine olan etkileri değerlendirilmiştir. Sonuçlarımıza göre silimarin DNMT üzerinde inhibe edici etki göstermiştir. HDAC üzerinde inhibisyon etki görülmemiştir. Silimarin p53 K373, p53 K382, cMyc ve NFκB protein seviyelerini baskılarken, p53 S46 protein seviyesini artırmıştır. Bu çalışma Başkent Üniversitesi Tıp ve Sağlık Bilimleri Araştırma Kurulu (Proje no: DA 17/09) tarafından onaylanmış ve Başkent Üniversitesi Araştırma Fonu tarafından desteklenmiştir. Epigenetic changes are effective in cancer development. Waddington described epigenetics in the 1940s as a change in gene expression without altering the base sequence of DNA. DNA methylation, histone modifications, chromatin remodeling and non-coding RNAs (micro-RNAs, long non-coding RNAs, and PIWI proteinrelated RNAs) are accepted for basic epigenetic mechanisms. Epigenetic changes play important roles in tumor formation and progression since it affects pathways related to tumor development in cancer cells. Epigenetically effective drugs are used in the control of gene expression related to cell cycle control, apoptosis, cell signaling, invasion, metastasis and angiogenesis. Reversibility of epigenetic irregularities allows the use of DNA methylation and histone acetylation inhibitors in the treatment of cancer, and has been shown to be an effective strategy in cancer treatment by targeting epigenetic differences such as DNA modification and histone modification. Drug candidate compounds capable of altering DNA methylation and histone modification profile have begun to develop and have been switched to preclinical and clinical stages. 5-azacitidine and SAHA inhibitor groups are administered alone or in combination with cytotoxic agents such as chemotherapy, radiotherapy approved by the Food and Drug Administration (FDA). 5-azacytidine is structurally similar to the cytosine nucleotide and provides for inhibition of DNA methyltransferases. Another therapeutic agent developed using epigenetic mechanisms is the histone deacetylase (HDAC) inhibitor SAHA. Silymarin is obtained from the seeds of Silybum marianum L. also called milk thistle of Asteraceae family. The most important active ingredient is silymarin is a polyphenol chemically and a flavonolignant as plant chemistry. Antioxidant, antimetastatic, antiangiogenic and antiinflammatory effects of silymarin have been shown in the studies. Silymarin is the most frequently used agent for complementary and alternative therapy among chemotherapy patients due to its anticarcinogenic effects. The aim of this study was to evaluate the effect of silymarin on epigenetic regulation in various cancer cell lines. Human neuroblastoma cell line SHSY5Y cells, human hepatocellular cell line HepG2 cells and human breast cancer cell line MCF-7 cells were grown in a 37°C incubator containing 5%CO2 and 95% humidity. Genotoxic doses of silymarin, 5- azacytidine and SAHA were determined by MTT test. Cells were treated for 48 hours according to the determined IC50 doses. DNMT and HDAC enzyme activities were measured. p53, cMyc and NFκB protein levels were determined by Western Blot. There are a limited number of studies on the effect of silymarin on epigenetic pathways. In this study, the effects of silymarin on epigenetic enzymes and protein levels in various cancer cell lines when used alone and in combination with epigenetic inhibitors were evaluated. According to our results, silymarin showed an inhibitory effect on DNMT. There was no inhibition effect on HDAC. Silymarin inhibited p53 K373, p53 K382, cMyc and NFκB protein levels, while increased p53 S46 protein level. This study was approved by Baskent University Medical and Health Sciences Research Council (Project no: DA 17/09) and supported by Baskent University Research Fund.
