Master Degree / Yüksek Lisans Tezleri

Permanent URI for this collectionhttps://hdl.handle.net/11147/3008

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2014 - 20153

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Subject: search.filters.subject.Breast--Cancer

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Now showing 1 - 3 of 3
  • Master Thesis
    Role of Irf6 in Notch Regulated Apoptosis, Cell Cycle and Differentiation in Breast Epithelial Cells
    (Izmir Institute of Technology, 2015) Ekinci, Burcu; Yalçın Özuysal, Özden
    Notch pathway, an evolutionarily conserved signaling, controls development, differentiation and proliferation. Notch1 and Notch4 activation caused mammary tumor formation showing an oncogenic effect. Overexpression of Notch1 can also supress proliferation in breast epithelial cells depending on dosage and cell type. Thus, Notch can act as an oncogene or tumor suppressor in breast. IRF6, a member of interferon regulatory factor family, has a role in development and differentiation of the epidermis, downstream of Notch signaling. IRF6 overexpression induces cell cycle arrest in breast cancer cells showing a tumor suppressor role. It was recently identified that IRF6 is a mediator of Notch in proliferation and transformation of breast epithelial cells. In this study, it was aimed to identify whether IRF6 has any effect on cell cycle regulation, apoptosis and breast cancer stem cell population (BCSCs) under Notch and whether IRF6 has a role in expression of luminal and basal markers in breast cell lines. Our results showed that IRF6 knockdown in normal breast epithelial cell line, MCF10A, reduced percentage of cells in S-phase, which was increased by Notch activation. IRF6 knockdown induced early apoptosis and reduced BCSCs, however it has no effect downstream of Notch in these processes. On the other hand, IRF6 did not play an essential role on expression of luminal and basal markers. In conclusion, our previous observation was supported that IRF6 is a mediator of Notch in cell proliferation. Furthermore, these data showed that IRF6 has a novel role on early apoptosis and stem cell population independent of Notch signaling.
  • Master Thesis
    Invadopodia Formation on Nanometer Scale Protein Patterns
    (Izmir Institute of Technology, 2014) Batı, Gizem; Pesen Okvur, Devrim; Özyüzer, Lütfi
    How the positions of invadopodium in the cell are determined and if they have an adhesivefunction are not known. Using fluorescence microscopy and antibodies that recognize actin, cortactin and MT1-MMP proteins, invadopodia formed by breast cancer cells plated on protein nanopatterns of different geometeries and components after stimulation with epidermal growth factor which is known to induce invadopodia formation, were examined. Invadopodia formation was studied for the first time on nanometer scale, single and double active component, protein patterns with equal distance and gradient spacings. The results show that: • On K-casein-fibronectin nanopatterns, invadopodia prefer to form on K-casein which blocks cell adhesion rather than on fibronectin nanodots which promote cell adhesion. • On Laminin-fibronectin nanopatterns, invadopodia prefer to form on laminin rather than on fibronectin nanodots. • On gradient patterns, invadopodia prefer areas with wide spacings. These results support the hypotheses that the positions where invadopodia form can be determined by surface protein nanopatterns and that cell adhesion is not required at points where invadopodia will form.
  • Master Thesis
    Cell Adhesion on Nanomater Scale Fibronectin Patterns: a Comparision of Breast Cancer Cells and Normal Breast Epithelial Cells
    (Izmir Institute of Technology, 2014) Horzum, Utku; Pesen Okvur, Devrim
    Cell adhesion to extracellular matrix is an important process for both health and disease states. Surface protein patterns are topographically flat, and do not introduce other chemical, topographical or rigidity related functionality and, more importantly, that mimic the organization of the in vivo extracellular matrix are desirable. Previous work showed that vinculin and cytoskeletal organization are modulated by the size and shape of surface nanopatterns. However, a comparative and quantitative analysis on normal and cancerous cell morphology and focal adhesions as a function of micrometer scale spacings of protein nanopatterns was absent. Here, electron beam lithography was used to pattern fibronectin (FN) nanodots with micrometer scale spacings on a K-casein background (single active) on indium tin oxide (ITO) coated glass which, unlike silicon, is transparent and thus suitable for many light microscopy techniques. Exposure times were significantly reduced using the line exposure mode with micrometer scale step sizes. Micrometer scale spacings of 2, 4, 8 microns and gradients between FN nanodots modulated cell adhesion for both breast cancer and normal mammary epithelial cells, through modification of cell area, cell symmetry, actin organization, focal adhesion number, size and circularity under both static and flow conditions. Overall, cell behavior was shown to shift at the apparent threshold of 4 μm spacing. Results showed that there were significant differences in terms of cell adhesion between breast cancer and normal mammary epithelial cells: Breast cancer cells exhibited a more dynamic and flexible adhesion profile than normal mammary epithelial cells.