Browsing by Author "Aktug, Huseyin"

Now showing 1 - 12 of 12

Autophagy and Mtor Pathways in Mouse Embryonic Stem Cell, Lung Cancer and Somatic Fibroblast Cell Lines
(Wiley, 2019) Oltulu, Fatih; Kocaturk, Duygu C.; Adali, Yasemin; Ozdil, Berrin; Acikgoz, Eda; Gurel, Cevik; Aktug, Huseyin
Embryonic developmental stages and regulations have always been one of the most intriguing aspects of science. Since the cancer stem cell discovery, striking for cancer development and recurrence, embryonic stem cells and control mechanisms, as well as cancer cells and cancer stem cell control mechanisms become important research materials. It is necessary to reveal the similarities and differences between somatic and cancer cells which are formed of embryonic stem cells divisions and determinations. For this purpose, mouse embryonic stem cells (mESCs), mouse skin fibroblast cells (MSFs) and mouse lung squamous cancer cells (SqLCCs) were grown in vitro and the differences between these three cell lines signalling regulations of mechanistic target of rapamycin (mTOR) and autophagic pathways were demonstrated by immunofluorescence and real-time polymerase chain reaction. Expressional differences were clearly shown between embryonic, cancer and somatic cells that mESCs displayed higher expressional level of Atg10, Hdac1 and Cln3 which are related with autophagic regulation and Hsp4, Prkca, Rhoa and ribosomal S6 genes related with mTOR activity. LC3 and mTOR protein levels were lower in mESCs than MSFs. Thus, the mechanisms of embryonic stem cell regulation results in the formation of somatic tissues whereas that these cells may be the causative agents of cancer in any deterioration.
Comparison of Cell Cycle Components, Apoptosis and Cytoskeleton-Related Molecules and Therapeutic Effects of Flavopiridol and Geldanamycin on the Mouse Fibroblast, Lung Cancer and Embryonic Stem Cells
(Sage Publications Ltd, 2016) Aktug, Huseyin; Acikgoz, Eda; Uysal, Aysegul; Oltulu, Fatih; Oktem, Gulperi; Yigitturk, Gurkan; Cetintas, Vildan Bozok
Similarities and differences in the cell cycle components, apoptosis and cytoskeleton-related molecules among mouse skin fibroblast cells (MSFs), mouse squamous cell lung carcinomas (SqCLCs) and mouse embryonic stem cells (mESCs) are important determinants of the behaviour and differentiation capacity of these cells. To reveal apoptotic pathways and to examine the distribution and the role of cell cycle-cell skeleton comparatively would necessitate tumour biology and stem cell biology to be assessed together in terms of oncogenesis and embryogenesis. The primary objectives of this study are to investigate the effects of flavopiridol, a cell cycle inhibitor, and geldanamycin, a heat shock protein inhibitor on mouse somatic, tumour and embryonic stem cells, by specifically focusing on alterations in cytoskeletal proteins, cell polarity and motility as well as cell cycle regulators. To meet these objectives, expression of several genes, cell cycle analysis and immunofluorescence staining of intracellular cytoskeletal molecules were performed in untreated and flavopiridol- or geldanamycin-treated cell lines. Cytotoxicity assays showed that SqCLCs are more sensitive to flavopiridol than MSFs and mESCs. Keratin-9 and keratin-2 expressions increased dramatically whereas cell cycle regulatory genes decreased significantly in the flavopiridol-treated MSFs. Flavopiridol-treated SqCLCs displayed a slight increase in several cell cytoskeleton regulatory genes as well as cell cycle regulatory genes. However, gene expression profiles of mESCs were not affected after flavopiridol treatment except the Cdc2a. Cytotoxic concentrations of geldanamycin were close to each other for all cell lines. Cdkn1a was the most increased gene in the geldanamycin-treated MSFs. However, expression levels of cell cytoskeleton-associated genes were increased dramatically in the geldanamycin-treated SqCLCs. Our results revealing differences in molecular mechanisms between embryogenesis and carcinogenesis may prove crucial in developing novel therapeutics that specifically target cancer cells.