Could radial extracorporeal shock wave therapy have an effect on wound healing in clinical practice by creating genotoxic damage? An in-vitro study in mouse fibroblasts
(2021) Simsek, Ekin Kaya; Haberal, Bahtiyar; Kasap, Yesim Korkmaz; Yurtcu, Erkan; 0000-0003-3438-1633; 0000-0002-1668-6997; 34842098; AAV-8821-2021; W-9080-2019
Objectives: This study aims to evaluate wound healing effects of in vitro radial extracorporeal shock wave (rESW) application on mouse fibroblasts and whether the cytotoxic effect of extracorporeal shock wave (ESW) was due to a possible genotoxic effect. Patients and methods: After creating an in vitro wound healing model in L929 mouse fibroblast culture, fibroblasts were stimulated with a frequency of 3 Hz, and 100, 250, 500, 1,000 and 1,500 pulses shock waves were applied. Energy flux densities ranging from 0.01 to 0.23 mJ/mm2 (14.3 MPa) at a constant pressure level of 0.5 and 1 bar were applied. Wound healing, cell viability, and genotoxicity were evaluated at 24 and 48 h. Results: All shot numbers for both pressures significantly reduced cell viability (p<0.05). For both 0.5 and 1 bar pressures, in both intervals, the rate of wound healing decreased, regardless of the number of shots (p<0.05). In vitro genotoxic damage was detected at both 0.5 and 1 bar pressures, in both time intervals, regardless of the number of shots. The genotoxic damage increased from 24 h to 48 h. Conclusion: The study results suggest that, when ESWT is applied in this in vitro experimental setup, cell viability decreases and wound healing is delayed under all conditions. Furthermore, genotoxic damage can be prevented by using shots below 1,000 pulses. Therefore, while investigating the therapeutic effect of ESW therapy in vitro, the upper limit for the number of shots should be 1,000 pulses.
Does Theobromine Increase the Apoptotic Effect of STI571?
(2016) Kasap, Yesim Korkmaz; Ozdemir, Zeynep; Asparuk, Cagan; Ak, Oguzhan; Aysun, Dide; Akgor, Doga; Elmastas, Fulya; Akkus, Dogukan; Yurtcu, Erkan; 0000-0003-4930-8164; AAA-2998-2021
Objective: STI571, a selective tyrosine kinase inhibitor is used in CML chemotherapy. It has limited effects in some cases due to drug resistance and intoxication as other chemotherapeutic agents. Thus, many cancer patients use dietary supplements and herbal extracts for increasing the effectiveness of chemotherapeutic agents. Theobromine, a metabolite of cacao has prooxidant effects and regulates intercellular signaling pathways. The aim of the study is to determine the potential apoptotic effects of STI571 and theobromine on K562 cells, when used alone and in combination. Methods: Inhibitory concentrations of STI571 and theobromine were determined by MTT method. Both agents were applied to the cells at 48 h time period alone and in combination. Caspase activities were assessed colorimetrically. Apoptosis and necrosis were evaluated by using acridine orange/ethidium bromide staining. p<0.05 was considered as statistically significant. Results: Caspase activities increased when both agents administrated alone. Theobromine increased effects of STI571 on caspase activities in time and type dependent manner (p<0.05). Apoptotic cell rates also increased when two agents applied in combination (p<0.05) in time dependent manner. Theobromine also reduced necrotic cell rates. Conclusion: Although there are limited data about the intracellular effects of theobromine, we showed that theobromine has effects on the caspase pathway related apoptotic response carried out by STI571. We believe that this in vitro study will shed light for further researches.
