WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7150

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Now showing 1 - 10 of 139
  • Article
    Citation - WoS: 139
    Granulocytic Sarcoma: a Systematic Review
    (e-Century Publishing Corporation, 2013) Yılmaz, Asu Fergün; Saydam, Güray; Şahin, Fahri; Baran, Yusuf
    Granulocytic sarcoma also called myeloid sarcoma is an extramedullary tumor of immature granulocytic cells. It is a rare entity, and mostly accompanied by acute myeloid leukemia. It is observed during the course of myeloproliferative disorders especially in chronic myeloid leukemia and myelodysplastic syndromes. In some rare circumstances, it is detected before clinical signs of leukemia or other diseases. When the bone marrow biopsy reveals no other hematologic malignancies, the granulocytic sarcoma is described as nonleukemic, primary or isolated. It is observed at any part of the body but the most common locations are soft tissues, bone, peritoneum and lymph nodes. Presenting signs or symptoms are mainly due to mass effect of the tumor and dysfunction of the organ, or the tissue that is affected. The diagnosis is performed by biopsy of the tumor. The tumor consists of immature granulocytic cells, which could be documented by H&E, immunohistochemistry, and flow cytometric methods. Fluorescence in-situ hybridization and molecular analysis are also performed. The optimal time and type of treatment is not clear. Surgery could be an option especially for tumors, which cause organ dysfunction and/or obstruction. Systemic treatment should be considered in all patients because without systemic treatment, relapses and progression to acute myeloid leukemia is the ultimate fate of the disease in many cases. Cytarabine-containing remission-induction chemotherapies have been the most applied therapeutic strategies, but it is not clear whether the consolidation therapies are required or not, and what kind of regimens are appropriate. The role of hematopoietic stem cell transplantation (HSC) as a consolidation regimen is not clear, but, after the relapse of the disease with or without bone marrow involvement, HSC transplantation should be considered in suitable patients after the reinduction performed by AML chemotherapies. There is only limited data about the role of radiotherapy in these patients. It could be used in patients with relapsed disease, organ dysfunction which should be quickly relieved and inadequate response to chemotherapy. The effect of radiotherapy on overall survival is not known. New prospective studies and clinical trials are needed to generate guidelines for the treatment of primary granulocytic sarcomas.
  • Article
    Citation - WoS: 15
    Changes in Molecular Biology of Chronic Myeloid Leukemia in Tyrosine Kinase Inhibitor Era
    (e-Century Publishing Corporation, 2013) Cömert, Melda; Baran, Yusuf; Saydam, Güray
    Chronic myeloid leukemia (CML) is a clonal myeloproliferative disease characterized by a reciprocal translocation between long arms of chromosomes 9 and 22 t(9; 22) that generates the BCR-ABL fusion gene. If left untreated, newly diagnosed chronic phase CML patients finally progress to accelerated and blastic phase. After the introduction of tyrosine kinase inhibitors (TKIs), treatment strategies of CML changed dramatically. However, the development of resistance to TKIs started to create problems over time. In this review, the current information about CML biology before and after imatinib mesylate treatment is summarized.
  • Article
    Citation - WoS: 16
    Cumulative Clinical Experience From a Decade of Use: Imatinib as First-Line Treatment of Chronic Myeloid Leukemia
    (Dove Medical Press Ltd., 2012) Baran, Yusuf; Saydam, Güray
    Chronic myeloid leukemia (CML) is a malignant disease that originates in the bone marrow and is designated by the presence of the Philadelphia (Ph+) chromosome, a translocation between chromosomes 9 and 22. Targeted therapy against CML commenced with the development of small-molecule tyrosine kinase inhibitors (TKIs) exerting their effect against the oncogenic breakpoint cluster region (BCR)-ABL fusion protein. Imatinib emerged as the first successful example of a TKI used for the treatment of chronic-phase CML patients and resulted in significant improvements in response rate and overall survival compared with previous treatments. However, a significant portion of patients failed to respond to the therapy and developed resistance against imatinib. Second-generation TKIs nilotinib and dasatinib were to have higher efficiency in clinical trials in imatinib- resistant or intolerant CML patients com pared with imatinib. Identification of novel strategies such as dose escalation, drug combination therapy, and use of novel BCR-ABL inhibitors may eventually overcome resistance against BCR-ABL TKIs. This article reviews the history of CML, including the treatment strategies used prediscovery of TKIs and the preclinical and clinical data obtained after the use of imatinib, and the second-generation TKIs developed for the treatment of CML.