Deciphering the Biochemical Similarities and Differences Among Mouse Embryonic Stem Cells, Somatic and Cancer Cells Using Atr-Ftir Spectroscopy
(Royal Soc Chemistry, 2018) Guler, Gunnur; Acikgoz, Eda; Yavasoglu, N. Ulku Karabay; Bakan, Buket; Goormaghtigh, Erik; Aktug, Huseyin
Cellular macromolecules play important roles in cellular behaviors and biological processes. In the current work, cancer (KLN205), normal (MSFs) and mouse embryonic stem cells (mESCs) are compared using ATR-FTIR spectroscopy. Modifications in the composition, concentration, structure and function-related changes in the cellular components were deciphered using the infrared spectra. Our results revealed that cancer and embryonic stem cells are very similar but highly different from the normal cells based on the spectral variations in the protein, lipid, carbohydrate and nucleic acid components. The longest lipid acyl chains exist in mESCs, while cancer cells harbor the lowest lipid amount, short lipid acyl chains, a high content of branched fatty acids and thin cell membranes. The highest cellular growth rate and accelerated cell divisions were observed in the cancer cells. However, the normal cells harbor low nucleic acid and glycogen amounts but have a higher lipid composition. Any defect in the signaling pathways and/or biosynthesis of these cellular parameters during the embryonic-to-somatic cell transition may lead to physiological and molecular events that promote cancer initiation, progression and drug resistance. We conclude that an improved understanding of both similarities and differences in the cellular mechanisms among the cancer, normal and mESCs is crucial to develop a potential clinical relevance, and ATR-FITR can be successfully used as a novel approach to gain new insights into the stem cell and cancer research. We suggest that targeting the cellular metabolisms (glycogen and lipid) can provide new strategies for cancer treatment.
Deneysel Diabet Modeli Oluşturulan Farelerde Tirozin Kinaz İnhibitör Uygulanımının Testis Dokusu Üzerine Olan Etkilerinin Pluripotensi Kapasitesi ve Hücre Adezyonu Özelinde Araştırılması
(2017) Oktem, Gulperi; Demir, Kenan; Aktug, Huseyin; Yigitturk, Gurkan; Yavaşoğlu, Altuğ; Özdedeli, Kaan; Açıkgöz, Eda
Amaç: Tirozin kinaz inhibisyonunun diyabet etkisi altındaki testis dokusu üzerine göstereceği etkileri araştırmaktır. Gereç ve Yöntem: Çalışmamızda 31 adet CD1 türü erkek fare kullanıldı ve dört gruba ayrıldı: Grup 1'de (kontrol grubu) 7, Grup 2'de tirozin kinaz inhibitörü uygulanan 7, Grup 3'te diyabetik ve SF uygulanan 8, Grup 4'te diyabet + tirozin kinaz inhibitörü uygulanan 9 denek hayvanı yer aldı. Grup 1'de herhangi bir uygulama yapılmadı. Grup 2'deki farelere 3 hafta boyunca tirozin kinaz inhibitörü verildi. Diyabet oluşturulması için 0.1mol/L tek doz streptozotosinin intraperitoneal olarak verildi. 250 mg/dL ve üzeri kan glikoz seviyesi diyabetik olarak kabul edildi. Deneysel diyabet modeli oluşturulan farelere 1 hafta beklendikten sonra, Grup 3'e SF, Grup 4'e 3 hafta boyunca tirozin kinaz inhibitörü verildi. Sonunda tüm denek hayvanları anestezi altında sakrifiye edilerek histopatolojik inceleme için testis dokuları alındı. İstatistiksel analiz için tek yönlü varyans analizi (ANOVA) testi yapıldı, 0.05'ten küçük p değerleri, istatistiksel olarak anlamlı kabul edildi. Bulgular: Testis dokusu histopatolojik olarak incelendiğinde deneysel diyabete bağlı olarak seminifer tübülün germ hücre serilerinde kayıp, hücre bütünlüklerinde ise bozulma saptandı. Sonuç: Bu çalışma, diyabetin testiste germ hücre serilerinde sayısal olarak azalmaya ve hücre adezyon mekanizmasında bozulmaya yol açtığını göstermektedir. Tirozin kinaz inhibitörü uygulamasının, bu hasarlanmada tamir edici etkisinin olduğu düşünülmektedir. Bu hasarın tedavisinin derecesi, uygulanan tirozin kinaz inhibitörünün dozu ve süresine bağlı olarak farklılık gösterebilmektedir. Ancak, klinik diyabet uygulamalarında tirozin kinaz inhibitörü kullanılabilmesi için bu konuda moleküler çalışma sayılarının artışına ihtiyaç vardır.
