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Öğe A new low-cost and portable optical device for real-time assessment of tissue microcirculation(Ieee, 2019) Sırcan Küçüksayan, Aslınur; Sırcan, Ahmet Kürşad; Küçüksayan, ErtanIn this work, we have developed a new portable optical device to assess tissue microcirculation. Our system is based on the idea that we can calculate tissue oxygen saturation by analyzing tissue interaction with light at two different wavelengths. The optical device involves measuring the quantitative tissue oxygen saturation value using information obtained from light-tissue interaction with sensors designed to functionally connect to the patient. For this purpose; two LEDs which enable to emission in near-infrared wavelengths and a photodiode which capable of measuring the intensity of the light reflected from the tissue were used with a dedicated hardware and software system. The optical device is fast, reliable and reasonable price considering similar systems. Additionally, it has a user friendly interface and let its users store data in SD Card. The results suggested that the optical device may sensitive to measure the tissue oxygen saturation levels in vivo. The optical system has the potential to improve bedside monitoring device for assessing tissue viability.Öğe A review on melatonin’s effects in cancer: Potential mechanisms(Bentham Science Publishers B.V., 2018) Hanikoğlu, Ayşegül; Küçüksayan, Ertan; Akduman, Rana; Özben, TomrisThis systematic review aims to elucidate the role of melatonin (N-acetyl-5-metoxy-tryptamine) (MLT) in the prevention and treatment of cancer. MLT is a pineal gland secretory product, an evolutionarily highly conserved molecule; it is also an antioxidant and an impressive protector of mitochondrial bioenergetic activity. MLT is characterized by an ample range of activities, modulating the physiology and molecular biology of the cell. Its physiological functions relate principally to the interaction of G Protein-Coupled MT1 and MT2 trans-membrane receptors (GPCRs), a family of guanidine triphosphate binding proteins. MLT has been demonstrated to suppress the growth of various tumours both, in vivo and in vitro. In this review, we analyze in depth, the antioxidant activity of melatonin, aiming to illustrate the cancer treatment potential of the molecule, by limiting or reversing the changes occurring during cancer development and growth. © 2018 Bentham Science Publishers.Öğe Effects of somatostatin and vitamin C on the fatty acid profile of breast cancer cell membranes(Bentham Science Publ Ltd, 2019) Hanikoğlu, Ayşegüll; Küçüksayan, Ertan; Hanikoğlu, Ferhat; Özben, Tomris; Menounou, Georgia; Sansone, Anna; Ferreri, CarlaBackground: Vitamin C (Vit C) is an important physiological antioxidant with growing applications in cancer. Somatostatin (SST) is a natural peptide with growth inhibitory effect in several mammary cancer models. Objective: The combined effects of SST and Vit C supplementation have never been studied in breast cancer cells so far. Methods: We used MCF-7 and MDA-MB231 breast cancer cells incubated with SST for 24h, in the absence and presence of Vit C, at their EC 50 concentrations, to evaluate membrane fatty acid-profiles together with the follow-up of EGFR and MAPK signaling pathways. Results: The two cell lines gave different membrane reorganization: in MCF-7 cells, decrease of omega-6 linoleic acid and increase of omega-3 fatty acids (Fas) occurred after SST and SST+Vit C incubations, the latter also showing significant increases in MUFA, docosapentaenoic acid and mono-trans arachidonic acid levels. In MDA-MB231 cells, SST+Vit C incubation induced significant membrane remodeling with an increase of stearic acid and mono-trans-linoleic acid isomer, diminution of omega-6 linoleic, arachidonic acid and omega-3 (docosapentaenoic and docosadienoic acids). Distinct signaling pathways in these cell lines were studied: in MCF-7 cells, incubations with SST and Vit C, alone or in combination significantly decreased EGFR and MAPK signaling, whereas in MDA-MB231 cells, SST and Vit C incubations, alone or combined, decreased pP44/42 MAPK levels, and increased EGFR levels. Conclusion: Our results showed that SST and Vit C can be combined to induce membrane fatty acid changes, including lipid isomerization through a specific free radical-driven process, influencing signaling pathways.