Browsing by Author "Kurt, FO"

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    Effects of caffeic acid phenethyl ester on matrix molecules and angiogenetic and anti-angiogenetic factors in gastric cancer cells cultured on different substrates
    Kosova, F; Kurt, FO; Olmez, E; Tuglu, I; Ari, Z
    Migration, invasion, metastasis and angiogenesis associated with cancer depend on the surrounding microenvironment. Angiogenesis, the growth of new capillaries, is a regulator of cancer growth and a useful target for cancer therapy. We examined matrix protein interactions in a gastric cancer cell culture that was treated with different doses of caffeic acid (3,4-dihydroxycinnamic acid) phenethyl ester (CAPE). We also investigated the relations among the levels of vascular endothelial growth factor (VEGF), matrix metalloproteinase-9 (MMP-9), endostatin (ES) and trombospondin-1 (TSP-1). Cytotoxity of CAPE was measured using the 3-(4,5-dmethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. We examined the behavior of cells on laminin and collagen I coated surfaces in response to the angiogenic effect of these matrix molecules. We examined the protein alterations of these matrix molecules immunohistochemically and measured the levels of VEGF, MMP-9, ES and TSP-1 using the ELISA test. We showed that application of CAPE to the gastric cancer cell line on tissue culture plastic, laminin and collagen I significantly decreased the VEGF and MMP-9 protein levels. We found that TSP-1 levels were increased significantly in the gastric cancer cells after application of CAPE. The protein levels of gastric cancer cells also were increased significantly when tissue was cultured on laminin and collagen I. Application of CAPE to cells on laminin or collagen I coated surfaces significantly increased all of the proteins except ES. ES levels were increased on the collagen I covered surfaces, but the laminin surface decreased the levels of ES significantly. We demonstrated the beneficial effect of CAPE on a gastric cancer cell line including inhibition of proliferation and induction of some proteins that might be related to decreased angiogenesis.
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    Apoptosis of colon cancer cells under the effect of geldanamycin derivate
    Kosova, F; Kasar, Z; Tuglu, I; Kurt, FO; Gok, S; Ari, Z; Imren, T
    AIM: The apoptotic effect of geldanamycin derivative may be important for the colorectal cancer therapy. The mechanisms of apoptosis require understanding of the behavior of colon cancer cell line Colo-205 which mimics colon adenocarcinoma. Therefore, the effect of IC50 dose of 17-allylamino-17-demethoxygeldanamycin (17-AAG) on the colon cancer cells in vitro was studied for its anti-apoptotic activity. METHOD: Apoptotic ratio of the Colo-205 cells was determined after 17-AAG application with terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining and apoptosis related genes. Apoptosis signal path related key mitochondria! proteins, cytochrome c, bcl-2, caspase 9 and Apaf-1 expression were examined with RT-PCR method. RESULTS: 17-AAG caused induction of cell death. Apoptotic related genes such as cytochrome-c, Apaf-1 and caspase-9 protein expressions were increased significantly (p < 0.05) and anti-apoptotic bcl-2 expression was decreased significantly (p < 0.05). Our results indicated that the application of 17-AAG on Colo-205 cells showed anticancer effect by the apoptosis due to alteration of apoptotic genes. CONCLUSION: The apoptotic effect of 17-AAG as an natural product for alternative medicine would be very important for the success and quality of life during the treatment of colon carcinoma with the combination of anticancer drugs (Tab. 1, Fig. 2, Ref. 32). Text in PDF www.elis.sk.
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    Effect of geldanamycin on the expression of the matrix molecules and angiogenetic factors in a gastric cancer cell line
    Gürpinar, T; Kosova, F; Kurt, FO; Cambaz, SU; Yücel, AT; Umur, N; Tuglu, MI
    Angiogenesis is the formation of new blood vessels. Angiogenesis affects cancer growth and is a useful target for cancer therapeutics. The effects of geldanamycin on angiogenesis in cases of gastric cancer are poorly understood. We investigated the effects of different doses of 17-allylamino-17-demethoxygeldanamycin (17-AGG), a semi-synthetic derivative of geldanamycin, on the interactions between cellular matrix proteins and angiogenesis factors in a gastric cancer cell line. We examined cancer cells on laminin and collagen I coated surfaces to determine their response to the angiogenic effect of these matrix molecules. We also evaluated the expression levels of VEGF, MMP-9, ES and TSP-1 using ELISA. We found that application of 17-AAG to the gastric cancer cell line on culture dish plastic decreased VEGF, TSP-1, ES and MMP-9 expression, whereas of all of these proteins were increased by laminin and collagen coating. 17-AAG currently is in clinical trial phase 2 and may be a promising drug for treatment of gastric cancer.
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    Potential Clinical Use of Differentiated Cells From Embryonic or Mesencyhmal Stem Cells in Orthopaedic Problems
    Kurt, FO; Vatansever, HS
    Stem cells are classified by their tissue source. Embryonic stem cells that are derived from the inner cell mass of blastocyst stage embryos are highly proliferative in their undifferentiated state. A multipotent type of mesenchymal stem cells is isolated from various types of tissues such as bone marrow, fat tissue etc. The dynamics of embryonic and adult stem cell cycles are profoundly dissimilar from the culture of stem cells. After improving the culture conditions and differentiation potentials, differentiated stem cells are the first cells to be preferred in modern regenerative medicine and tissue engineering. This review article focuses on the cell-based therapy of orthopedic problems. We explore the challenges associated with bone repair and regeneration using embryonic or mesenchymal stem cells that are in undifferentiated or/and differentiated condition. This paper also discusses optimizing the best cell type, differentiation condition and using them on bone tissue engineering for future investigations.
