PubMed İndeksli Yayınlar Koleksiyonu / PubMed Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7645

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  • Article
    Citation - WoS: 4
    Citation - Scopus: 5
    Cytotoxic and Apoptotic Effects of 1,2-Diborolanes With Strong Donor Substitutes on Human Cancer Cells
    (Elsevier, 2021) Şahin, Yüksel; Aslantürk, Özlem Sultan; Çelik, Tülay; Sevinçek, Resul; Aygün, Muhittin; Metin, Kubilay; Fırıncı, Erkan; Özgener, Hüseyin
    In recent years, boron compounds have become more common as chemotherapy agents against certain types of cancers. Along with the development of boron-based therapeutic agents have come investigations into the various cancers and biochemical and molecular mechanisms affected by boron compounds and the relationships between boron compounds and chemical protection against cancer. In this preliminary study, the effects of new 1,2-N-substituted-1,2-diborolane derivatives on types of breast and liver cancers were examined for the first time. Four were found to significantly affect the cell viabilities and mitochondrial membrane potential changes in MCF-7, HepG2 and Hep3B cancer cells. Each was prepared in n-hexane at various concentrations (5, 10, 25, 50, 75 and 100 µg/mL). Human peripheral blood lymphocytes were used as control cells. Compounds 1, 2, 3a, and 3b 1,2-diborolane derivatives selectively killed cancer cells, but compound 1 was cytotoxic in a concentration-dependent manner on HepG2 and Hep3B and only at concentrations of at least 75 µg/mL on MCF-7 cells. Compound 3a exhibited cytotoxic effect on lymphocytes at 75 and 100 µgmL-1 concentrations, but compounds 1, 2 and 3b, 3c and 3d have not possessed significant cytotoxic effect on lymphocytes. Compounds 3c and 3d have not possessed significant cytotoxic effects. Mitochondrial membrane potential assay results supported these findings. Our results reveal that 1,2-diborolane derivates have high cytotoxic and apoptotic activities on human hepatocarcinoma cells and are therefore potential candidates in the development of new drugs against liver cancer.
  • Article
    Citation - WoS: 278
    Citation - Scopus: 295
    Molecular Mechanisms of Drug Resistance and Its Reversal in Cancer
    (Taylor and Francis Ltd., 2016) Kartal Yandım, Melis; Adan Gökbulut, Aysun; Baran, Yusuf
    Chemotherapy is the main strategy for the treatment of cancer. However, the main problem limiting the success of chemotherapy is the development of multidrug resistance. The resistance can be intrinsic or acquired. The resistance phenotype is associated with the tumor cells that gain a cross-resistance to a large range of drugs that are structurally and functionally different. Multidrug resistance arises via many unrelated mechanisms, such as overexpression of energy-dependent efflux proteins, decrease in uptake of the agents, increase or alteration in drug targets, modification of cell cycle checkpoints, inactivation of the agents, compartmentalization of the agents, inhibition of apoptosis and aberrant bioactive sphingolipid metabolism. Exact elucidation of resistance mechanisms and molecular and biochemical approaches to overcome multidrug resistance have been a major goal in cancer research. This review comprises the mechanisms guiding multidrug resistance in cancer chemotherapy and also touches on approaches for reversing the resistance.
  • Article
    Citation - WoS: 20
    Citation - Scopus: 17
    Differentiation of Normal and Cancer Cell Adhesion on Custom Designed Protein Nanopatterns
    (American Chemical Society, 2015) Horzum, Utku; Özdil, Berrin; Pesen Okvur, Devrim
    Cell adhesion to the extracellular matrix is deregulated in metastasis. However, traditional surfaces used to study cell adhesion do not faithfully mimic the in vivo microenvironment. Electron beam lithography (EBL) is able to generate customized protein nanopatterns. Here, we used an EBL-based green lithography approach to fabricate homogeneous and gradient, single (fibronectin, K-casein) and double (fibronectin, laminin) active component protein nanopatterns with micrometer scale spacing to investigate differences in adhesion of breast cancer cells (BCC) and normal mammary epithelial cells (NMEC). Our results showed that as expected, in contrast to NMEC, BCC were plastic: they tolerated nonadhesion promoting regions, adapted to flow and exploited gradients better. In addition, the number of focal adhesions but not their area appeared to be the dominant parameter for regulation of cell adhesion. Our findings also demonstrated that custom designed protein nanopatterns, which can properly mimic the in vivo microenvironment, enable realistic distinction of normal and cancerous cell adhesion.