Öğe Effects of somatostatin, curcumin, and quercetin on the fatty acid profile of breast cancer cell membranes(Canadian Science Publishing, 2020) Hanikoğlu, Ayşegül; Küçüksayan, Ertan; Hanikoğlu, Ferhat; Özben, Tomris; Menounou, Georgia; Sansone, Anna; Ferreri, CarlaBreast cancer is a worldwide commonly found malignancy in women and effective treatment is regarded as a huge clinical challenge even in the presence of several treatment options. Extensive literature is available demonstrating polyphenols as phytopharmaceutical anticancer agents. Among the polyphenols, quercetin and curcumin have been reported to have a strong potential against breast cancer. However, so far, no comprehensive study has been performed to demonstrate the anticarcinogenic effects of curcumin, quercetin, and their combinations with somatostatin on the fatty acid profile of breast cancer cell membranes. We used MCF-7 and MDA-MB231 breast cancer cells incubated with curcumin and quercetin for 24 h, in the absence and presence of somatostatin, at their EC50 concentrations to evaluate membrane fatty acid based functional lipidomics together with the followup of EGFR and MAPK signaling pathways. The two cell lines gave different membrane free fatty acid reorganization. In MCF-7 cells, the following changes were observed: an increase of omega 6 linoleic acid in the cells incubated with somatostatin + quercetin and quercetin and a decrease of omega 3 acids in the cells incubated with somatostatin + curcumin compared to somatostatin and significant increases of monounsaturated fatty acid (MUFA), mono-trans arachidonic acid levels and docosapentaenoic acid for the cells incubated with somatostatin + quercetin compared to the control cells. In MDA-MB231 cells, incubations with curcumin, quercetin, and somatostatin + quercetin induced the most significant membrane remodeling with the increase of stearic acid, diminution of omega 6 linoleic, arachidonic acids, and omega 3 (docosapentaenoic and docosahexaenoic acids). Distinct signaling pathway changes were found for these cell lines. In MCF-7 cells, separate or combined incubations with somatostatin and quercetin, significantly decreased EGFR and incubation with curcumin decreased MAPK signaling. In MDA-MB231 cells, incubation with curcumin decreased AKT1 and p-AKT1 (Thr308) levels. Incubation with curcumin and quercetin decreased the EGFR levels. Our results showed that cytostatic and antioxidant treatments can be combined to induce membrane fatty acid changes, including lipid isomerization as specific free radical driven process, and to influence signaling pathways. This study aimed to contribute to the literature on these antioxidants in the treatment of breast cancer to clarify the effects and mechanisms in combination with somatostatin.Öğe Geri Yansıma Spektroskopisi ile Hücre Kültürü Çalışmalarında Hücre Sayısının Belirlenmesi İçin Yeni Bir Metot(2020) Sircan-Kucuksayan, Aslinur; Küçüksayan, ErtanAmaç: Hücre kültürü, hastalıkların teşhisine ve tedavisineyönelik çalışmalarda ve ilaç araştırmalarında en sıkkullanılan yöntemdir. Hücre sayımı ise bu araştırmalardasıklıkla tekrarlanan deneylerin standardizasyonu ve /veya optimizasyonu için önemli bir süreç olarak kabuledilmektedir. Hücre sayımı otomatik hücre sayım cihazlarıile yapılabilmektedir. Ancak bu cihazlar yüksek maliyetve hücre kayıpları gibi dezavantajlara sahiptir. Hücresayısını belirlemenin en ideal yolu hücrelerin ortamlarınıdeğiştirmeden, önemli ölçüde pH veya sıcaklık değişimiyaratmadan hızlı ve doğru ölçüm yapabilmektir. Buçalışmanın amacı hücre kültürü deneylerinde hücre sayısınıbelirlemek için geri yansıma spektroskopisi kullanarak yenibir yöntem geliştirmektir.Materyal-Metot: Bu çalışmada, A375 malin melanomahücreleri standart hücre kültürü tekniği ile çoğaltıldı. Hücresayım cihazı ile sayılan farklı sayıdaki hücreler son hacim1 ml olacak şekilde ayarlandı. Daha sonra spektrometre,tungsten-halojen ışık kaynağı ve fiber optik probtan oluşanbir deney düzeneği kullanıldı. Numuneyle