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Mechanisms of resistance and iron metabolism in cancer stem cells
Lettlová, Sandra ; Truksa, Jaroslav (advisor) ; Kovář, Jan (referee) ; Brábek, Jan (referee)
(EN) Analogously to normal stem cells within the tissues, cancer stem cells (CSCs) have been proposed to be responsible for maintenance and growth of tumours. CSCs represent a small fraction of cells within the tumour, which is characterised by self-renewal capacity and ability to give rise to a tumour when grafted into immunocompromised mice. Cells with increased stemness properties are believed to be responsible for tumour resistance, metastases formation and relapse after tumour treatment. The first part of this work concentrates on resistance of the tumours, which is often associated with increased expression of ATP-binding cassete (ABC) transporters pumping chemotherapeutics out of the cells. For the purposes of this study, we utilized an in vitro model of CSCs, based on cultivation of cells as 3D "spheres". Expression profiling demonstrates that our model of CSCs derived from breast and prostate cancer cell lines express higher mRNA level of ABC transporters, particularly ABCA1, ABCA3, ABCA5, ABCA12, ABCA13, ABCB7, ABCB9, ABCB10, ABCC1, ABCC2, ABCC3, ABCC5, ABCC8, ABCC10, ABCC11 and ABCG2 among the cell lines tested. The protein level of ABC transporters tested in breast CSCs showed higher expression of ABCB8, ABCC1, ABCC2, ABCC10 and ABCG2 but downregulation of ABCB10 and ABCF2 proteins....
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Biological behavior of ovarian carcinoma and its relation to therapy
Bartáková, Alena ; Bouda, Jiří (advisor) ; Špaček, Jiří (referee) ; Svoboda, Tomáš (referee)
Structured abstract Hypothesis Cancer stem cells (CSCs) are subpopulations of cells which could contribute to tumor growth, metastasis formation and chemoresistance. CSCs can be detected by surface markers assessed by immunohistochemistry methods. A typical surface marker for CSCs is CD44 (standard form). We assumed, that CD44(s) could serve as a prognostic factor and marker of chemoresistance in patients with epithelial ovarian cancer. The aim of study 1. To recruit group of patients with histologically verified epithelial ovarian carcinoma. 2. To evaluate prognostic significance of known prognostic factors in our series of patients. 3. To assess the expression of CD44 in specimens of primary tumors and specimens of implantation metastasis using immnunohistochemistry and analyze their correlation. 4. To evaluate the expression of CD44 in relation to known prognostic factors. To analyze the significance of CD44 expression evaluation for overall survival, disease-free interval and chemoresistance. To find CD44 positivity cut-off by using statistical methods Materials and Methods A retrospective study was performed on 87 patients with histologically verified EOC. All patients were tested for primary tumor specimens, 48 of them were tested with regard to both specimens of primary tumor and implantation...
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Cell surface CD47 expression in cancer stem cell-targeted tumor therapy
Kuzmík, Ján ; Drbal, Karel (advisor) ; Černý, Jan (referee)
CD47 is a transmembrane glycoprotein with a high expression in both, healthy and cancer (stem) cells. Level of the CD47 expression is negatively correlated with survival of cancer patients. Binding of CD47 to SIRPα, localized on a phagocyte, triggers intracellular signaling cascade. The final effect of this cascade is dephosphorylation of nonmuscle myosin-IIA, which disrupts its function and accumulation to phagocytic synapse. The blockage of CD47-SIRPα signaling pathway in a presence of the pro-phagocytic signal induces phagocytosis of cancer cells. Afterwards, phagocytes can serve as the antigen presenting cells and prime T cell response. Role of CD47-SIRPα signaling pathway in immunity has established this pathway as a target of cancer therapy testing. Preclinical research has identified a positive therapeutic effect of blocking this signaling pathway. Nowadays, the first phase of clinical trials is being conducted. The most prevalent approach of blocking CD47-SIRPα signaling pathway in therapy is the use of anti-CD47 blocking monoclonal antibodies, which cause mild anemia. However, alternative approaches of blocking this pathway are also being developed. In this bachelor thesis, I have summarized the research related to the blockage of CD47-SIRPα signaling pathway as a cancer therapy.
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Detection and clonogenic assay of cancer stem-like cells using flow cytometry
Fedr, Radek ; Souček, Karel (advisor) ; Vaňhara, Petr (referee)
The Diploma Thesis deals with an implementation of the new method for an assessment of a cloning efficiency of the cancer stem cells separated by a high speed cell sorter. The cell-sowing on the microtitration plates was performed by the flow cytometry method in a combination with the high speed cell sorter. In the first part of the Diploma Thesis the new method was introduced and tested on the selected cell lines. The obtained results were compared with the results of the limiting dilution assay within four cell lines. As for the second part of my Diploma Thesis, the method was practically applied to analysis of the cloning capacity of two subpopulations of cE2 cells based on the expressions of characteristic markers of stem and cancer stem cells - CD44 and CD 133. Based on the findings, the new method can be introduced as an approved proceeding for the cloning capacity assessment of cancer stem cells in other workplaces that possess analogical device equipment.
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Characterisation of the cell line TRAMP-C2 side population, mouse model of prostate cancer
Žlabová, Anna ; Reiniš, Milan (advisor) ; Šmahel, Michal (referee)
Side population is a minor subpopulation (SP) of some cell lines, exporting staining dye Hoechst 33342 out of their cytoplasm. It is discussed as a possible source of "cancer stem cells", "tumour initiating cells" or "metastasis initiating cells". However, broad literature suggest, that stemness and other privileged properties of SP are very variable between different cell types, cell lines and stage of disease. Cell lines TRAMP are the only widely available murine models for testing of prostate cancer therapy. We noticed in literature a mention about existence of 1-2% of cells constituting side population, but detailed characteristic have not been described until now. In this diploma thesis, we worked on characterisation of SP of the TRAMP-C2 cell line in comparison to other cells (nonSP). In the first part, we compared stem properties of SP and nonSP. We started with checking the existence of SP by its verapamil sensitivity. Using mRNA analysis, we showed that neither SP nor nonSP have increased c-Kit expression and that there are no differences in Bmi-1 expression. We found that SP is heterogenic mixture of CD24-CD44-, CD24-CD44+ and CD24+CD44+ cells, while nonSP is almost solely CD24-CD44+. We documented that SP and nonSP returned back to original SP ratio during cultivation. Then we showed on...
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