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Molecular mechanisms responsible for regulation of apoptosis in prostate cancer cells treated with TRAIL and chemotherapeutic drugs
Tománková, Silvie ; Hyršlová Vaculová, Alena (advisor) ; Špegárová, Jarmila (referee)
Prostate cancer is one of the most common cancer-related causes of death among men. Chemotherapy is mainly used for treatment of its later stages, accompanied by unpleasant side effects. So far, the treatment of advanced stages of prostate cancer has not been sufficient, and new more effective alternatives are needed. The application of the TRAIL cytokine, which induces apoptosis in tumor cell, but is not toxic to nonmalignant cells, seems to be a promissing approach. However, TRAIL-based therapy is often limited by the emerging cancer cell resistance. Overcoming the resistance can be achieved by combination therapy of TRAIL with effective sensitizers. Within this work, a combination of TRAIL with platinum-based chemotherapeutic drugs such as cisplatin or its novel derivative LA-12 was applied in order to facilitate the elimination of prostate cancer cells. In the experimental part of this work, using Western blot and flow cytometry analysis it was shown that TRAIL in combination with CDDP or LA-12 effectively enhanced apoptosis in three human prostate cancer cell lines. This effect was accompanied with increased activation/amount of several proapoptotic Bcl-2 family proteins, while no changes in the level of the receptors for TRAIL were observed. These results demonstrated that especially the combination...
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Molecular mechanisms of tumor pathogenesis of Hedgehog signaling pathway in selected tumor types
Kreisingerová, Kateřina ; Vachtenheim, Jiří (advisor) ; Macůrek, Libor (referee) ; Uldrijan, Stjepan (referee)
The presented doctoral thesis is focused on the role of the Hedgehog (HH) signaling pathway in cancer pathogenesis. HH signaling pathway is an evolutionarily conserved signaling pathway that plays an essential role in embryonic development. Its activity is strictly limited to stem and progenitor cells for example in brain, lung, skin or prostate. HH pathway also plays a key role in tissue homeostasis and regeneration. Aberrantly activated HH pathway is essential in cancer progression. The aim of the presented thesis was to elucidate new details about the HH signaling pathway. We identified a new target gene of the HH pathway - the anti-apoptotic protein survivin. Survivin is considered to be an important tumor marker associated with a poor prognosis of patients. We showed that the inhibitor of HH pathway effectors GLI1 and GLI2 GANT61 reduced the survivin level in cancer cells. Subsequently, we used GANT61 and the inhibitor of the anti-apoptotic BCL2 protein family obatoclax to inhibit melanoma cells growth. We showed that the combination of these inhibitors was very effective in the eradication of melanoma cells in vitro. We also proved that GANT61 triggers the process of apoptosis in melanoma cells. We found out that the HH signaling pathway is canonically activated in many cell lines of various...
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