Browsing by Author "Acikgoz, Eda"

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Adaptive Phenotypic Modulations Lead To Therapy Resistance in Chronic Myeloid Leukemia Cells
(Public Library Science, 2020) Baykal-Kose, Seda; Acikgoz, Eda; Yavuz, Ahmet Sinan; Geyik, Oyku Gonul; Ate, Halil; Sezerman, Osman Ugur; Yuce, Zeynep
Tyrosine kinase inhibitor (TKI) resistance is a major problem in chronic myeloid leukemia (CML). We generated a TKI-resistant K562 sub-population, K562-IR, under selective imatinib-mesylate pressure. K562-IR cells are CD34(-)/CD38(-), BCR-Abl-independent, proliferate slowly, highly adherent and form intact tumor spheroids. Loss of CD45 and other hematopoietic markers reveal these cells have diverged from their hematopoietic origin. CD34 negativity, high expression of E-cadherin and CD44; decreased levels of CD45 and beta-catenin do not fully confer with the leukemic stem cell (LSC) phenotype. Expression analyses reveal that K562-IR cells differentially express tissue/ organ development and differentiation genes. Our data suggest that the observed phenotypic shift is an adaptive process rendering cells under TKI stress to become oncogene independent. Cells develop transcriptional instability in search for a gene expression framework suitable for new environmental stresses, resulting in an adaptive phenotypic shift in which some cells partially display LSC-like properties. With leukemic/cancer stem cell targeted therapies underway, the difference between treating an entity and a spectrum of dynamic cellular states will have conclusive effects on the outcome.
Age-Related Characterization of Dental Pulp Mesenchymal Stem Cells
(Wiley, 2023) Kaya, Egemen; Acikgoz, Eda; Aydogdu, Ilkay; Dindaroglu, Funda Cagirir; Atalayin, Cigdem; Oktem, Gulperi
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.
Biomolecular Fingerprints of the Effect of Zoledronic Acid on Prostate Cancer Stem Cells: Comparison of 2d and 3d Cell Culture Models
(Elsevier Science inc, 2024) Guler, Gunnur; Acikgoz, Eda; Mukhtarova, Guenel; Oktem, Gulperi
Revealing the potential of candidate drugs against different cancer types without disrupting normal cells depends on the drug mode of action. In the current study, the drug response of prostate cancer stem cells (PCSCs) to zoledronic acid (ZOL) grown in two-dimensional (2D) and three-dimensional (3D) culture systems was compared using Fourier transform-infrared (FT-IR) spectroscopy which is a vibrational spectroscopic technique, supporting by biochemical assays and imaging techniques. Based on our data, in 2D cell culture conditions, the ZOL treatment of PCSCs isolated according to both C133 and CD44 cell surface properties induced early/late apoptosis and suppressed migration ability. The CD133 gene expression and protein levels were altered, depending on culture systems. CD133 expression was significantly reduced in 2D cells upon ZOL treatment. FT-IR data revealed that the integrity, fluidity, and ordering/disordering states of the cell membrane and nucleic acid content were altered in both 2D and 3D cells after ZOL treatment. Regular protein structures decrease in 2D cells while glycogen and protein contents increase in 3D cells, indicating a more pronounced cytotoxic effect of ZOL for 2D cells. Untreated 3D PCSCs exhibited an even different spectral profile associated with IR signals of lipids, proteins, nucleic acids, and glycogen in comparison to untreated 2D cells. Our study revealed significant differences in the drug response and cellular constituents between 2D and 3D cells. Exploring molecular targets and/or drug-action mechanisms is significant in cancer treatment approaches; thus, FT-IR spectroscopy can be successfully applied as a novel drug-screening method in clinical research.