Differences and Similarities Between Colorectal Cancer Cells and Colorectal Cancer Stem Cells: Molecular Insights and Implications
(Amer Chemical Soc, 2023) Erisik, Derya; Ozdil, Berrin; Acikgoz, Eda; Asker Abdikan, Cemile Sinem; Yesin, Taha Kadir; Aktug, Huseyin
Malignant tumors are formed by diverse groups of cancercells.Cancer stem cells (CSCs) are a subpopulation of heterogeneous cellsidentified in tumors that have the ability to self-renew and differentiate.Colorectal cancer (CRC), the third most frequent malignant tumor,is progressively being supported by evidence suggesting that CSCsare crucial in cancer development. We aim to identify molecular differencesbetween CRC cells and CRC CSCs, as well as the effects of those differenceson cell behavior in terms of migration, EMT, pluripotency, morphology,cell cycle/control, and epigenetic characteristics. The HT-29 cellline (human colorectal adenocarcinoma) and HT-29 CSCs (HT-29 CD133(+)/CD44(+) cells) were cultured for 72 h. The levelsof E-cadherin, KLF4, p53, p21, p16, cyclin D2, HDAC9, and P300 proteinexpression were determined using immunohistochemistry staining. Themigration of cells was assessed by employing the scratch assay technique.Additionally, the scanning electron microscopy method was used toexamine the morphological features of the cells, and their peripheral/centralelemental ratios were compared with the help of EDS. Furthermore,a Muse cell cycle kit was utilized to determine the cell cycle analysis.The HT-29 CSC group exhibited high levels of expression for E-cadherin,p53, p21, p16, cyclin D2, HDAC9, and P300, whereas KLF4 was foundto be high in the HT-29. The two groups did not exhibit any statisticallysignificant differences in the percentages of cell cycle phases. Theidentification of specific CSC characteristics will allow for earliercancer detection and the development of more effective precision oncologyoptions.
Differences and Similarities in Biophysical and Biological Characteristics Between U87 Mg Glioblastoma and Astrocyte Cells
(Springer, 2024) Ozdil, Berrin; Calik-Kocaturk, Duygu; Altunayar-Unsalan, Cisem; Acikgoz, Eda; Oltulu, Fatih; Gorgulu, Volkan; Aktug, Huseyin
Current cancer studies focus on molecular-targeting diagnostics and interactions with surroundings; however, there are still gaps in characterization based on topological differences and elemental composition. Glioblastoma (GBM cells; GBMCs) is an astrocytic aggressive brain tumor. At the molecular level, GBMCs and astrocytes may differ, and cell elemental/topological analysis is critical for identifying potential new cancer targets. Here, we used U87 MG cells for GBMCS. U87 MG cell lines, which are frequently used in glioblastoma research, are an important tool for studying the various features and underlying mechanisms of this aggressive brain tumor. For the first time, atomic force microscopy (AFM), scanning electron microscopy (SEM) accompanied by energy-dispersive X-ray spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS) are used to report the topology and chemistry of cancer (U87 MG) and healthy (SVG p12) cells. In addition, F-actin staining and cytoskeleton-based gene expression analyses were performed. The degree of gene expression for genes related to the cytoskeleton was similar; however, the intensity of F-actin, anisotropy values, and invasion-related genes were different. Morphologically, GBMCs were longer and narrower while astrocytes were shorter and more disseminated based on AFM. Furthermore, the roughness values of these cells differed slightly between the two call types. In contrast to the rougher astrocyte surfaces in the lamellipodial area, SEM-EDS analysis showed that elongated GBMCs displayed filopodial protrusions. Our investigation provides considerable further insight into rapid cancer cell characterization in terms of a combinatorial spectroscopic and microscopic approach.
