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Characterization and modulation of MitoTam-induced cell death in breast carcinoma cells
Hrysiuk, Mariia ; Anděra, Ladislav (advisor) ; Dráber, Peter (referee)
Although recent years brought many breakthrough discoveries in anti-cancer research and therapy, malignant diseases such as breast cancer (BC) still present one of the major health threats worldwide. Cancer cells usually gain resistance to the activation of regulated cell death (RCD) modalities such as caspase-dependent apoptosis. Among novel RCD-inducing agents belongs to mitochondria-targeted tamoxifen - MitoTam, which is also the major focus of this Thesis. In a panel of BC cells, we determined the energetic (mitochondrial respiration vs. glycolysis) and major RCD-related proteins (Western blotting) profiles, and using Lumascope LS720-assisted time-lapse monitoring we analyzed their sensitivity to MitoTam-induced RCD. We found out that glycolysis-preferring BC cells as MDA-MB-231 are more resistant to MitoTam treatment than mitochondrial respiration-biased MDA-MB-453 cells. However,the majority of tested BC cells can be sensitized to MitoTam by BH3 mimetics such as BCL-XL targeting A1155463 and some cellular metabolism-modulating compounds such as lactate dehydrogenase inhibitor (R)-GNE-140, especially in the pre-treatment regime. Also, other metabolism-modulating compounds such as Pyruvate Dehydrogenase Kinases inhibitor JX06 potently enhanced the efficacy and kinetics of MitoTam-induced RCD....
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Role of cFLIP/CFLAR protein in the activation and regulation of cell death
Ksandrová, Marie ; Anděra, Ladislav (advisor) ; Macůrková, Marie (referee)
Programmed cell death as a natural mechanism plays essential role in development and homeostasis maintenance through removal of damaged, unwanted or dangerous cells. The cell death is an irreversible proces must be strictly regulated and thus defects in the regulation of cell death could lead to serious/fatal diseases. There are also one of the reasons why cell death regulating mechanisms are subjects of intense research nowadays. c-FLIP is one of several important cell death regulators. Three distinct isoforms of c-FLIP were detected on the protein level in human organism (long c-FLIPL and two shorter variants c-FLIPS and c-FLIPR) that interact their main cellular partner procaspase 8. The functional consequences of their interaction (enhancement or suppression of procaspase 8 selfprocessing) depend on the cellular level of c-FLIP, expressed splice variants and extracellular signaling. As c-FLIP is an important component of cell death signaling pathways (apoptosis and regulated necrosis), its expression and functional posttranslational modifications are strictly regulated by several mechanisms. Upregulation of c-FLIP levels has been found in various types of tumor cells that are often resistant to anticancer treatment.
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Programmed necrosis: its activation, regulation and role in cellular physiology.
Rytířová, Markéta ; Anděra, Ladislav (advisor) ; Holzerová, Kristýna (referee)
Cell death as the final stage of cell existence can be either triggered accidently or it can result from the activation of specific controllable signalling pathways. Regulated or programmed cell death can be induced by number of extrinsic or intrinsic stimuli under both physiological and pathological conditions. For a long time, caspase-dependent apoptosis has been considered as the only form of programmed cell death. However, in the last 10 years it has been shown and proofed that also necrotic cell death, formally considered as random and uncontrollable cell death, may also proceed in controllable manner with specific signalling pathways and features. Among the signalling pathways associated with the programmed necrosis belong activation of RIP1/RIP3 kinase-containing necrosome, then cyclophilin D assisted mitochondrial permeabilization or response to oxidative stress. To the most studied signal transduction pathways associated with the iniciation of programmed necrosis belongs TNF-mediated activation of RIP1/RIP3-dependent necroptosis. Programmed necrosis plays an important role in various physiological and pathological processes, for example in ischemic-reperfusion disorders, diseases of the eye, skin, gastrointestinal system, and also can be triggered in cancer therapy. Key words Cell death,...
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