Cd133+/Cd44+prostate Cancer Stem Cells Exhibit Embryo-Like Behavior Patterns
(Elsevier Gmbh, 2021) Acikgoz, Eda; Soner, Burak Cem; Ozdil, Berrin; Guven, Mustafa
Cancer stem cells (CSCs), which act as an important bridge between cancer formation and embryonic development, represent a small population associated with tumor initiation, drug resistance, metastasis and recurrence. CSCs have the ability to form spheroids in three-dimensional culture systems. Tumor spheroids derived from CSCs with symmetric and asymmetric division patterns were found to contain highly heterogeneous cell groups. The biological behavior patterns which some CSCs display serve as an important bridge between cancer formation and embryonic development. The cell population in the DU-145 prostate cancer cell line with surface markers CD133+/CD44+ was isolated by FACS. Prostate spheroids were formed by using agarose-coated plates. The morphological characteristics of the cell population within spheroid structure and the expression of Ki-67 and Caspase-3 were investigated by histochemical methods. In this study, we observed that CD133+/CD44+ prostate CSCs form different spheroid structures as well as normal spheroid structures: i) some spheroid structures formed with a highly transparent zone on the outer part of the spheroid, in addition to the normal spheroidal zones and ii) spheroidal structures obtained from prostate CD1334+/CD44+ CSCs that share the same microenvironment are hollow spheres similar to the blastula-like structure in the embryo. These spheroidal structures exhibiting embryo-like properties indicate that the expression of embryonic factors might be reiterated in CSCs. Further investigation of the formation mechanism of the transparent zone and the hollow sphere will shed light on the embryonic origin of prostate cancer and the design of new therapeutic strategies.
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.
Design and Synthesis of Esipt-Based Imidazole Derivatives for Cell Imaging
(Amer Chemical Soc, 2024) Gul, Sergen; Acikgoz, Eda; Cakir, Mustafa; Menges, Nurettin
Excited-state intramolecular proton transfer (ESIPT)-based fluorescent molecules offer several exciting applications and are utilized most frequently as a cell imaging agent. Because of this, four distinct imidazole derivatives with ESIPT emission have been synthesized, and their fluorescence characteristics have been assessed in a variety of settings. Measurements using fluorescence spectroscopy have shown a promising candidate for cell staining, and potential candidate was specifically investigated for cell imaging uses in HT-29, MDA-MB-231, and HaCaT. Cytotoxicity of candidate molecule (1d) was analyzed using HT-29 and HaCaT cell lines, and at a dosage of 160 mu M, HT-29 and HaCaT cell lines showed no signs of important cell toxicity. When spectroscopically measured, compound 1d showed no fluorescence ability in phosphate-buffered saline (PBS) solution. However, after 8 h of incubation in several cell lines, excellent fluorescence characteristics were seen in the green and red filters.
Design, Synthesis, and Applications of Nucleic Acid-Specific Benzoxazole-N, N-Dialkylphenylamines Derivatives for Nucleolus Imaging in the Cells
(Elsevier, 2024) Kuzu, Burak; Acikgoz, Eda; Cakir, Mustafa
Considered the brain of the nucleus, alterations in the structure and function of the nucleolus are linked to numerous cellular functions and, consequently, contribute to several diseases. The identification of nucleolar morphology and activity via novel biomarkers presents new avenues for the development of therapeutic approaches for a variety of human diseases, including cancer, neurodegeneration, and aging. Therefore, specific detection of the nucleolus with fluorescence probes is of critical importance for clinical applications. In the present study, a series of benzoxazole- N,N -dialkylphenylamines derivative compounds were designed and synthesized based on the benzothiazole-based fluorescence probe Thioflavin T (ThT). Among the compounds, BX-3 and BX-16, which carry electron -withdrawing substituents in the benzoxazole ring, were observed to have higher fluorescence emission at wavelengths of 470 and 465 nM, respectively. The general morphology and divisions of the cells were examined under inverted and light microscopes, respectively, and the fluorescence potentials of selected compounds were determined using immunofluorescence microscopy. The fluorescence intensity of molecules and 3D interactive surface plot images of cells were analyzed using ImageJ software. Cell imaging analyses showed that BX-6 and BX-13, like ThT, specifically stain the cell nucleolus. Moreover, molecular docking studies showed that the compounds could identify the RNA -rich nucleolus by binding with high affinity to the guanine region in the RNA structure. The results suggest that the compounds may be an initial route in developing specific biosensor compounds for nucleolus imaging.
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.