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    Cell cycle controlling of cancer stem cells in primary and metastatic colon carcinoma
    Kurt, FO; Kendirci, R; Türkoglu, C; Vatansever, S
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    The Effect of Boric Acid and Calcium Fructoborate on T Helper Cell Differentiation by Influencing Foxp3 and Ror-γt in Rheumatoid Arthritis and Systemic Lupus Erythematosus
    Yapar, R; Gündüz, ÖS; Kurt, FO; Korkmaz, M
    Many animal and human studies indicate that boric acid and calcium fructoborate have effects on helper T cells in immunity. The aim of our study is to evaluate the effects of boric acid and calcium fructoborate on Treg (CD4+Foxp3+) and Th17 (CD4+Ror-gamma t+) cell populations and related cytokine levels in mononuclear cells isolated from peripheral blood samples of rheumatoid arthritis and systemic lupus erythematosus patients. Newly diagnosed rheumatoid arthritis (n = 10) patients, systemic lupus erythematosus (n = 5) patients, and healthy individuals (n = 9) were included in this study. Consent forms were obtained from all individuals participating the study, blood samples were taken, and peripheral blood mononuclear cells were isolated. Isolated cells were exposed to low-dose and high-dose boric acid and calcium fructoborate in cell culture. Treg and Th17 cell populations were analyzed by flow cytometry after 48 h of exposure. IL-2, IL-6, IL-17, IL-23, TNF-alpha, and TGF-beta levels in the culture medium were tested by ELISA method. At the end of the study, in healthy controls, high-dose BA improved the Treg/Th17 population but could not display similar effects on RA and SLE group. However, both boric acid and calcium fructoborate at different doses showed an increasing effect on Ror-gamma t in RA and SLE group. Different doses of BA and CaF treatment found to have a variable effect on cytokine. Both BA and CaF in low doses decreased TNF-alpha levels in RA group which shows that these boron compounds could contribute positively to the treatment of autoimmune diseases.
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    Synthesis and cytotoxic activities of organometallic Ru(II) diamine complexes
    Kavukcu, SB; Sahin, O; Vatansever, HS; Kurt, FO; Korkmaz, M; Kendirci, R; Pelit, L; Türkmen, H
    A series of mono and bimetallic ruthenium(II) arene complexes bearing diamine (Ru1-6) were prepared and fully characterized by H-1, C-13, F-19, and P-31 NMR spectroscopy and elemental analysis. The crystal structure of the bimetallic complex (Ru-5) was determined by X-ray crystallography. Monometallic analogues (Ru1-3) were synthesized to investigate the contributions of ruthenium and the other organic groups (aren, ethylenediamine, butyl) to the activity. The electrochemical behaviors of mono and bimetallic complexes were obtained from the relationship between cyclic voltammetry (CV) and the biological activities of the compounds. The cytotoxic activities of the complexes (Ru1-6) were tested against wide-scale cancer cell lines, namely HeLa, MDA-MB-231, DU-145, LNCaP, Hep-G2, Saos-2, PC-3, and MCF-7, and normal cell lines 3T3-L1 and Vero. Diamine Ru(II) arene complexes have unique biological characteristics and they are promising models for new anticancer drug development. MTT analysis reveals that each synthesized Ru complex showed cytotoxic activity towards the different cancer cells. In particular, three Ru complexes (Ru-3, Ru-5 and Ru-6) showed less toxic effects on the cancer cells than the others. These novel Ru complexes affected both cancer and normal cell lines. As they had a toxic effect on the cells, the dosage applied should be tested before being used for in vivo applications. Cytotoxicity tests have shown that the bimetallic complex Ru-6 was effective on all cancer cells. The effect of bimetallic enhancement on cancer cell lines, the systematic variation of the intermetallic distance and the ligand donor properties of the mono and bimetallic complexes were explored based on the cytotoxic activity. The interaction with FS-DNA and the stability/aquation of the complexes (Ru-3 and Ru-6) were investigated with H-1 NMR spectroscopy. The binding modes between the complexes (Ru-3 and Ru-6) and DNA were investigated via UV-Vis spectroscopy.
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    Inhibitory Effects of Propolis on Human Osteogenic Sarcoma Cell Proliferation Mediated by Caspase Patway
    Kurt, FO; Vatansever, HS; Sorkun, K; Gurhan, SID; Turkoz, E; Gencay, O; Salih, B
    A natural product Propolis, is a resinous material gathered by honeybees from the buds and bark of certain trees and plants. Propolis contains various chemical components of biological activities, including antimutagenic, antioxidant, antibacterial, antiviral and anticarsinogenic. Therefore, the aim of this study is to investigate the antiapoptotic effect of propolis extracts (PE) using caspase pathway in the human osteogenic sarcoma cell line SAOS-2 in culture. The extracts which produced in ecologic environment were taken from the Hacettepe University, Beytepe Campus area-Ankara were used. Seven different PE at 0.5, 0.25, 0.125 and 0.063 mg/ml were added to SAOS-2 cell line for two days incubation. For cell proliferation and cytotoxicty analyses MTT, for apoptotic cell death determination TUNEL method, for distribution of caspase 6, caspase 8 and caspase 9 indirect immunocytochemistry analyses were used. After MTT analyses, the most effect was observed PE 7 at the 0.125 mg/ml dilution. The number of TUNEL positive cells was more detectable at PE 4 and 5 at the 0.063 mg/ml, and PE 7 at the 0.125 mg/ml dilutions. The immunoreactivity of caspase 6 was stronger than caspase 8 and 9. Moreover, density of caspase 6 staining was much better especially in PE 7 at the 0.125 mg/ml dilution. In conclusion, the mechanisms of apoptosis induction by PE may appear via caspase pathway because of its anticanserogenic effect. PE may be usefull in the cancer treatment protocol.