The Effect of Extracellular Matrix on the Differentiation of Mouse Embryonic Stem Cells
(Wiley, 2020) Ozdil, Berrin; Guler, Gunnur; Acikgoz, Eda; Kocaturk, Duygu Calik; Aktug, Huseyin
Embryonic stem cells (ESCs) are promising research materials to investigate cell fate determination since they have the capability to differentiate. Stem cell differentiation has been extensively studied with various microenvironment mimicking structures to modify cellular dynamics associated with the cell-extracellular matrix (ECM) interactions and cell-cell communications. In the current study, our aim was to determine the effect of microenvironmental proteins with different concentrations on the capacity and differentiation capability of mouse ESCs (mESCs), combining the biochemical assays, imaging techniques, Fourier transform infrared (FTIR) spectroscopy, and unsupervised multivariate analysis. Based on our data, coating the surface of mESCs with Matrigel, used as an acellular matrix substrate, resulted in morphological and biochemical changes. mESCs exhibited alterations in their phenotype after growing on the Matrigel-coated surfaces, including their differentiation capacity, cell cycle phase pattern, membrane fluidity, and metabolic activities. In conclusion, mESCs can be stimulated physiologically, chemically, or mechanically to convert them a new phenotype. Thus, identification of ESCs' behavior in the acellular microenvironment could be vital to elucidate the mechanism of diseases. It might also be promising to control the cell fate in the field of tissue engineering.
Effects of Flavopiridol on Critical Regulation Pathways of Cd133high Lung Cancer Stem Cells
(Lippincott Williams & Wilkins, 2016) Cetintas, Vildan Bozok; Acikgoz, Eda; Yigitturk, Gurkan; Demir, Kenan; Oktem, Gulperi; Kaymaz, Burcin Tezcanli; Aktug, Huseyin
Background:Flavopiridol a semisynthetic flavone that inhibits cyclin-dependent kinases (CDKs) and has growth-inhibitory activity and induces a blockade of cell-cycle progression at G1-phase and apoptosis in numerous human tumor cell lines and is currently under investigation in phase II clinical trials. Cancer stem cells (CSCs) are comprised of subpopulation of cells in tumors that have been proposed to be responsible for recurrence and resistance to chemotherapy. The aim of the present study was to investigate the effects of flavopiridol in cancer stem cell cytoskeleton, cell adhesion, and epithelial to mesenchymal transition in CSCs.Methods:The cells were treated with flavopiridol to determine the inhibitory effect. Cell viability and proliferation were determined by using the WST-1 assay. Caspase activity and immunofluorescence analyses were performed for the evaluation of apoptosis, cell cytoskeleton, and epithelial-mesenchymal transition (EMT) markers. The effects of flavopiridol on the cell cycle were also evaluated. Flow cytometric analysis was used to detect the percentages of CSCs subpopulation. We analyzed the gene expression patterns to predict cell cycle and cell cytoskeleton in CSCs by RT-PCR.Results:Flavopiridol-induced cytotoxicity and apoptosis at the IC50 dose, resulting in a significant increase expression of caspases activity. Cell cycle analyses revealed that flavopiridol induces G1 phase cell cycle arrest. Flavopiridol significantly decreased the mRNA expressions of the genes that regulate the cell cytoskeleton and cell cycle components and cell motility in CSCs.Conclusion:Our results suggest that Flavopiridol has activity against lung CSCs and may be effective chemotherapeutic molecule for lung cancer treatment.