etkileştikten sonrageri yansıyan ışık fiber optik probun dedektör fiberleri iletoplandı geri yansıyan spektrumlar Igor Pro ile analiz edilerekhücre sayısı belirlendi.Bulgular: Farklı hücre sayılarındaki numunelerinspektrumların hücre sayısına bağlı olarak değiştiği belirlendi.Bu spektrumlardan elde edilen K (450-700 nm) parametresinekarşı hücre sayısını veren bir kalibrasyon grafiği bulundu. Buyöntem ile numunelerin hücre sayılarının %1,9-6,5 arasındakihata oranları ile belirlendi.Sonuç: Bu çalışmada fiber optik prob ile dalga boyuna bağlıgeri yansıma ölçümleri yapılarak hücre kültürü koşullarınaminimum müdahale ederek hücre sayısını gerçek zamanlıbelirleyebilen yeni bir yöntem geliştirildi. Bu yöntem hücresayısının zamana bağlı izlenmesine olanak veren invazifolmayan, objektif, tekrarlanabilir ve tecrübe gerektirmeyenbir teknik olarak geliştirilme potansiyeli vardır.Öğe Histopathological and biochemical assessment of a novel diagnostic method for ovarian torsion(Taylor & Francis Ltd, 2020) Özekinci, Murat; Küçüksayan, Ertan; Erdoğan, Gülgün; Aslan, Mutay; Peştereli, Elif; Canpolat, Murat; Sırcan Küçüksayan, AslınurOvarian torsion is agynecologic emergency that affects females of all ages. Early diagnosis is important to preserve ovarian function. The false positive rate for sonographic diagnosis of ovarian torsion is 50%; therefore, a new real-time approach is required to improve diagnostic accuracy. We investigated diffuse reflectance spectroscopy for diagnosing ovarian torsion. Spectroscopic measurements were performed in vivo prior to, during and after detorsion. After bilateral oophorectomy, hemoxygenase and myeloperoxidase enzyme activity in ovarian tissue was evaluated and the tissues were examined for pathology. Spectroscopic data were compared to histopathological and biochemical data to assess the diagnostic value of the spectroscopic method for differentiating healthy and damaged ovarian tissue. We found a good correlation between spectroscopy and histopathology. We also found a correlation between the spectroscopic data and heme oxygenase enzyme activity. We found no correlation between the histopathological tissue damage score and myeloperoxidase enzyme activity. Diffuse reflectance spectroscopy may be of prognostic and diagnostic value for ovarian torsion in vivo.Öğe Investigation of the Effect of Prophylactic Gastropexy Techniques on Gastrin Hormone and Pancreatic Enzyme Levels in Dogs(Sivas Cumhuriyet Üniversitesi, 2022) İncekara, Osman; Küçüksayan, Ertan; Arıcan, MustafaThe advantages and disadvantages of the techniques were investigated by applying prophylactic endoscopic gastropexy, laparoscopic gastropexy and ventral midline gastropexy techniques to 15 dogs predisposed to gastric dilatation volvulus problem, and comparing the changes in the levels of amylase, lipase and gastrin secreted from the stomach and pancreas during the recovery period. In the study, 15 dogs were divided into 3 groups for mid-ventral line, laparoscopic and endoscopically assisted gastropexy. Classic gastropexy was performed in 5 dogs in the first group, laparoscopic assisted gastropexy in the dogs in the second group, and endoscopic gastropexy in the dogs in the third group. Preoperative, postoperative 1st day and 8th day amylase, lipase and gastrin measurements were made for the dogs in each group and the data obtained were evaluated statistically. At the end of the operation, no clinical pathology was found. The obtained amylase, lipase and gastrin levels were also within the range of normal standard references. As a result, it supports the fact that the operation techniques performed in terms of enzyme releases do not have a statistical advantage over each other. Even though the techniques have advantages and disadvantages to each other in terms of application and time, it has been argued that any of these three techniques will not make a statistical difference in terms of the enzymatic results of amylase, lipase and gastrin enzymes, and that all three techniques can be used for prophylactic purposes. However, it is thought that changes in enzymatic and gastric motility may occur with a longer post-operative period. In this respect, a longer post-operative period should be evaluated with more cases.