Double Hit Strategy: Removal of Sialic Acid From the Dendritic Cell Surface and Loading With Cd44+/Cd24- Cell Lysate Inhibits Tumor Growth and Metastasis by Targeting Breast Cancer Stem Cells
(Elsevier, 2022) Acikgoz, Eda; Duzagac, Fahriye; Guven, Ummu; Yigitturk, Gurkan; Kose, Timur; Oktem, Gulperi
Cancer stem cells (CSCs), which represent the root cause of resistance to conventional treatments, recurrence, and metastasis, constitute the critical point of failure in cancer treatments. Targeting CSCs with dendritic cell (DC)-based vaccines have been an effective strategy, but sialic acids on the surface of DCs limit the interaction with loaded antigens. We hypothesized that removal of sialic acid moieties on immature DCs (iDCs) could significantly affect DC-CSC-antigen loading, thereby leading to DC maturation and improving immune recognition and activity. The lysate of CD44+/CD24-/low breast CSCs (BCSCs) was pulsed with sialidase-treated DCs to obtain mature dendritic cells (mDCs). The roles of cytoskeletal elements in antigen uptake and dendritic cell maturation were determined by immunofluorescence staining, flow cytometry, and cytokine measurement, respectively. To test the efficacy of the vaccine in vivo, CSCs tumor-bearing mice were immunized with iDC or mDC. Pulsing DCs with antigen increased the expression levels of actin, gelsolin, talin, WASp, and Arp2, especially in podosome-like regions. Compared with iDCs, mDCs expressed high levels of CD40, CD80, CD86 costimulatory molecules and increased IL-12 production. Vaccination with mDC: i) increased CD8+ and CD4 + T-cell numbers, ii) prevented tumor growth with anti-mitotic activity and apoptotic induction, iii) suppressed metastasis by decreasing Snail, Slug, and Twist expressions. This study reveals for the first time that sialic acid removal and loading with CSC antigens induces significant molecular, morphological, and functional changes in DCs and that this new DC identity may be considered for future combined immunotherapy strategies against breast tumors.
Doxorubicin-Induced Senescence Promotes Resistance To Cell Death by Modulating Genes Associated With Apoptotic and Necrotic Pathways in Prostate Cancer Du145 Cd133+/Cd44+cells
(Academic Press inc Elsevier Science, 2023) Tatar, Cansu; Avci, Cigir Biray; Acikgoz, Eda; Oktem, Gulperi
Cancer stem cells (CSCs) are the most important cause of cancer treatment failure. Traditional cancer treatments, such as chemotherapy and radiotherapy, damage healthy cells alongside malignant cells, leading to severe adverse effects. Therefore, inducing cellular senescence without triggering apoptosis, which further damages healthy cells, may be an alternative strategy. However, there is insufficient knowledge regarding senescence induction in CSCs that show resistance to treatment and stemness properties. The present study aims to elucidate the effects of senescence induction on proliferation, cell cycle, and apoptosis in prostate CSCs and non-CSCs. Prostate CSCs were isolated from DU145 cancer cells using the FACS method. Subsequently, senescence induction was performed in RWPE-1, DU145, prostate CSCs, and non-CSCs by using different concentrations of Doxorubicin (DOX). Cellular senescence was detected using the senescence markers SA-beta-gal, Ki67, and senescence-associated heterochromatin foci (SAHF). The effects of senescence on cell cycle and apoptosis were evaluated using the Muse Cell Analyzer, and genes in signaling pathways associated with the apoptotic/necrotic pathway were analyzed by real-time PCR. Prostate CSCs were isolated with 95.6 +/- 1.4% purity according to CD133+/CD44+ characteristics, and spheroid formation belonging to stem cells was observed. After DOXinduced senescence, we observed morphological changes, SA-beta-gal positivity, SAHF, and the lack of Ki67 in senescent cells. Furthermore; we detected G2/M cell cycle arrest and downregulation of various apoptosis-related genes in senescent prostate CSCs. Our results showed that DOX is a potent inducer of senescence for prostate CSCs, inhibits proliferation by arresting the cell cycle, and senescent prostate CSCs develop resistance to apoptosis.
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.