Effect of Melatonin on Cytokine Levels in A Hyperthermia-Induced Febrile Seizure Model
(2017) Aydin, Leyla; Yurtcu, Erkan; Korkmaz, Yesim; Sezer, Taner; Ogus, Ersin; 0000-0003-4930-8164; 0000-0002-2278-1827; 0000-0002-9877-421X; 29208169; ABC-5392-2020; AAA-2998-2021; AAJ-5931-2021; AAJ-1058-2021
Higher serum cytokine levels have been reported in children admitted with febrile seizures and in some experimental models. However, other studies have shown that cytokine levels are influenced by melatonin. In this study, we investigated serum cytokine levels in a hyperthermia-induced febrile rat seizure model and the effect of melatonin. A total of 28 male Sprague-Dawley rats were divided into four groups: the control (C) group, healthy melatonin (MT) group, and hyperthermia-induced febrile seizure groups with (HIFS-MT) and without (HIFS) administration of melatonin. Melatonin (80 mg/kg) was given intraperitoneally 15 min before the seizure. HIFS was induced by placing the rats in 45 degrees C water. The rats were sacrificed under anesthesia after the seizure. Blood samples were drawn by transcardiac puncture to measure serum cytokine and melatonin levels. Serum interleukin (IL)-1 beta, IL-6, IL-10, and tumor necrosis factor (TNF)-alpha levels were lower in the HIFS group than those in the C group (p = 0.005, p = 0.200, p = 0.011, and p = 0.016, respectively). All serum cytokine levels of rats in the MT and HIFS-MT groups were similar to those in the C group. This experimental rat model demonstrated that serum cytokine levels decrease with HIFS and that administering melatonin maintains serum cytokine levels. These results suggest that cytokines may play role in the anticonvulsive activity of melatonin in rats with febrile seizures.
Effect of mometasone furoate nasal spray on the DNA of nasal mucosal cells
(2018) Aydin, Erdinc; Akkas, Hakan; Turkoglu Babakurban, Seda; Yurtcu, Erkan; Yilmaz Ozbek, Ozlem; 0000-0001-5067-4044; 0000-0001-6864-7378; 0000-0003-4930-8164; 29714449; AAI-8856-2021; AAJ-2379-2021; AAA-2998-2021
Background/aim: Allergic rhinitis (AR) is a respiratory disease caused by inflammation of the nasal mucosa. Intranasal corticosteroids (ICs) are an effective treatment for AR; however, their use has been associated with atrophy in nasal mucosae. Because DNA damage has been linked to several chronic diseases, we hypothesize that use of ICs could cause DNA damage in nasal mucosa cells, leading to mucosal atrophy and septal perforation. Materials and methods: Sixty patients with moderate or severe AR were divided randomly into two groups. Mometasone furoate (MF) and antihistamine tablets (desloratadine) were given to the study (IC) group. Physiologic saline and desloratadine were given to the control ((serum physiologic (SP)) group. Nasal irrigation fluid was taken from patients before study commencement and after 4 weeks of treatment. The comet assay was applied to detect DNA damage in nasal mucosa cells. Results: Nineteen patients were excluded, leaving a study population of 41 patients (IC group: 17 patients; SP group: 24 patients). Genotoxic damage was evaluated by comet assay. Conclusion: Treatment with MF spray for 4 weeks does not cause DNA breaks within cells in the nasal mucosa. These results could form the basis of clinical trials involving treatment with different ICs over longer treatment periods.
Effects of Silymarin and Silymarin-Doxorubicin Applications on Telomerase Activity of Human Hepatocellular Carcinoma Cell Line HepG2
(2015) Yurtcu, Erkan; Iseri, Ozlem Darcansoy; Sahin, Feride Iffet; 0000-0001-7308-9673; 0000-0003-4930-8164; 26011349; AAC-7232-2020; AAA-2998-2021
Purpose: Hepatocellular carcinoma (HCC) is resistant to conventional chemotherapeutics such as doxorubicin. Milk thistle extract, or its active constituent silymarin has been used by cancer patients as an alternative and complementary agent. Telomerase activation is one of the initial events of HCC. In this study, we applied doxorubicin and silymarin for 72 hrs in order to test individual and combined effect of the agents on telomerase activity. Methods: The effects of doxorubicin, silymarin, and their combination on the proliferation of HepG2 cell line were tested by MTT assay, and Checkerboard micro plate method was applied to define the nature of doxorubicin and silymarin interactions on the cells. Lipid peroxidations were assessed by thiobarbituric acid reactive substance (TBARS) level. Telomerase activity was determined according to the telomeric repeat amplification protocol (TRAP). Untreated cells were used as control group. Results: Doxorubicin-silymarin combination had indifferent antiproliferative effects on HepG2 cells. Telomerase activity of the cells incubated with IC50 of doxorubicin and silymarin decreased to 72% (p<0.05). IC50 combinations of doxorubicin and silymarin caused 70% (p<0.05) reduction. All treatments except for the 1/2IC(50) of silymarin caused significant increase in lipid peroxidation levels when compared to controls. TBARS levels did not significantly increase when doxorubicin and silymarin were applied in combination, which is in concordance with the indifferent drug interaction. Conclusion: IC50 of both doxorubicin and silymarin alone and in combination inhibited telomerase activity. Mechanism of inhibition may be elucidated by further molecular studies.
