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Role of signaling pathways and redox processes in cancer cell biology
Vališ, Karel ; Kovář, Jan (advisor) ; Anděra, Ladislav (referee) ; Kozubík, Alois (referee)
5 identifikovali VDAC2 protein jako možný transportér železa do nádorových buněk a tudíž možný cíl protinádorové terapie. Abstract Specific apoptosis induction in cancer cells represents promising way of anticancer therapy without damaging healthy tissues. Hence, search for new molecular targets capable of specific apoptosis triggering is highly challenging, mainly due to new and effective anti-cancer therapies development. Cancer cell metabolism (1) and mainly mitochondrial metabolism (2) seems to represent intriguing target. Mitochondria play essential role in life of the cell but on the other hand mitochondria activate cell death which is usually connected to increased ROS (reactive oxygen species) production. Contribution of this work is identification of vitamin E analogues as inhibitors of complex II and potent inductors of mitochondrial ROS in cancer cells. Additionally, we have demonstrated activation of conserved Hippo/Mst1 kinase in response to the vitamin E analogues which results in FoxO1 nuclear localization, NOXA gene transactivation, Bak protein activation, mitochondrial membrane permeabilisation and apoptosis induction. Next we searched for membrane proteins with increased expression in cancer cells exposed to iron deprivation. These proteins can play a role in iron metabolism of cancer...
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The role of erbB-2 oncogene in the biology of cancer stem-like cells
Prokopová, Kateřina ; Neužil, Jiří (advisor) ; Anděra, Ladislav (referee)
Recent studies indicate the existence of a subpopulation of cells within tumours with stem cell-like characteristics. These "cancer stem-like cells" (CSCs) are relatively resistant to established therapies, usually targeting differentiated and fast proliferating cells. Therefore, CSCs may be a reason for the relapse of neoplastic diseases. CSCs can be characterised by a specific gene expression profile and deregulated signalling pathways. Of these, upregulation of the erbB-2 (HER2) receptor, a hallmark of ~25-30% breast cancer patients, is related to dismal prognosis, elevated proliferation potential and resistance to chemotherapy. Recent evidence has suggested that upregulation of erbB-2 leads to increase in the pool of CSCs. In our study we used mammospheres, cells grown in the absence of serum, an in vitro model of breast CSCs, which were prepared by "weaning" breast cancer MCF7 cells to a special medium. These cells were CD44high and showed increased expression of ABCG-2, Sox-2, Vimentin as well as high levels of erbB-2. Next, we prepared a stable line of MCF7 cells with low levels of erbB-2 by shRNA. ErbB-2low cells were characterised for expression of set of CSCs markers and tested for tumour forming efficacy in nude mice using ultrasound imaging. Keywords Cancer stem-like cells, erbB-2,...
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Immunogenic cancer cell death triggered by free and polymer bound doxorubicin
Kabešová, Martina ; Kovář, Lubomír (advisor) ; Anděra, Ladislav (referee)
Immunogenic cancer cell death triggered by free and polymer-bound doxorubicin Water-soluble polymeric drug carriers based on N-(2-hydroxypropyl) methacrylamide (HPMA) have been developed to avoid undesirable side-effects of systemically active cytostatic drugs. Conjugates based on HPMA copolymer passively accumulate in tumor tissue of solid tumors due to the effect of enhanced vascular permeability and retention effect (EPR effect). Active accumulation can be achieved by binding of targeting structure recognising tumor-specific receptors to the polymeric carrier. Conjugation of free doxorubicin to HPMA polymeric carrier significantly reduces its nonspecific side effects in vivo by maintaining effective antitumor activity in vitro and in vivo. Besides direct cytotoxic effect on tumor cells, HPMA conjugates with bound doxorubicin possess immunostimulatory properties and induce long-lasting anti-tumor immunity in cured mice. Recent studies have shown that free doxorubicin induce immunogenic apoptosis in tumor cells. Those cells are dying by cell death which possesses characteristic markers of apoptosis but these cells are able to activate the immune system and thus induce effective anti-tumor immune response. This phenomenon has been described as crucial for a development of treatment-induced...
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Promyelocytic leukemia protein function in normal, tumor and senescent human cells
Rossmeislová, Lenka ; Hozák, Pavel (advisor) ; Forstová, Jitka (referee) ; Anděra, Ladislav (referee)
Promyelocytic leukemia protein (PML) gene encodes a nuclear protein localizing into the nucleoplasm and distinct nuclear bodies, referred to as PML nuclear bodies (PML NBs). PML is now considered as a gene with tumor-suppressive properties since it is implicated in many nuclear functions affecting cellular proliferation, apoptosis and senescence. The presented work is a part of a larger project that aims to clarify the regulation of promyelocytic leukemia protein expression and investigates the role of PML protein in cellular senescence. The specific goals of my PhD project were to evaluate new in vitro models for the study of PML, to elucidate the effects of histone deacetylase inhibitors on PML gene expression, and to investigate the association of PML with the nucleolus.
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Role of DD- and DED-containing adaptor proteins in apoptotic signaling
Čaja, Fabián ; Janštová, Vanda (referee) ; Anděra, Ladislav (advisor)
Proteins containing a bundle of six anti-paralel α-helices in so-called "death domain" (DD) and similar structures (DED, CARD) represent important players in apoptotic signaling. To DD/DED/CARD domains-containing proteins belong pro- apoptotic membrane receptors from the TNFR superfamily, then adaptor proteins and enzymes as proteases or kinases. These pro-apoptotic "death receptors" interact with adaptor proteins and initiator caspases containing DDs or DEDs and activate apoptotic signaling cascade. DEDs and DDs are in addition found in many proteins participating in activation of caspases or other non-apoptotic signaling. Many experimental models document that defects in and deregulations of proteins containing DDs and DEDs can have severe if not lethal consequences for an organism. Abberations in these proteins in many cases could lead to cancerogenesis, immunodeficiencies or developmental defects.
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TRAIL-induced Apoptosis in Populations of Colon Cancer Cell Lines under Various Cultivation Conditions
Nevařil, Leonard ; Anděra, Ladislav (advisor) ; Neužil, Jiří (referee)
Tumor Necrosis Factor-Related Apoptosis Inducing Ligand (TRAIL) is a cytokine of TNF family, which participates in the non-exclusive regulation of survival and proliferation of mainly hematopoietic cells. Shortly after its discovery it also brought significant attention as specific and potent inducer of apoptosis of cancer cells of various origins, and since then it has been investigated as a potential novel anti-tumor therapeutics. Recently, cancer stem cells (CSCs) were suggested to be a distinct subset of tumor cells that could be responsible at least in some tumors for their sustainment, recurrence and drug resistance. These cells in the "hierarchic" model of tumorigenesis thus represent an important and attractive target for efficient tumor therapy. In this study we use several colorectal adenocarcinoma cell lines as an experimental model for the analysis of CSC-prone cultivation conditions on TRAIL-induced apoptosis of these cells. For enrichment of eventual cancer stem cells we cultivated cell lines in a serum-free medium, originally developed for cultivation of neural stem cells, and assessed the expression of putative CSC markers CD133 and ABCG2 by flow cytometry (FACS). Simultaneously, we tested the expression of TRAIL receptors and susceptibility to TRAIL-induced apoptosis in these cells. We...
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