Molecular Biology and Genetics / Moleküler Biyoloji ve Genetik

Permanent URI for this collectionhttps://hdl.handle.net/11147/9

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Author: search.filters.author.Saydam, GürayWoS Q: search.filters.wosQuartile.Q3

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  • Article
    Citation - WoS: 36
    Citation - Scopus: 42
    Resveratrol Triggers Apoptosis Through Regulating Ceramide Metabolizing Genes in Human K562 Chronic Myeloid Leukemia Cells
    (Routledge, 2011) Kartal Yandım, Melis; Saydam, Güray; Şahin, Fahri; Baran, Yusuf
    Resveratrol, an important phytoalexin in many plants, has been reported to have cytotoxic effects on various types of cancer. Ceramide is a bioactive sphingolipid that regulates many signaling pathways, including cell growth and proliferation, senescence and quiescence, apoptosis, and cell cycle. Ceramides are generated by longevity assurance genes (LASS). Glucosylceramide synthase (GCS) and sphingosine kinase-1 (SK-1) enzymes can convert ceramides to antiapoptotic molecules, glucosylceramide, and sphingosine-1-phosphate, respectively. C8:ceramide, an important cell-permeable analogue of natural ceramides, increases intracellular ceramide levels significantly, while 1-phenyl-2-decanoylamino-3-morpholino-1-propanol (PDMP) and SK-1 inhibitor increase accumulation of ceramides by inhibiting GCS and SK-1, respectively. Chronic myelogenous leukemia (CML) is a hematological disorder resulting from generation of BCR/ABL oncogene. In this study, we examined the roles of ceramide metabolizing genes in resveratrol-induced apoptosis in K562 CML cells. There were synergistic cytotoxic and apoptotic effects of resveratrol with coadministration of C8:ceramide, PDMP, and SK-1 inhibitor. Interestingly, there were also significant increases in expression levels of LASS genes and decreases in expression levels of GCS and SK-1 in K562 cells in response to resveratrol. Our data, in total, showed for the first time that resveratrol might kill CML cells through increasing intracellular generation and accumulation of apoptotic ceramides. Copyright © 2011, Taylor & Francis Group, LLC.
  • Article
    Citation - WoS: 31
    Citation - Scopus: 36
    Quercetin-Induced Apoptosis Involves Increased Htert Enzyme Activity of Leukemic Cells
    (Taylor and Francis Ltd., 2011) Avcı, Çığır Biray; Yılmaz, Sunde; Doğan, Zeynep Özlem; Saydam, Güray; Dodurga, Yavuz; Ekiz, Hüseyin Atakan; Kartal, Melis; Şahin, Fahri; Baran, Yusuf; Gündüz, Cumhur
    We aimed to examine the growth suppressive effects of quercetin on acute promyelocytic and lymphoblastic leukemia and chronic myeloid leukemia, and to find out whether the growth suppression is related to the blocking of telomerase enzyme activity. Cytotoxic effects of quercetin were shown by trypan blue analyses. Apoptotic effects of quercetin were examined by acridine orange and ethidium bromide staining by fluorescence microscopy. The effects of quercetin on telomerase enzyme activity were shown by hTERT Quantification Kit. Our results demonstrated that quercetin has antiproliferative and apoptotic effects on T-cell acute lymphoblastic leukemia (ALL), acute promyelocytic leukemia, and chronic myeloid leukemia (CML) cells. We also showed for the first time by this study that quercetin suppresses the activity of telomerase in ALL and CML cells. The results of this study show the importance of quercetin for its therapeutic potential in treatment of leukemias.