Fractalkine receptor polymorphism may not be associated with the development and clinical course of ulcerative colitis
(2015) Gokcan, Hale; Yurtcu, Erkan; Selcuk, Haldun; Sahin, Feride I.; 26042517
Fractalkine (CX3C), a chemokine expressed by epithelial cells within normal and inflamed colorectal mucosa, induces leukocyte adhesion and migration via fractalkine receptor. The aim of this study was to investigate two single nucleotide polymorphisms of the fractalkine receptor gene as a risk factor both for the development and clinical findings of ulcerative colitis. In this study, si patients with ulcerative colitis (UC) and 8o controls were recruited. Genotypes of fractalkine receptorc.743G>A (V249I) and c.839C>T (T280M) polymorphisms were identified by restriction fragment length polymorphism analyses after polymerase chain reaction.Genotype distribution and allele frequencies of V249I and T280M were not statistically significantly different between UC and control groups (p>0.05). No statistically significant relationship was found between fractalkine receptor polymorphisms and clinical findings of UC. We observed no significant difference in fractalldne receptor polymorphism between patients and control group and no genotype-phenotype relation. Therefore, we concluded that fractalkine receptor polymorphisms may not contribute to the molecular pathogenesis of UC.
Genisten kronik myeloblastik hücre dizisinde sinyal yolaklarına etkisinin değerlendirilmesi
(Başkent Üniversitesi Sağlık Bilimleri Enstitüsü, 2016) Erden Armutçuoğlu, Nur; Yurtcu, Erkan
Kronik myeloid lösemi (KML) malign klonal hematopoetik kök hücre hastalığıdır. Moleküler patogenezinde Philadelphia (Ph) kromozomu üzerindeki BCR-ABL1 füzyon geni rol oynar. Oluşan füzyon proteini tirozin kinaz kodlar ve bu tirozin kinaz AKT, ERK, STAT yolakları üzerinde etkili olup modülatörleri GAB2 ve GRB2’dir. KML tedavi protokolünde yer alan STI571 (imatinib mesilat, Gleevec™), tirozin kinaz özelliği olan bu enzimin ATP-bağlayıcı bölgesine yarışmalı inhibisyonla bağlanır. Genistein; östrojenik özeliğinin yanı sıra tirozin kinaz inhibitör aktivitesine sahip olan bitkisel bir flavonoiddir. Bu çalışmada, insan KML hücre dizisi K562 hücrelerine STI571 uygulaması ile birlikte genistein uygulamasının hücre içi sinyal yolakları üzerine etkisinin protein seviyesinde belirlenmesi hedeflenmiştir. K562 hücre dizisi %5’lik CO2, %95 nem içeren 37oC’lik inkübatörde çoğaltıldı. STI571 ve genisteinin sitotoksik dozu MTT testi ile belirlendi. STI571 ve genisteinin etkileri 24 ve 48 saat periyotlarla değerlendirildi. Hücrelere STI571, genistein, STI571 ve genistein kombinasyonları birlikte uygulandı. Kontrol grubu olarak kullanılan hücre grubuna bir uygulama yapılmadı. Tüm gruplarda protein düzeyleri ELISA metoduyla belirlendi. Sonuçlar uygun istatiksel yöntemlerle değerlendirildi. Verilerimiz toplu halde değerlendirildiğinde STI571 ve genisteinin tek başına ya da birlikte uygulanması ile protein düzeylerinde anlamlı bir değişikliğe neden olmadığı belirlendi. Bu çalışmada ilk kez genisteinin STI571 ile birlikte etkileri bir protein paneli üzerinde değerlendirilmiştir. STI571’in ve genisteinin tirozin kinaz inhibitörü özellikleri bilinmektedir. Ancak her iki ajanın protein düzeyleri üzerine etkilerini inceleyen çalışmalarda tartışmalı sonuçlar mevcuttur. Biz de STI571 ve genisteinin tek başına ve birlikte kullanımıyla bu tartışmalı konuya açıklık getirmeyi hedefledik. Sonuçlarımıza göre her iki ajanın birlikte