Glycogen Synthase Kinase-3 Inhibition in Glioblastoma Multiforme Cells Induces Apoptosis, Cell Cycle Arrest and Changing Biomolecular Structure
(Pergamon-elsevier Science Ltd, 2019) Acikgoz, Eda; Guler, Gunnur; Camlar, Mahmut; Oktem, Gulperi; Aktug, Huseyin
Glioblastoma multiforme (GBM) is the most malignant and aggressive primary human brain tumors. The regulatory pathways of apoptosis are altered in GBMs, leading to a survival advantage of the tumor cells. Thus, identification of target molecules, which are effective in triggering of the cell death mechanisms in GBM, is an essential strategy for therapeutic purposes. Glycogen synthase kinase-3 (GSK-3) plays an important role in apoptosis, proliferation and cell cycle. This study focused on the effect of GSK-3 inhibitor IX in the GBM cells. Apoptosis induction was determined by Annexin-V assay, multicaspase activity and immunofluorescence analyses. Concentration-dependent effects of GSK-3 inhibitor IX on the cell cycle were also evaluated. Moreover, the effect of GSK inhibitor on the cellular biomolecules was assessed by using ATR-FTIR spectroscopy. Our assay results indicated that GSK-3 inhibitor IX induces apoptosis, resulting in a significant increase in the expression of caspase-3 and caspase-8 proteins. Cell cycle analyses revealed that GSK-3 inhibitor IX leads to dose -dependent G2/M-phase cell cycle arrest. Based on the FTIR data, treatment of GBM cells causes dysregulation in the carbohydrate metabolism and induces apoptotic cell death which was characterized by the spectral alterations in nucleic acids, an increment in the lipid amount with disordering state and compositional changes in the cellular proteins. These findings suggest that GSK-3 inhibitor IX exhibits anti-cancer effects by inducing apoptosis and changing biomolecular structure of membrane lipids, carbohydrates, nucleic acids and proteins, and thus, may be further evaluated as a potential effective candidate agent for the GBM combination therapies. (C) 2018 Elsevier B.V. All rights reserved.
Prostat Kanseri Hücreleri'nde D-amino Nöraminik Asidin Gangliozid'e Spesifik Bağlanmasının Çalışılması
(2023) Yigitturk, Gurkan; Rouhrazi, Hadi; Aktug, Huseyin; Güler, Günnur; Demir, Kenan; Acıkgoz, Eda
Amaç: Bu çalışmanın amacı, insan D-Amino Nöraminik Asid’inin (KDN, 2-keto-3-deoksi-D-glisero-D galakto-nononik asit) hücresel bağlanma bölgesini araştırmaktır. KDN molekülü, sialik asit ailesinin bir üyesidir ve kanser hücrelerinde ekspresyonu artar. KDN'nin alabalık sperminde Monosialodihexosyl Gangliosid’e (GM3) bağlandığı gösterilmiştir. Gereç ve Yöntem: Bu çalışmada bir prostat kanseri hücre dizisi (DU145) kullanıldı. Her deney grubu; Kontrol, Glukosilseramid sentaz (GCS) enzim inhibitörü Genz-123346 ile tedavi edilen ve GM3 sentez inhibitörü Triptolid ile tedavi edilen olmak üzere 3 gruba ayrıldı. Her grup, GM3, Disialosyllactosylceramide (GD3) ve KDN için immünositokimyasal yöntem kullanılarak boyandı. Tedaviden sonra hücresel değişikliklerin sağlaması Fourier Transform Infrared (FTIR) Spektroskopi analizi ile yapıldı. Bulgular: Tedavi edilmeyen 1 numaralı hücre grubu, GM3, GD3 ve KDN ile pozitif boyandı ve GCS enzimi, sadece KDN ile pozitif boyanan 2 numaralı hücrelerin Genz-123346 grubuyla bloke edildi. Ayrıca, GD3 sentaz inhibitörü Triptolide ile muamele edilmiş 3 numaralı hücre grubu, GM3 ve KDN ile pozitif boyandı. FTIR ölçümleri Triptolide ile apoptotik özellikler gösterirken, Genz-123346 hücre canlılığı üzerinde olumsuz bir etkiye sahip değildi. Şeker yapılarında azalma ortaya çıktı ve immunositokimyasal boyama ile elde ettiğimiz sonuçlar FTIR ile pekiştirildi. Sonuç: KDN'nin yerinin belirlenmesi, kanser tedavisi araştırmaları için yeni hedeflerin seçilmesi açısından önemlidir. KDN'nin GM3 inhibisyonu ve GD3 inhibisyonu tarafından inhibe edilmediği gösterilmiştir. KDN, GM3 üzerinde olabileceği gibi farklı yerlere de bağlanabilir veya serbest halde olabilir. Bu çalışmada yalnızca salt GM veya GD serisindeki gangliozidlerden herhangi birine bağlanmayacağı ortaya konulmuştur.