  • Article
    Citation - WoS: 37
    Mechanisms of Cellular Resistance To Imatinib in Human Chronic Myeloid Leukemia Cells
    (Taylor and Francis Ltd., 2007) Baran, Yusuf; Ural, Ali Uğur; Gündüz, Ufuk
    A major advancement in the treatment of chronic myeloid leukemia (CML) has been the development of imatinib, which has shown striking activity in the chronic phase and the accelerated phase, but less so in the blast phase of the disease. Despite high rates of hematologic and cytogenetic responses to therapy, the emergence of resistance to imatinib has been recognized as a major problem in the treatment of patients with CML. Various cellular mechanisms may be involved in the nature of cellular resistance. Increased amount of target, alteration in structure of target proteins, decreased drug uptake and increased detoxification are well-known mechanisms of resistance. On the other hand, in some cases, even if anticancer drugs reach their sites of action, bypassing drug efflux system of the cells, some cells still may survive via the dysregulation of apoptotic signalling. In this study, mechanisms of resistance to imatinib-induced apoptosis in human Meg-01 CML cells were examined. Continuous exposure of cells to step-wise increasing concentrations of imatinib resulted in the selection of 200- and 1000 nM imatinib-resistant sub-lines referred to as Meg-01/IMA-0,2 and Meg-01/1MA-1, respectively. MTT cell proliferation, cell cycle analyses and trypan blue dye exclusion analyses showed that Meg-0l/IMA-1 cells were resistant to imatinib-induced apoptosis as compared to parental sensitive cells. There was an increased expression of BCR/ABL, Bcl-2 and an increase in mitochondrial membrane potential (MMP) detected in resistant cells comparing to parental sensitive cells. There was no mutation detected in imatinib binding site of ABL kinase region. Various diverse mechanisms have been reported for their involvement in the multidrug resistance. In this study, it has been shown that the degree of BCR/ABL expression appears to be directly proportional to the levels of imatinib resistance. In addition, there have been BCR/ABL-independent mechanisms reported for deriving resistance against imatinib. Our results revealed that besides BCR/ABL overexpression, imatinib resistance also depends on the inhibition of apoptosis as a result of up-regulation of anti-apoptotic stimuli and down-regulation of pro-apoptotic stimuli through MMP but does not depend on any mutation on imatinib binding site of ABL kinase.
  • Conference Object
    Cytotoxic Effects of Apigenin on Multiple Myeloma Cells
    (Ferrata Storti Foundation, 2013) Baran, Yusuf; Yılmaz, S.; Cincin, Zeynep; Kozanoğlu, İlknur; Çakmakoğlu, Bedia; Özdoğu, Hakan
    [No abstract available]
  • Conference Object
    Changes in Gene Expression Profiles in Response To Apigenin in Imatinib Sensitive and Resistant Chronic Myeloid Leukemia Cells
    (FERRATA STORTI FOUNDATION, 2013) Baran, Yusuf; Gökbulut, Aysun; Cincin, Zeynep; Çakmakoğlu, Bedia; Kozanoğlu, İlknur
    [No abstract available]
  • Conference Object
    Determination of Cytotoxic and Apoptotic Effects of Caffeic Acid Phenethyl Ester and Gossypol in Combination With Fludarabine at a Molecular Level in Acute Lymphoblastic Leukemia Cells
    (Ferrata Storti Foundation, 2013) Baran, Yusuf; İskender, G.; Pişkin, Özden; Özcan, Mehmet Ali
    [No abstract available]
  • Conference Object
    Diagnostic and Therapeutic Potentials of Expression Levels of Bioactive Sphingolipid Genes in Newly Diagnosed and Drug-Resistant Chronic Myeloid Leukemia Patients
    (Ferrata Storti Foundation, 2013) Baran, Yusuf; Yandım, Melis; Kozanoğlu, İlknur; Özdoğu, Hakan; Pişkin, Özden; Özcan, Mehmet Ali
    [No abstract available]
  • Conference Object
    Immunologically Detection of Bcr/Abl Fusion Protein With Flow Cytometry in K562 Chronic Myeloid Leukemia Cells and Comparison With Rt-Pcr Results
    (Ferrata Storti Foundation, 2013) Kozanoğlu, İlknur; Aygün, B.; Boğa, I.; Cansun, C.; Üstündağ, N.; Baran, Yusuf; Özdoğu, Hakan
    [No abstract available]
  • Conference Object
    Comparison of Ishage-Based Cd34 (+) Cell Enumeration Protocols on Bd Facs Canto Iı and Attune Flow Cytometers
    (Nature Publishing Group, 2014) Kozanoğlu, İlknur; Ünver, Gülşah; Sarıtürk, Çağla; Baran, Yusuf; Yeral, Mahmut; Boğa, Can; Özdoğu, Hakan
    [No abstract available]