kullanılmasının protein düzeyleri açısından anlamlı bir fark oluşturmadığını gösterdik. Chronic myeloid leukemia (CML) is a malign clonal hematopoietic stem cell disease. BCR-ABL1 is a fusion gene which is located on Philadelphia (Ph) chromosome, plays a role on molecular pathogenesis of the disease. Induced fusion protein encodes the tyrosine kinase which has effect on AKT, ERK, STAT pathways and GAB2 and GRB2 are its modulators. STI571 (imatinib mesilat) which is used for CML treatment protocol, has tyrosine kinase inhibitor property and binds to the ATP-binding region of this enzyme with competitive inhibition. Genistein is a herbal flavonoid which has estrogenic effects besides tyrosine kinase inhibitor. In this study, we aimed to determine the effect of STI571 and genistein application for intercellular signal transduction pathways at protein level on the human CML cell line K562 cells. K562 cells were cultured at 5% CO2, 95% humidity and 37 oC. The cytotoxic dosages of STI571 and genistein were determined with MTT test. The effects of STI571 and genistein were evaluated at 24 and 48 hours period. The cells were treated to STI571, genistein alone and STI571 and genistein combination. Untreated cells were used as control group. The protein levels of all groups were determined by ELISA method. The data were evaluated statistically. There was no statistically significant alteration about the amount of protein levels with STI571 and genistein alone and in combination. This is the first report about the effects of STI571 and genistein on a protein panel. STI571 and genistein are well known agents about their tyrosine kinase inhibitory effects. However previous reports about these chemicals on the protein levels have controversial results. We aimed to contribute with our results about STI571and genistein when used alone or in combination. As a conclusion STI571and genistein have no statistically significant effect on the protein levels.
The Genotoxic Effect of Nasal Steroids on Human Nasal Septal Mucosa and Cartilage Cells In Vitro
(2023) Babakurban, Seda Turkoglu; Vural, Omer; Kasap, Yesim Korkmaz; Hizal, Evren; Yurtcu, Erkan; Buyuklu, Adnan Fuat; 0000-0001-5067-4044; 0000-0001-7157-0850; 35695134; AAI-8856-2021; AAJ-1454-2021
Objective: To determine whether budesonide (Bud) and triamcinolone acetate (TA) cause DNA fractures in the nasal mucosa and septal cartilage cells through examinations using the comet assay technique. Study design: Prospective, controlled experimental study. Setting: University hospital. Methods: Septal mucosal epithelial and cartilage tissue samples were taken from 9 patients. Cell cultures were prepared from these samples. Then, budesonide and triamcinolone acetate active ingredients at 2 different doses of 0.2 and 10 mu M were separately applied to the cell cultures formed from both tissues of each patient, except the control cell culture, for 7 days in one group and 14 days in one group. After the applications, genotoxic damage was scored with the comet assay technique and the groups were compared. Results: In both the budesonide and triamcinolone acetate groups, the comet scores at low and high doses, on the 7th and 14th days were found to be significantly higher in both cartilage and epithelial tissue than in the control group. Conclusion: The study results showed that budesonide and triamcinolone acetate lead to a significantly high rate of genotoxic damage in both epithelial tissue and cartilage tissue.