Öğe Melanoma hücrelerinde epoksomisinin indüklediği apoptozis sürecinde gerçekleşen erken spektral değişikliklerin belirlenmesi(2021) Küçüksayan, Ertan; Sırcan Küçüksayan, AslınurAmaç: Hücrelerde apoptozis sürecinde meydana gelen spektral değişikliklerin belirlenmesi yeni tedavi ve ilaç araştırmalarına önemli bilgiler sağlayabilir. Apoptotik hücreler, hücre küçülmesi ve parçalanmasına yol açan bir dizi hücre altı değişikliğe uğrar. Apoptotik süreçte bu değişimlerin erken aşamada zamana bağlı olarak belirlenmesi hücre kültürü çalışmalarına yeni bir yön verebilir. Bu çalışmanın amacı melanoma hücrelerinin apoptozis sürecinde erken aşamada meydana gelen spektral değişikliklerin zamana bağlı olarak belirlenebileceği bir yöntem geliştirmektir. Yöntem: Bu çalışmada A375 melanoma hücre hattında apoptozisi indüklemek için epoksomisin (Epo) kullanılmıştır ve apoptotik doz MTT yöntemi ile belirlenmiştir. Erken apoptotik sürecinin zamana bağlı değerlendirilebilmesi için sabit Epo dozuyla beş farklı zaman noktasında (0.5-6 saat) ölçümler yapılmıştır. Apoptozisin en önemli uyaranı olan ROS ölçümü DCFH-DA yöntemi ile yapılmıştır. Western Blot tekniği ile Bax miktarı belirlenmiştir. Geri yansıma spektroskopisi sistemi ile ölçülen spektrumlardan spektroskopik apoptozis indeksi belirlenmiştir. Bulgular: Melanoma hücrelerinin apoptozis süresinde ölçülen spektrumlar ile erken spektral değişiklikler belirlenmiştir. ROS ölçümlerinde 2., 4. ve 6. saat ölçümlerinde kontrole göre anlamlı fark bulunmuştur. Hücre canlılığının 24 saat sonra 75 ve 100 nM Epo dozlarında kontrole göre %70 azaldığı bulunmuştur. Apoptozisin bir göstergesi olarak tüm Epo gruplarında zamana bağlı olarak Bax seviyelerinin arttığı bulunmuştur. Spektroskopik apoptozis indeks değeri tüm gruplarda ROS ve Bax sonuçları ile uyumlu bulunmuştur. Sonuç: Hücre kültüründe apoptozis sürecinde erken aşamada meydana gelen spektral değişikliklerin geri yansıma spektroskopisi ile belirlenebileceği yeni bir yaklaşım sunulmuştur. Bu yaklaşımın hücre kültürü çalışmalarında apoptozisi hücre kültürü koşullarına müdahale etmeden, zamana bağlı olarak izleyebilen bir yöntem olarak geliştirilme potansiyeli vardır.Öğe Plasma thiol/disulphide homeostasis changes in patients with relapsing-remitting multiple sclerosis(2021) Özben, Serkan; Küçüksayan, Ertan; Köseoğlu, Mesrure; Erel, Özcan; Neşelioğlu, Salim; Özben, TomrisBackground: Multiple sclerosis (MS) is a neuroinflammatory disease and inflammation and oxidative stress play important roles in its pathology. Thiol/disulphide homeostasis (TDH) is a special oxidative stress biomarker that has been found to be affected in several disorders including MS. There is no study demonstrating the effects of attack status of the relapsing-remitting multiple sclerosis (RRMS) patients on TDH levels. Our aim was to determine TDH levels in three different periods of RRMS patients and healthy individuals. Methods: The study was carried out in 29 patients with RRMS without a prior attack in the last twelve months (MS Control), 21 RRMS patients having a clinical acute attack within the last week (MS relapse), 12 of 21 MS relapse patients one month after the onset of attack and following 1000 mg methylprednisolone for 7 days (MS Remission) and 30 age- and sex-matched healthy individuals. TDH status was determined using an automated spectrophotometric analysis method. TDH levels in all patient groups and control subjects were compared with each other. Results: The lowest native thiol, total thiol levels and native thiol/total thiol ratio were found in the MS relapse patients in comparison to the MS control, MS remission groups and healthy controls. In contrast, disulphide levels, disulphide/native thiol and disulphide/total thiol ratios were highest in the MS relapse group compared to the other patient groups and healthy subjects. Conclusion: Our findings indicate that increased oxidative stress in RRMS patients is reflected with decreased native and total thiol and increased disulphide levels. Since the formation of disulphide bonds is reversible, the progression of RRMS involving abnormal TDH may be controlled, converting disulphides to