Effect of Flavopiridol on Cell Cycle, Apoptosis and Biomolecule Structure Changes in Breast Cancer Stem Cells
(Galenos Publ House, 2020) Acikgoz, Eda; Guler, Gunnur; Oktem, Gulperi
Objective: Cancer stem cells (CSCs) are a small population in cancer, which are responsible for therapeutic resistance, relapse and metastasis. Flavopiridol has antitumor activity against various types of cancer cells. The mechanism of action of flavopiridol on CD44+/CD24- breast CSCs has not yet been fully elucidated. The aim of this study was to evaluate the mechanism of action of flavopiridol on breast CSCs (BCSC) in terms of apoptosis, cell cycle and biomolecular changes. Methods: In human breast cancer, cells with CD44+/CD24-markers were isolated from MCF-7 cell line using flow cytometry. The induction of apoptosis was investigated by Annexin-V. The effect of flavopiridol on cell cycle arrest was determined and the percent of cell populations at G0/G1, S and G2/M cycles were identified. The effect of the drug on three-dimensional cell cultures was investigated using a multicellular tumor spheroid model. In addition, the effect of flavopiridol on biomolecules has been evaluated using Fourier transform infrared (FTIR) spectroscopy, which has recently been used effectively in various scientific fields. Results: Flavopiridol especially induced early apoptosis. Cell cycle analyses revealed that flavopiridol induced cell cycle arrest in G0/G1 phase. Decreased number and diameter of spheroids was observed following flavopiridol treatment. ATR-FTIR data showed that treatment with flavopiridol led to significant changes in nucleic acids. Conclusion: According to the data obtained in this study, flavopiridol exhibits anticancer effects by altering the structure/expression level of nucleic acids and changing cell cycle progression and inducing apoptosis. These finding reveals that flavopiridol can be an effective antitumor agent for the treatment of breast cancer after in vivo and phase studies are completed.
Effects of Exogenous Ghrelin Treatment on Oxidative Stress, Inflammation and Histological Parameters in a Fat-Fed Streptozotocin Rat Model
(Taylor & Francis Ltd, 2025) Ergul Erkec, Ozlem; Huyut, Zubeyir; Acikgoz, Eda; Huyut, Mehmet Tahir
In this study, the anti-inflammatory, antioxidative, and protective effects of ghrelin were investigated in a fat-fed streptozotocin (STZ) rat model and compared with metformin, diabetes and the healthy control groups. Histopathological evaluations were performed on H&E-stained pancreas and brain sections. Biochemical parameters were investigated by enzyme-linked immunosorbent assay. Blood glucose levels were significantly decreased with ghrelin or metformin treatments than the diabetes group. STZ administration increased brain, renal and pancreatic IL-1 beta, TNF-alpha and MDA while decreasing GPX, CAT, SOD, and NGF levels. Ghrelin increased renal GPX, CAT, NGF pancreatic GPX, SOD, CAT, NGF and brain SOD, NGF while it decreased renal, pancreatic and brain IL-1 beta, TNF-alpha and MDA levels. Ghrelin reduced neuronal loss and degeneration in the cerebral cortex and hippocampus and greatly ameliorated diabetes-related damage in pancreas. In conclusion, the data suggested that ghrelin is an effective candidate as a protectant for reducing the adverse effects of diabetes.
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.
Embryonic Microenvironment Suppresses Yy1 and Yy1-Related Genes in Prostate Cancer Stem Cells
(Elsevier Gmbh, 2024) Taskiran, Aysegul; Oktem, Gulperi; Demir, Aleyna; Oltulu, Fatih; Ozcinar, Emine; Duzagac, Fahriye; Acikgoz, Eda
Yin yang 1 (YY1), a transcription factor, plays crucial roles in cell fate specification, differentiation, and pluripotency during embryonic development. It is also involved in tumorigenesis, drug resistance, metastasis, and relapse caused by cancer stem cells (CSCs), particularly in prostate cancer (PCa). Targeting YY1 could potentially eliminate prostate CSCs (PCSCs) and provide novel therapeutic approaches. PCa tissues often exhibit elevated YY1 expression levels, especially in high-grade cases. Notably, high-grade PCa tissues from 58 PCa patients and CD133high/CD44high high /CD44 high PCSCs isolated from DU145 PCa cell line by FACS both showed significantly increased YY1 expression as observed through immunofluorescence staining, respectively. To investigate the embryonic microenvironment impact on YY1 expression in CSC populations, firstly PCSCs were microinjected into the inner cell mass of blastocysts and then PCSCs were co-cultured with blastocysts. Next Generation Sequencing was used to analyze alterations in YY1 and related gene expressions. Interestingly, exposure to the embryonic microenvironment significantly reduced the expressions of YY1, YY2, and other relevant genes in PCSCs. These findings emphasize the tumor-suppressing effects of the embryonic environment by downregulating YY1 and YY1-related genes in PCSCs, thus providing promising strategies for PCa therapy. Through elucidating the mechanisms involved in embryonic reprogramming and its effects on YY1 expression, this research offers opportunities for further investigation into focused therapies directed against PCSCs, therefore enhancing the outcomes of PCa therapy. As a result, PCa tumors may benefit from YY1 and associated genes as a novel therapeutic target.