Improvement in antimicrobial properties of titanium by diethyl phosphite plasma-based surface modification
(2020) Kaleli-Can, Gizem; Ozguzar, Hatice Ferda; Kahriman, Selahattin; Turkal, Miranda; Gocmen, Julide Sedef; Yurtcu, Erkan; Mutlu, Mehmet
Titanium (Ti) has been commonly used as a biomaterial for dental applications. However, they have struggled with the formation of polymicrobial infections leading to peri-implantitis. In this research, antimicrobial activity of titanium modified via diethyl phosphite (DEP) plasma onto Staphylococcus aureus (S. aureus) and Candida albicans (C. albicans), the two most frequently encountered pathogens in peri-implantitis, were investigated. Surface modification with DEP was achieved with plasma polymerization technique in a low-pressure/radio-frequency plasma using 75 W of plasma power and 10 min of exposure time under 0.15 mbar. Hydrophilicity, surface energy and roughness of Ti surface was increased and anionic Ti surface became amphoteric after surface modification according to physical and chemical examinations. This process significantly enhanced the anti-microbial efficiency of Ti towards S. aureus and C. albicans cells compared to control groups via contact killing. Moreover, DEP coating shown excellent compatibility with 93 % of L929 fibroblast cell viability. These findings revealed that amphoteric plasma polymer prepared from DEP offers promising solution for preventing biofilm formation on Ti.
In Vitro Effects on Biofilm Viability and Antibacterial and Antiadherent Activities of Silymarin
(2015) Evren, Ebru; Yurtcu, Erkan; 0000-0003-4930-8164; 25937395; AAA-2998-2021; JWP-3001-2024
Limited treatment options in infectious diseases caused by resistant microorganisms created the need to search new approaches. Several herbal extracts are studied for their enormous therapeutic potential. Silymarin extract, from Silybum marianum (milk thistle), is an old and a new remedy for this goal. The purpose of this study is to evaluate the antibacterial and antiadherent effects of silymarin besides biofilm viability activity on standard bacterial strains. Minimal inhibitory concentration (MIC), minimal bactericidal concentration (MBC), antiadherent/antibiofilm activity, and effects on biofilm viability of silymarin were evaluated against standard bacterial strains. MIC values were observed between 60 and > 241 mu g/mL (0.25-> 1 mmol/L). Gram-positive bacteria were inhibited at concentrations between 60 and 120 mu g/mL. Gram-negative bacteria were not inhibited by the silymarin concentrations included in this study. MBC values for Gram-positive bacteria were greater than 241 mu g/mL. Adherence/biofilm formations were decreased to 15 mu g/mL silymarin concentration when compared with silymarin-untreated group. Silymarin reduced the biofilm viabilities to 13 and 46 % at 1 and 0.5 mmol/L concentrations, respectively. We demonstrated that silymarin shows antibacterial and antiadherent/antibiofilm activity against certain standard bacterial strains which may be beneficial when used as a dietary supplement or a drug.