thiols. So, we suggest determining the dynamic TDH status as a novel and special biomarker in the diagnosis and prognosis of the RRMS patients. What’s known • Multiple sclerosis (MS) is a neuroinflammatory disease and inflammation and oxidative stress play important roles in its pathology. • Like other inflammatory diseases, oxidative stress is associated with MS playing an important role in the pathogenesis of MS. What’s new • Our study provides original data on dynamic Thiol/disulphide homeostasis (TDH) status in the relapsing-remitting multiple sclerosis (RRMS) patients at three different periods of the disease and examines whether plasma TDH can be used as a special oxidative stress biomarker in the diagnosis and follow-up of the RRMS patients and their response to the therapyÖğe Real-Time Detection of Doxorubicin-InducedApoptosis in Breast Cancer Cells Using the BackReflection Spectroscopy(2021) Küçüksayan, Ertan; Sırcan Küçüksayan, AslınurApoptosis detection methods cause the cell culture medium to be physically or chemically affected. In addition, these methods have disadvantages such as cost and cell losses. The aim of this study is to develop a method to assess apoptosis in real-time using the back-reflection spectroscopy (BRS) in breast cancer cells.BRS experiment set up consists of a spectrometer, a tungsten-halogen light source and a fiber optic probe. In order to assess the changes associated with apoptosis, the intensity of the reflected light was measured with a fiber -optic probe from MCF7 breast cancer cell samples in which apoptosis induced doxorubicin. Spectroscopic measurements were performed 6 hours after incubation from control and doxorubicin groups. Cell viability measurement with MTT method, imaging of cell morphology with toluidine blue staining method, ROS measurement with DCFH-DA method were performed for the evaluation of apoptosis.We analyzed the back reflection spectrum and determined the signal difference in apoptotic cell samples compared to the control. A significant difference was found in ROS measurements in all groups compared to the control. We did not observe any morphological change in the cells imaged with the toluidine blue method for 6 hours. Cell viability decreased 50% in all groups compared to the control for 24 hours.BRS is a new approach that may detect apoptosis in real time without interfering cell culture conditions. This method has the potential to be developed as a non-invasive, objective and reproducible technique that enables time -dependent monitoring of apoptosis.Öğe Sapienic Acid Metabolism Influences Membrane Plasticity and Protein Signaling in Breast Cancer Cell Lines(2022) Küçüksayan, Ertan; Sansone, Anna; Chatgilialoglu, Chryssostomos; Özben, Tomris; Tekeli, Demet; Talibova, Günel; Ferreri, CarlaAbstract: The importance of sapienic acid (6c-16:1), a monounsaturated fatty acid of the n-10 family formed from palmitic acid by delta-6 desaturase, and of its metabolism to 8c-18:1 and sebaleic acid (5c,8c-18:2) has been recently assessed in cancer. Data are lacking on the association between signaling cascades and exposure to sapienic acid comparing cell lines of the same cancer type. We used 50 µM sapienic acid supplementation, a non-toxic concentration, to cultivate MCF-7 and 2 triplenegative breast cancer cells (TNBC), MDA-MB-231 and BT-20. We followed up for three hours regarding membrane fatty acid remodeling by fatty acid-based membrane lipidome analysis and expression/phosphorylation of EGFR (epithelial growth factor receptor), mTOR (mammalian target of rapamycin) and AKT (protein kinase B) by Western blotting as an oncogenic signaling cascade. Results evidenced consistent differences among the three cell lines in the metabolism of n-10 fatty acids and signaling. Here, a new scenario is proposed for the role of sapienic acid: one based on changes in membrane composition and properties, and the other based on changes in expression/activation of growth factors and signaling cascades. This knowledge can indicate additional players and synergies in breast cancer cell metabolism, inspiring translational applications of tailored membrane lipid strategies to assist pharmacological interventions.
