Molecular Biology and Genetics / Moleküler Biyoloji ve Genetik

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

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  • Article
    Citation - WoS: 24
    Citation - Scopus: 24
    Mechanisms Responsible for Nilotinib Resistance in Human Chronic Myeloid Leukemia Cells and Reversal of Resistance
    (Informa Healthcare, 2013) Camgöz, Aylin; Gençer, Emel Başak; Ural, Ali Uğur; Baran, Yusuf
    Multidrug resistance remains a significant obstacle to successful chemotherapy. The ability to determine the possible resistance mechanisms and surmount the resistance is likely to improve chemotherapy. Nilotinib is a very effective drug in the treatment of imatinib-sensitive or -resistant patients. Although very successful hematologic and cytogenetic responses have been obtained in nilotinib-treated patients, in recent years cases showing resistance to nilotinib have been observed. We aimed to examine the mechanisms underlying nilotinib resistance and to provide new targets for the treatment of chronic myeloid leukemia (CML). There was an up-regulation of antiapoptotic BCR/ABL, GCS and SK-1 genes and MRP1 transporter gene and down-regulation of apoptotic Bax and CerS1 genes in nilotinib-resistant cells. There was no mutation in the nilotinib-binding region of BCR/ABL in resistant cells. Inhibiton of GCS and SK-1 restored nilotinib sensitivity. Targeting the proteins that are involved in nilotinib resistance in addition to the inhibition of BCR/ABL could be a better method of treatment in CML.
  • Article
    Citation - WoS: 16
    Citation - Scopus: 18
    Roles of Ceramide Synthase and Ceramide Clearence Genes in Nilotinib-Induced Cell Death in Chronic Myeloidleukemia Cells
    (Informa Healthcare, 2011) Camgöz, Aylin; Gençer, Emel Başak; Ural, Ali Uğur; Avcu, Ferit; Baran, Yusuf
    In this study, we aimed to increase the sensitivity of human K562 and Meg-01 chronic myeloid leukemia (CML) cells to nilotinib by targeting bioactive sphingolipids, in addition to investigating the roles of ceramide metabolizing genes in nilotinib induced apoptosis. Cytotoxic effects of nilotinib, C8:ceramide, glucosyle ceramide synthase (GCS) and sphingosine kinase-1 (SK-1) inhibitors were determined by XTT cell proliferation assay and synergism between the agents was determined by isobologram analysis. Also, quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) results demonstrated that expression levels of longevity assurance (LASS) genes in response to nilotinib were correlated with sensitivity to nilotinib. For the first time, The results of this study showed for the first time that nilotinib induces apoptosis through upregulating ceramide synthase genes and downregulating SK-1 in CML cells in addition to inhibition of BCR/ABL. On the other hand, manipulating bioactive sphingolipids toward generation/accumulation of ceramides increased the apoptotic effects of nilotinib in CML cells.