Enhanced G2/M Arrest, Caspase Related Apoptosis and Reduced E-Cadherin Dependent Intercellular Adhesion by Trabectedin in Prostate Cancer Stem Cells
(Public Library Science, 2015) Acikgoz, Eda; Guven, Ummu; Duzagac, Fahriye; Uslu, Ruchan; Kara, Mikail; Soner, Burak Cem; Oktem, Gulperi
Trabectedin (Yondelis, ET-743) is a marine-derived tetrahydroisoquinoline alkaloid. It is originally derived from the Caribbean marine tunicate Ecteinascidia turbinata and currently produced synthetically. Trabectedin is active against a variety of tumor cell lines growing in culture. The present study focused on the effect of trabectedin in cell proliferation, cell cycle progression, apoptosis and spheroid formation in prostate cancer stem cells (CSCs). Cluster of differentiation (CD) 133(+high)/CD44(+high) prostate CSCs were isolated from the DU145 and PC-3 human prostate cancer cell line through flow cytometry. We studied the growth-inhibitory effects of trabectedin and its molecular mechanisms on human prostate CSCs and non-CSCs. DU-145 and PC-3 CSCs were treated with 0.1, 1, 10 and 100 nM trabectedin for 24, 48 and 72 h and the growth inhibition rates were examined using the sphere-forming assay. Annexin-V assay and immunofluorescence analyses were performed for the detection of the cell death. Concentration-dependent effects of trabectedin on the cell cycle were also evaluated. The cells were exposed to the different doses of trabectedin for 24, 48 and 72 h to evaluate the effect of trabectedin on the number and diameter of spheroids. According to the results, trabectedin induced cytotoxicity and apoptosis at the IC50 dose, resulting in a significant increase expression of caspase-3, caspase-8, caspase-9, p53 and decrease expression of bcl-2 in dose-dependentmanner. Cell cycle analyses revealed that trabectedin induces dose-dependent G2/M-phase cell cycle arrest, particularly at high-dose treatments. Three-dimensional culture studies showed that trabectedin reduced the number and diameter of spheroids of DU145 and PC3 CSCs. Furthermore, we have found that trabectedin disrupted cell-cell interactions via E-cadherin in prostasphere of DU-145 and PC-3 CSCs. Our results showed that trabectedin inhibits cellular proliferation and accelerates apoptotic events in prostate CSCs; and may be a potential effective therapeutic agent against prostate cancer.
Expression of the Low-Density Lipoprotein Receptor (Ldlr) Gene Family in Cd133+/Cd44+ Prostate Cancer Stem Cells
(Dokuz Eylul Univ inst Health Sciences, 2023) Soner, Burak Cem; Acikgoz, Eda; Duzagac, Fahriye; Parlayan, Cuneyd
Purpose: The low-density lipoprotein receptor gene (LDLR) family plays a fundamental role in many malignancies and may have a putative cancer-boosting function. In our study, we have attempted to comparatively investigate the differential gene expressions of LDLR family in a normal prostate epithelial cell line (RWPE-1), prostate cancer cell line (DU145 cell line), prostate cancer stem cells (DU145 CSCs), and non-CSCs (DU145 non-CSCs, bulk population). Material and Methods: Cancer stem cells in the DU-145 prostate cancer cell line were isolated by flow cytometry according to CD133 and CD44 cell surface properties. Whole transcriptome sequencing data was comprehensively analyzed for each group. The protein-protein interaction network was determined using the STRING protein database. Results: Our data showed that the expression levels of Low-density lipoprotein receptor-related proteins (LRPs) such as LRP1, LRP3, LRP8 and, LRP11 were increased in the DU145 CSCs relative to the normal prostate epithelial cell line. Conclusion: Overall, our data suggest that the LRP functions and/or the expression in prostate cancer may ultimately change the invasive phenotype of the CSCs.