İnsan kronik myeloblastik lösemi hücre dizisi k562'de imatinibin ve silimarinin BCR-ABL1, GRB2, GAB2, AKT ve ERK gen ifadelenmelerine olan etkisinin değerlendirilmesi
(Başkent Üniversitesi Sağlık Bilimleri Enstitüsü, 2014) Üntekin, Burcu; Yurtcu, Erkan
KML’nin moleküler patogenezinde Philadelphia (Ph) kromozomu üzerindeki BCRABL1 füzyon geni rol oynar. Oluşan füzyon protein AKT, ERK ve STAT yolaklarını aktive eden bir tirozin kinaz kodlarken bu proteinin modülatörleri GRB2 (Growth factor receptor-bound protein 2) ve GAB2 (Grb-2-associated binder 2)’dir. KML tedavi protokolünde yer alan STI571 (imatinib mesilat), tirozin kinaz özelliği olan bu enzimin ATP-bağlayıcı bölgesine kompetitif inhibisyonla bağlanır. BCR-ABL1 sinyal iletiminde görevli proteinlerin tirozin fosforilasyonu inhibe olur. Bu çalışmada, insan KML hücre dizisi K562 hücrelerinde STI571 uygulaması ile birlikte bitkisel bir flavonoid olan silimarin uygulamasının hücre içi sinyal yolakları üzerine etkisinin belirlenmesi hedeflenmiştir. K562 hücre dizisi RPMI besiyerinde %5’lik CO2, %95 nem içeren 37 0C’lik inkübatörde çoğaltıldı. STI571 sitotoksik dozu MTT testi ile belirlendikten sonra hücrelere STI571, silimarin, STI571 ve silimarin kombinasyonu birlikte uygulandı. Kontrol grubu olarak kullanılacak hücre grubuna hiçbir uygulama yapılmadı. Belirlenen doz ve uygulama süreleri sonunda tüm hücrelerden mRNA izolasyonu yapıldı ve bunu takiben cDNA elde edildi. BCRABL1, GRB2, GAB2, AKT ve ERK genlerinin ifadelenme düzeyleri real-time PCR yöntemi ile belirlendi. Sonuç olarak imatinib ve silimarin kombinasyonu uygulanan K562 hücrelerinde GAB2 ve ERK gen ifadelenme düzeylerinin azaldığı tespit edildi. Diyete ek olarak alınan silimarin aracılığıyla KML hücrelerinde imatinibin etkinliğinin artırılabileceğinin gösterilmesi ilaç dirençliliğinde rol oynayan sinyal moleküllerinin baskılanabileceğini akla getirmektedir. Bunun ileride yapılacak klinik çalışmalara ışık tutabileceğini düşünüyoruz. BCR-ABL1 fusion gene, located on Philedelphia (Ph) chromosome has a major role in the pathogenesis of CML. Fusion protein, the product of this translocation, encodes a tyrosine kinase that activates AKT, ERK and STAT pathways. The modulators of BCR-ABL1 fusion protein are GRB2 (Growth factor receptor-bound protein 2) and GAB2 (Grb-2-associated binder 2) in the activation of cell signalling pathways. STI571, that is given to patients in CML treatment protocol, binds to the ATP-binding domain of tyrosine kinase enyzme by competative inhibition. The tyrosine phosphorylation of the proteins, responsible of BCR-ABL1 signalling, is inhibited. The aim of this study is to determine the effect of silimarin, a herbal flavonoid, treatment together with STI571 on human CML cell line K562 signalling pathways. K562 cells were maintained in RPMI 1640 medium, at 37°C in a 95% (v/v) humidified atmosphere of 5% (v/v) CO2. After determining the cytotoxic dose of STI571 by MTT test, cells were treated by STI571, silymarin, and combination of both STI571 and silymarin. Control group was not treated with any of the substances. After the treatment of cells with previously designated doses and times, mRNA were isolated and cDNA were synthesed. BCR-ABL1, GRB2, GAB2, AKT and ERK gene expression levels were analyzed with real-time PCR. In conclusion, the decrease of GAB2 and ERK gene exression levels was determined in K562 cells that are treated with imatinib and silimarin combination. Silimarin as dietary supplement may increase the effect of imatinib and supress the defined cell signalling pathways on drug resistance on CML cells.
Is cervical swab an efficient method for developing a new noninvasive prenatal diagnostic test for numerical and structural chromosome anomalies?