Repression of the Notch Pathway Prevents Liver Damage in Streptozotocin-Induced Diabetic Mice
(Via Medica, 2017) Acikgoz, Eda; Aktug, Huseyin; Yigitturk, Gurkan; Demir, Kenan; Guven, Ummu; Duzagac, Fahriye; Oktem, Gulperi
Introduction. Sunitinib is an oral inhibitor of vascular endothelial growth factor that is used to treat a variety of cancer. There are limited data regarding the effect of sunitinib on diabetes. In the liver, Notch signaling plays an important role in liver tissue development and homeostasis and its dysfunction is associated with liver pathologies. The aim of the present study is to investigate the effects of sunitinib on streptozotocin (STZ)-induced diabetic liver in mice models. Material and methods. An experimental diabetes mellitus (DM) model was created in 28 male CD-1 mice. Twenty-eight male CD-1 mice divided in four groups (n = 7 each) were used; control mice (C), control mice treated with sunitinib (C + S), diabetic mice (DM), and diabetic mice treated with sunitinib (DM + S) for four weeks. The histopathological changes in the liver were examined by histochemistry and immunohistochemistry. Immunoreactivity of Notch1, Jagged1, DLL-1 and VEGF were evaluated in control and diabetic mice after sunitinib treatment. Results. The significant morphological changes in the liver were mostly seen in hepatocytes that were hypertrophied in the DM mice, with an increased amount of eosinophilic granules; moreover, some hepatocytes contained empty vacuole-like structures. The livers of the DM mice revealed increased deposition of collagen fibers. After sunitinib treatment the hepatocytes and hepatic lobules had almost similar morphology to control mice. The immunoreactivities of Notch1, Jagged1, DLL-1 and VEGF in hepatocytes were significantly lower in the DM group when compared with the C, DM + S and C + S group treated with sunitinib. Conclusions. These results suggest that sunitinib effectively protects the liver from diabetes-induced damage through the inhibition of the Notch pathway.
Spectroscopic and Microscopic Comparisons of Cell Topology and Chemistry Analysis of Mouse Embryonic Stem Cell, Somatic Cell and Cancer Cell
(Elsevier Gmbh, 2021) Ozdil, Berrin; Calik-Kocaturk, Duygu; Altunayar-Unsalan, Cisem; Acikgoz, Eda; Gorgulu, Volkan; Uysal, Aysegul; Aktug, Huseyin
While embryonic stem cells and cancer cells are known to have many similarities in signalling pathways, healthy somatic cells are known to be different in many ways. Characterization of embryonic stem cell is crucial for cancer development and cancer recurrence due to the shared signalling pathways and life course with cancer initiator and cancer stem cells. Since embryonic stem cells are the sources of the somatic and cancer cells, it is necessary to reveal the relevance between them. The past decade has seen the importance of interdisciplinary studies and it is obvious that the reflection of the physical/chemical phenomena occurring on the cell biology has attracted much more attention. For this reason, the aim of this study is to elementally and topologically characterize the mouse embryonic stem cells, mouse lung squamous cancer cells, and mouse skin fibroblast cells by using Atomic Force Microscopy (AFM), X-ray Photoelectron Spectroscopy (XPS) and Scanning Electron Microscopy (SEM) supported with Electron Dispersive Spectroscopy (EDS) techniques in a complementary way. Our AFM findings revealed that roughness data of the mouse embryonic stem cells and cancer cells were similar and somatic cells were found to be statistically different from these two cell types. However, based on both XPS and SEM-EDS results, surface elemental ratios vary in mouse embryonic stem cells, cancer cells and somatic cells. Our results showed that these complementary spectroscopic and microscopic techniques used in this work are very effective in cancer and stem cell characterization and have the potential to gather more detailed information on relevant biological samples.