(2021) Yurtcu, Erkan; Karcaaltincaba, Deniz; Kazan, Hasan Huseyin; Ozdemir, Halis; Yirmibes Karaoguz, Meral; Calis, Pinar; Kayhan, Gulsum; Guntekin Ergun, Sezen; Percin, Ferda; Bayram, Merih; Ilhan, Mustafa Necmi; Bilgili, Gamze; Kaymak, Tugrul; Ergun, Mehmet Ali; Is cervical swab an efficient method for developing a new noninvasive prenatal diagnostic test for numerical and structural chromosome anomalies?; 0000-0003-4930-8164; 33315353
Background/aim: Prenatal diagnosis is vital to obtain healthy generation for risky pregnancies. There have been several approaches, some of which are routinely applied in clinics to evaluate the possible prenatal deficiencies and/or diseases. In the present study, we aimed to isolate the fetal cells from endocervical samples and try to identify possible anomalies which were proved by Amniocentesis (AS) and chorionic villus sampling (CVS) methods. Materials and methods: Endoservical specimens were collected from 100 pregnant women. Cells were separated in parallel by fluorescence-activated cell sorting (FACS) and magnetic-activated cell sorting (MACS) using human leukocyte antigen (HLA) G233 and placental alkaline phosphatase (PLAP) antibodies. CMA (comprehensive meta-analysis) were carried out and male fetuses were confirmed with Sex determining region Y (SRY) amplification. Results: The percent of HLA G233 and placental and placental alkaline phosphatase (PLAP) positive cells were 4.55% and 84.59%, respectively. The percent of cells positive for both markers was 14.75%. CMA analyses were not informative. (SRY) was amplified in 67% of the samples. Conclusion: However, the success rate of the both cell sorting and scanning of DNA anomalies by aCGH and/or RT-PCR was limited, preventing the applicability of this proposal in the clinics. Still, the success of the proposed method depends on the development of the novel fetal cell-specific antibodies and the improvements in the sorting systems.
Odontogenic effects of two calcium silicate-based biomaterials in human dental pulp cells
(2018) Onay, Emel Olga; Yurtcu, Erkan; Terzi, Yunus Kasim; Ungor, Mete; Oguz, Yener; Sahin, Feride İffet; 30070078
Background. The goal of treating exposed pulp with an appropriate pulp capping material is to promote the dentinogenic potential of the pulpal cells. There have been recent attempts to develop more effective pulp-capping materials. Objectives. The aim of this study was to evaluate the effect of newly developed calcium silicate-based material on odontogenic differentiation of primary human dental pulp cells (HDPCs), in comparison with a contemporary calcium silicate-based material. Material and methods. Human dental pulp cells isolated from dental pulps were cultured in standard culture conditions in Dulbecco's Modified Eagle's Medium (DMEM) and then the effects of Micro-Mega mineral trioxide aggregate (MM-MTA) (Micro-Mega, Besancon, France) and ProRoot MTA (MTA) (Dentsply Sirona, Tulsa, USA) (positive control) were evaluated on HDPCs at 1, 7 and 14 days. Untreated cells were used as a negative control. Odontoblastic differentiation was assessed by alkaline phosphatase (ALP) activity. Runtrelated transcription factor 2 (RUNX2), alkaline phosphatase liver/bone/kidney (ALPL), bone morphogenetic protein 2 (BMP2), dentin sialophosphoprotein (DSPP), and Distal-less homeobox 3 (DLX3), as odontoblastic/ osteoblastic expression markers, were evaluated by semi-quantitative real-time polymerase chain reaction (RT-PCR) analysis. Calcium levels of culture media were also determined. Results. The MM-MTA group significantly increased the expression of BMP2 compared with that of the MTA group at 3 different time periods (p < 0.05). The up-regulation of ALPL between day 1 and 14 and the up-regulation of DSPP between day 7 and 14 were significant in both groups (p < 0.05). Micro-Mega MTA and MTA exhibited similar messenger RNA (mRNA) expression levels of ALPL, DSPP, RUNX2, DLX3, and ALP activities, as well as calcium levels. Conclusions. Based on the cell responses observed in this study, MM-MTA might be used efficiently in dental pulp therapy as a potential alternative to MTA.
Silymarin: Implications for Antibacterial and Antiadherent Activity
(2014) Evren, Ebru; Yurtcu, Erkan; https://orcid.org/0000-0003-4930-8164; AAA-2998-2021